CN113858980B - Electric vehicle, charging and discharging device and control method thereof - Google Patents

Abstract

The invention provides an electric vehicle, a charging and discharging device and a control method thereof, wherein the control method comprises the following steps: when a first instruction is received, judging whether the first instruction is a charging instruction or a discharging instruction; and under the condition that the first instruction is a charging instruction, controlling the on and off of the first bidirectional switch unit and the second bidirectional switch unit to convert the power grid alternating current signal input from the external charging port into a first alternating current signal, and controlling the on and off of the rectification inversion module to convert the first alternating current signal into a direct current signal and charge the power battery through the direct current signal, wherein the voltage corresponding to the first alternating current signal is higher than the voltage corresponding to the power grid alternating current signal. The invention can control the current direction of the power factor correction module, has high control reliability on the power factor correction module, has simple control scheme on the charge and discharge device, and is convenient for reducing the control cost and improving the control efficiency.

Description

Electric vehicle, charging and discharging device and control method thereof

technical field

The invention relates to the technical field of electric vehicles, in particular to a control method of a charging and discharging device, a charging and discharging device and an electric vehicle.

Background technique

At present, with the commercialization progress of electric vehicles, the on-board charger has become an important structure of electric vehicles. The on-board charger is used to convert the alternating current of the grid into direct current to charge the power battery in the electric vehicle.

In the related art, the on-board charger includes an AC circuit and a high-voltage DC circuit, wherein the AC circuit includes a power factor correction circuit composed of six MOS transistors, the body diodes of the six MOS transistors conduct in the same direction, and the high-voltage DC circuit includes a first transformer , the rectification topology corresponding to the primary coil of the first transformer and the rectification topology corresponding to the secondary coil of the first transformer.

However, there are still the following problems in the process of controlling the AC circuit of the vehicle charger in the related art: after the MOS tube is turned on in the control power factor correction circuit, if the voltage difference between the two ends of the MOS tube changes from a positive voltage difference to a negative voltage The current direction of the MOS tube is reversed, that is, the current direction of the MOS tube cannot be controlled to maintain the required current direction, and the control reliability of the power factor correction circuit is poor; in addition, due to The high-voltage DC circuit in the related art on-board charger requires two rectification topologies. The related art on-board charger has a complex structure and many components, which leads to complex control schemes for the on-board charger, high control costs, and low control efficiency.

Contents of the invention

In view of the above problems, the purpose of the embodiments of the present invention is to provide an electric vehicle, a charging and discharging device and a control method thereof, so as to solve the problems of poor control reliability and complex control schemes in the control scheme of the on-board charger in the related art.

In order to solve the above problems, an embodiment of the present invention discloses a control method for a charging and discharging device, the charging and discharging device includes a sequentially connected power factor correction module, a transformer, and a rectification and inverter module for charging or discharging a power battery, The transformer includes a first winding, a second winding, and a third winding, the first winding and the second winding are connected in series, and the power factor correction module includes a first bidirectional switch unit, a second bidirectional switch unit, and an inductor unit, the first end of the first bidirectional switch unit is connected to the first end of the first winding connected in series with the second winding, the first end of the second bidirectional switch unit is connected to the first winding connected in series with the second end of the second winding, the second end of the first bidirectional switch unit and the second end of the second bidirectional switch unit are connected to the first end of the inductance unit, the The second end of the inductance unit is connected to the first end of the external charging port, the midpoint of the series connection between the first winding and the second winding is connected to the second end of the external charging port, and the rectification and inverter module is connected to the second end of the external charging port. The third winding is connected; the control method includes:

When receiving the first instruction, judging whether the first instruction is a charging instruction or a discharging instruction;

When the first instruction is the charging instruction, the first bidirectional switch unit and the second bidirectional switch unit are controlled to be turned on and off, so as to exchange the power grid input from the external charging port Convert the signal into a first AC signal, and control the on and off of the rectification and inverter module, so as to convert the first AC signal into a DC signal, and charge the power battery through the DC signal, wherein , the voltage corresponding to the first AC signal is higher than the voltage corresponding to the grid AC signal.

In order to solve the above problems, the embodiment of the present invention also discloses a charging and discharging device, including a controller, a power factor correction module connected in sequence, a transformer, and a rectification and inverter module, and the controller is used to control the power factor correction module and The rectification and inverter module is used to realize the above-mentioned control method of the charging and discharging device. .

In order to solve the above problems, an embodiment of the present invention also discloses an electric vehicle, including the above charging and discharging device.

The embodiment of the present invention has the following advantages: since the power factor correction module in the charging and discharging device includes a first bidirectional switch unit and a second bidirectional switching unit, the control method of the charging and discharging device in the embodiment of the present invention is a charging command when the first instruction is In the case of control the on and off of the first bidirectional switch unit and the second bidirectional switch unit to convert the grid AC signal input from the external charging port into the first AC signal, not only can realize the power of the power factor correction module Factor correction function, at the same time, it can ensure that the direction of the current flowing through the first bidirectional switch unit and the second bidirectional switch unit is consistent with the conduction direction, that is, to realize the control of the current direction of the power factor correction module, and the control of the power factor correction module is reliable. In addition, because the transformer in the charging and discharging device is arranged between the power factor correction module and the rectification and inverter module, compared with the vehicle charger in the related art, at least the rectification topology corresponding to the primary coil of the transformer can be reduced, effectively simplifying the The circuit structure is improved and the number of components is reduced. Therefore, the control method of the charge-discharge device in the embodiment of the present invention only needs to control the first bidirectional switch unit, the second bidirectional switch unit, and the rectifier and inverter in the simplified structure of the charge-discharge device. Modules are used for control, and the control scheme is simpler, which is convenient for reducing control costs and improving control efficiency.

Description of drawings

Fig. 1 is a flow chart of the steps of an embodiment of a control method of a charging and discharging device of the present invention;

Fig. 2 is a structural block diagram of an embodiment of a charging and discharging device of the present invention;

3 is a schematic structural view of an embodiment of a charging and discharging device of the present invention;

Fig. 4 is a flow chart of the steps of another embodiment of the control method of the charging and discharging device of the present invention;

5 is a schematic diagram of the current direction of the charging and discharging device in step S22 in another embodiment of the control method of the charging and discharging device of the present invention;

6 is a schematic diagram of the current direction of the charging and discharging device in step S24 in another embodiment of the control method for the charging and discharging device of the present invention;

7 is a schematic diagram of the current direction of the charging and discharging device in step S31 in another embodiment of the control method for the charging and discharging device of the present invention;

8 is a schematic diagram of the current direction of the charging and discharging device in step S33 in another embodiment of the control method for the charging and discharging device of the present invention;

Fig. 9 is a schematic structural view of another charging and discharging device embodiment of the present invention;

FIG. 10 is a flow chart of steps in another embodiment of a control method for a charging and discharging device according to the present invention.

Detailed ways

In order to make the above objects, features and advantages of the present invention more comprehensible, the present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

Referring to FIG. 1 , it shows a flow chart of the steps of an embodiment of a control method for a charging and discharging device according to the present invention, which may specifically include the following steps:

Step S10, when the first instruction is received, it is judged whether the first instruction is a charging instruction or a discharging instruction.

Specifically, step S10 may use any manner to determine whether the first instruction is a charging instruction or a discharging instruction.

Specifically, as shown in FIG. 2, the charging and discharging device 10 may include: a sequentially connected power factor correction module 1, a transformer 2, and a rectification and inverter module 3 for charging or discharging the power battery. The transformer 2 includes a first winding, The second winding and the third winding, the first winding and the second winding are connected in series, the power factor correction module 1 includes a first bidirectional switch unit 11, a second bidirectional switch unit 12 and an inductance unit 13, the first bidirectional switch unit 11 The first One end is connected to the first end after the first winding and the second winding are connected in series, the first end of the second bidirectional switch unit 12 is connected to the second end after the first winding and the second winding are connected in series, and the first bidirectional switch unit 11 The second end of the second end and the second end of the second bidirectional switch unit 12 are connected to the first end of the inductance unit 13, the second end of the inductance unit 13 is connected to the first end of the external charging port 20, the first winding and the second winding The midpoint of the series connection is connected to the second end of the external charging port 20, and the rectification and inverter module 3 is connected to the third winding.

Specifically, the bidirectional switch unit (the first bidirectional switch unit 11 or the second bidirectional switch unit 12) has three states, namely an off state, a first conduction state and a second conduction state, wherein, in the first conduction state , the bidirectional switch unit conducts in the first conduction direction, allowing the current direction to flow through to be the same as the first conduction direction, and in the second conduction state, the bidirectional switch unit conducts in the second conduction direction, allowing the current flowing through The current direction is the same as the second conduction direction, wherein the first conduction direction is opposite to the second conduction direction. In this way, the control method of the charging and discharging device according to the embodiment of the present invention only needs to control the conduction states of the first bidirectional switch unit 11 and the second bidirectional switch unit 12 to realize the control of the first bidirectional switch unit 11 and the second bidirectional switch unit. 12 allows the direction of the current flowing through to realize the control of the current direction of the power factor correction module 1, and the control reliability of the power factor correction module is high.

Specifically, the inductance unit 13 is used to store electric energy or release the stored electric energy during the working process of the power factor correction module 1, so as to raise the charging circuit where the power factor correction module 1 is located when the power grid charges the power battery through the charging and discharging device 10. The voltage can realize high-voltage transmission of electric energy, which is convenient for improving the charging efficiency of the charging and discharging device 10, shortening the charging time, and reducing the voltage of the discharging circuit where the power factor correction module 1 is located during the process of discharging the power battery through the charging and discharging device 10 to the grid. The output voltage of the discharge circuit is matched with the grid voltage.

In FIG. 2 , the power factor correction module 1 can be used to perform power factor correction and voltage boost on the voltage and current of the grid AC signal input from the external charging port 20 into a first AC signal, and transmit the first AC signal to the first AC signal. winding or secondary winding. Furthermore, the first winding or the second winding transmits the first AC signal to the third winding. The power factor correction module 1 can also be used to perform power factor correction on the first AC signal input by the first winding or the second winding and reduce the voltage to the grid AC signal, and transmit the grid AC signal to the grid or AC load, so as to control the grid supply or supply power to AC loads.

In Fig. 3, the rectification and inverter module 3 can be used to rectify the first AC signal transmitted by the third winding into a DC signal, and output the DC signal to the power battery 30 to charge the power battery 30, and the rectification and inverter module 3 can be used to invert the DC signal output by the power battery 30 into a first AC signal, and transmit the first AC signal to the third winding. Furthermore, the third winding transmits the first AC signal to the first winding or the second winding to discharge the power battery 30 .

Step S20, when the first instruction is a charging instruction, control the on and off of the first bidirectional switch unit and the second bidirectional switch unit, so as to convert the grid AC signal input from the external charging port into a first AC signal , and control the turn-on and turn-off of the rectifier and inverter module to convert the first AC signal into a DC signal, and charge the power battery through the DC signal, wherein the voltage corresponding to the first AC signal is higher than that corresponding to the grid AC signal Voltage.

Optionally, the external charging port may be a charging port of an external charging pile or a charging port of other equipment that can input grid AC signals.

Optionally, as shown in FIG. 3, the first bidirectional switch unit 11 may be a first bidirectional switch device, and the second bidirectional switch unit 12 may be a second bidirectional switch device. Therefore, the first bidirectional switch unit 11 and the second bidirectional switch unit The switch unit 12 has a simple structure and requires few components.

Since the power factor correction module in the charging and discharging device includes a first bidirectional switch unit and a second bidirectional switching unit, the control method of the charging and discharging device in the embodiment of the present invention controls the first bidirectional switching unit when the first instruction is a charging instruction. The switch unit and the second bidirectional switch unit are turned on and off to convert the grid AC signal input from the external charging port into the first AC signal, which can not only realize the power factor correction function of the power factor correction module, but also ensure the current The direction of the current passing through the first bidirectional switch unit and the second bidirectional switch unit is consistent with the conduction direction, that is, the control of the current direction of the power factor correction module is realized, and the control reliability of the power factor correction module is high; The transformer is arranged between the power factor correction module and the rectification and inverter module. Compared with the car charger in the related art, at least the rectification topology corresponding to the primary coil of the transformer can be reduced, which effectively simplifies the circuit structure and reduces the number of components. Therefore, the control method of the charging and discharging device in the embodiment of the present invention only needs to control the first bidirectional switching device, the second bidirectional switching device and the rectification and inverter module in the charging and discharging device with a simplified structure, and the control scheme is simpler and convenient Reduce control costs and improve control efficiency.

Optionally, the frequency of the first AC signal may be greater than the frequency of the AC signal of the grid, so as to realize the transmission of AC signals at high frequency and high voltage (the voltage corresponding to the first AC signal is higher than the voltage corresponding to the AC signal of the grid), and improve the charging and discharging device 10. Excellent energy transmission efficiency, shortening the energy transmission time.

Optionally, as shown in FIG. 3 , the charging and discharging device 10 of the embodiment of the present invention may also include a rectifying module 4 for charging the battery 40, the transformer 2 may also include a fourth winding, and the rectifying module 4 is connected to the fourth winding . When the functions of the vehicle-mounted DC converter and the vehicle-mounted charger are integrated in a charging circuit in the related art, the vehicle-mounted DC converter is arranged in the low-voltage DC circuit in the charging circuit, and the low-voltage DC circuit includes the second transformer, the second transformer The rectification topology corresponding to the primary coil and the rectification topology corresponding to the secondary coil of the second transformer, while the charging and discharging device 10 in the embodiment of the present invention can realize the integration of the functions of the vehicle-mounted DC converter and the vehicle-mounted charger with only one transformer 2 In one circuit (that is, the power factor correction module 1, the rectification and inverter module 3 for charging or discharging the power battery 30 and the rectification module 4 for charging the storage battery 40 are integrated in one circuit), and since the transformer 2 is set in Between the power factor correction module 1 and the rectification module 4, the rectification module 4 only needs one rectification topology, the structure of the rectification module 4 is simpler, and the number of required components is less. solution, the control method of the charge and discharge device in the embodiment of the present invention only needs to control the first bidirectional switch unit 11, the second bidirectional switch unit 12, the rectification and inverter module 3 and the rectification module 4 in the charge and discharge device 10 with a simplified structure , the control scheme is simpler, which is convenient for reducing control cost and improving control efficiency.

In FIG. 3 , the power factor correction module 1 can be used to perform power factor correction and voltage boost on the voltage and current of the grid AC signal input from the external charging port 20 into a first AC signal, and transmit the corrected first AC signal to the primary winding or the secondary winding. Furthermore, the first winding or the second winding transmits the corrected first AC signal to the fourth winding or the third winding. The power factor correction module 1 can also be used to perform power factor correction on the first AC signal input by the first winding or the second winding and reduce the voltage to the grid AC signal, and transmit the grid AC signal to the grid or AC load, so as to control the grid supply or supply power to AC loads.

In Fig. 3, the rectification and inverter module 3 can be used to rectify the first AC signal transmitted by the third winding into a DC signal, and output the DC signal to the power battery 30 to charge the power battery 30, and the rectification and inverter module 3 can be used to invert the DC signal output by the power battery 30 into a first AC signal, and transmit the first AC signal to the third winding. Furthermore, the third winding transmits the first AC signal to the first winding or the second winding or the fourth winding to discharge the power battery 30 .

In FIG. 3 , the rectification module 4 is used to rectify the first AC signal input by the fourth winding into a DC signal to charge the battery 40 .

In Fig. 3, the rectification and inverter module 3 may include four fifth switching tubes and a first capacitor unit for connecting with the power battery 20, the four fifth switching tubes form a first full-bridge topology, and the first full-bridge topology and The first capacitor units are connected in parallel, and the first full bridge topology is connected with the third winding. Wherein, the first capacitor unit is used for filtering the signal output by the first full bridge topology, and for filtering the signal output by the power battery 20 . Optionally, as shown in FIG. 3 , the four fifth switch transistors may be MOS transistors Q5, MOS transistors Q6, MOS transistors Q7 and MOS transistors Q8, and the first capacitor unit may be a first capacitor C1.

In FIG. 3 , the rectification module 4 may include a rectification unit 41 and a second capacitor unit for connecting with the battery 30 , the rectification unit 41 is connected in parallel with the second capacitor unit, and the rectification unit 41 is connected with the fourth winding. The second capacitor unit is used for filtering the signal output by the rectification unit 41 . In FIG. 3, the second capacitor unit may be a second capacitor C2.

In FIG. 3, the rectifier unit 41 may include four sixth switch tubes, and the four sixth switch tubes form a second full-bridge topology, or, the number of the fourth windings may be two, and the two fourth windings are connected in series to rectify Module 4 may include a seventh switch tube and an eighth switch tube, the seventh switch tube is connected to one of the fourth windings and the second capacitor unit, the eighth switch tube is connected to the other fourth winding and the second capacitor unit, and the seventh switch tube is connected to the second capacitor unit. The switch tube and the eighth switch tube form a full-wave rectification topology. That is, the rectification unit 41 can rectify the AC signal input by the fourth winding into a low-voltage DC signal through the second full-bridge topology or the full-wave rectification topology, so as to charge the battery 30 . In FIG. 3 , the four sixth switch transistors may be MOS transistor Q9 , MOS transistor Q10 , MOS transistor Q11 and MOS transistor Q12 .

In FIG. 3 , the power factor correction module 1 may also include a third capacitor unit for connecting to the power grid, the first end of the third capacitor unit is connected to the second end of the inductance unit 13, and the second end of the third capacitor unit is connected to the second end of the inductor unit 13. The midpoints of the series connection of the first winding and the second winding are connected. Specifically, the third capacitor unit is used for filtering the AC signal input to the grid and the AC signal input from the grid. In FIG. 3 , the third capacitor unit may be a third capacitor C3, and the inductor unit 13 may be an inductor L1.

Optionally, in one embodiment of the present invention, as shown in FIG. 4 , step S20 controls the turn-on and turn-off of the first bidirectional switch unit and the second bidirectional switch unit, so as to transfer the grid AC input from the external charging port to The step of converting the signal into the first AC signal may include:

Step S21, controlling the conduction of the first bidirectional switch unit, so that the current flows to the transformer through the first bidirectional switch unit, and controlling the conduction of the second bidirectional switch unit, so that the current flows to the transformer through the second bidirectional switch unit, so that the inductor unit store energy.

Wherein, when the voltage of the grid AC signal is a positive voltage, the current direction of the charging and discharging device in step 21 is as shown in FIG. 3 .

Step S22, control the first bidirectional switch unit to turn on, and control the second bidirectional switch unit to turn off, so that the current flows to the first bidirectional switch unit through the inductance unit, so that the inductance unit releases the stored energy, and the energy is passed through the transformer, rectified and reversed Transformation module is transmitted to the power battery.

Wherein, when the voltage of the grid AC signal is a positive voltage, the current direction of the charging and discharging device in step 22 is as shown in FIG. 5 . In FIG. 5 , the MOS transistor Q6 and the MOS transistor Q7 in the rectification and inverter module 3 are controlled to be turned on, and the MOS transistor Q5 and the MOS transistor Q8 are controlled to be turned off.

Step S23, controlling the conduction of the first bidirectional switch unit, so that the current flows to the transformer through the first bidirectional switch unit, and controlling the conduction of the second bidirectional switch unit, so that the current flows to the transformer through the second bidirectional switch unit, so that the inductor unit store energy.

Wherein, when the voltage of the grid AC signal is a positive voltage, the current direction of the charging and discharging device in step 23 is as shown in FIG. 3 .

Step S24, control the first bidirectional switch unit to turn off, and control the second bidirectional switch unit to turn on, so that the current flows to the second bidirectional switch unit through the inductance unit, so that the inductance unit releases the stored energy, and the energy is passed through the transformer, rectified and reversed. Transformation module is transmitted to the power battery.

Wherein, the current direction of the charging and discharging device in step 24 is shown in FIG. 6 . In FIG. 6 , the MOS transistor Q6 and MOS transistor Q7 in the rectification and inverter module 3 are controlled to be turned off, and the MOS transistor Q5 and MOS transistor Q8 are controlled to be turned on.

Through steps S21 to S24, the grid AC signal input from the external charging port can be converted into a first AC signal.

Optionally, in the case of inputting the grid AC signal from the external charging port, step S20 may be based on the voltage of the grid AC signal, the current of the grid AC signal, the voltage of the power battery, the first bidirectional switch unit and the second bidirectional switch unit. The switching frequency determines the conduction time of the first bidirectional switch unit and the second bidirectional switch unit. Wherein, if the cycle corresponding to the switching frequency of the first bidirectional switch unit and the second bidirectional switch unit is T, then T=T1+T2=T3+T4, T1 is the time when the first bidirectional switch unit is turned on or the second bidirectional switch unit in step 21 The time when the two bidirectional switch units are turned on, T2 is the time when the first bidirectional switch unit is turned on or the time when the second bidirectional switch unit is turned off in step 22, and T3 is the time when the first bidirectional switch unit is turned on or the second bidirectional switch unit is turned on in step 23 The time when the two bidirectional switch units are turned on, T4 is the time when the first bidirectional switch unit is turned off or the time when the second bidirectional switch unit is turned on in step 24 .

Optionally, as shown in FIG. 1, after the step of determining whether the first instruction is a charging instruction or a discharging instruction in step S10, it may further include:

Step S30, when the first command is a discharge command, control the on and off of the rectification and inverter module to convert the DC signal output by the power battery into a first AC signal, and control the first bidirectional switch unit and the second The two bidirectional switch units are turned on and off, so as to convert the first AC signal into a grid AC signal, and output it to the grid or load through the external charging port.

Optionally, as shown in FIG. 4, step S30 controls the turn-on and turn-off of the first bidirectional switch unit and the second bidirectional switch unit, so as to convert the first AC signal into a grid AC signal and output it to the Grid or load steps can include:

Step S31 , controlling the first bidirectional switch unit to be turned on, and controlling the second bidirectional switch unit to be turned off, so that current flows through the inductor unit to the first bidirectional switch unit, so that the inductor unit stores energy.

Among them, when the AC signal of the grid is output to the load through the external charging port and the required voltage of the load is a negative voltage, or when the AC signal of the grid is output to the grid through the external charging port and the AC signal of the grid is a positive voltage, the step The current direction of the charging and discharging device in 31 is shown in FIG. 7 . In FIG. 7 , the MOS transistor Q6 and MOS transistor Q7 in the rectification and inverter module 3 are controlled to be turned off, and the MOS transistor Q5 and MOS transistor Q8 are controlled to be turned on.

Step S32, control the conduction of the first bidirectional switch unit, so that the current flows to the transformer through the first bidirectional switch unit, and control the conduction of the second bidirectional switch unit, so that the current flows to the transformer through the second bidirectional switch unit, so that the inductance unit Release the stored energy and output the energy to the grid or load.

Among them, when the AC signal of the grid is output to the load through the external charging port and the required voltage of the load is a negative voltage, or when the AC signal of the grid is output to the grid through the external charging port and the AC signal of the grid is a positive voltage, the step The current direction of the charging and discharging device in 32 is shown in FIG. 3 .

Step S33 , controlling the first bidirectional switch unit to be turned off, and controlling the second bidirectional switch unit to be turned on, so that current flows through the inductor unit to the second bidirectional switch unit, so that the inductor unit stores energy.

Among them, when the AC signal of the grid is output to the load through the external charging port and the required voltage of the load is a negative voltage, or when the AC signal of the grid is output to the grid through the external charging port and the AC signal of the grid is a positive voltage, the step The current direction of the charging and discharging device in 33 is shown in FIG. 8 . In FIG. 8 , the MOS transistor Q6 and the MOS transistor Q7 in the rectification and inverter module 3 are controlled to be turned on, and the MOS transistor Q5 and the MOS transistor Q8 are controlled to be turned off.

Step S34, controlling the conduction of the first bidirectional switch unit, so that the current flows to the transformer through the first bidirectional switch unit, and controlling the conduction of the second bidirectional switch unit, so that the current flows to the transformer through the second bidirectional switch unit, so that the inductor unit Release the stored energy and output the energy to the grid or load.

Among them, when the AC signal of the grid is output to the load through the external charging port and the required voltage of the load is a negative voltage, or when the AC signal of the grid is output to the grid through the external charging port and the AC signal of the grid is a positive voltage, the step The current direction of the charging and discharging device in 34 is shown in FIG. 3 .

Through steps S31 to S34, the grid AC signal can be output to the grid or the load through the external charging port.

Optionally, in the case of outputting the grid AC signal to the grid through the external charging port, step 30 can be based on the voltage of the grid AC signal, the current of the grid AC signal, the voltage of the power battery, the first bidirectional switch unit and the second bidirectional switch unit. The switching frequency of the switch unit determines the conduction time of the first bidirectional switch unit and the second bidirectional switch unit, and in the case of outputting the grid AC signal to the load through the external charging port, step 30 can be based on the voltage of the power battery and the load. The required voltage, the required current of the load, and the switching frequencies of the first bidirectional switch unit and the second bidirectional switch unit determine the conduction time of the first bidirectional switch unit and the second bidirectional switch unit.

Wherein, if the period corresponding to the switching frequency of the first bidirectional switch unit and the second bidirectional switch unit is T, then T=T5+T6=T7+T8, and T5 is the time when the first bidirectional switch unit is turned on or the second bidirectional switch unit is turned on in step 31. The time when the two bidirectional switch units are turned off, T6 is the time when the first bidirectional switch unit is turned on or the time when the second bidirectional switch unit is turned on in step 32, and T7 is the time when the first bidirectional switch unit is turned off or the second is turned off in step 33 The conduction time of the two bidirectional switch units, T8 is the conduction time of the first bidirectional switch unit or the conduction time of the second bidirectional switch unit in step 34 .

Optionally, as shown in FIG. 9 , the first bidirectional switch unit may include a first switch transistor with a body diode and a second switch transistor with a body diode, the first switch transistor and the second switch transistor are connected in series, and the first switch transistor The conduction direction of the body diode of the tube is opposite to the conduction direction of the body diode of the second switch tube; the second bidirectional switch unit may include a third switch tube with a body diode and a fourth switch tube with a body diode, the third switch The tube and the fourth switch tube are connected in series, and the conduction direction of the body diode of the third switch tube is opposite to that of the body diode of the fourth switch tube. In this way, the first bidirectional switch unit 11 only needs to be composed of the first switch tube and the second switch tube, and the structure of the first bidirectional switch unit 11 is simple and requires few components; the second bidirectional switch unit 12 only needs to be composed of the third The switch tube and the fourth switch tube are formed, and the structure of the second bidirectional switch unit 12 is simple and requires few components. Optionally, as shown in FIG. 3, the first switch tube may be the first MOS tube Q1, the second switch tube may be the second MOS tube Q2, the third switch tube may be the third MOS tube Q3, and the fourth switch tube It may be the fourth MOS transistor Q4.

Since the first bidirectional switch unit 11 in the embodiment of the present invention only needs to be composed of a first bidirectional switch device, or only needs to be composed of a first switch tube and a second switch tube; the second bidirectional switch unit 12 only needs to be composed of a second bidirectional switch components, or only need to be composed of a third switch tube and a fourth switch tube, therefore, the structure of the power factor correction module 1 is simpler than that of the power factor correction circuit structure of the car charger in the related art, and the required components The control method of the charging and discharging device in the embodiment of the present invention is simpler for the control scheme of the power factor correction module 1, which is beneficial to reduce the control cost and improve the control efficiency.

Optionally, as shown in FIG. 9, in one embodiment of the present invention, the conduction direction of the body diode of the first switch tube and the conduction direction of the body diode of the third switch tube may face the transformer, as shown in FIG. 10 As shown, step S20 controls the turn-on and turn-off of the first bidirectional switch unit and the second bidirectional switch unit, so that the step of converting the grid AC signal input from the external charging port into the first AC signal may include:

Step S25 , controlling the second switch tube and the fourth switch tube to be turned on, and controlling the first switch tube and the third switch tube to be turned off, so that the inductance unit stores energy.

Wherein, when the voltage of the grid AC signal is a positive voltage, the current direction of the charging and discharging device in step 25 is the same as the current direction in FIG. 3 .

Step S26, controlling the first switching tube, the third switching tube, and the fourth switching tube to be turned off, and controlling the second switching tube to be turned on, so that the inductance unit releases the stored energy, and the energy is transmitted to the power supply through the transformer and the rectification and inverter module Battery.

Wherein, when the voltage of the grid AC signal is a positive voltage, the current direction of the charging and discharging device in step 26 is the same as the current direction in FIG. 5 .

Step S27 , controlling the first switch tube and the third switch tube to be turned off, and controlling the second switch tube and the fourth switch tube to be turned on, so that the inductance unit stores energy.

Wherein, when the voltage of the grid AC signal is a positive voltage, the current direction of the charging and discharging device in step 27 is the same as that in FIG. 3 .

Step S28, controlling the fourth switching tube to be turned on, and controlling the first switching tube, the second switching tube and the third switching tube to be turned off, so that the inductance unit releases the stored energy, and the energy is transmitted to the power supply through the transformer and the rectification and inverter module Battery.

Wherein, when the voltage of the grid AC signal is a positive voltage, the current direction of the charging and discharging device in step 28 is the same as the current direction in FIG. 6 .

At this time, in the case of inputting the grid AC signal from the external charging port, step S20 can be based on the voltage of the grid AC signal, the current of the grid AC signal, the voltage of the power battery, the switch of the first bidirectional switch unit and the switch of the second bidirectional switch unit The frequency determines the conduction time of the first switch tube and the second switch tube in the first bidirectional switch unit, and the conduction time of the third switch tube and the fourth switch tube in the second bidirectional switch unit.

Optionally, as shown in FIG. 9, in one embodiment of the present invention, the conduction direction of the body diode of the first switch tube and the conduction direction of the body diode of the third switch tube may face the transformer, as shown in FIG. 10 As shown, the step S30 controls the turn-on and turn-off of the first bidirectional switch unit and the second bidirectional switch unit, so as to convert the first AC signal into a grid AC signal, and output the step to the grid or load through the external charging port, which may include :

Step S35 , controlling the second switch to be turned on, and controlling the first switch, the third switch, and the fourth switch to be turned off, so that the inductor unit stores energy.

Wherein, when the AC signal of the power grid is output to the load through the external charging port and the required voltage of the load is a negative voltage, the current direction of the charging and discharging device in step 35 is the same as that in FIG. 7 .

Step S36, controlling the second switch tube and the fourth switch tube to be turned on, and controlling the first switch tube and the third switch tube to be turned off, so that the inductance unit releases the stored energy, and the energy is output to the grid or the load.

Wherein, in the case that the grid AC signal is output to the load through the external charging port and the required voltage of the load is a negative voltage, the current direction of the charging and discharging device in step 36 is the same as that in FIG. 3 .

Step S37 , controlling the first switch tube, the second switch tube, and the third switch tube to be turned off, and the fourth switch tube to be turned on, so that the inductance unit stores energy.

Wherein, in the case that the grid AC signal is output to the load through the external charging port and the required voltage of the load is a negative voltage, the current direction of the charging and discharging device in step 37 is the same as that in FIG. 8 .

Step S38 , controlling the second switch tube and the fourth switch tube to be turned on, and controlling the first switch tube and the third switch tube to be turned off, so that the inductance unit releases the stored energy, and the energy is output to the grid or the load.

Wherein, in the case that the grid AC signal is output to the load through the external charging port and the required voltage of the load is a negative voltage, the current direction of the charging and discharging device in step 38 is the same as that in FIG. 3 .

At this time, in the case of outputting the AC signal of the grid to the grid through the external charging port, step 30 may be based on the voltage of the AC signal of the grid, the current of the AC signal of the grid, the voltage of the power battery, the first bidirectional switch unit and the second bidirectional switch The switching frequency of the unit determines the conduction time of the first switch tube and the second switch tube in the first bidirectional switch unit, the third switch tube and the fourth switch tube in the second bidirectional switch unit, and the grid AC output through the external charging port. In the case of the signal to the load, step 30 can determine the first bidirectional switch unit in the first bidirectional switch unit according to the voltage of the power battery, the required voltage of the load, the required current of the load, the switching frequency of the first bidirectional switch unit and the second bidirectional switch unit. The conduction time of the first switch tube and the second switch tube, and the third switch tube and the fourth switch tube in the second bidirectional switch unit.

The control method of the charging and discharging device according to the embodiment of the present invention has the following advantages:

Since the power factor correction module in the charging and discharging device includes a first bidirectional switch unit and a second bidirectional switching unit, the control method of the charging and discharging device in the embodiment of the present invention controls the first bidirectional switching unit when the first instruction is a charging instruction. The switch unit and the second bidirectional switch unit are turned on and off to convert the grid AC signal input from the external charging port into the first AC signal, which can not only realize the power factor correction function of the power factor correction module, but also ensure the current The direction of the current passing through the first bidirectional switch unit and the second bidirectional switch unit is consistent with the conduction direction, that is, the current direction of the power factor correction module is controlled, and the control reliability of the power factor correction module is high.

In addition, since the transformer in the charging and discharging device is arranged between the power factor correction module and the rectification and inverter module, the transformer can also be arranged between the power factor correction module and the rectification module. Compared with the charging circuit in the related art, the present invention implements In the example, the charging and discharging device can realize the function integration of the on-board DC converter and the on-board charger in one circuit (that is, the power factor correction module, the rectification and inverter module for charging or discharging the power battery 30, and the The rectification module used to charge the battery is integrated in one circuit), and at least the rectification topology corresponding to the primary coil of the transformer can be reduced, and the rectification module only needs one rectification topology, and the first bidirectional switch unit only needs to be composed of the first bidirectional switch device, or only need to be composed of the first switch tube and the second switch tube, the second bidirectional switch unit only needs to be composed of the second bidirectional switch device, or only need to be composed of the third switch tube and the fourth switch tube, effectively The circuit structure is simplified and the number of components is reduced. Therefore, the control method of the charging and discharging device in the embodiment of the present invention only needs to control the first bidirectional switching unit, the second bidirectional switching unit, the rectifying and inverter module and the rectifying module in the charging and discharging device with a simplified structure, and the control scheme is simpler , to reduce control costs and improve control efficiency.

It should be noted that, for the method embodiment, for the sake of simple description, it is expressed as a series of action combinations, but those skilled in the art should know that the embodiment of the present invention is not limited by the described action sequence, because According to the embodiment of the present invention, certain steps may be performed in other orders or simultaneously. Secondly, those skilled in the art should also know that the embodiments described in the specification belong to preferred embodiments, and the actions involved are not necessarily required by the embodiments of the present invention.

The embodiment of the present invention also discloses a charging and discharging device, which includes a controller, a power factor correction module connected in sequence, a transformer, and a rectification and inverter module. The controller is used to control the power factor correction module and the rectification and inverter module to realize the above-mentioned A method for controlling a charging and discharging device.

The charging and discharging device of the embodiment of the present invention has the following advantages:

Since the power factor correction module in the charging and discharging device includes a first bidirectional switch unit and a second bidirectional switching unit, the control method of the charging and discharging device in the embodiment of the present invention controls the first bidirectional switching unit when the first instruction is a charging instruction. The switch unit and the second bidirectional switch unit are turned on and off to convert the grid AC signal input from the external charging port into the first AC signal, which can not only realize the power factor correction function of the power factor correction module, but also ensure the current The direction of the current passing through the first bidirectional switch unit and the second bidirectional switch unit is consistent with the conduction direction, that is, the current direction of the power factor correction module is controlled, and the control reliability of the power factor correction module is high.

In addition, since the transformer in the charging and discharging device is arranged between the power factor correction module and the rectification and inverter module, the transformer can also be arranged between the power factor correction module and the rectification module. Compared with the charging circuit in the related art, the present invention implements In the example, the charging and discharging device can realize the function integration of the on-board DC converter and the on-board charger in one circuit (that is, the power factor correction module, the rectification and inverter module for charging or discharging the power battery 30, and the The rectification module used to charge the battery is integrated in one circuit), and at least the rectification topology corresponding to the primary coil of the transformer can be reduced, and the rectification module only needs one rectification topology, and the first bidirectional switch unit only needs to be composed of the first bidirectional switch device, or only need to be composed of the first switch tube and the second switch tube, the second bidirectional switch unit only needs to be composed of the second bidirectional switch device, or only need to be composed of the third switch tube and the fourth switch tube, effectively The circuit structure is simplified and the number of components is reduced. Therefore, the control method of the charging and discharging device in the embodiment of the present invention only needs to control the first bidirectional switching unit, the second bidirectional switching unit, the rectifying and inverter module and the rectifying module in the charging and discharging device with a simplified structure, and the control scheme is simpler , to reduce control costs and improve control efficiency.

As for the embodiment of the charging and discharging device, since it includes a controller for realizing the above-mentioned control method of the charging and discharging device, the description is relatively simple, and for related parts, please refer to the part of the description of the controlling method embodiment.

The embodiment of the present invention also discloses an electric vehicle, including the above charging and discharging device.

The electric vehicle in the embodiment of the present invention may include a power battery and a storage battery, wherein the power battery is connected to the rectification and inverter module in the charge and discharge device, and the battery is connected to the rectification module in the charge and discharge device.

The electric vehicle of the embodiment of the present invention includes the following advantages:

Since the power factor correction module in the charging and discharging device includes a first bidirectional switch unit and a second bidirectional switching unit, the control method of the charging and discharging device in the embodiment of the present invention controls the first bidirectional switching unit when the first instruction is a charging instruction. The switch unit and the second bidirectional switch unit are turned on and off to convert the grid AC signal input from the external charging port into the first AC signal, which can not only realize the power factor correction function of the power factor correction module, but also ensure the current The direction of the current passing through the first bidirectional switch unit and the second bidirectional switch unit is consistent with the conduction direction, that is, the current direction of the power factor correction module is controlled, and the control reliability of the power factor correction module is high.

In addition, since the transformer in the charging and discharging device is arranged between the power factor correction module and the rectification and inverter module, the transformer can also be arranged between the power factor correction module and the rectification module. Compared with the charging circuit in the related art, the present invention implements In the example, the charging and discharging device can realize the function integration of the on-board DC converter and the on-board charger in one circuit (that is, the power factor correction module, the rectification and inverter module for charging or discharging the power battery 30, and the The rectification module used to charge the battery is integrated in one circuit), and at least the rectification topology corresponding to the primary coil of the transformer can be reduced, and the rectification module only needs one rectification topology, and the first bidirectional switch unit only needs to be composed of the first bidirectional switch device, or only need to be composed of the first switch tube and the second switch tube, the second bidirectional switch unit only needs to be composed of the second bidirectional switch device, or only need to be composed of the third switch tube and the fourth switch tube, effectively The circuit structure is simplified and the number of components is reduced. Therefore, the control method of the charging and discharging device in the embodiment of the present invention only needs to control the first bidirectional switching unit, the second bidirectional switching unit, the rectifying and inverter module and the rectifying module in the charging and discharging device with a simplified structure, and the control scheme is simpler , to reduce control costs and improve control efficiency.

For the embodiment of the electric vehicle, because it includes the above-mentioned charging and discharging device, the description is relatively simple, and relevant parts can be referred to part of the description of the embodiment of the charging and discharging device.

Each embodiment in this specification is described in a progressive manner, each embodiment focuses on the difference from other embodiments, and the same and similar parts of each embodiment can be referred to each other.

Those skilled in the art should understand that the embodiments of the present invention may be provided as methods, devices, or computer program products. Accordingly, embodiments of the invention may take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, embodiments of the invention may take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) having computer-usable program code embodied therein.

Embodiments of the present invention are described with reference to flowcharts and/or block diagrams of methods, terminal devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each procedure and/or block in the flowchart and/or block diagram, and a combination of procedures and/or blocks in the flowchart and/or block diagram can be realized by computer program instructions. These computer program instructions may be provided to a general purpose computer, special purpose computer, embedded processor or processor of other programmable data processing terminal equipment to produce a machine such that instructions executed by the computer or processor of other programmable data processing terminal equipment Produce means for realizing the functions specified in one or more procedures of the flowchart and/or one or more blocks of the block diagram.

These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing terminal to operate in a specific manner, such that the instructions stored in the computer-readable memory produce an article of manufacture comprising instruction means, the The instruction means implements the functions specified in one or more procedures of the flowchart and/or one or more blocks of the block diagram.

These computer program instructions can also be loaded into a computer or other programmable data processing terminal equipment, so that a series of operational steps are performed on the computer or other programmable terminal equipment to produce computer-implemented processing, thereby The instructions executed above provide steps for implementing the functions specified in one or more procedures of the flowchart and/or one or more blocks of the block diagram.

Having described preferred embodiments of embodiments of the present invention, additional changes and modifications to these embodiments can be made by those skilled in the art once the basic inventive concept is appreciated. Therefore, the appended claims are intended to be interpreted to cover the preferred embodiment and all changes and modifications which fall within the scope of the embodiments of the present invention.

Finally, it should also be noted that in this text, relational terms such as first and second etc. are only used to distinguish one entity or operation from another, and do not necessarily require or imply that these entities or operations, any such actual relationship or order exists. Furthermore, the term "comprises", "comprises" or any other variation thereof is intended to cover a non-exclusive inclusion such that a process, method, article, or terminal equipment comprising a set of elements includes not only those elements, but also includes elements not expressly listed. other elements identified, or also include elements inherent in such a process, method, article, or terminal equipment. Without further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of additional identical elements in the process, method, article or terminal device comprising said element.

The control method of a charging and discharging device, a charging and discharging device and an electric vehicle provided by the present invention have been introduced in detail above. In this paper, specific examples are used to illustrate the principle and implementation of the present invention. The above The description of the embodiment is only used to help understand the method of the present invention and its core idea; at the same time, for those of ordinary skill in the art, according to the idea of the present invention, there will be changes in the specific implementation and scope of application. As mentioned above, the contents of this specification should not be construed as limiting the present invention.

Claims (11)

1. A control method for a charging and discharging device, characterized in that the charging and discharging device includes a sequentially connected power factor correction module, a transformer, and a rectification and inverter module for charging or discharging a power battery, and the transformer includes a first A winding, a second winding and a third winding, the first winding and the second winding are connected in series, the power factor correction module includes a first bidirectional switch unit, a second bidirectional switch unit and an inductance unit, the first The first end of a bidirectional switch unit is connected to the first end of the first winding connected in series with the second winding, and the first end of the second bidirectional switch unit is connected to the first winding and the second winding. The second end of the winding in series is connected, the second end of the first bidirectional switch unit and the second end of the second bidirectional switch unit are connected to the first end of the inductance unit, and the second end of the inductance unit end is connected to the first end of the external charging port, the midpoint of the series connection between the first winding and the second winding is connected to the second end of the external charging port, and the rectification and inverter module is connected to the third winding connection; the control method includes: When receiving the first instruction, judging whether the first instruction is a charging instruction or a discharging instruction; When the first instruction is the charging instruction, the first bidirectional switch unit and the second bidirectional switch unit are controlled to be turned on and off, so as to exchange the power grid input from the external charging port Convert the signal into a first AC signal, and control the on and off of the rectification and inverter module, so as to convert the first AC signal into a DC signal, and charge the power battery through the DC signal, wherein , the voltage corresponding to the first AC signal is higher than the voltage corresponding to the grid AC signal; The charging and discharging device also includes a battery, and a rectification module for charging the battery; the transformer also includes a fourth winding, and the rectification module is connected to the fourth winding; the first winding, the second The winding and the fourth winding are located on the same side of the transformer. 2. The control method according to claim 1, characterized in that, the control of turning on and off of the first bidirectional switch unit and the second bidirectional switch unit, so as to input from the external charging port The step of converting the grid AC signal into the first AC signal includes: controlling the conduction of the first bidirectional switch unit, so that the current flows to the transformer through the first bidirectional switch unit, and controlling the conduction of the second bidirectional switch unit, so that the current flows through the second bidirectional switch unit flow to the transformer so that the inductance unit stores energy; controlling the first bidirectional switch unit to be turned on, and controlling the second bidirectional switch unit to be turned off, so that current flows to the first bidirectional switch unit through the inductance unit, so that the inductance unit releases stored energy , the energy is transmitted to the power battery through the transformer and the rectification and inverter module; controlling the conduction of the first bidirectional switch unit, so that the current flows to the transformer through the first bidirectional switch unit, and controlling the conduction of the second bidirectional switch unit, so that the current flows through the second bidirectional switch unit flow to the transformer so that the inductance unit stores energy; controlling the first bidirectional switch unit to be turned off, and controlling the second bidirectional switch unit to be turned on, so that current flows to the second bidirectional switch unit through the inductance unit, so that the inductance unit releases stored energy , the energy is transmitted to the power battery through the transformer and the rectification and inverter module. 3. The control method according to claim 1, further comprising: after the step of judging whether the first instruction is a charging instruction or a discharging instruction: When the first command is the discharge command, control the on and off of the rectification and inverter module to convert the DC signal output by the power battery into the first AC signal, and control Turning on and off the first bidirectional switch unit and the second bidirectional switch unit to convert the first AC signal into the grid AC signal and output it to the grid through the external charging port or load. 4. The control method according to claim 3, wherein the control of turning on and off of the first bidirectional switch unit and the second bidirectional switch unit is used to convert the first AC signal The step of generating an AC signal for the power grid and outputting it to the power grid or load through the external charging port includes: controlling the first bidirectional switch unit to be turned on, and controlling the second bidirectional switch unit to be turned off, so that current flows to the first bidirectional switch unit through the inductance unit, so that the inductance unit stores energy; controlling the conduction of the first bidirectional switch unit, so that the current flows to the transformer through the first bidirectional switch unit, and controlling the conduction of the second bidirectional switch unit, so that the current flows through the second bidirectional switch unit flow to the transformer, so that the inductance unit releases the stored energy, and the energy is output to the grid or the load; controlling the first bidirectional switch unit to be turned off, and controlling the second bidirectional switch unit to be turned on, so that current flows to the second bidirectional switch unit through the inductance unit, so that the inductance unit stores energy; controlling the conduction of the first bidirectional switch unit, so that the current flows to the transformer through the first bidirectional switch unit, and controlling the conduction of the second bidirectional switch unit, so that the current flows through the second bidirectional switch unit flow to the transformer, so that the inductance unit releases the stored energy, and the energy is output to the grid or the load. 5. The control method according to claim 3, characterized in that, The first bidirectional switch unit includes a first switch tube with a body diode and a second switch tube with a body diode, the first switch tube and the second switch tube are connected in series, and the body of the first switch tube The conduction direction of the diode is opposite to the conduction direction of the body diode of the second switch tube; The second bidirectional switch unit includes a third switch tube with a body diode and a fourth switch tube with a body diode, the third switch tube and the fourth switch tube are connected in series, and the body of the third switch tube The conduction direction of the diode is opposite to the conduction direction of the body diode of the fourth switch transistor. 6. The control method according to claim 5, wherein the conduction direction of the body diode of the first switch tube and the conduction direction of the body diode of the third switch tube face the transformer, and the The step of controlling the turn-on and turn-off of the first bidirectional switch unit and the second bidirectional switch unit so as to convert the grid AC signal input from the external charging port into a first AC signal includes: controlling the second switch tube and the fourth switch tube to be turned on, and controlling the first switch tube and the third switch tube to be turned off, so that the inductance unit stores energy; controlling the first switch tube, the third switch tube, and the fourth switch tube to be turned off, and controlling the second switch tube to be turned on, so that the inductance unit releases stored energy, and the energy is passed through The transformer and the rectification and inverter module are transmitted to the power battery; controlling the first switch tube and the third switch tube to be turned off, and controlling the second switch tube and the fourth switch tube to be turned on, so that the inductance unit stores energy; controlling the fourth switching tube to be turned on, and controlling the first switching tube, the second switching tube, and the third switching tube to be turned off, so that the inductance unit releases stored energy, and the energy is passed through The transformer and the rectification and inverter module are transmitted to the power battery. 7. The control method according to claim 5, wherein the control of turning on and off of the first bidirectional switch unit and the second bidirectional switch unit is used to convert the first AC signal The step of generating an AC signal for the power grid and outputting it to the power grid or load through the external charging port includes: controlling the second switching tube to be turned on, and controlling the first switching tube, the third switching tube and the fourth switching tube to be turned off, so that the inductance unit stores energy; controlling the second switch tube and the fourth switch tube to be turned on, and controlling the first switch tube and the third switch tube to be turned off, so that the inductance unit releases the stored energy, and the energy output to said grid or said load; controlling the first switch tube, the second switch tube, and the third switch tube to be turned off, and the fourth switch tube to be turned on, so that the inductance unit stores energy; controlling the second switch tube and the fourth switch tube to be turned on, and controlling the first switch tube and the third switch tube to be turned off, so that the inductance unit releases the stored energy, and the energy output to the grid or the load. 8. The control method according to claim 1, characterized in that, When the grid AC signal is input from the external charging port, according to the voltage of the grid AC signal, the current of the grid AC signal, the voltage of the power battery, the first bidirectional switch unit and the second bidirectional The switching frequency of the switch unit determines the conduction time of the first bidirectional switch unit and the second bidirectional switch unit. 9. The control method according to claim 3, characterized in that, When the grid AC signal is output to the grid through the external charging port, according to the voltage of the grid AC signal, the current of the grid AC signal, the voltage of the power battery, the first bidirectional switch unit and the The switching frequency of the second bidirectional switch unit determines the conduction time of the first bidirectional switch unit and the second bidirectional switch unit; In the case of outputting the grid AC signal to the load through the external charging port, according to the voltage of the power battery, the required voltage of the load, the required current of the load, the first bidirectional The switching frequency of the switch unit and the second bidirectional switch unit determines the conduction time of the first bidirectional switch unit and the second bidirectional switch unit. 10. A charging and discharging device, characterized in that it includes a controller, a sequentially connected power factor correction module, a transformer, and a rectification and inverter module, and the controller is used to control the power factor correction module and the rectification and inverter module , so as to realize the control method of the charging and discharging device described in any one of claims 1 to 9. 11. An electric vehicle, characterized by comprising the charging and discharging device according to claim 10.

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