CN211893100U - High Voltage Circuits for Electric Vehicles - Google Patents

Abstract

The application discloses a high-voltage circuit for an electric vehicle, including a high-voltage power supply, a precharge controllable switch, a discharge controllable switch, a multi-function resistor and a high-voltage electrical module; The electrical modules are connected in series to form the pre-charging circuit of the high-voltage circuit of the electric vehicle; the discharge controllable switch, the multi-function resistor and the high-voltage electrical module are connected in series to form the discharge circuit of the high-voltage circuit of the electric vehicle; the high-voltage electrical module includes a high-voltage capacitor; When the discharge controllable switch is disconnected and the precharge controllable switch is closed, the precharge circuit is connected to enable the high voltage power supply to precharge the high voltage capacitor through the multi-function resistor; when the precharge controllable switch is disconnected, the discharge controllable switch is closed When , the discharge circuit is connected to discharge the high-voltage capacitor through the multi-function resistor. The high-voltage circuit of the present application solves the problems in the prior art that the pre-charging resistor and the discharging resistor are set separately, which is large in size and high in cost.

Description

High Voltage Circuits for Electric Vehicles

technical field

The present application relates to the technical field of electronic circuits, and in particular, to a high-voltage circuit of an electric vehicle.

Background technique

In the field of new energy vehicles, high-voltage electrical appliances have high-voltage capacitors. When supplying power to high-voltage electrical appliances, the high-voltage capacitors need to be charged first, so as to avoid high-voltage electrical appliances from being directly impacted by large currents. . That is, a pre-charging circuit needs to be designed to charge the high-voltage capacitor. The principle of charging the high-voltage capacitor by the pre-charging circuit is to add a pre-charging resistor and a pre-charging relay to the pre-charging circuit to control the charging current of the high-voltage capacitor.

After the electric vehicle is powered off, a large amount of charge is stored on the high-voltage capacitor, which is very dangerous to the high-voltage electrical appliances and operators. Therefore, the high-voltage capacitor needs to be discharged first. That is, a discharge circuit needs to be designed to discharge the high-voltage capacitor. The principle of discharging the high-voltage capacitor in the discharge circuit is to add a discharge resistor to the discharge circuit to discharge. The existing precharge resistance and discharge resistance are set separately, which is bulky and expensive.

Utility model content

The present application provides a high-voltage circuit for an electric vehicle, so as to solve the problems in the prior art that the pre-charging resistance and the discharging resistance are set separately, the volume is large, and the cost is high.

The application provides a high-voltage circuit of an electric vehicle, the high-voltage circuit of the electric vehicle includes a high-voltage power supply, a precharge controllable switch, a discharge controllable switch, a multi-function resistor and a high-voltage electrical module;

the high-voltage power supply, the pre-charge controllable switch, the multi-function resistor and the high-voltage electrical appliance module are connected in series to form a pre-charge circuit of the high-voltage circuit of the electric vehicle;

The discharge controllable switch, the multifunctional resistor and the high-voltage electrical appliance module are connected in series to form a discharge loop of the high-voltage circuit of the electric vehicle;

The high-voltage electrical module includes a high-voltage capacitor;

When the discharge controllable switch is turned off and the precharge controllable switch is turned on, the precharge circuit is connected, so that the high voltage power supply precharges the high voltage capacitor through the multifunctional resistor;

When the precharge controllable switch is turned off and the discharge controllable switch is turned on, the discharge circuit is connected to discharge the high-voltage capacitor through the multifunctional resistor.

In an embodiment, the high-voltage circuit of the electric vehicle further includes a main controllable switch, and the high-voltage power supply, the main controllable switch and the high-voltage electrical module are connected in series to form the main controllable switch of the high-voltage circuit of the electric vehicle. charging circuit;

When the precharge controllable switch and the discharge controllable switch are disconnected, and the main controllable switch is closed, the main charging circuit is connected to allow the high-voltage power supply to charge the high-voltage electrical module.

In one embodiment, the high-voltage circuit of the electric vehicle further includes a battery management system, the battery management system is connected to the pre-charging circuit, the main charging circuit and the discharging circuit, and the battery management system is used to control The connection of the pre-charging circuit, the main charging circuit and the discharging circuit is on and off.

In one embodiment, the battery management system includes a voltage detection unit for detecting the voltage of the high-voltage capacitor to generate a voltage detection value.

In an embodiment, the high-voltage circuit of the electric vehicle further includes a control unit, the control unit is connected to the voltage detection unit, and the control unit is used to control the precharge controllable switch and the main controllable switch and the opening and closing of the discharge controllable switch.

In one embodiment, the control unit can determine whether the voltage detection value is greater than a preset precharge voltage threshold, and when the voltage detection value is greater than the preset precharge voltage threshold, by controlling the precharge voltage The control switch is open and the main control switch is closed so that the pre-charging circuit is open and the main charging circuit is connected.

In one embodiment, the control unit can determine whether the detected voltage value is less than a preset safe voltage threshold, and when the detected voltage value is less than the preset safe voltage threshold, by controlling the discharge controllable switch to turn off open to disconnect the discharge circuit.

In one embodiment, the preset safety voltage threshold is 36V or 60V.

In one embodiment, the high-voltage electrical appliance module includes a plurality of sub-modules, the plurality of sub-modules are connected in parallel with each other, and each of the sub-modules includes one of the high-voltage capacitors.

In one embodiment, the discharge controllable switch is a relay, an IGBT or a MOSFET.

The high-voltage circuit of the electric vehicle of the present application integrates the function of the pre-charge resistor and the function of the discharge resistor into the multi-function resistor, which can simplify the function that originally required two resistors to be completed by using the same resistor. The function of the multi-function resistor is integrated, which is easy to install and maintain, and the associated damage in the event of failure is small, which makes the circuit function definition of the high-voltage circuit of the electric vehicle clearer, which is beneficial to the function integration of the vehicle circuit; on the other hand, it saves a large amount of damage. The cost and installation space of the power resistor and its control circuit improve the power density and bulk density of the high-voltage circuit of the electric vehicle, with strong economic benefits, high flexibility and wide application range.

Description of drawings

In order to illustrate the technical solutions of the present invention more clearly, the following briefly introduces the accompanying drawings used in the implementation manner. Obviously, the accompanying drawings in the following description are only some implementations of the present utility model. For those of ordinary skill in the art, other drawings can also be obtained from these drawings without any creative effort.

1 is a circuit diagram of a high-voltage circuit of an electric vehicle in the prior art;

FIG. 2 is a circuit diagram of a high-voltage circuit of an electric vehicle provided by an embodiment of the present application.

Detailed ways

The technical solutions in the embodiments of the present utility model will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all the implementations. example. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the protection scope of the present invention.

In the field of new energy vehicles, as shown in Figure 1, high-voltage electrical appliances have a high-voltage capacitor C1. When supplying power to high-voltage electrical appliances, it is necessary to charge the high-voltage capacitor C1 first to avoid direct impact of large currents such as relays and contactors. Such as controllable switching devices and high-voltage capacitors, resulting in damage to controllable switching devices and high-voltage electrical appliances. That is, a pre-charging circuit needs to be designed to charge the high-voltage capacitor. The principle of charging the high-voltage capacitor by the pre-charging loop is to add a pre-charging resistor R' and a pre-charging relay S1' to the pre-charging loop to control the charging current of the high-voltage capacitor C1.

After the electric vehicle is powered off, a large amount of charge is stored on the high-voltage capacitor, which will bring great danger to both high-voltage electrical appliances and operators. Therefore, the high-voltage capacitor needs to be discharged first. That is, a discharge circuit needs to be designed to discharge the high-voltage capacitor. The principle of discharging the high-voltage capacitor in the discharge loop is to add a discharge resistor R1 to the discharge loop, and connect the discharge resistor R1 and the high-voltage capacitor C1 in parallel to discharge. The existing pre-charging resistor R' and the discharging resistor R1 are set separately, which are bulky and expensive.

In view of this, please refer to FIG. 2, the present application provides a high-voltage circuit of an electric vehicle, the high-voltage circuit of the electric vehicle includes a high-voltage power supply, a pre-charge controllable switch S1, a discharge controllable switch S2, a multi-function resistor R and a high-voltage electrical module 10.

The high voltage power supply, the precharge controllable switch S1, the multifunctional resistor R and the high voltage electrical appliance module 10 are connected in series to form a precharge circuit of the high voltage circuit of the electric vehicle; the discharge controllable switch S2, the multifunctional resistor R and the high voltage electrical appliance module 10 are connected in series. connected in series to form a discharge loop of a high-voltage circuit of an electric vehicle; the high-voltage electrical appliance module 10 includes a high-voltage capacitor C; when the discharge controllable switch S2 is turned off and the precharge controllable switch S1 is closed, the precharge loop is connected to allow the high-voltage power supply to pass through The multi-function resistor R pre-charges the high-voltage capacitor C; when the pre-charge controllable switch S1 is turned off and the discharge controllable switch S2 is closed, the discharge circuit is connected so that the high-voltage capacitor C is discharged through the multi-function resistor R.

It can be understood that, before the whole vehicle is powered on, only the pre-charge controllable switch S1 is closed, so that the pre-charge circuit is connected, and the current of the high-voltage power supply flows through the multi-function resistor R and flows to the high-voltage capacitor C, so that the high-voltage capacitor C can be pre-charged. Charge. As the voltage of the high-voltage capacitor C becomes larger and larger, the variation of the voltage (the voltage of the high-voltage power supply - the voltage of the high-voltage capacitor C) will become smaller and smaller, that is, the precharge current will become smaller and smaller, so that the large current can be effectively avoided. The high-voltage capacitor C and the pre-charged controllable switch S1 are directly impacted to cause damage to the high-voltage capacitor C and the pre-charged controllable switch S1. When the whole vehicle is powered on, the high-voltage capacitor C stores a large amount of charge. If it is not released in time, it will increase the risk of accidental touch by the operator and cause serious safety accidents. Therefore, after the whole vehicle is powered off, only the discharge controllable switch S2 is closed, so that the discharge circuit is connected, and the high-voltage capacitor C acts as a power source to flow through the multi-function resistor R to start discharging. As the discharge process progresses, the high-voltage capacitor C The voltage of the capacitor C will become smaller and smaller, so that the voltage of the high-voltage capacitor C can be effectively discharged to a safe voltage range that is not easy to cause accidental touch, which is beneficial to ensure the personal safety of the operator.

Therefore, the multi-function resistor R can be used as a pre-charging resistor in the pre-charging circuit, thereby increasing the resistance of the pre-charging circuit, thereby further improving the efficiency of pre-charging, so that the voltage of the high-voltage capacitor C can be rapidly increased to a level that is difficult to achieve. Within the range of safe voltages affected by large currents. In addition, the multi-function resistor R can also be used as a discharge resistor in the discharge circuit, thereby increasing the resistance of the discharge circuit, thereby further improving the discharge efficiency, so that the voltage of the high-voltage capacitor C can be quickly discharged so that it is not easy to cause accidental touch. within the safe voltage range. That is, the multifunctional resistor R has the dual function of a precharge resistor and a discharge resistor.

By integrating the functions of the precharge resistor and the discharge resistor into the multifunctional resistor R, the original function that requires two resistors can be simplified to the same resistor. On the one hand, the function of the multifunctional resistor R can be simplified. Integrated, easy to install and maintain, with little damage in the event of a fault, making the circuit function definition of the high-voltage circuit of the electric vehicle clearer, which is beneficial to the functional integration of the vehicle circuit; on the other hand, it saves a high-power resistor and its control circuit. The cost and installation space of the electric vehicle have improved the power density and bulk density of the high-voltage circuit of the electric vehicle, with strong economic benefits, high flexibility and a wide range of applications.

It should be noted that the multifunctional resistor R is a power resistor, which can not only withstand the requirements of the precharge current when the precharge circuit is connected, but also meet the requirements of the discharge power when the discharge circuit is connected. In other words, the resistance value of the multi-function resistor R needs to be designed according to the actual needs of the high-voltage circuit of the electric vehicle. For example, it can be adjusted according to the output capability of the high-voltage power supply and the output capability of the precharged controllable switch S1. Those skilled in the art can design according to the actual situation, which is not specifically limited in this application.

In addition, in the embodiments of the present application, when the multi-function resistor R is used as a discharge resistor, it is connected in series in the discharge circuit, that is, connected in series with the high-voltage capacitor C, thereby avoiding the parallel connection between the discharge resistor and the high-voltage capacitor C in the conventional design. The problem of continuous energy consumption and increased cost caused by the setting makes it difficult to maintain when problems occur, and it is easy to increase the failure rate of the high-voltage electrical appliances corresponding to the high-voltage capacitor C. When the discharge resistor has a short circuit or a serious fire failure, the associated loss is large. The problem.

It should be noted that the improvement of the multifunctional resistor R in the present application can be applied to other application scenarios. Specifically, the series arrangement of the discharge controllable switch S2 and the multi-function resistor R can be separately arranged inside the controller of the high-voltage electrical appliance with the high-voltage capacitor C, such as the motor controller, or the inside of the uninterruptible power supply, for example, and For example, in an inverter or other circuits that have large-capacity DC capacitors and require pre-charging and discharging, the control principle remains unchanged and still falls within the scope of protection of this application.

In the embodiment of the present application, the high-voltage circuit of the electric vehicle further includes a main controllable switch S3, and the high-voltage power supply, the main controllable switch S3 and the high-voltage electrical appliance module 10 are connected in series to form the main charging circuit of the high-voltage circuit of the electric vehicle; When the charging controllable switch S1 and the discharging controllable switch S2 are disconnected, and the main controllable switch S3 is closed, the main charging circuit is connected to enable the high-voltage power supply to charge the high-voltage electrical appliance module 10 .

It can be understood that the precharge controllable switch S1, the main controllable switch S3 and the discharge controllable switch S2 are connected in parallel, that is, the precharge controllable switch S1, the main controllable switch S3 and the discharge controllable switch S2 work. Not in parallel, but sequentially. In other words, when the whole vehicle is powered on, the precharge controllable switch S1 is closed, the main controllable switch S3 and the discharge controllable switch S2 are disconnected, the precharge circuit is connected, and the high voltage capacitor C is precharged. When the precharge is completed, the precharge controllable switch S1 is turned off, and the main controllable switch S3 is closed, so that the discharge controllable switch S2 remains open, so that the main charging circuit is connected, and the whole vehicle power-on process is completed. When the whole vehicle is powered off, the main controllable switch S3 is turned off, and the discharge controllable switch S2 is closed, so that the precharge controllable switch S1 remains open, so that the discharge circuit is connected, and the high-voltage capacitor C is discharged. When the discharge process is completed, the discharge controllable switch S2 is turned off, and the discharge process ends.

In the embodiment of the present application, the high-voltage power supply is a high-voltage battery pack, which can store electrical energy, provide high-voltage electricity demand required by the electric vehicle, and supply power to the pre-charging circuit and the discharging circuit during the power-on of the entire vehicle.

The precharge controllable switch S1 is a relay, which can be connected in series with the multifunctional resistor R to precharge the high voltage capacitor C before the main controllable switch S3 is closed, so as to prevent the high voltage capacitor C from being broken down by the impact of large current.

The main controllable switch S3 is a contactor, which can provide a physical breakpoint when the high-voltage power supply is turned off, and disconnect the high-voltage power supply from the high-voltage electrical appliance module 10. When the high-voltage power supply is turned on and the vehicle meets the power-on conditions, Closing the contact for electric shock connects the main charging circuit to supply power to the high-voltage consumer module 10 .

The discharge controllable switch S2 is a relay, which can be closed to discharge the high-voltage capacitor C after the vehicle is powered off and the precharge controllable switch S1 and the main controllable switch S3 are both turned off. Of course, in other embodiments, the discharge controllable switch S2 may also be an IGBT (Insulated Gate Bipolar Transistor, insulated gate bipolar transistor) or a MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor, metal-oxide semiconductor field effect). transistor), which is not specifically limited in this application.

It can be understood that the high-voltage electrical appliance module 10 is a module composed of high-voltage electrical appliances on the vehicle, and the high-voltage electrical appliance module 10 may include one, two or more sub-modules 11 arranged in parallel, each It can realize the function of an independent high-voltage electrical appliance. That is, each sub-module 11 can be regarded as a high-voltage electrical appliance. Since a plurality of sub-modules 11 are connected in parallel, no interference will occur between any two sub-modules 11 . In other words, each high-voltage electrical appliance works independently. For example, the high-voltage electrical appliance may be, but is not limited to, a DC-DC converter (Direct current-Direct current converter, DC-DC converter), an on-board charger (On-borad Charger, OBC), an air conditioning compressor (Air conditioning). , AC), motor controller (Motor Control Unit, MCU), high-voltage power distribution box (Power Distributor Unit, PDU), body electronic stability system (Electronic Stability Program, ESP), oil pump, water pump, vehicle heater and other electrical appliances.

Please continue to refer to FIG. 2 , in the embodiment of the present application, the high-voltage electrical appliance module 10 includes a plurality of sub-modules 11, and the multiple sub-modules 11 are connected in parallel with each other. Since each sub-module 11 can realize the function of a high-voltage electrical appliance, therefore , each sub-module 11 includes a high-voltage capacitor C. It should be noted that, among the three sub-modules 11 numbered from left to right in FIG. 2 , the first sub-module 11 may be a motor controller, the second sub-module may be a car heater with resistive load, and the third sub-module 11 may be a car heater with resistive load. The modules can be on-board chargers with inductive loads, air conditioner compressors, body electronic stability systems, or DC-DC converters. The actual number and arrangement of the cells are not limited to this, and can be adjusted according to the actual situation, which is not specifically limited in this application.

It can be understood that when the precharging circuit is connected, the high voltage power supply precharges the high voltage capacitors C of all high voltage electrical appliances through the multifunctional resistor R. When the pre-charging circuit is disconnected and the main charging circuit is connected, the high-voltage power supply charges all the high-voltage electrical appliances of the vehicle. The other components are the sub-charging circuits formed by the other components. Specifically, each sub-module 11 includes a capacitor C and at least one sub-charging circuit. FIG. 2 is for illustration only and three sub-charging circuits are drawn in each sub-module 11. Or a sub-charging circuit, the actual number is not limited to this. In other words, it is to charge the entire high-voltage electrical appliance. When the main charging circuit is disconnected and the discharging circuit is connected, the high-voltage capacitors C of all high-voltage electrical appliances are discharged through the multi-function resistor R. Therefore, those skilled in the art can design the number of sub-modules 11 according to actual needs, which can be one sub-module 11, that is, corresponding to a high-voltage electrical appliance on the vehicle, or can be multiple sub-modules 11, that is, corresponding to the entire vehicle All high-voltage electrical appliances above, this application does not make specific restrictions on this.

Further, the high-voltage circuit of the electric vehicle also includes a battery management system (Battery Management System, BMS) (not shown), the battery management system is connected with the pre-charging circuit, the main charging circuit and the discharging circuit, and the battery management system is used for real-time monitoring of the pre-charging. circuit, main charging circuit and discharging circuit for timely adjustment of pre-charging, main charging and discharging. That is, the battery management system is used to control the connection of the precharge circuit, the main charge circuit, and the discharge circuit on and off. The pre-charging circuit, main charging circuit and discharging circuit are controlled by the battery management system, the function definition is clearer, the maintenance is more convenient, and the design cost and maintenance cost are reduced.

Specifically, the battery management system includes a voltage detection unit and a control unit connected to the voltage detection unit. The voltage detection unit is used to detect the voltage of the high-voltage capacitor C to generate a voltage detection value. The control unit is used to realize the function of the battery management system to control the connection of the pre-charging circuit, the main charging circuit and the discharging circuit on and off. Specifically, the control unit is used to control the opening and closing of the precharge controllable switch S1, the main controllable switch S3 and the discharge controllable switch S2.

In a possible implementation, when the whole vehicle meets the power-on conditions, the pre-charge controllable switch S1 is first closed, the pre-charge circuit is connected, and the high-voltage capacitor C of the high-voltage electrical appliance module 10 is pre-charged through the multi-function resistor R, That is to precharge the high-voltage capacitors C of all high-voltage electrical appliances in the vehicle through the multi-function resistor R. Since the control unit can determine whether the voltage detection value is greater than the preset precharge voltage threshold, the control unit controls the precharge controllable switch S1 to turn off and the main controllable switch S3 when the voltage detection value is greater than the preset precharge voltage threshold. It is closed so that the pre-charging circuit is disconnected and the main charging circuit is connected. At this time, the power-on is completed. It can be understood that a voltage greater than the preset pre-charge voltage threshold is the safe voltage range described above that is not easily affected by large currents. When the logic matches, the whole vehicle is powered on. The preset precharge voltage threshold, for example, may be 0.9 times the voltage of the high-voltage power supply.

Then, when the whole vehicle meets the power-off conditions, the main controllable switch S3 is turned off, and the discharge process is entered. Corresponding to the power-on conditions of the entire vehicle, the power-off conditions of the entire vehicle are also consistent with the power-off logic of the entire vehicle. When the power-off logic of the entire vehicle matches, the entire vehicle is powered off.

Then, when the whole vehicle is in the process of discharging, the battery management system detects that the main controllable switch S3 is in an open state and closes the discharge controllable switch S2. The high-voltage capacitors C of all high-voltage electrical appliances are discharged through the multi-function resistor R. Since the control unit can determine whether the detected voltage value is smaller than the preset safety voltage threshold, the control unit determines that when the detected voltage value is smaller than the preset safety voltage threshold, the discharge circuit is disconnected by controlling the discharge controllable switch S2 to be disconnected, and the discharge process Finish.

It can be understood that the range of the safe voltage that is less than the preset safe voltage threshold is the above-mentioned range of safe voltage that is not easy to cause accidental touch. For maintenance, if the high-voltage capacitor C is still charged, the operator may accidentally touch it and cause a safety accident. Therefore, the voltage of the high-voltage capacitor C needs to be discharged to the preset safety voltage threshold to ensure the personal safety of the operator.

In a possible implementation manner, the preset safe voltage threshold is 36V. When the voltage of the high-voltage capacitor C is discharged to less than 36V, the operator will not cause an electric shock accident by accidentally touching the high-voltage capacitor C. In another possible implementation manner, the preset safety voltage threshold is 60V, and when the voltage of the high-voltage capacitor C is discharged to less than 60V, the actual electric shock of the operator will not be caused. It can be understood that the discharge time to 36V and 60V is different. The time required for 36V is relatively long, and the time required for 60V is relatively short. Those skilled in the art can select an appropriate preset safety voltage according to the actual situation. The threshold is not specifically limited in this application.

Further, the high-voltage circuit of the electric vehicle also includes a fuse (not shown). Fuses include main fuses and return fuses. It can be understood that the main charging circuit is provided with a main fuse, and the pre-charging circuit and the discharging circuit are respectively provided with corresponding circuit fuses. In this way, the mutual influence of voltage, current and power in each loop can be effectively avoided. A separate current fuse is set in each circuit, so that when a high voltage fault occurs in any circuit, it will not be implicated with each other, that is, when a short circuit and an overcurrent fault occur in any circuit, the main fuse corresponding to the circuit will be blown in time. A circuit breaker or loop fuse to cut off the loop, so as not to damage other loops in the entire high voltage circuit.

Further, each sub-module 11 is also provided with a corresponding fuse, so that when the circuit corresponding to the sub-module 11 has a short circuit or a serious fire failure, the circuit can be disconnected by cutting off the corresponding circuit fuse, that is, Disconnecting the high-voltage electrical appliance has little effect on the remaining sub-modules 11 , that is, the remaining high-voltage electrical appliance has little impact and the associated loss is small.

It can be understood that in the application of electric vehicles, the fuse, the discharge controllable switch S2, the precharge controllable switch S1, and the main controllable switch S3 are arranged in the same space or box, because the above-mentioned devices are arranged in an easy-to-use Therefore, their respective maintenance costs are low, the layout is easy to design and assemble, and there are strong economic benefits, which also makes the function definition of the high-voltage circuit of the electric vehicle more clear.

The high-voltage circuit of the electric vehicle of the present application integrates the function of the precharge resistor and the function of the discharge resistor into the multi-function resistor R, which can simplify the function that originally required two resistors to be completed by using the same resistor. On the one hand, the function of the multi-function resistor R is integrated, which is easy to install and maintain, and the associated harm is small in the event of failure, which makes the circuit function definition of the high-voltage circuit of the electric vehicle clearer, which is beneficial to the function integration of the whole vehicle circuit; on the other hand, it saves The cost and installation space of a high-power resistor and its control circuit improve the power density and bulk density of the high-voltage circuit of an electric vehicle, with strong economic benefits, high flexibility, and wide application range.

The embodiments of the present utility model have been described in detail above, and specific examples are used to illustrate the principles and implementations of the present utility model. The descriptions of the above embodiments are only used to help understand the method of the present utility model and its core idea; At the same time, for those skilled in the art, according to the idea of the present invention, there will be changes in the specific embodiments and application scope. To sum up, the content of this description should not be construed as a limitation to the present invention.

Claims (10)

1. a high-voltage circuit of an electric vehicle, characterized in that the high-voltage circuit of the electric vehicle comprises a high-voltage power supply, a precharge controllable switch, a discharge controllable switch, a multifunctional resistor and a high-voltage electrical module; the high-voltage power supply, the pre-charge controllable switch, the multi-function resistor and the high-voltage electrical appliance module are connected in series to form a pre-charge circuit of the high-voltage circuit of the electric vehicle; The discharge controllable switch, the multifunctional resistor and the high-voltage electrical appliance module are connected in series to form a discharge loop of the high-voltage circuit of the electric vehicle; The high-voltage electrical module includes a high-voltage capacitor; When the discharge controllable switch is turned off and the precharge controllable switch is turned on, the precharge circuit is connected, so that the high voltage power supply precharges the high voltage capacitor through the multifunctional resistor; When the precharge controllable switch is turned off and the discharge controllable switch is turned on, the discharge circuit is connected to discharge the high-voltage capacitor through the multifunctional resistor. 2. The high-voltage circuit of an electric vehicle according to claim 1, wherein the high-voltage circuit of the electric vehicle further comprises a main controllable switch, the high-voltage power supply, the main controllable switch and the high-voltage electrical appliance The modules are connected in series to form the main charging circuit of the high-voltage circuit of the electric vehicle; When the precharge controllable switch and the discharge controllable switch are disconnected, and the main controllable switch is closed, the main charging circuit is connected to allow the high-voltage power supply to charge the high-voltage electrical module. 3. The high-voltage circuit of an electric vehicle according to claim 2, wherein the high-voltage circuit of the electric vehicle further comprises a battery management system, the battery management system is connected with the pre-charging circuit, the main charging circuit and the The discharge circuit is connected, and the battery management system is used to control the connection of the precharge circuit, the main charge circuit and the discharge circuit on and off. 4 . The high-voltage circuit of an electric vehicle according to claim 3 , wherein the battery management system comprises a voltage detection unit for detecting the voltage of the high-voltage capacitor to generate a voltage detection value. 5 . 5. The high-voltage circuit of an electric vehicle according to claim 4, wherein the high-voltage circuit of the electric vehicle further comprises a control unit, the control unit is connected to the voltage detection unit, and the control unit is used to control The opening and closing of the precharge controllable switch, the main controllable switch and the discharge controllable switch. 6 . The high-voltage circuit of an electric vehicle according to claim 5 , wherein the control unit is capable of judging whether the voltage detection value is greater than a preset pre-charging voltage threshold, and when the voltage detection value is greater than the pre-charging voltage threshold. 7 . When the precharge voltage threshold is set, by controlling the precharge controllable switch to be turned off, the main controllable switch is turned on, so that the precharge circuit is disconnected and the main charge circuit is connected. 7 . The high-voltage circuit of an electric vehicle according to claim 5 , wherein the control unit is capable of judging whether the voltage detection value is smaller than a preset safety voltage threshold, and when the voltage detection value is smaller than the preset safety voltage threshold. 8 . When the safety voltage threshold is reached, the discharge circuit is disconnected by controlling the discharge controllable switch to be disconnected. 8 . The high-voltage circuit of an electric vehicle according to claim 7 , wherein the preset safety voltage threshold is 36V or 60V. 9 . 9 . The high-voltage circuit of an electric vehicle according to claim 2 , wherein the high-voltage electrical appliance module comprises a plurality of sub-modules, a plurality of the sub-modules are connected in parallel with each other, and each of the sub-modules includes one of the high voltage capacitors. 10 . The high-voltage circuit of an electric vehicle according to claim 1 , wherein the discharge controllable switch is a relay, an IGBT or a MOSFET. 11 .

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