CN102981482B - Power supply circuit and method - Google Patents

Abstract

The invention discloses a power supply circuit and method, relates to the field of electronics, and can improve the power supply efficiency of a power supply. The specific scheme is: when the power supply adopts N branches to output in parallel, a sampling unit and an adjustable resistance unit are connected in series on each output branch, and the sampling unit obtains the branch detection signal; the control unit obtains the branch detection signal from the sampling unit. signal, and obtain the reference signal from the reference signal supply unit, and compare the detection signal with the reference signal, when the comparison result is that the detection signal is smaller than the reference signal, the control unit generates a control signal that reduces the branch resistance, when the comparison result is When the detection signal is greater than the reference signal, the control unit generates a control signal to increase the branch resistance; the adjustable resistance unit adjusts the resistance value of the branch resistance according to the control signal input by the control unit until the detection signal is equal to the reference signal. The invention is used for powering the equipment to be powered.

Description

A kind of power supply circuit and method

technical field

The invention relates to the field of electronics, in particular to a power supply circuit and method.

Background technique

As various electronic equipment, such as communication equipment, increase bandwidth and switching capacity requirements, the demand for power supply also increases. Therefore, current communication equipment uses single-channel/dual-channel/multi-channel distributed power supply, distributed The power supply means that the power supply first outputs multiple branches in parallel, and then combines the multiple branches to centrally supply power to the equipment to be powered. In the above power supply mode, the difference in the resistance of each branch leads to uneven current distribution and unequal output voltage of each branch. The branch with low output voltage not only cannot be combined to supply power to the equipment to be powered, but will be equivalent to The load on the branch circuit with high output voltage will cause uneven thermal stress distribution and even damage to the power supply components. Therefore, the distributed power supply must use current sharing technology to make the current of each branch output by the power supply equal, so that the output voltage of each branch is equal.

In the prior art, a DC switching power supply is usually used to achieve the equal current of each branch of the power supply output: without changing the branch resistance, a DC switching power supply is connected in series on each branch of the power supply output. When the branch current is greater than a certain When a threshold value is reached, the output voltage of the DC switching power supply decreases to reduce the branch current; when the branch current is less than a certain threshold, the output voltage of the DC switching power supply increases to increase the branch current, thereby realizing the branch current equal, the output voltage is equal.

In the process of realizing the current sharing of each branch of the above-mentioned power supply, the inventor found that at least the following problems existed in the prior art:

The DC switching power supply is connected in series on each branch of the power supply output to realize the current sharing of each branch. Since the DC switching power supply will consume the power supply of the branch when realizing the current sharing of each branch, so that the power supply after the combination of each branch Compared with the output power of the power supply, the power consumption is greater, resulting in lower power supply efficiency of the power supply.

Contents of the invention

Embodiments of the present invention provide a power supply circuit and method, which can improve the power supply efficiency of a power supply.

In order to achieve the above object, embodiments of the present invention adopt the following technical solutions:

The first aspect of the present invention provides a power supply circuit, including: a power supply, the power supply is connected to N parallel output branches, N is an integer greater than 1, and the power supply circuit also includes:

Sampling unit, adjustable resistance unit, control unit, reference signal supply unit,

A sampling unit and an adjustable resistance unit are connected in series on each output branch, and the location of the adjustable resistance unit is closer to the confluence point of the N output branches than the sampling unit;

The sampling unit is configured to collect a detection signal from the output branch where it is located and output the detection signal to the control unit;

The control unit is configured to obtain a reference signal from the reference signal providing unit, and compare the reference signal with the detection signal; when the comparison result is that the detection signal is smaller than the reference signal, the control unit generates a reduced support The control signal of the branch resistance, when the comparison result is that the detection signal is greater than the reference signal, the control unit generates a control signal for increasing the branch resistance; wherein the reference signal is the average value of the detection signals of the N output branches;

The control unit is also used to input the control signal into the adjustable resistance unit;

The adjustable resistance unit is used to adjust its own resistance value according to the control signal, until the detection voltage is equal to the reference voltage, the control unit stops inputting the control signal to the adjustable resistance unit .

With reference to the first aspect, in a possible implementation manner of the power supply circuit, the detection signal is a detection voltage; the reference signal is a reference voltage.

In combination with the first aspect and the above possible implementation, in another possible implementation, the reference signal providing unit includes: a current sharing bus, a current sharing resistor; one end of the current sharing resistor is connected to the N output branches The output end of the detection voltage of the sampling unit of the road, and the other end is connected to the current sharing bus; the current sharing bus outputs the reference voltage Vref, Vref=V1+V2+V3+...+VN/N, where V1, V2, . . . VN are detection voltages on each output branch respectively.

With reference to the first aspect and the above possible implementation manner, in another possible implementation manner, the power supply circuit includes N reference signal providing units, and each reference signal providing unit is configured to acquire all The detection voltage; the reference signal providing unit is also connected to the reference signal providing unit of other N-1 output branches, and is used to send the detection voltage obtained by itself to the reference signal providing unit of other N-1 output branches, And receive the detection voltage sent by the reference signal providing unit of the other N-1 output branches, the reference signal providing unit also includes a calculation chip, which is used to calculate the average value of N detection voltages, so that the N detection voltages The average value of is used as the reference voltage.

With reference to the first aspect and the foregoing possible implementation manner, in another possible implementation manner, in the power supply circuit, the reference signal providing unit is a reference voltage source, and the reference voltage source provides the reference voltage.

With reference to the first aspect and the above possible implementation manners, in another possible implementation manner, in the power supply circuit, the adjustable resistance unit includes:

The power resistor connected in series on the output branch where it is located and the field effect transistor connected in parallel to the power resistor, the gate of the field effect transistor is connected to the control unit, the drain is connected to the sampling unit, and the source is connected to the The confluence point of N output branches;

or

The field effect transistor connected in series on the output branch, the gate of the field effect transistor is connected to the control unit, the drain is connected to the sampling unit, and the source is connected to the confluence point of the N output branches.

In combination with the first aspect and the above possible implementation manner, in another possible implementation manner, the sampling unit includes a sampling resistor connected in series on the output branch where it is located, and an amplifier; the output terminal of the amplifier is connected to the control unit, and the input terminal of the amplifier is connected in parallel with the sampling resistor.

A second aspect of the present invention provides a power supply method, including:

The power supply is connected to N parallel output branches;

Collect detection signals on each output branch of the power supply; obtain reference signals;

comparing the reference signal with the detection signal;

When the comparison result is that the detection signal is smaller than the reference signal, generate a control signal for reducing the branch resistance, and reduce the branch resistance according to the control signal for reducing the branch resistance; when the comparison result is that the detection signal is greater than the reference signal, generate a rising increase the branch resistance control signal, and increase the branch resistance according to the control signal for increasing the branch resistance; so that the output signals of the N parallel output branches are equal.

With reference to the second aspect, in a possible implementation manner, in the power supply method, the detection signal is a detection voltage; the reference signal is a reference voltage.

With reference to the second aspect and the above possible implementation manner, in another possible implementation manner, the acquiring the reference voltage value includes:

Obtain the detection voltage Vi on each output branch of the power supply;

The detection voltage of each branch obtains the reference voltage Vref by establishing the current sharing bus communication: Vref=V1+V2+V3+...+VN/N.

With reference to the second aspect and the above possible implementation manner, in another possible implementation manner, in the power supply method, the acquiring the reference voltage further includes:

Obtain the detection voltage Vi on each output branch of the power supply;

Calculate the reference voltage Vref through the operation chip: Vref=V1+V2+V3+...+VN/N; establish bus communication between the operation chips of each output branch, so that the mutual transmission of the detection voltage of each output branch and receive.

With reference to the second aspect and the above possible implementation manner, in another possible implementation manner, in the power supply method, the acquiring the reference voltage further includes:

Get the reference voltage provided by the reference voltage source.

In the power supply circuit and method provided by the embodiments of the present invention, when the power supply adopts N branches for parallel output, a sampling unit and an adjustable resistance unit are connected in series on each output branch. The sampling unit obtains the branch detection signal; the control unit respectively obtains the branch detection signal from the sampling unit, obtains the reference signal from the reference signal supply unit, and compares the detection signal with the reference signal to generate a control signal; the adjustable resistance unit is input according to the control unit The control signal adjusts the resistance value on the branch until the detection signal is equal to the reference signal. Compared with the prior art, it avoids the consumption of the output power of the power supply when the DC switching power supply realizes the current equalization of each branch, and improves the power supply. power supply efficiency.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only These are some embodiments of the present invention. For those skilled in the art, other drawings can also be obtained according to these drawings without any creative effort.

Fig. 1 is a schematic diagram of the composition of a power supply circuit in Embodiment 1 of the present invention;

2 is a schematic diagram of another power supply circuit in Embodiment 1 of the present invention;

3 is a schematic diagram of a power supply circuit in Embodiment 2 of the present invention;

FIG. 4 is a schematic diagram of the composition of a reference signal providing unit in Embodiment 2 of the present invention;

FIG. 5 is a schematic diagram of the composition of a reference signal providing unit in Embodiment 2 of the present invention;

FIG. 6 is a schematic diagram of the composition of a reference signal providing unit in Embodiment 2 of the present invention;

7 is a schematic diagram of another power supply circuit in Embodiment 2 of the present invention;

FIG. 8 is a flowchart of a power supply method in Embodiment 3 of the present invention.

Detailed ways

The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some, not all, embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without creative efforts fall within the protection scope of the present invention.

Example 1

An embodiment of the present invention provides a power supply circuit, as shown in FIG. 1 , including: a power supply 11, the power supply 11 is connected to N parallel output branches, N is an integer greater than 1, and the power supply circuit further includes:

Sampling unit 12, adjustable resistance unit 13, control unit 14, reference signal providing unit 15,

Wherein, Fig. 1 simply illustrates with a parallel output of N branch circuits of a direct current power supply. The number of power supply 11 and related parameters can be determined according to the actual needs of the equipment to be powered 17, for example: communication and information equipment usually use one or two output voltages of 60V/48V/24V DC power supply for power supply, when two output voltages are equal When the DC power supply is used for power supply, the two DC power supplies are mutually backup power supplies.

A sampling unit 12 and an adjustable resistance unit 13 are connected in series on each output branch, the adjustable resistance unit 13 is connected to the control unit 14, and the position of the adjustable resistance unit 13 is closer to N output branches than the sampling unit 12 road junction 16;

Wherein, the N branches outputted in parallel by the power supply 11 are combined into one at the confluence point 16 to supply power to the equipment to be powered 17 , and the output parameters of each branch at the confluence point 16 are completely equal. For example: a power supply with an output current of 10A and an output voltage of 10V outputs 10 branches in parallel. After adjustment, the output current of each branch is 1A and the output voltage is 10V. The output of the power supply after the circuit is equal to the output of the power supply, that is, the output current of the power supply after the circuit is combined is 10A, and the output voltage is 10V, so as to supply power to the equipment 17 to be powered.

The sampling unit 12 is connected to the control unit 14, and is used to collect a detection signal from the output branch where it is located and input the detection signal to the control unit 14; wherein the reference signal is the detection of N output branches The average value of the signal. Specifically, the detection signal may be a detection voltage.

Among them, in practical applications, when it is necessary to detect the current of a certain branch, a sampling resistor is usually connected in series with the branch. When the detection current flows through the sampling resistor, the corresponding detection current is obtained by detecting the voltage generated on the sampling resistor. value. It should be noted that in order to reduce the power consumption of the sampling resistors in the sampling unit 12 in the present invention, a sampling resistor device with a resistance value of milliohm level can be selected, and the resistance values of the sampling resistors in each branch are known and equal. In order to facilitate the voltage comparison by the control unit 14, the voltage on the sampling resistor can be amplified to obtain the detection voltage, and the voltage amplification factor is determined according to actual needs. For example: a certain power supply outputs 10 branches in parallel, and a precision resistor with a resistance value of 5mΩ is selected as the sampling resistor in the sampling unit 12 of each branch. When the detection current flowing through the sampling resistor on the first branch is 10A, the first The voltage on the sampling resistor collected by the branch sampling unit 12 is V=5mΩ×10A=50mV. After 100 times of voltage amplification, the detection voltage of the first branch is 5V. Similarly, the detection voltage of each branch is obtained.

The control unit 14 is connected to the adjustable resistance unit 13 and the reference signal providing unit 15. After the control unit 14 obtains the reference signal from the reference signal providing unit 15, it compares the reference signal with the detection signal: when the comparison result When the detection signal is smaller than the reference signal, the control unit 14 generates a control signal for reducing the branch resistance, and when the comparison result is that the detection signal is greater than the reference signal, the control unit 14 generates a control signal for increasing the branch resistance. After the control signal is input to the adjustable resistance unit 13, the adjustable resistance unit 13 can adjust its resistance value according to the control signal until the detection signal is equal to the reference signal. After each branch is combined at the confluence point 16, it supplies power to the equipment to be powered 17 collectively.

The following is a brief description of the parallel output of two branches of a DC power supply. For example: the output voltage of a certain DC power supply is 10V, which is divided into the first branch and the second branch for parallel output; the sampling unit 12 of each branch collects the detection voltage from the sampling resistor: the detection voltage collected by the first branch is 9V , the detection voltage collected by the second branch is 11V; the sampling unit 12 correspondingly inputs the detection voltage to the control unit 14, and the control unit 14 obtains the reference voltage from the reference signal supply unit 15: the first branch sampling unit 12 inputs the detection voltage of 9V To the first branch control unit 14, the second branch sampling unit 12 inputs the 11V detection voltage to the second branch control unit 14, and the corresponding control unit 14 of the first branch and the second branch obtains from the reference signal providing unit 15 The reference voltage of each branch is 10V; the control unit 14 compares the detection voltage of each branch with the reference voltage, and generates a control signal according to the comparison result: the detection voltage of the first branch is 9V less than the reference voltage 10V, and a "reduce branch resistance" control signal is generated , the detection voltage 11V of the second branch is greater than the reference voltage 10V, and a control signal of "increase branch resistance" is generated; the control signal generated by each branch is input into the corresponding adjustable resistance unit 13, so as to control the resistance value of the adjustable resistance unit 13 , until the detection voltage is equal to the reference voltage: the first branch adjustable resistance unit 13 reduces the resistance of the first branch according to the input "reduce branch resistance" control signal until the detection voltage of the first branch is equal to the reference voltage, and the second The branch adjustable resistance unit 13 increases the resistance of the second branch according to the input "increase branch resistance" control signal until the detection voltage of the second branch is equal to the reference voltage. Among them, in the "decrease branch resistance" control signal and "increase branch resistance" control signal, the specific value of the resistance increase/decrease is indicated, and the specific value can be pre-configured according to the actual power supply scene requirements. .

It is explained here that in another implementation scenario of the present invention, as shown in FIG. 2 , the power supply circuit uses two power supply sources. The power supply 111 and the power supply 211 are equally divided into N branches and connected in parallel for output. After each branch achieves current sharing, it performs combined output at the confluence point 16, and the power supply circuits of the power supply 111 and the power supply 112 are mutually backed up, so as to provide The power supply equipment 17 supplies power.

In the power supply circuit provided by the embodiment of the present invention, when the power supply adopts N branch circuits to output in parallel, a sampling unit and an adjustable resistance unit are connected in series on each output branch circuit. The sampling unit obtains the branch detection signal; the control unit respectively obtains the branch detection signal from the sampling unit, obtains the reference signal from the reference signal supply unit, and compares the detection signal with the reference signal to generate a control signal; the adjustable resistance unit is input according to the control unit The control signal adjusts the resistance value on the branch until the detection signal is equal to the reference signal. Compared with the prior art, it avoids the consumption of the output power of the power supply when the DC switching power supply realizes the current equalization of each branch, and improves the power supply. power supply efficiency.

Example 2

An embodiment of the present invention provides a power supply circuit, as shown in FIG. 3 , including: a power supply 21, the power supply 21 is connected to N parallel output branches, N is an integer greater than 1, and the power supply circuit further includes:

A sampling unit 22 , an adjustable resistance unit 23 , a control unit 24 , and a reference signal providing unit 25 . A sampling unit 22 and an adjustable resistance unit 23 are connected in series on each output branch, the adjustable resistance unit 23 is connected to the control unit 24, and the position of the adjustable resistance unit 23 is closer to N output branches than the sampling unit 22 Road junction 26.

The sampling unit 22 is connected to the control unit 24 for collecting detection signals from the output branch where it is located and inputting the detection signals to the control unit 24 .

The control unit 24 is connected to the adjustable resistance unit 23 and the reference signal providing unit 25, for obtaining a reference signal from the reference signal providing unit 25, and comparing the reference signal with the detection signal: when the comparison result is When the detection signal is smaller than the reference signal, the control unit 24 generates a control signal for reducing the branch resistance, and when the comparison result is that the detection signal is greater than the reference signal, the control unit 24 generates a control signal for increasing the branch resistance. The control unit 24 inputs the control signal into the adjustable resistance unit 23, and the adjustable resistance unit 23 adjusts its own resistance value according to the control signal until the detection signal is equal to the reference signal, and each branch is at the confluence point 26 After the circuit is combined, power is supplied to the device 27 to be powered centrally.

Specifically, the detection signal may be a detection voltage; the reference signal may be a reference voltage.

For example: as shown in Figure 3, the sampling unit 22 is made up of the sampling resistor on the series branch and the voltage amplifier connected in parallel with the sampling resistor; Composition, another adjustable resistance unit 23 can also be made up of the field effect transistor connected in series on the branch road, the gate of the field effect transistor is connected to the control unit 24, the drain is connected to the sampling unit 22, and the source is connected to the confluence point 26; the control unit 24 Consists of a voltage comparator.

Among them, in order to reduce the power consumption of the power supply by the sampling resistor, a sampling resistor device with a resistance value of milliohm level can be selected. Usually, the branch current of the power supply power supply is at the ampere level, and the voltage on the sampling resistor is at the millivolt level. In order for the control unit 24 to compare the detection voltage with the reference voltage, an amplifier can be used to amplify the voltage on the sampling resistor and determine it as the detection voltage. In an implementation scenario of the embodiment of the present invention, the sampling unit 22 includes a sampling resistor connected in series on the output branch where it is located, and the voltage on the sampling resistor is collected and determined as the detection voltage, that is, the voltage on the sampling resistor is not amplified.

Wherein, the adjustable resistance unit 23 adopts a field effect tube and a power resistor connected in parallel and then connected in series on the branch, which can reduce the thermal stress on the field effect tube and improve the reliability of the adjustable resistance unit 23, and the resistance adjustment function is realized by the field effect tube. The field effect tube output characteristic curve refers to the relationship curve between the drain current and the drain-source voltage when the gate-source voltage of the field effect tube is constant, which can be roughly divided into: variable resistance area, saturation area, shock pass zone and cutoff zone. When the field effect tube works in the "variable resistance area", the on-resistance value of the field effect tube changes with the voltage between the gate and the source. According to this characteristic, the field effect tube working in the "variable resistance area" The tube can be equivalent to a variable resistor, so when the adjustable resistance unit 23 field effect tube works in the "variable resistance area", the on-resistance value of the field effect tube can be adjusted according to the control signal input by the control unit 24, until the detection voltage is equal to the reference voltage.

In the following, a case where a DC power supply has 2 branch outputs in parallel will be described. For example: the output current of a certain DC power supply is 20A, and the output voltage is 10V, which is divided into the first branch and the second branch for parallel output; the sampling unit 22 of each branch collects the voltage on the sampling resistor and amplifies it to determine the detection Voltage: Take the 1mΩ precision resistor as the sampling resistor, the current flowing through the sampling resistor in the first branch is 9A, then the voltage value on the sampling resistor is 9mV, and the first branch is determined after the voltage on the sampling resistor is amplified by a 1000 times voltage amplifier The detection voltage of the first circuit is 9V, and the current flowing through the sampling resistor in the second branch is 11A, so the voltage value on the sampling resistor is 11mV. After the voltage on the sampling resistor is amplified by a 1000 times voltage amplifier, the detection voltage of the second branch is determined to be 11V The sampling unit 22 inputs the detected voltage to the control unit 24, and the reference signal providing unit 25 provides the control unit 24 with a reference voltage. Assuming that the reference voltage provided by the reference signal supply unit 25 of the first branch and the second branch is 10V, the control unit 24 obtains the reference voltage from the reference signal supply unit 25, then compares the detection voltage with the reference voltage, and according to the comparison result Generate control signals. Taking the input of the positive terminal of the voltage comparator as the reference voltage and the input of the negative terminal as the detection voltage as an example, when the detection voltage is lower than the reference voltage, the control unit 24 outputs a high level, and the corresponding generated control signal is "FET drain-source conduction When the detection voltage is greater than the reference voltage, the control unit 24 outputs a low level, and the corresponding generated control signal is "the drain-source of the field effect transistor is disconnected, and the resistance value of the on-resistance is increased" . Assume here that the detection voltage 9V in the first branch control unit 24 is less than the reference voltage 10V, then generate a signal of “FET drain-source conduction, reduce the on-resistance resistance value”, and the detection voltage in the second branch control unit 24 If 11V is greater than the reference voltage of 10V, the signal "FET drain-source disconnected, increase the on-resistance value" signal is generated; the control signals generated by each branch are input to the adjustable resistance unit 23: the first branch is adjustable Resistor unit 23 reduces the on-resistance value of the first branch adjustable resistance unit 23 field effect transistor according to the input control signal of "FET drain-source conduction, reducing on-resistance value" until the detection voltage Equal to the reference voltage, the second branch adjustable resistance unit 23 raises the second branch adjustable resistance unit 23 according to the input control signal of "the field effect transistor drain-source is disconnected, and the resistance value of the on-resistance is increased". The on-resistance value of the FET until the detection voltage is equal to the reference voltage.

In another case, as shown in FIG. 4 , the reference signal providing unit 25 in the power supply circuit can be composed of a current sharing bus and a current sharing resistor, and one end of the current sharing resistor is connected to the output terminal of the detection voltage of the sampling unit 22 for obtaining the voltage of the sampling unit 22. The input detection voltage, the other end is connected to the current sharing bus, which is used to input the detection voltage to the current sharing bus. For example: the output voltage of a certain DC power supply is 10V, which is divided into 4 branches for parallel output, and the detection voltages of each branch collected by the sampling unit 22 of each branch are respectively: V1=9.8V, V2=10.3V, V3=10.1 V, V4=9.8V, the current-sharing bus obtains the detection voltage of each branch through the current-sharing resistor: V1=9.8V, V2=10.3V V3=10.1V, V4=9.8V, and obtains the reference voltage Vref=(V1+V2 +V3+V4)/4=10V. It is worth noting that: the ideal lossless power supply system is used as an example above to simply illustrate the working principle of the reference signal providing unit 25 .

In another case, as shown in FIG. 5 , the reference signal providing unit 25 may be composed of a computing chip, and the reference signal providing unit 25 is also connected to the sampling unit 22 for obtaining the detection voltage of each branch and calculating the reference voltage. The embodiment of the present invention There is no specific limitation on the computing chip. If a certain software or a certain chip or a certain combination of chips can complete the function of calculating the reference voltage of the above-mentioned computing chip, it is the computing chip described in the embodiment of the present invention. The reference signal providing unit 25 is also connected to the reference signal providing units 25 of other N-1 output branches. After the reference signal providing units 25 of each branch are connected, bus communication is established, and the detection voltage obtained by itself is sent to other branches. The reference signal providing unit 25 of one branch, and receives the detection voltage sent by the reference signal providing unit 25 of other branches. For example: the output voltage of a certain DC power supply is 10V, which is divided into 4 branches for parallel output, and the detection voltage of each branch collected by the sampling unit 22 of each branch is: V1=9.8V, V2=10.3V, V3=10.1V , V4=9.8V, the sampling unit 22 divides the collected detection voltage into two paths and inputs the reference signal supply unit 25 and the control unit 24 respectively; the bus data communication and the acquisition of the reference voltage are illustrated with the first branch: the first branch The reference signal providing unit 25 acquires the detection voltage “V1=9.8V” input by the sampling unit 22 of the first branch, and inputs “V1=9.8V” to the reference signal providing unit 25 of the second branch and the third branch respectively through the communication bus. reference signal providing unit 25 and the reference signal providing unit 25 of the fourth branch. At the same time, the reference signal providing unit 25 of the first branch obtains the detection voltage of the second branch “V2=10.3V” and the third branch through the communication bus. Branch detection voltage "V3=10.1V" and the fourth branch detection voltage "V4=9.8V"; the first branch reference signal supply unit 25 calculates the average value Vp of the four branch detection voltages, Vp=(V1+ V2+V3+V4)/4=10V, and determine the average value Vp of the detection voltage as the reference voltage Vref, that is, Vref=Vp=10V.

Each output branch shown in Figure 5 has a reference signal supply unit. In practical applications, only one reference signal supply unit can be set in the circuit, and a computing chip can be set in the reference signal supply unit to receive the output signals of each output branch. Detect the voltage, calculate the reference voltage, and provide it to each output branch.

In another case, as shown in FIG. 6 , the reference signal providing unit 25 may be composed of a reference voltage source, and the reference voltage source provides the reference voltage. The reference voltage provided by the reference voltage source can be calculated according to the actual situation of the power supply. For example: the output current of a certain DC power supply is 20A, the output voltage is 10V, and it is divided into 4 branches for parallel output. Ideally, the output current of each branch is 5A, and the output voltage is 10V. Then determine the reference voltage source output The current is 5A, and the output reference voltage is 10V.

In the power supply circuit corresponding to Fig. 4, Fig. 5 and Fig. 6, the power supply circuit includes N control units 24 and N reference signal supply units 25, in this case, each output branch is controlled by a control unit Each reference signal supply unit provides a reference signal for a control unit; in the application, a control unit 24 and a reference signal supply unit 25 can also be set for the power supply circuit, and one control unit 24 provides control signals for N output branches. Specifically, as shown in FIG. 7 , the embodiment of the present invention provides another power supply circuit, which includes a control unit 24 and a reference signal supply unit 25 , and one control unit 24 corresponds to N output branches. The reference voltage supply unit 25 is used to obtain the detection voltage input by each branch sampling unit 22 to calculate a reference voltage, and input the reference voltage to the control unit 24 . The control unit 24 obtains the detection voltage from each branch sampling unit 22 and the reference voltage from the reference voltage supply unit 25; and compares the detection voltage with the reference voltage to generate a control signal; the adjustable resistance unit 23 is input according to the control unit 24 The control signal adjusts the resistance values of the branch circuits until the detection voltage is equal to the reference voltage, and each branch circuit is combined at the confluence point 26 to collectively supply power to the equipment 27 to be powered.

It is explained here that the reference signal providing unit 25 of the embodiment of the present invention selects the average value of the detection voltage of each branch as the current sharing standard. In another embodiment of the present invention, the maximum value of the detection voltage of each branch can be used according to actual needs value, the minimum value or a predetermined value as the current sharing standard, which will not be described in detail in this embodiment.

In the power supply circuit provided by the embodiment of the present invention, when the power supply adopts N branch circuits to output in parallel, a sampling unit and an adjustable resistance unit are connected in series on each output branch circuit. The sampling unit obtains the branch detection signal; the control unit respectively obtains the branch detection signal from the sampling unit, obtains the reference signal from the reference signal supply unit, and compares the detection signal with the reference signal to generate a control signal; the adjustable resistance unit is input according to the control unit The control signal adjusts the resistance value on the branch until the detection signal is equal to the reference signal. Compared with the prior art, it avoids the consumption of the output power of the power supply when the DC switching power supply realizes the current equalization of each branch, and improves the power supply. power supply efficiency.

Moreover, in the power supply circuit provided by the embodiment of the present invention, the adjustable resistance unit adopts the parallel connection of the field effect transistor and the power resistor and then connects them in series on the branch circuit, which can reduce the thermal stress on the field effect transistor and improve the reliability of the adjustable resistance unit.

Example 3

An embodiment of the present invention provides a power supply method, as shown in FIG. 8 , including:

301. Collect detection signals on each output branch of the power supply.

The power supply is connected with N parallel output branches.

302. Acquire a reference signal.

303. Compare the detection signal and the reference signal, and generate a control signal according to the comparison result.

304. According to the control signal, control resistance values on the N parallel output branches, so that output signals of the N parallel output branches are equal.

Specifically, when the comparison result is that the detection signal is smaller than the reference signal, a control signal for reducing the branch resistance is generated, and according to the control signal for reducing the branch resistance, the branch resistance is reduced; when the comparison result is that the detection signal is greater than the reference signal , generating a control signal for increasing the branch resistance, and increasing the branch resistance according to the control signal for increasing the branch resistance.

Further, in the power supply method, the detection signal is a detection voltage; the reference signal is a reference voltage.

Further, said obtaining the reference voltage value includes:

Obtain the detection voltage Vi on each output branch of the power supply;

The detection voltage of each branch obtains the reference voltage Vref by establishing the current sharing bus communication: Vref=V1+V2+V3+...+VN/N.

Further, said obtaining the reference voltage also includes:

Obtain the detection voltage Vi on each output branch of the power supply;

Calculate the reference voltage Vref through the operation chip: Vref=V1+V2+V3+...+VN/N; establish bus communication between the operation chips of each output branch, so that the mutual transmission of the detection voltage of each output branch and receive.

Further, said obtaining the reference voltage also includes:

Get the reference voltage provided by the reference voltage source.

It should be noted that for the specific description of some steps in Embodiment 3 of the present invention, reference may be made to the corresponding content in Embodiment 1 and Embodiment 2, and details will not be repeated here in this embodiment of the present invention.

In a power supply method provided by an embodiment of the present invention, when the power supply adopts N branches to output in parallel, a detection signal and a reference signal are obtained on each output branch; the detection signal is compared with the reference signal to generate a control signal; when When the comparison result is that the detection signal is smaller than the reference signal, generate a control signal for reducing the branch resistance, and reduce the branch resistance according to the control signal for reducing the branch resistance; when the comparison result is that the detection signal is greater than the reference signal, generate a rising The control signal of the branch resistance, and according to the control signal of increasing the branch resistance, the branch resistance is increased. By adjusting the resistance value of the branch circuit, the detection signal is equal to the reference signal. Compared with the prior art, it avoids the consumption of the output power of the power supply when the DC switching power supply realizes the current sharing of each branch circuit, and improves the power supply. power supply efficiency.

Through the description of the above embodiments, those skilled in the art can clearly understand that the present invention can be realized by means of software plus necessary general-purpose hardware, and of course also by hardware, but in many cases the former is a better embodiment . Based on this understanding, the essence of the technical solution of the present invention or the part that contributes to the prior art can be embodied in the form of a software product, and the computer software product is stored in a readable storage medium, such as a floppy disk of a computer , a hard disk or an optical disk, etc., including several instructions for enabling a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods described in various embodiments of the present invention.

The above is only a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Anyone skilled in the art can easily think of changes or substitutions within the technical scope disclosed in the present invention. All should be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention should be determined by the protection scope of the claims.

Claims (13)

1. A power supply circuit, the power supply circuit comprising: a power supply, the power supply is connected to N parallel output branches, N is an integer greater than 1, it is characterized in that the power supply circuit also includes: Sampling unit, adjustable resistance unit, control unit, reference signal supply unit, A sampling unit and an adjustable resistance unit are connected in series on each output branch, and the location of the adjustable resistance unit is closer to the confluence point of the N output branches than the sampling unit; The sampling unit is configured to collect a detection signal from the output branch where it is located and output the detection signal to the control unit; The control unit is configured to obtain a reference signal from the reference signal providing unit, and compare the reference signal with the detection signal; when the comparison result is that the detection signal is smaller than the reference signal, the control unit generates a reduced support The control signal of the branch resistance, when the comparison result is that the detection signal is greater than the reference signal, the control unit generates a control signal for increasing the branch resistance; wherein the reference signal is the average value of the detection signals of the N output branches; The control unit is also used to input the control signal into the adjustable resistance unit; The adjustable resistance unit is used to adjust its own resistance value according to the control signal until the control unit stops inputting the control signal to the adjustable resistance unit when the detected voltage is equal to the reference voltage. 2. The power supply circuit according to claim 1, wherein the detection signal is a detection voltage; the reference signal is a reference voltage. 3. The power supply circuit according to claim 2, wherein the reference signal providing unit comprises: a current sharing bus, a current sharing resistor; one end of the current sharing resistor is connected to the sampling unit of the N output branches The output end of the detection voltage, the other end is connected to the current sharing bus; the current sharing bus outputs the reference voltage Vref, Vref=(V1+V2+V3+...+VN)/N, where V1, V2,...VN are respectively is the detection voltage on each output branch. 4. The power supply circuit according to claim 2, wherein the power supply circuit comprises N reference signal supply units, each reference signal supply unit is used to obtain the detection voltage from the sampling unit of the branch; The reference signal providing unit is also connected to the reference signal providing units of other N-1 output branches, and is used to send the detection voltage obtained by itself to the reference signal providing units of other N-1 output branches, and receive other N-1 output branches. The detection voltage sent by the reference signal supply unit of one output branch, the reference signal supply unit also includes a calculation chip for calculating the average value of the N detection voltages, so that the average value of the N detection voltages is used as the the above reference voltage. 5. The power supply circuit according to claim 2, characterized in that, the power supply circuit comprises a reference signal providing unit, and the reference signal providing unit is used to obtain N detections from N sampling units in the power supply circuit Voltage; the reference signal providing unit further includes a computing chip, configured to calculate an average value of N detection voltages, so as to use the average value of the N detection voltages as the reference voltage. 6. The power supply circuit according to claim 2, wherein the reference signal providing unit is a reference voltage source, and the reference voltage source provides the reference voltage. 7. The power supply circuit according to claim 2, wherein the adjustable resistance unit comprises: The power resistor connected in series on the output branch where it is located and the field effect transistor connected in parallel to the power resistor, the gate of the field effect transistor is connected to the control unit, the drain is connected to the sampling unit, and the source is connected to the The confluence point of N output branches; or The field effect transistor connected in series on the output branch, the gate of the field effect transistor is connected to the control unit, the drain is connected to the sampling unit, and the source is connected to the confluence point of the N output branches. 8. The power supply circuit according to claim 2, wherein the sampling unit includes a sampling resistor connected in series with the output branch, and an amplifier; the output terminal of the amplifier is connected to the control unit, and the amplifier The input terminal of is connected in parallel on the sampling resistor. 9. A power supply method, characterized in that, comprising: The power supply is connected to N parallel output branches; Collect detection signals on each output branch of the power supply; obtain a reference signal; wherein the reference signal is an average value of detection signals of N output branches; comparing the reference signal with the detection signal; When the comparison result is that the detection signal is smaller than the reference signal, generate a control signal for reducing the branch resistance, and reduce the branch resistance according to the control signal for reducing the branch resistance; when the comparison result is that the detection signal is greater than the reference signal, generate a rising increase the branch resistance control signal, and increase the branch resistance according to the control signal for increasing the branch resistance; so that the output signals of the N parallel output branches are equal. 10. The power supply method according to claim 9, wherein the detection signal is a detection voltage; the reference signal is a reference voltage. 11. The power supply method according to claim 10, wherein said obtaining the reference signal comprises: Obtain the detection voltage Vi on each output branch of the power supply; The detection voltage of each branch obtains the reference voltage Vref by establishing the current sharing bus communication: Vref=(V1+V2+V3+...+VN)/N. 12. The power supply method according to claim 10, wherein said obtaining the reference signal further comprises: Obtain the detection voltage Vi on each output branch of the power supply; The reference voltage Vref is calculated by the computing chip: Vref=(V1+V2+V3+...+VN)/N; bus communication is established between the computing chips of each output branch, so that the detection voltages of each output branch can be sent to each other and receive. 13. The power supply method according to claim 10, wherein said obtaining the reference signal further comprises: Get the reference voltage provided by the reference voltage source.