CN116760300A

CN116760300A - Auxiliary power supply circuit, auxiliary power supply device and energy storage inverter

Info

Publication number: CN116760300A
Application number: CN202310722930.7A
Authority: CN
Inventors: 李圣根; 江辉; 黄惟光
Original assignee: Xinyi Power Storage Shenzhen Co ltd
Current assignee: Xinyi Power Storage Shenzhen Co ltd
Priority date: 2023-06-16
Filing date: 2023-06-16
Publication date: 2023-09-15

Abstract

The application is suitable for the technical field of power electronics, and provides an auxiliary power supply circuit, an auxiliary power supply device and an energy storage inverter. The first isolation module in the auxiliary power supply circuit is respectively connected with the same-name end of the primary winding of the transformer, the first switch module and the first power supply, the first switch module is respectively electrically connected with the different-name end of the primary winding of the transformer, the second switch module, the first rectifying and filtering module, the second isolation module, the voltage dividing module and the second power supply, the same-name end of the first secondary winding of the transformer is electrically connected with the second isolation module, the second switch module is respectively electrically connected with the different-name end of the first secondary winding of the transformer, the voltage dividing module and the second rectifying and filtering module, the same-name end and the different-name end of the second secondary winding of the transformer are electrically connected with the first rectifying and filtering module, and the same-name end and the different-name end of the third secondary winding of the transformer are electrically connected with the second rectifying and filtering module. The application solves the problems of overlarge volume and overlarge cost of the traditional auxiliary power supply system.

Description

Auxiliary power supply circuit, auxiliary power supply device and energy storage inverter

Technical Field

The application belongs to the technical field of power electronics, and particularly relates to an auxiliary power supply circuit, an auxiliary power supply device and an energy storage inverter.

Background

In the energy storage inverter, an auxiliary power supply system is generally adopted to supply power to the controller, the input of the auxiliary power supply system is high-low voltage mixed input, in order to solve the problem of high-low voltage mixed input, the circuit structure of the existing auxiliary power supply system is realized by adopting two transformers, and the size and the cost of the auxiliary power supply system are overlarge.

Disclosure of Invention

The embodiment of the application provides an auxiliary power supply circuit, an auxiliary power supply device and an energy storage inverter, which can solve the problems of overlarge volume and overlarge cost of the existing auxiliary power supply system.

In a first aspect, an embodiment of the present application provides an auxiliary power supply circuit, including a transformer, a first isolation module, a second isolation module, a first switch module, a second switch module, a first rectifying and filtering module, a second rectifying and filtering module, and a voltage dividing module; the first isolation module is electrically connected with the homonymous end of the primary winding of the transformer, the first switch module and the first power supply respectively, the first switch module is electrically connected with the homonymous end of the primary winding of the transformer, the second switch module, the first rectifying and filtering module, the second isolation module, the voltage dividing module and the second power supply respectively, the homonymous end of the first secondary winding of the transformer is electrically connected with the second isolation module, the second switch module is electrically connected with the homonymous end of the first secondary winding of the transformer, the voltage dividing module and the second rectifying and filtering module respectively, the homonymous end and the homonymous end of the second secondary winding of the transformer are electrically connected with the first rectifying and filtering module respectively, and the homonymous end of the third secondary winding of the transformer are electrically connected with the second rectifying and filtering module respectively;

When the first power supply and the second power supply are used for supplying power simultaneously, the first power supply is used for waking up the auxiliary power supply circuit, and the first isolation module is used for conducting according to a first power supply voltage provided by the first power supply and transmitting the first power supply voltage to the homonymous end of the primary winding of the transformer; the second isolation module is used for isolating the first secondary winding of the transformer and the second power supply; the voltage division module is used for outputting a first voltage to the second switch module; the second switch module is used for being disconnected according to the first voltage; the first switch module is used for receiving the first power supply voltage, the target voltage and the second power supply voltage provided by the second power supply, periodically switching on or off according to the first power supply voltage and the target voltage, enabling a primary winding of the transformer to periodically store energy or release energy, and enabling the target voltage to be kept stable through a second secondary winding of the transformer and the first rectifying and filtering module; when the second power supply voltage reaches a preset voltage, the first switch module is disconnected, the first isolation module isolates the primary winding of the transformer from the first power supply, the second isolation module is conducted according to the second power supply voltage and transmits the second power supply voltage to the same-name end of the first secondary winding of the transformer, the voltage division module outputs a second voltage to the second switch module according to the second power supply voltage, the second rectification filter module outputs a third voltage to the second switch module, and the second switch module is periodically conducted or disconnected according to the second voltage, the third voltage and the target voltage, so that the first secondary winding of the transformer periodically stores energy or releases energy, and the target voltage is kept stable through the second secondary winding of the transformer and the first rectification filter module, wherein the target voltage is the voltage output by the first rectification filter module.

In a possible implementation manner of the first aspect, the first switching module includes a first PWM control unit, a first switching unit, a first feedback unit, a starting unit, a first detection unit, and a second detection unit; the first PMW control unit is respectively and electrically connected with the starting unit, the first switch unit, the first feedback unit, the first detection unit and the second detection unit, the starting unit is respectively and electrically connected with the first isolation module, the first power supply, the first detection unit, the first feedback unit, the first rectifying and filtering module and the second switch module, the second detection unit is respectively and electrically connected with the second isolation module, the second power supply and the voltage division module, and the first switch unit is electrically connected with a synonym end of a primary winding of the transformer;

when the first power supply and the second power supply are used for supplying power simultaneously, the first power supply is used for waking up the auxiliary power supply circuit, and the starting unit is used for conducting according to a first power supply voltage provided by the first power supply and outputting a starting voltage to the first PWM control unit; the first PWM control unit is used for starting working according to the starting voltage and outputting a first PWM control signal to the first switch unit; the first switch unit is used for being periodically turned on or turned off according to the first PWM control signal so as to enable a primary winding of the transformer to periodically store energy or release energy, and the target voltage is output through a second secondary winding of the transformer and the first rectifying and filtering module; when the starting unit receives the target voltage, the starting unit is disconnected and transmits the target voltage to the first PWM control unit; the first feedback unit is used for outputting a first feedback signal to the first PWM control unit according to the target voltage; the first PWM control unit is used for adjusting the first PWM control signal according to the first feedback signal, so as to adjust the on time of the first switch unit, and finally, the target voltage is kept stable; the first detection unit is used for receiving the first power supply voltage, detecting whether the first power supply is in low voltage or under voltage according to the first power supply voltage, and when the first power supply is in low voltage or under voltage, the first detection unit pulls down the first PWM control unit to the ground so that the first PWM control unit stops working; the second detection unit is used for receiving a second power supply voltage provided by the second power supply, and when the second power supply voltage reaches the preset voltage, the second detection unit pulls down the first PWM control unit to the ground so that the first PWM control unit stops working.

In a possible implementation manner of the first aspect, the first switching unit includes a first switching tube, a first resistor, a second resistor, and a first capacitor; the control end of the first switching tube is electrically connected with the first PWM control unit, the second conducting end of the first switching tube is electrically connected with the synonym end of the primary winding of the transformer, the first conducting end of the first switching tube is electrically connected with the first end of the first resistor and the first end of the second resistor respectively, the second end of the second resistor and the first end of the first capacitor are electrically connected with the first PWM control unit, and the second end of the first capacitor and the second end of the first resistor are electrically connected with a first power supply.

In a possible implementation manner of the first aspect, the second switching module includes a second PWM control unit, a second switching unit, a third switching unit, and a second feedback unit; the second PWM control unit is respectively and electrically connected with the second switch unit, the third switch unit and the second feedback unit, the second switch unit is electrically connected with the synonym end of the first secondary winding of the transformer, the third switch unit is respectively and electrically connected with the second rectifying and filtering module and the voltage dividing module, and the second feedback unit is respectively and electrically connected with the first rectifying and filtering module and the first switch module;

When the first power supply and the second power supply are used for supplying power simultaneously, the first power supply is used for waking up the auxiliary power supply circuit, and the voltage dividing module is used for outputting the first voltage to the third switch unit; the third switch unit is used for being disconnected according to the first voltage; when the second power voltage provided by the second power supply reaches the preset voltage, the voltage dividing module outputs the second voltage to the third switching unit according to the second power voltage, the second rectifying and filtering module outputs the third voltage to the third switching unit, so that the third switching unit is conducted according to the second voltage and transmits the third voltage to the second PWM control unit, the second PWM control unit is started to work according to the third voltage and outputs a second PWM control signal to the second switching unit, the second switching unit is periodically conducted or disconnected according to the second PWM control signal, the first secondary winding of the transformer is enabled to periodically store energy or release energy, the second feedback unit outputs the target voltage to the second PWM control unit according to the target voltage through the second secondary winding of the transformer and the first rectifying and filtering module, the second PWM control unit is enabled to maintain the target voltage according to the second PWM control signal, and the second feedback unit is enabled to maintain the target PWM control signal to be conducted stably.

In a possible implementation manner of the first aspect, the second switching unit includes a second switching tube, a third resistor, a fourth resistor, and a second capacitor; the control end of the second switching tube is electrically connected with the second PWM control unit, the second conducting end of the second switching tube is electrically connected with the synonym end of the first secondary winding of the transformer, the first conducting end of the second switching tube is electrically connected with the first end of the third resistor and the first end of the fourth resistor respectively, the second end of the fourth resistor and the first end of the second capacitor are electrically connected with the second PWM control unit, and the second end of the third resistor and the second end of the second capacitor are electrically connected with a second power supply.

In a possible implementation manner of the first aspect, the third switching unit includes a third switching tube; the control end of the third switching tube is electrically connected with the voltage dividing module, the first conducting end of the third switching tube is electrically connected with the second rectifying and filtering module, and the second conducting end of the third switching tube is electrically connected with the second PWM control unit.

In a possible implementation manner of the first aspect, the voltage dividing module includes a fifth resistor and a sixth resistor; the first end of the fifth resistor is electrically connected with the second power supply, the second isolation module and the first switch module respectively, the second end of the fifth resistor is electrically connected with the first end of the sixth resistor and the second switch module respectively, and the second end of the sixth resistor is electrically connected with the second power supply.

In a possible implementation manner of the first aspect, the auxiliary power supply circuit further includes a filtering module; the filtering module is electrically connected with the second isolation module, the second power supply, the voltage division module and the first switch module respectively.

In a second aspect, an embodiment of the present application provides an auxiliary power supply apparatus, including an auxiliary power supply circuit as set forth in any one of the first aspects.

In a third aspect, an embodiment of the present application provides an energy storage inverter, including the auxiliary power unit according to the second aspect.

Compared with the prior art, the embodiment of the application has the beneficial effects that:

the embodiment of the application provides an auxiliary power supply circuit which comprises a transformer, a first isolation module, a second isolation module, a first switch module, a second switch module, a first rectifying and filtering module, a second rectifying and filtering module and a voltage dividing module. The first isolation module is electrically connected with the same-name end of the primary winding of the transformer, the first switch module and the first power supply respectively, the first switch module is electrically connected with the different-name end of the primary winding of the transformer, the second switch module, the first rectifying and filtering module, the second isolation module, the voltage dividing module and the second power supply respectively, the same-name end of the first secondary winding of the transformer is electrically connected with the second isolation module, the second switch module is electrically connected with the different-name end of the first secondary winding of the transformer, the voltage dividing module and the second rectifying and filtering module respectively, the same-name end and the different-name end of the second secondary winding of the transformer are electrically connected with the first rectifying and filtering module, and the same-name end and the different-name end of the third secondary winding of the transformer are electrically connected with the second rectifying and filtering module.

Specifically, when only the first power supply is used for supplying power, the first isolation module is used for conducting according to the first power supply voltage provided by the first power supply and transmitting the first power supply voltage to the homonymous end of the primary winding of the transformer; the second isolation module is used for isolating the first secondary winding of the transformer and the second power supply; the voltage division module is used for outputting a first voltage to the second switch module; the second switch module is used for being disconnected according to the first voltage; the first switch module is used for receiving a first power supply voltage and a target voltage, periodically switching on or switching off according to the first power supply voltage and the target voltage, enabling a primary winding of the transformer to periodically store energy or release energy, and enabling the target voltage to be kept stable through a second secondary winding of the transformer and the first rectifying and filtering module, wherein the target voltage is the voltage output by the first rectifying and filtering module, and the first power supply voltage is low-voltage direct-current voltage.

When the first power supply and the second power supply are used for supplying power simultaneously, the first power supply is adopted for waking up the auxiliary power supply circuit, and the first isolation module is used for conducting according to the first power supply voltage and transmitting the first power supply voltage to the homonymous end of the primary winding of the transformer; the second isolation module is used for isolating the first secondary winding of the transformer and the second power supply; the voltage division module is used for outputting a first voltage to the second switch module; the second switch module is used for being disconnected according to the first voltage; the first switch module is used for receiving a first power supply voltage, a target voltage and a second power supply voltage provided by a second power supply, periodically switching on or switching off according to the first power supply voltage and the target voltage, enabling a primary winding of the transformer to periodically store energy or release energy, and enabling the target voltage to be kept stable through a second secondary winding of the transformer and the first rectifying and filtering module; when the second power supply voltage reaches the preset voltage, the first switch module is disconnected, the first isolation module isolates the primary winding of the transformer from the first power supply, the second isolation module is conducted according to the second power supply voltage and transmits the second power supply voltage to the same-name end of the first secondary winding of the transformer, the voltage division module outputs the second voltage to the second switch module according to the second power supply voltage, the second rectification filter module outputs the third voltage to the second switch module, the second switch module is periodically conducted or disconnected according to the second voltage, the third voltage and the target voltage, the first secondary winding of the transformer is enabled to store energy or release energy periodically, and the target voltage is kept stable through the second secondary winding of the transformer and the second rectification filter module, wherein the second power supply voltage is a direct current bus voltage.

When only the second power supply is used for supplying power, the first isolation module is used for isolating the primary winding of the transformer and the first power supply; the second isolation module is used for conducting according to the second power supply voltage and transmitting the second power supply voltage to the homonymous end of the first secondary winding of the transformer; the first switch module is used for receiving the first power supply voltage and the second power supply voltage and is disconnected according to the first power supply voltage or the second power supply voltage; the voltage division module is used for outputting a second voltage to the second switch module according to the second power supply voltage; the second rectifying and filtering module is used for outputting a third voltage to the second switch module; the second switch module is used for periodically switching on or switching off according to the second voltage, the third voltage and the target voltage, so that the first secondary winding of the transformer periodically stores energy or releases energy, and the target voltage is kept stable through the second secondary winding of the transformer and the second rectifying and filtering module.

As can be seen from the above, the circuit structure of the auxiliary power supply circuit provided by the embodiment of the application is realized by only one transformer, and the volume and cost of the auxiliary power supply circuit are reduced on the premise of realizing high-low voltage mixed input.

In summary, the auxiliary power supply circuit provided by the embodiment of the application solves the problems of overlarge volume and overlarge cost of the existing auxiliary power supply system.

It will be appreciated that the advantages of the second to third aspects may be found in the relevant description of the first aspect, and are not described in detail herein.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are needed in the embodiments or the description of the prior art will be briefly described below, it being obvious that the drawings in the following description are only some embodiments of the present application, and that other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

FIG. 1 is a schematic block diagram of a prior art auxiliary power system;

FIG. 2 is a schematic block diagram of a prior art auxiliary power system;

FIG. 3 is a schematic block diagram of an auxiliary power circuit according to an embodiment of the present application;

FIG. 4 is a schematic block diagram of an auxiliary power circuit provided in another embodiment of the application;

FIG. 5 is a schematic block diagram of an auxiliary power circuit provided in another embodiment of the present application;

FIG. 6 is a schematic block diagram of an auxiliary power circuit provided in another embodiment of the present application;

fig. 7 is a schematic circuit connection diagram of an auxiliary power supply circuit according to an embodiment of the application.

In the figure: 10. a first isolation module; 20. a second isolation module; 30. a first switch module; 301. a first PWM control unit; 302. a first switching unit; 303. a first feedback unit; 304. a starting unit; 305. a first detection unit; 306. a second detection unit; 40. a second switch module; 401. a second PWM control unit; 402. a second switching unit; 403. a third switching unit; 404. a second feedback unit; 50. a first rectifying and filtering module; 60. the second rectifying and filtering module; 70. a voltage dividing module; 80. a first power supply; 90. a second power supply; 100. and a filtering module.

Detailed Description

In the following description, for purposes of explanation and not limitation, specific details are set forth such as the particular system architecture, techniques, etc., in order to provide a thorough understanding of the embodiments of the present application. It will be apparent, however, to one skilled in the art that the present application may be practiced in other embodiments that depart from these specific details. In other instances, detailed descriptions of well-known systems, devices, circuits, and methods are omitted so as not to obscure the description of the present application with unnecessary detail.

It should be understood that the terms "comprises" and/or "comprising," when used in this specification and the appended claims, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.

It should also be understood that the term "and/or" as used in the present specification and the appended claims refers to any and all possible combinations of one or more of the associated listed items, and includes such combinations.

As used in the present description and the appended claims, the term "if" may be interpreted in context as "when …" or "upon" or "in response to a determination" or "in response to detection. Similarly, the phrase "if a determination" or "if a [ described condition or event ] is detected" may be interpreted in the context of meaning "upon determination" or "in response to determination" or "upon detection of a [ described condition or event ]" or "in response to detection of a [ described condition or event ]".

Furthermore, the terms "first," "second," "third," and the like in the description of the present specification and in the appended claims, are used for distinguishing between descriptions and not necessarily for indicating or implying a relative importance.

Reference in the specification to "one embodiment" or "some embodiments" or the like means that a particular feature, structure, or characteristic described in connection with the embodiment is included in one or more embodiments of the application. Thus, appearances of the phrases "in one embodiment," "in some embodiments," "in other embodiments," and the like in the specification are not necessarily all referring to the same embodiment, but mean "one or more but not all embodiments" unless expressly specified otherwise. The terms "comprising," "including," "having," and variations thereof mean "including but not limited to," unless expressly specified otherwise.

For the auxiliary power supply system with high-low voltage mixed input, two implementation modes are generally adopted, one implementation mode is to adopt two independent power supply modules, a schematic block diagram is shown in fig. 1, and the working principle is that the low-voltage power supply modules and the high-voltage power supply modules form two independent power supply circuits for supplying power to a controller in an energy storage inverter, and the two independent power supply circuits are isolated through high-power diodes. The other is to adopt two independent power supply modules, the principle of which is shown in fig. 2, and the working principle is that the low voltage is increased to high voltage by a booster circuit in the low voltage power supply module, then the high voltage power supply module is powered, and finally the controller in the energy storage inverter is powered by the high voltage power supply module. Both of these implementations require the use of two transformers, resulting in an auxiliary power system that is bulky and costly. The high voltage in the high-low voltage mixed input is a high-voltage dc voltage, for example, the high-voltage dc voltage is 220V, and the low voltage is a low-voltage dc voltage, for example, the low-voltage dc voltage is 48V, 24V, or 12V.

In view of the above problems, an embodiment of the present application provides an auxiliary power supply circuit, as shown in fig. 3, including a transformer TX1, a first isolation module 10, a second isolation module 20, a first switch module 30, a second switch module 40, a first rectifying and filtering module 50, a second rectifying and filtering module 60, and a voltage dividing module 70. The first isolation module 10 is electrically connected with the same-name end of the primary winding N1 of the transformer TX1, the first switch module 30 and the first power supply 80, the first switch module 30 is electrically connected with the different-name end of the primary winding N1 of the transformer TX1, the second switch module 40, the first rectifying and filtering module 50, the second isolation module 20, the voltage division module 70 and the second power supply 90, the same-name end of the first secondary winding N2 of the transformer TX1 is electrically connected with the second isolation module 20, the second switch module 40 is electrically connected with the different-name end of the first secondary winding N2 of the transformer TX1, the voltage division module 70 and the second rectifying and filtering module 60, the same-name end and the different-name end of the second secondary winding N3 of the transformer TX1 are electrically connected with the first rectifying and filtering module 50, and the same-name end and the different-name end of the third secondary winding N4 of the transformer TX1 are electrically connected with the second rectifying and filtering module 60. Wherein the first power source 80 is a battery. The second power supply 90 is powered by a dc bus voltage. The transformer TX1 is a flyback transformer.

Specifically, when only the first power supply 80 is used for supplying power, the first isolation module 10 is configured to conduct according to the first power supply voltage provided by the first power supply 80, and transmit the first power supply voltage to the same-name end of the primary winding N1 of the transformer TX 1. The second isolation module 20 is configured to isolate the first secondary winding N2 of the transformer TX1 from the second power supply 90, such that the second power supply 90 cannot be conducted with the first secondary winding N2 of the transformer TX1, and no voltage is applied to the second power supply 90. The voltage dividing module 70 is configured to output the first voltage to the second switching module 40. The second switching module 40 is configured to be turned off according to the first voltage. The first switch module 30 is configured to receive a first power voltage and a target voltage, and periodically switch on or off according to the first power voltage and the target voltage, so that the primary winding N1 of the transformer TX1 periodically stores energy or releases energy, and the target voltage is maintained stable through the coupling action of the second secondary winding N3 of the transformer TX1 and the rectifying and filtering action of the first rectifying and filtering module 50, wherein the target voltage is a voltage output by the first rectifying and filtering module 50 and is used for supplying power to a controller in the energy storage inverter, and the first power voltage is a low-voltage direct-current voltage, for example, the low-voltage direct-current voltage is 48V, 24V or 12V.

When the first power supply 80 and the second power supply 90 are used for supplying power at the same time, the first power supply 80 is used for waking up the auxiliary power supply circuit, and when the second power supply 90 supplies the second power supply voltage to reach the preset voltage, the power supply loop of the first power supply 80 is closed, and the second power supply 90 is used for supplying power. The specific working principle is that the first isolation module 10 is configured to conduct according to a first power voltage and transmit the first power voltage to the same-name end of the primary winding N1 of the transformer TX 1. The second isolation module 20 is configured to isolate the first secondary winding N2 of the transformer TX1 from the second power supply 90, such that the second power supply 90 cannot be conducted with the first secondary winding N2 of the transformer TX1, and no voltage is applied to the second power supply 90. The voltage dividing module 70 is configured to output the first voltage to the second switching module 40. The second switching module 40 is configured to be turned off according to the first voltage. The first switch module 30 is configured to receive the first power voltage, the target voltage, and the second power voltage provided by the second power supply 90, periodically turn on or off according to the first power voltage and the target voltage, periodically store energy in or release energy from the primary winding N1 of the transformer TX1, and maintain the target voltage stable through the second secondary winding N3 of the transformer TX1 and the first rectifying and filtering module 50; when the second power supply voltage reaches the preset voltage, the first switch module 30 is turned off, i.e. the power supply loop of the first power supply 80 is closed, so that the power consumption of the circuit can be reduced, the first isolation module 10 isolates the primary winding N1 of the transformer TX1 from the first power supply 80, so that the first power supply 80 cannot be conducted with the primary winding N1 of the transformer TX1, the second isolation module 20 is conducted according to the second power supply voltage and transmits the second power supply voltage to the same-name end of the first secondary winding N2 of the transformer TX1, the voltage division module 70 outputs the second voltage to the second switch module 40 according to the second power supply voltage, the second rectifying and filtering module 60 is used for outputting the third voltage to the second switch module 40, and the second switch module 40 is periodically conducted or turned off according to the second voltage, the third voltage and the target voltage, so that the first secondary winding N2 of the transformer TX1 periodically stores energy or releases energy, and the target voltage is maintained stably by the coupling action of the second secondary winding N3 of the transformer TX1 and the rectifying and filtering action of the first rectifying and filtering module 50. The second power voltage is a dc bus voltage, for example, 220V.

When only the second power supply 90 is used to supply power, the first isolation module 10 is used to isolate the primary winding N1 of the transformer TX1 from the first power supply 80, so that the first power supply 80 cannot be conducted with the primary winding N1 of the transformer TX 1. The second isolation module 20 is configured to be turned on according to the second power voltage, and transmit the second power voltage to the same-name end of the first secondary winding N2 of the transformer TX 1. The first switch module 30 is configured to receive a first power voltage and a second power voltage, and disconnect according to the first power voltage or the second power voltage. The voltage dividing module 70 is configured to output a second voltage to the second switch module 40 according to the second power voltage. The second rectifying and filtering module 60 is configured to output a third voltage to the second switching module 40. The second switch module 40 is configured to periodically turn on or off according to the second voltage, the third voltage and the target voltage, so that the first secondary winding N2 of the transformer TX1 periodically stores energy or releases energy, and the target voltage is maintained stable through the coupling action of the second secondary winding N3 of the transformer TX1 and the rectifying and filtering action of the first rectifying and filtering module 50.

As can be seen from the above, the circuit structure of the auxiliary power supply circuit provided by the embodiment of the application is realized by only one transformer TX1, and the volume and cost of the auxiliary power supply circuit are reduced on the premise of realizing high-low voltage hybrid input.

It should be noted that the preset voltage may be set according to practical situations, which is not limited in the present application.

As shown in fig. 7, the first isolation module 10 includes a first diode D1. The positive pole of the first diode D1 is electrically connected to the positive pole of the first power supply 80 and the first switch module 30, respectively, the negative pole of the first diode D1 is electrically connected to the same-name end of the primary winding N1 of the transformer TX1, and the negative pole of the first power supply 80 is electrically connected to the first power supply. Wherein the first power ground is a low voltage ground.

Specifically, when only the first power supply 80 is used for supplying power, the first diode D1 is turned on in the forward direction according to the first power supply voltage provided by the first power supply 80, and transmits the first power supply voltage to the same-name end of the primary winding N1 of the transformer TX 1.

When the first power supply 80 and the second power supply 90 are used for supplying power simultaneously, the first power supply 80 is used for waking up the auxiliary power supply circuit, the first diode D1 is conducted in the forward direction, and the first power supply voltage is transmitted to the homonymous end of the primary winding N1 of the transformer TX 1. When the second power voltage provided by the second power supply 90 reaches the preset voltage, the first switch module 30 is turned off, i.e. the first power supply 80 is not used for supplying power, and at this time, the second power supply 90 is used for supplying power, the first diode D1 is turned off reversely, and the primary winding N1 of the isolation transformer TX1 and the first power supply 80 are isolated, so that the primary winding N1 of the isolation transformer TX1 and the first power supply 80 cannot be conducted.

When only the second power supply 90 is used for supplying power, the first diode D1 is turned off reversely, and the primary winding N1 of the isolation transformer TX1 and the first power supply 80 are isolated, so that the primary winding N1 of the isolation transformer TX1 and the first power supply 80 cannot be turned on.

It should be noted that the first isolation module 10 may be replaced by another module that performs its function, and is not limited thereto.

As shown in fig. 7, the second isolation module 20 includes a second diode D2. The positive pole of the second diode D2 is electrically connected to the positive pole of the second power supply 90, the voltage dividing module 70 and the first switch module 30, respectively, the negative pole of the second diode D2 is electrically connected to the same-name end of the first secondary winding N2 of the transformer TX1, and the negative pole of the second power supply 90 is electrically connected to the second power supply. Wherein the second power ground is a high voltage ground.

Specifically, when only the first power supply 80 is used for supplying power, the second diode D2 is turned off reversely, so that the first secondary winding N2 of the isolation transformer TX1 and the second power supply 90 cannot be turned on.

When the first power supply 80 and the second power supply 90 are used for supplying power at the same time, the first power supply 80 is used for waking up the auxiliary power supply circuit, the second diode D2 is turned off reversely, and the first secondary winding N2 of the isolation transformer TX1 and the second power supply 90 are disconnected, so that the first secondary winding N2 of the isolation transformer TX1 and the second power supply 90 cannot be conducted. When the second power voltage provided by the second power supply 90 reaches the preset voltage, the first switch module 30 is turned off, i.e. the first power supply 80 is not used for supplying power, and at this time, the second power supply 90 is used for supplying power, the second diode D2 is turned on in the forward direction, and the second power voltage is transmitted to the same-name end of the first secondary winding N2 of the transformer TX 1.

When only the second power supply 90 is used for supplying power, the second diode D2 is turned on in the forward direction according to the second power supply voltage provided by the second power supply 90, and transmits the second power supply voltage to the same-name end of the first secondary winding N2 of the transformer TX 1.

It should be noted that the second isolation module 20 may be replaced by another module that performs its function, and is not limited thereto.

As shown in fig. 7, the first rectifying and filtering module 50 includes a third diode D3 and a third capacitor C3. The positive pole of the third diode D3 is electrically connected to the synonym end of the second secondary winding N3 of the transformer TX1, the negative pole of the third diode D3 is electrically connected to the first end of the third capacitor C3, the first switch module 30 and the second switch module 40, respectively, and the second end of the third capacitor C3 and the synonym end of the second secondary winding N3 of the transformer TX1 are electrically connected to the first power supply. Specifically, the third diode D3 is used for rectifying, and the third capacitor C3 is used for filtering and storing energy, so that the output target voltage Vout is more stable.

Note that, the first rectifying and filtering module 50 may be replaced by another module that performs its function, and is not limited thereto.

As shown in fig. 7, the second rectifying and filtering module 60 includes a fourth diode D4 and a fourth capacitor C4. The positive pole of the fourth diode D4 is electrically connected to the synonym end of the third secondary winding N4 of the transformer TX1, the negative pole of the fourth diode D4 is electrically connected to the first end of the fourth capacitor C4 and the second switch module 40, and the second end of the fourth capacitor C4 and the synonym end of the third secondary winding N4 of the transformer TX1 are electrically connected to the second power supply. Specifically, the fourth diode D4 is used for rectifying, and the fourth capacitor C4 is used for filtering and storing energy and outputting the third voltage to the second switch module 40.

It should be noted that the second rectifying and filtering module 60 may be replaced by another module that performs its function, and is not limited thereto.

As shown in fig. 4, the first switching module 30 includes a first PWM control unit 301, a first switching unit 302, a first feedback unit 303, a starting unit 304, a first detecting unit 305, and a second detecting unit 306. The first PMW control unit 301 is electrically connected to the starting unit 304, the first switching unit 302, the first feedback unit 303, the first detecting unit 305, and the second detecting unit 306, where the starting unit 304 is electrically connected to the first isolation module 10, the first power supply 80, the first detecting unit 305, the first feedback unit 303, the first rectifying and filtering module 50, and the second switching module 40, and the second detecting unit 306 is electrically connected to the second isolation module 20, the second power supply 90, and the voltage dividing module 70, and the first switching unit 302 is electrically connected to a synonym end of the primary winding N1 of the transformer TX 1. As can be seen from fig. 7, the starting unit 304 is electrically connected to the positive electrode of the first power supply 80, the positive electrode of the first diode D1, the first feedback unit 303, the negative electrode of the third diode D3, the first end of the third capacitor C3, and the second switch module 40, respectively. The starting unit 304 is electrically connected to the power supply terminal of the first PWM control unit 301, and the first feedback unit 303, the first detecting unit 305, and the second detecting unit 306 are electrically connected to the feedback terminal of the first PWM control unit 301.

Specifically, when only the first power supply 80 is used for supplying power, the starting unit 304 is turned on according to the first power supply voltage provided by the first power supply 80, and outputs a starting voltage to the first PWM control unit 301, the first PWM control unit 301 starts working according to the starting voltage, and outputs a first PWM control signal to the first switching unit 302, and the first switching unit 302 is turned on or off periodically according to the first PWM control signal, so that the primary winding N1 of the transformer TX1 stores energy or releases energy periodically, and finally, the target voltage is output through the second secondary winding N3 of the transformer TX1 and the first rectifying and filtering module 50. When the starting unit 304 receives the target voltage, the starting unit 304 is turned off and transmits the target voltage to the first PWM control unit 301, and the first PWM control unit 301 at this time is supplied with the target voltage. The first feedback unit 303 outputs a first feedback signal to the first PWM control unit 301 according to the target voltage, and the first PWM control unit 301 adjusts the first PWM control signal according to the first feedback signal, thereby adjusting the on time of the first switch unit 302, and finally maintaining the target voltage stable. The first detecting unit 305 is configured to detect whether the first power supply 80 is at a low voltage or an under voltage according to a first power supply voltage provided by the first power supply 80, and when the first power supply 80 is at the low voltage or the under voltage, the first detecting unit 305 pulls down the feedback end of the first PWM control unit 301 to the ground, so that the first PWM control unit 301 stops working.

When the first power supply 80 and the second power supply 90 are used for supplying power at the same time, the first power supply 80 is used for waking up the auxiliary power supply circuit, and the starting unit 304, the first PWM control unit 301, the first switching unit 302, the first feedback unit 303, and the first detection unit 305 are referred to the above working principle when only the first power supply 80 is used for supplying power. The second detecting unit 306 is configured to receive a second power voltage provided by the second power supply 90, and when the second power voltage reaches a preset voltage, the second detecting unit 306 pulls down the feedback end of the first PWM control unit 301 to ground, so that the first PWM control unit 301 stops working, i.e. the first switch module 30 is turned off, and the first power supply 80 is not used for supplying power. At this time, power is supplied by the second power supply 90.

When only the second power supply 90 is used for supplying power, the second detecting unit 306 receives the second power supply voltage, and the second power supply voltage has reached the preset voltage, and then the second detecting unit 306 pulls down the feedback end of the first PWM control unit 301 to the ground, so that the first PWM control unit 301 stops working, i.e. the first switch module 30 is turned off. Or the first detecting unit 305 determines whether the first power supply 80 is at a low voltage or an under voltage according to the first power supply voltage, when the first power supply 80 is at a low voltage or an under voltage, the first detecting unit 305 pulls down the feedback end of the first PWM control unit 301 to the ground, so that the first PWM control unit 301 stops working, that is, the first switch module 30 is turned off.

For example, the first PWM control unit 301 may be constructed by using a hardware circuit, so that the first PWM control unit 301 can output the first PWM signal according to the first feedback signal. The first feedback unit 303, the first detecting unit 305, and the second detecting unit 306 are all implemented by using the prior art, and the present application is not limited to the structures thereof.

Note that the first switch module 30 may be replaced by another module that performs its function, and is not limited thereto.

As shown in fig. 7, the first switching unit 302 includes a first switching tube Q1, a first resistor R1, a second resistor R2, and a first capacitor C1. The control end of the first switching tube Q1 is electrically connected with the first PWM control unit 301, the second conducting end of the first switching tube Q1 is electrically connected with the synonym end of the primary winding N1 of the transformer TX1, the first conducting end of the first switching tube Q1 is electrically connected with the first end of the first resistor R1 and the first end of the second resistor R2, the second end of the second resistor R2 and the first end of the first capacitor C1 are electrically connected with the first PWM control unit 301, and the second end of the first capacitor C1 and the second end of the first resistor R1 are electrically connected with the first power supply. The control end of the first switching tube Q1 is electrically connected to the control end of the first PWM control unit 301, and the second end of the second resistor R2 and the first end of the first capacitor C1 are both electrically connected to the sampling end of the first PWM control unit 301.

Specifically, when the first power supply 80 is used for supplying power or the first power supply 80 is used for waking up the auxiliary power supply circuit, the first switching tube Q1 is periodically turned on or off according to the first PWM control signal output by the first PWM control unit 301, so that the primary winding N1 of the transformer TX1 periodically stores energy or releases energy, and finally, the target voltage Vout is maintained stable through the coupling action of the second secondary winding N3 of the transformer TX1 and the rectifying and filtering action of the first rectifying and filtering module 50. The first resistor R1 and the second resistor R2 are current sampling resistors, and when the current is too large, the first PWM control unit 301 stops working. The first capacitor C1 is used for filtering.

The first switching tube Q1 is a PMOS (positive channel Metal Oxide Semiconductor ) tube, the control end of the first switching tube Q1 is a gate of the PMOS tube, the first conducting end of the first switching tube Q1 is a drain of the PMOS tube, and the second conducting end of the first switching tube Q1 is a source of the PMOS tube.

Note that the first switching unit 302 may be replaced with another unit that realizes the function thereof, and is not limited thereto.

As shown in fig. 5, the second switching module 40 includes a second PWM control unit 401, a second switching unit 402, a third switching unit 403, and a second feedback unit 404. The second PWM control unit 401 is electrically connected to the second switching unit 402, the third switching unit 403 and the second feedback unit 404, the second switching unit 402 is electrically connected to the heteronymous end of the first secondary winding N2 of the transformer TX1, the third switching unit 403 is electrically connected to the second rectifying and filtering module 60 and the voltage dividing module 70, and the second feedback unit 404 is electrically connected to the first rectifying and filtering module 50 and the first switching module 30. As can be seen from fig. 5, the second feedback unit 404 is electrically connected to the first rectifying and filtering module 50, the first feedback unit 303 and the starting unit 304, respectively. As can be seen from fig. 7, the second feedback unit 404 is electrically connected to the cathode of the third diode D3, the first end of the third capacitor C3, the first feedback unit 303, and the start-up unit 304, respectively. The third switching unit 403 is electrically connected to the power supply terminal of the second PWM control unit 401, and the second feedback unit 404 is electrically connected to the feedback terminal of the second PWM control unit 401.

Specifically, when the first power source 80 is used for supplying power, the voltage dividing module 70 outputs the first voltage to the third switching unit 403, the first voltage is a low level signal, and the third switching unit 403 is turned off according to the first voltage, so that the second PWM control unit 401 cannot be supplied with power, that is, the second switching module 40 is turned off.

When the first power supply 80 and the second power supply 90 are used for supplying power at the same time, the first power supply 80 is used for waking up the auxiliary power supply circuit, the voltage dividing module 70 outputs a first voltage to the third switch unit 403, the first voltage is a low level voltage, and the third switch unit 403 is turned off according to the first voltage, so that the second PWM control unit 401 cannot be supplied with power, that is, the second switch module 40 is turned off. When the second power voltage provided by the second power supply 90 reaches the preset voltage, the first switch module 30 is turned off, i.e. the first power supply 80 is not used for supplying power, and the second power supply 90 is used for supplying power. The voltage dividing module 70 outputs a second voltage to the third switching unit 403 according to the second power voltage, the second voltage is a high level voltage, the second rectifying and filtering module 60 outputs a third voltage to the third switching unit 403, the third switching unit 403 is turned on according to the second voltage and transmits the third voltage to the second PWM control unit 401, the second PWM control unit 401 is turned on according to the third voltage and outputs a second PWM control signal to the second switching unit 402, the second switching unit 402 is turned on or off periodically according to the second PWM control signal, the first secondary winding N2 of the transformer TX1 is made to store or release energy periodically, and the target voltage is output through the second secondary winding N3 of the transformer TX1 and the first rectifying and filtering module 50. The second feedback unit 404 outputs a second feedback signal to the second PWM control unit 401 according to the target voltage, and the second PWM control unit 401 adjusts the second PWM control signal according to the second feedback signal, thereby adjusting the on time of the second switching unit 402, and finally maintaining the target voltage stable.

When only the second power supply 90 is used for supplying power, the second PWM control unit 401, the second switching unit 402, the third switching unit 403, and the second feedback unit 404 are referred to the operating principle when the first power supply 80 and the second power supply 90 are used for supplying power at the same time.

For example, the second PWM control unit 401 may be constructed by using a hardware circuit, so that the second PWM control unit 401 can output the second PWM signal according to the second feedback signal. The second feedback unit 404 is implemented using the prior art, and the present application is not limited to its structure.

Note that the second switch module 40 may be replaced by another module that performs its function, and is not limited thereto.

As shown in fig. 7, the second switching unit 402 includes a second switching tube Q2, a third resistor R3, a fourth resistor R4, and a second capacitor C2. The control end of the second switching tube Q2 is electrically connected with the second PWM control unit 401, the second conducting end of the second switching tube Q2 is electrically connected with the synonym end of the first secondary winding N2 of the transformer TX1, the first conducting end of the second switching tube Q2 is respectively electrically connected with the first end of the third resistor R3 and the first end of the fourth resistor R4, the second end of the fourth resistor R4 and the first end of the second capacitor C2 are electrically connected with the second PWM control unit 401, and the second end of the third resistor R3 and the second end of the second capacitor C2 are electrically connected with a second power supply. The control end of the second switching tube Q2 is electrically connected to the control end of the second PWM control unit 401, and the second end of the fourth resistor R4 and the first end of the second capacitor C2 are both electrically connected to the sampling end of the second PWM control unit 401.

Specifically, when the first power supply 80 and the second power supply 90 are used for supplying power at the same time, and the auxiliary power supply circuit is completely awakened or only the second power supply 90 is used for supplying power, the second switching tube Q2 is periodically turned on or off according to the second PWM control signal output by the second PWM control unit 401, so that the first secondary winding N2 of the transformer TX1 periodically stores energy or releases energy, and finally, the target voltage Vout is maintained stable through the coupling action of the second secondary winding N3 of the transformer TX1 and the rectifying and filtering action of the first rectifying and filtering module 50. Wherein, the third resistor R3 and the fourth resistor R4 are current sampling resistors, and when the current is too large, the second PWM control unit 401 stops working. The second capacitor C2 is used for filtering.

The second switching tube Q2 is a PMOS tube, the control end of the second switching tube Q2 is a gate of the PMOS tube, the first conducting end of the second switching tube Q2 is a drain of the PMOS tube, and the second conducting end of the second switching tube Q2 is a source of the PMOS tube.

Note that the second switching unit 402 may be replaced with another unit that realizes the function thereof, and is not limited thereto.

As shown in fig. 7, the third switching unit 403 includes a third switching transistor Q3. The control end of the third switching tube Q3 is electrically connected to the voltage dividing module 70, the first conducting end of the third switching tube Q3 is electrically connected to the second rectifying and filtering module 60, and the second conducting end of the third switching tube Q3 is electrically connected to the second PWM control unit 401. As can be seen from fig. 7, the first conducting end of the third switching tube Q3 is electrically connected to the cathode of the fourth diode D4 and the first end of the fourth capacitor C4, respectively.

Specifically, when the first power supply 80 is used for supplying power, the voltage dividing module 70 outputs the first voltage to the third switching tube Q3, the first voltage is a low level voltage, and the third switching tube Q3 is turned off according to the first voltage, so that the second PWM control unit 401 cannot be supplied with power, that is, the second switching module 40 is turned off.

When the first power supply 80 and the second power supply 90 are used for supplying power at the same time, the first power supply 80 is used for waking up the auxiliary power supply circuit, the voltage dividing module 70 outputs a first voltage to the control end of the third switching tube Q3, the first voltage is a low level voltage, the third switching tube Q3 is turned off according to the first voltage, and then the second PWM control unit 401 cannot be supplied with power, that is, the second switching module 40 is turned off. When the second power voltage provided by the second power supply 90 reaches the preset voltage, the first switch module 30 is turned off, i.e. the first power supply 80 is not used for supplying power, and the second power supply 90 is used for supplying power. The voltage dividing module 70 outputs a second voltage to the control end of the third switching tube Q3 according to the second power voltage, the second voltage is a high level voltage, the second rectifying and filtering module 60 outputs a third voltage to the first conducting end of the third switching tube Q3, the third switching tube Q3 is conducted according to the second voltage, the third voltage is transmitted to the second PWM control unit 401, and the second PWM control unit 401 starts working according to the third voltage.

When only the second power supply 90 is used for supplying power, the voltage dividing module 70 outputs a second voltage to the control end of the third switching tube Q3 according to the second power supply voltage, the second voltage is a high level voltage, the second rectifying and filtering module 60 outputs a third voltage to the first conducting end of the third switching tube Q3, the third switching tube Q3 is conducted according to the second voltage, and the third voltage is transmitted to the second PWM control unit 401, and the second PWM control unit 401 starts working according to the third voltage.

The third switching tube Q3 is an NMOS (n-metal-oxide-semiconductor) tube, the control end of the third switching tube Q3 is a gate of the NMOS tube, the first conducting end of the third switching tube Q3 is a drain of the NMOS tube, and the second conducting end of the third switching tube Q3 is a source of the NMOS tube.

Note that the third switching unit 403 may be replaced with another unit that realizes the function thereof, and is not limited thereto.

As shown in fig. 7, the voltage dividing module 70 includes a fifth resistor R5 and a sixth resistor R6. The first end of the fifth resistor R5 is electrically connected to the second power supply 90, the second isolation module 20 and the first switch module 30, respectively, the second end of the fifth resistor R5 is electrically connected to the first end of the sixth resistor R6 and the second switch module 40, respectively, and the second end of the sixth resistor R6 is electrically connected to the second power supply. As can be seen from fig. 7, the first end of the fifth resistor R5 is electrically connected to the positive electrode of the second power supply 90, the positive electrode of the second diode D2 and the second detection unit 306, and the negative electrode of the second power supply 90 is electrically connected to the second power supply.

Specifically, when only the first power source 80 is used to supply power, there is no voltage on the second power source 90, that is, there is no voltage on the fifth resistor R5 and the sixth resistor R6, and the first voltage output from the voltage dividing module 70 to the third switching unit 403 is 0V.

When the first power supply 80 and the second power supply 90 are used for supplying power simultaneously, the first power supply 80 is used for waking up the auxiliary power supply circuit, and at this time, the resistor R5 and the sixth resistor R6 are also not provided with voltages, so that the voltage division module 70 outputs the first voltage to the third switch unit 403 as 0V. When the second power voltage provided by the second power supply 90 reaches the preset voltage, the first switch module 30 is turned off, i.e. the first power supply 80 is not used for supplying power, and the second power supply 90 is used for supplying power. The fifth resistor R5 and the sixth resistor R6 output a second voltage to the third switching unit 403 according to the second power supply voltage, the second voltage being a high level voltage.

When power is supplied only with the second power supply 90, the fifth resistor R5 and the sixth resistor R6 output a second voltage to the third switching unit 403 according to the second power supply voltage, the second voltage being a high level voltage.

It should be noted that the voltage dividing module 70 may be replaced by another module that performs its function, and is not limited thereto.

As shown in fig. 6, the auxiliary power supply circuit further includes a filtering module 100. The filtering module 100 is electrically connected to the second isolation module 20, the second power supply 90, the voltage dividing module 70, and the first switching module 30, respectively. The filtering module 100 is configured to filter the second power supply voltage provided by the second power supply 90.

As shown in fig. 7, the filter module 100 includes a fifth capacitor C5. The first end of the fifth capacitor C5 is electrically connected to the positive electrode of the second diode D2, the positive electrode of the second power supply 90, the first end of the fifth resistor R5, and the second detection unit 306, and the second end of the fifth capacitor C5 and the negative electrode of the second power supply 90 are electrically connected to the second power supply.

The embodiment of the application also provides an auxiliary power supply device which comprises the auxiliary power supply circuit. Because the auxiliary power supply device comprises the auxiliary power supply circuit, the circuit structure of the auxiliary power supply device provided by the embodiment of the application is realized by adopting only one transformer, and the auxiliary power supply device has the advantages of small volume and low cost.

The embodiment of the application also provides an energy storage inverter which comprises the auxiliary power supply device. The energy storage inverter provided by the embodiment of the application has the advantages of small volume and low cost. The specific working principle is referred to the description of the working principle of the auxiliary power supply device, and will not be repeated here.

In the foregoing embodiments, the descriptions of the embodiments are emphasized, and in part, not described or illustrated in any particular embodiment, reference is made to the related descriptions of other embodiments.

The above embodiments are only for illustrating the technical solution of the present application, and not for limiting the same; although the application has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit and scope of the technical solutions of the embodiments of the present application, and are intended to be included in the scope of the present application.

Claims

1. The auxiliary power supply circuit is characterized by comprising a transformer, a first isolation module, a second isolation module, a first switch module, a second switch module, a first rectifying and filtering module, a second rectifying and filtering module and a voltage dividing module; the first isolation module is electrically connected with the homonymous end of the primary winding of the transformer, the first switch module and the first power supply respectively, the first switch module is electrically connected with the homonymous end of the primary winding of the transformer, the second switch module, the first rectifying and filtering module, the second isolation module, the voltage dividing module and the second power supply respectively, the homonymous end of the first secondary winding of the transformer is electrically connected with the second isolation module, the second switch module is electrically connected with the homonymous end of the first secondary winding of the transformer, the voltage dividing module and the second rectifying and filtering module respectively, the homonymous end and the homonymous end of the second secondary winding of the transformer are electrically connected with the first rectifying and filtering module respectively, and the homonymous end of the third secondary winding of the transformer are electrically connected with the second rectifying and filtering module respectively;

2. The auxiliary power circuit of claim 1, wherein the first switching module comprises a first PWM control unit, a first switching unit, a first feedback unit, a starting unit, a first detection unit, and a second detection unit; the first PWM control unit is respectively and electrically connected with the starting unit, the first switching unit, the first feedback unit, the first detection unit and the second detection unit, the starting unit is respectively and electrically connected with the first isolation module, the first power supply, the first detection unit, the first feedback unit, the first rectifying and filtering module and the second switching module, the second detection unit is respectively and electrically connected with the second isolation module, the second power supply and the voltage dividing module, and the first switching unit is electrically connected with a synonym end of a primary winding of the transformer;

3. The auxiliary power circuit of claim 2, wherein the first switching unit comprises a first switching tube, a first resistor, a second resistor, and a first capacitor; the control end of the first switching tube is electrically connected with the first PWM control unit, the second conducting end of the first switching tube is electrically connected with the synonym end of the primary winding of the transformer, the first conducting end of the first switching tube is electrically connected with the first end of the first resistor and the first end of the second resistor respectively, the second end of the second resistor and the first end of the first capacitor are electrically connected with the first PWM control unit, and the second end of the first capacitor and the second end of the first resistor are electrically connected with a first power supply.

4. The auxiliary power circuit of claim 1, wherein the second switching module comprises a second PWM control unit, a second switching unit, a third switching unit, and a second feedback unit; the second PWM control unit is respectively and electrically connected with the second switch unit, the third switch unit and the second feedback unit, the second switch unit is electrically connected with the synonym end of the first secondary winding of the transformer, the third switch unit is respectively and electrically connected with the second rectifying and filtering module and the voltage dividing module, and the second feedback unit is respectively and electrically connected with the first rectifying and filtering module and the first switch module;

5. The auxiliary power circuit of claim 4 wherein the second switching unit comprises a second switching tube, a third resistor, a fourth resistor, and a second capacitor; the control end of the second switching tube is electrically connected with the second PWM control unit, the second conducting end of the second switching tube is electrically connected with the synonym end of the first secondary winding of the transformer, the first conducting end of the second switching tube is electrically connected with the first end of the third resistor and the first end of the fourth resistor respectively, the second end of the fourth resistor and the first end of the second capacitor are electrically connected with the second PWM control unit, and the second end of the third resistor and the second end of the second capacitor are electrically connected with a second power supply.

6. The auxiliary power circuit of claim 4 wherein the third switching unit comprises a third switching tube; the control end of the third switching tube is electrically connected with the voltage dividing module, the first conducting end of the third switching tube is electrically connected with the second rectifying and filtering module, and the second conducting end of the third switching tube is electrically connected with the second PWM control unit.

7. The auxiliary power circuit of claim 1, wherein the voltage divider module comprises a fifth resistor and a sixth resistor; the first end of the fifth resistor is electrically connected with the second power supply, the second isolation module and the first switch module respectively, the second end of the fifth resistor is electrically connected with the first end of the sixth resistor and the second switch module respectively, and the second end of the sixth resistor is electrically connected with the second power supply.

8. The auxiliary power circuit of any of claims 1-7, further comprising a filtering module; the filtering module is electrically connected with the second isolation module, the second power supply, the voltage division module and the first switch module respectively.

9. An auxiliary power supply comprising an auxiliary power supply circuit as claimed in any one of claims 1 to 8.

10. An energy storage inverter comprising the auxiliary power unit of claim 9.