CN219458675U - Power supply device and power supply system - Google Patents

Abstract

The application provides power supply equipment and a power supply system, wherein the power supply equipment comprises a power supply circuit, a switch circuit, a control circuit and a voltage conversion circuit, and the power supply circuit is used for outputting alternating current signals; the switching circuit comprises a first switch and a second switch, the first switch is connected with an alternating current output interface of the power supply equipment, and the second switch is connected with a direct current output interface of the power supply equipment; the control circuit is used for detecting the closing states of the first switch and the second switch and outputting a first control signal or a second control signal; the voltage conversion circuit is used for carrying out step-down processing on the alternating current signal according to the first control signal and outputting the alternating current signal to the alternating current output interface, and is also used for carrying out rectification processing on the alternating current signal according to the second control signal and outputting the direct current signal to the direct current output interface. Therefore, different types of power supplies can be output according to the needs of the user, and the actual power consumption needs of the user are met.

Description

Power supply device and power supply system

Technical Field

The application relates to the field of electronic power, in particular to power supply equipment and a power supply system.

Background

For existing power generation equipment such as oil-driven generators (fuel oil, fuel oil generators) and the like, generally, only a single type of output is needed, namely, the existing power generation equipment can only output alternating current or direct current, has poor applicability and cannot meet the requirements of users on using different types of power sources. Therefore, the existing power generation equipment cannot output different types of power sources according to the needs of users, and cannot meet the actual power consumption needs of the users.

Disclosure of Invention

The main aim of the application is to provide power supply equipment and a power supply system, which aim at outputting different types of power sources according to the needs of users so as to meet the actual power consumption needs of the users.

In a first aspect, the present application provides a power supply apparatus including a power supply circuit for outputting an ac signal, a switching circuit, a control circuit, and a voltage conversion circuit; the switching circuit comprises a first switch and a second switch, the first switch is connected with an alternating current output interface of the power supply equipment, and the second switch is connected with a direct current output interface of the power supply equipment; the control circuit is connected with the switch circuit and is used for detecting the closing states of the first switch and the second switch and outputting a first control signal according to the closing state of the first switch or outputting a second control signal according to the closing state of the second switch; the voltage conversion circuit is connected with the power supply circuit, the control circuit and the switch circuit, and is used for carrying out voltage reduction processing on the alternating current signal according to the first control signal when receiving the first control signal, outputting an alternating current signal to the alternating current output interface through the first switch, rectifying processing on the alternating current signal according to the second control signal when receiving the second control signal, and outputting a direct current signal to the direct current output interface through the second switch.

In an embodiment, the power supply device further comprises a filter circuit; the filter circuit is respectively connected with the voltage conversion circuit and the switch circuit, and is used for filtering the electric signal output by the voltage conversion circuit and outputting the electric signal to the switch circuit.

In an embodiment, the voltage conversion circuit includes a full-bridge unit and a filtering unit, the full-bridge unit is connected with the power supply circuit, the full-bridge unit includes a first bridge arm formed by connecting a first upper switching tube and a first lower switching tube in series, and a second bridge arm formed by connecting a second upper switching tube and a second lower switching tube in series, the full-bridge unit is configured to, under the control of the first control signal, make the first upper switching tube and the second lower switching tube conduct, and turn the first lower switching tube and the second upper switching tube off, or make the second upper switching tube and the first lower switching tube conduct, and the second lower switching tube and the first upper switching tube turn the first switching tube off, so as to output the ac signal, and is further configured to, under the control of the second control signal, make each switching tube on the full-bridge unit alternately conduct or turn the second switching tube off so as to rectify the ac signal output by the power supply circuit, and output the dc signal; the filtering unit is connected with the full-bridge unit and the switch circuit, and is used for performing first step-down filtering processing on the alternating current signal when the first control signal is received, and performing second step-down filtering processing on the direct current signal when the second control signal is received.

In an embodiment, the filtering unit includes a first inductor, a first capacitor, a second capacitor, and a third switch: the first end of the first inductor is connected with the bridge arm midpoint of the first bridge arm, and the second end of the first inductor is connected with the switch circuit; the first end of the first capacitor is connected with the second end of the first inductor, and the second end of the first capacitor is connected with the bridge arm midpoint of the second bridge arm; the third switch is connected in series with the second capacitor and then connected in parallel with the first capacitor; the third switch is opened when the first control signal is received and closed when the second control signal is received.

In an embodiment, the capacitance of the second capacitor is greater than the capacitance of the first capacitor.

In an embodiment, the third switch is a relay.

In an embodiment, the filter circuit includes a common mode inductance and a third capacitance; the first end of the common-mode inductor is connected with the voltage conversion circuit, and the second end of the common-mode inductor is connected with the switching circuit; the third capacitor is connected in parallel between the second ends of the common mode inductors.

In one embodiment, the power supply circuit includes an oil-powered alternator.

In one embodiment, the power supply circuit includes a dual fuel alternator.

In a second aspect, the present application provides a power supply system comprising a power supply apparatus as described above.

The embodiment of the application provides power supply equipment and a power supply system. The power supply equipment comprises a power supply circuit, a switch circuit, a control circuit and a voltage conversion circuit, wherein the first control signal or the second control signal is output by detecting the closing states of a first switch and a second switch in the switch circuit, so that the voltage conversion circuit can step down an alternating current signal output by the power supply circuit when receiving the first control signal, and output the alternating current signal to an alternating current output interface through the first switch, and can rectify the alternating current signal output by the power supply circuit according to the second control signal and output a direct current signal to the direct current output interface through the second switch when receiving the second control signal. According to the embodiment of the application, different types of power sources can be output according to the needs of the user, so that the actual power consumption needs of the user are met.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed in the description of the embodiments will be briefly introduced below, and it is obvious that the drawings in the following description are some embodiments of the present application, and 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 power supply device according to an embodiment of the present application;

FIG. 2 is a schematic block diagram of a filter circuit according to an embodiment of the present disclosure;

FIG. 3 is a schematic circuit diagram of a voltage converting circuit according to an embodiment of the present disclosure;

FIG. 4 is a schematic circuit diagram of a filtering unit according to an embodiment of the present disclosure;

FIG. 5 is a schematic diagram of a filtering circuit according to an embodiment of the present disclosure;

fig. 6 is a schematic block diagram of a power supply system according to an embodiment of the present application.

Detailed Description

The following description of the embodiments of the present application will be made clearly and fully with reference to the accompanying drawings, in which it is evident that the embodiments described are some, but not all, of the embodiments of the present application. All other embodiments, which can be made by one of ordinary skill in the art without undue burden from the present disclosure, are within the scope of the present disclosure.

Some embodiments of the present application are described in detail below with reference to the accompanying drawings. The following embodiments and features of the embodiments may be combined with each other without conflict.

Referring to fig. 1, fig. 1 is a schematic block circuit diagram of an implementation of a power supply apparatus 100 according to an embodiment of the present application. As shown in fig. 1, the power supply apparatus 100 includes a power supply circuit 10, a switching circuit 20, a control circuit 30, and a voltage conversion circuit 40, the power supply circuit 10 being configured to output an alternating current signal and to output the alternating current signal to the voltage conversion circuit 40. The switching circuit 20 includes a first switch S1 and a second switch S2, the first switch S1 is connected to the ac output interface 50 of the power supply apparatus 100, specifically, when the first switch S1 is closed, a path in which the first switch S1 is located is connected to the ac output interface 50 of the power supply apparatus 100, and when the first switch S1 is opened, a path in which the first switch S1 is located is disconnected from the ac output interface 50 of the power supply apparatus 100. The second switch S2 is connected to the dc output interface 60 of the power supply apparatus 100, specifically, when the second switch S2 is closed, a path in which the second switch S2 is located is connected to the dc output interface 60 of the power supply apparatus 100, and when the second switch S2 is opened, a path in which the second switch S2 is located is disconnected from the dc output interface 60 of the power supply apparatus 100.

The control circuit 30 is connected to the switch circuit 20, specifically, the control circuit 30 is connected to the first switch S1 and the second switch S2, and the control circuit 30 is configured to detect the closed states of the first switch S1 and the second switch S2, and output a first control signal according to the closed state of the first switch S1, or output a second control signal according to the closed state of the second switch S2.

The first switch S1 may be a relay, and may also be an electronic element for executing a switching function, such as a switching tube, a triode, an optocoupler, and the like.

For example, the user may control the closed states of the first switch S1 and the second switch S2, for example, the user may control the first switch S1 to be closed, the second switch S2 to be opened, where the path where the first switch S1 is located is connected to the ac output interface 50 of the power supply apparatus 100, the path where the second switch S2 is located is disconnected from the dc output interface 60 of the power supply apparatus 100, where the control circuit 30 detects that the closed state of the first switch S1 is closed, and the closed state of the second switch S2 is opened, so that the control circuit 30 outputs the first control signal.

The voltage conversion circuit 40 is connected to the power supply circuit 10, the control circuit 30, and the switch circuit 20, and the voltage conversion circuit 40 is configured to, when receiving a first control signal, step down the ac signal according to the first control signal, output an ac electrical signal to the ac output interface 50 through the first switch S1, and, when receiving a second control signal, rectify the ac signal according to the second control signal, and output a dc electrical signal to the dc output interface 60 through the second switch S2.

When the voltage conversion circuit 40 receives the first control signal, it indicates that the closed state of the first switch S1 is closed, and at this time, the first control signal is a step-down control signal, and the voltage conversion circuit 40 performs a step-down process on the ac signal output by the power supply circuit 10 according to the step-down control signal, and outputs an ac electrical signal to the ac output interface 50 through the first switch S1. When the voltage conversion circuit 40 receives the second control signal, it indicates that the second switch S2 is closed, and at this time, the first control signal is a rectification control signal, and the voltage conversion circuit 40 rectifies the ac signal output by the power supply circuit 10 according to the rectification control signal, and outputs a dc signal to the dc output interface 60 through the second switch S2.

The embodiment of the application provides a power supply device 100. The power supply apparatus 100 outputs a first control signal or a second control signal by detecting the closed states of the first switch S1 and the second switch S2, so that the voltage conversion circuit 40 performs a step-down process on the ac signal and outputs an ac signal to the ac output interface 50 through the first switch S1 when receiving the first control signal, performs a rectification process on the ac signal according to the second control signal when receiving the second control signal, and outputs a dc signal to the dc output interface 60 through the second switch S2. Therefore, different types of power supplies can be output according to the needs of the user, and the actual power consumption needs of the user are met.

Fig. 2 is a power supply apparatus 100 according to an embodiment of the present application. The power supply apparatus 100 further includes a filter circuit 70, where the filter circuit 70 is connected to the voltage conversion circuit 40 and the switch circuit 20, and the filter circuit 70 is configured to filter an electrical signal output by the voltage conversion circuit 40 and output the filtered electrical signal to the switch circuit 20. The filter circuit 70 can filter electromagnetic interference existing in the electric signal output from the voltage conversion circuit 40 and output the filtered electromagnetic interference to the switching circuit 20.

Electromagnetic interference (Electromagnetic Interference, EMI) refers to interference phenomena generated by electromagnetic waves acting on electronic components, and includes both conducted interference and radiated interference. Conductive interference refers to coupling (interfering) signals on one electrical network to another electrical network through a conductive medium. The radiated interference means that an interference source couples (interferes) signals to another electric network through space, and a high-frequency signal wire, pins of an integrated circuit, various connectors and the like can become the radiated interference source with antenna characteristics, and can emit electromagnetic waves and influence normal operation of other systems or other subsystems in the system. Since electromagnetic interference may be generated between the circuits in the power supply apparatus 100, the present application adds the filter circuit 70 to eliminate electromagnetic interference existing in the electric signal output from the voltage conversion circuit 40.

Fig. 3 is a power supply apparatus 100 according to an embodiment of the present application. In the power supply apparatus 100, the voltage conversion circuit 40 includes a full-bridge unit 41 and a filter unit 42, and the full-bridge unit 41 includes a first leg formed by connecting a first upper switching tube 410 and a first lower switching tube 411 in series, and a second leg formed by connecting a second upper switching tube 412 and a second lower switching tube 413 in series.

The first upper switching tube 410, the first lower switching tube 411, the second upper switching tube 412, and the second lower switching tube 413 may be electronic components such as diodes, triodes, etc. that can be turned on or off.

The full-bridge unit 41 is configured to turn on the first upper switching tube 410 and the second lower switching tube 413, turn off the first lower switching tube 411 and the second upper switching tube 412, or turn on the second upper switching tube 412 and the first lower switching tube 411, and turn off the second lower switching tube 413 and the first upper switching tube 410 under the control of the first control signal, so as to output the ac signal.

The filtering unit 42 is connected to the full-bridge unit 41 and the switching circuit 20, and the filtering unit 42 is configured to perform a first step-down filtering process on the ac electrical signal when receiving the first control signal, and perform a second step-down filtering process on the dc electrical signal when receiving the second control signal. The first step-down filtering process and the second step-down filtering process are both LC filtering processes, specifically, the first step-down filtering process is a step-down filtering process for an ac signal, and the second step-down filtering process is a step-down filtering process for a dc signal.

Specifically, the full-bridge unit 41 is connected to the power supply circuit 10 and the control circuit 30, and if the control circuit 30 outputs the first control signal at this time, that is, the first switch S1 is closed, it indicates that the user wants the power supply apparatus 100 to output the ac electric signal. At this time, the full-bridge unit 41 may be controlled by the first control signal to turn on the first upper switching tube 410 and the second lower switching tube 413, and turn off the first lower switching tube 411 and the second upper switching tube 412, where the first upper switching tube 410, the second lower switching tube 413, and the filtering unit 42 form a buck circuit, so as to perform a first step-down filtering process on the ac signal, and output an ac electrical signal to the ac output interface 50 through the first switch S1. The full-bridge unit 41 may further turn on the second upper switching tube 412 and the first lower switching tube 411 under the control of the first control signal, and turn off the second lower switching tube 413 and the first upper switching tube 410, where the second upper switching tube 412, the first lower switching tube 411, and the filtering unit 42 form a buck circuit, so as to perform a first step-down filtering process on the ac signal, and output an ac electrical signal to the ac output interface 50 through the first switch S1.

Specifically, the full-bridge unit 41 is connected to the power supply circuit 10 and the control circuit 30, and if the control circuit 30 outputs the second control signal at this time, that is, the second switch S2 is closed, it indicates that the user wants the power supply apparatus 100 to output the dc signal. At this time, under the control of the first control signal, when the power supply circuit 10 outputs an ac signal with a positive half cycle, the first upper switching tube 410 and the second lower switching tube 413 are turned on, and the first lower switching tube 411 and the second upper switching tube 412 are turned off, thereby forming a half-wave rectified voltage with positive upper and negative lower. When the power supply circuit 10 outputs an ac signal of a negative half cycle, the second upper switching tube 412 and the first lower switching tube 411 are turned on, and the second lower switching tube 413 and the first upper switching tube 410 are turned off, so that a rectified voltage of another half wave, positive upper and negative lower, is formed. The above steps are repeated to rectify the ac signal and perform the second step-down filtering process, and output the dc signal to the dc output interface 60 through the second switch S2.

Fig. 4 is a schematic diagram of a power supply apparatus 100 according to an embodiment of the present application. In the power supply apparatus 100, the filtering unit 42 includes a first inductance L1, a first capacitance C1, a second capacitance C2, and a third switch S3: a first end of the first inductor L1 is connected with a bridge arm midpoint of the first bridge arm, and a second end of the first inductor L1 is connected with the filter circuit 70; the first end of the first capacitor C1 is connected with the second end of the first inductor L1, and the second end of the first capacitor C1 is connected with the middle point of the bridge arm of the second bridge arm; the third switch S3 is connected in series with the second capacitor C2 and then connected in parallel with the first capacitor C1; the third switch S3 is opened when receiving the first control signal and closed when receiving the second control signal. Referring to fig. 4, the second terminal of the first capacitor C1 is also grounded (not shown). In fig. 4, when the power supply apparatus 100 does not include the filter circuit 70, the second end of the first inductor L1 is connected to the switch circuit 20.

The first inductor L1, the first capacitor C1, the second capacitor C2, and the third switch S3 may form a buck circuit with the full-bridge unit 41, so that when receiving the first control signal, the first buck filter process is performed on the ac electric signal, and when receiving the second control signal, the second buck filter process is performed on the dc electric signal.

Specifically, the second capacitor C2 and the third switch S3 form a filtering gating circuit, and since only a capacitor with a small capacitance is needed for filtering the ac signal, a capacitor with a relatively large capacitance is needed for filtering the dc signal. Therefore, when the control circuit 30 outputs the first control signal, that is, when the power supply apparatus 100 is required to output the ac electric signal, the control circuit 30 controls the third switch S3 to be turned off, and the ac electric signal is subjected to the filtering process only through the first capacitor C1. When the control circuit 30 outputs the second control signal, that is, when the power supply device 100 is required to output the dc signal, the control circuit 30 controls the third switch S3 to be closed, and the first capacitor C1 and the second capacitor C2 are connected in parallel, so as to increase the capacitance value of the corresponding capacitor, so that the dc signal is filtered through the first capacitor C1 and the second capacitor C2.

In some embodiments, the capacitance of the second capacitance C2 is greater than the capacitance of the first capacitance C1.

Since only a small capacitance is required for filtering the ac signal, and a relatively large capacitance is required for filtering the dc signal. Moreover, the first capacitor C1 is used for filtering the ac electric signal, so that the first capacitor C1 needs to use a capacitor with smaller capacitance, and the second capacitor C2 needs to use a capacitor with larger capacitance, so that the capacitance value of the first capacitor C1 and the second capacitor C2 after being connected in parallel becomes larger, and the requirement of filtering the dc electric signal is met.

In some embodiments, the third switch S3 may be a relay, and may also be an electronic component for performing a switching function, such as a switch tube, a triode, an optocoupler, or the like.

Fig. 5 is a schematic diagram of a power supply apparatus 100 according to an embodiment of the present application. In the power supply apparatus 100, the filter circuit 70 includes a common-mode inductance L2 and a third capacitance C3. The first end of the common-mode inductor L2 is connected to the voltage converting circuit 40, the second end of the common-mode inductor L2 is connected to the switching circuit 20, and the third capacitor C3 is connected in parallel between the second ends of the common-mode inductor L2. Thus, electromagnetic interference existing in the electric signal output from the voltage conversion circuit 40 can be filtered and output to the switching circuit 20.

Wherein, the common-mode inductance L2 and the third capacitor C3 play a role of EMI filtering the electric signal output by the voltage conversion circuit 40, for suppressing the electromagnetic wave generated by the high-speed signal line from radiating outwards. When normal current in the circuit flows through the common-mode inductor L2, the currents generate reverse magnetic fields in the inductor coils wound in the same phase to cancel each other, and at the moment, the normal signal current is mainly influenced by the coil resistance (and little damping caused by leakage inductance). When common mode current flows through the coil, due to the isotropy of the common mode current, a magnetic field in the same direction is generated in the coil to increase the inductance of the coil, so that the coil presents high impedance, a stronger damping effect is generated, and the common mode current is attenuated, thereby achieving the purpose of filtering.

Specifically, when the first switch S1 is closed, the electric signal output by the voltage conversion circuit 40 is filtered by the common-mode inductor L2 and the third capacitor C3, and then the ac electric signal is output to the ac output interface 50 through the first switch S1. When the second switch S2 is closed, the electric signal output by the voltage conversion circuit 40 is filtered by the common-mode inductor L2 and the third capacitor C3, and then the dc electric signal is output to the dc output interface 60 through the second switch S2.

In some embodiments, the power supply circuit 10 includes an oil-powered alternator.

Among them, the oil-driven alternator can generate electricity by diesel oil, thereby outputting an ac signal to the voltage conversion circuit 40.

In some embodiments, the power supply circuit 10 includes a dual fuel alternator.

The dual fuel alternator may use a mixture of diesel and natural gas as fuel, or may operate on diesel alone in the absence of natural gas. It has the outstanding and reliable performance of diesel engine set, and also has the economic and environmental protection advantages of natural gas set. When the load of the unit does not reach 30%, the unit is completely driven by diesel. When the load continues to increase, natural gas starts to be injected and mixed with diesel to burn, and as the load increases, the component of natural gas input correspondingly increases.

As shown in fig. 6, fig. 6 is a schematic block circuit diagram of an embodiment of a power supply system 1000 provided in an embodiment of the present application, where the power supply system 1000 includes a power supply device 100.

Wherein the power supply apparatus 100 may be set with reference to the examples of fig. 1 to 5, for example, the power supply apparatus 100 may include a power supply circuit 10, a switching circuit 20, a control circuit 30, and a voltage conversion circuit 40; the specific arrangement manner of the power supply device 100 may refer to the corresponding embodiments described in the present specification, and the description of the embodiment is omitted here. The power supply system 1000 provided by the embodiment of the application can output different types of power sources according to the needs of the user, so that the actual power consumption needs of the user are met.

In the description of the present application, it should be noted that, unless explicitly stated and limited otherwise, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected. Either mechanically or electrically. Can be directly connected or indirectly connected through an intermediate medium, and can be communicated with the inside of two elements or the interaction relationship of the two elements. The specific meaning of the terms in this application will be understood by those of ordinary skill in the art as the case may be.

In this application, unless expressly stated or limited otherwise, a first feature "above" or "below" a second feature may include both the first and second features being in direct contact, and may also include the first and second features not being in direct contact but being in contact with each other by way of additional features therebetween. Moreover, a first feature being "above," "over" and "on" a second feature includes the first feature being directly above and obliquely above the second feature, or simply indicating that the first feature is higher in level than the second feature. The first feature being "under", "below" and "beneath" the second feature includes the first feature being directly under and obliquely below the second feature, or simply means that the first feature is less level than the second feature.

The above disclosure provides many different embodiments or examples for implementing different structures of the present application. The components and arrangements of specific examples are described above in order to simplify the disclosure of this application. Of course, they are merely examples and are not intended to limit the present application. Furthermore, the present application may repeat reference numerals and/or letters in the various examples, which are for the purpose of brevity and clarity, and which do not in themselves indicate the relationship between the various embodiments and/or arrangements discussed. In addition, the present application provides examples of various specific processes and materials, but one of ordinary skill in the art may recognize the application of other processes and/or the use of other materials.

In the description of the present specification, reference to the terms "one embodiment," "some embodiments," "illustrative embodiments," "examples," "specific examples," or "some examples," etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present application. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiments or examples. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

The above embodiments are only preferred embodiments of the present application, and the scope of the present application is not limited thereto, but any insubstantial changes and substitutions made by those skilled in the art on the basis of the present application are intended to be within the scope of the present application.

Claims (9)

1. A power supply apparatus, characterized in that the power supply apparatus comprises:

a power supply circuit for outputting an alternating current signal;

the switching circuit comprises a first switch and a second switch, the first switch is connected with the alternating current output interface of the power supply equipment, and the second switch is connected with the direct current output interface of the power supply equipment;

the control circuit is connected with the switch circuit and is used for detecting the closing states of the first switch and the second switch and outputting a first control signal according to the closing state of the first switch or outputting a second control signal according to the closing state of the second switch;

the voltage conversion circuit is connected with the power supply circuit, the control circuit and the switch circuit, and is used for carrying out voltage reduction processing on the alternating current signal according to the first control signal when receiving the first control signal and outputting an alternating current signal to the alternating current output interface through the first switch, and is also used for carrying out rectification processing on the alternating current signal according to the second control signal when receiving the second control signal and outputting a direct current signal to the direct current output interface through the second switch;

the voltage conversion circuit comprises a full-bridge unit and a filtering unit, wherein the full-bridge unit is connected with the power supply circuit and comprises a first bridge arm formed by connecting a first upper switching tube and a first lower switching tube in series and a second bridge arm formed by connecting a second upper switching tube and a second lower switching tube in series; the filtering unit is connected with the full-bridge unit and the switching circuit.

2. The power supply apparatus of claim 1, wherein the power supply apparatus further comprises a filter circuit;

the filter circuit is respectively connected with the voltage conversion circuit and the switch circuit, and is used for filtering the electric signal output by the voltage conversion circuit and outputting the electric signal to the switch circuit.

3. The power supply apparatus according to claim 1, wherein the filter unit includes a first inductor, a first capacitor, a second capacitor, and a third switch;

the first end of the first inductor is connected with the bridge arm midpoint of the first bridge arm, and the second end of the first inductor is connected with the switch circuit;

the first end of the first capacitor is connected with the second end of the first inductor, and the second end of the first capacitor is connected with the bridge arm midpoint of the second bridge arm;

the third switch is connected in series with the second capacitor and then connected in parallel with the first capacitor;

the third switch is opened when the first control signal is received and closed when the second control signal is received.

4. A power supply device as claimed in claim 3, characterized in that the capacitance of the second capacitor is larger than the capacitance of the first capacitor.

5. A power supply apparatus according to claim 3, wherein the third switch is a relay.

6. The power supply apparatus of claim 2, wherein the filter circuit comprises a common mode inductance and a third capacitance;

the first end of the common-mode inductor is connected with the voltage conversion circuit, and the second end of the common-mode inductor is connected with the switching circuit;

the third capacitor is connected in parallel between the second ends of the common mode inductors.

7. The power supply apparatus of any one of claims 1 to 6, wherein the power supply circuit comprises an oil-powered alternator.

8. The power supply apparatus of any one of claims 1 to 6, wherein the power supply circuit comprises a dual fuel alternator.

9. A power supply system comprising a power supply device as claimed in any one of claims 1-8.