Programmable voltage source circuit, power supply device and power electronics experiment system

Abstract

The application provides a programmable voltage source circuit, a power supply device and a power electronic device experiment system, relates to the technical field of electronic circuits, and the scheme comprises a voltage source submodule, the voltage source submodule comprises a full-bridge circuit, an alternating current capacitor, a first unidirectional conducting device, an electric reactor and a power compensation module, the alternating current capacitor is connected in parallel with the full-bridge circuit, the first end of the electric reactor is connected with the first bridge arm intermediate node of the full-bridge circuit through the first unidirectional conducting device, the second end of the electric reactor is connected with the second bridge arm intermediate node of the full-bridge circuit, the power compensation module is connected in parallel with the first unidirectional conducting device, and the current flowing out of the electric reactor is compensated for when the current flowing out of the electric reactor is lower than a reference current value, so that the voltage rise or drop of the alternating current capacitor is more stable, and the reliability of the output voltage of the programmable voltage source circuit is improved, and the load object of the circuit can be a converter, namely, the circuit can provide stable voltage for the experiment of the converter.

Description

Technical Field

[0001] This invention relates to the field of electronic circuit technology, specifically to a programmable voltage source circuit, a power supply device, and an experimental system for power electronic devices. Background Technology

[0002] Power electronic devices in power systems are large in capacity and highly coupled with the system. A failure in such devices can have a significant impact on the entire power grid, making direct connection to the actual grid for testing difficult. Equivalent testing methods are typically used, employing specific test equipment to generate the high voltage / high current stress conditions required by the power electronic devices. Testing of power electronic devices usually requires repeated operation under long-term switching steady-state conditions and involves multiple test objectives and core physical processes. Equivalent testing research should start from the overall test objectives, comprehensively considering and equivalently representing the voltage / current stress of all involved physical changes. Higher stress equivalence leads to more reliable evaluation results. During equivalent testing, a programmable voltage source is used as the high voltage / high current power supply. However, the output of the programmable voltage source circuit is affected by the input voltage. When the input voltage fluctuates, the output signal of the programmable voltage source circuit also fluctuates, thus affecting the reliability of the test results. Therefore, ensuring that the programmable voltage source can provide a stable and reliable output is one of the technical problems that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0003] In view of this, embodiments of the present invention provide a programmable voltage source circuit, a power supply device, and a power electronic device experimental system to achieve a stable output programmable voltage source.

[0004] To achieve the above objectives, the embodiments of the present invention provide the following technical solutions:

[0005] A programmable voltage source circuit, comprising:

[0006] Voltage source submodule, the voltage source submodule comprising:

[0007] Full-bridge circuit;

[0008] An AC capacitor connected in parallel with the full-bridge circuit;

[0009] The first unidirectional conducting device, the output terminal of which is connected to the middle node of the first bridge arm of the full-bridge circuit;

[0010] A reactor, wherein the first end of the reactor is connected to the input end of the first unidirectional conducting device, and the second end of the reactor is connected to the middle node of the second bridge arm of the full-bridge circuit;

[0011] A power compensation module, which is connected in parallel with the first unidirectional conducting device, is used to compensate for the current flowing out of the reactor when the current flowing out of the reactor is lower than the reference current value.

[0012] Optionally, in the above programmable voltage source circuit, the full-bridge circuit includes:

[0013] The system comprises a first control switch, a second control switch, a third control switch, and a fourth control switch. The first terminal of the first control switch and the second terminal of the third control switch are connected to the first terminal of the AC capacitor. The second terminal of the second control switch and the first terminal of the fourth control switch are connected to the second terminal of the AC capacitor. The second terminal of the first control switch is connected to the second terminal of the fourth control switch. The first terminal of the third control switch is connected to the first terminal of the second control switch.

[0014] Optionally, in the above programmable voltage source circuit, the power replenishment module includes:

[0015] A current-charged battery, wherein the negative terminal of the current-charged battery is connected to the input terminal of the first unidirectional conducting device;

[0016] The fifth control switch has its first end connected to the output end of the first unidirectional conduction device and its second end connected to the positive terminal of the current-rechargeable battery.

[0017] When the current flowing out of the reactor is lower than the reference current value, the fifth control switch receives the energy replenishment control signal and controls its own on / off state based on the energy replenishment control signal.

[0018] Optionally, in the above programmable voltage source circuit, the first control switch, the second control switch, the third control switch, and the fourth control switch each include:

[0019] Switch body and second unidirectional conduction device;

[0020] The second end of the switch body serves as the second end of the control switch;

[0021] The first end of the switch body is connected to the input end of the second unidirectional conduction device, and the output end of the second unidirectional conduction device serves as the first end of the control switch.

[0022] Optionally, in the above programmable voltage source circuit, the number of voltage source sub-modules is N, where N is a positive integer not less than 2;

[0023] N voltage source submodules are connected in series between the positive and negative input terminals of the power supply.

[0024] Optionally, in the above programmable voltage source circuit, the voltage source submodule further includes:

[0025] A current sensor is used to detect the magnitude of the output current of the reactor;

[0026] A power compensation controller is used to determine whether the current value detected by the current sensor is lower than the reference current value. When it is lower than the reference current value, the power compensation controller outputs a power compensation control signal to the power compensation module to control the power compensation module to perform current compensation.

[0027] Optionally, the above programmable voltage source circuit also includes:

[0028] A full-bridge controller is provided to provide switching control signals based on target logic. The switching control signals are used to control the on and off states of the first control switch, the second control switch, the third control switch and the fourth control switch in the full-bridge circuit, so that the voltage of the AC capacitor switches sequentially between voltage rise, voltage drop and voltage maintenance.

[0029] Optionally, in the above programmable voltage source circuit, the switching control signal output by the full-bridge controller includes:

[0030] The first switch control signal is used to control the first control switch and the second control switch to be turned on, and to control the third control switch and the fourth control switch to be turned off. The first switch control signal is also used to control the voltage of the AC capacitor to be maintained in a voltage boost state.

[0031] The second switch control signal is used to control the first and second control switches to turn off, and to control the third and fourth control switches to turn on. The second switch control signal is also used to control the voltage of the AC capacitor to remain at the voltage drop level.

[0032] The third switch control signal is used to control the first and third control switches to be turned on, and to control the second and fourth control switches to be turned off, or to control the first and third control switches to be turned off and to control the second and fourth control switches to be turned on. The third switch control signal is used to control the voltage of the AC capacitor to be maintained in a voltage maintenance state.

[0033] A power supply device comprising any of the programmable voltage source circuits described above.

[0034] An equivalent experimental system for power electronic devices includes:

[0035] The power electronic device under test and the power supply device for supplying power to the power electronic device under test, wherein the power supply device is the power supply device described above.

[0036] Based on the above technical solution, in the programmable voltage source circuit provided in this embodiment of the invention, the reactor stores energy in the form of current. During operation, the current flows unidirectionally through the first unidirectional conductor, and when the current is lower than the reference current value, it needs to be replenished by the energy replenishment module. The AC capacitor generates a programmable voltage waveform through the charging and discharging process and provides it to external objects via the positive and negative input terminals of the power supply. The energy replenishment module maintains the current flowing out of the reactor stable near the reference current value, and provides timely current compensation when the current is lower than the set current reference value. The full-bridge circuit controls the current path output by the reactor to achieve the switching of the reactor and AC capacitor connection methods. By controlling the switching state of the switching transistors in the full-bridge circuit, the reactor current can have three output states: positive polarity connected to the capacitor, negative polarity connected to the capacitor, and no capacitor connected, i.e., generating three voltage change states on the AC capacitor: voltage rise, voltage drop, and voltage hold. By controlling the switching between these three states, the output voltage can be programmable. Specifically, this includes: adjusting the conduction state of the switching transistors in the full-bridge circuit to allow the reactor output current to charge the AC capacitor in the forward direction, thus raising the voltage across the capacitor; adjusting the conduction state of the switching transistors in the full-bridge circuit to allow the reactor output current to charge the AC capacitor in the reverse direction, thus lowering the voltage across the capacitor; and adjusting the conduction state of the switching transistors in the full-bridge circuit to disconnect the circuit between the reactor and the AC capacitor, thus maintaining the voltage across the capacitor. Simultaneously, the magnitude of the current flowing out of the reactor is monitored in real time. When the current flowing out of the reactor is lower than a reference current value, current compensation is performed on the current flowing out of the reactor to make the voltage rise or fall across the AC capacitor more stable, thereby improving the reliability of the output voltage of the programmable voltage source circuit. Attached Figure Description

[0037] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0038] Figure 1 This is a schematic diagram of a programmable voltage source circuit provided in an embodiment of this application;

[0039] Figure 2A schematic diagram of a programmable voltage source circuit provided in another embodiment of this application;

[0040] Figure 3 This is a schematic diagram of the control flow of the programmable voltage source circuit disclosed in the embodiments of this application;

[0041] Figure 4 A schematic diagram of the voltage waveform provided for the voltage source in the existing scheme;

[0042] Figure 5 A schematic diagram of the voltage waveform provided for the programmable voltage source circuit disclosed in this application. Detailed Implementation

[0043] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0044] The programmable voltage source circuit of this invention responds to the engineering requirements of power electronic equipment testing, aiming to reduce equipment costs and improve the equivalence of voltage stress output devices. For details, see [link to details]. Figure 1 The programmable voltage source circuit provided in this application includes a voltage source submodule 100. The number of voltage source submodules in the programmable voltage source circuit can be set according to design requirements. For example, the number of voltage source submodules 100 can be 1 or N, where N is a positive integer not less than 2. When the number of voltage source submodules 100 is N, the N voltage source submodules are connected in series between the positive power input terminal V+ and the negative power input terminal V-. The positive power input terminal V+ and the negative power input terminal V- are used to connect to a load, which can be a converter or other equipment. That is, the programmable voltage source circuit can provide a stable voltage to the converter.

[0045] For details, see Figure 1 At this time, the input and output terminals of N voltage source sub-modules 100 are connected in series to form the programmable voltage source circuit in this application. In order to reduce design costs and facilitate control, these voltage source sub-modules 100 adopt the same structure.

[0046] The voltage source submodule includes a full-bridge circuit H, an AC capacitor C, a first unidirectional conducting device D1, a reactor L, and a power replenishment module 101.

[0047] The output terminal of the first unidirectional conducting device D1 is connected to the middle node O1 of the first bridge arm of the full-bridge circuit;

[0048] The first end of the reactor L is connected to the input end of the first unidirectional conducting device D1, and the second end of the reactor L is connected to the middle node O2 of the second bridge arm of the full-bridge circuit H. The reactor L can generate current by mutual inductance with other inductors and store energy in the form of current.

[0049] The power compensation module 101 is connected in parallel with the first unidirectional conducting device D1. It is used to compensate for the current flowing out of the reactor L when the current is lower than the reference current value, so that the current flowing out of the reactor L is stabilized near the reference current value. When the power compensation module 101 performs current compensation, the first unidirectional conducting device D1 can prevent the compensation current output by the power compensation module 101 from flowing back into the reactor L.

[0050] In the circuit described above, the reactor L stores energy in the form of current. During operation, this current flows unidirectionally through the first unidirectional conducting device D1, and when the current falls below the reference current value, it needs to be replenished by the energy replenishment module 101. The AC capacitor C generates a programmable voltage waveform through the charging and discharging process and provides it to external objects via the positive input terminal V+ and the negative input terminal V-. The energy replenishment module maintains the current flowing out of the reactor stable near the reference current value, providing timely current compensation when the current falls below the set reference value. The full-bridge circuit controls the current path output by the reactor to change the connection method between the reactor and the AC capacitor. By controlling the switching state of the switching transistors in the full-bridge circuit, the reactor current can have three output states: positive polarity connected to the capacitor, negative polarity connected to the capacitor, and no capacitor connected, resulting in three voltage change states on the AC capacitor: voltage rise, voltage drop, and voltage hold. By controlling the switching between these three states, the output voltage can be programmable. Specifically, this includes: adjusting the conduction state of the switching transistors in the full-bridge circuit to allow the current output from reactor L to charge AC capacitor C in the forward direction, thus raising the voltage across the capacitor; adjusting the conduction state of the switching transistors in the full-bridge circuit to allow the current output from reactor L to charge AC capacitor C in the reverse direction, thus lowering the voltage across the capacitor; and adjusting the conduction state of the switching transistors in the full-bridge circuit to disconnect the circuit between reactor L and AC capacitor C, thus maintaining the voltage across the capacitor. Simultaneously, the magnitude of the current flowing out of reactor L is monitored in real time. When the current flowing out of reactor L decreases due to voltage fluctuations in the mutual inductance object, and the current flowing out of the reactor is lower than the reference current value, current compensation is performed on the current flowing out of reactor L to maintain it near the reference current. This makes the voltage rise or fall across AC capacitor C more stable, improving the reliability of the output voltage of the programmable voltage source circuit, and thus making the input voltage of the load (such as a converter) more stable and reliable.

[0051] When the programmable voltage source circuit includes N voltage source sub-modules, the N voltage source sub-modules are synchronously controlled. By connecting the N voltage source sub-modules 100 in series, the amplitude of the AC voltage provided by the AC capacitor C of each voltage source sub-module 100 in the synchronous state can be continuously superimposed to achieve the voltage range required by the test load.

[0052] In this embodiment, the full-bridge circuit can be a full-bridge circuit composed of multiple switching transistors. For details, see [link to documentation]. Figure 1The full-bridge circuit includes a first control switch T1, a second control switch T2, a third control switch T3, and a fourth control switch T4. The first terminal of the first control switch T1 and the second terminal of the third control switch T3 are connected to the first terminal of the AC capacitor C. The second terminal of the second control switch T2 and the first terminal of the fourth control switch T4 are connected to the second terminal of the AC capacitor C. The second terminal of the first control switch T1 is connected to the second terminal of the fourth control switch T4. The first terminal of the third control switch T3 is connected to the first terminal of the second control switch T2. The common terminal of the first control switch T1 and the second control switch T2 serves as the first bridge arm intermediate node O1 of the full-bridge circuit, and the common terminal of the third control switch T3 and the fourth control switch T4 serves as the second bridge arm intermediate node O2 of the full-bridge circuit.

[0053] In this embodiment, the on / off states of the first control switch T1, the second control switch T2, the third control switch T3, and the fourth control switch T4 are controlled by a full-bridge controller. The full-bridge controller provides switch control signals based on target logic. These switch control signals control the on / off states of the first control switch T1, the second control switch T2, the third control switch T3, and the fourth control switch T4, causing the voltage of the AC capacitor to switch sequentially between voltage rise, voltage drop, and voltage maintenance. Specifically, the switch control signals include a first switch control signal, a second switch control signal, and a third switch control signal. These signals control the state of the capacitor voltage provided by the AC capacitor C. The voltage source submodule 100 has three states: voltage rise, voltage drop, and voltage maintenance. When the voltage source submodule 100 is in the voltage rise state, the controller provides the first switch control signal. This first switch control signal controls the first control switch T1 and the second control switch T2 to be on, and controls the third control switch T3 and the fourth control switch T4 to be on. 4. When the reactor L is turned off, the current flowing out of the reactor L flows through the first control switch T1 and the second control switch T2 in sequence, and charges the AC capacitor C in the forward direction, causing the capacitor voltage on the AC capacitor C to rise. When the voltage source submodule 100 is in a voltage drop state, the controller provides a second switch control signal. The second switch control signal is used to control the first control switch T1 and the second control switch T2 to turn off, and control the third control switch T3 and the fourth control switch T4 to turn on. At this time, the current flowing out of the reactor L flows through the third control switch T3 and the fourth control switch T4 in sequence, and charges the AC capacitor C in the reverse direction, causing the capacitor voltage on the capacitor to drop. When the voltage source submodule 100 is in a voltage maintenance state, the controller provides a third switch control signal. The third switch control signal is used to control the first control switch T1 and the third control switch T3 to be turned on, and to control the second control switch T2 and the fourth control switch T4 to be turned off. Alternatively, the third switch control signal is used to control the first control switch T1 and the third control switch T3 to be turned off, and to control the second control switch T2 and the fourth control switch T4 to be turned on. At this time, the current flowing out of the reactor L continues to flow in the path formed by the first control switch T1 and the third control switch T3, or continues to flow in the path formed by the second control switch T2 and the fourth control switch T4. This current does not flow to the AC capacitor C, and does not charge or discharge the AC capacitor C, so the capacitor voltage is maintained.

[0054] In this embodiment, the power replenishment module 101 may include a current replenishment battery E and a fifth control switch T5. The negative terminal of the current replenishment battery E is connected to the input terminal of the first unidirectional conducting device D1; the first terminal of the fifth control switch T5 is connected to the output terminal of the first unidirectional conducting device D1, and the second terminal of the fifth control switch T5 is connected to the positive terminal of the current replenishment battery E. By controlling the duty cycle of the fifth control switch T5, the magnitude of the compensation current of the power replenishment module can be adjusted. When the current output by the reactor L is insufficient, the current replenishment module compensates for the output current of the reactor L. Specifically, the function of the power replenishment module is to maintain the output current of the reactor L near a reference current value. The reference current value can be a periodically changing full-wave rectified waveform signal, and the magnitude of the reference current value changes periodically with time. When the current flowing out of the reactor L is lower than the reference current, the power replenishment module is controlled to provide compensation current so that the current flowing out of the reactor L remains near the reference current value. Therefore, the control state of the fifth control switch T5 is related to the magnitude of the current flowing through the reactor L. When the current flowing through the reactor L is lower than the reference current, the fifth control switch T5 is turned on; when the current flowing through the reactor L reaches the reference current, the fifth control switch T5 is turned off. To detect the output current of the reactor L and control the energy compensation module, the programmable voltage source circuit may also include a current sensor and an energy compensation controller. The current sensor is used to detect the magnitude of the output current of the reactor; the energy compensation controller is used to determine whether the current value detected by the current sensor is lower than the reference current value. When it is lower than the reference current value, it outputs an energy compensation control signal to the energy compensation module to control the energy compensation module to perform current compensation.

[0055] In this embodiment, considering that a fault in the voltage source submodule 100 would affect the overall output of the programmable voltage source circuit, or that an open-circuit fault in the voltage source submodule 100 might lead to the overall failure of the programmable voltage source circuit, this embodiment further includes N voltage source bypass switches to prevent the faulty voltage source submodule 100 from affecting the overall output of the programmable voltage source circuit. Each voltage source bypass switch corresponds one-to-one with a voltage source submodule 100. One end of each voltage source bypass switch is connected to the input terminal of the corresponding voltage source submodule 100, and the other end is connected to the output terminal of the corresponding voltage source submodule 100. In this solution, a fault detection circuit can detect whether a voltage source submodule 100 has a fault. When a fault is detected in a voltage source submodule 100, the voltage source bypass switch connected to the faulty voltage source submodule 100 is turned on, short-circuiting the faulty voltage source submodule 100 and causing it to disconnect from the programmable voltage source circuit.

[0056] In this embodiment, the AC capacitor C is composed of M sub-capacitors connected in series, parallel, or a combination of series and parallel connections, and each sub-capacitor is connected in parallel with a capacitor bypass switch. In this solution, the capacitor bypass switch can be controlled based on the load's voltage requirements and the health status of the sub-capacitors. By adjusting the conduction state of the capacitor bypass switch, the number of sub-capacitors in the AC capacitor C can be adjusted, thereby regulating the amplitude of the output voltage of the AC capacitor C. This effectively improves the adjustment range of the output voltage of the programmable voltage source circuit.

[0057] In this embodiment, when the full-bridge controller controls the full-bridge circuit based on the target logic, the control flow can be as follows: [See...] Figure 3 The control process includes:

[0058] Step S301: Calculate the voltage difference between the output voltage of the programmable voltage source circuit and the reference voltage;

[0059] In this embodiment, the error boundary ΔV of the output voltage of the programmable voltage source circuit can be set according to the circuit design requirements. In this step, the output voltage Vc (the voltage between the positive input terminal V+ and the negative input terminal V- of the power supply) of the programmable voltage source circuit is acquired by a voltage sensor or similar device, the voltage difference Verror between the output voltage Vc and the reference voltage Vcref is calculated, and the voltage difference Verror is sent to the hysteresis comparator.

[0060] The reference voltage Vcref is a pre-configured waveform that varies with a time period. This waveform can be a sine or cosine waveform that varies with time. When the programmable voltage source circuit is working, it reads the current value of the reference voltage Vcref in real time and calculates the voltage difference between the output voltage Vc and the real-time read reference voltage Vcref. The waveform of the reference voltage Vcref is synchronized with the reference current value described above.

[0061] Step S302: Determine whether the absolute value of the voltage difference is less than or equal to the error boundary;

[0062] The real-time difference between the calculated real-time output voltage Vc and the real-time reference voltage Vcref is compared with the error boundary ΔV to determine whether the difference is less than or equal to the error boundary ΔV.

[0063] Step S303: When the absolute value of the voltage difference is less than or equal to the error boundary, determine whether the rate of change of the reference voltage Vcref is greater than the target rate of change C0;

[0064] The target rate of change is a preset value, which is used to characterize that the output voltage is about to reach the set maximum or minimum value.

[0065] Step S304: When the rate of change of the reference voltage Vcref is greater than the target rate of change C0, change the drop control logic of the hysteresis comparator output to the sustain control logic.

[0066] When the hysteresis comparator outputs drop control logic, the full-bridge controller outputs a second switch control signal. When the hysteresis comparator outputs sustain control logic, the full-bridge controller outputs a third switch control signal. In this step, when step S303 detects that the rate of change of the reference voltage Vcref is greater than the target rate of change C0, the full-bridge controller switches from outputting the second switch control signal to outputting the third switch control signal.

[0067] In this scheme, the switching control signals output by the full-bridge controller are switched in the following order: first switching control signal - third switching control signal - second switching control signal - third switching control signal - first switching control signal...

[0068] Step S305: When the rate of change of the reference voltage Vcref is less than or equal to the target rate of change C0, change the boost control logic of the hysteresis comparator output to the sustain control logic.

[0069] When the hysteresis comparator outputs the boost control logic, the full-bridge controller outputs the first switch control signal. When the hysteresis comparator outputs the hold control logic, the full-bridge controller outputs the third switch control signal. In this step, when step S303 detects that the rate of change of the reference voltage Vcref is less than or equal to the target rate of change C0, the controller switches from the state of outputting the first switch control signal to the state of outputting the third switch control signal.

[0070] Step S306: When the absolute value of the voltage difference is greater than the error boundary, change the control logic output of the hysteresis comparator from the maintenance control logic to the rise control logic or the fall control logic.

[0071] In this step, when the absolute value of the voltage difference is greater than the error boundary, it indicates that the output voltage needs to decrease or increase. At this time, the output signal of the full-bridge controller switches to the next switching control signal, which is either the first switching control signal or the second switching control signal. In this step, the full-bridge controller can determine whether it needs to output the first or second switching control signal based on the sequence of "first switching control signal - third switching control signal - second switching control signal - third switching control signal - first switching control signal...".

[0072] Taking a sinusoidal signal with an amplitude of 2000 V and a frequency of 50 Hz as a reference voltage, and setting the error boundary ΔV = 45 V, calculations show that, under the premise of meeting the set ΔV error boundary, [see...]. Figure 4The total harmonic distortion of the output voltage in the traditional scheme is 2.45%, and the switching frequency of the components within the device is 100kHz. (See [link / reference]). Figure 5 In the technical solution disclosed in this application, the total harmonic distortion of the output voltage of the programmable voltage source circuit is 1.52%, and the switching frequency of the switching devices within the programmable voltage source circuit is 2kHz. It is evident that the control method provided in this application significantly reduces the switching frequency of the switching devices, resulting in lower output voltage distortion, lower heat generation, and improved output waveform equivalence. Furthermore, the controller described in this application can synchronously control at least a portion of the voltage source sub-modules 100 within the programmable voltage source circuit.

[0073] In summary, the above-disclosed solution of this invention has the following advantages: In terms of cost, a programmable voltage waveform can be provided to the load object through a simple circuit, resulting in simple circuit design and low cost. Regarding equivalence, the proposed circuit structure and control method ensure high equivalence of the output voltage stress waveform. In terms of economy, this solution supports the output of arbitrary high-voltage waveforms, possesses a wide voltage range and flexible control, and avoids the redundant construction of voltage source devices. Furthermore, in terms of convenience, the proposed solution uses a single voltage source, eliminating the complexity of multi-source coordinated control and improving operational convenience. In terms of reliability, the optimized control method significantly reduces the switching frequency of internal components, thereby enhancing the long-term operational reliability of the overall device. Finally, in terms of scalability, this solution consists of voltage source sub-modules, and the output voltage stress level can be changed by adjusting the number of modules, exhibiting good scalability and facilitating integration into the overall equivalent test system.

[0074] This embodiment discloses a power supply device, which includes any of the programmable voltage source circuits and controllers provided in the above embodiments. The controller includes a full-bridge controller and a power replenishment controller.

[0075] This embodiment discloses an equivalent experimental system for a power electronic device. The system includes a power electronic device to be tested and a power supply device for supplying power to the power electronic device to be tested (such as a converter). The power supply device is the power supply device described above.

[0076] For ease of description, the above system is described by dividing it into various modules based on their functions. Of course, in implementing this invention, the functions of each module can be implemented in one or more software and / or hardware components.

[0077] The various embodiments in this specification are described in a progressive manner. Similar or identical parts between embodiments can be referred to mutually. Each embodiment focuses on describing the differences from other embodiments. In particular, for system or system embodiments, since they are basically similar to method embodiments, the description is relatively simple, and relevant parts can be referred to the descriptions in the method embodiments. The systems and system embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Those skilled in the art can understand and implement this without creative effort.

[0078] Those skilled in the art will further recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of both. To clearly illustrate the interchangeability of hardware and software, the components and steps of the various examples have been generally described in terms of functionality in the foregoing description. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementations should not be considered beyond the scope of this invention.

[0079] The steps of the methods or algorithms described in conjunction with the embodiments disclosed herein can be implemented directly by hardware, a software module executed by a processor, or a combination of both. The software module can be located in random access memory (RAM), main memory, read-only memory (ROM), electrically programmable ROM, electrically erasable programmable ROM, registers, hard disk, removable disk, CD-ROM, or any other form of storage medium known in the art.

[0080] It should also be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0081] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A programmable voltage source circuit, characterized in that, include: Voltage source submodule, the voltage source submodule comprising: Full-bridge circuit; An AC capacitor connected in parallel with the full-bridge circuit; The first unidirectional conducting device, the output terminal of which is connected to the middle node of the first bridge arm of the full-bridge circuit; A reactor, wherein the first end of the reactor is connected to the input end of the first unidirectional conducting device, and the second end of the reactor is connected to the middle node of the second bridge arm of the full-bridge circuit; A power compensation module, which is connected in parallel with the first unidirectional conducting device, is used to compensate for the current flowing out of the reactor when the current flowing out of the reactor is lower than the reference current value.

2. The programmable voltage source circuit according to claim 1, characterized in that, The full-bridge circuit includes: The system comprises a first control switch, a second control switch, a third control switch, and a fourth control switch. The first terminal of the first control switch and the second terminal of the third control switch are connected to the first terminal of the AC capacitor. The second terminal of the second control switch and the first terminal of the fourth control switch are connected to the second terminal of the AC capacitor. The second terminal of the first control switch is connected to the second terminal of the fourth control switch. The first terminal of the third control switch is connected to the first terminal of the second control switch.

3. The programmable voltage source circuit according to claim 1, characterized in that, The energy replenishment module includes: A current-charged battery, wherein the negative terminal of the current-charged battery is connected to the input terminal of the first unidirectional conducting device; The fifth control switch has its first end connected to the output end of the first unidirectional conduction device and its second end connected to the positive terminal of the current-rechargeable battery. When the current flowing out of the reactor is lower than the reference current value, the fifth control switch receives the energy replenishment control signal and controls its own on / off state based on the energy replenishment control signal.

4. The programmable voltage source circuit according to claim 2, characterized in that, The first control switch, the second control switch, the third control switch, and the fourth control switch each include: Switch body and second unidirectional conduction device; The second end of the switch body serves as the second end of the control switch; The first end of the switch body is connected to the input end of the second unidirectional conduction device, and the output end of the second unidirectional conduction device serves as the first end of the control switch.

5. The programmable voltage source circuit according to claim 1, characterized in that, The number of voltage source submodules is N, where N is a positive integer not less than 2; N voltage source submodules are connected in series between the positive and negative input terminals of the power supply.

6. The programmable voltage source circuit according to claim 1, characterized in that, The voltage source submodule also includes: A current sensor is used to detect the magnitude of the output current of the reactor; A power compensation controller is used to determine whether the current value detected by the current sensor is lower than the reference current value. When it is lower than the reference current value, the power compensation controller outputs a power compensation control signal to the power compensation module to control the power compensation module to perform current compensation.

7. The programmable voltage source circuit according to claim 2, characterized in that, Also includes: A full-bridge controller is provided to provide switching control signals based on target logic. The switching control signals are used to control the on and off states of the first control switch, the second control switch, the third control switch and the fourth control switch in the full-bridge circuit, so that the voltage of the AC capacitor switches sequentially between voltage rise, voltage drop and voltage maintenance.

8. The programmable voltage source circuit according to claim 7, characterized in that, The switching control signals output by the full-bridge controller include: The first switch control signal is used to control the first control switch and the second control switch to be turned on, and to control the third control switch and the fourth control switch to be turned off. The first switch control signal is also used to control the voltage of the AC capacitor to be maintained in a voltage boost state. The second switch control signal is used to control the first and second control switches to turn off, and to control the third and fourth control switches to turn on. The second switch control signal is also used to control the voltage of the AC capacitor to remain at the voltage drop level. The third switch control signal is used to control the first and third control switches to be turned on, and to control the second and fourth control switches to be turned off, or to control the first and third control switches to be turned off and to control the second and fourth control switches to be turned on. The third switch control signal is used to control the voltage of the AC capacitor to be maintained in a voltage maintenance state.

9. A power supply device, characterized in that, Includes the programmable voltage source circuit as described in any one of claims 1-8.

10. An equivalent experimental system for a power electronic device, characterized in that, include: The power electronic device under test and the power supply device for supplying power to the power electronic device under test, wherein the power supply device is the power supply device as described in claim 9.

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