Integrated power supply device and method for multiple test items of circuit breaker

Abstract

The invention discloses an integrated power supply device and method for multiple test items of a circuit breaker, and relates to the technical field of circuit breaker testing. Aiming at the problems that two sets of independent power supplies are needed and the operation is tedious in the existing test, the device comprises a rectification module, a power conversion module, a double-winding transformer, two paths of rectification filtering modules, a feedback control module and a switching device. 220V commercial power is converted into direct current through the rectification module, the power conversion module outputs adjustable square wave voltage, after transformation ratio conversion of the double-winding transformer, the two paths of rectification filtering modules output 10-100A adjustable direct current and 40-260V adjustable direct current voltage respectively, and the feedback control module stabilizes the output within the error of + / -2% of a target value. The switching device controls two paths to be independently connected and disconnected through interlocking, and the over-current protection module is triggered to stop when the current exceeds 110 A / 11A. According to the invention, a single device satisfies two test power supply, the size and weight are reduced, the cost is saved, wiring operation and safety risks are reduced, and the test efficiency is improved.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of circuit breaker testing and relates to an integrated power supply device and method for multiple test items of a circuit breaker. BACKGROUND

[0002] As a core device for ensuring the safe operation of a circuit in a power system, the performance reliability of a circuit breaker is directly related to the stability of a power grid and the safety of power consumption. In the scenarios of production and factory detection, operation and maintenance preventive test, etc. of a circuit breaker, loop resistance test and mechanical property test are two indispensable key detection items, and the parameter requirements of the power supply for the two items are significantly different: the loop resistance test needs to rely on a large current power supply (usually 10-100 A adjustable), and the contact resistance and conduction performance of the conduction loop are accurately evaluated by measuring the voltage drop when the current flows through the circuit breaker; the mechanical property test needs a wide range of adjustable DC voltage (usually 40-260 V adjustable), and a stable driving power is provided for the operating mechanism of the circuit breaker to test the key mechanical parameters such as the on-off time and the action speed.

[0003] At present, a separate power supply scheme is generally adopted in the industry, that is, a special power supply device is configured for each test: a large current constant current source is used for loop resistance test, and an adjustable DC voltage stabilizing power supply is used for mechanical property test. This scheme has many outstanding problems in actual application: first, the procurement cost of two independent devices is high, and the devices are large in size and heavy in weight, especially in outdoor field test or frequent mobile test scenarios, which is extremely inconvenient for carrying and transporting; second, the power supply needs to be switched by detaching and replacing the wiring multiple times during the test, and the operation process is complicated, which not only prolongs the test period and reduces the overall test efficiency, but also increases the risk of wiring errors; third, there is a lack of effective interlocking mechanism, and if the two power supplies are connected to the circuit breaker at the same time due to misoperation, it may cause power supply short circuit, equipment burning and even personnel safety accidents; fourth, the control systems of the two power supplies are independent of each other, and the test parameters cannot be adjusted and automatically controlled cooperatively, which is difficult to adapt to modern high-efficiency test requirements. These problems seriously restrict the convenience, safety and efficiency of circuit breaker testing, and therefore an integrated and highly reliable power supply solution is urgently needed. SUMMARY

[0004] The purpose of the present application is to provide an integrated power supply device and method for multiple test items of a circuit breaker, which solves the problems of device redundancy, complicated operation and low safety in the separate power supply scheme.

[0005] In order to solve the above problems, the technical scheme of the present application is as follows: An integrated power supply device for multiple test items of a circuit breaker includes a rectifier module, a power conversion module, a dual-winding transformer, a first rectifier and filter module, a second rectifier and filter module, a feedback control module, and a switching device. The rectifier module is connected to the power conversion module and converts AC input into DC voltage to power the power conversion module. The power conversion module is connected to the primary winding of the dual-winding transformer and converts the DC voltage into an adjustable square wave voltage output to the dual-winding transformer. The two secondary windings of the dual-winding transformer are respectively connected to the first rectifier and filter module and the second rectifier and filter module, outputting corresponding voltage signals through different winding ratios. The first rectifier and filter module outputs a DC current that meets the requirements for circuit breaker circuit resistance testing, and the second rectifier and filter module outputs a DC voltage that meets the requirements for circuit breaker mechanical characteristic testing. The feedback control module is connected to the power conversion module, the first rectifier and filter module, and the second rectifier and filter module, and adjusts the output parameters of the power conversion module according to the output feedback signal. The switching device is connected to the output terminals of the first and second rectifier and filter modules and controls the independent on / off and interlocking of the two outputs.

[0006] Furthermore, the rectifier module is a bridge rectifier structure, with its input end connected to AC mains power and its output end connected to the DC input end of the power conversion module.

[0007] Furthermore, the power conversion module uses IGBTs as switching devices to adjust the duty cycle of the output square wave according to the control signal from the feedback control module.

[0008] Furthermore, the two secondary windings of the dual-winding transformer have different turns ratios, wherein the turns ratio of the first secondary winding connected to the first rectifier and filter module is 1:2-1:10, and the turns ratio of the second secondary winding connected to the second rectifier and filter module is 1:15-1:150.

[0009] Furthermore, the first rectifier and filter module includes a rectifier unit and an LC filter unit connected in sequence, used to convert the AC signal output by the dual-winding transformer into a low-ripple DC current.

[0010] Furthermore, the second rectifier and filter module converts the AC signal output from the dual-winding transformer into an adjustable DC voltage through a rectifier circuit and a capacitor filter network.

[0011] Furthermore, the feedback control module includes a voltage sampling unit, a reference voltage unit, and a comparison adjustment unit. The voltage sampling unit collects the output voltages of the first and second rectifier filter modules, compares them with the preset voltage of the reference voltage unit, and then outputs a control signal to the power conversion module through the comparison adjustment unit.

[0012] Furthermore, the switching device is an electromagnetic relay or a solid-state relay, and its control terminal is connected to an external test command unit.

[0013] Furthermore, it also includes a protection module, which is connected to the output circuits of the first rectifier and filter module and the second rectifier and filter module. When the output current is detected to exceed the preset threshold range, it sends a protection signal to the feedback control module to control the power conversion module to stop outputting.

[0014] A method for supplying power to multiple test items of a circuit breaker with an integrated power supply device includes the following steps: S1: The AC input is converted into DC voltage through the rectifier module to provide operating power for the power conversion module; S2: Under the initial control of the feedback control module, the power conversion module outputs a square wave voltage with a preset duty cycle to the primary side of the dual-winding transformer. S3: The dual-winding transformer outputs corresponding voltage signals to the first rectifier and filter module and the second rectifier and filter module respectively through two secondary windings with different turns ratios; S4: The first rectifier and filter module converts the received voltage signal into a DC current that meets the requirements of the loop resistance test, and the second rectifier and filter module converts the received voltage signal into a DC voltage that meets the requirements of the mechanical characteristic test. S5: The feedback control module collects the voltage signals of the two outputs in real time, compares them with the preset reference voltage, generates an adjustment signal, and dynamically adjusts the square wave duty cycle of the power conversion module to keep the two output parameters stable within the preset range. S6: Depending on the type of test item, the corresponding output is turned on by the switching device, while the other output is turned off, so as to realize independent power supply for a single test item; S7: If the protection module detects that the output current exceeds the preset threshold range, the power conversion module will stop outputting.

[0015] The beneficial effects of this invention are as follows: 1. Achieving adjustable high current of 10-100A and adjustable wide-range voltage output of 40-260V simultaneously through a single device eliminates the need for two independent power supplies, significantly reducing equipment procurement costs. Simultaneously, the device's size and weight are reduced by more than 50% compared to traditional solutions, greatly improving portability, making it particularly suitable for mobile scenarios such as outdoor field testing, thus lowering transportation and usage costs.

[0016] 2. With the help of a switching device with interlocking function, the two test power supplies can be quickly switched via external command, eliminating the need for repeated disconnection and wiring, reducing operation steps by more than 60%. The testing process requires no manual intervention in power switching, reducing the total testing time for a single circuit breaker by 30%-40%, significantly improving the efficiency of batch testing or on-site multi-device testing.

[0017] 3. A closed-loop regulation system is constructed through a feedback control module to collect the output voltage signal in real time and dynamically adjust the duty cycle of the power conversion module, so that the current and voltage output are stabilized within the target value ±2% error range and the ripple coefficient ≤5%. Stable output parameters effectively avoid test errors caused by power supply fluctuations and ensure the accuracy and repeatability of test data such as loop resistance and mechanical characteristics.

[0018] 4. The interlocking mechanism of the switching device eliminates the possibility of two outputs being turned on simultaneously from a hardware perspective, completely avoiding the risk of short circuit and equipment burnout; the overcurrent protection module quickly triggers shutdown protection when the output current exceeds 110A (high current circuit) or 11A (voltage circuit), effectively protecting the internal circuit of the device and the circuit breaker under test from overload damage, improving the safety of the testing process and the service life of the equipment.

[0019] 5. The adjustable range of high current (10-100A) and wide voltage (40-260V) can cover the mainstream specifications and models of medium and low voltage circuit breakers; the transformation ratio design of the dual-winding transformer (1:2-1:10, 1:15-1:150) and the coordinated adjustment of the power conversion module can flexibly adapt to the test parameter requirements of different manufacturers and different types of circuit breakers without the need for additional adapter accessories, making it suitable for a wide range of scenarios. Attached Figure Description

[0020] The invention will be further described below with reference to the accompanying drawings: Figure 1 This is a schematic diagram of the structure of the present invention.

[0021] In the diagram: 1. Rectifier module; 2. Power conversion module; 3. First rectifier and filter module; 4. Second rectifier and filter module; 5. Switching device; 6. Feedback control module. Detailed Implementation

[0022] 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.

[0023] like Figure 1As shown, an integrated power supply device for multiple test items of a circuit breaker includes a rectifier module 1, a power conversion module 2 (such as an IGBT module), a dual-winding transformer, a first rectifier and filter module 3 (such as a 100A / 6V rectifier and filter module), a second rectifier and filter module 4 (such as a 10A / 260V rectifier and filter module), a feedback control module 6, and a switching device 5. The rectifier module 1 is connected to the power conversion module 2 and is used to convert AC input into DC voltage and supply power to the power conversion module 2. The power conversion module 2 is connected to the primary side of the dual-winding transformer and is used to convert the DC voltage into an adjustable square wave voltage output to the dual-winding transformer. The two secondary windings of the dual-winding transformer are respectively connected to the first rectifier and filter module 3 and the second rectifier and filter module 4, outputting corresponding voltage signals through different winding ratios. The first rectifier and filter module 3 is used to output DC current that meets the circuit breaker circuit resistance test requirements, and the second rectifier and filter module 4... 4 is used to output a DC voltage that meets the mechanical characteristic test requirements of the circuit breaker; the feedback control module 6 includes an AC / DC module and a feedback drive module. The AC / DC module converts the mains power into 24V DC to power the feedback drive module. The feedback drive module in the feedback control module 6 is connected to the power conversion module 2, the first rectifier and filter module 3, and the second rectifier and filter module 4, respectively, and is used to adjust the output parameters of the power conversion module 2 according to the output feedback signal; the switching device 5 is connected to the output terminals of the first and second rectifier and filter modules 4, and is used to control the independent conduction and cutoff of the two outputs, and has an interlock function to prevent the two outputs from conducting simultaneously. This allows a single device to simultaneously meet the power supply requirements of two types of core circuit breaker tests, solving the problems of redundancy and cumbersome operation of separate power supply equipment; the interlock function avoids the short-circuit risk of simultaneous conduction of two outputs, improving test safety and integration.

[0024] Furthermore, the rectifier module 1 is a bridge rectifier structure, with its input terminal connected to AC mains power and its output terminal connected to the DC input terminal of the power conversion module 2, capable of converting AC mains power into a stable DC voltage. This provides a stable DC power supply to the power conversion module 2, ensuring a stable input voltage for the power conversion module 2, reducing the impact of AC input fluctuations on subsequent circuits, and improving the operational stability of the device.

[0025] Furthermore, the power conversion module 2 uses IGBTs as switching devices, operating at a frequency of 1kHz-200kHz. These IGBTs adjust the duty cycle of the output square wave based on the control signal from the feedback control module 6, achieving continuous adjustment of the output voltage amplitude and thus regulating the input voltage of the dual-winding transformer. This adapts the output voltage to the dynamic requirements of different test items. Using IGBTs as switching devices ensures efficient conversion and reliable control at high frequencies, improving the flexibility and response speed of voltage regulation.

[0026] Furthermore, the two secondary windings of the dual-winding transformer have different turns ratios. The first secondary winding connected to the first rectifier and filter module 3 has a turns ratio of 1:2-1:10, while the second secondary winding connected to the second rectifier and filter module 4 has a turns ratio of 1:15-1:150, which can respectively match the voltage conversion requirements of different test items. By adapting the voltage conversion requirements of two types of test items (high current testing requires low voltage and high current conversion, while wide voltage testing requires high voltage conversion), the adjustment pressure of subsequent circuits is reduced, and the adaptability of output parameters and conversion efficiency are improved.

[0027] Furthermore, the first rectifier and filter module 3 includes a rectifier unit and an LC filter unit connected in sequence, used to convert the AC signal output by the dual-winding transformer into a low-ripple DC current, wherein the low-ripple coefficient is no greater than 8%. Providing a low-ripple DC current reduces the impact of current fluctuations on the accuracy of loop resistance testing (avoiding measurement errors caused by ripple), ensuring the accuracy of the test results.

[0028] Furthermore, the second rectifier and filter module 4, through the cooperation of the rectifier circuit and the capacitor filter network, converts the AC signal output from the dual-winding transformer into a stable and adjustable DC voltage. Through coordinated adjustment with the power conversion module 2, it achieves a wide-range voltage output. This stable and adjustable wide-range DC voltage output adapts to the differentiated requirements of different circuit breaker mechanical characteristic tests for drive voltage (such as the voltage levels of different operating mechanisms), improving the compatibility of the device.

[0029] Furthermore, the feedback control module 6 includes a voltage sampling unit, a reference voltage unit, and a comparison and adjustment unit. The voltage sampling unit collects the output voltages of the first and second rectifier-filter modules 4, compares them with the preset voltage of the reference voltage unit, and then outputs a control signal to the power conversion module 2 through the comparison and adjustment unit to stabilize the output voltage within ±5% of the target value. Through closed-loop feedback control, the output deviation is corrected in real time, ensuring the stability of the two output parameters, avoiding output drift caused by power grid fluctuations or load changes, and meeting high-precision testing requirements.

[0030] Furthermore, the switching device 5 is an electromagnetic relay or a solid-state relay, and its control terminal is connected to an external test command unit. Contact interlocking or logic interlocking ensures that the outputs of the first rectifier filter module 3 and the second rectifier filter module 4 do not conduct simultaneously. This achieves safe switching between the two outputs, completely avoiding the risk of a short circuit caused by accidental operation where both power supplies are simultaneously connected to the circuit breaker, protecting the equipment and the circuit breaker under test, and simplifying the test operation process.

[0031] Furthermore, a protection module is included, which is connected to the output circuits of the first rectifier-filter module 3 and the second rectifier-filter module 4. When the output current exceeds a preset threshold range, a protection signal is sent to the feedback control module 6 to control the power conversion module 2 to stop outputting. This achieves overcurrent protection, preventing excessive output current from damaging the internal circuitry of the device or overloading the circuit breaker under test, thus improving the safety and reliability of the device.

[0032] A method for supplying power to multiple test items of a circuit breaker with an integrated power supply device includes the following steps: S1: Power supply initialization: Rectifier module 1 provides operating power to power conversion module 2; First, connect the AC input power supply (such as 220V or 380V AC mains), and connect the AC power supply to the input terminal of rectifier module 1. Rectifier module 1 adopts a bridge rectifier structure, which converts the input sinusoidal AC power into a unidirectional pulsating DC voltage through the unidirectional conductivity of the four internal rectifier diodes. At the same time, the filter capacitor at the output terminal of rectifier module 1 will initially filter out the pulsating component, and finally output a stable DC voltage (such as about 300V DC after rectification of 220V mains power). This DC voltage is directly supplied to the DC input terminal of power conversion module 2, providing a stable energy foundation for the subsequent operation of power conversion module 2 and ensuring that power conversion module 2 has reliable input conditions.

[0033] S2: Initial square wave output: Power conversion module 2 supplies a preset square wave voltage to the dual-winding transformer; Power conversion module 2 starts working under the initial control logic driven by feedback control module 6. Its internal IGBT switching devices operate on and off according to the pulse width modulation (PWM) signal preset by feedback control module 6, with the operating frequency stable within the range of 1kHz-200kHz. By controlling the ratio of IGBT on-time to off-time (i.e., the preset duty cycle, such as 30%-80% according to the initial requirements of the test project), the stable DC voltage input from rectifier module 1 is converted into a square wave voltage with adjustable amplitude. This square wave voltage is precisely delivered to the primary winding of the dual-winding transformer through the terminals, completing the energy conversion and transmission from DC to AC square wave.

[0034] S3: Turns ratio conversion: The dual-winding transformer outputs a matching voltage signal to the two rectifier and filter modules; After receiving the square wave voltage output from the power conversion module 2, the primary winding of the dual-winding transformer induces corresponding voltage signals in the two secondary windings (the first secondary winding and the second secondary winding) with different turns ratios, based on the principle of electromagnetic induction. The first secondary winding, connected to the first rectifier and filter module 3, has a turns ratio of 1:3-1:6, suitable for high-current output requirements. It amplifies the primary square wave voltage proportionally to output a low-voltage, high-current potential AC signal. The second secondary winding, connected to the second rectifier and filter module 4, has a turns ratio of 1:20-1:130, suitable for wide-range voltage output requirements. It amplifies the primary square wave voltage at a higher ratio to output a high-voltage AC signal suitable for mechanical characteristic testing. The voltage signals from the two secondary windings are transmitted to the corresponding first rectifier and filter module 3 and second rectifier and filter module 4 via independent lines.

[0035] S4: AC / DC conversion and filtering: Two-way rectifier and filter modules output the required current / voltage for testing; After receiving the AC signal output from the first secondary winding of the dual-winding transformer, the first rectifier and filter module 3 first converts the AC signal back into a unidirectional pulsating DC signal through an internal rectifier unit (such as a bridge rectifier circuit). Then, the pulsating ripple is deeply filtered out by the LC filter unit (a low-pass filter network composed of inductors and capacitors), and finally outputs a low-ripple DC current with a ripple coefficient ≤ 8%. The amplitude of this current (such as 10-100A) can meet the high current requirements of circuit breaker circuit resistance testing.

[0036] After receiving the AC signal output from the second secondary winding of the dual-winding transformer, the second rectifier and filter module 4 converts the AC signal into a DC signal through an internal rectifier circuit. The voltage fluctuation is further stabilized by a capacitor filter network. In conjunction with the subsequent coordinated adjustment with the power conversion module 2, a stable and adjustable wide-range DC voltage (such as 40-260V) is finally output. This voltage can adapt to the different requirements of the drive voltage for mechanical characteristic testing of different types of circuit breakers.

[0037] S5: Closed-loop feedback regulation: Feedback control module 6 dynamically stabilizes output parameters; Feedback control module 6 initiates the real-time monitoring and adjustment process: its internal voltage sampling unit (such as a high-precision sampling resistor or voltage sensor) continuously collects the output voltage of the first rectifier filter module 3 (indirectly reflecting the output current) and the output voltage of the second rectifier filter module 4, and transmits the collected real-time voltage signal to the comparison and adjustment unit; the comparison and adjustment unit accurately compares the real-time voltage signal with the target voltage value preset by the reference voltage unit (set according to test requirements) and calculates the output deviation; according to the magnitude of the deviation, the comparison and adjustment unit generates a corresponding adjustment signal (such as a PWM duty cycle adjustment command) and sends it to the power conversion module 2; after receiving the adjustment signal, the power conversion module 2 dynamically adjusts the on and off ratios of the IGBT switching devices, thereby changing the duty cycle of the output square wave, and finally stabilizes the two output parameters (current / voltage) within ±5% of the target value error range, avoiding output drift caused by factors such as grid fluctuations and load changes.

[0038] S6: Test circuit switching: Switching device 5 enables independent power supply for a single test item; Based on the actual test requirements (loop resistance test or mechanical characteristic test), the external test command unit sends a switching command to the control terminal of the switching device 5. The switching device 5 uses an electromagnetic relay or a solid-state relay, responding to commands through contact interlocking or logic interlocking mechanisms: if a loop resistance test is performed, the switching device 5 controls the output terminal of the first rectifier filter module 3 to connect to the circuit breaker test interface, while simultaneously forcibly disconnecting the output circuit of the second rectifier filter module 4; if a mechanical characteristic test is performed, the switching device 5 controls the output terminal of the second rectifier filter module 4 to connect to the circuit breaker test interface, while simultaneously forcibly disconnecting the output circuit of the first rectifier filter module 3. This interlocking switching mechanism enables independent power supply for a single test item, ensuring that the two outputs are not simultaneously connected to the circuit breaker.

[0039] S7: Overcurrent Protection: The protection module triggers a shutdown protection to prevent equipment damage; The protection module maintains a real-time connection with the output circuits of the first and second rectifier and filter modules 4, continuously monitoring the magnitude of the two output currents through internal current detection elements (such as current sensors). When the output current of one of the outputs exceeds a preset threshold range (e.g., exceeding 1.1-1.5 times the rated output current, set according to the module's tolerance capability), the protection module immediately generates a protection signal (e.g., a high-level interrupt signal) and quickly sends it to the feedback control module 6. Upon receiving the protection signal, the feedback control module 6 immediately initiates the emergency shutdown logic and outputs a shutdown command to the power conversion module 2. After receiving the shutdown command, the power conversion module 2 quickly cuts off the drive signal of the IGBT switching device, causing the IGBT to stop switching and thus stop outputting a square wave voltage. The dual-winding transformer stops its induced output due to the lack of input voltage, and the first and second rectifier and filter modules 4 also stop outputting current / voltage, ultimately achieving overcurrent protection for the internal circuits of the device and the circuit breaker under test, preventing equipment damage caused by overload.

[0040] The embodiments described in this specification are merely examples of implementations of the inventive concept. The scope of protection of this invention should not be considered as limited to the specific forms stated in the embodiments. The scope of protection of this invention also extends to equivalent technical means that can be conceived by those skilled in the art based on the inventive concept.

Claims

1. A circuit breaker multi-test item integrated power supply device, characterized by, The application relates to a power supply device for circuit breaker test, which comprises a rectifier module, a power conversion module, a double-winding transformer, a first rectifier filter module, a second rectifier filter module, a feedback control module and a switching device; the rectifier module is connected with the power conversion module and is used for converting AC input into DC voltage and supplying power for the power conversion module; the power conversion module is connected with a primary winding of the double-winding transformer and is used for converting the DC voltage into adjustable square wave voltage and outputting the adjustable square wave voltage to the double-winding transformer; two secondary winding groups of the double-winding transformer are respectively connected with the first rectifier filter module and the second rectifier filter module and output corresponding voltage signals through different winding ratios; the first rectifier filter module is used for outputting DC current meeting the requirement of circuit breaker loop resistance test, and the second rectifier filter module is used for outputting DC voltage meeting the requirement of circuit breaker mechanical characteristic test; the feedback control module is connected with the power conversion module, the first rectifier filter module and the second rectifier filter module respectively and is used for adjusting output parameters of the power conversion module according to output feedback signals; and the switching device is connected with output ends of the first and second rectifier filter modules and is used for controlling independent conduction and turn-off of two-way output and interlocking.

2. The integrated power supply for multiple test items of a circuit breaker according to claim 1, wherein, The rectifier module is a bridge rectifier structure, an input end of the rectifier module is connected with AC mains, and an output end of the rectifier module is connected to a DC input end of the power conversion module.

3. The integrated power supply for multiple test items of a circuit breaker of claim 1, wherein, The power conversion module adopts IGBT as a switching device and is used for adjusting a duty cycle of output square wave according to a control signal of the feedback control module.

4. The integrated power supply for multiple test items of a circuit breaker of claim 1, wherein, The two secondary winding groups of the double-winding transformer have different ratios, wherein a first secondary winding group connected with the first rectifier filter module has a ratio of 1:2-1:10, and a second secondary winding group connected with the second rectifier filter module has a ratio of 1:15-1:

150.

5. The integrated power supply for multiple test items of a circuit breaker of claim 1, wherein, The first rectifier filter module comprises a rectifier unit and an LC filter unit connected in sequence and is used for converting AC signals output by the double-winding transformer into low-ripple DC current.

6. The integrated power supply for multiple test items of a circuit breaker of claim 1, wherein, The second rectifier filter module converts AC signals output by the double-winding transformer into adjustable DC voltage through a rectifier circuit and a capacitor filter network.

7. The integrated power supply for multiple test items of a circuit breaker of claim 1, wherein, The feedback control module comprises a voltage sampling unit, a reference voltage unit and a comparison and adjustment unit, the voltage sampling unit collects output voltages of the first and second rectifier filter modules, compares the output voltages with preset voltages of the reference voltage unit, and then outputs a control signal to the power conversion module through the comparison and adjustment unit.

8. The integrated power supply for multiple test items of a circuit breaker of claim 1, wherein, The switching device is an electromagnetic relay or a solid-state relay, and a control end of the switching device is connected with an external test instruction unit.

9. The integrated power supply for multiple test items of a circuit breaker of claim 1, wherein, A protection module is further arranged, the protection module is connected with output loops of the first rectifier filter module and the second rectifier filter module, and when it is detected that output current exceeds a preset threshold range, the protection module sends a protection signal to the feedback control module to control the power conversion module to stop output.

10. A circuit breaker multi-test item power supply method based on the integrated power supply device according to any one of claims 1 to 9, characterized by, The application further relates to a power supply device for circuit breaker test, and the device comprises the following steps: S1: converting AC input into DC voltage through a rectifier module to provide working power for a power conversion module; S2: outputting preset duty cycle square wave voltage to a primary winding of a double-winding transformer under initial control of a feedback control module; S3: The double-winding transformer outputs corresponding voltage signals to the first rectification and filtering module and the second rectification and filtering module through two different secondary winding ratios; S4: The first rectification and filtering module converts the received voltage signal into a direct current that meets the requirements of the loop resistance test, and the second rectification and filtering module converts the received voltage signal into a direct voltage that meets the requirements of the mechanical property test; S5: The feedback control module collects the voltage signals of the two outputs in real time, compares them with the preset reference voltage to generate an adjustment signal, and dynamically adjusts the duty cycle of the power conversion module to stabilize the two output parameters within the preset range; S6: According to the type of the test project, the switching device is controlled to turn on the corresponding output and cut off the other output, thereby realizing independent power supply for a single test project; S7: If the protection module detects that the output current exceeds the preset threshold range, the power conversion module stops outputting.

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