Portable isolation test power supply

Abstract

The invention, which belongs to the technical field of the power supply, discloses a portable isolation test power supply comprising an input protection module, a VFD module, a filter F1, an AC contactor K1, a boosting transformer T1, a three-phase electric detection module, a 24V switching power supply, a voltage-stabilized power supply module, a three-phase rectifier, a high-voltage DC-DC module, a DC output detection module, a driver, an intermediate relay and a main controller. According to the multi-path high-voltage adjustable alternating-current output system, the technical problems of independently monitoring each path of voltage and improving the measurement safety and reliability in the multi-path high-voltage adjustable alternating-current output system are solved, independent sampling, independent processing and non-interference of multi-path output are realized, the system reliability and the fault localization are remarkably improved, reliable electrical isolation of a high-voltage side and a control side is realized, and the reliability of the system is improved. Measurement precision and personal and equipment safety are guaranteed, the intelligent level of the system is improved, the system is suitable for a high-voltage adjustable alternating current output scene, and long-term stable monitoring of the high-voltage state is achieved.

Description

Technical Field

[0001] This invention belongs to the field of power supply technology, and in particular relates to a portable isolated test power supply. Background Technology

[0002] With the widespread application of industrial variable frequency power supplies, power supply vehicles, motor testing systems, and adjustable AC output devices, multi-channel adjustable high-voltage AC output and its real-time voltage monitoring have become key technical requirements. In existing technologies, adjustable AC output is typically achieved using a variable frequency drive (VFD) combined with a step-up transformer, and the output voltage is sampled and monitored through voltage transformers, voltage divider resistors, or isolation amplifiers.

[0003] However, existing technical solutions generally have the following shortcomings:

[0004] Incomplete decoupling between voltage monitoring and main power circuit: Existing solutions mostly adopt a centralized voltage sampling structure, with multiple output channels sharing the voltage detection module. This leads to problems such as complex sampling switching, poor real-time performance, and difficulty in fault location under multi-output conditions. Once a certain channel is abnormal, it is difficult to quickly and accurately determine the cause.

[0005] Insufficient reliability and consistency in high-voltage measurements: In high-voltage AC scenarios (such as 380V~750VAC), some existing solutions use ordinary resistor voltage dividers or low-voltage-resistance devices. Under long-term operation, these solutions are prone to problems such as insufficient withstand voltage margin, large temperature drift, and voltage divider ratio drift, which affect measurement accuracy and system stability.

[0006] Inadequate isolation methods pose safety hazards: Existing technologies commonly use voltage transformers that are large in size and costly, and are complex to arrange in multi-channel applications; while non-isolated or insufficiently isolated analog sampling schemes pose risks of high voltage intrusion into the control system and insufficient anti-interference capabilities, making it difficult to meet the requirements of high reliability applications. Summary of the Invention

[0007] The purpose of this invention is to provide a portable isolated test power supply, which solves the technical problem of independently monitoring the voltage of each channel in a multi-channel high-voltage adjustable AC output system, thereby improving the safety and reliability of measurement.

[0008] To achieve the above objectives, the present invention adopts the following technical solution:

[0009] A portable isolated test power supply includes an input protection module, a VFD module, a filter F1, an AC contactor K1, a step-up transformer T1, a three-phase power detection module, a 24V switching power supply, a regulated power supply module, a three-phase rectifier, a high-voltage DC-DC module, a DC output detection module, a driver, an intermediate relay, and a main controller.

[0010] The input terminal of the input protection module is connected to the mains power, and the output terminal is connected to the VFD module and the 24V switching power supply, respectively.

[0011] The VFD module is connected to filter F1, filter F1 is connected to AC contactor K1, AC contactor K1 is connected to step-up transformer T1, and step-up transformer T1 is connected to the three-phase power detection module.

[0012] Filter F1 is also connected to a three-phase rectifier, which is connected to a high-voltage DC-DC module, and the high-voltage DC-DC module is connected to a DC output detection module.

[0013] The three-phase electrical detection module, the DC output detection module, and the driver are all connected to the main controller; the driver is connected to the intermediate relay, and the intermediate relay is connected to the AC contactor K1.

[0014] The step-up transformer T1 outputs three-phase AC power; the 24V switching power supply outputs 24V power; and the high-voltage DC-DC module outputs high-voltage DC power.

[0015] The regulated power supply module supplies power to the driver, main controller, three-phase power detection module, and DC output detection module; the 24V power supply supplies power to the intermediate relay.

[0016] Preferably, the input protection module is a circuit breaker QF1, and the three-phase power detection module includes voltage transformers VT1, VT2, and VT3, isolation amplifiers A1, A2, and A3, analog-to-digital converters ADC1, ADC2, and ADC3.

[0017] The input terminals L and N of circuit breaker QF1 are connected to the live wire and neutral wire of the mains power supply, respectively; the output terminals L0 and N0 of circuit breaker QF1 are connected to the L and N terminals of the VFD module, respectively.

[0018] The output terminals R, S, and T of the VFD module are all connected to filter F1. Filter F1 is a three-phase filter, and the output terminal of filter F1 outputs three-phase electricity R1 / S1 / T1.

[0019] The three-phase R1 / S1 / T1 is connected to the primary side of the step-up transformer T1 through the AC contactor K1;

[0020] The secondary side of the step-up transformer outputs three-phase electricity L1 / L2 / L3;

[0021] The coil of AC contactor K1 is connected to the intermediate relay;

[0022] Voltage transformers VT1, VT2, and VT3 are respectively installed on phases L1, L2, and L3 of the three-phase L1 / L2 / L3 circuit, and are used to collect the voltage signals of phases L1, L2, and L3 respectively.

[0023] The output of voltage transformer VT1 is connected to analog-to-digital converter ADC1 via isolation amplifier A1;

[0024] The output of voltage transformer VT2 is connected to analog-to-digital converter ADC2 via isolation amplifier A2;

[0025] The output of voltage transformer VT3 is connected to analog-to-digital converter ADC3 via isolation amplifier A3;

[0026] Analog-to-digital converters ADC1, ADC2, and ADC3 are connected to different I / O ports of the main controller.

[0027] The three-phase L1 / L2 / L3 outputs three-phase AC power to the outside through external terminals.

[0028] Preferably, the circuit breaker QF1 is model iC65N2PC16A; the voltage transformers VT1, VT2, and VT3 are all model ZMPT101B; the isolation amplifiers A1, A2, and A3 are all model AMC1301B; the analog-to-digital converters ADC1, ADC2, and ADC3 are all model ADS1115; the VFD module is model INVTGD20-0R7G-S2; the filter F1 is model FN258-10-33; the AC contactor K1 is model LC1D09; the step-up transformer T1 is model 380V to 690V / 1kVA; the main controller is model STM32F407VGT6; and the intermediate relay is a 24V relay, model G2R-1-24VDC.

[0029] Preferably, the input terminals L and N of the 24V switching power supply are connected to the output terminals LO and N0 of the circuit breaker QF1, respectively;

[0030] The 24V switching power supply outputs a 24V power supply at its output terminal.

[0031] The voltage regulator module includes a 5V power supply module and a 3.3V power supply module. The input terminal of the 5V power supply module is connected to a 24V power supply, and the output terminal outputs a 5V power supply. The input terminal of the 3.3V power supply module is connected to a 5V power supply, and the output terminal outputs a 3.3V power supply.

[0032] A 5V power supply powers the drivers, isolation amplifiers A1, A2, and A3; a 3.3V power supply powers the analog-to-digital converters ADC1, ADC2, ADC3, and the main controller.

[0033] Preferably, the 24V switching power supply is of the model MeanWell-LRS-50-24; the 5V power module is of the model LM7805; the 3.3V power module is of the model AMS1117-3.3; and the driver is of the model ULN2003A.

[0034] Preferably, the three-phase rectifier includes diodes D1, D2, D3, D4, D5, and D6, capacitors C1 and C2. Diodes D1, D2, D3, D4, D5, and D6 constitute a three-phase rectifier. The input terminal of the three-phase rectifier is connected to three-phase power supply R1 / S1 / T1, and the output terminal outputs DC bus power supply DCOUT. The DC bus power supply DCOUT includes a positive DC power supply DCOUT+ and a negative DC power supply DCOUT-.

[0035] Both capacitor C1 and capacitor C2 are filter capacitors at the output of the three-phase rectifier;

[0036] The input terminals VIN+ and VIN- of the high-voltage DC-DC module are connected to the positive DC power supply DCOUT+ and the negative DC power supply DCOUT-, respectively; the output terminals VOUT+ and VOUT- of the high-voltage DC-DC module output the positive DC power supply DC1+ and the negative DC power supply DC1-, respectively.

[0037] The DC output detection module includes a high-voltage divider VR1, an isolation amplifier A4, a filter F2, and an analog-to-digital converter ADC4. The high-voltage divider VR1 is connected to the positive power supply DC1+ and is used to divide the positive power supply DC1+ to obtain the voltage acquisition signal of the high-voltage DC power supply. The voltage acquisition signal is input to the input terminal of the isolation amplifier A4. The output terminal of the isolation amplifier A4 is connected to the filter F2. The filter F2 is connected to the analog-to-digital converter ADC4. The analog-to-digital converter ADC4 is connected to the main controller.

[0038] Preferably, the high-voltage DC-DC module is XPPowerHVM12-1000; the high-voltage divider VR1 is a voltage divider composed of multiple high-voltage resistors connected in series; the isolation amplifier A4 is AMC1301B; the filter F2 is an RC low-pass filter network; and the analog-to-digital converter ADC4 is ADS1115.

[0039] This invention discloses a portable isolation test power supply, which solves the technical problem of independently monitoring each voltage in a multi-channel high-voltage adjustable AC output system, thereby improving measurement safety and reliability. Each output channel integrates an independent "voltage monitoring + isolation + ADC" module, enabling independent sampling, processing, and non-interference of multiple outputs. This significantly improves system reliability and fault location. High-voltage, high-stability high-voltage resistor dividers or voltage transformers are used for front-end sampling, coupled with linear optocouplers or isolation amplifiers, to achieve reliable electrical isolation between the high-voltage side and the control side, ensuring measurement accuracy and the safety of personnel and equipment. The voltage sampling signal is digitized by a high-precision ADC and processed in real-time by an ARM controller, supporting functions such as voltage monitoring, over-limit protection, and status reporting, enhancing the system's intelligence level. It is suitable for high-voltage adjustable AC output scenarios, ensuring flexible and adjustable output range while achieving long-term stable monitoring of the high-voltage state. Attached Figure Description

[0040] Figure 1 This is a block diagram illustrating the overall principle of the present invention;

[0041] Figure 2 This is a block diagram of the three-phase main power circuit of the present invention;

[0042] Figure 3 This is a block diagram of the low-voltage power supply circuit of the present invention;

[0043] Figure 4 This is a block diagram of the high-voltage DC power supply circuit of the present invention. Detailed Implementation

[0044] Depend on Figures 1-4 The portable isolation test power supply shown includes an input protection module, a VFD module, a filter F1, an AC contactor K1, a step-up transformer T1, a three-phase power detection module, a 24V switching power supply, a regulated power supply module, a three-phase rectifier, a high-voltage DC-DC module, a DC output detection module, a driver, an intermediate relay, and a main controller.

[0045] The input terminals L and N of the 24V switching power supply are connected to the output terminals LO and N0 of the circuit breaker QF1, respectively.

[0046] The 24V switching power supply outputs a 24V power supply at its output terminal.

[0047] The voltage regulator module includes a 5V power supply module and a 3.3V power supply module. The input terminal of the 5V power supply module is connected to a 24V power supply, and the output terminal outputs a 5V power supply. The input terminal of the 3.3V power supply module is connected to a 5V power supply, and the output terminal outputs a 3.3V power supply.

[0048] A 5V power supply powers the drivers, isolation amplifiers A1, A2, and A3; a 3.3V power supply powers the analog-to-digital converters ADC1, ADC2, ADC3, and the main controller.

[0049] The 24V switching power supply is model MeanWell-LRS-50-24; the 5V power module is model LM7805; the 3.3V power module is model AMS1117-3.3; and the driver is model ULN2003A.

[0050] The 24V switching power supply and regulated power supply module are set up independently of the VFD module and the main power circuit, and are directly powered by the output terminal of the circuit breaker QF1. The purpose is to provide a stable, continuous, and low-voltage operating power supply for the main controller, driver and various detection modules, which is not affected by the fluctuation of the main power circuit.

[0051] The 24V switching power supply adopts a switching AC / DC conversion method to convert the mains power into a stable 24V DC power supply; the voltage regulator module further performs two-stage linear regulation on the basis of the 24V power supply, outputting 5V power and 3.3V power respectively, thereby meeting the different requirements of different functional modules for power supply voltage and power supply noise.

[0052] By electrically isolating and separating the power supply path of the low-voltage control power supply from the VFD output side, the high-voltage AC output side, and the high-voltage DC output side, the impact of VFD modulation process, electromagnetic interference, and high-voltage load changes on the power supply stability of the control and detection systems can be effectively avoided, thereby improving the system's reliability and anti-interference capability under wide voltage regulation range and high power operation conditions.

[0053] Meanwhile, this independent power supply structure ensures that the main controller can still be powered on and operated even if the main power circuit (output of the VFD module) is disconnected or abnormal, thereby realizing status monitoring, fault recording and safety control, and improving the safety and maintainability of the whole machine operation.

[0054] The input terminal of the input protection module is connected to the mains power, and the output terminal is connected to the VFD module and the 24V switching power supply, respectively.

[0055] The VFD module is connected to filter F1, filter F1 is connected to AC contactor K1, AC contactor K1 is connected to step-up transformer T1, and step-up transformer T1 is connected to the three-phase power detection module.

[0056] Filter F1 is also connected to a three-phase rectifier, which is connected to a high-voltage DC-DC module, and the high-voltage DC-DC module is connected to a DC output detection module.

[0057] The input protection module is circuit breaker QF1, and the three-phase power detection module includes voltage transformer VT1, voltage transformer VT2, voltage transformer VT3, isolation amplifier A1, isolation amplifier A2, isolation amplifier A3, analog-to-digital converter ADC1, analog-to-digital converter ADC2, and analog-to-digital converter ADC3.

[0058] The input terminals L and N of circuit breaker QF1 are connected to the live wire and neutral wire of the mains power supply, respectively; the output terminals L0 and N0 of circuit breaker QF1 are connected to the L and N terminals of the VFD module, respectively.

[0059] The output terminals R, S, and T of the VFD module are all connected to filter F1. Filter F1 is a three-phase filter, and the output terminal of filter F1 outputs three-phase electricity R1 / S1 / T1.

[0060] The three-phase R1 / S1 / T1 is connected to the primary side of the step-up transformer T1 through the AC contactor K1;

[0061] The secondary side of the step-up transformer outputs three-phase electricity L1 / L2 / L3;

[0062] The coil of AC contactor K1 is connected to the intermediate relay;

[0063] The three-phase power detection module, DC output detection module, and driver are all connected to the main controller; the driver is connected to the intermediate relay, and the intermediate relay is connected to the AC contactor K1.

[0064] Voltage transformers VT1, VT2, and VT3 are respectively installed on phases L1, L2, and L3 of the three-phase L1 / L2 / L3 circuit, and are used to collect the voltage signals of phases L1, L2, and L3 respectively.

[0065] The output of voltage transformer VT1 is connected to analog-to-digital converter ADC1 via isolation amplifier A1;

[0066] The output of voltage transformer VT2 is connected to analog-to-digital converter ADC2 via isolation amplifier A2;

[0067] The output of voltage transformer VT3 is connected to analog-to-digital converter ADC3 via isolation amplifier A3;

[0068] Analog-to-digital converters ADC1, ADC2, and ADC3 are connected to different I / O ports of the main controller.

[0069] The three-phase L1 / L2 / L3 outputs three-phase AC power to the outside through external terminals.

[0070] The circuit breaker QF1 is model iC65N2PC16A; the voltage transformers VT1, VT2, and VT3 are all model ZMPT101B; the isolation amplifiers A1, A2, and A3 are all model AMC1301B; the analog-to-digital converters ADC1, ADC2, and ADC3 are all model ADS1115; the VFD module is model INVTGD20-0R7G-S2; the filter F1 is model FN258-10-33; the AC contactor K1 is model LC1D09; the step-up transformer T1 is model 380V to 690V / 1kVA; the main controller is model STM32F407VGT6; and the intermediate relay is a 24V relay, model G2R-1-24VDC.

[0071] The VFD module is used for frequency and voltage conversion control of mains power. Its input terminal is connected to the mains power, and after internal rectification, DC bus and inverter unit, it outputs three-phase AC power with adjustable frequency and amplitude. The output terminals R, S, T of the VFD module are filtered by three-phase filter F1 to output three-phase power R1 / S1 / T1, thereby effectively suppressing high-frequency harmonics and electromagnetic interference generated during the inverter process and improving the output voltage waveform quality.

[0072] The filtered three-phase AC power is connected to the primary side of the step-up transformer T1 via AC contactor K1. Under the control of the main controller, AC contactor K1 controls the on / off state of the AC output channel. The step-up transformer T1 transforms the voltage level of the three-phase AC power, and its secondary side outputs three-phase AC power L1 / L2 / L3, which serves as an adjustable frequency and adjustable voltage isolated AC test power supply for external output.

[0073] This embodiment uses a VFD module to achieve continuous adjustment of the frequency and amplitude of the output AC voltage, and combines it with a step-up transformer to expand the voltage level. This allows the device to provide a wide range of adjustable three-phase AC output while maintaining electrical isolation, meeting the needs of various isolation tests and withstand voltage tests. At the same time, through the cooperation of contactors and detection modules, safe control and real-time monitoring of the output status are achieved, improving the safety and controllability of the entire machine operation.

[0074] The step-up transformer T1 outputs three-phase AC power; the 24V switching power supply outputs 24V power; and the high-voltage DC-DC module outputs high-voltage DC power.

[0075] The regulated power supply module supplies power to the driver, main controller, three-phase power detection module, and DC output detection module; the 24V power supply supplies power to the intermediate relay.

[0076] The three-phase rectifier includes diodes D1, D2, D3, D4, D5, and D6, capacitors C1 and C2. Diodes D1, D2, D3, D4, D5, and D6 constitute a three-phase rectifier. The input terminal of the three-phase rectifier is connected to three-phase power supply R1 / S1 / T1, and the output terminal outputs DC bus power supply DCOUT. The DC bus power supply DCOUT includes a positive DC power supply DCOUT+ and a negative DC power supply DCOUT-.

[0077] Both capacitor C1 and capacitor C2 are filter capacitors at the output of the three-phase rectifier;

[0078] The input terminals VIN+ and VIN- of the high-voltage DC-DC module are connected to the positive DC power supply DCOUT+ and the negative DC power supply DCOUT-, respectively; the output terminals VOUT+ and VOUT- of the high-voltage DC-DC module output the positive DC power supply DC1+ and the negative DC power supply DC1-, respectively.

[0079] The DC output detection module includes a high-voltage divider VR1, an isolation amplifier A4, a filter F2, and an analog-to-digital converter ADC4. The high-voltage divider VR1 is connected to the positive power supply DC1+ and is used to divide the positive power supply DC1+ to obtain the voltage acquisition signal of the high-voltage DC power supply. The voltage acquisition signal is input to the input terminal of the isolation amplifier A4. The output terminal of the isolation amplifier A4 is connected to the filter F2. The filter F2 is connected to the analog-to-digital converter ADC4. The analog-to-digital converter ADC4 is connected to the main controller.

[0080] The high-voltage DC-DC module is model XPPowerHVM12-1000; the high-voltage divider VR1 is a voltage divider composed of multiple high-voltage resistors connected in series; the isolation amplifier A4 is model AMC1301B; the filter F2 is an RC low-pass filter network; and the analog-to-digital converter ADC4 is model ADS1115.

[0081] The three-phase rectifier is connected to the three-phase AC output terminals R1 / S1 / T1 of filter F1 to rectify the three-phase AC power into DC bus power DCOUT. This embodiment uses a three-phase full-bridge rectifier structure composed of six diodes, resulting in a rectified DC bus voltage with low ripple and high power utilization. The filter capacitors C1 and C2 at the output terminal further smooth the DC bus voltage, providing a stable input power supply for the subsequent high-voltage DC-DC module.

[0082] The input terminals VIN+ and VIN- of the high-voltage DC-DC module are connected to the DC bus power supply DCOUT+ and DCOUT-, respectively, to convert the DC bus voltage into an isolated high-voltage DC output power supply DC1+ and DC1-. By using an isolated high-voltage DC-DC module, electrical isolation between the input and output sides is achieved, thereby improving the safety of the high-voltage DC output in testing applications.

[0083] The DC output detection module monitors the high-voltage DC output voltage in real time. It scales the high-voltage DC voltage using a high-voltage divider, and after isolation amplification, filtering, and analog-to-digital conversion, the voltage is input to the main controller, enabling accurate sampling and monitoring of the high-voltage DC output status.

[0084] This embodiment achieves high-voltage DC power output using the same three-phase power supply foundation without affecting the AC output function, thus expanding the testing capability range of the device. Furthermore, the isolation detection structure ensures the safety and accuracy of the high-voltage DC measurement process.

[0085] The power supply system includes at least three independent power output paths: an adjustable three-phase AC output power supply based on VFD, a high-voltage DC output power supply based on three-phase rectification and high-voltage DC-DC converter, and a low-voltage DC power supply for powering the control and detection modules. Each power path is independent in terms of power source, energy conversion method, and detection structure, and is electrically isolated through isolation transformers, isolation amplifiers, and isolated DC-DC modules.

[0086] The multi-power isolation architecture in this embodiment enables different types and voltage levels of output to coexist safely in the same device, and achieve independent monitoring and control under the unified management of the main controller, avoiding mutual interference between different power paths and improving the stability, safety and reliability of the system under complex test conditions.

[0087] This invention discloses a portable isolation test power supply, which solves the technical problem of independently monitoring each voltage in a multi-channel high-voltage adjustable AC output system, thereby improving measurement safety and reliability. Each output channel integrates an independent "voltage monitoring + isolation + ADC" module, enabling independent sampling, processing, and non-interference of multiple outputs. This significantly improves system reliability and fault location. High-voltage, high-stability high-voltage resistor dividers or voltage transformers are used for front-end sampling, coupled with linear optocouplers or isolation amplifiers, to achieve reliable electrical isolation between the high-voltage side and the control side, ensuring measurement accuracy and the safety of personnel and equipment. The voltage sampling signal is digitized by a high-precision ADC and processed in real-time by an ARM controller, supporting functions such as voltage monitoring, over-limit protection, and status reporting, enhancing the system's intelligence level. It is suitable for high-voltage adjustable AC output scenarios, ensuring flexible and adjustable output range while achieving long-term stable monitoring of the high-voltage state.

Claims

1. A portable isolation test power supply, characterized in that: It includes an input protection module, a VFD module, a filter F1, an AC contactor K1, a step-up transformer T1, a three-phase power detection module, a 24V switching power supply, a regulated power supply module, a three-phase rectifier, a high-voltage DC-DC module, a DC output detection module, a driver, intermediate relays, and a main controller; The input terminal of the input protection module is connected to the mains power, and the output terminal is connected to the VFD module and the 24V switching power supply, respectively. The VFD module is connected to filter F1, filter F1 is connected to AC contactor K1, AC contactor K1 is connected to step-up transformer T1, and step-up transformer T1 is connected to the three-phase power detection module. Filter F1 is also connected to a three-phase rectifier, which is connected to a high-voltage DC-DC module, which is connected to a DC output detection module. The three-phase electrical detection module, the DC output detection module, and the driver are all connected to the main controller; the driver is connected to the intermediate relay, and the intermediate relay is connected to the AC contactor K1. The step-up transformer T1 outputs three-phase AC power; the 24V switching power supply outputs 24V power; and the high-voltage DC-DC module outputs high-voltage DC power. The regulated power supply module supplies power to the driver, main controller, three-phase power detection module, and DC output detection module; the 24V power supply supplies power to the intermediate relay.

2. The portable isolation test power supply as described in claim 1, characterized in that: The input protection module is circuit breaker QF1, and the three-phase power detection module includes voltage transformer VT1, voltage transformer VT2, voltage transformer VT3, isolation amplifier A1, isolation amplifier A2, isolation amplifier A3, analog-to-digital converter ADC1, analog-to-digital converter ADC2, and analog-to-digital converter ADC3. The input terminals L and N of circuit breaker QF1 are connected to the live wire and neutral wire of the mains power supply, respectively; the output terminals L0 and N0 of circuit breaker QF1 are connected to the L and N terminals of the VFD module, respectively. The output terminals R, S, and T of the VFD module are all connected to filter F1. Filter F1 is a three-phase filter, and the output terminal of filter F1 outputs three-phase electricity R1 / S1 / T1. The three-phase R1 / S1 / T1 is connected to the primary side of the step-up transformer T1 through the AC contactor K1; The secondary side of the step-up transformer outputs three-phase electricity L1 / L2 / L3; The coil of AC contactor K1 is connected to the intermediate relay; Voltage transformers VT1, VT2, and VT3 are respectively installed on phases L1, L2, and L3 of the three-phase L1 / L2 / L3 circuit, and are used to collect phase L1 voltage signals, phase L2 voltage signals, and phase L3 voltage signals, respectively. The output of voltage transformer VT1 is connected to analog-to-digital converter ADC1 via isolation amplifier A1; The output of voltage transformer VT2 is connected to analog-to-digital converter ADC2 via isolation amplifier A2; The output of voltage transformer VT3 is connected to analog-to-digital converter ADC3 via isolation amplifier A3; Analog-to-digital converters ADC1, ADC2, and ADC3 are connected to different I / O ports of the main controller. The three-phase L1 / L2 / L3 outputs three-phase AC power to the outside through external terminals.

3. The portable isolation test power supply as described in claim 2, characterized in that: The circuit breaker QF1 is model iC65N2PC16A; the voltage transformers VT1, VT2, and VT3 are all model ZMPT101B; the isolation amplifiers A1, A2, and A3 are all model AMC1301B; the analog-to-digital converters ADC1, ADC2, and ADC3 are all model ADS1115; the VFD module is model INVTGD20-0R7G-S2; the filter F1 is model FN258-10-33; the AC contactor K1 is model LC1D09; the step-up transformer T1 is model 380V to 690V / 1kVA; the main controller is model STM32F407VGT6; and the intermediate relay is a 24V relay, model G2R-1-24VDC.

4. A portable isolation test power supply as described in claim 2, characterized in that: The input terminals L and N of the 24V switching power supply are connected to the output terminals LO and N0 of the circuit breaker QF1, respectively. The 24V switching power supply outputs a 24V power supply at its output terminal. The voltage regulator module includes a 5V power supply module and a 3.3V power supply module. The input terminal of the 5V power supply module is connected to a 24V power supply, and the output terminal outputs a 5V power supply. The input terminal of the 3.3V power supply module is connected to a 5V power supply, and the output terminal outputs a 3.3V power supply. A 5V power supply powers the driver, isolation amplifiers A1, A2, and A3; a 3.3V power supply powers the analog-to-digital converters ADC1, ADC2, and ADC3, and the main controller.

5. A portable isolation test power supply as described in claim 4, characterized in that: The 24V switching power supply is model MeanWell-LRS-50-24; the 5V power module is model LM7805; the 3.3V power module is model AMS1117-3.3; and the driver is model ULN2003A.

6. A portable isolation test power supply as described in claim 2, characterized in that: The three-phase rectifier includes diodes D1, D2, D3, D4, D5, and D6, capacitors C1 and C2. Diodes D1, D2, D3, D4, D5, and D6 constitute a three-phase rectifier. The input terminal of the three-phase rectifier is connected to three-phase power supply R1 / S1 / T1, and the output terminal outputs DC bus power supply DCOUT. The DC bus power supply DCOUT includes a positive DC power supply DCOUT+ and a negative DC power supply DCOUT-. Both capacitors C1 and C2 are filter capacitors at the output of the three-phase rectifier. The input terminals VIN+ and VIN- of the high-voltage DC-DC module are connected to the positive DC power supply DCOUT+ and the negative DC power supply DCOUT-, respectively; the output terminals VOUT+ and VOUT- of the high-voltage DC-DC module output the positive DC power supply DC1+ and the negative DC power supply DC1-, respectively. The DC output detection module includes a high-voltage divider VR1, an isolation amplifier A4, a filter F2, and an analog-to-digital converter ADC4. The high-voltage divider VR1 is connected to the positive power supply DC1+ and is used to divide the positive power supply DC1+ to obtain the voltage acquisition signal of the high-voltage DC power supply. The voltage acquisition signal is input to the input terminal of the isolation amplifier A4. The output terminal of the isolation amplifier A4 is connected to the filter F2. The filter F2 is connected to the analog-to-digital converter ADC4. The analog-to-digital converter ADC4 is connected to the main controller.

7. A portable isolation test power supply as described in claim 6, characterized in that: The high-voltage DC-DC module is model XPPowerHVM12-1000; the high-voltage divider VR1 is a voltage divider composed of multiple high-voltage resistors connected in series; the isolation amplifier A4 is model AMC1301B; the filter F2 is an RC low-pass filter network; and the analog-to-digital converter ADC4 is model ADS1115.

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