High-power impedance and current-carrying capacity testing device and method

Abstract

The invention discloses a high-power impedance and current-carrying capacity testing device and method, and relates to the technical field of impedance and current-carrying capacity testing. The device comprises an input protection module, a self-coupling adjustable transformer, a mode switching module, a current boosting transformer, an alternating current and direct current switching module, a sampling module, a signal processing and control module, a system display module and a device control panel. According to the invention, input protection-voltage control-mode switching-voltage adjustment-AC / DC conversion-parameter measurement and control are taken as the core work flow of the test device, and through electrical connection of the modules, safe conversion of an external power supply and stable and accurate adjustment and output of test voltage and current are realized. The device has the functions of impedance testing and current-carrying capability testing.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of impedance and current-carrying capacity testing, in particular to a high-power impedance and current-carrying capacity testing device and method. BACKGROUND

[0002] For permanently installed medical electrical equipment, the impedance and current-carrying capacity between its protective earth terminal and any protective earthed component need to be tested. According to the GB 9706.1 standard, a test current is usually generated by using an industrial frequency AC current source or a DC current source, and the test current is circulated between the protective earth terminal or the protective earth point of the appliance input socket or the protective earth pin of the mains plug and each protective earthed component for a time required by the standard, and the voltage drop between the components is measured to determine the impedance according to the current and the voltage drop. If the measured impedance is within the allowable limit, the impedance measurement is repeated using a current source with a sufficiently large no-load voltage to inject a specified current in the total impedance to confirm their current-carrying capacity.

[0003] However, the voltage and current ranges required for impedance testing and current-carrying capacity testing are significantly different, and traditionally two sets of devices, a dedicated impedance tester and an independent high-power current-carrying device, are required to complete the test. This separate scheme results in frequent equipment replacement and re-wiring during the test process, which not only is cumbersome and inefficient, but also may cause poor correlation of test data due to the difficulty in maintaining consistent contact states (such as different clamping forces) between the two connections, making it difficult to accurately establish the correspondence between "impedance-current-carrying capacity", and failing to meet the implicit requirements of the standard for systematic and consistent evaluation of the performance of the equipment protective grounding system.

[0004] In addition, existing current-carrying capacity testing devices generally have the problems of wide test range but insufficient targeting, weak anti-interference ability, chaotic application scenarios, and high equipment cost, etc. in order to accommodate the wide test parameters of industrial equipment. When high-power output is required, the control circuit is easily disturbed by external factors, resulting in deviations in test results. The specific problems are as follows: 1. The power switching element, as the core component of the test system, has a complex coupling relationship between switching frequency, conduction current and loss, which affects the service time and test current range of the test device; 2. Electromagnetic interference: In complex electromagnetic environments such as industrial workshops, the high-frequency electromagnetic fields generated by surrounding equipment can induce stray voltages in the test loop, directly causing measurement value deviations; 3. Environmental factor interference: In humid or dusty environments, the contact resistance between the test pen and the grounding terminal is unstable, which can further amplify the test error; 4. Precision and cost contradiction: the existing equipment can only ensure the test precision in the ideal laboratory environment, and the error rate of on-site test can reach more than 10%, which cannot meet the use demand of medical equipment with strict precision requirement; and in order to solve the above interference problem, high cost optimization equipment is often needed, resulting in poor economy; 5. Frequent plugging operation, the switching board and supporting control software that can switch the test network need to be developed, and the test efficiency is not high.

[0005] Therefore, it has extremely important practical significance and application value to develop a high-power impedance and current-carrying capacity test equipment which meets the GB 9706.1 standard, integrates impedance and current-carrying capacity test functions, has wide test range, high test precision, strong anti-interference ability and perfect safety protection. SUMMARY

[0006] In view of the above defects or deficiencies in the prior art, the present application provides a high-power impedance and current-carrying capacity test device and method, which realizes the deep integration of impedance test and current-carrying capacity test in a single device.

[0007] In one aspect, the present application provides a high-power impedance and current-carrying capacity test device, comprising: An input protection module for connecting an external power supply and providing overcurrent, overload and short circuit protection; A self-coupled adjustable transformer comprising a primary winding and a secondary winding, the primary winding being connected to the input protection module for continuous adjustment of test voltage; a current boosting transformer comprising at least two primary windings and a secondary winding for increasing the test current range; A mode switching module, the input end of which is connected to the secondary winding of the self-coupled adjustable transformer, and the output end of which is connected to the primary winding of the current boosting transformer, for switching the first primary winding or the second primary winding of the current boosting transformer through a first switching switch to switch the impedance test mode and the current-carrying capacity test mode; An AC / DC switching module, the input end of which is connected to the secondary winding of the current boosting transformer, and the output end of which is used as the output end of the test device for outputting test voltage and test current; the AC / DC switching module is used for switching the AC test mode and the DC test mode through a second switching switch; A sampling module for collecting the test voltage and test current output by the AC / DC switching module; A signal processing and control module for calculating the target impedance data of the measured target according to the test voltage and test current collected by the sampling module, and controlling the self-coupled adjustable transformer to adjust the test voltage and test current.

[0008] Furthermore, the mode switching module includes a first switching switch, a first circuit breaker, a first AC contactor, a second circuit breaker, and a second AC contactor; The common terminal of the first switching switch serves as the input terminal of the mode switching module and is connected to the secondary winding of the autotransformer. The first stationary contact of the first switching switch is sequentially connected to the first circuit breaker, the first AC contactor, and the first primary winding of the current-boosting transformer. When the common terminal of the first switching switch is connected to the first stationary contact of the first switching switch, it switches to impedance test mode. The second stationary contact of the first switching switch is sequentially connected to the second circuit breaker, the second AC contactor, and the second primary winding of the current-boosting transformer. When the common terminal of the first switching switch is connected to the second stationary contact of the first switching switch, it switches to the current-carrying capacity test mode.

[0009] Furthermore, the AC / DC switching module includes a second switching switch and a full-bridge rectifier module, wherein the full-bridge rectifier module is used to convert AC power into DC power; The common terminal of the second switching switch serves as the input terminal of the AC / DC switching module and is connected to the secondary winding of the current-boosting transformer. When the first stationary contact of the second switching switch is connected to the full-bridge rectifier module, and the common terminal of the second switching switch is connected to the first stationary contact of the second switching switch, it switches to DC test mode and outputs DC test current and DC test voltage. When the common terminal of the second switching switch is connected to the second stationary contact of the second switching switch, it switches to AC test mode and outputs AC test current and AC test voltage.

[0010] Furthermore, the sampling module includes a first current measurement sensor, a first voltage measurement sensor, a second current measurement sensor, and a second voltage measurement sensor. The first current measurement sensor and the first voltage measurement sensor are used to measure the DC test current and the DC test voltage, respectively, and the second current measurement sensor and the second voltage measurement sensor are used to measure the AC test current and the AC test voltage, respectively.

[0011] Furthermore, the primary winding of the current-boosting transformer is connected in a delta configuration, and the secondary winding is connected in a star configuration. The neutral point of the secondary winding is isolated and connected to an external grounding system.

[0012] Furthermore, the current-boosting transformer has a built-in temperature switch, which is respectively located in the primary winding, secondary winding and core of the current-boosting transformer. When the temperature of the current-boosting transformer exceeds a preset threshold, the input power is cut off.

[0013] Furthermore, the signal processing and control module also includes a first time relay and a second time relay. The first time relay is connected to the first AC contactor, and the second time relay is connected to the second AC contactor. The first time relay and the second time relay are used to control the overall test time. When the test process reaches the preset test time, the time relay cuts off the coil power supply of the AC contactor.

[0014] Furthermore, the signal processing and control module is housed within a sealed metal box.

[0015] Furthermore, it also includes: The system display module, connected to the signal processing and control module, is used to display the output test voltage, test current, and impedance data of the target under test. The device control panel, connected to the signal processing and control module, is used by the user to select impedance test mode or current carrying capacity test mode, AC test mode or DC test mode, and input test voltage or test current settings.

[0016] Another aspect of the present invention provides a test method for the high-power impedance and current-carrying capacity test apparatus described in any one of the above claims, comprising: Connect the external power supply to the input terminal of the test device, connect the target under test to the output terminal of the test device, and select the impedance test mode or current carrying capacity test mode, AC test mode or DC test mode, set the test voltage or test current and set the test time through the device control panel. The signal processing and control module controls the first switching switch of the mode switching module to switch between impedance test mode and current carrying capacity test mode according to the instructions of the control panel of the device, and controls the second switching switch of the AC / DC switching module to switch between AC test mode and DC test mode. External power is fed into the autotransformer via the input protection module. The output voltage of the autotransformer is fed into the boost transformer via the mode switching module. The boost transformer increases the output current. The AC / DC switching module then outputs AC test voltage and AC test current or DC test voltage and DC test current. The sampling module collects test voltage and test current in real time and transmits them to the signal processing and control module. The signal processing and control module calculates the impedance data of the target under test based on the test voltage and test current, and transmits the test voltage, test current and impedance data to the system display module for display. The signal processing and control module continuously adjusts the output voltage of the autotransformer based on the collected test voltage and test current until the test voltage and test current reach the set values. Once the test time reaches the set value, the signal processing and control module automatically cuts off the power supply to the AC contactor coil in the mode switching module via a time relay to disconnect the power supply to the target under test, thus completing the test.

[0017] This invention provides a device and method for testing high-power impedance and current-carrying capacity, which mainly has the following beneficial effects: (1) This device adopts a composite design of autotransformer and current booster transformer. The control circuit adjusts the autotransformer based on the test set value and feedback data to achieve continuous and accurate adjustment of test voltage and current, which meets the voltage requirements of the test device for different test targets and different test scenarios. With the help of the mode switching module, it can reliably and quickly switch between two test modes by simply operating the switching switch. This solves the problems of complicated operation, inconsistent wiring status and poor data correlation caused by using two independent devices in the traditional solution, and ensures the consistency of test conditions and the accuracy of results. (2) This device has achieved remarkable results in improving test accuracy and anti-interference capability. The current-boosting transformer adopts a connection method of delta connection of primary winding and star connection of secondary winding, which provides a stable reference potential for high-precision measurement and effectively suppresses harmonic interference. The signal processing and control module is placed in a closed metal box to avoid the influence of electromagnetic interference and ensure that high-precision measurement can still be achieved in complex industrial electromagnetic environment; (3) This device has a complete multi-layer safety protection mechanism. The system integrates time relay, embedded temperature switch and overcurrent protection circuit, realizing real-time monitoring and protection of test time, transformer temperature rise and loop current, effectively preventing equipment damage and safety hazards caused by test timeout, overheating or overcurrent, and greatly improving the reliability and service life of the equipment under high power test.

[0018] This invention uses "input protection - voltage control - mode switching - voltage adjustment - AC / DC conversion - parameter measurement and control" as the core workflow of the testing device. Through the electrical connection of each module, it realizes the safe conversion of external power supply and the stable and accurate adjustment and output of test voltage and current, which meets the test requirements of GB 9706.1. It also has the functions of impedance testing and current carrying capacity testing, wide test current and voltage range, strong anti-interference ability, high test accuracy and comprehensive safety protection, providing a new solution for compliance testing in fields such as medical electrical equipment. Attached Figure Description

[0019] Other features, objects, and advantages of this application will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings: Figure 1This is a circuit diagram of a high-power impedance and current-carrying capacity testing device provided in one embodiment of this application; Figure 2 This is a schematic diagram of the structure of a high-power impedance and current-carrying capacity testing device provided in one embodiment of this application.

[0020] in: 1-Input protection module; 2-Autotransformer; 3-Mode switching module; 4-Current booster transformer; 5-AC / DC switching module; 6-Sampling module; 7-Signal processing and control module; 8-System display module; 9-Device control panel; K1-First switching switch; CB1-First circuit breaker; KM1-First AC contactor; CB2-Second circuit breaker; KM2-Second AC contactor; KT1-First time relay; KT2-Second time relay; K2-Second switching switch; 51-Full-bridge rectifier module; A1-First current measurement sensor; V1-First voltage measurement sensor; A2-Second current measurement sensor; V2-Second voltage measurement sensor. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, 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, 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.

[0022] The terminology used in the embodiments of this invention is for the purpose of describing particular embodiments only and is not intended to limit the invention. The singular forms “a,” “the,” and “the” used in the embodiments of this invention are also intended to include the plural forms unless the context clearly indicates otherwise.

[0023] It should be understood that although the terms first, second, third, etc., may be used to describe the acquisition modules in the embodiments of the present invention, these acquisition modules should not be limited to these terms. These terms are only used to distinguish the acquisition modules from each other.

[0024] Depending on the context, the word "if" as used here can be interpreted as "when," "when," "in response to determination," or "in response to detection." Similarly, depending on the context, the phrase "if determination" or "if detection (of the stated condition or event)" can be interpreted as "when determination," "in response to determination," "when detection (of the stated condition or event)," or "in response to detection (of the stated condition or event)."

[0025] It should be noted that the directional terms such as "upper," "lower," "left," and "right" used in the embodiments of the present invention are used to describe the angles shown in the accompanying drawings and should not be construed as limiting the embodiments of the present invention. Furthermore, in the context, it should be understood that when it is mentioned that an element is formed "upper" or "lower" of another element, it can not only be formed directly "upper" or "lower" of the other element, but also indirectly "upper" or "lower" of the other element through an intermediate element.

[0026] refer to Figure 1 This invention provides a high-power impedance and current-carrying capacity testing device, comprising: an input protection module 1, an autotransformer 2, a mode switching module 3, a current-boosting transformer 4, an AC / DC switching module 5, a sampling module 6, a signal processing and control module 7, a system display module 8, and a device control panel 9.

[0027] Specifically, the input protection module 1 is used to connect to an external power supply and provide overcurrent, overload and short circuit protection. For example, the input protection module 1 adopts a circuit breaker or a contactor.

[0028] The autotransformer 2 includes a primary winding and a secondary winding. The primary winding is connected to the input protection module 1 for continuous adjustment of the test voltage. The current-boosting transformer 4 includes at least two primary windings and a secondary winding. For example, in the test device provided in this embodiment, the current-boosting transformer 4 includes a first primary winding, a second primary winding, and a secondary winding. It is connected to the autotransformer 2 through the mode switching module 3 to improve the test current range. The primary winding of the current-boosting transformer 4 adopts a delta connection, and the secondary winding adopts a star connection. The neutral point of the secondary winding is isolated and connected to an external grounding system. The current-boosting transformer 4 has a built-in temperature switch, which is set at the primary winding, secondary winding, and core of the current-boosting transformer 4. When the temperature of the current-boosting transformer 4 exceeds a preset threshold, the input power is cut off to achieve over-temperature protection.

[0029] The input terminal of the mode switching module 3 is connected to the secondary winding of the autotransformer 2, and its output terminal is connected to the primary winding of the current-boosting transformer 4. It is used to switch the connection between the first primary winding or the second primary winding of the current-boosting transformer 4 through the first switching switch K1, so as to switch the impedance test mode and the current-carrying capacity test mode. Specifically, the mode switching module 3 includes a first switching switch K1, a first circuit breaker CB1, a first AC contactor KM1, a second circuit breaker CB2, and a second AC contactor KM2; The common terminal of the first switching switch K1 serves as the input terminal of the mode switching module 3 and is connected to the secondary winding of the autotransformer 2. The first stationary contact of the first switching switch K1 is connected in sequence to the first circuit breaker CB1, the first AC contactor KM1 and the first primary winding of the current-boosting transformer 4. When the common terminal of the first switching switch K1 is connected to the first stationary contact of the first switching switch, it switches to impedance test mode. The second stationary contact of the first switching switch K1 is connected in sequence to the second circuit breaker CB2, the second AC contactor KM2 and the second primary winding of the current-boosting transformer 4. When the common terminal of the first switching switch K1 is connected to the second stationary contact of the first switching switch, it switches to the current-carrying capacity test mode.

[0030] The AC / DC switching module 5 has its input terminal connected to the secondary winding of the current-boosting transformer 4, and its output terminal serves as the output terminal of the test device for outputting test voltage and test current. The AC / DC switching module 5 is used to switch between AC test mode and DC test mode via the second switching switch K2. Specifically, the AC / DC switching module 5 includes a second switching switch K2 and a full-bridge rectifier module 51, which is used to convert AC power into DC power. The common terminal of the second switching switch K2 serves as the input terminal of the AC / DC switching module 5 and is connected to the secondary winding of the boost transformer 4. The first stationary contact of the second switching switch K2 is connected to the full-bridge rectifier module 51. When the common terminal of the second switching switch K2 is connected to the first stationary contact of the second switching switch K2, it switches to DC test mode and outputs DC test current and DC test voltage. When the common terminal of the second switching switch K2 is connected to the second stationary contact of the second switching switch K2, it switches to AC test mode and outputs AC test current and AC test voltage.

[0031] Sampling module 6 is used to collect the test voltage and test current output by AC / DC switching module 5; Specifically, the sampling module 6 includes a current measurement sensor A1, a voltage measurement sensor V1, a current measurement sensor A2, and a voltage measurement sensor V2. The current measurement sensor A1 and the voltage measurement sensor V1 are used to measure the DC test current and DC test voltage output by the AC / DC switching module 5, respectively. The current measurement sensor A2 and the voltage measurement sensor V2 are used to measure the AC test current and AC test voltage output by the AC / DC switching module 5, respectively.

[0032] The signal processing and control module 7 is used to calculate the impedance data of the target under test based on the test voltage and test current collected by the sampling module 6, and to control the autotransformer 2 based on the test setpoint and the feedback data collected by the sampling module 6 to continuously adjust the test voltage and test current output by the test device until the user-preset test voltage or test current is reached. The signal processing and control module 7 controls the first switching switch K1 connected to control the mode switching module 3 according to the test requirements, realizing the switching between impedance test mode and current carrying capacity test. The signal processing and control module 7 also includes time relays KT1 and KT2. Time relay KT1 is connected to AC contactor KM1, and time relay KT2 is connected to AC contactor KM2. Time relays KT1 and KT2 are used to control the overall test time. When the test process reaches the preset test time, the time relays cut off the power supply to the AC contactor coil. The signal processing and control module 7 controls the second switching switch K2 according to the test requirements to control the AC / DC switching module 5, realizing the switching between AC test mode and DC test mode. In addition, the signal processing and control module 7 is placed in a closed metal box to avoid the influence of electromagnetic interference.

[0033] The system display module 8 is connected to the signal processing and control module 7 and is used to display the output test voltage, test current and the impedance data of the target under test.

[0034] The device control panel 9 is connected to the signal processing and control module 7. It is used by the user to select the impedance test mode or current carrying capacity test mode, AC test mode or DC test mode, and set the input test voltage or test current. After the user selects the test mode and sets the test voltage or test current according to the target being tested, the signal processing and control module 7 realizes precise control of the output test voltage and test current.

[0035] The working principle of this invention is as follows: The present invention provides a high-power impedance and current-carrying capacity testing device, which takes "input protection - voltage control - mode switching - voltage adjustment - AC / DC conversion - parameter measurement and control" as its core workflow. Through the electrical connection of each module, it realizes the safe conversion of external power supply and the stable and accurate adjustment and output of test voltage and test current. After the external power supply is connected through the input protection module, it first enters the autotransformer for continuous voltage regulation, providing a precise input voltage for subsequent circuits. This voltage is then sent to the mode switching module, which selects to connect different primary windings of the booster transformer via a switching switch: connecting the first primary winding activates the impedance test mode, while connecting the second winding activates the current carrying capacity test mode. The booster transformer converts the input voltage from the previous stage into the large current required for the test. Subsequently, the AC / DC switching module selects to directly output AC test voltage and test current, or output DC test voltage and test current through the full-bridge rectifier module. The sensors at the output of the test device collect the output test voltage and test current signals in real time and feed them back to the signal processing and control module, which automatically calculates the impedance data of the target under test and displays it in real time. The entire process is precisely controlled by the time relay within the signal processing and control module to ensure that the power is automatically cut off after the set time is reached. Combined with multiple protection mechanisms such as the temperature switch built into the booster transformer, the safe and stable operation of the equipment under high-power testing is guaranteed.

[0036] This invention provides a high-power impedance and current-carrying capacity testing device. It employs a composite design of an autotransformer and a current-boosting transformer, combined with a mode-switching module. This allows for reliable and rapid switching between impedance and current-carrying capacity testing modes simply by operating a switching switch, effectively solving the problems of cumbersome operation, inconsistent wiring, and poor data correlation caused by traditional solutions using two independent devices. Regarding improved testing accuracy and anti-interference capabilities, the current-boosting transformer effectively suppresses harmonic interference through a specific winding connection method. Simultaneously, the signal processing and control modules are housed in a sealed metal box, significantly reducing electromagnetic interference and ensuring high-precision measurements even in complex industrial environments. Furthermore, the device integrates multiple safety protection mechanisms, including a time relay, an embedded temperature switch, and an overcurrent protection circuit. It can monitor test time, transformer temperature rise, and loop current in real time, effectively preventing damage due to timeouts, overheating, or overcurrent, greatly improving the reliability and lifespan of the device under high-power testing. This device has a wide testing current and voltage range, meets the testing requirements of GB 9706.1, and provides an integrated solution that is easy to operate, accurate, reliable and safe for compliance testing in fields such as medical electrical equipment.

[0037] This invention also provides a testing method for the high-power impedance and current-carrying capacity testing device described in any one of the above embodiments, comprising: Connect the external power supply to the input terminal of the test device, connect the target under test to the output terminal of the test device, and select the impedance test mode or current carrying capacity test mode, AC test mode or DC test mode, set the test voltage or test current and set the test time through the device control panel. The signal processing and control module controls the first switching switch of the mode switching module to switch between impedance test mode and current carrying capacity test mode according to the instructions of the control panel of the device, and controls the second switching switch of the AC / DC switching module to switch between AC test mode and DC test mode. External power is fed into the autotransformer via the input protection module. The output voltage of the autotransformer is fed into the boost transformer via the mode switching module. The boost transformer increases the output current, and then the AC / DC switching module outputs the test voltage and test current. The sampling module collects test voltage and test current in real time and transmits them to the signal processing and control module. The signal processing and control module calculates the impedance data of the target under test based on the test voltage and test current, and transmits the test voltage, test current and impedance data to the system display module for display. The signal processing and control module continuously adjusts the autotransformer based on the collected test voltage and test current until the test voltage and test current reach the set values. Once the test time reaches the set value, the signal processing and control module automatically cuts off the power supply to the AC contactor coil in the mode switching module via a time relay to disconnect the power supply to the target under test, thus completing the test.

[0038] For example, users can perform impedance testing or current-carrying capacity testing using the testing apparatus provided in the above embodiments, according to GB 9706.1, including: Impedance test: Connect the target to be tested to the output terminal of the test device, select the impedance test mode through the device control panel, and set the test voltage and test time. For example, set the test voltage to 6V and the test time to 5S. When the test is started, the target under test is automatically powered on, and the test device monitors and displays the test current and impedance data in real time. When the test time reaches the set 5 seconds, the test device automatically cuts off the power supply to the target under test, completing the impedance test.

[0039] Current carrying capacity test: Connect the target under test to the output terminal of the test device, select the current carrying capacity test mode through the device control panel, and set the test current and test time. The test current value is calculated according to "rated current × 1.5" and set accordingly. The test time is set within the range of 5S~10S based on the actual characteristics of the target under test and the test requirements. When the test is started, the target under test is automatically powered on, the test current flows normally inside the target under test, and the test device collects and displays the test voltage and impedance data in real time. Based on the changes in the data, it can determine whether there are any abnormalities such as voltage drop or impedance change. When the test time reaches the set value, the test device automatically cuts off the power supply to the target under test, thus completing the current carrying capacity test.

[0040] When switching between impedance test mode and current carrying capacity test mode, after the previous test mode is completed and the test device automatically cuts off the power supply to the target under test, the user can directly select another test mode through the device control panel after confirming that the test device is powered off. When all tests are completed, the power supply of the test device is turned off.

[0041] The above description is merely a preferred embodiment of the present invention. Those skilled in the art should understand that the scope of disclosure in this invention is not limited to the specific combination of the above-described technical features, but should also cover other technical solutions formed by any combination of the above-described technical features or their equivalents without departing from the above-described concept. For example, technical solutions formed by substituting the above features with (but not limited to) technical features with similar functions disclosed in this invention.

Claims

1. A high-power impedance and current-carrying capacity testing device, characterized in that, include: The input protection module is used to connect to an external power supply and provide overcurrent, overload and short circuit protection; An autotransformer includes a primary winding and a secondary winding, the primary winding being connected to the input protection module for continuously adjusting the test voltage; a current-boosting transformer includes at least two primary windings and a secondary winding for increasing the test current range. The mode switching module has its input end connected to the secondary winding of the autotransformer and its output end connected to the primary winding of the current-boosting transformer. It is used to switch the connection between the first primary winding or the second primary winding of the current-boosting transformer through the first switching switch, so as to switch the impedance test mode and the current-carrying capacity test mode. An AC / DC switching module has its input terminal connected to the secondary winding of the current-boosting transformer, and its output terminal serving as the output terminal of the testing device for outputting test voltage and test current; the AC / DC switching module is used to switch between AC test mode and DC test mode via a second switching switch. The sampling module is used to collect the test voltage and test current output by the AC / DC switching module; The signal processing and control module is used to calculate the impedance data of the target under test based on the test voltage and test current collected by the sampling module, and to control the autotransformer to adjust the test voltage and test current.

2. The high-power impedance and current-carrying capacity testing device according to claim 1, characterized in that, The mode switching module includes a first switching switch, a first circuit breaker, a first AC contactor, a second circuit breaker, and a second AC contactor. The common terminal of the first switching switch serves as the input terminal of the mode switching module and is connected to the secondary winding of the autotransformer. The first stationary contact of the first switching switch is sequentially connected to the first circuit breaker, the first AC contactor, and the first primary winding of the current-boosting transformer. When the common terminal of the first switching switch is connected to the first stationary contact of the first switching switch, it switches to impedance test mode. The second stationary contact of the first switching switch is sequentially connected to the second circuit breaker, the second AC contactor, and the second primary winding of the current-boosting transformer. When the common terminal of the first switching switch is connected to the second stationary contact of the first switching switch, it switches to the current-carrying capacity test mode.

3. The high-power impedance and current-carrying capacity testing device according to claim 1, characterized in that, The AC / DC switching module includes a second switching switch and a full-bridge rectifier module, wherein the full-bridge rectifier module is used to convert AC power into DC power; The common terminal of the second switching switch serves as the input terminal of the AC / DC switching module and is connected to the secondary winding of the current-boosting transformer. When the first stationary contact of the second switching switch is connected to the full-bridge rectifier module, and the common terminal of the second switching switch is connected to the first stationary contact of the second switching switch, it switches to DC test mode and outputs DC test current and DC test voltage. When the common terminal of the second switching switch is connected to the second stationary contact of the second switching switch, it switches to AC test mode and outputs AC test current and AC test voltage.

4. The high-power impedance and current-carrying capacity testing device according to claim 3, characterized in that, The sampling module includes a first current measurement sensor, a first voltage measurement sensor, a second current measurement sensor, and a second voltage measurement sensor. The first current measurement sensor and the first voltage measurement sensor are used to measure the DC test current and the DC test voltage, respectively. The second current measurement sensor and the second voltage measurement sensor are used to measure the AC test current and the AC test voltage, respectively.

5. The high-power impedance and current-carrying capacity testing device according to claim 2, characterized in that, The primary winding of the current-boosting transformer is connected in a delta configuration, and the secondary winding is connected in a star configuration. The neutral point of the secondary winding is isolated and connected to an external grounding system.

6. The high-power impedance and current-carrying capacity testing device according to claim 5, characterized in that, The current booster transformer has a built-in temperature switch, which is respectively located on the primary winding, secondary winding and core of the current booster transformer. When the temperature of the current booster transformer exceeds a preset threshold, the input power is cut off.

7. The high-power impedance and current-carrying capacity testing device according to claim 2, characterized in that, The signal processing and control module further includes a first time relay and a second time relay. The first time relay is connected to the first AC contactor, and the second time relay is connected to the second AC contactor. The first time relay and the second time relay are used to control the overall test time. When the test process reaches the preset test time, the time relay cuts off the coil power supply of the AC contactor.

8. The high-power impedance and current-carrying capacity testing device according to claim 7, characterized in that, The signal processing and control module is housed in a sealed metal box.

9. The high-power impedance and current-carrying capacity testing device according to claim 1, characterized in that, Also includes: The system display module, connected to the signal processing and control module, is used to display the output test voltage, test current, and impedance data of the target under test. The device control panel, connected to the signal processing and control module, is used by the user to select impedance test mode or current carrying capacity test mode, AC test mode or DC test mode, and input test voltage or test current settings.

10. A test method for the high-power impedance and current-carrying capacity test apparatus according to any one of claims 1-8, characterized in that, include: Connect the external power supply to the input terminal of the test device, connect the target under test to the output terminal of the test device, and select the impedance test mode or current carrying capacity test mode, AC test mode or DC test mode, set the test voltage or test current and set the test time through the device control panel. The signal processing and control module controls the first switching switch of the mode switching module to switch between impedance test mode and current carrying capacity test mode according to the instructions of the control panel of the device, and controls the second switching switch of the AC / DC switching module to switch between AC test mode and DC test mode. External power is fed into the autotransformer via the input protection module. The output voltage of the autotransformer is fed into the boost transformer via the mode switching module. The boost transformer increases the output current, and then the AC / DC switching module outputs the test voltage and test current. The sampling module collects test voltage and test current in real time and transmits them to the signal processing and control module. The signal processing and control module calculates the impedance data of the target under test based on the test voltage and test current, and transmits the test voltage, test current and impedance data to the system display module for display. The signal processing and control module continuously adjusts the autotransformer based on the collected test voltage and test current until the test voltage and test current reach the set values. Once the test time reaches the set value, the signal processing and control module automatically cuts off the power supply to the AC contactor coil in the mode switching module via a time relay to disconnect the power supply to the target under test, thus completing the test.

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