Long-duration impulse current test system and method based on power electronic chopping

Abstract

The invention discloses a long-duration impulse current test system and method based on power electronic chopping, the chopping time is controlled through a program, a long-duration impulse current with controllable regulation of 5-100ms and controllable reversal of polarity is output, a power supply is directly connected with a voltage-regulating constant-current direct-current charging unit, and the voltage-regulating constant-current direct-current charging unit is connected with a direct-current charging unit. Continuously adjusted charging voltage is output through the voltage-adjusting constant-current direct-current charging unit, and the charging voltage is transmitted to the energy storage capacitor unit; the low-voltage end of the energy storage capacitor unit is grounded through a grounding wire, and the high-voltage end of the energy storage capacitor unit outputs impact energy released by the energy storage capacitor unit to the rectifying and filtering unit; the rectifying and filtering unit rectifies the impact energy into direct-current energy and outputs the direct-current energy to the power electronic chopping unit; and the power electronic chopping unit is used for cutting the direct current energy into direct current with preset wavelength and preset polarity by controlling the on-off time, so that the waveform of the output current meets the test requirement.

Description

Technical Field

[0001] The present invention relates to the technical field of high-voltage electrical test equipment, and more specifically, to a long-duration impulse current test system and method based on power electronic chopping. Background Art

[0002] Long-duration impulse current test is usually used to simulate the operating impulse energy and short-circuit fault energy of long transmission lines, verify the current carrying capacity of lightning arresters, and is a type test, periodic test and sampling test item in the national standard for lightning arresters. It is used to screen resistors and verify the repeated transfer charge tolerance of resistors. Long-duration impulse current usually uses a waveform with a wavelength of 2ms or 4ms, but for lightning arresters used in UHV DC projects, such as neutral busbar lightning arresters and DC transfer switch lightning arresters, they may be subjected to overvoltage energy with a wavelength of 50ms or even 100ms during operating conditions. At this time, it is necessary to simulate the actual operating conditions to verify the current carrying capacity of the lightning arrester.

[0003] There are many ways to implement the test circuit for μs-level impulse current, such as RLC discharge circuit or Crowbar discharge circuit that uses gap-type Crowbar switch to extend the wave tail. However, the long-duration impulse current of ms level is usually implemented by LC concentrated parameter chain circuit, which adopts single chain and multi-chain combination, and outputs the required impulse waveform and current by changing the capacitor and inductor wiring method. This circuit mode requires a large number of impulse capacitors and inductors. Due to factors such as space limitations, the number of chains in the existing test circuit usually does not exceed 4, and the output impulse current wavelength does not exceed 10ms, making it difficult to output impulse currents as long as 50ms or even 100ms; when adjusting the waveform, it is necessary to manually increase or decrease the number of capacitors and inductors, which makes the wave modulation complicated, and if the capacitor is not thoroughly discharged after grounding, there will be safety risks when manually adjusting the wave; the inductance value of a single inductor is large, and a large electric force will be generated when a high-amplitude impulse current passes through it, which is prone to loosening, disconnection and other damage during long-term use.

[0004] Therefore, a technology is needed to realize long duration impulse current test based on power electronic chopping. Summary of the invention

[0005] The technical solution of the present invention provides a long-duration impulse current test system and method based on power electronic chopping to solve the problem of how to perform a long-duration impulse current test based on power electronic chopping.

[0006] In order to solve the above problems, the present invention provides a long-duration impulse current test system based on power electronic chopper, the system comprising: a voltage-regulated constant-current DC charging unit, an energy storage capacitor unit, a rectifier and filter unit, and a power electronic chopper unit connected in sequence;

[0007] The power supply is directly connected to the voltage-regulated constant-current DC charging unit, outputs a continuously adjusted charging voltage through the voltage-regulated constant-current DC charging unit, and transmits the charging voltage to the energy storage capacitor unit;

[0008] The low-voltage end of the energy storage capacitor unit is grounded through a grounding wire, and the high-voltage end of the energy storage capacitor unit outputs the impact energy released by the energy storage capacitor unit to the rectification and filtering unit;

[0009] The rectifying and filtering unit rectifies the impact energy into DC energy, and outputs the DC energy to the power electronic chopper unit;

[0010] The power electronic chopper unit is used to cut the DC energy into a DC current of a preset wavelength and a preset polarity by controlling the breaking time, so that the output current waveform meets the test requirements.

[0011] Preferably, the voltage-regulated constant-current DC charging unit adopts a voltage-doubling rectifier constant-current charging method to convert the 380V three-phase electricity of the power supply into a charging voltage of a predetermined value; the voltage-regulated constant-current DC charging unit controls the polarity through a thyristor and adopts a single-phase column electric voltage regulator to track the voltage regulation to achieve constant-current charging; a charging protection resistor is provided on the high-voltage side of the voltage-regulated constant-current DC charging unit, and a series protection resistor is provided on the low-voltage side.

[0012] Preferably, the energy storage capacitor unit is connected in parallel through multiple groups of capacitors, the maximum charging voltage is 60kV, and the maximum output energy is 864kJ; the impact energy output by the energy storage capacitor unit is generated according to the charging voltage, and the discharge time of the energy storage capacitor unit is in the ms level.

[0013] Preferably, the rectifying and filtering unit comprises power electronic components such as thyristors and inductance components, and rectify the impact energy released by the capacitor unit when triggered into DC energy through rectification and filtering.

[0014] Preferably, the power electronic chopper unit is used to break the forward and reverse current of 10kA, and the breaking time is within 5ms; the power electronic chopper unit includes a main branch, a transfer branch and an absorption branch; the main branch is used to bear the overvoltage at both ends of the DC-DC converter when the normal working current and the fault current are broken, and to realize the bidirectional conduction of the DC circuit; the transfer branch is used to generate an oscillating current in the opposite direction to the main branch current, and superimpose the reverse oscillating current on the main branch to force the fault current on the main branch to pass through zero, and transfer the fault current from the main branch to the transfer branch; the absorption branch is used to absorb and discharge the energy accumulated during fault breaking.

[0015] The breaking time is controlled by computer program so that the output current waveform meets the test requirements. The breaking time can be arbitrarily controlled within 5ms to 100ms.

[0016] Preferably, the system further comprises a grounding loop consisting of a discharge resistor and a grounding switch, wherein the discharge resistor is a high voltage resistor with a resistance value of 20 kΩ; and the grounding switch is used for emergency stop by leading out a control switch.

[0017] Preferably, it also includes: the system also includes an impact resistor divider connected in parallel to both ends of the test sample, the test sample is connected in series with the impact current loop and then connected in parallel to the power electronic chopper unit and the grounding wire; the impact resistor divider is a resistive voltage divider with a rated voltage of 30kV and an accuracy of 1%; the wave response time of the impact resistor divider is not more than 20ns, and the transformation ratio is 100V / V.

[0018] Preferably, it also includes a sample operating table, which is an aluminum alloy profile and has a test station, and the sample is set on the test station;

[0019] An epoxy protection plate is installed around the test station, and the test sample is clamped by a pneumatic mechanism so that the test sample is in close contact with the electrodes of the test station.

[0020] Preferably, the impulse current measuring coil is a Rogowski coil with a transformation ratio of 100A / V.

[0021] Preferably, the voltage-regulated constant-current DC charging unit is also connected to a second energy storage capacitor unit, a second rectifier and filter unit, and a second power electronic chopper unit;

[0022] The voltage-regulated constant-current DC charging unit transmits the charging voltage to the second energy storage capacitor unit;

[0023] The high-voltage end of the second energy storage capacitor unit outputs the impact energy released by the second energy storage capacitor unit to the second rectifier and filter unit;

[0024] The second rectifying and filtering unit rectifies the impact energy into direct current energy, and outputs the direct current energy to the second power electronic chopper unit.

[0025] By changing the charging polarity, an impact current of another polarity is output, and the output time of the second power electronic chopper unit is controlled by a computer program, and used in conjunction with the first power electronic chopper unit, an impact current with reversed polarity is output.

[0026] According to another aspect of the present invention, the present invention provides a method for performing an impulse current test based on the above test system, the method comprising:

[0027] Outputting a continuously adjusted charging voltage through the voltage-regulated constant-current DC charging unit, and transmitting the charging voltage to the energy storage capacitor unit;

[0028] Releasing the impact energy through the energy storage capacitor unit and outputting the impact energy to the rectification and filtering unit;

[0029] Rectifying the impact energy into DC energy through the rectifying and filtering unit, and outputting the DC energy to the power electronic chopper unit;

[0030] The DC energy is cut into a DC current of a preset wavelength by the power electronic chopper unit, and the DC current is applied to the test product.

[0031] Preferably, the voltage-regulated constant-current DC charging unit adopts a voltage-doubling rectifier constant-current charging method to convert the 380V three-phase electricity of the power supply into a charging voltage of a predetermined value; the voltage-regulated constant-current DC charging unit controls the polarity through a thyristor and adopts a single-phase column electric voltage regulator to track the voltage regulation to achieve constant-current charging; a charging protection resistor is provided on the high-voltage side of the voltage-regulated constant-current DC charging unit, and a series protection resistor is provided on the low-voltage side.

[0032] Preferably, the energy storage capacitor unit is connected in parallel through multiple groups of capacitors, the maximum charging voltage is 60kV, and the maximum output energy is 864kJ; the impact energy output by the energy storage capacitor unit is generated according to the charging voltage, and the discharge time of the energy storage capacitor unit is in the ms level.

[0033] Preferably, the rectification and filtering unit comprises a thyristor power electronic element and an inductor element, and rectifying and filtering the impact energy released by the capacitor unit to be triggered into DC energy.

[0034] Preferably, the power electronic chopper unit is used to break the forward and reverse current of 10kA, and the breaking time is within 5ms; the power electronic chopper unit includes a main branch, a transfer branch and an absorption branch; the main branch is used to bear the overvoltage at both ends of the DC-DC converter when the normal working current and the fault current are broken, and to realize the bidirectional conduction of the DC circuit; the transfer branch is used to generate an oscillating current in the opposite direction to the main branch current, and superimpose the reverse oscillating current on the main branch to force the fault current on the main branch to pass through zero, and transfer the fault current from the main branch to the transfer branch; the absorption branch is used to absorb and discharge the energy accumulated during fault breaking.

[0035] Preferably, the system further comprises a grounding loop consisting of a discharge resistor and a grounding switch, wherein the discharge resistor is a high voltage resistor with a resistance value of 20 kΩ; and the grounding switch is used for emergency stop by leading out a control switch.

[0036] Preferably, it also includes: the system also includes an impact resistor divider connected in parallel to both ends of the test sample, the test sample is connected in series with the impact current loop and then connected in parallel to the power electronic chopper unit and the grounding wire; the impact resistor divider is a resistive voltage divider with a rated voltage of 30kV and an accuracy of 1%; the wave response time of the impact resistor divider is not more than 20ns, and the transformation ratio is 100V / V.

[0037] Preferably, it also includes a sample operating table, which is an aluminum alloy profile and has a test station, and the sample is set on the test station;

[0038] An epoxy protection plate is installed around the test station, and the test sample is clamped by a pneumatic mechanism so that the test sample is in close contact with the electrodes of the test station.

[0039] Preferably, the impulse current measuring coil is a Rogowski coil with a transformation ratio of 100A / V.

[0040] Preferably, the voltage-regulated constant-current DC charging unit is also connected to a second energy storage capacitor unit, a second rectifier and filter unit, and a second power electronic chopper unit;

[0041] The voltage-regulated constant-current DC charging unit transmits the charging voltage to the second energy storage capacitor unit;

[0042] The high-voltage end of the second energy storage capacitor unit outputs the impact energy released by the second energy storage capacitor unit to the second rectifier and filter unit;

[0043] The second rectifying and filtering unit rectifies the impact energy into direct current energy, and outputs the direct current energy to the second power electronic chopper unit.

[0044] According to another aspect of the present invention, the present invention provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, wherein the computer program is used to execute a long-duration impulse current test method based on power electronic chopping.

[0045] Based on another aspect of the present invention, the present invention provides an electronic device, the electronic device comprising: a processor and a memory; wherein,

[0046] The memory is a memory for storing instructions executable by the processor;

[0047] The processor is used for reading the executable instructions from the memory and executing the instructions to implement a long-duration impulse current test method based on power electronic chopping.

[0048] The technical solution of the present invention provides a long-duration impulse current test system and method based on power electronic chopping, wherein the system includes: a voltage-regulated constant-current DC charging unit, an energy storage capacitor unit, a rectifier filter unit, and a power electronic chopper unit connected in sequence; the power supply is directly connected to the voltage-regulated constant-current DC charging unit, and the voltage-regulated constant-current DC charging unit outputs a continuously adjusted charging voltage, and transmits the charging voltage to the energy storage capacitor unit; the low-voltage end of the energy storage capacitor unit is grounded through a grounding wire, and the high-voltage end of the energy storage capacitor unit outputs the impulse energy released by the energy storage capacitor unit to the rectifier filter unit; the rectifier filter unit rectifies the impulse energy into DC energy, and outputs the DC energy to the power electronic chopper unit; the power electronic chopper unit is used to control the breaking time to cut off the DC energy into a DC current of a preset wavelength and preset polarity, so that the output current waveform meets the test requirements. The technical solution of the present invention provides a long-duration impulse current test system and method based on power electronic chopper, which improves the test wave modulation efficiency and reduces safety risks. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] A more complete understanding of exemplary embodiments of the present invention may be obtained by referring to the following drawings:

[0050] Figure 1 A structural diagram of a long-duration impulse current test system based on power electronic chopping according to a preferred embodiment of the present invention;

[0051] Figure 2 A structural diagram of a long-duration impulse current test system based on power electronic chopping according to a preferred embodiment of the present invention; and

[0052] Figure 3 The present invention is a flow chart of a long-duration impulse current test method based on power electronic chopping according to a preferred embodiment of the present invention. DETAILED DESCRIPTION

[0053] Now, exemplary embodiments of the present invention are described with reference to the accompanying drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. These embodiments are provided to disclose the present invention in detail and completely and to fully convey the scope of the present invention to those skilled in the art. The terms used in the exemplary embodiments shown in the accompanying drawings are not intended to limit the present invention. In the accompanying drawings, the same units / elements are marked with the same reference numerals.

[0054] Unless otherwise specified, the terms (including technical terms) used herein have the commonly understood meanings to those skilled in the art. In addition, it is understood that the terms defined in commonly used dictionaries should be understood to have the same meanings as those in the context of the relevant fields, and should not be understood as idealized or overly formal meanings.

[0055] In order to improve the efficiency of test wave modulation and reduce safety risks, the present invention proposes a long-duration impulse current test system based on power electronic chopping technology. The long-duration impulse current test system based on power electronic chopping technology of the present invention adopts an integrated design of energy storage elements, rectifier filter units and power electronic switch units. The entire test system is integrated in a container, and can realize the controllable and adjustable output of the impulse current waveform in the wavelength range of 5ms to 100ms through a program. The present invention can better simulate the long-duration impulse current in the range of up to 100ms under special working conditions, solving the problem that the output waveform of the existing chain loop does not exceed 10ms; the present invention can control the on-off time of the power electronic switch unit through a program to achieve controllable adjustment of the output waveform, solving the problem of low test efficiency and high safety risks caused by the manual replacement of capacitor and inductor wiring in the existing test loop; the present invention adopts a rectifier filter unit to directly adjust the capacitor charging and discharging waveform into a DC waveform, reducing the use of inductors, and avoiding the problem of loose and broken inductor wiring caused by long-term testing.

[0056] The present invention provides a long-duration impulse current test system based on power electronic chopping technology, which adopts an integrated design of energy storage elements, rectifier filter units and power electronic switch units. The entire test system is integrated in a container, and can realize controllable and adjustable output of impulse current waveforms within a wavelength range of 5ms to 100ms through a program. The present invention can better simulate long-duration impulse currents within a range of up to 100ms under special working conditions, solving the problem that the output waveform of the existing chain loop does not exceed 10ms; the present invention can control the disconnection time of the power electronic switch unit through a program to achieve controllable adjustment of the output waveform, solving the problem of low test efficiency and high safety risks caused by the manual replacement of capacitor and inductor wiring in the existing test loop; the present invention adopts a rectifier filter unit to directly adjust the capacitor charging and discharging waveform into a DC waveform, reducing the use of inductors, and avoiding the problem of loose and broken inductor wiring caused by long-term testing.

[0057] like Figure 1 As shown, the present invention provides a long-duration impulse current test system based on power electronic chopper, the system includes: a voltage-regulated constant-current DC charging unit 102, an energy storage capacitor unit 103, a rectifier and filter unit 104, and a power electronic chopper unit 105 connected in sequence;

[0058] The present invention provides a long-duration impulse current test system based on power electronic chopping technology, comprising: a voltage-regulated constant-current DC charging unit 102, an energy storage capacitor unit 103, a rectifier and filter unit 104, a power electronic chopper unit 105, a discharge resistor 106, a grounding switch 107 and a test product operating table 109, wherein a measuring circuit of an impulse current measuring coil 110 and an impulse resistor voltage divider 108 can be added as required, and a reverse polarity circuit can be added as required for testing to output a long-duration impulse current with reversed positive and negative polarities.

[0059] The power source 101 is directly connected to the voltage-regulated constant-current DC charging unit 102, and the voltage-regulated constant-current DC charging unit 102 outputs a continuously adjusted charging voltage, and transmits the charging voltage to the energy storage capacitor unit 103;

[0060] Preferably, the voltage-regulated constant-current DC charging unit 102 adopts a voltage-doubling rectifier constant-current charging method, which converts the 380V three-phase electricity of the power supply into a charging voltage of a predetermined value; the voltage-regulated constant-current DC charging unit controls the polarity through a thyristor, and uses a single-phase column electric voltage regulator to track the voltage regulation to achieve constant-current charging; a charging protection resistor is provided on the high-voltage side of the voltage-regulated constant-current DC charging unit, and a series protection resistor is provided on the low-voltage side.

[0061] The low voltage end of the energy storage capacitor unit 103 is grounded through a grounding wire, and the high voltage end of the energy storage capacitor unit 103 outputs the impact energy released by the energy storage capacitor unit to the rectification and filtering unit 104;

[0062] Preferably, the energy storage capacitor unit 103 is connected in parallel by multiple groups of capacitors, with a maximum charging voltage of 60kV and a maximum output energy of 864kJ; the impact energy output by the energy storage capacitor unit is controlled by controlling the charging voltage, and the discharge time of the energy storage capacitor unit is in the ms level.

[0063] The rectifying and filtering unit 104 rectifies the impact energy into DC energy, and outputs the DC energy to the power electronic chopper unit 105;

[0064] The rectifier and filter unit 104 of the present invention changes the design method of the original chain square wave test circuit, and is composed of power electronic components such as thyristors and inductor components. It has a specially designed topological structure and can rectify the impact energy released by the capacitor unit into DC energy through rectification and filtering.

[0065] Preferably, the rectifying and filtering unit 104 comprises a thyristor power electronic element and an inductor element, and rectifying the impact energy released by the capacitor unit when triggered into direct current energy through rectification and filtering.

[0066] The power electronic chopper unit is used to cut the DC energy into a DC current of preset wavelength and preset polarity by controlling the breaking time, so that the output current waveform meets the test requirements.

[0067] The grounding loop composed of the discharge resistor 106 and the grounding switch 107 is connected in parallel to the power electronic chopper unit 105 and the grounding wire;

[0068] The test product is connected in series with the impulse current coil 110 and then connected in parallel with the power electronic chopper unit and the ground wire;

[0069] The impulse resistor voltage divider 108 is connected in parallel to both ends of the test product.

[0070] Preferably, the power electronic chopper unit 105 is used to interrupt the forward and reverse currents of 10kA, and the interruption time is within 5ms; the power electronic chopper unit includes a main branch, a transfer branch and an absorption branch; the main branch is used to bear the overvoltage at both ends of the DC-DC converter when the normal working current and the fault current are interrupted, and to realize the bidirectional conduction of the DC circuit; the transfer branch is used to generate an oscillating current in the opposite direction to the main branch current, and superimpose the reverse oscillating current on the main branch to force the fault current on the main branch to pass through zero, and transfer the fault current from the main branch to the transfer branch; the absorption branch is used to absorb and discharge the energy accumulated during fault interruption.

[0071] The power electronic chopper unit 105 of the present invention is a specially designed programmable DC-DC converter based on a power electronic switch, which can interrupt 10kA forward and reverse currents and is used to control the duration of the output current. The interruption time can be arbitrarily controlled within 5ms to 100ms.

[0072] Preferably, the system further comprises a grounding loop consisting of a discharge resistor and a grounding switch, wherein the discharge resistor is a high voltage resistor with a resistance value of 20 kΩ; the grounding switch is used for emergency stop by leading out a control switch.

[0073] Preferably, the system also includes an impact resistor divider connected in parallel to both ends of the test sample, and the test sample is connected in series with the impact current loop and then connected in parallel to the power electronic chopper unit and the grounding wire; the impact resistor divider is a resistive voltage divider with a rated voltage of 30kV and an accuracy of 1%; the wave response time of the impact resistor divider is no more than 20ns, and the transformation ratio is 100V / V.

[0074] Preferably, it also includes a sample operating table, which is an aluminum alloy profile and has a test station, and the sample is set on the test station;

[0075] An epoxy protection plate is installed around the test station, and the test sample is clamped by a pneumatic mechanism so that the test sample is in close contact with the electrodes of the test station.

[0076] Preferably, the impulse current measuring coil is a Rogowski coil with a transformation ratio of 100 A / V.

[0077] Preferably, the voltage-regulated constant-current DC charging unit may also be connected to the second energy storage capacitor unit, the second rectifying and filtering unit, and the second power electronic chopper unit;

[0078] The voltage-regulated constant-current DC charging unit transmits the charging voltage to the second energy storage capacitor unit;

[0079] The high-voltage end of the second energy storage capacitor unit outputs the impact energy released by the second energy storage capacitor unit to the second rectification and filtering unit;

[0080] The second rectifying and filtering unit rectifies the impact energy into direct current energy, and outputs the direct current energy to the second power electronic chopper unit.

[0081] The aforementioned installation of a group of energy storage capacitor units 201, rectification and filtering units 202 and power electronic chopper units 203 can simultaneously charge at the other polarity and output a reverse impulse current. The conduction time is controlled by the power electronic chopper unit 203 to coordinate the output of a long-duration impulse current with positive and negative polarity reversal.

[0082] The present invention provides a long-duration impulse current test system based on power electronic chopping technology, which includes: a voltage-regulated constant-current DC charging unit 102, an energy storage capacitor unit 103, a rectifier and filter unit 104, a power electronic chopper unit 105, a discharge resistor 106, a grounding switch 107 and a test product operating table 109, and a measurement circuit of an impulse current measuring coil 110 and an impulse resistor voltage divider 108 can be added as needed.

[0083] The voltage-regulated constant-current DC charging unit 102 of the present invention adopts a voltage-doubling rectifier constant-current charging method to convert 380V three-phase electricity into a charging voltage with a rated output of 60kV. The output voltage is continuously adjustable from zero to a set voltage, and the charging voltage of the energy storage capacitor unit is controlled by a measurement and control program.

[0084] The energy storage capacitor unit 103 of the present invention uses 10 groups of 60kV / 48μF capacitors in parallel, with a maximum charging voltage of 60kV and a maximum output energy of 864kJ. The impact energy output by the energy storage capacitor unit is generated according to the charging voltage, and the discharge time of the energy storage capacitor unit is in the ms level.

[0085] The rectifier and filter unit 104 of the present invention is composed of power electronic components such as thyristors and inductor components, and has a specially designed topological structure, and can rectify the impact energy released by the capacitor unit when triggered into DC energy through rectification and filtering.

[0086] The power electronic chopper unit 105 of the present invention is a programmable DC-DC converter based on a power electronic switch, which can interrupt the forward and reverse current of 10kA with an interruption time of less than 5ms. By controlling the interruption time of the DC-DC converter through a program, the output waveform wavelength can be controlled and adjusted within 5ms to 100ms.

[0087] The grounding circuit composed of the discharge resistor 106 and the grounding switch 107 of the present invention is used for emergency stop operation to discharge the energy stored in the test circuit, thereby ensuring the safety of the test personnel in replacing the test product and the grounding operation in case of emergencies.

[0088] The impulse resistor voltage divider 108 of the present invention is a resistor voltage divider with a rated voltage of 30 kV, an accuracy of 1%, a square wave response time of no more than 20 ns, and a transformation ratio of 100 V / V.

[0089] The impulse current measuring coil 110 of the present invention is a Rogowski coil, which has the advantages of non-contact, large measuring current, strong anti-interference ability, and not easy to be damaged, and the transformation ratio is 100A / V.

[0090] The sample operation table 109 of the present invention is made of aluminum alloy profiles and has a test station. The sample is mounted on the station and an epoxy protection plate is installed around the sample. The sample is clamped by a pneumatic mechanism to ensure close contact between the sample and the electrode.

[0091] The voltage-regulated constant-current DC charging unit 102 of the present invention is connected to a 380V three-phase power supply 101 at one end, and connected to an energy storage capacitor unit 103 at the other end; the low-voltage end of the energy storage capacitor unit 103 is grounded, and the high-voltage end is connected to a rectifier filter unit 104, and the energy output of the energy storage capacitor is controlled by controlling the charging voltage; the rectifier filter unit 104 is connected in series to the energy storage capacitor unit 103, and the impact energy released by the capacitor unit is rectified into DC energy by rectification and filtering; the power electronic chopper unit 105 is connected in series to the rectifier filter unit 104, and the DC-DC converter is controlled by a program to cut off the DC current according to the timing set by the program to discharge the residual energy; the grounding loop composed of a discharge resistor 106 and a grounding switch 107 is connected in parallel between the high-voltage DC circuit breaker unit 105 and the ground wire for emergency stop operation; the impact resistor voltage divider 108 is connected in parallel to the two ends of the test sample; the impact current coil 110 is connected in series to the low-voltage end of the test sample; the test sample is installed in a test sample operating table 109, and an epoxy protection plate is installed around it.

[0092] The voltage-regulated constant-current DC charging unit 102, the energy storage capacitor unit 103, the rectifier filter unit 104, the power electronic chopper unit 105, the discharge resistor 106 and the grounding switch 107 of the present invention are designed in a centralized manner, and are installed in a container. The test personnel only need to connect an external 380V three-phase power supply 101, a ground wire and a test product operating table 109 to carry out the test, and the installation is convenient and safe.

[0093] According to the needs, the present invention can also be equipped with a group of energy storage capacitor units 201, rectifier filter units 202 and power electronic chopper units 203, and charge at the other polarity at the same time, output reverse impact current, and control the conduction time through the power electronic chopper unit 203 to coordinate the output of positive and negative polarity reversal of long duration impact current. Figure 2 shown.

[0094] Figure 3 The present invention is a flow chart of a long-duration impulse current test method based on power electronic chopping according to a preferred embodiment of the present invention.

[0095] like Figure 3 As shown, the present invention provides a method for performing an impulse current test based on the system of claim 1, the method comprising:

[0096] Step 101: outputting a continuously adjusted charging voltage through a voltage-regulated constant-current DC charging unit, and transmitting the charging voltage to an energy storage capacitor unit;

[0097] Step 102: releasing the impact energy through the energy storage capacitor unit, and outputting the impact energy to the rectification and filtering unit;

[0098] Step 103: rectifying the impact energy into DC energy through a rectifying and filtering unit, and outputting the DC energy to a power electronic chopper unit;

[0099] Step 104: The DC energy is cut into a DC current of a preset wavelength by a power electronic chopper unit, and the DC current is applied to the test product.

[0100] Preferably, the voltage-regulated constant-current DC charging unit adopts a voltage-doubling rectifier constant-current charging method, which converts the 380V three-phase electricity of the power supply into a charging voltage of a predetermined value; the voltage-regulated constant-current DC charging unit controls the polarity through a thyristor, and uses a single-phase column electric voltage regulator to track the voltage regulation to achieve constant-current charging; a charging protection resistor is provided on the high-voltage side of the voltage-regulated constant-current DC charging unit, and a series protection resistor is provided on the low-voltage side.

[0101] Preferably, the energy storage capacitor unit is connected in parallel through multiple groups of capacitors, the maximum charging voltage is 60kV, and the maximum output energy is 864kJ; the impact energy output by the energy storage capacitor unit is generated according to the charging voltage, and the discharge time of the energy storage capacitor unit is in the ms level.

[0102] Preferably, the rectifying and filtering unit comprises a thyristor power electronic element and an inductor element, and rectifying and filtering the impact energy released by the capacitor unit to be triggered into direct current energy.

[0103] Preferably, the power electronic chopper unit is used to interrupt the forward and reverse currents of 10kA, and the interruption time is within 5ms; the power electronic chopper unit includes a main branch, a transfer branch and an absorption branch; the main branch is used to bear the overvoltage at both ends of the DC-DC converter when the normal working current and the fault current are interrupted, and to realize the bidirectional conduction of the DC circuit; the transfer branch is used to generate an oscillating current in the opposite direction to the main branch current, and superimpose the reverse oscillating current on the main branch to force the fault current on the main branch to pass through zero, and transfer the fault current from the main branch to the transfer branch; the absorption branch is used to absorb and discharge the energy accumulated during fault interruption.

[0104] Preferably, the system further comprises a grounding loop consisting of a discharge resistor and a grounding switch, wherein the discharge resistor is a high voltage resistor with a resistance value of 20 kΩ; the grounding switch is used for emergency stop by leading out a control switch.

[0105] Preferably, it also includes: the system also includes an impact resistor divider connected in parallel to both ends of the test sample, the test sample is connected in series with the impact current loop and then connected in parallel to the power electronic chopper unit and the grounding wire; the impact resistor divider is a resistive voltage divider with a rated voltage of 30kV and an accuracy of 1%; the wave response time of the impact resistor divider is not more than 20ns, and the transformation ratio is 100V / V.

[0106] Preferably, it also includes a sample operating table, which is an aluminum alloy profile and has a test station, and the sample is set on the test station;

[0107] An epoxy protection plate is installed around the test station, and the test sample is clamped by a pneumatic mechanism so that the test sample is in close contact with the electrodes of the test station.

[0108] Preferably, the impulse current measuring coil is a Rogowski coil with a transformation ratio of 100 A / V.

[0109] Preferably, the voltage-regulated constant-current DC charging unit is also connected to the second energy storage capacitor unit, the second rectifier and filter unit, and the second power electronic chopper unit;

[0110] The voltage-regulated constant-current DC charging unit transmits the charging voltage to the second energy storage capacitor unit;

[0111] The high-voltage end of the second energy storage capacitor unit outputs the impact energy released by the second energy storage capacitor unit to the second rectification and filtering unit;

[0112] The second rectifying and filtering unit rectifies the impact energy into direct current energy, and outputs the direct current energy to the second power electronic chopper unit.

[0113] A long-duration impulse current test method based on power electronic chopping in a preferred embodiment of the present invention corresponds to a long-duration impulse current test system based on power electronic chopping in another preferred embodiment of the present invention, which will not be described in detail here.

[0114] The present invention provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and the computer program is used to execute a long-duration impulse current test method based on power electronic chopping.

[0115] The present invention provides an electronic device, the electronic device comprising: a processor and a memory; wherein:

[0116] Memory, a memory for storing processor executable instructions;

[0117] The processor is used for reading executable instructions from the memory and executing the instructions to implement a long-duration impulse current test method based on power electronic chopping.

[0118] It will be appreciated by those skilled in the art that embodiments of the present invention may be provided as methods, systems, or computer program products. Therefore, the present invention may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program codes. The schemes in the embodiments of the present invention may be implemented in various computer languages, for example, object-oriented programming language Java and literal scripting language JavaScript, etc.

[0119] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0120] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0121] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0122] Although the preferred embodiments of the present invention have been described, those skilled in the art may make other changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention.

[0123] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

[0124] The invention has been described above with reference to a few embodiments. However, it is readily apparent to a person skilled in the art that other embodiments than the ones disclosed above are equally within the scope of the invention, as defined by the appended patent claims.

[0125] Generally, all terms used in the claims are to be interpreted according to their ordinary meaning in the technical field, unless explicitly defined otherwise herein. All references to "a / / the [means, component, etc.]" are to be openly interpreted as at least one instance of a means, component, etc., unless explicitly stated otherwise. The steps of any method disclosed herein do not necessarily have to be performed in the exact order disclosed, unless explicitly stated otherwise.

Claims

1. A long-duration impulse current test system based on power electronic chopper, the system comprising: a voltage-regulated constant-current DC charging unit, an energy storage capacitor unit, a rectifier and filter unit, and a power electronic chopper unit connected in sequence; The power supply is directly connected to the voltage-regulated constant-current DC charging unit, outputs a continuously adjusted charging voltage through the voltage-regulated constant-current DC charging unit, and transmits the charging voltage to the energy storage capacitor unit; The low-voltage end of the energy storage capacitor unit is grounded through a grounding wire, and the high-voltage end of the energy storage capacitor unit outputs the impact energy released by the energy storage capacitor unit to the rectification and filtering unit; The rectifying and filtering unit rectifies the impact energy into DC energy, and outputs the DC energy to the power electronic chopper unit; The power electronic chopper unit is used to cut the DC energy into a DC current of a preset wavelength and a preset polarity by controlling the breaking time, so that the output current waveform meets the test requirements.

2. According to the system of claim 1, the voltage-regulated constant-current DC charging unit adopts a voltage-doubling rectifier constant-current charging method to convert the 380V three-phase electricity of the power supply into a charging voltage of a predetermined value; the voltage-regulated constant-current DC charging unit controls the polarity through a thyristor and adopts a single-phase column electric voltage regulator to track and regulate the voltage to achieve constant-current charging; a charging protection resistor is provided on the high-voltage side of the voltage-regulated constant-current DC charging unit, and a series protection resistor is provided on the low-voltage side.

3. According to the system of claim 1, the energy storage capacitor unit is connected in parallel through multiple groups of capacitors, the maximum charging voltage is 60kV, and the maximum output energy is 864kJ; the impact energy output by the energy storage capacitor unit is generated according to the charging voltage, and the discharge time of the energy storage capacitor unit is in the ms level.

4. The system according to claim 1, wherein the rectifying and filtering unit comprises a thyristor power electronic element and an inductor element, and rectifying and filtering the impact energy released by the capacitor unit to be triggered into DC energy.

5. According to the system of claim 1, the power electronic chopper unit is used to break the forward and reverse current of 10kA, and the breaking time is within 5ms; the power electronic chopper unit includes a main branch, a transfer branch and an absorption branch; the main branch is used to bear the overvoltage at both ends of the DC-DC converter when the normal working current and the fault current are broken, and realize the bidirectional conduction of the DC circuit; the transfer branch is used to generate an oscillating current in the opposite direction to the main branch current, and superimpose the reverse oscillating current on the main branch to force the fault current on the main branch to pass through zero, and transfer the fault current from the main branch to the transfer branch; the absorption branch is used to absorb and discharge the energy accumulated during fault breaking.

6. The system according to claim 1, wherein the power electronic chopper unit is used to control the breaking time so that the output current waveform meets the test requirements, and the breaking time can be arbitrarily controlled within 5ms to 100ms.

7. The system according to claim 1, further comprising a grounding loop consisting of a discharge resistor and a grounding switch, wherein the discharge resistor is a high-voltage resistor with a resistance value of 20 kΩ; and the grounding switch is used for emergency stop by leading out a control switch.

8. The system of claim 1, further comprising: The system also includes an impact resistor voltage divider connected in parallel to both ends of the test object, and the test object is connected in series with the impact current loop and then connected in parallel to the power electronic chopper unit and the grounding wire; the impact resistor voltage divider is a resistive voltage divider with a rated voltage of 30kV and an accuracy of 1%; the wave response time of the impact resistor voltage divider is no more than 20ns, and the transformation ratio is 100V / V.

9. The system according to claim 8, further comprising a sample operation table, the sample operation table is an aluminum alloy profile, and has a test station, and the sample is set on the test station; An epoxy protection plate is installed around the test station, and the test sample is clamped by a pneumatic mechanism so that the test sample is in close contact with the electrodes of the test station.

10. The system according to claim 8, wherein the impulse current measuring coil is a Rogowski coil with a transformation ratio of 100 A / V.

11. The system according to claim 1, wherein the voltage-regulated constant-current DC charging unit is further used to be connected to a second energy storage capacitor unit, a second rectifier filter unit and a second power electronic chopper unit to achieve output of another polarity current; The voltage-regulated constant-current DC charging unit transmits the charging voltage to the second energy storage capacitor unit; The high-voltage end of the second energy storage capacitor unit outputs the impact energy released by the second energy storage capacitor unit to the second rectifier and filter unit; The second rectifying and filtering unit rectifies the impact energy into direct current energy, and outputs the direct current energy to the second power electronic chopper unit. By changing the charging polarity, an impact current of another polarity is output, and the output time of the second power electronic chopper unit is controlled by a computer program, and used in conjunction with the first power electronic chopper unit, an impact current with reversed polarity is output.

12. A method for performing an impulse current test based on the system of claim 1, the method comprising: Outputting a continuously adjusted charging voltage through the voltage-regulated constant-current DC charging unit, and transmitting the charging voltage to the energy storage capacitor unit; Releasing the impact energy through the energy storage capacitor unit and outputting the impact energy to the rectification and filtering unit; Rectifying the impact energy into DC energy through the rectifying and filtering unit, and outputting the DC energy to the power electronic chopper unit; The DC energy is cut into a DC current of a preset wavelength and a preset polarity by the power electronic chopper unit, and the DC current is applied to the test product.

13. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program for executing the method of claim 12 .

14. An electronic device, characterized in that: The electronic device comprises: a processor and a memory; wherein, The memory is a memory for storing instructions executable by the processor; The processor is configured to read the executable instructions from the memory and execute the instructions to implement the method of claim 12.

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