Testing tool and testing method for double-pulse test of full-control type device series valve
By using a dual-pulse test fixture for fully controllable series valves, safe, accurate, and efficient testing of high-pressure series valves was achieved, solving the testing challenges in engineering fields.
Patent Information
- Application Number
- CN202511624737.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-11-07
- Publication Date
- 2026-03-03
AI Technical Summary
When performing dual-pulse testing on high-voltage valve assemblies with multiple components connected in series at the engineering site, there are problems such as poor safety, low testing accuracy, cumbersome operation, and low efficiency.
A dual-pulse test fixture for a fully controllable series valve was designed, including a host computer main control unit, a control unit, a test unit, and a data acquisition unit. Through system integration and collaborative work, automated parameter calculation and safe and efficient testing are achieved.
It significantly improves the safety, accuracy, and efficiency of testing, avoids the safety risks of traditional manual operation, and provides a safe, accurate, and efficient testing platform.
Smart Images
Figure CN121595986A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of power electronics technology, specifically relating to a dual-pulse test fixture and test method for a fully controllable device series valve. Background Technology
[0002] Medium- and high-voltage power electronic converter valves are core devices for integrating new energy sources into the grid and are also crucial for improving the grid's transmission capacity, stability, and power quality. In medium- and high-voltage applications, power devices are required to have high withstand voltages, which cannot currently be met by individual devices. Therefore, by directly connecting fully controlled devices such as metal-oxide-semiconductor field-effect transistors (MOSFETs) or insulated-gate bipolar transistors (IGBTs) in series, the withstand voltage rating of the power electronic converter valve is increased to meet the voltage requirements of medium- and high-voltage applications.
[0003] In high-voltage, high-power applications (such as flexible DC transmission and large-capacity frequency converters), multiple fully controlled power devices (such as IGBTs and SiC MOSFETs) are often connected in series to form valve groups to meet system withstand voltage requirements. However, the dispersion of device parameters (such as differences in switching speed, junction capacitance, and threshold voltage) can lead to failure of series dynamic voltage equalization, thereby causing overvoltage damage to the devices. Double Pulse Test (DPT), as a core method for verifying the dynamic performance of devices, is irreplaceable in ensuring the reliable operation of series valves.
[0004] Currently, in the verification and testing of series valves with fully controllable devices in engineering fields, due to the large number of series valves, the complicated wiring of the double pulse test, the complex engineering field environment, the high voltage level, and the high required isolation voltage level, conventional testing instruments cannot meet the experimental requirements of series valves in engineering fields.
[0005] Therefore, there is an urgent need to propose a dual-pulse test fixture for fully controllable series valves, which can efficiently and conveniently realize the dynamic parameter measurement and accurate verification of the switching characteristics of fully controllable series valves. Summary of the Invention
[0006] The purpose of this invention is to solve the problems of poor safety, low testing accuracy, cumbersome operation, and low efficiency when performing dual-pulse testing on high-voltage valve groups with multiple devices connected in series in engineering sites.
[0007] The objective of this invention is achieved through the following technical solution: A dual-pulse test fixture for a fully controllable series valve includes: The host computer main control unit is used to send control commands, receive waveform data, and perform automated parameter calculations. The control unit, connected to the host computer main control unit, includes a high-voltage power supply, a support capacitor, and a bridge arm switching switch, used to provide adjustable high voltage and realize rapid reconfiguration of the test circuit; The test unit, which is electrically connected to the control unit and the device under test, includes a busbar box and a load inductor. The busbar box is used to interconnect the support capacitor, the load inductor, the bridge arm switching switch and the device under test to form a main energy transmission circuit. The acquisition unit, connected to the host computer main control unit and the test unit, includes an oscilloscope, a voltage probe and a current probe, and is used to capture the electrical parameter waveforms of the device under test in real time and upload them to the host computer main control unit.
[0008] The triple insulation design of the supporting capacitor, load inductor, and busbar system matches the insulation requirements of 4500V testing. The system-level insulation protection replaces the single-component design, improving high-voltage safety.
[0009] Furthermore, the output voltage of the high-voltage power supply is continuously adjustable within the range of 100V to 4500V, and it is directly coupled with the supporting capacitor to form an integrated high-voltage power supply unit. The test fixture adopts an integrated high-voltage power supply unit design, using a direct coupling design between a 4500V high-voltage power supply and a 500μF supporting capacitor, supporting plug-in / screw-type interfaces to expand the capacitor capacity, effectively solving the problem of voltage drop suppression in 1000A-level high-current testing.
[0010] Furthermore, the bridge arm switching switch is a mechanical three-position switch with three physical switching positions: upper bridge arm, lower bridge arm, and neutral, and integrates an interlocking protection mechanism to prevent high-voltage operation.
[0011] Furthermore, the busbar box employs a laminated busbar internally; the laminated busbar and the outgoing line of the load inductor have a predetermined length reserved and are connected by through-hole bolts to form a low stray inductance loop. The test fixture completes the low-inductance busbar topology design, with the laminated busbar and inductor outgoing line having a 500mm length reserved and connected by through-hole bolts to form a low stray inductance loop, optimizing parasitic parameters under high-voltage switch transients and improving test accuracy.
[0012] Furthermore, the load inductor is a pluggable and replaceable modular inductor, offering at least one inductance value among 50μH, 100μH, 200μH, and 500μH, with a pulse insulation strength of not less than 6000V / 1ms. It is suitable for di / dt testing requirements of 10-50kA / μs, balancing high insulation with convenience.
[0013] Furthermore, the voltage probe is a high-voltage differential voltage probe, and the current probe is a Rogowski coil current probe. The high-voltage differential voltage probe itself possesses a high common-mode rejection ratio and high isolation voltage, allowing direct measurement of device voltages floating at high potentials without grounding, ensuring measurement safety and accuracy. The Rogowski coil current probe is a non-contact measurement method that measures current through the principle of magnetic induction, achieving natural electrical isolation from the main circuit and fundamentally avoiding the risk of introducing high potentials into the oscilloscope and the human body.
[0014] Furthermore, the acquisition unit includes at least four high-voltage differential voltage probes and at least two Rogowski coil current probes. The four high-voltage differential probes and two Rogowski coils are hard synchronized with the oscilloscope to achieve nanosecond-level anti-interference acquisition of 5000V / 3000A signals.
[0015] Furthermore, the busbar of the busbar box has multiple pre-reserved voltage equalization test interfaces for connecting multiple devices under test in series, and providing an independent voltage detection point for each device. Employing the series device voltage equalization test interface, the busbar's pre-reserved bolt interface supports multiple tubes in series, with independent voltage detection for each tube (compatible with "two-series mode"), directly adapting to the testing requirements of series valve applications such as flexible DC transmission.
[0016] This invention also provides a double-pulse test method for a fully controllable series valve, using the aforementioned double-pulse test fixture, and the method includes the following steps: Test parameters are set via the host computer main control unit; The control unit controls the high-voltage power supply to charge the support capacitor, so that the bus voltage reaches the preset test voltage. A trigger command is sent using an oscilloscope, and the output of the high-voltage power supply is controlled to apply a test signal to the device under test. The electrical parameter waveforms of the device under test are captured in real time under test signals using voltage and current probes, and the waveform data is uploaded to the host computer main control unit. The host computer main control unit receives the waveform data and calculates the dynamic parameters of the switch.
[0017] Furthermore, the host computer control unit controls the boost / buck operation of the high-voltage power supply via the Modbus protocol and sends commands to the oscilloscope to automatically complete power supply voltage regulation, data acquisition, and dynamic parameter calculation. The host computer control unit synchronously controls the high-voltage power supply (100-4500V±1%), oscilloscope triggering, and parameter calculation via the Modbus protocol, automatically completing power supply voltage regulation, data acquisition, and dynamic parameter calculation (such as T). r , t f e on e off e rec Irm Q tail V CC1out dV CEon / d t dI CEon / d t ) calculation to achieve a closed-loop control method for the entire process.
[0018] Furthermore, the host computer main control unit controls the charging and discharging sequence of the high-voltage power supply to automate the rapid charging and discharging of the support capacitor and the dual-pulse test process. This achieves rapid charging and discharging of the bus capacitor and triggering of the dual-pulse signal, shortening the test cycle by more than 50% and avoiding the safety risks of traditional manual operation.
[0019] Compared with the prior art, the beneficial effects of the present invention are as follows: The fully controllable dual-pulse test fixture for series valves proposed in this invention achieves significant benefits through the systematic integration and collaborative operation of the host computer main control unit, control unit, test unit, and data acquisition unit. The host computer main control unit automates and intelligently integrates the test process, greatly improving efficiency and reducing human error. The high-voltage power supply and supporting capacitor coupling in the control unit provide a stable and adjustable high-voltage power supply, while the bridge arm switching switch ensures rapid and safe reconfiguration of the test circuit. The test unit, with the busbar box as its core, constructs an integrated, low-sensitivity energy transmission main circuit, ensuring the reliability and accuracy of the test, while the modular load inductor provides flexible test conditions. The data acquisition unit, through the cooperation of an oscilloscope and voltage and current probes, achieves real-time capture and data upload of key electrical parameters of the device. Overall, this fixture effectively solves the core problems of poor safety, cumbersome operation, insufficient accuracy, and low efficiency in traditional field dual-pulse testing of high-voltage series valves, providing a safe, accurate, and efficient test platform for engineering applications. Attached Figure Description
[0020] Figure 1 This is a structural block diagram of the test fixture system according to an embodiment of the present invention, wherein S1 and S2 are series valves of fully controllable devices; Figure 2 This is a schematic diagram of the topology of the dual-pulse test circuit of the present invention; Figure 3 This is a schematic diagram of the valve series wiring of the test fixture of the present invention; Among them, V DC C represents a DC voltage source, C represents a capacitor, and L represents an inductor. Detailed Implementation
[0021] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other instances that are improved or modified by those skilled in the art are within the scope of protection of the present invention. It should be understood that the embodiments of the present invention are only used to illustrate the technical effects of the present invention, and are not intended to limit the scope of protection of the present invention. Unless otherwise specified, the methods used in the embodiments are conventional methods.
[0022] Example 1 This embodiment proposes a dual-pulse test fixture for a fully controllable device series valve. The fixture features ultra-high testing capability of 4500V / 1000A, flexible configuration of modular inductors / capacitors, flexible switching of test modes, and automated analysis of dynamic parameters. It can efficiently and conveniently realize the dynamic parameter measurement and accurate verification of the switching characteristics of a fully controllable device series valve.
[0023] like Figure 1 As shown, the dual-pulse test fixture for the fully controllable series valve in this embodiment includes: The host computer main control unit is used to send control commands, receive waveform data, and perform automated parameter calculations. The control unit, connected to the host computer main control unit, includes a high-voltage power supply, a support capacitor, and a bridge arm switching switch, used to provide adjustable high voltage and realize rapid reconfiguration of the test circuit; The test unit, which is electrically connected to the control unit and the device under test, includes a busbar box and a load inductor. The busbar box is used to interconnect the support capacitor, the load inductor, the bridge arm switching switch and the device under test to form a main energy transmission circuit. The acquisition unit, connected to the host computer main control unit and the test unit, includes an oscilloscope, a voltage probe and a current probe, and is used to capture the electrical parameter waveforms of the device under test in real time and upload them to the host computer main control unit.
[0024] The host computer control unit includes, but is not limited to, a personal computer. The host computer controls the step-up and step-down operations of the high-voltage power supply via the Modbus protocol (USB to RS485 interface) and sends trigger commands and parameter configuration commands to the oscilloscope via a network cable. The dedicated control software running on the host computer receives waveform data uploaded from the oscilloscope, performs automated parameter calculations, including turn-on / turn-off delay time, rise / fall time, switching energy, reverse recovery characteristics, di / dt, dv / dt, etc., and provides intuitive feedback of the results.
[0025] Furthermore, the host computer control unit automatically executes the rapid charging and discharging of the support capacitor and the dual-pulse test process by precisely controlling the timing of the high-voltage power supply and the charging and discharging relays. This process enables rapid charging and discharging of the bus capacitor and precise triggering of the dual-pulse signal, shortening the test cycle by more than 50% and completely avoiding the safety risks associated with traditional manual operation.
[0026] The control unit includes a DC power supply module with a continuously adjustable output voltage from 100V to 4500V and a constant current output of 1A. Its output voltage accuracy reaches ±1% of the set value ±10V, and voltage stability is achieved through a closed-loop feedback circuit. This power supply, coupled with a 500μF supporting capacitor, forms an energy storage and discharge unit, ensuring that the bus voltage drop is controlled within 600V / 500μs during a 1000A double-pulse test. The supporting capacitor is connected in parallel between the positive and negative busbars of the busbar box and is equipped with a plug-in / bolt interface for capacity expansion. The bridge arm switching switch adopts a mechanical three-position design (upper bridge arm, lower bridge arm, neutral), with visual and tactile feedback switching via a handle. Its integrated interlocking protection mechanism mandates operation only after the busbar is de-energized, fundamentally eliminating the risk of live switching.
[0027] In the test unit, the busbar box serves as the core electrical hub. Its internal laminated busbars employ an alternating structure of positive and negative conductive layers and insulating layers, reliably interconnecting all power components (support capacitors, load inductors, bridge arm switching switches, and devices under test) to form the main circuit. To further optimize performance, a specific length of 500mm is reserved between the laminated busbars and the load inductor outputs, connected via through-hole bolts to form a low stray inductance circuit (typically in the tens of nH range), effectively suppressing parasitic oscillations during high-voltage switching transients. The load inductors offer pluggable modules with four inductance values: 50μH, 100μH, 200μH, and 500μH, with a pulse insulation strength as high as 6000V / 1ms, capable of withstanding current changes of 10-50kA / μs. In addition, the busbar has multiple voltage equalization test interfaces (compatible with "two-string mode"), which can be directly connected to each device in series to realize independent detection of the voltage of each tube, perfectly adapting to the testing requirements of voltage equalization characteristics of series valves in applications such as flexible DC transmission.
[0028] In the acquisition unit, the voltage probe is a high-voltage differential voltage probe, and the current probe is a Rogowski coil current probe. The high-voltage differential voltage probe itself has a high common-mode rejection ratio and high isolation voltage, allowing direct measurement of device voltages floating at high potentials without grounding, ensuring measurement safety and accuracy. The Rogowski coil current probe is a non-contact measurement method that measures current through the principle of magnetic induction, achieving natural electrical isolation from the main circuit and fundamentally avoiding the risk of introducing high potentials into the oscilloscope and the human body.
[0029] In this embodiment, the acquisition unit includes four high-voltage differential voltage probes and two Rogowski coil current probes, which are hard-synchronized with the oscilloscope. The voltage probes are directly connected to the collector-emitter terminals of the device under test (DUT) to measure the Vce waveform; the current probes surround the busbar to measure the Ic waveform. This configuration enables nanosecond-level, interference-resistant acquisition of 5000V / 3000A level signals. The oscilloscope is connected to the router via a network cable to transmit the acquired raw waveform data to the host computer in real time for analysis.
[0030] Example 2 This embodiment provides a dual-pulse test method for a fully controllable series valve, using the aforementioned dual-pulse test fixture. The method includes the following steps: Test parameters are set via the host computer main control unit; The control unit controls the high-voltage power supply to charge the support capacitor, so that the bus voltage reaches the preset test voltage. A trigger command is sent using an oscilloscope, and the output of the high-voltage power supply is controlled to apply a test signal to the device under test. The electrical parameter waveforms of the device under test are captured in real time under test signals using voltage and current probes, and the waveform data is uploaded to the host computer main control unit. The host computer main control unit receives the waveform data and calculates the dynamic parameters of the switch.
[0031] The host computer control unit controls the voltage boosting and bucking operations of the high-voltage power supply via the Modbus protocol and sends commands to the oscilloscope to automatically complete power supply voltage regulation, data acquisition, and dynamic parameter calculation. The host computer control unit synchronously controls the high-voltage power supply (100-4500V±1%), oscilloscope triggering, and parameter calculation via the Modbus protocol, automatically completing power supply voltage regulation, data acquisition, and dynamic parameter calculation (such as rise time T). r descent time t f Activate energy e on Turn off energy e off Reverse recovery energy e rec Reverse recovery peak current I rm Tail charge Q tail The voltage V tested during the first shutdown and the second startup. CC1out The collector-emitter voltage change rate dV during turn-on CEon / d t The rate of change of collector current dI during turn-on CEon / d t ) calculation to achieve a closed-loop control method for the entire process.
[0032] The host computer control unit controls the charging and discharging sequence of the high-voltage power supply to automate the rapid charging and discharging of the support capacitor and the dual-pulse test process. This enables rapid charging and discharging of the bus capacitor and triggering of the dual-pulse signal, shortening the test cycle by more than 50% and avoiding the safety risks of traditional manual operation.
[0033] During testing, the operator sets test parameters (such as voltage, inductance value, and bridge arm selection) on the host computer software interface. The software automatically controls the timing of the charging and discharging relays to complete the rapid charging and discharging of the supporting capacitor and trigger a dual-pulse signal. The acquisition unit synchronously captures the series valves S1 and S2 under test (e.g., Figure 2 , Figure 3 The software automatically calculates and displays all dynamic parameters and generates a test report after the voltage and current waveforms (as shown) are uploaded.
[0034] The tooling described in this invention, through the coordinated operation of the aforementioned units, successfully achieves safe, accurate, efficient, and convenient dual-pulse testing of high-pressure series valves, providing an effective technical means to solve the challenges of on-site engineering verification.
[0035] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.
Claims
1. A dual-pulse test fixture for a fully controllable series valve, characterized in that, include: The host computer main control unit is used to send control commands, receive waveform data, and perform automated parameter calculations. The control unit, connected to the host computer main control unit, includes a high-voltage power supply, a support capacitor, and a bridge arm switching switch, used to provide adjustable high voltage and realize rapid reconfiguration of the test circuit; The test unit, which is electrically connected to the control unit and the device under test, includes a busbar box and a load inductor. The busbar box is used to interconnect the support capacitor, the load inductor, the bridge arm switching switch and the device under test to form a main energy transmission circuit. The acquisition unit, connected to the host computer main control unit and the test unit, includes an oscilloscope, a voltage probe and a current probe, and is used to capture the electrical parameter waveforms of the device under test in real time and upload them to the host computer main control unit.
2. The dual-pulse test fixture according to claim 1, characterized in that, The output voltage of the high-voltage power supply is continuously adjustable within the range of 100V to 4500V, and it is directly coupled with the supporting capacitor to form an integrated high-voltage power supply unit.
3. The dual-pulse test fixture according to claim 1, characterized in that, The bridge arm switching switch is a mechanical three-position switch with three physical switching positions: upper bridge arm, lower bridge arm, and neutral. It also integrates an interlocking protection mechanism to prevent high-voltage operation.
4. The dual-pulse test fixture according to claim 1, characterized in that, The busbar box uses a laminated busbar inside; the laminated busbar and the output line of the load inductor are reserved with a predetermined length and are connected by through-hole bolts to form a loop with low stray inductance.
5. The dual-pulse test fixture according to claim 1, characterized in that, The load inductor is a pluggable and replaceable modular inductor, offering at least one inductance value among 50μH, 100μH, 200μH, and 500μH, and a pulse insulation strength of not less than 6000V / 1ms.
6. The dual-pulse test fixture according to claim 1, characterized in that, The voltage probe is a high-voltage differential voltage probe, and the current probe is a Rogowski coil current probe.
7. The dual-pulse test fixture according to claim 6, characterized in that, The acquisition unit includes at least four high-voltage differential voltage probes and at least two Rogowski coil current probes.
8. The dual-pulse test fixture according to claim 1, characterized in that, The busbar of the busbar box has multiple voltage equalization test interfaces reserved for connecting multiple devices under test in series, and providing an independent voltage detection point for each device.
9. A double-pulse test method for a fully controllable series valve, characterized in that, The method, employing the dual-pulse test fixture as described in any one of claims 1 to 8, comprises the following steps: Test parameters are set via the host computer main control unit; The control unit controls the high-voltage power supply to charge the support capacitor, so that the bus voltage reaches the preset test voltage. A trigger command is sent using an oscilloscope, and the output of the high-voltage power supply is controlled to apply a test signal to the device under test. The electrical parameter waveforms of the device under test are captured in real time under test signals using voltage and current probes, and the waveform data is uploaded to the host computer main control unit. The host computer main control unit receives the waveform data and calculates the dynamic parameters of the switch.
10. The test method according to claim 9, characterized in that, The host computer main control unit controls the step-up and step-down operation of the high-voltage power supply through the Modbus protocol and sends instructions to the oscilloscope to automatically complete the power supply voltage regulation, data acquisition and dynamic parameter calculation of the switch.
11. The test method according to claim 9, characterized in that, The host computer main control unit controls the charging and discharging sequence of the high-voltage power supply to realize the rapid charging and discharging of the support capacitor and the automated execution of the double-pulse test process.