Pressure equalizing test device for high-pressure valve group

Abstract

The utility model discloses a pressure equalizing test device for a high-pressure valve group. The pressure equalizing test device comprises a low-pressure test unit and a high-pressure suspension high-pressure test unit, wherein the low-voltage test unit comprises a computer terminal and a controller connected with the computer terminal; the high-voltage test unit comprises a valve group, a probe and an oscilloscope which are connected in sequence; the computer terminal is connected with the oscilloscope, and the controller is connected with the valve group. According to the utility model, the high-voltage breakdown phenomenon can be avoided, so that the safety risk of voltage-sharing testing in a high-voltage environment is reduced, and the convenience and safety of testing are improved.

Description

Technical Field

[0001] The utility model relates to the technical field of power electronic converters, and more particularly to a high-pressure valve group pressure equalization testing device. Background Art

[0002] In direct current (DC) transmission systems, commutation technology is one of the key technologies for achieving efficient power transmission. With the advancement of DC transmission technology, performance requirements for high-voltage, high-power converter components are increasing. As a core component of DC transmission systems, the reliability and stability of converter valves are directly related to the operational safety and efficiency of the entire system.

[0003] In converter valve design, multiple switches are typically connected in series to divide the voltage to achieve the required voltage level. This design requires a high degree of uniformity in voltage distribution across each switch. Specifically, the voltage drop across each switch should be as consistent as possible to avoid damage to the switch or system failure caused by uneven voltage distribution.

[0004] However, existing high-pressure valve group equalization testing methods have many shortcomings. In traditional testing methods, the test equipment is exposed to high pressure, which poses the risk of high-voltage breakdown, potentially damaging test equipment such as oscilloscopes and even endangering the safety of testers. Utility Model Content

[0005] To overcome these shortcomings, this utility model provides a high-pressure valve group equalization test device. Its primary purpose is to provide a safe, fast, and economical solution for high-pressure valve group equalization testing. This device allows for rapid and accurate measurement of the voltages of individual switching transistors in a high-pressure valve group by suspending the high-voltage test unit, without the need for dedicated high-voltage probes.

[0006] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0007] A high-pressure valve group pressure equalization test device includes a low-pressure test unit and a high-pressure suspended high-pressure test unit, wherein:

[0008] The low voltage test unit includes a computer terminal and a controller connected thereto for transmitting control commands and data;

[0009] The high-voltage test unit includes a valve group, a probe, and an oscilloscope connected in sequence. The oscilloscope is directly connected to the valve group through the probe and is used to monitor the voltage of each switch tube in the valve group.

[0010] The computer terminal is connected to the oscilloscope, and the controller is connected to the valve group.

[0011] Furthermore, the computer terminal is wirelessly connected to the oscilloscope.

[0012] Furthermore, the high-voltage test unit includes a first wireless router, and the first wireless router is connected to the oscilloscope via a network cable and is suspended together in a high-voltage environment.

[0013] Furthermore, the low-voltage test unit includes a second wireless router, which is connected to the computer terminal and wirelessly communicates with the first wireless router. The computer is connected to the wireless router at the high-voltage position via wireless signals for remote control and data transmission.

[0014] Furthermore, the high-voltage test unit also includes an isolated power supply, which is connected to the probe, the oscilloscope and the first wireless router respectively, and is used to supply power to the oscilloscope, the first wireless router and the probe.

[0015] Furthermore, the controller is connected to the valve group via an optical fiber to achieve stable signal transmission and avoid high-voltage damage.

[0016] Furthermore, a high-voltage resistant platform is constructed using insulating beams, and the high-voltage test unit is placed on the high-voltage resistant platform to achieve high-voltage suspension.

[0017] The utility model sends out a double pulse signal through a background optical fiber, and utilizes an oscilloscope to remotely control and capture and store waveforms through a first wireless router and a second wireless router.

[0018] This new test device performs a pressure equalization test in the following steps:

[0019] Build a test circuit consisting of a low-voltage test unit and a high-voltage suspended high-voltage test unit;

[0020] Set the oscilloscope to trigger mode and determine the pulse width; then test the switch tubes on the valve group in turn, and save the recorded waveforms on the oscilloscope;

[0021] Finally, the voltage equalization test results are obtained based on the waveform.

[0022] As can be seen from the above technical solution, the present invention provides a high-pressure valve group equalization test device. By placing the high-voltage test unit on a high-voltage resistant platform, the device achieves high-voltage suspension and avoids high-voltage breakdown. At the same time, the high-voltage resistant platform constructed with insulating beams can effectively isolate the high-voltage test unit from the low-voltage test unit, reducing the safety risks of equalization testing in high-voltage environments.

[0023] Compared with the existing technology, the high-pressure valve group equalizing pressure test device of the utility model not only improves the convenience and safety of the test, but also provides an efficient and accurate testing method for the reliability assessment of the converter valve, which is of great significance for improving the overall performance and reliability of the DC transmission system.

[0024] In addition, this new model sends out dual pulse signals through the background optical fiber and uses a wireless router and oscilloscope background software to achieve remote control and data capture, greatly improving the efficiency and safety of the test. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are merely embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying any creative work.

[0026] Figure 1 The accompanying drawing is a structural diagram of the high-pressure valve group pressure equalization test device provided by the present invention;

[0027] Figure 2 The accompanying drawings are a schematic diagram of the valve group structure and a test principle diagram provided by the utility model;

[0028] Figure 3 The accompanying drawings are test waveform diagrams of the upper bridge arm IGCT Tu1 to Tu8 provided by the present invention;

[0029] Figure 4 The accompanying figure is a test waveform diagram of the upper bridge arm diodes Du1 to Du8 provided by the present invention;

[0030] Figure 5 The accompanying figure is a test waveform diagram of the lower bridge arm IGCT Td1 to Td8 provided by the present invention;

[0031] Figure 6 The attached figure is a test waveform diagram of the lower bridge arm diodes Dd1 to Dd8 provided by the present invention. DETAILED DESCRIPTION

[0032] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0033] The embodiment of the utility model discloses a high-pressure valve group pressure equalization test device, which mainly consists of two parts: a low-pressure test unit and a high-pressure suspended high-pressure test unit;

[0034] Setting the high-voltage test unit to a high-voltage suspended state can place it in a relatively independent potential state, preventing it from being directly connected to the ground or other objects at the same potential, thereby improving the electrical safety of the entire test environment and reducing the risk of high-voltage breakdown.

[0035] Among them, the low-voltage test unit includes a computer terminal and a controller connected thereto for transmitting control commands and data;

[0036] The high-voltage test unit includes a valve group, a probe, and an oscilloscope connected in sequence. The oscilloscope is directly connected to the valve group through the probe and is used to monitor the voltage of each switch tube in the valve group.

[0037] At the same time, the computer terminal is connected to the oscilloscope, and the controller is connected to the valve group, thereby forming a test loop.

[0038] In this embodiment, the controller and the valve group are connected via optical fiber to achieve stable signal transmission and avoid high-voltage damage; the computer terminal and the oscilloscope are wirelessly connected to achieve remote control.

[0039] Specifically, wireless connection is achieved through the following scheme:

[0040] The high-voltage test unit includes a first wireless router, and the first wireless router and the oscilloscope are connected via a network cable and suspended together in a high-voltage environment;

[0041] The low-voltage test unit includes a second wireless router, which is connected to a computer terminal and wirelessly communicates with the first wireless router. The computer connects to the first wireless router at the high-voltage position via wireless signals, thereby achieving remote control and data transmission.

[0042] To further optimize the above technical solution, the high-voltage test unit also includes an isolated power supply, which is connected to the probe, the oscilloscope and the first wireless router respectively, and is used to supply power to the oscilloscope, the first wireless router and the probe.

[0043] In order to further optimize the above technical solution, a high-voltage resistant platform is built using insulating beams, and the high-voltage test unit is placed on the high-voltage resistant platform to achieve high-voltage suspension.

[0044] This novel high-voltage platform, constructed using insulating beams, effectively isolates high-voltage and low-voltage test units, preventing high voltage from directly acting on low-voltage equipment (such as computer terminals and controllers), potentially damaging equipment or causing personal injury. Furthermore, since wireless routers, oscilloscopes, and other devices are placed on this platform, the voltage differential between them and the valve group under test remains relatively stable, reducing the possibility of high-voltage breakdown.

[0045] Furthermore, the requirements for the probe can be relaxed, that is, a differential probe with a lower voltage resistance can be used, or a high-voltage non-isolated probe can be used instead of a high-voltage probe for testing.

[0046] In an exemplary embodiment, Figure 1 As shown, the high-voltage test unit includes a valve block, probe, oscilloscope, isolated power supply, and the first wireless router. These components must be in a high-voltage suspension state during the test. The low-voltage test unit consists of a computer and controller to control the test process and process test data.

[0047] In this device, an isolated power supply powers the oscilloscope, the first wireless router, and the probe, ensuring they can function without interference in a high-voltage environment. The oscilloscope and the first wireless router are connected via a network cable and both are suspended in a high-voltage state to reduce the risk of high-voltage breakdown.

[0048] At the same time, the oscilloscope is directly connected to the valve group through the probe to monitor and record the voltage waveform of each switch tube in real time. Among them, the valve group is usually a structure with multiple high-power switch tubes connected in series. The test principle refers to Figure 2 Furthermore, the valve group and the controller are connected through optical fiber, which has good insulation performance and will not introduce additional high voltage risks due to signal transmission. The use of optical fiber not only ensures the stability of signal transmission, but also avoids potential damage to the controller due to high voltage.

[0049] The controller and computer are connected via a network cable to exchange data and transmit commands. The computer connects to a wireless router located at a high-voltage location via wireless signals, allowing for remote control and waveform capture and storage via an oscilloscope. This prevents testers from directly contacting potentially high-voltage equipment, ensuring the safety of the test process. Simultaneously enabling remote control and data transmission addresses the limitations of traditional testing methods, which hinder automation and remote control and limit test efficiency.

[0050] This new approach effectively reduces the safety risks of equalizing pressure tests under high-voltage conditions by combining physical isolation with remote control, thereby improving test efficiency and safety.

[0051] In another embodiment, when using the device to perform a pressure equalization test on a high-pressure valve group, the steps include:

[0052] 1. Build the test circuit according to the predetermined schematic diagram;

[0053] 2. Use the probe to monitor the valve group and set the oscilloscope to trigger mode;

[0054] 3. Calculate the pulse width according to the formula U=L*di / dt and set the current to the rated current;

[0055] 4. Start the power supply of the valve group and start the test through double pulse;

[0056] 5. The oscilloscope temporarily stores the action waveform and saves the waveform record;

[0057] 6. Test all the switch tubes on the valve group in turn, and save the waveforms and records.

[0058] As a preferred implementation method, mathematical tools such as MATLAB can be used to perform synthetic analysis on the data to save test time and obtain equalized voltage test results, so as to overcome the problems of large workload and long cycle caused by using special high-voltage probes to measure and compare the voltages between switching tubes one by one in the existing technology.

[0059] The solution of the utility model can significantly improve the safety, efficiency and accuracy of the pressure equalization test of the high-pressure valve group, and has important practical application value.

[0060] In a test instance,

[0061] The test conditions are 15kV / 1200A, the connected load reactance is 12mH, the two pulse widths are 500us and 460us respectively, the pulse interval is 100us, and the overlap time is 40us;

[0062] The dynamic and static voltage balancing conditions of the upper bridge arm IGCT T1~T8 and diodes Du1~Du8 are as follows: Figure 3 and Figure 4 shown.

[0063] For the upper bridge arm IGCT, its primary pulse shutdown current is 600A, and the maximum shutdown voltage peak is 2240V (IGCT7). In terms of static pressure resistance, the maximum pressure resistance is IGCT8 (1950V), and the minimum pressure resistance is IGCT5 (1700V). The secondary pulse shutdown current is 1200A, and the maximum shutdown voltage peak is 2440V (IGCT7). In terms of static pressure resistance, the maximum pressure resistance is IGCT8 (2000V), and the minimum pressure resistance is IGCT5 (1630V).

[0064] Furthermore, the test results show that the voltage-sharing consistency between IGCTs 7, 8, 6, and 4 is relatively good, as is the voltage-sharing consistency between IGCTs 3 and 2, and between IGCTs 1 and 5. However, there is no significant deviation in the overall voltage-sharing between the individual devices.

[0065] For the upper-arm diode, the pulsed turn-off current is 600A, the maximum turn-off voltage peak is 2450V (D1), and the static withstand voltage is the highest for D1 (2000V), while the lowest for D7 (1700V). Furthermore, the test results show that, with the exception of diode D1, the voltage-sharing conditions for the remaining diodes are nearly identical.

[0066] The dynamic and static voltage balancing conditions of the lower bridge arm IGCT Td1~Td8 and diodes Dd1~Dd8 are as follows: Figure 5 and Figure 6 As shown in the figure:

[0067] For the lower-arm IGCT, the primary pulse shutoff current is 600A, with a maximum shutoff voltage spike of 2500V (IGCT2). The maximum static withstand voltage is 2100V for IGCT2, and the minimum is 1600V for IGCT7. The secondary pulse shutoff current is 1200A, with a maximum shutoff voltage spike of 2750V (IGCT2). The maximum static withstand voltage is 2100V for IGCT2, and the minimum is 1550V for IGCT7. Furthermore, the test results show that the voltage balancing consistency between IGCTs 2, 5, 6, and 8 is good, and the voltage balancing consistency between IGCTs 3, 4, 1, and 7 is also good.

[0068] For the lower-arm diode, the pulsed turn-off current is 600A, the maximum turn-off voltage peak is 2460V (D2), and the maximum static withstand voltage is D2 (2000V), while the minimum withstand voltage is D8 (1700V). Furthermore, the test results show that the voltage balancing of the diodes is almost identical.

[0069] Double Pulse Conclusion:

[0070] 1) 7.7.1 The diode voltage balancing of the two test valve strings was almost identical, with a maximum uneven voltage difference of 300V, which was relatively small. The voltage balancing effect of the upper bridge arm IGCT valve string was relatively good. Under the 15kV / 1200A test conditions, the maximum shutdown voltage spike was 2440V (IGCT7). In terms of static pressure bearing, the maximum pressure bearing was IGCT8 (2000V), and the minimum pressure bearing was IGCT5 (1630V). The overall voltage balancing of each device did not show significant deviation.

[0071] 2) The voltage-sharing performance of the lower-arm IGCT string showed a four-way split. Under 15kV / 1200A test conditions, the maximum shutdown voltage spike was 2750V (IGCT2). Regarding static withstand voltage, IGCT2 had the highest withstand voltage (2100V), while IGCT7 had the lowest withstand voltage (1550V). The voltage-sharing consistency among IGCTs 2, 5, 6, and 8 was relatively good, while that among IGCTs 3, 4, 1, and 7 was also relatively good.

[0072] In general, during the full voltage test, the peak voltage of the device did not exceed 3500V, and the effective voltage value of the device did not exceed 2800V, so the test can be considered passed.

[0073] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. Reference can be made to the common and similar parts between the various embodiments. For the devices disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple, and the relevant parts can be referred to the method description.

[0074] The above description of the disclosed embodiments will enable one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be readily apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not limited to the embodiments shown herein but is intended to conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A high-pressure valve group pressure equalization test device, characterized in that: Including low-voltage test unit and suspended high-voltage test unit, The low-voltage test unit includes a computer terminal and a controller connected thereto; The high-voltage test unit includes a valve group, a probe, and an oscilloscope connected in sequence; The computer terminal is connected to the oscilloscope, and the controller is connected to the valve group.

2. A high-pressure valve group pressure equalization test device according to claim 1, characterized in that: The computer terminal is wirelessly connected to the oscilloscope.

3. A high-pressure valve group pressure equalization test device according to claim 2, characterized in that: The high-voltage test unit further includes a first wireless router, which is electrically connected to the oscilloscope.

4. A high-pressure valve group pressure equalization test device according to claim 3, characterized in that: The low-voltage test unit further includes a second wireless router, which is connected to the computer terminal and performs wireless communication with the first wireless router.

5. The high-pressure valve group pressure equalization test device according to claim 3, characterized in that: The high-voltage test unit further includes an isolated power supply, which is connected to the probe, the oscilloscope and the first wireless router respectively.

6. The high-pressure valve group pressure equalization test device according to claim 1, characterized in that: The controller is connected to the valve group via an optical fiber.

7. The high-pressure valve group pressure equalization test device according to claim 1, characterized in that: A high-voltage resistant platform is built using insulating beams, and the high-voltage test unit is placed on the high-voltage resistant platform to achieve high-voltage suspension.

Images