Modularized commutated converter operation test system

Abstract

The invention relates to a modular commutation type converter operation test system, which comprises an energy complementing device, a soft start circuit, a load reactor, a sampling device and a centralized control device, and is characterized in that the energy complementing device comprises a plurality of direct current output ends, and each direct current output end is correspondingly connected with a test object switch capacitor module, so that energy complementing is carried out on each test object switch capacitor module independently. Under the control of the centralized control device, the energy complementing device is combined with the soft start circuit, so that the test object switch capacitor module and the test object H-bridge valve string are subjected to soft start charging operation, various different working conditions of the modular commutation type converter can be simulated, and the operation test of the modular commutation type converter can be realized according to set test parameters and operation test parameters. Through the scheme, the twin-dragging experiment of the test object switch capacitor module and the test object H-bridge valve string in the modular reversing converter can be realized, so that the blank of the MCC operation test platform is filled, and the product design capability and quality of the MCC are improved.

Description

Technical Field

[0001] The present application relates to the technical field of direct current transmission, and in particular to a modular commutation converter operation test system. Background Art

[0002] Deserts and Gobi regions are rich in wind and solar energy resources, which are conducive to large-scale centralized development, but there are many problems such as high power source uncertainty, high thermal power construction costs, low proportion of synchronous units, and weak local power grids. The current AC collection method faces challenges such as voltage instability, transient overvoltage, and broadband oscillation. It is expensive to configure a large number of synchronous support equipment such as thermal power units, phase regulators, and grid energy storage, and it cannot eliminate the synchronization stability problems caused by the first principle of AC collection.

[0003] Photovoltaic medium-voltage DC power generation has no frequency and phase synchronization problems, and can fundamentally solve the problem of AC power angle stability. In addition, through the full DC power transmission mode of DC collection and DC transmission, the amount of cables and power conversion links can be reduced. After mass production, the transmission efficiency and equipment manufacturing costs will be greatly reduced, which is an effective solution for the power transmission of large-scale new energy bases in the future.

[0004] The Modular Commutated Converter (MCC) is a new type of large and medium-sized DC / AC converter for photovoltaic medium-voltage DC collection, which can provide technical support for photovoltaic medium-voltage DC power generation.

[0005] However, in the related technologies, MCC lacks a matching operating test platform and many design indicators cannot be verified, which greatly limits MCC's product design capabilities and quality. Summary of the invention

[0006] Based on this, it is necessary to provide a modular commutation converter operation test system to address the above problems and verify the product performance of MCC, thereby improving the product design capability and quality of MCC.

[0007] The present application provides a modular commutation converter operation test system, comprising: an energy replenishment device, a soft start circuit, a load reactance, a sampling device and a centralized control device, wherein the energy replenishment device comprises a plurality of DC output terminals, each of which is connected to a test switch capacitor module, and the plurality of test switch capacitor modules are cascaded, and the energy replenishment device is used to provide DC power to each of the test switch capacitor modules; the first test switch capacitor module in the cascaded plurality of test switch capacitor modules is connected to a test H-bridge valve string through the soft start circuit, and the last test switch capacitor module is connected to the test H-bridge valve string; the load reactance is connected to the test H-bridge valve string; the sampling device is used to collect operation test parameters of the energy replenishment device, the test switch capacitor module and the test H-bridge valve string; the centralized control device is connected to the energy replenishment device, the soft start circuit, the sampling device, the test switch capacitor module and the test H-bridge valve string, and the centralized control device is used to control the soft start charging operation of the test switch capacitor module and the test H-bridge valve string, and to implement the operation test according to the set test parameters and the operation test parameters.

[0008] In one embodiment, the energy compensation device includes a multi-split winding transformer and a rectifier circuit, the rectifier circuit is connected to the centralized control device, the primary winding of the multi-split winding transformer is used to connect to an AC power supply, one secondary winding of the multi-split winding transformer is correspondingly connected to one of the rectifier circuits, and one of the rectifier circuits is correspondingly connected to one of the sample switching capacitor modules.

[0009] In one of the embodiments, the energy replenishment device further includes an AC source voltage regulator, the primary winding of the multi-split winding transformer is connected to the AC power source via the AC source voltage regulator, and the AC source voltage regulator is connected to the centralized control device.

[0010] In one of the embodiments, the energy replenishment device further includes a voltage-stabilizing capacitor and a discharge resistor connected in parallel, and the rectifier circuit is connected to the sample switch capacitor module via the voltage-stabilizing capacitor and the discharge resistor.

[0011] In one of the embodiments, the system further includes a host computer, and the centralized control device is communicatively connected to the host computer.

[0012] In one of the embodiments, the system further includes a wave recording device, and the centralized control device is connected to the wave recording device.

[0013] In one of the embodiments, the system further includes a water cooling device, the centralized control device is connected to the water cooling device, and the water cooling device is used to dissipate heat for the test switch capacitor module and the test H-bridge valve string.

[0014] In one embodiment, the soft start circuit includes a soft start resistor and a soft start switch connected in parallel, the soft start switch is connected to the centralized control device, and the centralized control device is also used to control the energy replenishment device to charge the test switch capacitor module, and when the charging of the test switch capacitor module is completed, control the soft start switch to turn off so as to charge the test H-bridge valve string through the soft start resistor; when the test H-bridge valve string is charged to a set voltage value, control the soft start switch to turn on to bypass the soft start resistor.

[0015] In one of the embodiments, charging the test H-bridge valve string through the soft-start resistor includes: after each H-bridge sub-unit of the test H-bridge valve string is powered, patrolling the H-bridge sub-units until the voltage of each H-bridge sub-unit reaches a set voltage value.

[0016] In one embodiment, the operation test items include: module communication test, minimum DC voltage test, overcurrent shutdown test, maximum current continuous operation capability test, maximum short-time overcurrent capability test, maximum voltage continuous operation capability test, fault bypass test, current flow test, normal temperature double pulse test, short circuit test, static withstand voltage test and at least one of the loss measurement test.

[0017] The above-mentioned modular commutation converter operation test system includes an energy replenishment device, a soft start circuit, a load inductor, a sampling device and a centralized control device. The energy replenishment device includes multiple DC output terminals, and each DC output terminal is connected to a test switch capacitor module, so that each test switch capacitor module is individually energized. Under the control of the centralized control device, the energy replenishment device is combined with the soft start circuit to enable the test switch capacitor module and the test H-bridge valve string to soft start and charge, thereby simulating a variety of different working conditions of the modular commutation converter. In this way, the operation test of the modular commutation converter can be realized according to the set test parameters and operation test parameters. Through this solution, the drag test of the test switch capacitor module and the test H-bridge valve string in the modular commutation converter can be realized, thereby filling the gap in the MCC operation test platform, thereby improving the product design capability and quality of the MCC. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the conventional technology, the drawings required for use in the embodiments or the conventional technology descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0019] Figure 1 This is a schematic diagram of the structure of a modular commutation converter in one embodiment of the present application;

[0020] Figure 2 This is a schematic diagram of the structure of a modular commutation converter operation test system in one embodiment of the present application;

[0021] Figure 3 This is a schematic diagram of the structure of a modular commutation converter operation test system in another embodiment of the present application;

[0022] Figure 4 This is a structural schematic diagram of a modular commutation converter operation test system in another embodiment of the present application;

[0023] Figure 5 This is a structural schematic diagram of a modular commutation converter operation test system in yet another embodiment of the present application;

[0024] Figure 6 This is a schematic diagram of the structure of a modular commutation converter operation test system in another embodiment of the present application;

[0025] Figure 7 This is a structural schematic diagram of a modular commutation converter operation test system in another embodiment of the present application;

[0026] Figure 8 This is a schematic diagram of the structure of a modular commutation converter operation test system in yet another embodiment of the present application. DETAILED DESCRIPTION

[0027] In order to facilitate the understanding of the present application, the present application will be described more fully below with reference to the relevant drawings. The preferred embodiments of the present application are provided in the drawings. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure of the present application more thorough and comprehensive.

[0028] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used herein in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application.

[0029] It is understood that the terms "first", "second", etc. used in this application may be used herein to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish a first element from another element. For example, without departing from the scope of this application, a first resistor may be referred to as a second resistor, and similarly, a second resistor may be referred to as a first resistor. Both the first resistor and the second resistor are resistors, but they are not the same resistor.

[0030] It can be understood that the “connection” in the following embodiments should be understood as “electrical connection”, “communication connection”, etc. if the connected circuits, modules, units, etc. have electrical signals or data transmission between each other.

[0031] It can be understood that “at least one” means one or more, “plurality” means two or more, and “at least part of an element” means part or all of an element.

[0032] When used herein, the singular forms "a", "an", and "said / the" may also include plural forms, unless the context clearly indicates otherwise. It should also be understood that the terms "include / comprise" or "have" and the like specify the presence of stated features, wholes, steps, operations, components, parts, or combinations thereof, but do not exclude the possibility of the presence or addition of one or more other features, wholes, steps, operations, components, parts, or combinations thereof. At the same time, the term "and / or" used in this specification includes any and all combinations of the relevant listed items.

[0033] The modular commutation converter operation test system provided in the embodiment of the present application is applied to the modular commutation converter. Figure 1 The modular commutation converter mainly includes three single-phase valves (see Figure 10), a converter transformer (see Figure T1) and a DC filter (see Figure 20). The AC side of the single-phase valve is connected to the AC grid through a converter transformer, and the DC side of the single-phase valve is connected to the DC grid through a DC filter. Each one-way valve includes a switch capacitor bridge arm formed by cascading multiple switch capacitor modules (generally a half-bridge structure, or a full-bridge structure), an H-bridge bridge arm (H-bridge valve string) formed by series connection of power switch devices (generally IGCT or IGBT), and an AC connection reactance.

[0034] In a single-phase valve, the switch capacitor bridge arm of the half-bridge submodule cascade generates a half-wave sine wave, which is then flipped through the H-bridge bridge arm when the voltage passes through zero point to achieve AC output, and connected to the AC grid through the converter transformer; the DC port of the single-phase valve is directly connected in series (that is, the switch capacitor module is cascaded) to form a total DC voltage. The single-phase valve cascade submodule can be decoupled and controlled to operate with a 120° phase difference to achieve three-phase output. The three bridge arms on the DC side can generate a higher level of DC voltage after cascading.

[0035] See also Figure 2The present application provides a modular commutation converter operation test system, including: an energy replenishment device 101, a soft start circuit 102, a load inductor 103, a sampling device (not shown) and a centralized control device (not shown). The energy replenishment device 101 includes multiple DC output terminals, each DC output terminal is correspondingly connected to a test switch capacitor module 201, and multiple test switch capacitor modules 201 are cascaded. The energy replenishment device 101 is used to provide DC power to each test switch capacitor module 201; the first test switch capacitor module 201 in the cascaded multiple test switch capacitor modules 201 is connected to the test H bridge through the soft start circuit 102. valve string 202, the last test switch capacitor module 201 is connected to the test H-bridge valve string 202; the load inductor 103 is connected to the test H-bridge valve string 202; the sampling device is used to collect the operation test parameters of the energy replenishment device 101, the test switch capacitor module 201 and the test H-bridge valve string 202; the centralized control device is connected to the energy replenishment device 101, the soft start circuit 102, the sampling device, the test switch capacitor module 201 and the test H-bridge valve string 202, and the centralized control device is used to control the soft start charging operation of the test switch capacitor module 201 and the test H-bridge valve string 202, and realize the operation test according to the set test parameters and the operation test parameters.

[0036] Specifically, the energy replenishment device 101 is a device for providing DC power to the test switch capacitor module 201 and the test H-bridge valve string 202 under test. In the actual test process, it is necessary to provide DC power to each test switch capacitor module 201 separately, so the energy replenishment device 101 is required to have multiple DC output terminals, and each DC output terminal is connected to a corresponding test switch capacitor module 201. The soft start circuit 102 is a circuit used to realize soft start charging of the test switch capacitor module 201 and the test H-bridge valve string 202. The load reactance 103 is used to simulate the reactance of the AC load connected to the test H-bridge valve string 202.

[0037] The type of sampling device is not unique. Depending on the actual test items, the operating test parameters that need to be detected are also different. Therefore, the sampling devices used will also be different, and they can be configured in combination with the actual scenario. For example, in one embodiment, the operating test parameters include valve section voltage, valve section current, etc. Accordingly, it is necessary to set a voltage collector and a current collector at the test H-bridge valve string 202, and set a voltage collector and a current collector at the cascade structure of the test switch capacitor module 201 to collect the valve section current and valve section voltage.

[0038] It should be noted that in the same running experiment, the number of connected test switch capacitor modules 201 is not unique and is not specifically limited. For example, in a more detailed embodiment, two valve sections are connected in the same test, including a total of 8 test switch capacitor modules 201 and 4 test H-bridge valve strings 202 (a total of 24 H-bridge sub-units).

[0039] In the actual test scenario, the centralized control device first controls the operation of the energy replenishment device 101 and the soft start circuit 102 to charge each test switch capacitor module 201 and the test H-bridge valve string 202 respectively. After the charging of both is completed, the test H-bridge valve string 202 is unlocked, and the test switch capacitor module 201 and the test H-bridge valve string 202 are tested according to the required test items.

[0040] The above-mentioned modular commutation converter operation test system includes an energy replenishment device 101, a soft start circuit 102, a load reactance 103, a sampling device and a centralized control device. The energy replenishment device 101 includes multiple DC output terminals, each of which is connected to a test switch capacitor module 201, so that each test switch capacitor module 201 is individually energized. Under the control of the centralized control device, the energy replenishment device 101 is combined with the soft start circuit 102 to enable the test switch capacitor module 201 and the test H-bridge valve string 202 to soft start and charge, thereby simulating a variety of different working conditions of the modular commutation converter. In this way, the operation test of the modular commutation converter can be realized according to the set test parameters and operation test parameters. Through this solution, the drag test of the test switch capacitor module 201 and the test H-bridge valve string 202 in the modular commutation converter can be realized, thereby filling the gap in the MCC operation test platform, thereby improving the product design capability and quality of the MCC.

[0041] It should be noted that the type of energy supply device 101 is not limited to one type, as long as it can provide DC power to each sample switch capacitor module 201. Figure 3 In one embodiment, the energy compensation device 101 includes a multi-split winding transformer T0 and a rectifier circuit 301, the rectifier circuit 301 is connected to a centralized control device (not shown in the figure), the primary winding of the multi-split winding transformer T0 is used to connect to an AC power supply (not shown in the figure), one secondary winding of the multi-split winding transformer T0 is correspondingly connected to one rectifier circuit 301, and one rectifier circuit 301 is correspondingly connected to one sample switch capacitor module 201.

[0042] Specifically, a multi-split winding transformer T0 refers to a transformer with a single winding on the primary side and a secondary side split into multiple independent winding branches. Each split winding can be operated independently or used in series or parallel combination to meet different load requirements. The rectifier circuit 301 is a circuit that can convert input AC power into DC power. In the solution of this embodiment, the output end of each rectifier circuit 301 is used as a DC output end of the energy replenishment device 101, and a corresponding test switch capacitor module 201 is connected to each of them. In this way, the number of test switch capacitor modules 201 and the test H-bridge valve string 202 in a single test can be effectively increased, thereby improving the test efficiency.

[0043] In another embodiment, a secondary winding of a multi-split winding transformer T0 may be connected to a corresponding rectifier circuit 301, and multiple rectifier circuits 301 may be connected in series to a corresponding test switch capacitor module 201. In this way, the maximum energy compensation voltage of a single test switch capacitor module 201 may be increased to meet the measurement requirements of higher energy compensation voltage scenarios. For example, in one embodiment, the energy compensation branch (secondary winding + rectifier circuit 301 structure) can output 3000Vdc (3 kilovolts DC) when used independently, and can output 6000Vdc (6 kilovolts DC) when the energy compensation branches are used in series in pairs. When the energy compensation branches are used independently, up to 8 channels can be reached, that is, the detection of 8 test switch capacitor modules 201 is realized, and when the energy compensation branches are used in series in pairs, 4 output channels can be realized.

[0044] For further information, see Figure 4 In one embodiment, the energy replenishment device 101 further includes an AC source voltage regulator 302, the primary winding of the multi-split winding transformer T0 is connected to an AC power source through the AC source voltage regulator 302, and the AC source voltage regulator 302 is connected to a centralized control device (not shown).

[0045] Specifically, the AC source voltage regulator 302 refers to a device that can adjust the voltage of AC power to meet the voltage requirements of different loads. In the solution of this embodiment, the energy replenishment device 101 is constructed using the structure of AC source voltage regulator 302 + multi-split winding transformer T0 + rectifier circuit 301, and the AC source voltage regulator 302 is configured with a soft-start resistor, so that an automatic voltage regulation design can be achieved. Specifically, the centralized control device compares the collected DC voltage feedback with the target voltage, and controls the DC side output voltage by controlling the rise and fall time of the AC source voltage regulator 302.

[0046] It should be noted that, in one embodiment, the rectifier circuit 301 includes four groups of rectifier bridges connected in series, so as to reduce the withstand voltage level of a single rectifier bridge and improve the operating reliability of the energy charging device 101.

[0047] See also Figure 5 In one embodiment, the energy replenishment device 101 further includes a voltage stabilizing capacitor C and a discharge resistor Rs connected in parallel, and the rectifier circuit 301 is connected to the sample switch capacitor module 201 via the voltage stabilizing capacitor C and the discharge resistor Rs.

[0048] Specifically, in the solution of this embodiment, the two output ends of the rectifier circuit 301 are respectively connected to the DC side of the test switch capacitor module 201 through a DC bus, and a voltage stabilizing capacitor C and a discharge resistor Rs are provided between the two DC buses. In this way, the stability of the DC voltage output to the test switch capacitor module 201 can be ensured, and the voltage stabilizing capacitor C can be protected by the discharge resistor Rs, and the rapid discharge of the test switch capacitor module 201 can be achieved, thereby improving the test accuracy and test efficiency.

[0049] See also Figure 6 In one embodiment, the system further includes a host computer, and the centralized control device is communicatively connected to the host computer.

[0050] Specifically, the centralized control device serves as the control center of the operation test system, and it can exchange data with the test switch capacitor module 201 and the test H-bridge valve string 202 to achieve normal control. At the same time, the operation test parameters during the test can be obtained through the sampling device, and the operation test can be realized by combining the set test parameters. The centralized control device is connected to the host computer in communication, so that the operation test parameters can be sent to the host computer to realize test monitoring, which is also convenient for subsequent reference.

[0051] See also Figure 6 In one embodiment, the system further includes a wave recording device, and the centralized control device is connected to the wave recording device.

[0052] Specifically, the recording device is an automatic recording device that can quickly and directly record the operating parameters related to the fault when the test system fails. These parameters include but are not limited to electrical quantities such as current, voltage, frequency, and related non-electrical quantities (such as temperature, pressure, etc.). By recording the changes in these parameters, the fault recording device can provide operators with important basis for fault finding, fault location, and fault elimination.

[0053] See also Figure 6 In one embodiment, the system further includes a water cooling device, the centralized control device is connected to the water cooling device, and the water cooling device is used to dissipate heat for the test switch capacitor module 201 and the test H-bridge valve string 202.

[0054] Specifically, the centralized control device can also exchange data with the water cooling device, control start and stop, control flow, set manual / automatic mode, and enable certain functions separately: such as cooling fan, heater, etc. Correspondingly, in one embodiment, the sampling device can also collect conductivity, water flow, inlet and outlet water temperature, ambient temperature, pressure, etc.; or access voltage-type measurement signals, such as valve section voltage, valve section current, port voltage, etc.

[0055] There is no specific limitation on the type of water cooling device. It is mainly used for heat dissipation. It can continuously flow the cooling medium with constant pressure and flow rate through the cooled device (i.e. the test switch capacitor module 201 and the test H-bridge valve series 202) to take away the heat. The heated cooling medium is heat exchanged through the water-air heat exchange equipment and returned to the inlet of the circulation pump after heat exchange. The sealing method of the cooling system and the selection of sealing materials ensure that there is no leakage when the cooling system is operating normally.

[0056] Please refer to Figure 7 and Figure 8 In one embodiment, the soft start circuit 102 includes a soft start resistor R0 and a soft start switch S0 connected in parallel. The soft start switch S0 is connected to a centralized control device (not shown). The centralized control device is also used to control the energy replenishment device 101 to charge the sample switch capacitor module 201, and when the sample switch capacitor module 201 is fully charged, the soft start switch S0 is controlled to be turned off to charge the sample H-bridge valve string 202 through the soft start resistor R0; when the sample H-bridge valve string 202 is charged to a set voltage value, the soft start switch S0 is controlled to be turned on to bypass the soft start resistor R0.

[0057] Specifically, the soft start circuit 102 of this embodiment includes a soft start resistor and a soft start switch in parallel. During the soft start stage of charging, the soft start switch is turned off, and the current flows into the test H-bridge valve string 202 through the soft start resistor. Taking the simultaneous testing of 8 test switch capacitor modules 201 as an example, the 8 energy compensation branches charge the 8 test switch capacitor modules 201 respectively. After the configuration of the test switch capacitor module 201 is completed, it can execute the charging instruction and charge each H-bridge sub-unit through the soft start resistor R0. After each sub-unit is powered, active charging can be started. When the active charging reaches the set voltage value, the H-bridge sub-unit can be unlocked. After the H-bridge sub-unit is unlocked, the soft start resistor R0 is bypassed.

[0058] In one embodiment, the test H-bridge valve string 202 is charged through the soft-start resistor R0, including: after each H-bridge sub-unit of the test H-bridge valve string 202 is powered, patrolling each H-bridge sub-unit until the voltage of each H-bridge sub-unit reaches a set voltage value.

[0059] Specifically, in actual scenarios, considering that the H-bridge is a series connection of multiple IGCT units, voltage balance must be controlled during the charging process, and voltage divergence will cause a certain level of IGCT units to fail to work properly. Therefore, this embodiment adopts a method of controlling the on and off of each H-bridge sub-unit in a round-robin manner to achieve voltage balancing operation and ensure that each H-bridge sub-unit operates normally during the charging process.

[0060] In one embodiment, the operation test items include: module communication test, minimum DC voltage test, overcurrent shutdown test, maximum current continuous operation capability test, maximum short-time overcurrent capability test, maximum voltage continuous operation capability test, fault bypass test, current flow test, normal temperature double pulse test, short circuit test, static withstand voltage test and at least one of the loss measurement test.

[0061] Specifically, the module communication test is the communication capability test of each test switch capacitor module 201, the test H-bridge valve string 202 and the sampling device, including communication detection and single module wave detection. The minimum DC voltage test refers to the minimum DC voltage (that is, 0.2pu, the deviation is not more than 2%, pu is the rated voltage) under which the entire system can operate normally, trigger the power device and detect the feedback signal (unlock operation), and the operation duration is not less than 10 minutes. The overcurrent shutdown test refers to the test switch capacitor module 201 realizing the shutdown conversion of a specific current under a certain voltage.

[0062] When testing the maximum current continuous operation capability, the test requirements must reach the worst conditions during the operation of the modular commutated converter. It is necessary to reproduce the maximum values ​​of all parameters: continuous power device junction temperature (value), turn-on current (value), turn-off voltage (value), du / dt (value and figure), di / dt (value and figure), temperature of continuous snubber components (if any) (value), continuous on and off voltage and current (value).

[0063] During the maximum short-time overcurrent capability test, the valve assembly under test (i.e. the pair-drag structure of the test switch capacitor module 201 and the test H-bridge valve string 202) must first reach thermal stability under the maximum current continuous operation capability test (i.e. 1.05pu, operation time ≥ 120min), and then start the maximum temporary overload operation capability test (i.e. 1.2pu, 10 seconds). After the test is completed, the maximum current continuous operation capability test (i.e. 1.05pu) must be continued for 10 minutes to check whether the test causes damage.

[0064] Maximum voltage continuous operation capability test: 1) The test requirements must meet the worst conditions during the operation of the modular commutation converter. It is necessary to reproduce the maximum values ​​of all parameters in the test: continuous power device junction temperature (numerical value), turn-on current (numerical value), turn-off voltage (numerical value), du / dt (numerical value and graph), di / dt (numerical value and graph), continuous buffer element (if any) temperature (numerical value), continuous on and off voltage and current (numerical value); 2) During the test, thermal equilibrium should be achieved at least under the maximum current continuous operation condition, and the actual measured maximum values ​​of the above parameters meet the design requirements.

[0065] The fault bypass test simulates the module operation failure and detects whether the bypass switch operates normally. The room temperature double pulse test includes single pulse and double pulse tests of the device. The short circuit test checks whether the power device (the power switch in the test switch capacitor module 201 and the test H-bridge valve string 202) and related circuits can operate reliably under short circuit conditions, whether the voltage, current, du / dt and di / dt maximum values ​​in the short circuit test meet the design requirements, and whether the device is damaged within the safety margin.

[0066] The static withstand voltage test is to detect the insulation withstand voltage capability of the module. The loss measurement test is to record the module inlet and outlet water temperatures during the maximum current continuous operation test, and obtain the power module loss by measuring the module inlet and outlet water temperature rise.

[0067] In the description of this specification, the description with reference to the terms "some embodiments", "other embodiments", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic description of the above terms does not necessarily refer to the same embodiment or example.

[0068] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0069] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be construed as limiting the scope of the patent application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent application shall be subject to the attached claims.

Claims

1. A modular commutation converter operation test system, characterized in that: include: The energy replenishment device comprises a plurality of DC output terminals, each of which is connected to a corresponding sample switch capacitor module, and a plurality of the sample switch capacitor modules are cascaded, and the energy replenishment device is used to provide DC power to each of the sample switch capacitor modules; A soft start circuit, wherein the first test switch capacitor module of the cascaded multiple test switch capacitor modules is connected to the test H-bridge valve string through the soft start circuit, and the last test switch capacitor module is connected to the test H-bridge valve string; A load reactance connected to the H-bridge valve string of the test product; A sampling device, used to collect operating test parameters of the energy replenishment device, the test switch capacitor module and the test H-bridge valve string; The centralized control device is connected to the energy replenishment device, the soft start circuit, the sampling device, the test switch capacitor module and the test H-bridge valve string. The centralized control device is used to control the soft start charging operation of the test switch capacitor module and the test H-bridge valve string, and to implement the operation test according to the set test parameters and the operation test parameters.

2. The modular commutation converter operation test system according to claim 1, characterized in that: The energy compensation device includes a multi-split winding transformer and a rectifier circuit, the rectifier circuit is connected to the centralized control device, the primary winding of the multi-split winding transformer is used to connect to an AC power supply, one secondary winding of the multi-split winding transformer is correspondingly connected to one of the rectifier circuits, and one of the rectifier circuits is correspondingly connected to one of the sample switch capacitor modules.

3. The modular commutation converter operation test system according to claim 2, characterized in that: The energy replenishment device also includes an AC source voltage regulator, the primary winding of the multi-split winding transformer is connected to the AC power source through the AC source voltage regulator, and the AC source voltage regulator is connected to the centralized control device.

4. The modular commutation converter operation test system according to claim 3, characterized in that: The energy replenishment device further includes a voltage-stabilizing capacitor and a discharge resistor connected in parallel, and the rectifier circuit is connected to the sample switch capacitor module via the voltage-stabilizing capacitor and the discharge resistor.

5. The modular commutation converter operation test system according to any one of claims 1 to 4, characterized in that: The system also includes a host computer, and the centralized control device is communicatively connected to the host computer.

6. The modular commutation converter operation test system according to any one of claims 1 to 4, characterized in that: The system also includes a wave recording device, and the centralized control device is connected to the wave recording device.

7. The modular commutation converter operation test system according to any one of claims 1 to 4, characterized in that: The system further comprises a water cooling device, the centralized control device is connected to the water cooling device, and the water cooling device is used to dissipate heat for the test switch capacitor module and the test H-bridge valve string.

8. The modular commutation converter operation test system according to any one of claims 1 to 4, characterized in that: The soft-start circuit includes a soft-start resistor and a soft-start switch connected in parallel, the soft-start switch is connected to the centralized control device, and the centralized control device is also used to control the energy replenishment device to charge the sample switch capacitor module, and when the charging of the sample switch capacitor module is completed, control the soft-start switch to turn off so as to charge the sample H-bridge valve string through the soft-start resistor; when the sample H-bridge valve string is charged to a set voltage value, control the soft-start switch to turn on to bypass the soft-start resistor.

9. The modular commutation converter operation test system according to claim 8, characterized in that: The charging of the test H-bridge valve string through the soft-start resistor includes: after each H-bridge subunit of the test H-bridge valve string is powered, patrolling the H-bridge subunits until the voltage of each H-bridge subunit reaches a set voltage value.

10. The modular commutation converter operation test system according to any one of claims 1 to 4, characterized in that: The operation test items include: module communication test, minimum DC voltage test, overcurrent shutdown test, maximum current continuous operation capability test, maximum short-time overcurrent capability test, maximum voltage continuous operation capability test, fault bypass test, current flow test, double pulse test at room temperature, short circuit test, static withstand voltage test and at least one of the loss measurement test.

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