Short circuit test system of inverter
By setting up contactors and circuit breakers in the inverter short-circuit test system, rapid short-circuit testing without manual wiring can be achieved, solving the problems of long testing time and high risk in the existing technology, and improving testing efficiency and safety.
Patent Information
- Application Number
- CN202422679369.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-01
- Publication Date
- 2025-12-02
- Estimated Expiration
- 2034-11-01
AI Technical Summary
Existing short-circuit testing methods for inverters are time-consuming and dangerous, requiring manual wiring.
Design a short-circuit testing system for inverters. By setting up a first contactor, a circuit breaker, and a second contactor, the short-circuit point can be quickly switched without manual wiring. The automation level can be improved by using remote control of the circuit breaker.
It improves the efficiency of short-circuit testing, ensures the safety of the testing process, reduces the danger to the power grid and equipment, and enhances the versatility and ease of operation of the system.
Smart Images
Figure CN223624397U_ABST
Abstract
Description
Technical Field
[0001] This application belongs to the field of inverter technology, and in particular relates to a short-circuit test system for inverters. Background Technology
[0002] AC short-circuit protection is a crucial part of inverter protection functions, requiring extensive testing and verification. Related technologies primarily employ manual wiring to switch and perform short-circuit tests. However, this method is time-consuming and involves short-circuiting the power grid and grid simulation equipment, posing a significant risk. Utility Model Content
[0003] This application aims to address at least one of the technical problems existing in the prior art. To this end, this application proposes a short-circuit testing system for inverters that eliminates the need for manual wiring. By closing or opening components in the short-circuit testing system, the short-circuit point can be switched, achieving rapid switching, improving the efficiency of short-circuit testing, and ensuring the safety of the short-circuit testing process.
[0004] In a first aspect, this application provides a short-circuit testing system for an inverter, wherein the inverter under test is connected to a phase line of the power grid and is respectively connected to the neutral line and ground line of the power grid; the short-circuit testing system for the inverter is connected between the power grid and an islanded testing device; the system includes:
[0005] The first contactor is located on a phase line of the power grid and is located between the inverter under test and the power grid.
[0006] A circuit breaker is disposed on the side of the first contactor away from the power grid; the circuit breaker includes a first circuit breaker and a second circuit breaker, the first circuit breaker being connected to the phase line, and the second circuit breaker being connected to the neutral line and the ground line respectively.
[0007] A second contactor is disposed between the first circuit breaker and the second circuit breaker; the opening and closing states of the first contactor and the second contactor are set to be opposite to each other;
[0008] An oscilloscope is connected to both the inverter under test and the first output terminal of the second contactor. The first output terminal of the second contactor outputs a short-circuit trigger signal. The oscilloscope outputs the electrical signal waveform of the inverter under test based on the short-circuit trigger signal.
[0009] According to the short-circuit test system for inverters provided in the embodiments of this application, by setting a first contactor, a circuit breaker, and a second contactor in the short-circuit test system for inverters, the circuit of the inverter to be tested can be short-circuited by closing or opening the first contactor, circuit breaker, and second contactor on the circuit to be tested of the inverter under test. No manual wiring is required. The short-circuit point can be switched by closing or opening the components in the short-circuit test system of the inverter, realizing rapid switching, improving the efficiency of short-circuit testing, and ensuring the safety of the short-circuit test process.
[0010] According to the short-circuit test system for an inverter provided in the embodiments of this application, the first contactor includes at least one main contact, and the at least one main contact is arranged in a one-to-one correspondence with the phase lines included in the power grid.
[0011] According to the short-circuit test system for inverters provided in the embodiments of this application, the at least one main contact includes:
[0012] The first main contact is located on phase A of the power grid;
[0013] The second main contact is located on the B-phase line of the power grid;
[0014] The third main contact is located on the C-phase line of the power grid.
[0015] According to the short-circuit test system for an inverter provided in the embodiments of this application, the first circuit breaker includes at least one sub-circuit breaker, and the at least one sub-circuit breaker is configured in a one-to-one correspondence with the phase lines included in the power grid.
[0016] According to the short-circuit test system for inverters provided in the embodiments of this application, the at least one sub-circuit breaker includes:
[0017] The first sub-circuit breaker is installed on phase A of the power grid;
[0018] The second sub-circuit breaker is installed on the B phase line of the power grid;
[0019] The third sub-circuit breaker is installed on the C-phase line of the power grid.
[0020] According to the short-circuit test system for an inverter provided in the embodiments of this application, the second circuit breaker includes:
[0021] The fourth sub-circuit breaker is connected to the neutral line of the power grid;
[0022] The fifth sub-circuit breaker is connected to the ground wire of the power grid;
[0023] The fourth sub-circuit breaker and the fifth sub-circuit breaker are respectively connected to the second output terminal of the second contactor.
[0024] According to the short-circuit test system for an inverter provided in the embodiments of this application, the second contactor includes at least one main contact, and the at least one main contact is arranged in a one-to-one correspondence with the phase lines included in the power grid.
[0025] According to the short-circuit test system for inverters provided in the embodiments of this application, the at least one main contact includes:
[0026] The fourth main contact is located on phase A of the power grid;
[0027] The fifth main contact is located on the B-phase line of the power grid;
[0028] The sixth main contact is located on the C-phase line of the power grid.
[0029] According to the short-circuit test system for inverters provided in the embodiments of this application, the circuit breaker is a remotely controlled circuit breaker.
[0030] According to the short-circuit test system for an inverter provided in the embodiments of this application, at least one of the first contactor, the circuit breaker, and the second contactor is a switching device.
[0031] The above-described one or more technical solutions in the embodiments of this application have at least one of the following technical effects:
[0032] By setting up a first contactor, a circuit breaker, and a second contactor in the short-circuit test system of the inverter, the circuit of the inverter under test can be short-circuited by closing or opening the first contactor, circuit breaker, and second contactor on the circuit to be tested. No manual wiring is required. The short-circuit point can be switched by closing or opening the components in the short-circuit test system of the inverter, realizing rapid switching, improving the efficiency of short-circuit testing, and ensuring the safety of the short-circuit test process.
[0033] Furthermore, by setting one or more main contacts in the first contactor, the first contactor can be flexibly set to all phase lines included in the circuit where each phase line of the inverter under test is connected to the grid, based on the actual situation of the power grid. This increases the application scenarios of the inverter's short-circuit test system and improves the versatility of short-circuit testing.
[0034] Furthermore, by setting a first sub-circuit breaker, a second sub-circuit breaker, and a third sub-circuit breaker in the first circuit breaker, and by setting each sub-circuit breaker in correspondence with the phase lines included in the power grid, the on / off state of each sub-circuit breaker can be effectively controlled to control the on / off state of each phase circuit of the inverter under test. The control logic is simple and easy to operate.
[0035] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description
[0036] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:
[0037] Figure 1 This is one of the structural schematic diagrams of the short-circuit test system for the inverter provided in the embodiments of this application;
[0038] Figure 2 This is a second schematic diagram of the short-circuit test system for the inverter provided in the embodiments of this application;
[0039] Figure 3 This is the third schematic diagram of the short-circuit test system for the inverter provided in the embodiments of this application.
[0040] Figure label:
[0041] Inverter under test 110; First contactor KM1; Circuit breaker 120; First circuit breaker 121; Second circuit breaker 122;
[0042] Second contactor KM2; First sub-circuit breaker QF1; Second sub-circuit breaker QF2; Third sub-circuit breaker QF3;
[0043] Fourth sub-circuit breaker QF4; Fifth sub-circuit breaker QF5; Power grid 130; Islanding test equipment 140. Detailed Implementation
[0044] The technical solutions of the embodiments of this application will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application are within the scope of protection of this application.
[0045] The terms "first," "second," etc., used in the specification and claims of this application are used to distinguish similar objects and not to describe a specific order or sequence. It should be understood that such use of data can be interchanged where appropriate so that embodiments of this application can be implemented in orders other than those illustrated or described herein, and the objects distinguished by "first," "second," etc., are generally of the same class and the number of objects is not limited; for example, a first object can be one or more. Furthermore, in the specification and claims, "and / or" indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following objects are in an "or" relationship.
[0046] 1. In the description of this application, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.
[0047] 2. In the description of this application, "multiple" means two or more.
[0048] The short-circuit test system for inverters provided in this application will be described in detail below with reference to the accompanying drawings, through specific embodiments and application scenarios.
[0049] like Figure 1 As shown, the short-circuit test system for the inverter may include: a first contactor KM1, a circuit breaker 120, a second contactor KM2, and an oscilloscope.
[0050] In this embodiment, the inverter under test 110 can be set on the phase line of the power grid 130 and connected to the neutral line and ground line of the power grid 130 respectively.
[0051] The phase lines of the power grid 130 can be determined based on the actual situation of the power grid 130. For example, the power grid 130 may include single phase (i.e., the power grid 130 includes phase A), two phase (i.e., the power grid 130 includes phase A and phase B), and three phase (i.e., the power grid 130 includes phase A, phase B, and phase C), etc. This application does not limit them.
[0052] The inverter's short-circuit test system can be connected between the power grid 130 and the islanded test equipment 140.
[0053] The inverter under test 110 is the inverter that needs to be tested.
[0054] The islanded test equipment 140 may include resistors, inductors, and capacitors.
[0055] Both the first contactor KM1 and the second contactor KM2 are devices that regulate the on / off state of the circuit by controlling electrical signals such as voltage and current in the control circuit.
[0056] The first contactor KM1 and the second contactor KM2 are positioned differently in the inverter's short-circuit test system.
[0057] The first contactor KM1 can be installed on the phase line of the power grid 130, and the first contactor KM1 can be installed between the inverter under test 110 and the power grid 130.
[0058] Circuit breaker 120 is a device used to disconnect or connect circuits.
[0059] The circuit breaker 120 can be installed on the side of the first contactor KM1 away from the power grid 130.
[0060] Circuit breaker 120 may include a first circuit breaker 121 and a second circuit breaker 122.
[0061] The first circuit breaker 121 is connected to the phase line.
[0062] The second circuit breaker 122 is connected to the neutral line and the ground line respectively.
[0063] In some embodiments, circuit breaker 120 may be a remotely controlled circuit breaker 120.
[0064] In this embodiment, when the circuit breaker 120 is a remotely controlled circuit breaker 120, the opening and closing state of the circuit breaker 120 can be remotely controlled to achieve automated short-circuit testing.
[0065] For example, such as Figure 1 The circuit breaker 120 shown is configured as a remote control circuit breaker 120. During the short circuit test, the user does not need to be at the location of the inverter under test 110 to perform the short circuit test by controlling the opening and closing state of the circuit breaker 120.
[0066] According to the short-circuit test system for inverters provided in the embodiments of this application, by setting the circuit breaker 120 as a remote control circuit breaker 120, the opening and closing state of the circuit breaker 120 can be remotely controlled during the short-circuit test. After the circuit breaker 120 is opened or closed, the short-circuit test can be performed automatically, thereby improving the efficiency of the short-circuit test and enhancing the user experience.
[0067] The second contactor KM2 can be installed between the first circuit breaker 121 and the second circuit breaker 122.
[0068] The opening and closing states of the first contactor KM1 and the second contactor KM2 can be set to opposite states.
[0069] In actual operation, when the first contactor KM1 is closed, the second contactor KM2 is open.
[0070] When the first contactor KM1 is open, the second contactor KM2 is closed.
[0071] like Figure 3 As shown, in some embodiments, the first contactor KM1 and the second contactor KM2 can be linked together.
[0072] In this embodiment, the linkage connection may include, but is not limited to, any feasible linkage method among belt linkage, chain drive and gear drive, and this application does not limit it.
[0073] The first contactor KM1 and the second contactor KM2 can also be linked together through auxiliary contacts.
[0074] Continue to refer to Figure 2 The coil corresponding to the first contactor KM1 can be connected to the second contactor KM2, and the coil corresponding to the second contactor KM2 can be connected to the first contactor KM1, so that the first contactor KM1 and the second contactor KM2 can be linked and thus interlocked.
[0075] According to the short-circuit test system for inverters provided in the embodiments of this application, by setting an interlocking connection device between the first contactor KM1 and the second contactor KM2, the opening and closing states of the first contactor KM1 and the second contactor KM2 can be set to opposite states. When the first contactor KM1 is closed, the second contactor KM2 is opened, or when the first contactor KM1 is opened, the second contactor KM2 is closed, thus ensuring the safety of the power grid 130 and the safety of the short-circuit test process.
[0076] An oscilloscope is an electronic measuring instrument that can convert the information contained in an electrical signal into an image, so that users can analyze the information contained in the electrical signal.
[0077] An oscilloscope can measure information such as voltage and current in a circuit.
[0078] An oscilloscope may include voltage sampling channels and current sampling channels.
[0079] Continue to refer to Figure 1 When the power grid 130 includes three phases, the inverter under test 110 can be connected to the three phases of the power grid 130, and the oscilloscope can measure the voltage and current of the A-phase circuit, B-phase circuit and C-phase circuit of the inverter under test 110 respectively.
[0080] The oscilloscope is connected to the first output terminal of the inverter under test 110 and the second contactor KM2, respectively.
[0081] In some embodiments, the second contactor KM2 may also include auxiliary contacts.
[0082] In this embodiment, such as Figure 3 As shown, when the second contactor KM2 is closed, the auxiliary contact will also close.
[0083] The auxiliary contact is connected to the first output terminal.
[0084] The first output terminal of the second contactor KM2 can output a short-circuit trigger signal.
[0085] The short-circuit trigger signal is a signal that indicates a short circuit in the circuit.
[0086] In the event of a short circuit, the short-circuit trigger signal can generate a change from a low level to a high level.
[0087] In the event of a short circuit, the short-circuit trigger signal can also produce a change from a high level to a low level.
[0088] The oscilloscope can output the electrical signal waveform of the inverter under test 110 based on the short-circuit trigger signal.
[0089] The electrical signal waveform is the waveform of the electrical signal in the circuit measured by the oscilloscope during the short-circuit test.
[0090] Electrical signals can be current, voltage, and power, etc.
[0091] In actual operation, based on the actual need for short-circuit testing, the circuit breaker 120 can be closed to perform the short-circuit test. During the test, the anti-islanding function of the inverter under test 110 can be turned off, and the islanding test equipment 140 can be matched at the preset power to make the inverter under test 110 operate in islanded state. After the matching is completed, the first contactor KM1 is disconnected and the second contactor KM2 is closed. At this time, the oscilloscope can measure the electrical signal waveform of the short-circuit circuit. Users can analyze the electrical signal waveform based on actual usage requirements, such as the protection time of the inverter under test 110 and the peak current during the short circuit.
[0092] The preset power is the power that the inverter under test 110 needs to reach during the short-circuit test.
[0093] The specific value of the preset power can be based on user-defined settings or determined based on actual conditions; this application does not impose any restrictions.
[0094] During the research and development process, researchers discovered that the relevant technologies primarily rely on manually switching short-circuit points for short-circuit testing. However, this method is time-consuming and requires short-circuiting both the mains circuit 130 and its simulation equipment, posing a significant risk.
[0095] This application sets up a first contactor KM1, a circuit breaker 120, and a second contactor KM2 in the short-circuit test system of the inverter. The opening and closing of the first contactor KM1, the circuit breaker 120, and the second contactor KM2 can be combined to select the circuit to be tested for short circuit. Furthermore, by closing or opening the first contactor KM1, the circuit breaker 120, and the second contactor KM2 on the circuit to be tested, the circuit of the inverter under test can be short-circuited. No manual wiring is required. The short-circuit point can be switched by closing or opening the components in the short-circuit test system of the inverter, realizing rapid switching and improving the efficiency of short-circuit testing.
[0096] Furthermore, by connecting the inverter's short-circuit test system between the grid 130 and the islanded test equipment 140, there is no need to short-circuit the real grid 130 or the grid 130 simulation equipment, thus ensuring the safety of the short-circuit test.
[0097] According to the short-circuit test system for inverters provided in the embodiments of this application, by setting a first contactor KM1, a circuit breaker 120, and a second contactor KM2 in the short-circuit test system for inverters, the circuit of the inverter to be tested can be short-circuited by closing or opening the first contactor KM1, the circuit breaker 120, and the second contactor KM2 on the circuit to be tested of the inverter 110. No manual wiring is required. The short-circuit point can be switched by closing or opening the components in the short-circuit test system of the inverter, realizing rapid switching, improving the efficiency of short-circuit testing, and ensuring the safety of the short-circuit test process.
[0098] In some embodiments, at least one of the first contactor KM1, the circuit breaker 120, and the second contactor KM2 may be a switching device.
[0099] In this embodiment, the first contactor KM1, the circuit breaker 120, and the second contactor KM2 can be conventional switching devices for controlling the opening and closing of control circuits.
[0100] In actual implementation, one or more of the first contactor KM1, circuit breaker 120, and second contactor KM2 can be replaced with switching devices based on actual usage requirements.
[0101] For example, replace circuit breaker 120 with a switchgear.
[0102] For example, the first contactor KM1 and the second contactor KM2 can be replaced with switching devices.
[0103] According to the short-circuit test system for inverters provided in the embodiments of this application, by replacing one or more of the first contactor KM1, circuit breaker 120 and second contactor KM2 with switching devices, the configuration cost of the short-circuit test system for inverters can be effectively reduced while ensuring the short-circuit test requirements.
[0104] In some embodiments, the first contactor KM1 may include at least one main contact.
[0105] In this embodiment, the main contact is a component that controls whether the circuit is turned on or off.
[0106] At least one main contact is provided in a one-to-one correspondence with the phase wires included in the power grid 130.
[0107] In the case where the power grid 130 includes two phases, the first contactor KM1 may include two main contacts.
[0108] Each main contact is set up in a one-to-one correspondence with the two corresponding phase lines of the power grid 130.
[0109] In the case that the power grid 130 includes three phases, the first contactor KM1 may include three main contacts.
[0110] Each main contact is set to correspond one-to-one with the phase line of the three-phase power grid 130.
[0111] According to the short-circuit test system for inverters provided in the embodiments of this application, by setting one or more main contacts in the first contactor KM1, the first contactor KM1 can be flexibly set in the circuit where each phase line of the inverter under test 110 is connected to the power grid 130 based on the actual situation of the power grid 130, thereby increasing the application scenarios of the short-circuit test system for inverters and improving the versatility of short-circuit testing.
[0112] The following description uses a three-phase power grid 130 as an example to illustrate the main contacts of the first contactor KM1 and the connection method of each main contact.
[0113] Continue to refer to Figure 1 In some embodiments, at least one main contact may include: a first main contact, a second main contact, and a third main contact.
[0114] In this embodiment, the first main contact can be located on phase A of the power grid 130.
[0115] The second main contact can be set on phase B of the power grid 130.
[0116] The third main contact can be set on the C phase line of the power grid 130.
[0117] In actual operation, each main contact can close or open the main contact corresponding to the test circuit based on the actual situation of the short circuit test.
[0118] For example, during the short circuit testing of phase A and phase B circuits of inverter 110 under test, the first main contact and the second main contact can be disconnected respectively.
[0119] For example, during the short circuit testing of phase B and phase C circuits of the inverter under test, the second and third main contacts can be disconnected respectively.
[0120] According to the short-circuit test system for inverters provided in the embodiments of this application, by setting a first main contact, a second main contact, and a third main contact in the first contactor KM1, and setting each main contact to correspond one-to-one with the phase lines included in the power grid 130, the on / off state of each main contact can be effectively controlled by controlling the on / off state of each phase circuit connected between the inverter under test 110 and the power grid 130. The control logic is simple and easy to operate.
[0121] In some embodiments, the first circuit breaker 121 includes at least one sub-circuit breaker.
[0122] In this embodiment, the sub-circuit breaker is a component that cuts off or connects the circuit.
[0123] At least one sub-circuit breaker is installed in a one-to-one correspondence with the phase lines included in the power grid 130.
[0124] The actual number of sub-circuit breakers can be determined based on the phase lines included in the power grid 130.
[0125] For example, if the power grid 130 includes two phases, the first circuit breaker 121 may include two sub-circuit breakers, each sub-circuit breaker being configured in a one-to-one correspondence with the two phases included in the power grid 130.
[0126] For example, if the power grid 130 includes three phases, the first circuit breaker 121 may include three sub-circuit breakers, each sub-circuit breaker being configured in a one-to-one correspondence with the three phases included in the power grid 130.
[0127] According to the short-circuit test system for inverters provided in the embodiments of this application, by setting one or more sub-circuit breakers in the first circuit breaker 121, the first circuit breaker 121 can be flexibly set in the circuits where the phase lines connecting the inverter under test 110 and the power grid 130 are located, based on the actual situation of the power grid 130, thereby increasing the application scenarios of the short-circuit test system for inverters and improving the versatility of short-circuit testing.
[0128] The following description uses a three-phase power grid 130 as an example to illustrate the sub-circuit breakers included in the first circuit breaker 121 and the connection method of each sub-circuit breaker.
[0129] Continue to refer to Figure 1 In some embodiments, at least one sub-circuit breaker may include: a first sub-circuit breaker QF1, a second sub-circuit breaker QF2, and a third sub-circuit breaker QF3.
[0130] In this embodiment, the first sub-circuit breaker QF1 is installed on phase A of the power grid 130.
[0131] The second sub-circuit breaker QF2 is installed on phase B of power grid 130.
[0132] The third sub-circuit breaker QF3 is installed on phase C of the power grid 130.
[0133] In actual operation, each sub-circuit breaker can close or open the sub-circuit breaker corresponding to the test circuit based on the actual situation of the short-circuit test.
[0134] For example, during the short circuit testing of phase A and phase B circuits of the inverter under test 110, the first sub-circuit breaker QF1 and the second sub-circuit breaker QF2 can be disconnected respectively.
[0135] For example, during the short circuit testing of phase B and phase C of the inverter under test, the second sub-circuit breaker QF2 and the third sub-circuit breaker QF3 can be disconnected respectively.
[0136] According to the short-circuit test system for inverters provided in the embodiments of this application, by setting a first sub-circuit breaker QF1, a second sub-circuit breaker QF2, and a third sub-circuit breaker QF3 in the first circuit breaker 121, and setting each sub-circuit breaker in correspondence with the phase lines included in the power grid 130, the on / off state of each phase circuit of the inverter under test 110 can be effectively controlled by the opening and closing state of each sub-circuit breaker. The control logic is simple and easy to operate.
[0137] In some embodiments, the second circuit breaker 122 may include a fourth sub-circuit breaker QF4 and a fifth sub-circuit breaker QF5.
[0138] In this embodiment, the fourth sub-circuit breaker QF4 is connected to the neutral line of the power grid 130.
[0139] The fifth sub-circuit breaker QF5 is connected to the ground wire of the power grid 130.
[0140] The fourth sub-circuit breaker QF4 and the fifth sub-circuit breaker QF5 are respectively connected to the second output terminal of the second contactor KM2.
[0141] In actual operation, the second output terminal of the second contactor KM2 is the output terminal corresponding to each of the main contacts included in the second contactor KM2.
[0142] Each sub-circuit breaker can close or open the fourth sub-circuit breaker QF4 or the fifth sub-circuit breaker QF5 based on the actual situation of the short-circuit test.
[0143] For example, during the testing of the 110A phase circuit and neutral short circuit of the inverter under test, the first sub-circuit breaker QF1 and the fourth sub-circuit breaker QF4 can be disconnected respectively.
[0144] For example, during the testing of the 110A phase circuit and ground short circuit of the inverter under test, the first sub-circuit breaker QF1 and the fifth sub-circuit breaker QF5 can be disconnected respectively.
[0145] According to the short-circuit test system for inverters provided in the embodiments of this application, a fourth sub-circuit breaker QF4 and a fifth sub-circuit breaker QF5 are respectively set in the second circuit breaker 122. The fourth sub-circuit breaker QF4 is connected to the neutral line of the power grid 130, and the fourth sub-circuit breaker QF4 is connected to the ground line of the power grid 130. The opening and closing states of each sub-circuit breaker can effectively control the connection and disconnection of each phase circuit of the inverter under test 110 with the neutral line or ground line. The control logic is simple and easy to operate.
[0146] In some embodiments, the second contactor KM2 may include at least one main contact.
[0147] In this embodiment, when the power grid 130 includes two phases, the second contactor KM2 may include two main contacts.
[0148] Each main contact is set up in a one-to-one correspondence with the two corresponding phase lines of the power grid 130.
[0149] In the case that the power grid 130 includes three phases, the second contactor KM2 may include three main contacts.
[0150] Each main contact is set to correspond one-to-one with the phase line of the three-phase power grid 130.
[0151] According to the short-circuit test system for inverters provided in the embodiments of this application, by setting one or more main contacts in the second contactor KM2, the second contactor KM2 can be flexibly set in the circuit where each phase line of the inverter under test 110 is connected to the power grid 130 based on the actual situation of the power grid 130, thereby increasing the application scenarios of the short-circuit test system for inverters and improving the versatility of short-circuit testing.
[0152] Continue to refer to Figure 1 In some embodiments, at least one main contact may include: a fourth main contact, a fifth main contact, and a sixth main contact.
[0153] In this embodiment, the fourth main contact is located on phase A of the power grid 130.
[0154] The fifth main contact is located on phase B of the power grid 130.
[0155] The sixth main contact is located on the C phase line of the power grid 130.
[0156] In actual operation, each main contact can close or open the main contact corresponding to the test circuit based on the actual situation of the short circuit test.
[0157] For example, during the short circuit testing of phase A and phase B circuits of the inverter under test 110, the fourth and fifth main contacts can be disconnected respectively.
[0158] For example, during the short circuit testing of phase B and phase C circuits of the inverter under test, the fifth and sixth main contacts can be disconnected respectively.
[0159] The following explanation uses the example of testing a short circuit in phase A and phase B of the inverter under test (110).
[0160] Continue to refer to Figure 1 When it is necessary to test the short circuit of phase A and phase B of inverter 110 under test, the first sub-circuit breaker QF1 and the second sub-circuit breaker QF2 are closed. Then, the anti-islanding function of inverter 110 under test is turned off, and the islanding test equipment 140 is matched based on the preset power. After the islanding test equipment 140 is successfully matched, the first contactor KM1 and the second contactor KM2 are disconnected. At the same time as the first contactor KM1 is disconnected, the fourth contactor will be closed. At the same time as the second contactor KM2 is disconnected, the fifth contactor will also be closed.
[0161] If the islanded test device 140 fails to match, the inverter under test 110 will automatically shut down for protection. At this time, the preset power value can be updated, and the islanded test device 140 can be matched again. This step is repeated until the islanded test device 140 is successfully matched.
[0162] With the first contactor KM1 and the second contactor KM2 disconnected and the fourth contactor and the fifth contactor closed, the A-phase circuit and the B-phase circuit of the inverter under test 110 are short-circuited. At this time, the oscilloscope will measure the three-phase output current of the inverter under test 110 and obtain the electrical signal waveform, such as the current waveform. The obtained current waveform can then be analyzed to obtain information such as the protection duration and peak current of the inverter under test 110 during the short-circuit test.
[0163] According to the short-circuit test system for inverters provided in the embodiments of this application, by setting a fourth main contact, a fifth main contact, and a sixth main contact in the second contactor KM2, and setting each main contact to correspond one-to-one with the phase lines included in the power grid 130, the on / off state of each main contact can be effectively controlled by controlling the on / off state of each phase circuit connected between the inverter under test 110 and the power grid 130. The control logic is simple and easy to operate.
[0164] The embodiments of this application have been described above with reference to the accompanying drawings. However, this application is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of this application without departing from the spirit and scope of the claims, and all of these forms are within the protection scope of this application.
[0165] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.
[0166] Although embodiments of this application have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of this application, the scope of which is defined by the claims and their equivalents.
Claims
1. A short-circuit test system for an inverter, characterized in that, The inverter under test is connected to a phase line of the power grid and is also connected to the neutral and ground lines of the power grid. The short-circuit test system for the inverter is connected between the power grid and the islanded test equipment. The short-circuit test system for the inverter includes: The first contactor is located on a phase line of the power grid and is located between the inverter under test and the power grid. A circuit breaker is disposed on the side of the first contactor away from the power grid; the circuit breaker includes a first circuit breaker and a second circuit breaker, the first circuit breaker being connected to the phase line, and the second circuit breaker being connected to the neutral line and the ground line respectively. A second contactor is disposed between the first circuit breaker and the second circuit breaker; the opening and closing states of the first contactor and the second contactor are set to be opposite to each other; An oscilloscope is connected to both the inverter under test and the first output terminal of the second contactor. The first output terminal of the second contactor outputs a short-circuit trigger signal. The oscilloscope outputs the electrical signal waveform of the inverter under test based on the short-circuit trigger signal.
2. The short-circuit test system for an inverter according to claim 1, characterized in that, The first contactor includes at least one main contact, which is configured in a one-to-one correspondence with the phase lines included in the power grid.
3. The short-circuit test system for an inverter according to claim 2, characterized in that, The at least one main contact includes: The first main contact is located on phase A of the power grid; The second main contact is located on the B-phase line of the power grid; The third main contact is located on the C-phase line of the power grid.
4. The short-circuit test system for an inverter according to any one of claims 1-3, characterized in that, The first circuit breaker includes at least one sub-circuit breaker, which is provided in a one-to-one correspondence with the phase lines included in the power grid.
5. The short-circuit test system for an inverter according to claim 4, characterized in that, The at least one sub-circuit breaker includes: The first sub-circuit breaker is installed on phase A of the power grid; The second sub-circuit breaker is installed on the B phase line of the power grid; The third sub-circuit breaker is installed on the C-phase line of the power grid.
6. The short-circuit test system for an inverter according to any one of claims 1-3, characterized in that, The second circuit breaker includes: The fourth sub-circuit breaker is connected to the neutral line of the power grid; The fifth sub-circuit breaker is connected to the ground wire of the power grid; The fourth sub-circuit breaker and the fifth sub-circuit breaker are respectively connected to the second output terminal of the second contactor.
7. The short-circuit test system for an inverter according to any one of claims 1-3, characterized in that, The second contactor includes at least one main contact, which is provided in a one-to-one correspondence with the phase lines included in the power grid.
8. The short-circuit test system for an inverter according to claim 7, characterized in that, The at least one main contact includes: The fourth main contact is located on phase A of the power grid; The fifth main contact is located on the B-phase line of the power grid; The sixth main contact is located on the C-phase line of the power grid.
9. The short-circuit test system for an inverter according to any one of claims 1-3, characterized in that, The circuit breaker is a remotely controlled circuit breaker.
10. The short-circuit test system for an inverter according to any one of claims 1-3, characterized in that, At least one of the first contactor, the circuit breaker, and the second contactor is a switching device.