Multi-break high voltage circuit breaker testing method and apparatus

Abstract

The application belongs to the technical field of electrical test, and provides a test method and device for a multi-break high-voltage circuit breaker, which comprises the following steps: applying an alternating voltage source to both ends of the multi-break high-voltage circuit breaker to form a test loop; controlling the multi-break high-voltage circuit breaker to perform a closing operation, and recording the current change in the test loop during the closing operation; and calculating the relevant parameters of the multi-break high-voltage circuit breaker according to the current change. The application can solve the problem that it is difficult to accurately test the parameters of the multi-break high-voltage circuit breaker with a closing resistor in the prior art.

Description

Technical Field

[0001] This invention belongs to the field of electrical testing technology, and in particular relates to a testing method and apparatus for multi-break high-voltage circuit breakers. Background Technology

[0002] High-voltage circuit breakers play a crucial role in the control and protection of high-voltage circuits in power systems, and are one of the most important pieces of equipment in these systems. Double-break high-voltage circuit breakers are a type of high-voltage circuit breaker that features two sets of breaks, resulting in stronger arc-extinguishing capabilities, making them more suitable for high-voltage power systems of 500kV and above.

[0003] Testing high-voltage circuit breakers includes measuring the closing resistance's engagement time and resistance value. Most existing technologies use a DC voltage source applied across the circuit breaker for measurement, but this method is only suitable for single-break closing resistance circuit breakers. This is because in double-break circuit breakers, the closing resistance contacts close preferentially. Due to the closing speed, there is some bounce after closure, electrically manifesting as alternating on and off states. This causes the two sets of contacts in the series circuit to conduct alternately, and as the voltage level increases, the bounce becomes more severe, and the contact time of the resistance contacts becomes shorter. Only when both sets of contacts close simultaneously can a circuit be formed, and the closing resistance value can be effectively measured. Furthermore, when the two sets of contacts are out of sync (asynchronous conduction), the conduction time of the first contact cannot be accurately measured, thus the engagement time cannot be accurately measured. Summary of the Invention

[0004] In view of this, embodiments of the present invention provide a testing method and apparatus for multi-break high-voltage circuit breakers to solve the problem in the prior art of accurately testing the parameters of multi-break high-voltage circuit breakers.

[0005] The first aspect of the present invention provides a test method for a multi-break high-voltage circuit breaker. The multi-break high-voltage circuit breaker is composed of at least two sets of breaks connected in series. Each set of breaks includes a voltage equalizing capacitor, a closing resistor, a resistance break, and a main break. The closing resistor and the resistance break are connected in series to form a closing resistor branch. The voltage equalizing capacitor, the closing resistor branch, and the main break are connected in parallel.

[0006] The method includes:

[0007] An AC voltage source is applied to both ends of a multi-break high-voltage circuit breaker to form a test circuit;

[0008] Control the multi-break high-voltage circuit breaker to perform the closing action, and record the current change in the test circuit during the closing action;

[0009] Calculate the relevant parameters of a multi-break high-voltage circuit breaker based on current changes.

[0010] In conjunction with the first aspect, in one possible implementation of the first aspect, the relevant parameters of the multi-break high-voltage circuit breaker are calculated based on current changes, including:

[0011] The moment when the first resistance break closes is determined based on the change in current, and is recorded as the first moment.

[0012] The moment when all main breaks close is determined based on the current change and is recorded as the second moment.

[0013] Based on the first and second time points, calculate the activation time of the closing resistor of the multi-break high-voltage circuit breaker.

[0014] In conjunction with the first aspect, in one possible implementation of the first aspect, the relevant parameters of the multi-break high-voltage circuit breaker are calculated based on current changes, including:

[0015] The current value in the test circuit of the target stage is determined based on the current change; among them, the closing operation process of the multi-break high-voltage circuit breaker is divided into multiple stages according to the state of the resistance break and the main break, and the target stage is any stage in which the resistance break is closed.

[0016] Calculate the resistance value of the closing resistor based on the frequency of the AC voltage source and the current value at the target stage.

[0017] In conjunction with the first aspect, in one possible implementation of the first aspect, the multi-break high-voltage circuit breaker is composed of two sets of breaks connected in series, and the target stage is the stage where only one resistance break is closed and all main breaks are open.

[0018] The formula for calculating the closing resistor value is as follows:

[0019] Where Ux is the voltage of the AC voltage source, Ix is the current value of the target stage, f is the frequency of the AC voltage source, C is the capacitance of the equalizing capacitor, and R is the resistance of the closing resistor.

[0020] In conjunction with the first aspect, in one possible implementation of the first aspect, the multi-break high-voltage circuit breaker is composed of two sets of breaks connected in series, and the target stage is the stage in which both resistance breaks are closed.

[0021] The formula for calculating the closing resistor value is as follows:

[0022] Where Ux is the voltage of the AC voltage source, Ix is the current value of the target stage, f is the frequency of the AC voltage source, C is the capacitance of the equalizing capacitor, and R is the resistance of the closing resistor.

[0023] In conjunction with the first aspect, in one possible implementation of the first aspect, the multi-break high-voltage circuit breaker is composed of two sets of breaks connected in series, and the target stage is the stage where one resistive break is closed and one main break is closed at the same time.

[0024] The formula for calculating the closing resistor value is as follows:

[0025] Where Ux is the voltage of the AC voltage source, Ix is the current value of the target stage, f is the frequency of the AC voltage source, C is the capacitance of the equalizing capacitor, and R is the resistance of the closing resistor.

[0026] In conjunction with the first aspect, in one possible implementation of the first aspect, the capacitance value of the equalizing capacitor in the high-voltage circuit breaker is calculated based on the current change;

[0027] The process of calculating the capacitance value of the voltage equalizing capacitor based on the change in current is as follows:

[0028] Based on the current change, determine the current value in the test circuit when each resistor break and the main break are not closed;

[0029] according to Calculate the capacitance value of the voltage equalization capacitor;

[0030] Where Ux is the voltage of the AC voltage source, Ix is the current value during the stage when each resistor break and the main break are not closed, f is the frequency of the AC voltage source, C is the capacitance value of the equalizing capacitor, and 2 indicates the series connection of the two sets of capacitors.

[0031] A second aspect of the present invention provides a testing device for multi-break high-voltage circuit breakers, comprising:

[0032] AC voltage source and test unit;

[0033] An AC voltage source is used to apply voltage across the two ends of a multi-break high-voltage circuit breaker to form a test circuit.

[0034] The test unit is used to record the current changes in the test circuit during the closing operation of a multi-break high-voltage circuit breaker, and to calculate the relevant parameters of the multi-break high-voltage circuit breaker based on the current changes.

[0035] In conjunction with the second aspect, in one possible implementation of the second aspect, the test unit is specifically used for:

[0036] The moment when the first resistance break closes is determined based on the change in current, and is recorded as the first moment.

[0037] The moment when all main breaks close is determined based on the current change and is recorded as the second moment.

[0038] Based on the first and second time points, calculate the activation time of the closing resistor of the multi-break high-voltage circuit breaker.

[0039] In conjunction with the second aspect, in one possible implementation of the second aspect, the test unit is specifically used for:

[0040] The current value in the test circuit of the target stage is determined based on the current change; among them, the closing operation process of the multi-break high-voltage circuit breaker is divided into multiple stages according to the state of the resistance break and the main break, and the target stage is any stage in which the resistance break is closed.

[0041] Calculate the resistance value of the closing resistor based on the frequency of the AC voltage source and the current value at the target stage.

[0042] The beneficial effects of the embodiments of the present invention compared with the prior art are as follows:

[0043] Multi-break high-voltage circuit breakers cannot have a measurement point led out from the middle, and the time during which each closing resistor conducts simultaneously is extremely short, full of uncertainty, making traditional DC testing methods ineffective. This invention cleverly utilizes the voltage-equalizing capacitors connected in parallel on the multi-break high-voltage circuit breaker to apply a regulated and current-limiting AC voltage source across the circuit breaker. Based on the current changes during the closing operation, the state of the resistor breaks and the main break can be analyzed, thereby deriving relevant parameters such as the closing resistor connection time and resistance value, achieving accurate testing of multi-break high-voltage circuit breakers, especially double-break high-voltage circuit breakers. Attached Figure Description

[0044] To more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0045] Figure 1 This is a schematic diagram of the testing principle of the multi-break high-voltage circuit breaker provided in an embodiment of the present invention;

[0046] Figure 2 This is a flowchart illustrating the testing method for multi-break high-voltage circuit breakers provided in this embodiment of the invention. Detailed Implementation

[0047] In the following description, specific details such as particular system architectures and techniques are set forth for illustrative purposes and not for limitation, in order to provide a thorough understanding of the embodiments of the invention. However, those skilled in the art will understand that the invention can be implemented in other embodiments without these specific details. In other instances, detailed descriptions of well-known systems, apparatuses, circuits, and methods are omitted so as not to obscure the description of the invention with unnecessary detail.

[0048] To illustrate the technical solution described in this invention, specific embodiments are described below.

[0049] In ultra-high voltage power grids of 500kV and above, in order to limit operational overvoltage, improve the breaking capacity of switchgear, and reduce interference such as line reclosing overvoltage, manufacturers of high-voltage circuit breakers install closing resistors in the circuit breakers. The closing resistors of circuit breakers can effectively limit the closing overvoltage of ultra-high voltage AC systems. For AC systems of 800kV and above, even for short lines with a line length of 100km or less, it is difficult to limit the closing overvoltage within the range specified in the regulations without the use of closing resistors.

[0050] A double-break high-voltage circuit breaker is a type of high-voltage circuit breaker. It has two sets of breaks, resulting in stronger arc-extinguishing capability. For example... Figure 1 As shown, in a double-break high-voltage circuit breaker, two sets of breaks are connected in series, and R1 and R2 are the closing resistors in the two sets of breaks, respectively.

[0051] According to design standards, the closing resistor's engagement time and resistance value need to be measured for high-voltage circuit breakers. However, components such as the closing resistor and equalizing capacitor are generally sealed inside the high-voltage circuit breaker and can only be opened during major overhauls. Disassembly is not possible under normal circumstances, and without disassembly, direct contact with the two ends of the closing resistor is impossible. Furthermore, the intermediate connection point cannot be brought out for double-break high-voltage circuit breakers. Existing testing devices mostly use DC voltage sources for measurement, which are only suitable for single-break high-voltage circuit breakers. If a DC voltage source is applied to both ends of a double-break circuit breaker, effective measurement is only possible when both resistor breaks close simultaneously. With the increase in voltage levels and the need for arc extinguishing, the closing speed of the main break has also increased to some extent. This increased speed leads to a shorter contact time between the resistor breaks, and due to the inherent bounce of the resistor breaks, the timing of the simultaneous conduction of the two closing resistors is not fixed, making effective measurement impossible.

[0052] First, the multi-break high-voltage circuit breaker provided in the embodiments of the present invention will be introduced. The multi-break high-voltage circuit breaker is composed of at least two sets of breaks connected in series. Each set of breaks includes a voltage equalizing capacitor, a closing resistor, a resistor break and a main break. The closing resistor and the resistor break are connected in series to form a closing resistor branch. The voltage equalizing capacitor, the closing resistor branch and the main break are connected in parallel.

[0053] This embodiment uses a double-break high-voltage circuit breaker as an example, which consists of two sets of breaks connected in series. See the attached diagram for the structure. Figure 1 As shown. K1 and K2 are the main breaks of the two sets of breaks, respectively. K11 and K21 are the resistive breaks of the two sets of breaks, respectively. C1 and C2 are the voltage-equalizing capacitors of the two sets of breaks, respectively. Usually, the voltage-equalizing capacitors C1 and C2 are of equal value, and the resistors R1 and R2 are of equal resistance. V is the AC voltage source used for testing. M is the test unit.

[0054] This method is applicable to multi-break high-voltage circuit breakers, especially double-break high-voltage circuit breakers.

[0055] See Figure 2 As shown, the method includes:

[0056] Step S101: Apply an AC voltage source to both ends of the multi-break high-voltage circuit breaker to form a test circuit.

[0057] Step S102: Control the multi-break high-voltage circuit breaker to perform a closing action, and record the current change in the test circuit during the closing action.

[0058] Step S103: Calculate the relevant parameters of the multi-break high-voltage circuit breaker based on the current change.

[0059] In this embodiment, because the simultaneous conduction time of the two resistance breaks K11 and K21 is extremely short (<100μs) and full of uncertainties, traditional DC methods cannot effectively measure it. This embodiment utilizes parallel equalizing capacitors C1 and C2 to apply a regulated and current-limiting AC voltage source V to both sides of the double-break high-voltage circuit breaker. During the closing operation, each high-voltage circuit breaker first closes the resistance breaks (K11, K21), then opens the resistance breaks, and closes the main breaks (K1, K2).

[0060] Therefore, we can conclude that:

[0061] When K1, K2, K11, and K21 are all off, there is a current I1 passing through C1 and C2.

[0062] There is a current I2 when either K11 or K21 is turned on.

[0063] When K11 and K21 are both turned on, there is a current I3.

[0064] There is a current I4 when either K1 or K2 is turned on.

[0065] When K1 and K2 are both turned on, there is a current I5.

[0066] By measuring the changes in I1, I2, I3, I4, and I5 using the test unit M, the operating state of each switch can be determined, thereby determining the activation time of the closing resistor and calculating its resistance value.

[0067] It is evident that a measurement point cannot be led out from the middle of a multi-break high-voltage circuit breaker, and the simultaneous conduction time of each closing resistor is extremely short, filled with uncertainty, making traditional DC testing methods ineffective. This invention cleverly utilizes the voltage-equalizing capacitors connected in parallel on the multi-break high-voltage circuit breaker, applying a regulated and current-limiting AC voltage source to both sides of the circuit breaker. Based on the current changes during the closing operation, the state of the resistor breaks and the main break can be analyzed, thereby deriving relevant parameters such as the closing resistor connection time and resistance value, achieving accurate testing of multi-break high-voltage circuit breakers, especially double-break high-voltage circuit breakers.

[0068] As one possible implementation, step S103 calculates the relevant parameters of the multi-break high-voltage circuit breaker based on current changes, including:

[0069] The moment when the first resistance break closes is determined based on the change in current, and is recorded as the first moment.

[0070] The moment when all main breaks close is determined based on the current change and is recorded as the second moment.

[0071] Based on the first and second time points, calculate the activation time of the closing resistor of the multi-break high-voltage circuit breaker.

[0072] In this embodiment, the closing resistor engagement time is the time from the closure of the first resistor break to the engagement of all main breaks. For example, for a double-break high-voltage circuit breaker, the moment the first resistor break closes is the moment of change in current I2, and the moment all main breaks are engaged is the moment of change in current I5. Based on the overall current variation characteristics, each moment can be analyzed and determined. In this way, the problem of inaccurate measurement of the engagement time due to the asynchronous conduction of the two sets of resistor breaks (poor synchronization) is solved.

[0073] As one possible implementation, step S103 calculates the relevant parameters of the multi-break high-voltage circuit breaker based on current changes, including:

[0074] The current value in the test circuit of the target stage is determined based on the current change; among them, the closing operation process of the multi-break high-voltage circuit breaker is divided into multiple stages according to the state of the resistance break and the main break, and the target stage is any stage in which the resistance break is closed.

[0075] Calculate the resistance value of the closing resistor based on the frequency of the AC voltage source and the current value at the target stage.

[0076] In this embodiment, the resistance value of the closing resistor can be calculated using the stage where the closing resistor is connected. Figure 1 The double-break high-voltage circuit breaker shown is an example:

[0077] When either K11 or K21 is conducting, the equivalent impedance of the circuit is equal to the capacitive reactance of C1 plus the parallel connection of R2 and C2, which is...

[0078] Therefore, the resistance R can be passed through calculate.

[0079] Where Xc is the capacitive reactance, with the SI unit being ohms (Ω); f is the frequency of the alternating current, with the SI unit being hertz (Hz); C is the capacitance of the equalizing capacitor, with the SI unit being farads (F); the voltage Ux is a known quantity; and the value of Ix is the measured current I2.

[0080] Alternatively, when K11 and K21 are both on, the equivalent impedance of the circuit is

[0081]

[0082] Therefore, the resistance R can be passed through The value of Ix is calculated to be the measured current I3.

[0083] Alternatively, when either K1 or K2 is turned on, the equivalent impedance of the circuit is... Therefore, the resistance R can be passed through The value of Ix is calculated to be the measured current I4.

[0084] As one possible implementation, this embodiment can also simultaneously measure the capacitance value of the voltage equalization capacitor, the method being:

[0085] Based on the current change, determine the current value in the test circuit when each resistor break and the main break are not closed;

[0086] according to Calculate the capacitance value of the voltage equalization capacitor;

[0087] Where Ux is the voltage of the AC voltage source, Ix is the current value during the stage when each resistor break and the main break are not closed, f is the frequency of the AC voltage source, and C is the capacitance value of the equalizing capacitor.

[0088] In this embodiment, when K1, K2, K11, and K21 are all off, it is equivalent to two equalizing capacitors connected in series. Based on the capacitive reactance in the circuit... The capacitance value C can be calculated accurately, the voltage Ux is a known quantity, and the value of Ix is the current I1. This method can further ensure the accuracy of the capacitance value of the voltage equalizing capacitor.

[0089] It should be understood that the sequence number of each step in the above embodiments does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present invention.

[0090] This invention provides a testing device for multi-break high-voltage circuit breakers, including as follows: Figure 1 The AC voltage source V and the test unit M are shown.

[0091] An AC voltage source V is applied across the two ends of a multi-break high-voltage circuit breaker to form a test circuit.

[0092] Test unit M is used to record the current changes in the test circuit during the closing operation of a multi-break high-voltage circuit breaker, and to calculate relevant parameters of the multi-break high-voltage circuit breaker based on the current changes. Test unit M integrates sampling and a DSP processor, which can effectively record the current waveform during the closing process.

[0093] As one possible implementation, the test unit M is specifically used for:

[0094] The moment when the first resistance break closes is determined based on the change in current, and is recorded as the first moment.

[0095] The moment when all main breaks close is determined based on the current change and is recorded as the second moment.

[0096] Based on the first and second time points, calculate the activation time of the closing resistor of the multi-break high-voltage circuit breaker.

[0097] As one possible implementation, the test unit M is specifically used for:

[0098] The current value in the test circuit of the target stage is determined based on the current change; among them, the closing operation process of the multi-break high-voltage circuit breaker is divided into multiple stages according to the state of the resistance break and the main break, and the target stage is any stage in which the resistance break is closed.

[0099] Calculate the resistance value of the closing resistor based on the frequency of the AC voltage source and the current value at the target stage.

[0100] As one possible implementation, a multi-break high-voltage circuit breaker consists of two sets of breaks connected in series, with the target stage being when only one resistance break is closed and all main breaks are open.

[0101] The formula for calculating the closing resistor value is as follows:

[0102] Where Ux is the voltage of the AC voltage source, Ix is the current value of the target stage, f is the frequency of the AC voltage source, C is the capacitance of the equalizing capacitor, and R is the resistance of the closing resistor.

[0103] As one possible implementation, a multi-break high-voltage circuit breaker consists of two sets of breaks connected in series, with the target stage being the stage where both resistance breaks are closed.

[0104] The formula for calculating the closing resistor value is as follows:

[0105] Where Ux is the voltage of the AC voltage source, Ix is the current value of the target stage, f is the frequency of the AC voltage source, C is the capacitance of the equalizing capacitor, and R is the resistance of the closing resistor.

[0106] As one possible implementation, a multi-break high-voltage circuit breaker consists of two sets of breaks connected in series, with the target stage being the closure of one resistance break and the closure of one main break.

[0107] The formula for calculating the closing resistor value is as follows:

[0108] Where Ux is the voltage of the AC voltage source, Ix is the current value of the target stage, f is the frequency of the AC voltage source, C is the capacitance of the equalizing capacitor, and R is the resistance of the closing resistor.

[0109] As one possible implementation, the capacitance value of the equalizing capacitor is calculated based on the change in current.

[0110] The process of calculating the capacitance value of the voltage equalizing capacitor based on the change in current is as follows:

[0111] Based on the current change, determine the current value in the test circuit when each resistor break and the main break are not closed;

[0112] according to Calculate the capacitance value of the voltage equalization capacitor;

[0113] Where Ux is the voltage of the AC voltage source, Ix is the current value during the stage when each resistor break and the main break are not closed, f is the frequency of the AC voltage source, and C is the capacitance value of the equalizing capacitor.

[0114] The above-described embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be included within the protection scope of the present invention.

Claims

1. A test method for a multi-break high-voltage circuit breaker, characterized in that, The multi-break high-voltage circuit breaker is composed of at least two groups of breaks in series, each group of breaks including a voltage equalization capacitor, a closing resistor, a resistor break, and a main break, the closing resistor and the resistor break being connected in series to form a closing resistor branch, and the voltage equalization capacitor, the closing resistor branch, and the main break being connected in parallel; The method comprises: applying an alternating voltage source to both ends of the multi-break high-voltage circuit breaker to form a test loop; controlling the multi-break high-voltage circuit breaker to perform a closing operation and recording current changes in the test loop during the closing operation; calculating relevant parameters of the multi-break high-voltage circuit breaker according to the current changes; The calculation of the relevant parameters of the multi-break high-voltage circuit breaker according to the current changes comprises: determining the time when the first resistor break is closed according to the current changes, denoted as a first time; determining the time when all the main breaks are closed according to the current changes, denoted as a second time; calculating the closing resistor input time of the multi-break high-voltage circuit breaker based on the first time and the second time; The calculation of the relevant parameters of the multi-break high-voltage circuit breaker according to the current changes comprises: determining the current value in the test loop at a target stage according to the current changes; wherein the closing operation of the multi-break high-voltage circuit breaker is divided into multiple stages according to the states of the resistor breaks and the main breaks, and the target stage is any stage in which a resistor break is closed; calculating the resistance value of the closing resistor based on the frequency of the alternating voltage source and the current value at the target stage.

2. The method of claim 1, wherein the plurality of breaks are formed by a plurality of breakers. The multi-break high-voltage circuit breaker is composed of two groups of breaks in series, and the target stage is a stage in which only one resistor break is closed and all the main breaks are disconnected; The formula for calculating the resistance value of the closing resistor is ; wherein, is the voltage of the AC voltage source, is the current value of the target phase, is the frequency of the AC voltage source, is the capacitance value of the voltage equalization capacitor, is the resistance value of the closing resistor.

3. The method of claim 1, wherein the plurality of breaks are generated by a plurality of breakers. The multi-break high-voltage circuit breaker is composed of two groups of breaks in series, and the target stage is a stage in which both resistor breaks are closed; The formula for calculating the resistance value of the closing resistor is ; wherein, is the voltage of the AC voltage source, is the current value of the target phase, is the frequency of the AC voltage source, is the capacitance value of the voltage equalization capacitor, is the resistance value of the closing resistor.

4. The method of claim 1, wherein the plurality of breaks are generated by a plurality of breakers. The multi-break high-voltage circuit breaker is composed of two groups of breaks in series, and the target stage is a stage in which one resistor break is closed and one main break is closed; The formula for calculating the resistance value of the closing resistor is ; wherein, is the voltage of the AC voltage source, is the current value of the target phase, is the frequency of the AC voltage source, is the capacitance value of the voltage equalization capacitor, is the resistance value of the closing resistor.

5. The method of testing a multi-break high voltage circuit breaker of any of claims 2-4, wherein, The capacitance value of the voltage equalization capacitor is calculated according to the current changes; The process of calculating the capacitance value of the voltage equalization capacitor according to the current changes comprises: determining the current value in the test loop at a stage in which none of the resistor breaks and the main breaks is closed according to the current changes; According to a value of the equalizing capacitor is calculated; wherein, is the voltage of the alternating voltage source, is the current value in the stage in which the individual resistance breaks and the main break are not closed, is the frequency of the alternating voltage source, is the capacitance value of the voltage equalization capacitor.

6. A multi-break high voltage circuit breaker testing device, characterized by, The process comprises: an alternating voltage source and a test unit; The alternating voltage source is used to be applied to both ends of the multi-break high-voltage circuit breaker to form a test loop; The test unit is used to record current changes in the test loop during the closing operation of the multi-break high-voltage circuit breaker and to calculate relevant parameters of the multi-break high-voltage circuit breaker according to the current changes; The test unit is specifically used to: determine the time when the first resistor break is closed according to the current changes, denoted as a first time; determine the time when all the main breaks are closed according to the current changes, denoted as a second time; calculate the closing resistor input time of the multi-break high-voltage circuit breaker based on the first time and the second time; The test unit is specifically used to: determine the current value in the test loop at a target stage according to the current changes; wherein the closing operation of the multi-break high-voltage circuit breaker is divided into multiple stages according to the states of the resistor breaks and the main breaks, and the target stage is any stage in which a resistor break is closed; calculate the resistance value of the closing resistor based on the frequency of the alternating voltage source and the current value at the target stage.

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