A method and device for testing the characteristics of a load switch with a transfer open branch

Abstract

The present application relates to the technical field of performance inspection of load switch, in particular to a load switch characteristic test method and device with a transfer opening branch, first connecting a test circuit with a measured load switch; the signal end of the three groups of probes of an oscilloscope is connected with the first voltage collection point, the second voltage collection point and the third voltage collection point respectively, and the ground wire of the oscilloscope is connected with the fourth voltage collection point; the measured load switch is operated to open, and the voltage signal of the signal end in different time periods is collected to obtain the level change time sequence diagram of different voltage collection points, and the change of the current flowing through the arc extinguishing chamber in the opening process can be accurately obtained, which provides a basis for the design of the arc extinguishing chamber.

Description

Technical Field

[0001] This invention relates to the field of performance testing technology for load switches, and specifically to a method and apparatus for testing the characteristics of a load switch with a transfer switching branch. Background Technology

[0002] High-voltage load switches are key devices in power systems, functioning between high-voltage circuit breakers and high-voltage disconnectors. They are primarily used to control power transformers and distribute electrical energy. High-voltage load switch characteristic testing is crucial for ensuring the safe operation of power equipment, involving parameters such as mechanical characteristics, electrical performance, and environmental adaptability. Current high-voltage switch characteristic testers can only detect the high and low level signals (0 and 1) of the circuit under test to characterize two parameters: bounce and synchronicity during opening and closing. For example, the utility model patent with authorization announcement number CN214150964U discloses a high-voltage switch dynamic characteristic tester with stable measurement data. This instrument converts the analog signals of the high-voltage switch's opening and closing coils into current signals via Hall effect sensors. The current signal is then converted into a voltage signal by measuring resistor R6, amplified by an in-phase amplifier, and finally sent to the built-in A / D converter of the S3C2410 microprocessor for analog-to-digital conversion, completing the acquisition of the high-voltage switch's opening and closing coil currents. The microprocessor only determines the circuit breaker's state by detecting the high and low levels of the voltage level.

[0003] Furthermore, existing technologies can only display the overall bounce and synchronicity of the switch under test when encountering switches with transfer disconnection branches, and cannot accurately analyze and locate abnormalities in the opening and closing process.

[0004] The invention patent with publication number CN116593881A discloses a three-phase high-voltage contact resistance and switch characteristic testing device and method. When the data acquisition unit control interface drive unit drives the first interface unit and the second interface unit to conduct, the closed voltage of the three phases of the three-phase high-voltage switch is measured respectively. When the data acquisition unit control interface drive unit drives the third interface unit, the fourth interface unit and the fifth interface unit to conduct, the closed current of the three phases of the three-phase high-voltage switch is measured respectively. The waveform measurement unit is implemented by a voltage divider circuit, an A-phase operational amplifier circuit and an operational amplifier circuit. The voltage divider circuit includes two resistors and the amplifier circuit includes an amplifier and a resistor. It only detects the synchronicity of the high-voltage switch opening by the voltage timing waveform diagram of each phase. Summary of the Invention

[0005] Objective of the Invention: To overcome the shortcomings of the prior art, this invention proposes a method for testing the characteristics of a load switch with a transfer breaking branch. This method solves the problems of inaccurate and insufficiently intuitive judgment of abnormal situations during the actual tripping process of high-load switches. This invention also proposes a device for testing the characteristics of a load switch with a transfer breaking branch.

[0006] Summary of the Invention: This invention provides a method for testing the characteristics of a load switch with a transfer interruption branch, the method comprising:

[0007] The first voltage acquisition point in the test circuit is connected to the moving contact of the load switch under test. The second voltage acquisition point in the test circuit is connected to the arc-extinguishing chamber of the load switch under test that is away from the stationary contact. The third voltage acquisition point in the test circuit is connected to the stationary contact of the load switch under test. The fourth voltage acquisition point in the test circuit is connected to the arc-extinguishing chamber of the load switch under test that is close to the stationary contact.

[0008] The signal terminals of the three probes of the oscilloscope are connected to the first voltage acquisition point, the second voltage acquisition point, and the third voltage acquisition point, respectively, and the ground wire of the oscilloscope is connected to the fourth voltage acquisition point;

[0009] The tested load switch is tripped, and the voltage signal at the signal terminal is collected at different time periods to obtain a time sequence diagram of level change at different voltage acquisition points. The time sequence diagram of level change is compared and analyzed with the corresponding theoretical time sequence diagram to determine the mutual influence between different acquisition points.

[0010] Furthermore, the method also includes:

[0011] A displacement sensor is fixed between the moving contact shaft of the load switch under test and the arc-extinguishing chamber to obtain a displacement curve of the moving contact and the contact inside the arc-extinguishing chamber relative to time during the opening process. By combining the different time periods in the theoretical time sequence diagram of the level change with the time axis of the displacement curve, a displacement time sequence diagram is obtained, thereby analyzing the abnormal situation of the travel of the moving contact and the arc-extinguishing chamber in each time period.

[0012] Furthermore, including:

[0013] The test circuit includes seven voltage-regulating resistors with the same resistance value. The first resistor R1 and the second resistor R2 are connected in series to form the second acquisition unit. The third resistor R3 and the fourth resistor R4 are connected in series to form the first acquisition unit. The fifth resistor R5 and the sixth resistor R6 are connected in series to form the third acquisition unit. The seventh resistor R7 is connected in parallel with the sixth resistor R6. The two ends of the first acquisition unit, the second acquisition unit and the third acquisition unit are respectively connected to the positive and negative terminals of the power module.

[0014] Furthermore, including:

[0015] The first voltage acquisition point is set between the third resistor R3 and the fourth resistor R4 in the first acquisition unit; the second voltage acquisition point is set between the first resistor R1 and the second resistor R2 in the second acquisition unit; the third voltage acquisition point is set between the fifth resistor R5 and the sixth resistor R6 in the third acquisition unit; and the fourth voltage acquisition point is set at the connection point of the sixth resistor R6 and the seventh resistor R7.

[0016] Furthermore, including:

[0017] The process of tripping the tested load switch and collecting voltage signals from the signal terminal at different time periods to obtain a time-series diagram of voltage level changes at different sampling points includes:

[0018] Seven time points were determined during the tripping process of the tested load switch: t0, the time when the isolating switch of the tested load switch began to trip and the moving contact and stationary contact began to separate; t1, the time when the current began to transfer to the arc-extinguishing chamber; t2, the time when the moving contact and stationary contact completed separation; t3, the time when the contacts inside the arc-extinguishing chamber completed separation; t4, the time when the trip unit of the arc-extinguishing device completed separation from the stationary contact; t5, the time when the contacts inside the arc-extinguishing chamber completed closing due to the self-closing force of the arc-extinguishing chamber; and t6, the time when the tested load switch was re-closed.

[0019] The level changes considered at different voltage acquisition points include the level changes between the first and fourth voltage acquisition points, the level changes between the second and fourth voltage acquisition points, the level changes between the first and third voltage acquisition points, and the level changes between the fourth and third voltage acquisition points.

[0020] Therefore, the timing diagrams of the above four level changes in different time periods were obtained respectively.

[0021] Furthermore, including:

[0022] The process of obtaining the timing diagrams of the above four levels of change at different time periods includes:

[0023] The values ​​at the seven time points are determined based on the test circuit. The level changes at different voltage acquisition points are expressed as a percentage relative to the power supply voltage, thereby obtaining the voltage values ​​between two different voltage acquisition points in different time periods. The voltage values ​​include the power supply voltage V0, zero, 2 / 3 V0, and 1 / 2 V0. The mutual influence between the four circuits is obtained based on the voltage values ​​between two different voltage acquisition points.

[0024] Furthermore, including:

[0025] The resistance value of the voltage regulating resistor is set according to the power supply voltage value of the power supply module.

[0026] On the other hand, the present invention also provides a load switch characteristic testing device with a transfer breaking branch. The device includes a load switch under test, an oscilloscope, a test circuit, and a power supply module. The load switch under test includes a bracket, with a first supporting insulator and a second supporting insulator respectively installed at both ends of the bracket. The first supporting insulator is provided with a terminal, which is connected to the rear end of the moving contact blade. The second supporting insulator is equipped with a stationary contact. An arc-extinguishing chamber is located between the two blades of the moving contact blade. The rear end of the arc-extinguishing chamber is hinged to the moving contact blade. The contact piece at the front end of the arc-extinguishing chamber is inserted into the slot of the stationary contact. The front end of the moving contact blade is away from or close to the stationary contact. The positive and negative terminals of the test circuit are connected to the power supply module. The voltage acquisition point of the test circuit is connected to the relevant position of the load switch under test. The oscilloscope is connected to the voltage acquisition point to display the voltage signal at the current voltage acquisition point, thereby obtaining a timing diagram of level changes.

[0027] Furthermore, including:

[0028] The device also includes a displacement sensor, which is disposed between the moving contact blade shaft of the load switch under test and the arc-extinguishing chamber.

[0029] Furthermore, including:

[0030] The first voltage acquisition point in the test circuit is connected to the moving contact of the load switch under test. The second voltage acquisition point in the test circuit is connected to the arc-extinguishing chamber end of the load switch under test that is furthest from the stationary contact. The third voltage acquisition point in the test circuit is connected to the stationary contact of the load switch under test. The fourth voltage acquisition point in the test circuit is connected to the arc-extinguishing chamber end of the load switch under test that is closest to the stationary contact.

[0031] Furthermore, including:

[0032] The test circuit includes seven voltage-regulating resistors with the same resistance value. The first resistor R1 and the second resistor R2 are connected in series to form the second acquisition unit. The third resistor R3 and the fourth resistor R4 are connected in series to form the first acquisition unit. The fifth resistor R5 and the sixth resistor R6 are connected in series to form the third acquisition unit. The seventh resistor R7 is connected in parallel with the sixth resistor R6. The two ends of the first acquisition unit, the second acquisition unit and the third acquisition unit are respectively connected to the positive and negative terminals of the power module.

[0033] Beneficial effects: Compared with the prior art, the present invention has the following advantages:

[0034] (1) Based on the proposed test circuit, this invention combines it with an oscilloscope to specifically address the shortcomings of the prior art. It can intuitively display the opening and closing bounce and synchronicity of one circuit consisting of a moving blade and a stationary contact, and the opening and closing bounce and synchronicity of another circuit consisting of an arc-extinguishing chamber and a transfer breaking branch. Furthermore, the data obtained from the two circuits are output on the same page, which makes it convenient for R&D personnel to directly locate abnormal points through the obtained waveform diagram.

[0035] (2) The test circuit proposed in this invention only requires a few voltage-regulating resistors connected in series and parallel. The resistance value is adjusted according to the power supply voltage value. Several acquisition points are selected on the test circuit and connected to the relevant positions of the high-voltage load switch to acquire voltage signals at different positions and time intervals, thereby forming waveform diagrams of level changes at different positions in different time intervals. After corresponding with the theoretical waveform diagram, the location of the abnormality can be clearly known. The implementation scheme is simple and highly executable.

[0036] (3) The present invention combines the stroke curve of the moving contact knife and the arc-extinguishing chamber with the actual timing diagram, which can more accurately judge the abnormal situation in the actual opening process, thereby accurately obtaining the change of current flowing through the arc-extinguishing chamber during the opening process, and providing a basis for the design of the arc-extinguishing chamber. Attached Figure Description

[0037] Figure 1 This is a flowchart of the load switch characteristic test method with transfer interruption branch as described in Embodiment 1 of the present invention;

[0038] Figure 2 This is a structural diagram of the test circuit described in Embodiment 1 of the present invention;

[0039] Figure 3 This is the timing diagram of the operation obtained from the circuit breaker tripping process described in Embodiment 1 of the present invention;

[0040] Figure 4 As described in Embodiment 1 of the present invention Figure 3 The theoretical timing diagram obtained under the same conditions of the action timing diagrams in the process;

[0041] Figure 5 This is a flowchart of the load switch characteristic test method with transfer disconnection branch according to an embodiment of the present invention;

[0042] Figure 6 This is a time-displacement curve obtained from the circuit breaker tripping process described in Embodiment 2 of the present invention;

[0043] Figure 7 This is a displacement timing diagram obtained from the circuit breaker tripping process described in Embodiment 2 of the present invention;

[0044] Figure 8This is a schematic diagram of the structure of the high-load switch in the closed state according to Embodiment 3 of the present invention;

[0045] Figure 9 This is a schematic diagram showing the connection between the high-load switch tripping state and the circuit under test as described in Embodiment 3 of the present invention;

[0046] Figure 10 This is a displacement timing diagram under a certain abnormal condition as described in Embodiment 3 of the present invention;

[0047] The figure includes: 1. Supporting insulator; 2. Bracket; 3. Moving contact blade; 4. Stationary contact; 5. Vacuum interrupter; 6. Tension spring; 7. Contact piece; 8. Slot; 9. Stop block; 10. Irregular spring. Detailed Implementation

[0048] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Example

[0049] like Figure 1 As shown, the present invention provides a method for testing the characteristics of a load switch with a transfer interruption branch, the method comprising the following steps:

[0050] S1 connects the first voltage acquisition point in the test circuit to the moving contact of the load switch under test, the second voltage acquisition point in the test circuit is connected to the arc-extinguishing chamber end of the load switch under test that is away from the stationary contact, the third voltage acquisition point in the test circuit is connected to the stationary contact of the load switch under test, and the fourth voltage acquisition point in the test circuit is connected to the arc-extinguishing chamber end of the load switch under test that is close to the stationary contact.

[0051] In this embodiment, as Figure 2 As shown, the test circuit includes seven voltage-regulating resistors with the same resistance value. The first resistor R1 and the second resistor R2 are connected in series to form the second acquisition unit. The third resistor R3 and the fourth resistor R4 are connected in series to form the first acquisition unit. The fifth resistor R5 and the sixth resistor R6 are connected in series to form the third acquisition unit. The seventh resistor R7 is connected in parallel with the sixth resistor R6. The first acquisition unit, the second acquisition unit and the third acquisition unit are connected to the positive and negative terminals of the power module, respectively.

[0052] The first voltage acquisition point is set between the third resistor R3 and the fourth resistor R4 in the first acquisition unit; the second voltage acquisition point is set between the first resistor R1 and the second resistor R2 in the second acquisition unit; the third voltage acquisition point is set between the fifth resistor R5 and the sixth resistor R6 in the third acquisition unit; and the fourth voltage acquisition point is set at the connection point of the sixth resistor R6 and the seventh resistor R7.

[0053] Specifically, in a preferred embodiment of this invention, during practical application, a test circuit and the load switch under test are prepared. The "+" point in the test circuit schematic is connected to the positive terminal of the power supply, and the "-" point is connected to the negative terminal of the power supply. The power supply voltage is V0. The first voltage acquisition point A1 is connected to the moving contact of the load switch under test. The second voltage acquisition point A3 is connected to the end of the arc-extinguishing chamber away from the stationary contact. The third voltage acquisition point a is connected to the stationary contact. The fourth voltage acquisition point A2 is connected to the end of the arc-extinguishing chamber near the stationary contact. After the test circuit and the load switch under test are connected, the power is turned on. The signal terminals of the three sets of probes of the oscilloscope are connected to the corresponding first voltage acquisition point A1, second voltage acquisition point A3, and third voltage acquisition point a, respectively. The ground wires are all connected to the fourth voltage acquisition point A2. The load switch is operated to perform a tripping operation. The voltage signals of the three sets of probes of the oscilloscope are acquired during the tripping operation to obtain three sets of voltage waveform diagrams.

[0054] Preferably, in this embodiment, the resistance value of the voltage regulating resistor is set according to the power supply voltage value of the power supply module. The table below provides several recommended values ​​for the power supply voltage V0 and the voltage regulating resistor R.

[0055]

[0056] The signal terminals of the three probes of the S2 oscilloscope are connected to the first, second, and third voltage acquisition points, respectively, and the ground wire of the oscilloscope is connected to the fourth voltage acquisition point. This embodiment does not limit the specific model of the oscilloscope.

[0057] S3 performs a tripping operation on the load switch under test and collects the voltage signal at the signal terminal at different time periods to obtain a time sequence diagram of level change at different voltage acquisition points; the time sequence diagram of level change is compared with the corresponding theoretical time sequence diagram to obtain the mutual influence between different acquisition points.

[0058] Preferably, in this embodiment, the tested load switch is tripped, and the voltage signal at the signal terminal is collected at different time periods to obtain a time sequence diagram of the level change at different voltage acquisition points, including:

[0059] First, determine seven time points during the tripping process of the load switch under test: t0, the time when the isolating switch of the load switch under test begins to trip and the moving contact begins to separate from the stationary contact; t1, the time when the current begins to transfer to the arc-extinguishing chamber; t2, the time when the moving contact and the stationary contact complete separation; t3, the time when the contacts inside the arc-extinguishing chamber complete separation; t4, the time when the trip unit of the arc-extinguishing device completes separation from the stationary contact; t5, the time when the contacts inside the arc-extinguishing chamber complete closing due to the self-closing force of the arc-extinguishing chamber; and t6, the time when the load switch under test recloses.

[0060] Secondly, the level changes considered at different voltage acquisition points include the level changes between the first and fourth voltage acquisition points, the level changes between the second and fourth voltage acquisition points, the level changes between the first and third voltage acquisition points, and the level changes between the fourth and third voltage acquisition points.

[0061] Therefore, the timing diagrams of the above four level changes in different time periods were obtained respectively.

[0062] In this embodiment, the values ​​of the seven time points are determined according to the test circuit. The level change at different voltage acquisition points is expressed as a percentage relative to the power supply voltage, thereby obtaining the voltage value between two different voltage acquisition points in different time periods. The voltage value includes the power supply voltage V0, zero, 2 / 3 V0, and 1 / 2 V0. The mutual influence between the four circuits is obtained based on the voltage value between two different voltage acquisition points.

[0063] Specifically, such as Figure 3 As shown, in the left column, "A1-A2" represents the level change between points A1 and A2, where A1 is the positive terminal of the oscilloscope signal acquisition probe and A2 is the negative terminal; "A3-A2" represents the level change between points A3 and A2, where A3 is the positive terminal of the oscilloscope signal acquisition probe and A2 is the negative terminal; "A1-a" represents the level change between points A1 and a, where A1 is the positive terminal of the oscilloscope signal acquisition probe and a is the negative terminal; "A2-a" represents the level change between points A2 and a, where A2 is the positive terminal of the oscilloscope signal acquisition probe and a is the negative terminal. This diagram illustrates the continuity of the loops between any two points in the four signal acquisition points A1, A2, A3, and a, such as the four loops A1-A2, A3-A2, A1-a, and A2-a. The circuit only has two signal levels, high and low. Each circuit has an independent and unrelated effect, making it impossible to observe the mutual influence between the three signal acquisition points simultaneously.

[0064] like Figure 4As shown, in the left column, "A1-A2" represents the level change between points A1 and A2, where A1 is the positive terminal of the oscilloscope signal acquisition probe and A2 is the negative terminal of the oscilloscope signal acquisition probe; "A3-A2" represents the level change between points A3 and A2, where A3 is the positive terminal of the oscilloscope signal acquisition probe and A2 is the negative terminal of the oscilloscope signal acquisition probe; "a-A2" represents the level change between points a and A2, where a is the positive terminal of the oscilloscope signal acquisition probe and A2 is the negative terminal of the oscilloscope signal acquisition probe.

[0065] Figure 3 and Figure 4 The time points corresponding to the horizontal axis in the figure have the same meaning, and are explained as follows: t0: The isolating switch begins to open, and the moving contact and stationary contact begin to separate; t1: Current begins to transfer to the arc-extinguishing chamber; t2: The moving contact and stationary contact complete separation; t3: The contacts inside the arc-extinguishing chamber complete separation; t4: The trip unit of the arc-extinguishing device completes separation from the stationary contact; t5: The contacts inside the arc-extinguishing chamber complete closure due to the self-closing force of the arc-extinguishing chamber; t6: The load switch closes again.

[0066] Figure 4 This is the theoretical timing diagram of the test circuit. Because the test circuit proposed in this embodiment is used, the signals of the four loops A1-A2, A3-A2, A1-a, and A2-a between the four signal points are changed from high and low level signals to voltage signals relative to the input power supply voltage value. For example, if the input power supply voltage value is V0 volts, four different voltage signals can be observed: 0 volts, two-thirds of V0 volts, half of V0 volts, and V0 volts. By distinguishing these different voltage values, the mutual influence between the four loops during the circuit breaker tripping process can be displayed, such as:

[0067] The loop voltage value between A1 and A2 at time t2, if there is no test circuit, such as Figure 3 At time point t2 and after time point t2, the voltage values ​​collected in the A1-A2 loop should be the same as those collected during the t0-t1 time period. After connecting to the test circuit, if... Figure 4 During the time period t0-t1, V0 is two-thirds of the time, while at and after time t2, this value becomes V0. Due to the inclusion of the test circuit proposed in this invention, the mutual influence between the four types of loops is increased. At this point, the mutual influence between loops A1-A2 and a-A2 is introduced: During the time period t0-t1, both loops a-A2 and A1-A2 are in the ON state; at time t2, loop a-A2 is in the OFF state, and loop A1-A2 changes from the OFF state to the ON state. For ease of understanding, the following table is provided:

[0068] With the advent of the test circuit, the voltage signals between circuits have been expanded from only two levels, high and low, to four different voltage signals: 0 volts, 2 / 3V0 volts, 1 / 2V0 volts, and V0 volts. This can intuitively reflect the mutual influence between the four loops A1-A2, A3-A2, A1-a, and A2-a. Example

[0069] like Figure 5 As shown in the figure, this embodiment provides a method for testing the characteristics of a load switch with a transfer interruption branch. The method further includes:

[0070] S4 fixes the displacement sensor between the moving contact shaft of the load switch under test and the arc-extinguishing chamber, thereby obtaining the displacement curve of the moving contact and the contact in the arc-extinguishing chamber relative to the time change during the opening process. According to the different time periods in the theoretical time sequence diagram of the level change, the time axis of the displacement curve is matched accordingly to obtain the time-displacement curve, thereby analyzing the abnormal situation of the moving contact and the arc-extinguishing chamber travel in each time period.

[0071] like Figure 6 As shown, displacement sensors are connected to both ends of the moving contact and the arc-extinguishing chamber to capture the displacement changes of the contacts at both ends of the moving contact and the arc-extinguishing chamber during the opening process. This yields displacement curves of the contacts in the moving contact and the arc-extinguishing chamber relative to time during the opening process. Figure 6 The time points t0-t5 marked on the horizontal axis and Figure 3 , Figure 4 Corresponding to the time points t0-t5 in the data, Figure 4 and Figure 6 By combining the time axes, the displacement timing during the circuit breaker tripping process can be obtained. Figure 7 . Figure 7 The displacement and timing diagrams provided are based on theoretical conditions. In actual testing, the displacement and timing diagrams obtained during the tripping process of the tested load switch will be compared with... Figure 4 Compare and analyze the travel of the moving contact blade and the arc-extinguishing chamber within each time interval, and check for any abnormalities in the timing diagrams obtained through the test circuit and oscilloscope. Example

[0072] This embodiment also provides a load switch characteristic testing device with a transfer breaking branch. The device includes the load switch under test, an oscilloscope, a test circuit, and a power supply module. The load switch under test includes a bracket, with a first supporting insulator and a second supporting insulator respectively installed at both ends of the bracket. The first supporting insulator has a terminal connected to the rear end of the moving contact blade. The second supporting insulator has a stationary contact. An arc-extinguishing chamber is located between the two blades of the moving contact blade. The rear end of the arc-extinguishing chamber is hinged to the moving contact blade. The contact piece at the front end of the arc-extinguishing chamber is inserted into the slot of the stationary contact. The front end of the moving contact blade is away from or close to the stationary contact. The positive and negative terminals of the test circuit are connected to the power supply module. The voltage acquisition point of the test circuit is connected to the relevant position of the load switch under test. The oscilloscope is connected to the voltage acquisition point to display the voltage signal at the current voltage acquisition point, thereby obtaining a timing diagram of the level change.

[0073] This embodiment provides a high-voltage vacuum load switch structure and a schematic diagram of its connection with a test circuit, as shown below. Figure 8 As shown, in this load switch, a pair of supporting insulators 1 for each phase are mounted at a certain angle on the bracket 2. One insulator has a terminal hinged to the rear end of the moving contact 3, and the other insulator has a stationary contact 4. A vacuum interrupter 5 is located between the two blades of the moving contact 3, with its rear end hinged to the moving contact. A tension spring 6 is connected between the rear ends of the vacuum interrupter 5 of the moving contact. The contact piece 7 at the front end of the vacuum interrupter 5 is inserted into the slot 8 of the stationary contact. The structure of the slot part is similar to... Figure 9 As shown, there is a protruding stop 9 on one side of the inner wall of the slot, and an irregularly shaped spring 10 on the other side of the inner wall. The irregularly shaped spring presses the contact piece 7 under the stop 9 on the opposite side, so that the contact piece 7 cannot move upward and disengage from the stationary contact.

[0074] like Figure 9 As shown, connect the three sets of oscilloscope probes to... Figure 8 Connect the power supply between "+" and "-" at points "a", "A1", "A2", and "A3", with a power supply voltage value of "V0". Fix the displacement sensor to the rotating shaft of the moving contact 3 and the two ends of the arc-extinguishing chamber 5. Measure the waveforms of points A3, A2, and a with respect to point A2 using an oscilloscope to obtain the actual timing diagram of the tested high-voltage vacuum load switch during the opening process in Example 1. Collect the actual travel curves obtained by the displacement sensors of the moving contact 3 and the vacuum arc-extinguishing chamber 5. Match the obtained actual timing diagram with the actual displacement travel curve according to each time point and combine them to form the actual displacement timing diagram and the theoretical displacement timing diagram provided in this embodiment. Figure 7By comparing and observing the anomalies in the timing waveforms and stroke curves, and identifying the time interval between which the anomalies occur, researchers can be guided to adjust the tripping action structure and provide assistance in optimizing the arc-extinguishing chamber structure.

[0075] like Figure 10 As shown, this is a displacement time series diagram recorded under an abnormal condition. The diagram shows fluctuations in the time series waveform near point A1 captured by the oscilloscope probe, and fluctuations also occur around time t1 in the arc-extinguishing chamber displacement curve. This can be observed by comparing the waveform with... Figure 7 By comparing the theoretical time-series displacement diagrams, the abnormal situation can be located near the moment when the current begins to transfer to the arc-extinguishing chamber during the tripping process. Figure 9 The given structural diagram of the high-voltage vacuum load switch under test shows that the fault point occurs near the moment when the moving contact blade fails to separate from the stationary contact and begins to contact one end of the arc-extinguishing chamber.

[0076] Although preferred embodiments of the invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including both the preferred embodiments and all changes and modifications falling within the scope of the invention.

[0077] Obviously, those skilled in the art can make various modifications and variations to the embodiments of the present invention without departing from the spirit and scope of the embodiments of the present invention. Thus, if these modifications and variations to the embodiments of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention also intends to include these modifications and variations.

Claims

1. A method for testing the characteristics of a load switch with a transfer breaking branch, characterized in that: The method includes: The first voltage acquisition point in the test circuit is connected to the moving contact of the load switch under test; the second voltage acquisition point in the test circuit is connected to the end of the arc-extinguishing chamber of the load switch under test that is furthest from the stationary contact; the third voltage acquisition point in the test circuit is connected to the stationary contact of the load switch under test; and the fourth voltage acquisition point in the test circuit is connected to the end of the arc-extinguishing chamber of the load switch under test that is closest to the stationary contact. The signal terminals of the three probes of the oscilloscope are respectively connected to the first, second, and third voltage acquisition points, and the ground wire of the oscilloscope is connected to the fourth voltage acquisition point. The load switch under test is tripped, and the voltage signals of the signal terminals are acquired at different time periods to obtain a time-series diagram of the level change at different voltage acquisition points. The time-series diagram of the level change is compared and analyzed with the corresponding theoretical time-series diagram to determine the mutual influence between different acquisition points. The method also includes: The displacement sensor is fixed between the moving contact blade shaft of the load switch under test and the arc-extinguishing chamber to obtain the displacement curve of the moving contact blade and the contact inside the arc-extinguishing chamber relative to time during the opening process. The displacement time sequence diagram is obtained by correspondingly combining the different time periods in the level change time sequence diagram with the time axis of the displacement curve diagram, thereby analyzing the abnormal situation of the moving contact blade and the arc-extinguishing chamber travel in each time period. The test circuit includes seven voltage-regulating resistors with the same resistance value. The first resistor R1 and the second resistor R2 are connected in series to form the second acquisition unit. The third resistor R3 and the fourth resistor R4 are connected in series to form the first acquisition unit. The fifth resistor R5 and the sixth resistor R6 are connected in series to form the third acquisition unit. The seventh resistor R7 is connected in parallel with the sixth resistor R6. The two ends of the first acquisition unit, the second acquisition unit and the third acquisition unit are respectively connected to the positive and negative terminals of the power module. The first voltage acquisition point is set between the third resistor R3 and the fourth resistor R4 in the first acquisition unit; the second voltage acquisition point is set between the first resistor R1 and the second resistor R2 in the second acquisition unit; the third voltage acquisition point is set between the fifth resistor R5 and the sixth resistor R6 in the third acquisition unit; and the fourth voltage acquisition point is set at the connection point of the sixth resistor R6 and the seventh resistor R7.

2. The method for testing the characteristics of a load switch with a transfer disconnecting branch according to claim 1, characterized in that: The process involves tripping the switch of the load under test and collecting voltage signals from the signal terminal at different time periods to obtain a time-series diagram of voltage level changes at different sampling points, including: Seven time points were determined during the tripping process of the tested load switch: t0, the time when the isolating switch of the tested load switch begins to trip and the moving contact begins to separate from the stationary contact; t1, the time when the current begins to transfer to the arc-extinguishing chamber; t2, the time when the moving contact and the stationary contact complete separation; t3, the time when the contacts inside the arc-extinguishing chamber complete separation; t4, the time when the trip unit of the arc-extinguishing device completes separation from the stationary contact; t5, the time when the contacts inside the arc-extinguishing chamber complete closing due to the self-closing force of the arc-extinguishing chamber; and t6, the time when the tested load switch is re-closed. The level changes considered at different voltage acquisition points include the level changes between the first and fourth voltage acquisition points, the level changes between the second and fourth voltage acquisition points, the level changes between the first and third voltage acquisition points, and the level changes between the fourth and third voltage acquisition points. Therefore, the timing diagrams of the above four level changes in different time periods were obtained respectively.

3. The method for testing the characteristics of a load switch with a transfer disconnecting branch according to claim 2, characterized in that: The process of obtaining the timing diagrams of the above four levels of change at different time periods includes: The values ​​at the seven time points are determined based on the test circuit. The level changes at different voltage acquisition points are expressed as a percentage relative to the power supply voltage, thereby obtaining the voltage values ​​between two different voltage acquisition points in different time periods. The voltage values ​​include the power supply voltage V0, zero, 2 / 3 V0, and 1 / 2 V0. The mutual influence between the four circuits is obtained based on the voltage values ​​between two different voltage acquisition points.

4. The method for testing the characteristics of a load switch with a transfer disconnecting branch according to claim 1, characterized in that: The resistance value of the voltage regulating resistor is set according to the power supply voltage value of the power supply module.

5. A load switch characteristic testing device with a transfer breaking branch, characterized in that: The device includes a load switch under test, an oscilloscope, a test circuit, and a power module. The load switch under test includes a bracket, with a first supporting insulator and a second supporting insulator mounted at both ends of the bracket. The first supporting insulator has a terminal connected to the rear end of a moving contact blade. The second supporting insulator has a stationary contact mounted on it. An arc-extinguishing chamber is located between the two blades of the moving contact blade, with its rear end hinged to the moving contact blade. The contact piece at the front end of the arc-extinguishing chamber is inserted into a slot in the stationary contact. The front end of the moving contact blade is either away from or close to the stationary contact. The positive and negative terminals of the test circuit are connected to the power module. The voltage acquisition points of the circuit are connected to the relevant positions of the load switch under test. The oscilloscope is connected to the voltage acquisition points to display the voltage signals between the two voltage acquisition points at different time periods, thereby obtaining a timing diagram of level changes. The first voltage acquisition point in the test circuit is connected to the moving contact of the load switch under test. The second voltage acquisition point in the test circuit is connected to the end of the arc-extinguishing chamber of the load switch under test that is away from the stationary contact. The third voltage acquisition point in the test circuit is connected to the stationary contact of the load switch under test. The fourth voltage acquisition point in the test circuit is connected to the end of the arc-extinguishing chamber of the load switch under test that is close to the stationary contact. The test circuit includes seven voltage-regulating resistors with the same resistance value. The first resistor R1 and the second resistor R2 are connected in series to form the second acquisition unit. The third resistor R3 and the fourth resistor R4 are connected in series to form the first acquisition unit. The fifth resistor R5 and the sixth resistor R6 are connected in series to form the third acquisition unit. The seventh resistor R7 is connected in parallel with the sixth resistor R6. The two ends of the first acquisition unit, the second acquisition unit and the third acquisition unit are respectively connected to the positive and negative terminals of the power module. The first voltage acquisition point is set between the third resistor R3 and the fourth resistor R4 in the first acquisition unit; the second voltage acquisition point is set between the first resistor R1 and the second resistor R2 in the second acquisition unit; the third voltage acquisition point is set between the fifth resistor R5 and the sixth resistor R6 in the third acquisition unit; and the fourth voltage acquisition point is set at the connection point of the sixth resistor R6 and the seventh resistor R7.

6. The load switch characteristic testing device with transfer disconnection branch according to claim 5, characterized in that: The device also includes a displacement sensor, which is disposed between the moving contact blade shaft of the load switch under test and the arc-extinguishing chamber.

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