Method and system for evaluating thermal breaking performance of high-voltage alternating-current gas circuit breaker

Abstract

The invention discloses a method and a system for evaluating the thermal breaking performance of a high-voltage alternating-current gas circuit breaker. The method comprises the following steps: setting a test loop; a first test is executed according to the operation process, a first parameter is measured, whether the test object is successfully cut off is judged, if yes, a first action is executed, and otherwise, a second action is executed; according to the first test, the thermal breaking capacity limit of the high-voltage alternating-current gas circuit breaker is obtained; a second test is executed according to the hot breaking capacity limit and the operation process, a first parameter is measured, whether breaking of the test object succeeds or not is judged, if yes, a third action is executed, and if not, a fourth action is executed; and according to the second test, obtaining a thermal breaking performance evaluation result of the high-voltage alternating-current gas circuit breaker. The invention provides a test loop which can comprehensively reproduce the on-off process of a circuit breaker and improve the evaluation accuracy. The thermal breaking performance of the circuit breaker is quantitatively evaluated by adjusting parameters, and data are closer to reality; and the test cost is reduced, the period is shortened, and fine test and efficient evaluation of the breaking process of the circuit breaker are realized.

Description

Technical Field

[0001] The present invention relates to the technical field of electrical equipment testing, and in particular to a method and system for evaluating the thermal breaking performance of a high-voltage AC gas circuit breaker. Background Art

[0002] When breaking the current, the gas circuit breaker needs to go through two key stages: thermal recovery and dielectric recovery. Within a few microseconds after the current passes through zero, although the arc conductivity is very small, there is still a post-arc current, resulting in energy input into the arc gap. At this time, if the energy dissipation is not enough to balance the input, the arc temperature will rise, the arc conductivity will increase, and it may cause the arc to reignite, that is, thermal breakdown. On the contrary, if the dissipated power continues to be higher than the input power, the arc temperature drops, and the conductivity decreases to a negligible level, entering the dielectric recovery stage. At this stage, the contacts need to withstand the transient recovery voltage (TRV) applied by the system. If the dielectric strength is always higher than the TRV, the circuit breaker is successfully opened; otherwise, the TRV exceeds the dielectric strength, which will cause electrical breakdown and the arc to reignite.

[0003] At present, the methods for evaluating the thermal breakdown performance of gas circuit breakers mainly include simulation calculations and simple experimental tests, but both have limitations. First, the arc theory is not yet perfect. The arc in the breaking process of the gas circuit breaker involves complex processes of multiple physical fields, including the interaction and coupling of electromagnetic fields, flow fields, and thermal fields. It is highly nonlinear and has complex changes in material composition and physical properties, resulting in slow development of arc theory. Although the existing Mayr and Cassie model has been improved, it still cannot accurately simulate the arc physical process, and the breaking capacity of the circuit breaker still needs to be verified by field tests.

[0004] Secondly, although the test circuit can simulate the change of the current change rate di / dt, it lacks a method to adjust the recovery voltage, so it is impossible to test the impact of the recovery voltage rise rate (RRRV) on the post-arc breaking process, especially in the TRV starting stage. In addition, the constants in the arc model rely on experimental acquisition, which limits the accuracy of the simulation calculation. Finally, the current calculation model and circuit do not consider the actual working conditions where di / dt changes synchronously with RRRV, and do not meet the requirements of the type test standard. The standard requires that the short-circuit current i changes synchronously with the RRRV, but the existing model and circuit do not consider this point, which has certain limitations. Summary of the invention

[0005] The purpose of this section is to summarize some aspects of embodiments of the present invention and briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this section and the specification abstract and the invention title of this application to avoid blurring the purpose of this section, the specification abstract and the invention title, and such simplifications or omissions cannot be used to limit the scope of the present invention.

[0006] In view of the above existing problems, the present invention is proposed. Therefore, the present invention provides a method for evaluating the thermal breaking performance of a high-voltage AC gas circuit breaker to solve the problem that the evaluation of the thermal breakdown performance of a gas circuit breaker in the prior art is inaccurate and incomplete, and cannot meet the requirements of actual working conditions and type test standards.

[0007] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0008] In a first aspect, the present invention provides a method for evaluating the thermal breaking performance of a high-voltage AC gas circuit breaker, comprising:

[0009] Set up the test circuit;

[0010] Perform test 1 according to the operation flow, measure the first parameter, and determine whether the test product is disconnected successfully. If successful, perform the first action, otherwise, perform the second action;

[0011] According to the first test, the thermal breaking capacity limit of the high voltage AC gas circuit breaker is obtained;

[0012] According to the thermal breaking capacity limit, perform test 2 according to the operation process, measure the first parameter, and determine whether the breaking of the test product is successful. If successful, perform the third action, otherwise, perform the fourth action;

[0013] According to the second test, a performance evaluation result of thermal breaking of a high-voltage AC gas circuit breaker is obtained.

[0014] As a preferred solution of the method for evaluating the thermal breaking performance of a high-voltage AC gas circuit breaker of the present invention, the test circuit includes a current source circuit, a voltage source circuit, a regulating circuit and a measuring circuit;

[0015] The current source loop and the measuring loop are connected in parallel, and the branch formed by the series connection of the regulating loop and the voltage source loop and the measuring loop are connected in parallel.

[0016] As a preferred solution of the method for evaluating the thermal breaking performance of a high-voltage AC gas circuit breaker according to the present invention, the first test is performed according to the operating procedure, including:

[0017] Set the initial value of the test 1 parameter, perform the test 1 according to the operation process, measure the first parameter, and determine whether the test product is disconnected successfully;

[0018] If the test product is disconnected successfully, the first action is executed; if the test product is disconnected unsuccessfully, the second action is executed, and the test 1 is continued to be executed according to the operation flow to measure the first parameter;

[0019] After executing the first action, perform the test one according to the operation flow to determine whether the breaking of the test product is successful. If the breaking of the test product fails, the test one ends, and the thermal breaking capacity limit of the high-voltage AC gas circuit breaker is obtained. On the contrary, if the breaking of the test product is successful, perform the first action to determine whether the breaking of the test product is successful, and repeat the first action until the breaking of the test product fails. Then the test one ends, and the thermal breaking capacity limit of the high-voltage AC gas circuit breaker is obtained.

[0020] After executing the second action, perform test one according to the operation process to determine whether the test product is successfully broken. If the test product is successfully broken, the test one ends and the thermal breaking capacity limit of the high-voltage AC gas circuit breaker is obtained. On the contrary, if the test product fails to break, perform the second action to determine whether the test product is successfully broken, and repeat the second action until the test product is successfully broken. Then the test one ends and the thermal breaking capacity limit of the high-voltage AC gas circuit breaker is obtained.

[0021] As a preferred solution of the method for evaluating the thermal breaking performance of a high-voltage AC gas circuit breaker according to the present invention, the following steps are performed according to the operating procedure:

[0022] According to the thermal breaking capacity limit obtained in test one, set the initial value of the test two parameter, measure the first parameter, and judge whether the test product breaks successfully;

[0023] If the test product is disconnected successfully, the third action is executed; if the test product is disconnected unsuccessfully, the fourth action is executed, and the second test is continued according to the operation flow to measure the first parameter;

[0024] After executing the third action, perform the second test according to the operation process to determine whether the test product is successfully broken. If the test product fails to break, the second test ends, and the performance evaluation result of the thermal breaking of the high-voltage AC gas circuit breaker is obtained. On the contrary, if the test product is successfully broken, perform the third action to determine whether the test product is successfully broken, and repeat the third action until the test product fails to break, then the second test ends, and the performance evaluation result of the thermal breaking of the high-voltage AC gas circuit breaker is obtained.

[0025] After executing the fourth action, perform the second test according to the operation process to determine whether the test product is successfully broken. If the test product is successfully broken, the second test ends and the performance evaluation result of the thermal breaking of the high-voltage AC gas circuit breaker is obtained. On the contrary, if the test product fails to break, the fourth action is executed to determine whether the test product is successfully broken. The fourth action is repeated until the test product is successfully broken. Then the second test ends and the performance evaluation result of the thermal breaking of the high-voltage AC gas circuit breaker is obtained.

[0026] As a preferred solution of the method for evaluating the thermal breaking performance of a high-voltage AC gas circuit breaker according to the present invention, the first action and the second action include:

[0027] The first action is to increase the voltage according to a preset first voltage step;

[0028] The second action is to reduce the voltage according to a preset second voltage step.

[0029] As a preferred solution of the method for evaluating the thermal breaking performance of a high-voltage AC gas circuit breaker according to the present invention, the third action and the fourth action include:

[0030] The third action is to increase the resistance according to the preset first resistance step length;

[0031] The fourth action is to reduce the resistance according to a preset second resistance step.

[0032] As a preferred solution of the method for evaluating the thermal breaking performance of a high-voltage AC gas circuit breaker according to the present invention, the method of judging whether the breaking of the test product is successful includes:

[0033] The method for judging whether the test product is successfully broken is whether the high-voltage AC gas circuit breaker breaks down again after zero crossing.

[0034] In a second aspect, the present invention provides a system for evaluating the thermal breaking performance of a high-voltage AC gas circuit breaker, comprising:

[0035] Loop setting module, used to set the test loop;

[0036] A primary test module is used to perform a test 1 according to the operation process, measure a first parameter, determine whether the test product is successfully disconnected, and if successful, perform a first action, otherwise, perform a second action; according to the test 1, obtain the thermal breaking capacity limit of the high-voltage AC gas circuit breaker;

[0037] The secondary test module is used to perform the second test according to the operation process based on the thermal breaking capacity limit, measure the first parameter, and determine whether the test product is successfully broken. If successful, execute the third action, otherwise, execute the fourth action; according to the second test, obtain the performance evaluation result of the thermal breaking of the high-voltage AC gas circuit breaker.

[0038] In a third aspect, the present invention provides a computing device, comprising:

[0039] Memory and processor;

[0040] The memory is used to store computer executable instructions, and the processor is used to execute the computer executable instructions. When the computer executable instructions are executed by the processor, the steps of the method for evaluating the thermal breaking performance of a high-voltage AC gas circuit breaker are implemented.

[0041] In a fourth aspect, the present invention provides a computer-readable storage medium storing computer-executable instructions, which, when executed by a processor, implement the steps of the method for evaluating the thermal breaking performance of a high-voltage AC gas circuit breaker.

[0042] Compared with the prior art, the present invention has the following beneficial effects:

[0043] 1) The present invention provides a test circuit, in which the test current and voltage are provided by a synthetic circuit, and the stress applied to the circuit breaker is basically the same as that of the type test. The current and voltage provided simultaneously by the circuit are equivalent to those in actual applications, which improves the accuracy and comprehensiveness of the evaluation results compared to the common test circuit that only provides current. Compared with theoretical calculations, the complex electromagnetic thermal process during the circuit breaker opening and closing process is fully reproduced, which is closer to reality and avoids the limitations of the model. The test circuit can simultaneously collect post-arc current, arc voltage and recovery voltage, thereby realizing a detailed test of the circuit breaker opening and closing process;

[0044] 2) Without changing the reactance and reactance in the test circuit, when changing the charging voltage, the typical process of obtaining the thermal breaking capacity limit of the gas circuit breaker by adjusting the di / dt is used to quantitatively evaluate the post-arc thermal breaking performance of the circuit breaker under different di / dt and RRRV;

[0045] 3) When the thermal breaking performance of the circuit breaker needs to be carefully evaluated, the voltage remains unchanged, other equipment parameters remain unchanged, and the U L Peak U Lm The free adjustment can quantitatively evaluate the post-arc thermal breakdown characteristics of the circuit breaker under different RRRV when di / dt remains unchanged, which can replace the model calculation and the data obtained is closer to reality;

[0046] 4) The test circuit of the present invention reduces the cost of building, modifying and operating the test circuit and shortens the test cycle. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative labor. Among them:

[0048] Figure 1 It is a schematic diagram of the overall process of a method for evaluating the thermal breaking performance of a high-voltage AC gas circuit breaker according to an embodiment of the present invention;

[0049] Figure 2A schematic diagram of a test circuit of a method for evaluating the thermal breaking performance of a high-voltage AC gas circuit breaker according to an embodiment of the present invention;

[0050] Figure 3 A schematic diagram of a TRV waveform of a method for evaluating the thermal breaking performance of a high-voltage AC gas circuit breaker according to an embodiment of the present invention;

[0051] Figure 4 A schematic diagram of a flow chart of obtaining the thermal breaking capacity limit of a gas circuit breaker by adjusting di / dt in a method for evaluating the thermal breaking performance of a high-voltage AC gas circuit breaker according to an embodiment of the present invention;

[0052] Figure 5 A schematic flow chart of a method for evaluating the thermal breaking performance of a high-voltage AC gas circuit breaker according to an embodiment of the present invention for obtaining the RRRV limit tolerance capacity of a gas circuit breaker by changing a RRRV regulating loop. DETAILED DESCRIPTION

[0053] In order to make the above-mentioned purposes, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the drawings of the specification. Obviously, the described embodiments are part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary persons in the art without creative work should fall within the scope of protection of the present invention.

[0054] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0055] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The term "in one embodiment" that appears in different places in this specification does not necessarily refer to the same embodiment, nor does it refer to a separate or selective embodiment that is mutually exclusive with other embodiments.

[0056] The present invention is described in detail with reference to schematic diagrams. When describing the embodiments of the present invention, for the sake of convenience, the cross-sectional diagrams showing the device structure will not be partially enlarged according to the general scale, and the schematic diagrams are only examples, which should not limit the scope of protection of the present invention. In addition, in actual production, the three-dimensional dimensions of length, width and depth should be included.

[0057] At the same time, in the description of the present invention, it should be noted that the orientations or positional relationships indicated by the terms "upper, lower, inner and outer" are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the system or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first, second or third" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0058] In the present invention, unless otherwise clearly specified and limited, the terms "install, connect, connect" should be understood in a broad sense, for example: it can be a fixed connection, a detachable connection or an integral connection; it can also be a mechanical connection, an electrical connection or a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0059] Example 1

[0060] Before describing this embodiment, the relevant terms are explained first;

[0061] High-voltage AC gas circuit breaker: a circuit breaker that uses gas as the insulating and breaking medium, such as compressed air circuit breakers, SF6 circuit breakers, and other gas (such as clean air, nitrogen, carbon dioxide, C4F7N mixed gas, etc.) circuit breakers, etc.;

[0062] RRRV: recovery voltage rise rate, that is, the ratio of the recovery voltage peak to the time t from rising to the peak;

[0063] di / dt: The slope of the current relative to time when the current crosses zero;

[0064] RRRV coefficient (s): The rate of rise of voltage under unit current, in kV / μs / kA.

[0065] Reference Figure 1-5 , as an embodiment of the present invention, provides a method for evaluating the thermal breaking performance of a high-voltage AC gas circuit breaker, comprising:

[0066] S100: Set up a test circuit;

[0067] Preferably, the test circuit includes a current source circuit, a voltage source circuit, a regulation circuit and a measurement circuit;

[0068] The current source loop and the measuring loop are connected in parallel, and the branch formed by the series connection of the regulating loop and the voltage source loop and the measuring loop are connected in parallel.

[0069] S102: Execute test 1 according to the operation process, measure the first parameter, determine whether the test product is successfully disconnected, if successful, execute the first action, otherwise, execute the second action; according to test 1, obtain the thermal breaking capacity limit of the high-voltage AC gas circuit breaker;

[0070] In the embodiment of the present application, the first parameter is the arc current and the arc voltage U sp , di / dt and RRRV and other parameters;

[0071] In the embodiment of the present application, the operation process of performing the test is:

[0072] (1) Initially, the auxiliary switch AB1 and the test piece SP are in the closed position. First, the current loop capacitor group Cs and the voltage loop capacitor CS1 are charged to the calculated values ​​respectively.

[0073] (2) After charging is completed, the gap GP1 ignites at time T1, the circuit is connected, and the test sample SP issues a trip command at time T1, and the test sample starts to trip;

[0074] (3) The ignition ball GP ignites before the current of the test object SP passes through zero, the voltage source loop is connected, and the high-frequency current flows through the test object SP, superimposing with the current of the current source loop to form a zero-crossing point. At the same time, the auxiliary switch AB1 is opened to separate the current source loop from the voltage source loop.

[0075] (4) The SP of the test sample is disconnected at the current zero point, the SP branch of the test sample is disconnected, and the capacitor CS1 discharges through the resistor R1, the capacitor C1, the resistor R2, the capacitor C2, the reactance Ls, and the capacitor Cd to form TRV. The RRRV regulating branch changes the RRRV of TRV in the initial stage (usually 0-30μs) by self-discharge, see Figure 3 Starting part.

[0076] Preferably, an initial value of the test parameter is set, the test is performed according to the operation flow, the first parameter is measured, and it is determined whether the test product is disconnected successfully;

[0077] Preferably, if the test product is disconnected successfully, the first action is performed; if the test product is disconnected unsuccessfully, the second action is performed, and the test 1 is continued to be performed according to the operation flow to measure the first parameter;

[0078] Preferably, after executing the first action, test one is performed according to the operation flow to determine whether the test product is successfully broken. If the test product fails to break, test one is ended, and the thermal breaking capacity limit of the high-voltage AC gas circuit breaker is obtained. Conversely, if the test product is successfully broken, the first action is performed to determine whether the test product is successfully broken, and the first action is repeatedly performed until the test product fails to break, then test one is ended, and the thermal breaking capacity limit of the high-voltage AC gas circuit breaker is obtained.

[0079] Preferably, after executing the second action, test one is performed according to the operating process to determine whether the test product is successfully broken. If the test product is successfully broken, test one is completed and the thermal breaking capacity limit of the high-voltage AC gas circuit breaker is obtained. Conversely, if the test product fails to break, the second action is performed to determine whether the test product is successfully broken. The second action is repeatedly performed until the test product is successfully broken, then test one is completed and the thermal breaking capacity limit of the high-voltage AC gas circuit breaker is obtained.

[0080] In the embodiment of the present application, the first action is to increase the voltage according to a preset first voltage step; the second action is to reduce the voltage according to a preset second voltage step;

[0081] In an optional embodiment, the first voltage step size and the second voltage step size are set according to gas AC circuit breakers of different voltage levels and test circuit parameters.

[0082] In the embodiment of the present application, the method for judging whether the breaking of the test product is successful is whether the high-voltage AC gas circuit breaker breaks down again after zero crossing.

[0083] S104: according to the thermal breaking capacity limit, perform the second test according to the operation process, measure the first parameter, and determine whether the breaking of the test product is successful. If successful, perform the third action, otherwise, perform the fourth action; according to the second test, obtain the performance evaluation result of the thermal breaking of the high-voltage AC gas circuit breaker;

[0084] Preferably, according to the thermal breaking capacity limit obtained in the first test, the initial value of the second test parameter is set, the first parameter is measured, and it is determined whether the breaking of the test product is successful;

[0085] Preferably, if the test product is disconnected successfully, the third action is performed; if the test product is disconnected unsuccessfully, the fourth action is performed, and the test 2 is continued to be performed according to the operation flow to measure the first parameter;

[0086] Preferably, after executing the third action, the second test is performed according to the operation process to determine whether the test product is successfully broken. If the test product fails to break, the second test is terminated, and the performance evaluation result of the thermal breaking of the high-voltage AC gas circuit breaker is obtained; otherwise, if the test product is successfully broken, the third action is performed to determine whether the test product is successfully broken, and the third action is repeatedly performed until the test product fails to break, then the second test is terminated, and the performance evaluation result of the thermal breaking of the high-voltage AC gas circuit breaker is obtained;

[0087] Preferably, after executing the fourth action, test two is performed according to the operating process to determine whether the test product is successfully broken. If the test product is successfully broken, test two is completed and a performance evaluation result of the thermal breaking of the high-voltage AC gas circuit breaker is obtained. Conversely, if the test product fails to break, the fourth action is performed to determine whether the test product is successfully broken. The fourth action is repeated until the test product is successfully broken, then test two is completed and a performance evaluation result of the thermal breaking of the high-voltage AC gas circuit breaker is obtained.

[0088] In the embodiment of the present application, the third action is to increase the resistance according to the preset first resistance step; the fourth action is to reduce the resistance according to the preset second resistance step;

[0089] In an optional embodiment, the first resistance step length is greater than the second resistance step length, for example, the first resistance step length is equal to twice the second resistance step length.

[0090] In the embodiment of the present application, the method for judging whether the breaking of the test product is successful is whether the high-voltage AC gas circuit breaker breaks down again after zero crossing.

[0091] The above is a schematic scheme of a method for evaluating the thermal breaking performance of a high-voltage AC gas circuit breaker in this embodiment. It should be noted that the technical scheme of the system for evaluating the thermal breaking performance of a high-voltage AC gas circuit breaker and the technical scheme of the method for evaluating the thermal breaking performance of a high-voltage AC gas circuit breaker described above belong to the same concept, and the details of the technical scheme of the system for evaluating the thermal breaking performance of a high-voltage AC gas circuit breaker in this embodiment that are not described in detail can all be referred to the description of the technical scheme of the method for evaluating the thermal breaking performance of a high-voltage AC gas circuit breaker described above.

[0092] The high-voltage AC gas circuit breaker thermal breaking performance evaluation system in this embodiment includes:

[0093] Loop setting module, used to set the test loop;

[0094] The primary test mode is used to perform the first test according to the operation process, measure the first parameter, and determine whether the test product is successfully disconnected. If successful, the first action is executed, otherwise, the second action is executed; according to the first test, the thermal breaking capacity limit of the high-voltage AC gas circuit breaker is obtained;

[0095] The secondary test module is used to perform the second test according to the operation process based on the thermal breaking capacity limit, measure the first parameter, and determine whether the test product is successfully broken. If successful, execute the third action, otherwise, execute the fourth action; according to the second test, obtain the performance evaluation result of the thermal breaking of the high-voltage AC gas circuit breaker.

[0096] This embodiment further provides a computing device, which is applicable to the situation of evaluating the thermal breaking performance of a high-voltage AC gas circuit breaker, and includes:

[0097] Memory and processor; the memory is used to store computer executable instructions, and the processor is used to execute computer executable instructions to implement the method for evaluating the thermal breaking performance of a high-voltage AC gas circuit breaker as proposed in the above embodiment.

[0098] This embodiment further provides a storage medium on which a computer program is stored. When the program is executed by a processor, the method for evaluating the thermal breaking performance of a high-voltage AC gas circuit breaker proposed in the above embodiment is implemented.

[0099] The storage medium proposed in this embodiment and the method for evaluating the thermal breaking performance of a high-voltage AC gas circuit breaker proposed in the above embodiment belong to the same inventive concept. The technical details not described in detail in this embodiment can be referred to the above embodiment, and this embodiment has the same beneficial effects as the above embodiment.

[0100] Through the above description of the implementation methods, the technicians in the relevant field can clearly understand that the present invention can be implemented by means of software and necessary general hardware, and of course can also be implemented by hardware, but in many cases the former is a better implementation method. Based on such an understanding, the technical solution of the present invention is essentially or the part that contributes to the prior art can be embodied in the form of a software product, and the computer software product can be stored in a computer-readable storage medium, such as a computer floppy disk, read-only memory (ReadOnly, Memory, ROM), random access memory (RandomAccess Memory, RAM), flash memory (FLASH), hard disk or optical disk, etc., including a number of instructions for a computer device (which can be a personal computer, server, or network device, etc.) to perform the methods of various embodiments of the present invention.

[0101] Example 2

[0102] Before describing this embodiment, the relevant terms are explained first;

[0103] High-voltage AC gas circuit breaker: a circuit breaker that uses gas as the insulating and breaking medium, such as compressed air circuit breakers, SF6 circuit breakers, and other gas (such as clean air, nitrogen, carbon dioxide, CF4 and other mixed gases) circuit breakers, etc.;

[0104] RRRV: Recovery voltage rise rate, that is, the ratio of the recovery voltage peak to the time t from rising to the peak.

[0105] Reference Figure 2-3 , Figure 2 The invention is a zero-zone thermal breaking performance evaluation test circuit for a gas AC circuit breaker, comprising a current source circuit, a voltage source circuit, a RRRV regulating circuit and a measuring circuit. The current source circuit and the measuring circuit are connected in parallel, and a branch formed by the RRRV regulating circuit and the voltage source circuit being connected in series is connected in parallel with the measuring circuit.

[0106] In the embodiment of the present application, the current source circuit provides a short-circuit current for the gas AC circuit breaker, and includes a capacitor C S , reactance L1, gap GP1, starting auxiliary switch AB1 and ammeter A1, capacitor C S , reactance L1, gap GP1, starting auxiliary switch AB1 and ammeter A1 are connected in series, and ammeter A1 is grounded;

[0107] In an optional embodiment, the current source loop can be replaced by an inductive energy storage system, which includes a high energy density inductor, a fast discharge switch, such as a spark gap or a vacuum switch, and a current regulating element.

[0108] In the embodiment of the present application, the voltage source circuit provides the gas AC circuit breaker with a recovery voltage TRV after breaking. The TRV waveform is shown in FIG. Figure 3 , the voltage source loop includes capacitor C S1 , reactance Ls, gap GP, resistor R1, capacitor C1, resistor R2, capacitor C2, reactance L2, capacitor C d , ammeter A3, etc., the first series branch formed by the series connection of resistor R2 and capacitor C2 is connected in parallel with the reactance L2 to form a first parallel branch, the first parallel branch, resistor R1 and capacitor C1 are connected in series to form a second series branch; reactance Ls, gap GP and capacitor C S1 The second series branch and the third series branch are connected in parallel, the second series branch and the ammeter A3 are connected in series to form a fourth series branch, and the fourth series branch and the capacitor C d In parallel, capacitor C d Grounding;

[0109] In an optional embodiment, the voltage source loop may use a multi-stage discharge technique to simulate different voltage conditions that the circuit breaker may encounter in an actual power grid; for example, by adding additional capacitor banks, discharge switches, and timing controllers to the circuit.

[0110] In the embodiment of the present application, the RRRV regulating circuit is used to adjust the RRRV of the voltage recovery at both ends of the gas AC circuit breaker after breaking, and the waveform generated by the oscillation is as follows: Figure 3 As shown. The RRRV regulation circuit includes a parallel reactance L 01 , a first branch and a resistor Rp, the first branch includes a first sub-parallel branch, a second sub-parallel branch and a capacitor C connected in series in sequence 01 , the first parallel branch includes the parallel reactance L R and resistance R, the second sub-parallel branch includes a parallel reactance L 02 and capacitor C 02 ;

[0111] In an optional embodiment, the RRRV regulation loop may introduce adjustable reactors and capacitors. For example, the reactors L01, LR, L02 and the capacitors C01, C02 may be tunable elements. By adjusting their inductance and capacitance values, the oscillation frequency and damping ratio of the RRRV waveform may be changed, thereby simulating different power system conditions.

[0112] In an optional embodiment, in order to increase the flexibility and adaptability of the RRRV regulation loop, additional switching elements, such as relays or semiconductor switches, etc., may be added to the first branch or the entire RRRV regulation loop.

[0113] In the embodiment of the present application, the measurement circuit includes a gas AC circuit breaker under test, a current sensor A2 and a voltage sensor: the device under test is also called a test product SP, the voltage sensor is connected in parallel with the test product SP, the current sensor A2 is connected in series with the test product SP, and the measured characteristic quantity includes the break voltage (U r ), the voltage sensor is used to measure the arc voltage (U sp ), the current sensor is used to measure the arc current, post-arc current (Isp), etc. during the breaking process of the test piece.

[0114] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

[0115] Example 3

[0116] Before describing this embodiment, the relevant terms are explained first;

[0117] Gas circuit breaker: a circuit breaker that uses gas as the insulating and breaking medium, such as compressed air circuit breakers, SF6 circuit breakers, and other gas (such as clean air, nitrogen, carbon dioxide, CF4 and other mixed gases) circuit breakers, etc.

[0118] RRRV: recovery voltage rise rate, that is, the ratio of the recovery voltage peak to the time t from rising to the peak;

[0119] di / dt: The slope of the current relative to time when the current crosses zero;

[0120] RRRV coefficient (s): The rate of rise of voltage under unit current, in kV / μs / kA.

[0121] Reference Figure 3-4 , the process of test 1 is as follows:

[0122] Initially, the auxiliary switch AB1 and the test product SP are in the closed position. First, the current loop capacitor group Cs and the voltage loop capacitor C S1Charge to the calculated value. After charging is completed, the gap GP1 ignites at T1, the circuit is connected, the test sample SP issues a trip command at T1, and the test sample starts to trip; the ignition ball GP ignites before the sample current passes through zero, the voltage circuit is connected, and the high-frequency current flows through the test sample SP, superimposed with the current source circuit current, forming a zero-crossing point. The test sample SP is disconnected at the current zero-crossing point, the test sample SP branch is disconnected, and the capacitor C S1 Through resistor R1, capacitor C1, resistor R2, capacitor C2, reactance Ls, capacitor C d The RRRV regulating branch changes the RRRV of TRV in the initial stage (usually 0-30μs) by self-discharge. Figure 3 Starting part.

[0123] By using the above circuit, the post-arc current of the gas AC circuit breaker under different di / dt and RRRV conditions can be tested and recorded, and the critical RRRV and di / dt of the thermal breakdown of the gas AC circuit breaker can be obtained, so as to quantitatively evaluate the thermal breaking performance of the gas AC circuit breaker. The evaluation process of changing di / dt can be referred to Figure 4 .pass Figure 4 The process can obtain the ultimate thermal breaking capability of the gas AC circuit breaker, that is, whether the circuit breaker has the breaking capability under certain di / dt and RRRV conditions.

[0124] The method for obtaining the thermal breaking capacity limit of a gas AC circuit breaker by adjusting di / dt comprises the following steps:

[0125] Step 1: Set the initial values ​​of test parameters according to requirements or historical data;

[0126] Step 2: Perform the test according to the operating procedures, measure and record the post-arc current and arc voltage U sp , di / dt and RRRV and other parameters;

[0127] Step 3: Determine whether the SP of the test product is disconnected successfully. If successful, jump to step 4; otherwise, jump to step 7;

[0128] Step 4: Increase the capacitor C according to the preset first voltage step. s The charging voltage U c and capacitor C S1 The charging voltage U cs1 ;

[0129] Step 5: Perform the test according to the operating procedures, measure and record the post-arc current and arc voltage U sp , di / dt, RRRV and other parameters;

[0130] Step 6, determine whether the SP of the test product is successfully disconnected. If successful, jump to step 4, otherwise, the process ends; the RRRV and di / dt at the end of the process are the thermal breakdown critical RRRV and critical di / dt of the gas AC circuit breaker.

[0131] Step 7: Reduce the capacitor C according to the preset second voltage step. s The charging voltage U c and capacitor C S1 The charging voltage U cs1 ;

[0132] Step 8: Perform the test according to the operating procedures, measure and record the post-arc current and arc voltage U sp , di / dt, RRRV and other parameters;

[0133] Step 9: Determine whether the SP of the test product is successfully disconnected. If not, jump to step 7. Otherwise, the process ends. The RRRV and di / dt at the end of the process are the critical RRRV and critical di / dt of the thermal breakdown of the gas AC circuit breaker.

[0134] It should be noted that the principle of adjusting di / dt is:

[0135] Change capacitor C in the same proportion s 、Capacitor C S1 The charging voltage U cs、 U cs1 Because the gas AC circuit breaker is in a circuit provided by the voltage source alone for a short period of time before the current passes through zero, only the current flowing through the voltage source flows. Therefore, the charging voltage U of the capacitor Cs1 is changed. cs , due to the short-circuit current through the sample Where ω is the angular frequency of the test current, Ls is the reactance value of the reactance Ls, then It can be seen that when the loop parameters do not change, di / dt and U cs、 U cs1 Proportional, so changing the charging voltage can change the di / dt of the short-circuit current. At the same time, since the parameters of the TRV and RRRV regulation loop equipment have not changed, the oscillation frequency and peak time of the recovery voltage do not change, only the recovery voltage peak changes, and thus RRRV changes at the same time.

[0136] use Figure 4 The process is to set a suitable step size, and through multiple tests, find the thermal breaking capacity limit of the gas AC circuit breaker, that is, the thermal breakdown critical RRRV and critical di / dt. The step size is appropriately set according to the gas AC circuit breakers of different voltage levels and the test circuit conditions.

[0137] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

[0138] Example 4

[0139] Before describing this embodiment, the relevant terms are explained first;

[0140] Gas circuit breaker: a circuit breaker that uses gas as the insulating and breaking medium, such as compressed air circuit breakers, SF6 circuit breakers and other gas (such as clean air, nitrogen, carbon dioxide, CF4 and other mixed gases) circuit breakers.

[0141] Transient recovery voltage (TRV): After the current stops flowing through the circuit breaker contacts, an instantaneous recovery voltage will be generated between the two ends (breaks) of the moving and static contacts.

[0142] RRRV: Recovery voltage rise rate, that is, the ratio of the recovery voltage peak to the time t from rising to the peak.

[0143] di / dt: The slope of current relative to time when the current passes through zero.

[0144] RRRV coefficient (s): The rate of rise of voltage under unit current, in kV / μs / kA.

[0145] In particular, you can also Figure 5 The process, without changing the test circuit, uses the adjustment of the RRRV regulating circuit equipment parameters to achieve a detailed evaluation of the thermal breaking performance of the gas AC circuit breaker, and obtains the ultimate tolerance capacity of the RRRV of the gas AC circuit breaker under fixed di / dt conditions, that is, Test 2.

[0146] The RRRV limit tolerance capability of the gas AC circuit breaker is obtained by changing the RRRV regulation loop, including the following steps:

[0147] S1. According to the critical RRRV and di / dt obtained from the test results in Example 2, set the initial values ​​of the first test parameters (set according to the technical parameters of the circuit breaker under test or the test requirements);

[0148] S2. Perform the test according to the operating procedures, measure and record the post-arc current and arc voltage U sp , di / dt and RRRV and other parameters;

[0149] S3, determine whether the SP of the test product is disconnected successfully, if successful, jump to step S4, otherwise jump to step S7;

[0150] S4, increasing the resistance value of the resistor Rp according to a preset first resistance step;

[0151] S5. Perform the test according to the operating procedures, measure and record the post-arc current and arc voltage U sp , di / dt, RRRV and other parameters;

[0152] S6, determine whether the SP of the test product is disconnected successfully. If successful, jump to step S4, otherwise, the process ends;

[0153] S7, reducing the resistance value of the resistor Rp according to a preset second resistance step length;

[0154] S8. Perform the test according to the operating procedures, measure and record the post-arc current and arc voltage U sp , di / dt, RRRV and other parameters;

[0155] S9, judging whether the SP of the test product is disconnected successfully, if not, jump to step S7, otherwise, the process ends.

[0156] Preferably, the step adjustment strategy of the resistance value of Rp is: first resistance step = 2*second resistance step.

[0157] The method to adjust RRRV is:

[0158] Capacitor C s 、Capacitor C S1 The charging voltage U cs and U cs1 Keep it constant, and change the resistance value of resistor Rp to change RRRV. s The charging voltage U cs In the RRRV regulation loop, the oscillation frequency is determined by the parameter components of the reactance L1 and the capacitor C 01 To determine, when the adjustment range is not large, due to the reactance L1 and capacitor C 01 The voltage is not changed, so the recovery voltage rises to the peak voltage (T L ) time changes very little, and the linearity of the recovery voltage will not be affected. p The first peak value of transient recovery voltage (U L ) has a greater impact and a larger resistance value (0-6000Ω), so it can be changed by changing R p To change the first peak value of the recovery voltage, so as to achieve the purpose of changing the starting part RRRV. p As the resistance value increases, RRRV increases, and the resistance Rp By increasing or decreasing Rp, the critical value of thermal breakdown of the gas AC circuit breaker can be obtained when di / dt remains unchanged.

[0159] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A method for evaluating the thermal breaking performance of a high-voltage AC gas circuit breaker, characterized in that: include: Set up the test circuit; Perform test 1 according to the operation flow, measure the first parameter, and determine whether the test product is disconnected successfully. If successful, perform the first action, otherwise, perform the second action; According to the first test, the thermal breaking capacity limit of the high voltage AC gas circuit breaker is obtained; According to the thermal breaking capacity limit, perform test 2 according to the operation process, measure the first parameter, and determine whether the breaking of the test product is successful. If successful, perform the third action, otherwise, perform the fourth action; According to the second test, a performance evaluation result of thermal breaking of a high-voltage AC gas circuit breaker is obtained.

2. The method for evaluating the thermal breaking performance of a high-voltage AC gas circuit breaker according to claim 1, characterized in that: The test circuit includes current source circuit, voltage source circuit, regulation circuit and measurement circuit; The current source loop and the measuring loop are connected in parallel, and the branch formed by the series connection of the regulating loop and the voltage source loop and the measuring loop are connected in parallel.

3. The method for evaluating the thermal breaking performance of a high-voltage AC gas circuit breaker according to claim 1 or 2, characterized in that: Perform the test according to the operating procedures, including: Set the initial value of the test 1 parameter, perform the test 1 according to the operation process, measure the first parameter, and determine whether the test product is disconnected successfully; If the test product is disconnected successfully, the first action is executed; if the test product is disconnected unsuccessfully, the second action is executed, and the test 1 is continued to be executed according to the operation flow to measure the first parameter; After executing the first action, perform the test one according to the operation flow to determine whether the breaking of the test product is successful. If the breaking of the test product fails, the test one ends, and the thermal breaking capacity limit of the high-voltage AC gas circuit breaker is obtained. On the contrary, if the breaking of the test product is successful, perform the first action to determine whether the breaking of the test product is successful, and repeat the first action until the breaking of the test product fails. Then the test one ends, and the thermal breaking capacity limit of the high-voltage AC gas circuit breaker is obtained. After executing the second action, perform test one according to the operation process to determine whether the test product is successfully broken. If the test product is successfully broken, the test one ends and the thermal breaking capacity limit of the high-voltage AC gas circuit breaker is obtained. On the contrary, if the test product fails to break, perform the second action to determine whether the test product is successfully broken, and repeat the second action until the test product is successfully broken. Then the test one ends and the thermal breaking capacity limit of the high-voltage AC gas circuit breaker is obtained.

4. The method for evaluating the thermal breaking performance of a high-voltage AC gas circuit breaker according to claim 3, characterized in that: Perform test 2 according to the operating procedures, including: According to the thermal breaking capacity limit obtained in test one, set the initial value of the test two parameter, measure the first parameter, and judge whether the test product breaks successfully; If the test product is disconnected successfully, the third action is executed; if the test product is disconnected unsuccessfully, the fourth action is executed, and the second test is continued according to the operation flow to measure the first parameter; After executing the third action, perform the second test according to the operation process to determine whether the test product is successfully broken. If the test product fails to break, the second test ends, and the performance evaluation result of the thermal breaking of the high-voltage AC gas circuit breaker is obtained. On the contrary, if the test product is successfully broken, perform the third action to determine whether the test product is successfully broken, and repeat the third action until the test product fails to break, then the second test ends, and the performance evaluation result of the thermal breaking of the high-voltage AC gas circuit breaker is obtained. After executing the fourth action, perform the second test according to the operation process to determine whether the test product is successfully broken. If the test product is successfully broken, the second test ends and the performance evaluation result of the thermal breaking of the high-voltage AC gas circuit breaker is obtained. On the contrary, if the test product fails to break, the fourth action is executed to determine whether the test product is successfully broken. The fourth action is repeated until the test product is successfully broken. Then the second test ends and the performance evaluation result of the thermal breaking of the high-voltage AC gas circuit breaker is obtained.

5. The method for evaluating the thermal breaking performance of a high-voltage AC gas circuit breaker according to claim 4, characterized in that: The first action and the second action include, The first action is to increase the voltage according to a preset first voltage step; The second action is to reduce the voltage according to a preset second voltage step.

6. The method for evaluating the thermal breaking performance of a high-voltage AC gas circuit breaker according to claim 5, characterized in that: The third and fourth actions include, The third action is to increase the resistance according to the preset first resistance step length; The fourth action is to reduce the resistance according to a preset second resistance step.

7. The method for evaluating the thermal breaking performance of a high-voltage AC gas circuit breaker according to claim 6, characterized in that: Judging whether the test product is disconnected successfully includes: The method for judging whether the test product is successfully broken is whether the high-voltage AC gas circuit breaker breaks down again after zero crossing.

8. A system for evaluating the thermal breaking performance of a high-voltage AC gas circuit breaker, characterized in that: include, Loop setting module, used to set the test loop; A primary test module is used to perform a test 1 according to the operation process, measure a first parameter, determine whether the test product is successfully disconnected, and if successful, perform a first action, otherwise, perform a second action; according to the test 1, obtain the thermal breaking capacity limit of the high-voltage AC gas circuit breaker; The secondary test module is used to perform the second test according to the operation process based on the thermal breaking capacity limit, measure the first parameter, and determine whether the test product is successfully broken. If successful, execute the third action, otherwise, execute the fourth action; according to the second test, obtain the performance evaluation result of the thermal breaking of the high-voltage AC gas circuit breaker.

9. An electronic device, comprising: Memory and processor; The memory is used to store computer executable instructions, and the processor is used to execute the computer executable instructions. When the computer executable instructions are executed by the processor, the steps of the method for evaluating the thermal breaking performance of a high-voltage AC gas circuit breaker according to any one of claims 1 to 7 are implemented.

10. A computer-readable storage medium storing computer-executable instructions, which, when executed by a processor, implement the steps of the method for evaluating the thermal breaking performance of a high-voltage AC gas circuit breaker according to any one of claims 1 to 7.

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