A pole-mounted circuit breaker overcurrent protection function detection method and detection system

Abstract

This invention relates to the field of equipment testing technology, and discloses a method and system for testing the overcurrent protection function of a pole-mounted circuit breaker. The method includes: acquiring the first-stage overcurrent, second-stage overcurrent, and third-stage overcurrent of the pole-mounted circuit breaker under test, as well as the first protection time, second protection time, and third protection time; converting the first-stage overcurrent into a first secondary voltage value, the second-stage overcurrent into a second secondary voltage value, and the third-stage overcurrent into a third secondary voltage value; converting the first secondary voltage value into a first current value, the second secondary voltage value into a second current value, and the third secondary voltage value into a third current value; and using a relay protection device to test the function of the pole-mounted circuit breaker under test based on the first, second, and third current values, as well as the first, second, and third protection times. This invention solves the problems of high accuracy requirements and inconvenient testing in existing testing methods.

Description

Technical Field

[0001] This invention relates to the field of equipment testing technology, and in particular to a method and system for testing the overcurrent protection function of a pole-mounted circuit breaker. Background Technology

[0002] With the rapid development of power grid automation equipment, the application of automated testing for power grid equipment has become increasingly mature. However, some problems still exist in the automated testing of the protection functions of pole-mounted circuit breakers with deep integration of primary and secondary circuits. Currently, the rated three-phase voltage ratio of pole-mounted circuit breakers with deep integration of primary and secondary circuits is relatively small. If a secondary signal is directly applied to the FTU through a relay protection device, the signal value will be very small, the adjustable range will be relatively narrow, and the accuracy requirements of the relay protection device will be relatively high, making testing inconvenient. Therefore, existing testing methods suffer from high accuracy requirements and inconvenience. Summary of the Invention

[0003] This invention provides a method and system for detecting the overcurrent protection function of pole-mounted circuit breakers, in order to solve the problems of high accuracy requirements and inconvenient detection in existing detection methods.

[0004] To achieve the above objectives, the present invention employs the following technical solution:

[0005] In a first aspect, the present invention provides a method for detecting the overcurrent protection function of a pole-mounted circuit breaker, applied to a primary and secondary deeply integrated pole-mounted circuit breaker function detection system. The system includes: maintenance tools, a relay protection device, and a three-phase voltage-to-current conversion device, comprising:

[0006] The overcurrent stage 1, overcurrent stage 2, and overcurrent stage 3 of the pole-mounted circuit breaker under test are obtained through operation and maintenance tools and devices, as well as the first protection time corresponding to the overcurrent stage 1, the second protection time corresponding to the overcurrent stage 2, and the third protection time corresponding to the overcurrent stage 3.

[0007] Based on the rated transformation ratio of the three-phase current of the pole-mounted circuit breaker under test, the first stage of overcurrent is converted into a first secondary voltage value, the second stage of overcurrent is converted into a second secondary voltage value, and the third stage of overcurrent is converted into a third secondary voltage value.

[0008] The first secondary voltage value is converted into a first current value, the second secondary voltage value is converted into a second current value, and the third secondary voltage value is converted into a third current value according to the current ratio of the three-phase voltage-current conversion device.

[0009] The relay protection device tests the function of the pole-mounted circuit breaker under test based on the first current value, the second current value, the third current value, the first protection time, the second protection time, and the third protection time.

[0010] Optionally, the relay protection device detects the function of the pole-mounted circuit breaker under test based on the first current value, the second current value, and the third current value, as well as the first protection time, the second protection time, and the third protection time, including:

[0011] The first current value and the first protection time are used as the first determination zone, the second current value and the second protection time are used as the second determination zone, and the third current value and the third protection time are used as the third determination zone.

[0012] By inputting the detection current and detection time into the relay protection device, the detection current and detection time are compared with the first determination zone, the second determination zone and the third determination zone respectively, and the fault information of the pole-mounted circuit breaker to be tested is obtained.

[0013] If the result of the size comparison corresponds to the fault information, the overcurrent protection function of the pole-mounted circuit breaker under test is normal; otherwise, the overcurrent protection function of the pole-mounted circuit breaker under test is abnormal.

[0014] Optionally, when the result of the size comparison corresponds to fault information, it includes the following cases:

[0015] Case 1: When the detected current and the detected time are compared with the first determination zone, if the detected current is greater than the first current value and the detected time is greater than the first protection time, the fault information is an overcurrent protection trip warning for the first stage.

[0016] Case 2: When the detected current and the detected time are compared with the second determination zone, if the detected current is greater than the second current value and the detected time is greater than the second protection time, the fault information is an overcurrent protection trip warning for the second stage.

[0017] Case 3: When the detected current and the detected time are compared with the third determination zone, if the detected current is greater than the third current value and the detected time is greater than the third protection time, the fault information is an overcurrent three-stage overcurrent protection trip warning.

[0018] Secondly, embodiments of this application provide a pole-mounted circuit breaker overcurrent protection function detection system, including a memory and a processor.

[0019] Memory is used to store computer programs.

[0020] When a processor executes a program stored in memory, it implements any of the steps of the method described in the first aspect.

[0021] Beneficial effects:

[0022] The overcurrent protection function detection method for pole-mounted circuit breakers provided by this invention converts the acquired overcurrent stage one, overcurrent stage two, and overcurrent stage three currents into first secondary voltage values, second secondary voltage values, and third secondary voltage values, and then converts them again into first current values, second current values, and third current values. The function of the pole-mounted circuit breaker under test can then be detected based on the first current value, second current value, and third current value. This effectively solves the problems of large three-phase voltage and three-phase current ratios and insufficient instrument sampling accuracy in the automated detection of pole-mounted circuit breaker feeders with deep integration of primary and secondary currents. Attached Figure Description

[0023] Figure 1 This is a flowchart of a preferred embodiment of the overcurrent protection function detection method for pole-mounted circuit breakers according to the present invention;

[0024] Figure 2 This is a schematic diagram of the overcurrent protection function detection system for pole-mounted circuit breakers according to a preferred embodiment of the present invention. Detailed Implementation

[0025] The technical solution of the present invention will be clearly and completely described below. 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.

[0026] Unless otherwise defined, the technical or scientific terms used in this invention shall have the ordinary meaning understood by one of ordinary skill in the art to which this invention pertains. The terms "first," "second," and similar terms used in this invention do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Similarly, the terms "an" or "a" and similar terms do not indicate a quantity limitation, but rather indicate the presence of at least one. The terms "connected" or "linked" and similar terms are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. "Up," "down," "left," "right," etc., are used only to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship also changes accordingly.

[0027] Please see Figure 1-2 This application provides a method for detecting the overcurrent protection function of a pole-mounted circuit breaker, applied to a primary and secondary deeply integrated pole-mounted circuit breaker function detection system. The system includes: maintenance tools, a relay protection device, and a three-phase voltage-current conversion device.

[0028] The overcurrent stage 1, overcurrent stage 2, and overcurrent stage 3 of the pole-mounted circuit breaker under test are obtained through operation and maintenance tools and devices, as well as the first protection time corresponding to the overcurrent stage 1, the second protection time corresponding to the overcurrent stage 2, and the third protection time corresponding to the overcurrent stage 3.

[0029] Based on the rated transformation ratio of the three-phase current of the pole-mounted circuit breaker under test, the first stage of overcurrent is converted into a first secondary voltage value, the second stage of overcurrent is converted into a second secondary voltage value, and the third stage of overcurrent is converted into a third secondary voltage value.

[0030] The first secondary voltage value is converted into a first current value, the second secondary voltage value is converted into a second current value, and the third secondary voltage value is converted into a third current value according to the current ratio of the three-phase voltage-current conversion device.

[0031] The relay protection device tests the function of the pole-mounted circuit breaker under test based on the first current value, the second current value, the third current value, the first protection time, the second protection time, and the third protection time.

[0032] In the above embodiments, by converting the acquired overcurrent stage one, overcurrent stage two, and overcurrent stage three currents into first secondary voltage values, second secondary voltage values, and third secondary voltage values, and then converting them again into first current values, second current values, and third current values, the function of the pole-mounted circuit breaker to be tested can be detected based on the first current value, the second current value, and the third current value. This effectively solves the problems of large three-phase voltage and three-phase current ratios and insufficient instrument sampling accuracy during the automated detection of pole-mounted circuit breaker feeders with deep integration of primary and secondary currents.

[0033] Optionally, the relay protection device detects the function of the pole-mounted circuit breaker under test based on the first current value, the second current value, and the third current value, as well as the first protection time, the second protection time, and the third protection time, including:

[0034] The first current value and the first protection time are used as the first determination zone, the second current value and the second protection time are used as the second determination zone, and the third current value and the third protection time are used as the third determination zone.

[0035] By inputting the detection current and detection time into the relay protection device, the detection current and detection time are compared with the first determination zone, the second determination zone and the third determination zone respectively, and the fault information of the pole-mounted circuit breaker to be tested is obtained.

[0036] If the result of the size comparison corresponds to the fault information, the overcurrent protection function of the pole-mounted circuit breaker under test is normal; otherwise, the overcurrent protection function of the pole-mounted circuit breaker under test is abnormal.

[0037] Optionally, when the result of the size comparison corresponds to fault information, it includes the following cases:

[0038] Case 1: When the detected current and the detected time are compared with the first determination zone, if the detected current is greater than the first current value and the detected time is greater than the first protection time, the fault information is an overcurrent protection trip warning for the first stage.

[0039] Case 2: When the detected current and the detected time are compared with the second determination zone, if the detected current is greater than the second current value and the detected time is greater than the second protection time, the fault information is an overcurrent protection trip warning for the second stage.

[0040] Case 3: When the detected current and the detected time are compared with the third determination zone, if the detected current is greater than the third current value and the detected time is greater than the third protection time, the fault information is an overcurrent three-stage overcurrent protection trip warning.

[0041] The specific detection process in this embodiment is as follows:

[0042] (1) Set the overcurrent stage I setting value of the terminal equipment to 600A and the protection action delay time to 0s, the overcurrent stage II setting value to 480A and the protection action delay time to 1s, and the overcurrent stage III setting value to 240A and the protection action delay time to 3s.

[0043] (2) The rated three-phase current ratio of the primary and secondary deep integration circuit breaker is 600A / 1V. Then, through conversion, the overcurrent I, II and III setting values ​​are converted to 1V, 0.8V and 0.4V respectively.

[0044] (3) The current ratio of the three-phase voltage-current conversion device is 1A / 1V. The secondary voltage values ​​of the overcurrent section I, section II and section III are converted into current values ​​of 1A, 0.8A and 0.4A respectively.

[0045] (4) Based on the conversion results, in order to check whether the overcurrent protection of stage I meets the requirements, apply IA=IB=IC=0.95 for 0.05 seconds in the relay protection tester and check whether the circuit breaker operates and whether it uploads a fault alarm signal. If the switch does not operate and the terminal has no alarm, it indicates that the switch is operating normally. Next, apply IA=IB=IC=1.05 for 0.05 seconds in the relay protection tester and check whether the circuit breaker operates and whether it uploads a fault alarm signal. If the switch trips and the terminal reports a trip warning for the overcurrent protection of stage I of phases A, B, and C and the total overcurrent protection of short circuit fault, it indicates that the switch is operating normally.

[0046] (5) Similarly, the overcurrent sections II and III are tested in the same way.

[0047] This application also provides a pole-mounted circuit breaker overcurrent protection function detection system, including a memory and a processor.

[0048] Memory is used to store computer programs.

[0049] The processor, when executing a program stored in memory, implements any of the steps described in the method for detecting the overcurrent protection function of a pole-mounted circuit breaker.

[0050] The above-described pole-mounted circuit breaker overcurrent protection function detection system can implement all embodiments of the above-described pole-mounted circuit breaker overcurrent protection function detection method and achieve the same beneficial effects, which will not be elaborated here.

[0051] The preferred embodiments of the present invention have been described in detail above. It should be understood that those skilled in the art can make numerous modifications and variations based on the concept of the present invention without creative effort. Therefore, all technical solutions that can be obtained by those skilled in the art based on the concept of the present invention through logical analysis, reasoning, or limited experimentation on the basis of existing technology should be within the scope of protection defined by the claims.

Claims

1. A method for detecting overcurrent protection function of a pole-mounted circuit breaker, applied to a primary and secondary deeply integrated pole-mounted circuit breaker function detection system, the system comprising: Maintenance tools, relay protection devices, and three-phase voltage-current conversion devices, characterized in that the method includes: The overcurrent stage 1, overcurrent stage 2, and overcurrent stage 3 of the pole-mounted circuit breaker under test are obtained through operation and maintenance tools and devices, as well as the first protection time corresponding to the overcurrent stage 1, the second protection time corresponding to the overcurrent stage 2, and the third protection time corresponding to the overcurrent stage 3. Based on the rated transformation ratio of the three-phase current of the pole-mounted circuit breaker under test, the first stage of overcurrent is converted into a first secondary voltage value, the second stage of overcurrent is converted into a second secondary voltage value, and the third stage of overcurrent is converted into a third secondary voltage value. The first secondary voltage value is converted into a first current value, the second secondary voltage value is converted into a second current value, and the third secondary voltage value is converted into a third current value according to the current ratio of the three-phase voltage-current conversion device. The relay protection device detects the function of the pole-mounted circuit breaker under test based on the first current value, the second current value, the third current value, the first protection time, the second protection time, and the third protection time. The first current value and the first protection time are used as the first determination zone, the second current value and the second protection time are used as the second determination zone, and the third current value and the third protection time are used as the third determination zone. By inputting the detection current and detection time into the relay protection device, the detection current and detection time are compared with the first judgment zone, the second judgment zone and the third judgment zone respectively, and the fault information of the pole-mounted circuit breaker to be tested is obtained. If the result of the size comparison corresponds to the fault information, the overcurrent protection function of the pole-mounted circuit breaker under test is normal; otherwise, the overcurrent protection function of the pole-mounted circuit breaker under test is abnormal.

2. The pole-mounted circuit breaker overcurrent protection function detection method of claim 1, wherein When the result of the size comparison corresponds to the fault information, it includes the following situations: Case 1: When the detected current and the detected time are compared with the first determination zone, if the detected current is greater than the first current value and the detected time is greater than the first protection time, and the fault information is an overcurrent protection trip warning for the first stage; Case 2: When the detected current and the detected time are compared with the second determination zone, if the detected current is greater than the second current value and the detected time is greater than the second protection time, and the fault information is the overcurrent protection trip warning for the second stage; Case 3: When the detected current and the detected time are compared with the third determination zone, if the detected current is greater than the third current value and the detected time is greater than the third protection time, the fault information is an overcurrent three-stage overcurrent protection trip warning.

3. A pole-mounted circuit breaker overcurrent protection function detection system, characterized by, Including memory and processor; Memory, used to store computer programs; A processor, when executing a program stored in memory, implements the steps of the method described in any one of claims 1-2.

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