CN-121763002-B - Power transmission line fault simulation and simulation test method and system

CN121763002BCN 121763002 BCN121763002 BCN 121763002BCN-121763002-B

Abstract

A power transmission line fault simulation and simulation test method and system establish a transient simulation model of an actual power transmission line, simulate and calculate wave speed, carry out simulation test on the test line, output a power frequency normal current, inject a lightning stroke pulse at one peak value of the power frequency normal current, then output an insulator string flashover discharge current, calculate the duration of the insulator string flashover discharge current according to the lightning stroke fault current set during simulation, if the test is normal, acquire two fault detection devices to capture the wave head time extracted by the lightning current waveform, calculate two corresponding positioning errors by combining the wave speed calculated by simulation, if the positioning errors exceed the set error threshold, indicate that the fault detection device is not qualified, otherwise, use the fault detection device with qualified detection to carry out fault test. The invention can efficiently develop the detection test of the power transmission line fault positioning device.

Inventors

LI JIAN
LI LIANLIAN
ZHENG LEI
JIANG YI
XU HENG

Assignees

国网电力科学研究院武汉南瑞有限责任公司

Dates

Publication Date: 20260508
Application Date: 20260228

Claims (11)

1. The power transmission line fault simulation and simulation test method is characterized by comprising the following steps of: Selecting two towers from the actual power transmission line as an initial tower and a final tower respectively, and selecting one tower from all towers between the initial tower and the final tower as a fault tower; Establishing a transient simulation model of an actual power transmission line, injecting set lightning fault current into a fault tower position in the simulation model, and installing current sensors at the position of an initial tower and a position of a final tower in the simulation model; Performing simulation test on a test line, installing two fault monitoring devices on an initial tower and a final tower of the test line, wherein a fault source is arranged at the position of the fault tower, outputting the fault source, outputting power frequency normal current, injecting lightning stroke pulse at one peak value of the power frequency normal current, and then outputting insulator string flashover discharge current, wherein the duration time of the insulator string flashover discharge current is calculated according to lightning stroke fault current set during simulation; If the test line is not tripped in the set time range after the lightning stroke pulse is injected, the threshold value of the tripping trigger of the fault detection device on the test line is regulated according to the amplitude range of different fault types, the steps are repeated from the fault source, otherwise, the test is normal, the time of capturing the wave heads extracted by the lightning current waveforms by the two fault detection devices is obtained, the corresponding two positioning errors are calculated by combining the wave speeds calculated by simulation, if the positioning errors exceed the set error threshold value, the fault detection device is failed, otherwise, the fault detection device is qualified, and the fault detection device with qualified detection is used for fault test.
2. The transmission line fault simulation and emulation test method according to claim 1, wherein: The method comprises the steps of establishing a transient simulation model of an actual power transmission line, injecting set lightning stroke fault current into a fault tower position in the simulation model, and specifically comprises the following steps: The transient simulation model is a frequency-dependent electromagnetic transient model, adopts a dual-power topological structure, changes active power and load current to actual active power and load current by adjusting a power angle, adopts corresponding parameters of an actual power transmission line, namely wire diameter, split beam, wire height, ground wire height and phase interval, and injects set lightning stroke fault current after the power transmission line stably operates.
3. The transmission line fault simulation and emulation test method according to claim 2, wherein: the lightning stroke fault current specifically comprises the following components: and carrying out weighted summation on 8/20 mu s lightning current and 10/350 mu s lightning current according to set weights to obtain set lightning fault current.
4. The transmission line fault simulation and emulation test method according to claim 1, wherein: The wave speed is calculated by the time difference of the wave head time detected by the two current sensors, and is specifically as follows: And acquiring wave head moments acquired by the two current sensors, acquiring the position of the fault tower taking the midpoint of the power transmission line as a datum point, and dividing the position of the fault tower with the datum point by the difference of the wave head moments acquired by the two current sensors by using the position of the fault tower with the datum point which is 2 times as large as the datum point to obtain the wave speed.
5. A transmission line fault simulation and emulation test method according to claim 3, wherein: the fault source outputs, specifically: The duration of the power frequency normal current output by the fault source is in the range from the cycle duration of one power frequency normal current to the cycle duration of two power frequency normal currents; the duration of the flashover discharge current of the insulator string is that the peak time of the lightning current of 10/350 mu s is subtracted by the peak time of the lightning current of 8/20 mu s, the cycle time of the power frequency normal current is added, the calculated result is multiplied by the difference between the weight of the lightning current of 10/350 mu s and the weight of the lightning current of 8/20 mu s, and the cycle time of the power frequency normal current is added.
6. The power transmission line fault simulation and emulation test method according to claim 5, wherein: the threshold value of the fault detection device on the test line is adjusted according to the amplitude ranges of different fault types, and specifically comprises the following steps: The set time range is between the cycle time of one power frequency normal current and the cycle time of two power frequency normal currents; Fault types include high resistance faults, low resistance faults, and metallic ground faults; The amplitude range of the high-resistance fault is from a first threshold value to a second threshold value, and the amplitude range of the low-resistance fault is from the second threshold value to a third threshold value; the threshold value of the metallic ground fault is more than a third threshold value; If the cycle time passing through the two power frequency normal currents after the lightning stroke pulse is injected is still not tripped, the threshold value of the fault detection device for triggering the tripping is reduced, if the current threshold value is larger than a third threshold value, the current threshold value is adjusted to the third threshold value, if the current threshold value is larger than the second threshold value and smaller than or equal to the third threshold value, the current threshold value is adjusted to the second threshold value, otherwise, the current threshold value is adjusted to the first threshold value; If the cycle time of the power frequency normal current is not reached after the lightning stroke pulse is injected, the threshold value of the fault detection device for triggering the tripping is increased, if the current threshold value is smaller than the first threshold value, the current threshold value is adjusted to the first threshold value, if the current threshold value is larger than or equal to the first threshold value and smaller than the second threshold value, the current threshold value is adjusted to the second threshold value, and otherwise, the current threshold value is adjusted to the third threshold value.
7. The power transmission line fault simulation and emulation test method of claim 6, wherein: if the amplitude of the current insulator string flashover discharge current is in the amplitude range of the high-resistance fault, superposing set background noise on the insulator string flashover discharge current, wherein the set background noise is a hidden danger current signal or a corona current signal with set frequency and amplitude.
8. The transmission line fault simulation and emulation test method according to claim 1, wherein: the wave speed calculated by combining simulation calculates two corresponding positioning errors, specifically: acquiring tower numbers of an initial tower, a fault tower and a termination tower on an actual power transmission line, and subtracting a product of a wave head time extracted by capturing a lightning current waveform by a fault detection device positioned on the initial tower and a wave speed calculated by simulation from a span of the initial tower number subtracted by the tower number multiplied by the tower number from the initial tower number to be used as a first error; The tower number of the fault is subtracted by the tower number of the final tower, the tower number multiplied by the tower number is subtracted by a fault detection device positioned on the final tower, and the product of the wave head time extracted by the lightning current waveform and the wave speed calculated by simulation is captured as a second error.
9. A power transmission line fault simulation and simulation test system based on the method of any one of claims 1-8, comprising a test line construction module, a simulation wave speed calculation module, a simulation test module and a test module, and being characterized in that: The test line construction module is used for selecting two towers from the actual power transmission line as an initial tower and a final tower respectively, and selecting one tower from all towers between the initial tower and the final tower as a fault tower; The simulation wave speed calculation module is used for establishing a transient simulation model of the actual power transmission line, injecting set lightning stroke fault current into the position of a fault tower in the simulation model, and installing current sensors at the position of an initial tower and a terminal tower in the simulation model; The simulation test module is used for carrying out simulation test on a test circuit, installing two fault monitoring devices on an initial tower and a final tower of the test circuit, setting a fault source at the position of the fault tower, outputting a power frequency normal current, injecting a lightning stroke pulse at one peak value of the power frequency normal current, and then outputting an insulator string flashover discharge current, wherein the duration time of the insulator string flashover discharge current is calculated according to the lightning stroke fault current set during simulation; The test module is used for adjusting the threshold value of the tripping trigger of the fault detection device on the test circuit according to the amplitude range of different fault types if the test circuit is not tripped in the set time range after the lightning stroke pulse is injected, repeating the steps from the fault source, otherwise, indicating that the test is normal, acquiring the wave head time extracted by the two fault detection devices for capturing the lightning current waveform, calculating the corresponding two positioning errors by combining the wave speed calculated by simulation, and indicating that the fault detection device is not qualified if the positioning error exceeds the set error threshold value, otherwise, using the fault detection device which is qualified for detection to perform fault test.
10. An apparatus comprising a memory and a processor, the memory storing a computer program, characterized in that the processor implements the steps of the method of any one of claims 1 to 8 when the computer program is executed.
11. A computer readable storage medium having stored thereon a computer program, characterized in that the computer program when executed by a processor realizes the steps of the method according to any of claims 1 to 8.

Description

Power transmission line fault simulation and simulation test method and system Technical Field The invention belongs to the technical field of high voltage of power systems, and particularly relates to a power transmission line fault simulation and simulation test method and system. Background The traditional power system fault test is generally completed by adopting a true test, namely, a true distribution network overhead or cable true line is erected by using real power equipment, various defects or faults are simulated, and a verification test carried out in a field real environment is reproduced. The true test can reproduce the real operation and fault scene in a short period, record complete test phenomenon and data, does not influence the power supply of users, is only suitable for distribution lines, but cannot be applied to the transmission lines due to the fact that the real equipment has high cost and large site. At present, the fault test of the power transmission line is mainly realized based on software simulation and laboratory simulation modes. Based on EMTDC electromagnetic transient simulation software, a transmission line distribution parameter model is built, transient characteristics of different voltage classes and capacities can be simulated, power electronic devices exist due to power supply and load, nonlinear characteristics are achieved, an actual model is a simple linear combination, frequency domain influence is not considered, and the method has certain subjectivity and a certain difference from a real power grid model. The high-voltage impact current source is built in a high-voltage laboratory, the high-voltage impact test can simulate lightning strike under ideal conditions approximately, the high-voltage pulse is injected into the test line, the test line is a very short cable or overhead conductor, parts such as an actual lightning arrester and an insulator are not considered, the high-frequency response characteristic is not different from that of an actual power system, but the test distance is short, and the outdoor long-distance power transmission line is not applicable. Along with the fact that the fault monitoring device is applied to the power transmission line in a large number, higher requirements are put forward on the monitoring precision and the stable and reliable operation performance of the fault monitoring device. At present, fault monitoring device manufacturers are numerous, domestic partial metering detection units and network province companies develop network access detection work of environmental test types, adaptability of equipment to field application environments is guaranteed to a certain extent, but effective testing means and methods are lacked in core function verification aspects such as fault current accuracy, traveling wave current accuracy, fault positioning accuracy and the like, and technical vacuum exists in testing depth and breadth. Disclosure of Invention In order to solve the defects in the prior art, the invention provides a power transmission line fault simulation and simulation test method and system. The invention adopts the following technical scheme. The first aspect of the invention provides a power transmission line fault simulation and simulation test method, which comprises the following steps: Selecting two towers from the actual power transmission line as an initial tower and a final tower respectively, and selecting one tower from all towers between the initial tower and the final tower as a fault tower; Establishing a transient simulation model of an actual power transmission line, injecting set lightning fault current into a fault tower position in the simulation model, and installing current sensors at the position of an initial tower and a position of a final tower in the simulation model; Performing simulation test on a test line, installing two fault monitoring devices on an initial tower and a final tower of the test line, wherein a fault source is arranged at the position of the fault tower, outputting the fault source, outputting power frequency normal current, injecting lightning stroke pulse at one peak value of the power frequency normal current, and then outputting insulator string flashover discharge current, wherein the duration time of the insulator string flashover discharge current is calculated according to lightning stroke fault current set during simulation; If the test line is not tripped in the set time range after the lightning stroke pulse is injected, the threshold value of the tripping trigger of the fault detection device on the test line is regulated according to the amplitude range of different fault types, the steps are repeated from the fault source, otherwise, the test is normal, the time of capturing the wave heads extracted by the lightning current waveforms by the two fault detection devices is obtained, the corresponding two positioning errors are calculated by combining the wave spe