A two-way wave device for fault location in overhead power lines based on FPGA

Abstract

This utility model relates to recorders of emergency events and processes in electrical networks, specifically to fault location devices on overhead power lines (OPLs). The technical result consists of improving the fault location accuracy by taking into account the actual lengths of the OPL overhead sections. To this end, a unit for determining the actual wave propagation velocity in the damaged section and a wave fault location unit are connected via their additional inputs to the output of a unit for determining the actual length of the OPL overhead sections, the input of which is connected to a wire temperature sensor at the device's installation location.

Description

[0001] The utility model relates to recorders of emergency events and processes in electrical networks, namely to devices for determining the location of damage on cable-overhead power lines (COL).

[0002] The device is intended to be implemented using high-performance Xilinx Virtex-4 (e.g., XC4VSX35, XC4VFX40, XC4VSX55), Virtex-5 (e.g., XC5VLX30, XC5VSX240T), Virtex-6 (e.g., XC6VLX130T, XC6VSX475T) and Virtex-7 (e.g., XC7A200T, XC7K480T) FPGAs.

[0003] Devices implementing a method for two-way wave fault location on a power transmission line (Lei Wang, Hui Liu, Le Van Dai and Yuwei Liu. Novel Method for Identifying Fault Location of Mixed Lines / Energies 2018 (11). - doi:10.3390 / en11061529) are known from the existing state of the art. According to this method, the fault location is determined based on measurements by two devices installed on both sides of the power transmission line. In this case, each device measures its own phase currents of the power transmission line synchronously with the other device, converts them into a controlled signal, and records the arrival moment of the primary wave based on this signal. The arrival moment of the primary wave is received from the other device via a transceiver, and the duration of the interval between the arrival moments of the primary waves to the devices is determined.After this, each section of the waterline is sequentially considered damaged, and the distance to the damage location is calculated using the aforementioned interval duration and the wave propagation velocity in each section as the propagation velocity in the corresponding lossless line. If the coordinate of the calculated damage location lies within the conditionally damaged section, then this location is considered the damage location on the waterline.

[0004] The accepted assumption that in sections the wave propagates at the speed of the line without losses leads to an increase in the error in determining the distance to the fault location.

[0005] The specified drawback is eliminated in the wave fault location device based on the SHEE 23X 092X cabinet, which implements a method for two-sided wave fault location on a cable-overhead power transmission line (Patent for Invention No. 2774049, Russian Federation, IPC G01R 31 / 08. Method for two-sided wave fault location on a cable-overhead power transmission line: No. 2021124803: declared 08 / 20 / 2021: published 06 / 14 / 2022 / Fedorov A. O., Petrov V. S., Antonov V. I., Naumov V. A., Doni N. A.; patent holder: Limited Liability Company Scientific and Production Enterprise "EKRA"). According to the method, in order to increase the accuracy of fault location, the actual wave propagation velocity in the damaged section is determined.For this purpose, the calculated durations of the intervals between the arrival times of primary waves at the devices are sequentially determined, assuming the location of the fault locations at the boundaries of the overhead line sections. The damaged section is then determined by the location of the duration of the interval between the arrival times of primary waves at the devices during a fault on the overhead line in the sequence of calculated interval durations. The wave propagation velocity in the damaged section is defined as the speed at which the wave travels a distance equal to twice the length of the damaged section, in a time equal to the sum of the time counter readings of its own device and the other device. In each device, the time counter is started at the arrival of the primary wave and stopped at the arrival of the first wave reflected from the fault location. The sum of the time counter readings will then equal the time it takes for the wave to travel twice the length of the damaged section.In this case, the distance to the damage site is determined as the sum of the lengths of the undamaged sections of the cable line on the device side and the part of the damaged section that the wave travels through in a time equal to half the reading of its time counter.

[0006] This method uses preset cable line section lengths. However, the overhead section lengths vary from the actual lengths due to changes in cable temperature. This reduces the accuracy of determining the actual wave propagation velocity in the overhead sections and the distance to the fault.

[0007] The specified device is the closest to the declared technical solution and is accepted as a prototype.

[0008] The technical result of the utility model is to increase the accuracy of localization of the damage location by taking into account the actual lengths of the overhead sections of the cable line.

[0009] The technical result is achieved by the claimed device for two-sided wave detection of the location of a fault in a cable overhead line based on an FPGA, including a synchronous measurement generation unit, to the inputs of which high-frequency current sensors of the phases of one of the sides of the cable overhead line and a receiver of synchronizing signals of a satellite navigation system are connected, and the output is connected to the input of the controlled signal generation unit, to the output of which the input of the unit for recording the moment of arrival of the primary wave and the input of the unit for recording the moment of arrival of the first wave reflected from the fault location are connected, an interval duration determination unit, one input of which is connected to the output of the unit for recording the moment of arrival of the primary wave, and the other to the output of the transceiver, and the output is connected to the input of the unit for determining the damaged section, first and second orthogonal component filters, to the inputs of which low-frequency current and voltage sensors of the phases of the cable overhead line of the power transmission system are connected, respectively,and to the outputs - the inputs of the block for determining the location of the fault according to the emergency mode parameters, the output of which is connected to the additional input of the block for recording the moment of arrival of the first wave reflected from the fault location, a time counter, one input of which is connected to the output of the block for recording the moment of arrival of the primary wave, the other - to the output of the block for recording the moment of arrival of the first wave reflected from the fault location, and the output is connected to the input of the block for determining the actual velocity of wave propagation in the faulty section and the input of the block for wave determination of the fault location, to the other inputs of the block for determining the actual velocity of wave propagation in the faulty section the output of the block for determining the faulty section and the additional output of the transceiver, the inputs of which are connected to the output of the block for recording the moment of arrival of the primary wave and the output of the time counter, the block for wave determination of the fault location,The other input of which is connected to the output of the damaged section detection unit by introducing new elements and establishing new connections between them. The new connections are as follows. The unit for determining the actual wave propagation velocity in the damaged section and the wave fault location unit are connected with their additional inputs to the output of the unit for determining the actual length of the overhead cable line sections, to the input of which the wire temperature sensor is connected at the device installation location.

[0010] The figure illustrates the structural diagram of the claimed device.

[0011] In the claimed device, high-frequency current sensors of the phases of one of the sides of the KVL (HFCS) are connected to the inputs of the block 1 for generating synchronous measurements. А , DTVCH В and DTVCH С) and a receiver of synchronizing signals of the satellite navigation system 2, and the input of the block 3 for generating the controlled signal is connected to the output. The output of the said block 3 for generating the controlled signal is connected to the input of the block 4 for recording the moment of arrival of the primary wave and the input of the block 5 for recording the moment of arrival of the first wave reflected from the fault location. The output of block 4 is connected to the input of the block 6 for determining the interval duration, the other input of which is connected to the output of the transceiver 7, through which the value of the moment of arrival of the primary wave is received from the device on the opposite side. In this case, the output of the block 6 for determining the interval duration is connected to the input of the block 8 for determining the damaged section. At the same time, the claimed device uses the first (block 9) and second (block 10) orthogonal component filters, to the inputs of which low-frequency current sensors (LFCS) are connected А , DTNC В and DTNC С ) and voltage (DNNC А, DNNC В and DNNNCH С) phases of the KVL, respectively, and to the outputs - the inputs of block 11 for determining the fault location based on the emergency mode parameters, the output of which is connected to the additional input of block 5 for recording the arrival moment of the first wave reflected from the fault location. The outputs of the said blocks 4 and 5 are connected to the inputs of time counter 12, the output of which is connected to the input of block 13 for determining the actual wave propagation velocity in the faulty section and the input of block 15 for wave fault location. The output of block 8 for determining the faulty section and the additional output of transceiver 7, through which the reading of its time counter is received from the device on the opposite side of the KVL, are connected to the other inputs of block 13 for determining the actual wave propagation velocity in the faulty section. To ensure operation of the device on the opposite side of the KVL, the value of the arrival moment of the primary wave from the output of block 4 and the reading of time counter 12 are received at the inputs of transceiver 7.At the same time, the output of the damaged section determination unit 8 is connected to another input of the wave fault location unit 15. Furthermore, the actual wave propagation velocity determination unit 13 for the damaged section and the wave fault location unit 15 are connected via their additional inputs to the output of the actual length determination unit 14 for the overhead cable section, to the input of which the DT wire temperature sensor is connected at the device installation location.

[0012] Due to the fact that high-frequency current sensors of the phases of the KVL (HFC А , DTVCH В and DTVCH С ) generate 1 million samples per second, and low-frequency current sensors (LFCS) А , DTNC В and DTNC С ) and voltage (DNNC А , DNNC В and DNNC С ) phases of the KVL - 2000 samples per second, and the claimed device operates in real time, blocks 1, 3 - 6, 8 - 15 are implemented on the basis of FPGA 16.

[0013] The distance to the fault location is determined as follows. Unit 1 for generating synchronous measurements receives digital readings of the phase currents of the KVL from high-frequency current sensors (HFCS). А , DTVCH В and DTVCH Сand assigns them time stamps based on data from the receiver of synchronizing signals of satellite navigation system 2. Unit 3, which generates a controlled signal based on the aforementioned synchronous measurements, calculates the signal of the interphase wave channel using Clarke's rule and suppresses the fundamental harmonic in it with a digital high-pass filter. From the output of unit 3, the controlled signal is fed to the input of unit 4, which records the arrival moment of the primary wave, and to the input of unit 5, which records the arrival moment of the first wave reflected from the fault location. The arrival moment of the wave in these units is recorded by comparing the absolute value of the controlled signal with a certain threshold.In this case, to recognize the first wave reflected from the fault location in block 5, as in the prototype, the distance to the fault location is used, determined by block 11 according to the emergency mode parameters, namely, according to the complex values ​​of the currents and voltages of the phases arriving at the input of block 11 from the first (block 9) and second (block 10) orthogonal component filters connected to low-frequency current sensors (LFCS). А , DTNC В and DTNC С ) and voltage (DNNC А , DNNC В and DNNC С ) phases of the KVL. The operating principle of block 11 for determining the fault location based on emergency mode parameters is well known and is based on finding the minimum of the target function of reactive power.

[0014] In block 6, the duration of the interval between the moment of arrival of the primary wave, recorded in block 4, and the moment of arrival of the primary wave to the device on the opposite side of the KVL, the value of which comes from the transceiver 7, is calculated. In this case, in block 8, as well as in the prototype, the damaged section is determined on the basis of the mentioned duration of the interval.

[0015] The actual wave propagation velocity in the damaged section is determined in block 13 as the speed at which the wave travels a distance equal to twice the actual length of the damaged section, in a time equal to the sum of the time counter readings of its own and the other device. Time counter 12 is started at the moment of arrival of the primary wave and stopped at the moment of arrival of the first wave reflected from the fault location. For this purpose, its inputs are connected to the output of block 4 and block 5. The time counter reading of the device on the opposite side of the KVL is received from transceiver 7.

[0016] If the damaged section is air-borne, then block 13 receives its actual length from block 14, which is determined in a well-known manner (Idelchik V.I. Electrical systems and networks. Moscow: Energoatomizdat, 1989. - 592 p.) based on measurements from the DT wire temperature sensor:

[0017]

[0018] where And - the length of the damaged overhead section and the temperature of the wire at the installation site of the device when it was put into operation;

[0019] - coefficient of linear thermal expansion;

[0020] - the actual temperature of the wire at the installation location of the device.

[0021] Along with this, block 14 similarly determines the actual lengths of the remaining overhead sections. The actual lengths of the cable sections are assumed to be equal to the predetermined lengths, since the cable sections are laid underground and their length is practically independent of the conductor temperature.

[0022] Block 15 determines the distance to the damage location as the sum of the actual lengths of the undamaged sections of the cable line from the device side and the part of the damaged section that the wave travels over a time equal to half the reading of its time counter.

[0023] Thus, by determining the actual length of the overhead sections of the cable line based on measurements from the wire temperature sensor, it is possible to increase the accuracy of localizing the damage location by the device.

Claims

A device for two-way wave fault location of an overhead cable power transmission line based on an FPGA, comprising a synchronous measurement generation unit, to the inputs of which high-frequency current sensors of the phases of one of the sides of the overhead cable power transmission line and a receiver of synchronizing signals of a satellite navigation system are connected, and the output is connected to the input of a controlled signal generation unit, to the output of which the input of the unit for recording the moment of arrival of the primary wave and the input of the unit for recording the moment of arrival of the first wave reflected from the fault location are connected, an interval duration determination unit, one input of which is connected to the output of the unit for recording the moment of arrival of the primary wave, and the other to the output of the transceiver, and the output is connected to the input of the unit for detecting the damaged section, first and second orthogonal component filters, to the inputs of which low-frequency current and voltage sensors of the phases of the overhead cable power transmission line are connected,accordingly, and to the outputs - the inputs of the block for determining the location of the fault according to the emergency mode parameters, the output of which is connected to the additional input of the block for recording the moment of arrival of the first wave reflected from the fault location, a time counter, one input of which is connected to the output of the block for recording the moment of arrival of the primary wave, the other - to the output of the block for recording the moment of arrival of the first wave reflected from the fault location, and the output is connected to the input of the block for determining the actual wave propagation speed in the faulty section and the input of the block for wave determination of the fault location, the output of the block for determining the faulty section and the additional output of the transceiver, the inputs of which are connected to the output of the block for recording the moment of arrival of the primary wave and the output of the time counter, the block for wave determination of the fault location, are connected to the other inputs of the block for determining the actual wave propagation speed in the faulty section.the other input of which is connected to the output of the unit for determining the damaged section, characterized in that the unit for determining the actual wave propagation speed in the damaged section and the unit for wave determination of the location of the damage are connected with their additional inputs to the output of the unit for determining the actual length of the overhead sections of the cable-overhead power transmission line, to the input of which a wire temperature sensor is connected at the location where the device is installed.

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