A fault location method based on primary and secondary integrated pole-mounted circuit breaker

Abstract

The present invention discloses a fault ranging method based on a primary and secondary integrated pole-mounted circuit breaker, which relates to the field of distribution network fault judgment, and includes the following steps: selecting a pole-mounted circuit breaker as a master device among the pole-mounted circuit breakers of the transmission line, and the remaining pole-mounted circuit breakers as slave devices; the master device is configured as a pole-mounted circuit breaker with the best 4G / 5G signal or a pole-mounted circuit breaker closest to the main station; optical fibers are connected between the pole-mounted circuit breakers to form a self-organizing network; and the pole-mounted circuit breakers are synchronized through optical fibers. When the present invention is applied, the equipment on the entire line is cascaded through optical fiber communication, providing ultra-high time accuracy, increasing the accuracy of fault ranging, eliminating network security issues through self-organizing networking, and being unaffected by the network and region. Active fault detection and fault ranging are achieved by actively sending pulse signals.

Description

Technical Field

[0001] The invention relates to the field of distribution network fault judgment, and in particular to a fault distance measurement method based on a primary-secondary integrated pole-mounted circuit breaker. Background Art

[0002] In the prior art, fault distance measurement of distribution networks is basically achieved through time synchronization through GPS timing, by continuously collecting line information to capture the first wave of the fault, and judging the fault distance by the time difference when the first wave reaches different devices. However, if the weather is bad or the fault rate is higher on rainy days, there will be a large deviation in timing, and the fault distance error will be large. The GPS timing method is more affected by weather and environment. In the prior art, only by accurately capturing the first wave of the fault can the fault distance be judged. However, the grid structure of the medium-voltage distribution network is complex. When a high-resistance grounding fault occurs, the fault characteristics of the line will be very small, and the equipment will often make misjudgments or miss judgments. Summary of the invention

[0003] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a fault ranging method based on a primary and secondary integrated pole-mounted circuit breaker. When used, the equipment on the entire line is cascaded through optical fiber communication, providing ultra-high time accuracy, increasing the accuracy of fault ranging, eliminating network security problems through self-organizing networking, and is not affected by the network and region. Active fault detection and fault ranging are achieved by actively sending pulse signals.

[0004] The purpose of the present invention is mainly achieved through the following technical solutions:

[0005] A fault location method based on a primary and secondary integrated pole-mounted circuit breaker comprises the following steps:

[0006] A pole-mounted circuit breaker is selected from among the pole-mounted circuit breakers of the transmission line as a master device, and the remaining pole-mounted circuit breakers are selected as slave devices; the master device is configured as a pole-mounted circuit breaker with the best 4G / 5G signal or a pole-mounted circuit breaker closest to the master station;

[0007] Optical fibers are connected between the circuit breakers on each pole to form a self-network;

[0008] The circuit breakers on each pole are timed by optical fiber;

[0009] When there is no fault in the power transmission line, the master device controls the slave device to send the first AC signal and the first pulse signal in sequence, and the master device and the slave device that has not sent the first AC signal and the first pulse signal at the current moment respectively collect and record the characteristic waveforms of the first AC signal and the first pulse signal sent by different slave devices;

[0010] Setting a signal sending interval time, the master device controls the slave devices to send the second AC signal in sequence after each interval time, the master device and the slave devices that have not sent the second AC signal at the current moment respectively collect the second AC signals sent by different slave devices, and compare them with the characteristic waveforms of the first AC signals collected by the master device and the slave devices when the transmission line is fault-free, to determine whether a fault occurs in the transmission line; the second AC signal is the same AC signal as the first AC signal;

[0011] If a transmission line fails, the device inside and outside the area is selected as the first device, and the two devices outside the area closest to the fault point are selected as the second and third devices;

[0012] Calculate the distances between the second device and the third device and the fault point based on the impedance method and the standing wave method respectively;

[0013] The distances from the second device and the third device to the fault point calculated based on the impedance method and the standing wave method are collected, and all fault points are topologically plotted on the line topology map. The second device or the third device is used as a reference point to eliminate the fault points within the area. The irrelevant points outside the area are calculated based on the LOF algorithm and eliminated. The distances of the remaining fault points are averaged as the final fault distance.

[0014] In the present application, the time synchronization between the pole-mounted circuit breakers on the transmission line is carried out through optical fiber, which is not affected by the environment, and more accurate time synchronization information can be obtained by adding the propagation delay of light; in the present application, an optical fiber self-organized network is used between the pole-mounted circuit breakers, and the data collected by the pole-mounted circuit breakers are transmitted through optical fiber, which basically eliminates network security problems, reduces the load of the main station, and is basically not affected by the network and region. In the present application, different from the prior art that performs fault judgment by passively detecting the first wave of the fault, the fault detection of the present application adopts an active detection method, and determines whether the transmission line has a fault by actively sending an AC signal to the transmission line by the pole-mounted circuit breaker. In the present application, when there is no fault, the master device controls each slave device to send a first AC signal to the transmission line in turn, and the master device and the slave device that has not sent the first AC signal receive the first AC signal sent from each slave device as a reference signal; at regular intervals, the master device controls each slave device to send a second AC signal in turn, and the master device and the slave device that has not sent the second AC signal receive the second AC signal sent from each slave device as a comparison signal. Since the first AC signal and the second AC signal are the same, the comparison signal and the reference signal can be compared to determine whether a fault has occurred in the transmission line. After the fault judgment is completed, if there is a fault in the transmission line, the area inside and outside the area is judged, and the equipment inside the area closest to the fault point is selected as the first equipment, and the two equipment outside the area closest to the fault point are selected as the second equipment and the third equipment. The distances between the second equipment and the third equipment and the fault point are calculated based on the impedance method and the standing wave method respectively. The distances from the second equipment and the third equipment to the fault point calculated based on the impedance method and the standing wave method are combined, and all fault points are topologically identified on the line topology map. The second equipment or the third equipment is used as the reference point to eliminate the fault points inside the area. The fault points outside the area are calculated as irrelevant points based on the LOF algorithm, and irrelevant points are eliminated. The distances of the remaining fault points are averaged as the final fault distance.

[0015] Furthermore, in the process of self-organizing the circuit breakers on each pole, the master device automatically numbers each connected slave device and transmits the number data to the main station of the distribution network. In this application, in the process of self-organizing the network, the slave devices connected subsequently are numbered, and after completion, the number data is collected and transmitted to the main station of the distribution network. When a fault occurs or the switch in the line needs to be controlled, only the master device needs to issue a command, which can be transparently transmitted to the device that needs to be operated.

[0016] Furthermore, the timing method is specifically as follows: a master device or a slave device sends out multiple continuous pulse signals through optical fiber at intervals, and the other devices calculate the pulse delay and calibrate the time according to their distance from the device sending the pulse signal. In the present application, the timing is performed once at intervals, and each time a master device or one of the slave devices sends out multiple continuous pulse signals, and the other devices calculate the pulse delay according to the distance between the pulse signal arrival point and the GPS positioning, and then calibrate the time of the device itself to achieve the consistency of the device time in the entire grid loop. The optical fiber timing is initiated by the master device, and before initiating, the communication confirms that the line is idle and determines the time point of the timing.

[0017] Furthermore, the basis for judging whether a transmission line fault occurs is as follows: if the amplitude and phase angle changes of the second AC signal received by the master device and the slave device compared to the amplitude and phase angle changes of the first AC signal received by the master device and the slave device do not exceed the anti-jitter value, it is judged that the transmission line has not failed; if the amplitude and phase angle changes of the second AC signal received by the master device and the slave device compared to the amplitude and phase angle changes of the first AC signal received by the master device and the slave device exceed the anti-jitter value, it is judged that there may be a fault in the transmission line.

[0018] Furthermore, if there may be a fault in the transmission line, the master device controls the slave devices to send the second AC signal in sequence again. The master device and the slave devices that have not sent the second AC signal at the current moment respectively collect the second AC signals sent by different slave devices, and compare them with the characteristic waveforms of the first AC signals collected by the master device and the slave devices when the transmission line is not faulty. If the change amplitude of the collected second AC signal compared to the collected first AC signal exceeds the anti-shake value, it is determined that the transmission line is faulty.

[0019] Further, the determination of inside and outside the area includes feeder terminal triggering mode and master device active triggering mode, wherein:

[0020] The feeder terminal triggering method is as follows: the main device collects all the information of the feeder terminal on the transmission line, determines whether it is inside or outside the area by the direction of the zero-sequence power, and thus obtains the approximate range of the fault point;

[0021] The specific active triggering mode of the master device is:

[0022] The master device polls and sends a third AC signal;

[0023] The slave device receives the third AC signal sent by the master device, calculates the amplitude of the acquired third AC signal, and communicates the amplitude to the master device, wherein the slave device with the largest amplitude deviation of the acquired third AC signal is the first device, and the two out-of-zone devices closest to the first device are selected as the second device and the third device.

[0024] Furthermore, the distances between the second device and the third device and the fault point are calculated based on the impedance method as follows:

[0025] The master device controls the first device to send a second pulse signal, and communicates the time when the first device sends the second pulse signal to the second device and the third device. Meanwhile, the first device records the second pulse signal sent by itself; the second pulse signal is the same as the first pulse signal;

[0026] The second device and the third device obtain a second pulse signal;

[0027] The second device and the third device send the acquired characteristic waveform of the second pulse signal and the characteristic waveform of the first pulse signal acquired from the first device when no fault occurs to the main device, and at the same time, the first device sends the characteristic waveform of the second pulse signal recorded by itself to the main device;

[0028] The master device performs FFT operations on the characteristic waveforms sent by the first device, the second device, and the third device, respectively, to obtain the peak values ​​at the corresponding pulse width frequency, which are the voltage peak values ​​V of the second pulse signal recorded by the first device and V of the second pulse signal recorded by the third device. a (i) The voltage peak value V of the second pulse signal detected by the second device b (i) The voltage peak value V of the second pulse signal detected by the third device c (i) Peak current I flowing through the first device a (i) The peak current I flowing through the second device b (i) Peak current I flowing through the third device c (i);

[0029] Calculate the voltage drop from the second device to the first device after a fault and the voltage drop from the third device to the first device :

[0030] ;

[0031] ;

[0032] Calculate the impedance change of the line from the second device to the first device after the fault and the impedance change of the line from the third device to the first device :

[0033] ;

[0034] ;

[0035] in, represents the coefficient of precision for frequency i;

[0036] Calculate the impedance per unit length of the line from the second device to the first device before the fault and the impedance per unit length of the line from the third device to the first device :

[0037] ;

[0038] ;

[0039] in, It represents the impedance of the line between the first device and the second device when the frequency is i before the fault; Indicates the actual distance from the first device to the second device; It represents the impedance of the line from the first device to the third device when the frequency is i before the fault; Indicates the actual distance from the first device to the third device;

[0040] Calculate the distance between the fault point and the second and third devices:

[0041] ;

[0042] ;

[0043] in, Indicates the distance between the fault point and the second device. Indicates the distance between the fault point and the third device.

[0044] Furthermore, the distances between the second device and the third device and the fault point are calculated based on the standing wave method as follows:

[0045] Obtain the time difference before the fault when the first pulse signal is transmitted from the first device to the second device and the third device, respectively, and record them as the first time difference and the second time difference ;

[0046] Calculate the transmission speed of the first pulse signal in the line between the first device and the second device and the transmission speed of the first pulse signal in the line between the first device and the third device, and record them as the first transmission speed and the second transmission speed :

[0047] ;

[0048] ;

[0049] in, Indicates the actual distance from the first device to the second device. Indicates the actual distance from the first device to the third device;

[0050] The master device controls the first device, the second device and the third device to send the second pulse signal respectively, and collects the characteristic waveform of the second pulse signal sent by itself;

[0051] The first device, the second device, and the third device respectively obtain characteristic waveforms of reflected waves of the second pulse signals sent by themselves and reflected from the fault point;

[0052] The first device, the second device, and the third device transmit the characteristic waveform of the second pulse signal sent by themselves and the characteristic waveform of the reflected wave to the main module;

[0053] Calculate the wavelength of the second pulse signal transmitted on the line between the first device and the second device and the wavelength of the second pulse signal transmitted on the line between the first device and the third device, and record them as the first wavelength respectively and the second wavelength :

[0054] ;

[0055] ;

[0056] Wherein, i represents the frequency of the second pulse signal;

[0057] Calculate the phase difference between the second pulse signal sent by the first device and its reflected wave, the phase difference between the second pulse signal sent by the second device and its reflected wave, and the phase difference between the second pulse signal sent by the third device and its reflected wave, and record them as the first phase difference , the second phase difference and the third phase difference :

[0058] ;

[0059] ;

[0060] ;

[0061] in, represents the peak time difference between the incident wave and the reflected wave of the second pulse signal sent by the first device, represents the peak time difference between the incident wave and the reflected wave of the second pulse signal sent by the second device, represents the peak time difference between the incident wave and the reflected wave of the second pulse signal sent by the third device;

[0062] Calculate the distance from the first device to the fault point , the distance from the second device to the fault point The distance from the third device to the fault point :

[0063] ;

[0064] ;

[0065] ;

[0066] Where n is a constant.

[0067] In summary, compared with the prior art, the present invention has the following beneficial effects: the present invention can cascade the equipment on the entire line through optical fiber communication, provide ultra-high time accuracy, and increase the accuracy of fault distance measurement; the present invention collects data from the equipment on the line through optical fiber and then calculates it through the internal edge device module, and uploads the final result to the distribution main station through a dedicated network, which basically eliminates network security problems, reduces the load of the main station, and is basically not affected by the network and region; the present invention determines whether a transmission line fails by actively sending pulses, calculates the fault distance by the attenuation and reflection of the sent pulse signal, is not affected by the collection at the time of the fault, avoids the situation where the fault characteristics are small and the misjudgment or missed judgment occurs, and can cover more fault types and a larger range; the present invention can more accurately perform fault distance measurement by calculating the actual transmission speed of the signal in the line, and avoids the positioning error that occurs when the speed of light is used as the transmission speed. BRIEF DESCRIPTION OF THE DRAWINGS

[0068] The drawings described herein are used to provide a further understanding of the embodiments of the present invention, constitute a part of this application, and do not constitute a limitation of the embodiments of the present invention. In the drawings:

[0069] Figure 1 is a flow chart of an embodiment of the present invention. DETAILED DESCRIPTION

[0070] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with embodiments and drawings. The exemplary embodiments of the present invention and their description are only used to explain the present invention and are not intended to limit the present invention.

[0071] Example:

[0072] like Figure 1 As shown, a fault location method based on a primary and secondary integrated pole-mounted circuit breaker comprises the following steps:

[0073] A pole-mounted circuit breaker is selected from among the pole-mounted circuit breakers of the transmission line as a master device, and the remaining pole-mounted circuit breakers are selected as slave devices; the master device is configured as a pole-mounted circuit breaker with the best 4G / 5G signal or a pole-mounted circuit breaker closest to the master station;

[0074] Optical fibers are connected between the circuit breakers on each pole to form a self-network;

[0075] The circuit breakers on each pole are timed by optical fiber;

[0076] When there is no fault in the power transmission line, the master device controls the slave device to send the first AC signal and the first pulse signal in sequence, and the master device and the slave device that has not sent the first AC signal and the first pulse signal at the current moment respectively collect and record the characteristic waveforms of the first AC signal and the first pulse signal sent by different slave devices;

[0077] Setting a signal sending interval time, the master device controls the slave devices to send the second AC signal in sequence after each interval time, the master device and the slave devices that have not sent the second AC signal at the current moment respectively collect the second AC signals sent by different slave devices, and compare them with the characteristic waveforms of the first AC signals collected by the master device and the slave devices when the transmission line is fault-free, to determine whether a fault occurs in the transmission line; the second AC signal is the same AC signal as the first AC signal;

[0078] If a transmission line fails, the device inside and outside the area is selected as the first device, and the two devices outside the area closest to the fault point are selected as the second and third devices;

[0079] Calculate the distances between the second device and the third device and the fault point based on the impedance method and the standing wave method respectively;

[0080] The distances from the second device and the third device to the fault point calculated based on the impedance method and the standing wave method are collected, and all fault points are topologically plotted on the line topology map. The second device or the third device is used as a reference point to eliminate the fault points within the area. The irrelevant points outside the area are calculated based on the LOF algorithm and eliminated. The distances of the remaining fault points are averaged as the final fault distance.

[0081] In the present application, the time synchronization between the pole-mounted circuit breakers on the transmission line is carried out through optical fiber, which is not affected by the environment, and more accurate time synchronization information can be obtained by adding the propagation delay of light; in the present application, an optical fiber self-organized network is used between the pole-mounted circuit breakers, and the data collected by the pole-mounted circuit breakers are transmitted through optical fiber, which basically eliminates network security problems, reduces the load of the main station, and is basically not affected by the network and region. In the present application, different from the prior art that performs fault judgment by passively detecting the first wave of the fault, the fault detection of the present application adopts an active detection method, and determines whether the transmission line has a fault by actively sending an AC signal to the transmission line by the pole-mounted circuit breaker. In the present application, when there is no fault, the master device controls each slave device to send a first AC signal to the transmission line in turn, and the master device and the slave device that has not sent the first AC signal receive the first AC signal sent from each slave device as a reference signal; at regular intervals, the master device controls each slave device to send a second AC signal in turn, and the master device and the slave device that has not sent the second AC signal receive the second AC signal sent from each slave device as a comparison signal. Since the first AC signal and the second AC signal are the same, the comparison signal and the reference signal can be compared to determine whether a fault has occurred in the transmission line. After the fault judgment is completed, if there is a fault in the transmission line, the area is judged inside and outside the area, and the equipment in the area closest to the fault point is selected as the first equipment, and the two equipment outside the area closest to the fault point are selected as the second equipment and the third equipment, and then the distance between the second equipment and the third equipment and the fault point is calculated based on the impedance method and the standing wave method respectively. The distances from the second equipment and the third equipment to the fault point calculated based on the impedance method and the standing wave method are combined, and all fault points are topologically identified on the line topology map, and the second equipment or the third equipment is used as a reference point to eliminate the fault points in the area. The fault points outside the area are calculated based on the LOF algorithm to calculate irrelevant points, and the irrelevant points are eliminated. The distances of the remaining fault points are averaged as the final fault distance. It should be noted that the distance of irrelevant fault points is eliminated by the LOF algorithm, that is, the local outlier factor of each fault point is calculated by the LOF algorithm, and the fault points with outlier factors greater than 1 are eliminated. This is a prior art and will not be elaborated on here.

[0082] It should be noted that in the present application, the pole-mounted circuit breaker refers to a primary and secondary integrated pole-mounted circuit breaker, referred to as a pole-mounted circuit breaker, including a circuit breaker, a high-voltage coupler, an optical fiber transceiver, a side equipment module and a feeder terminal; wherein the circuit breaker has a switching function, which is used to open and close the line, and can disconnect the line when a fault occurs at the lower level. The circuit breaker is provided with a capacitive voltage divider type voltage sensor and a Rogowski coil current sensor. The capacitive voltage divider type voltage sensor is used to collect voltage signals and coupled signals, and the Rogowski coil current sensor is used to collect line current signals and coupled signals; the high-voltage coupler is composed of a mutual inductor coil and a capacitor, and can inject AC and pulse signals into the line through coupling, and at the same time the high voltage The coupler has PT function, which converts 10kV line power into conventional 220V mains power for use by pole-mounted circuit breakers; the fiber optic transceiver is used to convert optical-electrical signals, receive and send information, and cascade the FTUs on the line through fiber optic communication; the edge device module is used to collect (collect three-phase voltage and three-phase current), calculate the voltage and current signals output by the circuit breaker, calculate the characteristic values ​​of the time domain and frequency domain through the FFT algorithm, control the cascade communication of the pole-mounted circuit breakers on the entire line, and is equipped with a GPS module for positioning through GPS; the feeder terminal is used to calculate whether a fault occurs in the line and control the action of the circuit breaker, and has various functions of a standard feeder terminal. In addition, each pole-mounted circuit breaker is connected by optical fiber, which is arranged together with the transmission cable. The modules between the pole-mounted circuit breakers are connected by cables, among which the circuit breaker is connected to the feeder terminal by cable, which contains position signals, control signals, and analog signals. The feeder terminal can control the action of the circuit breaker, and the analog signals are respectively given to the feeder terminal and the side equipment module; the high-voltage coupler is connected to the feeder terminal by cable, which contains power and coupling control lines, and can provide power for the pole-mounted circuit breaker; the optical fiber transceiver is located inside the feeder terminal, connected to other optical fiber transceivers by optical fiber, and connected to the side equipment module after being converted into electrical signals; the side equipment module is located inside the feeder terminal, connected to the optical fiber transceiver and the feeder terminal by cable, and connected to the high-voltage coupler by cable, collects the analog signal output by the circuit breaker, and the power is provided by the feeder terminal, and can communicate with the feeder terminal through cable; the feeder terminal is connected to various components through cables, and supplies power to the side equipment module and the optical fiber transceiver.

[0083] Furthermore, in the present application, due to the distance between the devices and the differences between the lines, the AC signals and pulse signals that can be received by each device are slightly different. Therefore, in the present application, based on experience, the first AC signal includes AC signals of multiple frequencies (10KHz and 100KHz), and the first pulse signal includes pulse signals of multiple frequencies (10KHz, 20KHz, 50KHz, 80KHz, 100KHz), so that each device can receive the AC signal and the pulse signal. When sending AC signals or pulse signals of multiple frequencies, the AC signals or pulse signals of multiple frequencies are sent in sequence. It should be noted that since sending the second AC signal to the line may affect the power quality of the line power supply, the interval time for the master device to control the slave device to send the second AC signal is generally set to once every 2 hours or more based on experience.

[0084] Furthermore, in the process of self-organizing the circuit breakers on each pole, the master device automatically numbers each connected slave device and transmits the number data to the main station of the distribution network. In this application, in the process of self-organizing the network, the slave devices connected subsequently are numbered, and after completion, the number data is collected and transmitted to the main station of the distribution network. When a fault occurs or the switch in the line needs to be controlled, only the master device needs to issue a command, which can be transparently transmitted to the device that needs to be operated.

[0085] Furthermore, the timing method is specifically as follows: a master device or a slave device sends out multiple continuous pulse signals through optical fiber at intervals, and the other devices calculate the pulse delay and calibrate the time according to their distance from the device sending the pulse signal. In the present application, the timing is performed once at intervals, and each time a master device or one of the slave devices sends out multiple continuous pulse signals, and the other devices calculate the pulse delay according to the distance between the pulse signal arrival point and the GPS positioning, and then calibrate the time of the device itself to achieve the consistency of the device time in the entire grid loop. The optical fiber timing is initiated by the master device, and before initiating, the communication confirms that the line is idle and determines the time point of the timing.

[0086] Furthermore, the basis for judging whether a transmission line fails is as follows: if the amplitude and phase angle of the second AC signal received by the master device and the slave device do not exceed the anti-shake value compared to the amplitude and phase angle of the first AC signal received by the master device and the slave device, it is judged that the transmission line has not failed; if the amplitude and phase angle of the second AC signal received by the master device and the slave device exceed the anti-shake value compared to the amplitude and phase angle of the first AC signal received by the master device and the slave device, it is judged that there may be a fault in the transmission line. Specifically, in the present application, the anti-shake value is generally set to 5%, which can be slightly modified according to the operation of the line. If the line grid structure in the area has not changed significantly, the impedance and inductance of each conductor itself remain basically unchanged, and only the capacitive reactance will change slightly due to weather changes.

[0087] Furthermore, if there may be a fault in the transmission line, the master device controls the slave devices to send the second AC signal in sequence again. The master device and the slave devices that have not sent the second AC signal at the current moment respectively collect the second AC signals sent by different slave devices, and compare them with the characteristic waveforms of the first AC signals collected by the master device and the slave devices when the transmission line is not faulty. If the change amplitude of the collected second AC signal compared to the collected first AC signal exceeds the anti-shake value, it is determined that the transmission line is faulty.

[0088] Further, the determination of inside and outside the area includes feeder terminal triggering mode and master device active triggering mode, wherein:

[0089] The feeder terminal triggering method is as follows: the main device collects all the information of the feeder terminal on the transmission line, determines whether it is inside or outside the area by the direction of the zero-sequence power, and thus obtains the approximate range of the fault point;

[0090] The specific active triggering mode of the master device is:

[0091] The master device polls and sends a third AC signal;

[0092] The slave device receives the third AC signal sent by the master device, calculates the amplitude of the acquired third AC signal, and communicates the amplitude to the master device, wherein the slave device with the largest amplitude deviation of the acquired third AC signal is the first device, and the two out-of-zone devices closest to the first device are selected as the second device and the third device. In the present application, the judgment method of inside and outside the zone includes a feeder terminal triggering method and a master device active triggering method, wherein the feeder terminal triggering method judges inside and outside the zone by judging the direction of zero-sequence power. This method is a prior art and will not be described in detail here. The master device active triggering method controls the high-voltage coupler to poll and send 10KHz and 100KHz AC signals through the side device module of the master device to judge the device with the largest amplitude deviation, and takes the device as the first device, which is the device inside the zone, and selects the two sets of out-of-zone devices closest to the first device as the second device and the third device. It should be noted that the inside and outside of the zone can be determined by determining the direction of the current through the device inside the zone, and the second device and the third device can be directly determined.

[0093] Furthermore, the distances between the second device and the third device and the fault point are calculated based on the impedance method as follows:

[0094] The master device controls the first device to send a second pulse signal, and communicates the time when the first device sends the second pulse signal to the second device and the third device. At the same time, the first device records the second pulse signal sent by itself; the second pulse signal is the same as the first pulse signal;

[0095] The second device and the third device obtain a second pulse signal;

[0096] The second device and the third device send the acquired characteristic waveform of the second pulse signal and the characteristic waveform of the first pulse signal acquired from the first device when no fault occurs to the main device, and at the same time, the first device sends the characteristic waveform of the second pulse signal recorded by itself to the main device;

[0097] The master device performs FFT operations on the characteristic waveforms sent by the first device, the second device, and the third device, respectively, to obtain the peak values ​​at the corresponding pulse width frequency, which are the voltage peak values ​​V of the second pulse signal recorded by the first device and V of the second pulse signal recorded by the third device. a (i) The voltage peak value V of the second pulse signal detected by the second device b (i) The voltage peak value V of the second pulse signal detected by the third device c (i) Peak current I flowing through the first device a (i) The peak current I flowing through the second device b (i) Peak current I flowing through the third device c (i);

[0098] Calculate the voltage drop from the second device to the first device after a fault and the voltage drop from the third device to the first device :

[0099] ;

[0100] ;

[0101] Calculate the impedance change of the line from the second device to the first device after the fault and the impedance change of the line from the third device to the first device :

[0102] ;

[0103] ;

[0104] in, represents the coefficient of precision for frequency i;

[0105] Calculate the impedance per unit length of the line from the second device to the first device before the fault and the impedance per unit length of the line from the third device to the first device :

[0106] ;

[0107] ;

[0108] in, It represents the impedance of the line between the first device and the second device when the frequency is i before the fault; Indicates the actual distance from the first device to the second device; It represents the impedance of the line from the first device to the third device when the frequency is i before the fault; Indicates the actual distance from the first device to the third device;

[0109] Calculate the distance between the fault point and the second and third devices:

[0110] ;

[0111] ;

[0112] in, Indicates the distance between the fault point and the second device. Indicates the distance between the fault point and the third device.

[0113] Furthermore, the distances between the second device and the third device and the fault point are calculated based on the standing wave method as follows:

[0114] Obtain the time difference before the fault when the first pulse signal is transmitted from the first device to the second device and the third device, respectively, and record them as the first time difference and the second time difference ;

[0115] Calculate the transmission speed of the first pulse signal in the line between the first device and the second device and the transmission speed of the first pulse signal in the line between the first device and the third device, and record them as the first transmission speed and the second transmission speed :

[0116] ;

[0117]

[0118] in, Indicates the actual distance from the first device to the second device. Indicates the actual distance from the first device to the third device;

[0119] The master device controls the first device, the second device and the third device to send the second pulse signal respectively, and collects the characteristic waveform of the second pulse signal sent by itself;

[0120] The first device, the second device, and the third device respectively obtain characteristic waveforms of reflected waves of the second pulse signals sent by themselves and reflected from the fault point;

[0121] The first device, the second device, and the third device transmit the characteristic waveform of the second pulse signal sent by themselves and the characteristic waveform of the reflected wave to the main module;

[0122] Calculate the wavelength of the second pulse signal transmitted on the line between the first device and the second device and the wavelength of the second pulse signal transmitted on the line between the first device and the third device, and record them as the first wavelength respectively and the second wavelength :

[0123]

[0124]

[0125] Wherein, i represents the frequency of the second pulse signal;

[0126] Calculate the phase difference between the second pulse signal sent by the first device and its reflected wave, the phase difference between the second pulse signal sent by the second device and its reflected wave, and the phase difference between the second pulse signal sent by the third device and its reflected wave, and record them as the first phase difference , the second phase difference and the third phase difference :

[0127]

[0128]

[0129]

[0130] in, represents the peak time difference between the incident wave and the reflected wave of the second pulse signal sent by the first device, represents the peak time difference between the incident wave and the reflected wave of the second pulse signal sent by the second device, represents the peak time difference between the incident wave and the reflected wave of the second pulse signal sent by the third device;

[0131] Calculate the distance from the first device to the fault point , the distance from the second device to the fault point The distance from the third device to the fault point :

[0132]

[0133]

[0134]

[0135] Where n is a constant. In this application, each constant n is substituted into the calculation to obtain n groups of distance values, where each group of distance values ​​includes , , , each set of distance values ​​is topologically mapped out on the line, and multiple close fault points or a unique fault point determined by three distance values ​​are selected as the final fault point obtained based on the standing wave method.

[0136] In the present application, since a device may receive pulse signals of multiple frequencies, the distances from the second device to the fault point and the distances from the third device to the fault point that are finally calculated are multiple. Therefore, all data sets calculated by the impedance method and the standing wave method are used to topologically identify all fault points on the line topology map, and the second device or the third device is used as a reference point to eliminate the fault points in the area. The fault points outside the area are calculated based on the LOF algorithm to identify irrelevant points, and the irrelevant points are eliminated. The distances of the remaining fault points are averaged as the final fault distance. It should be noted that after eliminating irrelevant fault points, the remaining fault points have been topologically obtained in the topology map, that is, the distances of the remaining fault points from the first device, the second device, and the third device can all be obtained, so the final fault distance can be calculated with the first device, the second device, or the third device as a reference.

[0137] The specific implementation methods described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific implementation method of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A fault location method based on a primary and secondary integrated pole-mounted circuit breaker, characterized in that: The following steps are involved: A pole-mounted circuit breaker is selected from among the pole-mounted circuit breakers of the transmission line as a master device, and the remaining pole-mounted circuit breakers are selected as slave devices; the master device is configured as a pole-mounted circuit breaker with the best 4G / 5G signal or a pole-mounted circuit breaker closest to the master station; Optical fibers are connected between the circuit breakers on each pole to form a self-network; The circuit breakers on each pole are timed by optical fiber; When there is no fault in the power transmission line, the master device controls the slave device to send the first AC signal and the first pulse signal in sequence, and the master device and the slave device that has not sent the first AC signal and the first pulse signal at the current moment respectively collect and record the characteristic waveforms of the first AC signal and the first pulse signal sent by different slave devices; Setting a signal sending interval time, the master device controls the slave devices to send the second AC signal in sequence after each interval time, the master device and the slave devices that have not sent the second AC signal at the current moment respectively collect the second AC signals sent by different slave devices, and compare them with the characteristic waveforms of the first AC signals collected by the master device and the slave devices when the transmission line is fault-free, to determine whether a fault occurs in the transmission line; the second AC signal is the same AC signal as the first AC signal; If a transmission line fails, the device inside and outside the area is selected as the first device, and the two devices outside the area closest to the fault point are selected as the second and third devices; Calculate the distances between the second device and the third device and the fault point based on the impedance method and the standing wave method respectively; The distances from the second device and the third device to the fault point calculated based on the impedance method and the standing wave method are collected, and all fault points are topologically plotted on the line topology map. The second device or the third device is used as a reference point to eliminate the fault points within the area. The irrelevant points outside the area are calculated based on the LOF algorithm and eliminated. The distances of the remaining fault points are averaged as the final fault distance; The distances between the second device and the third device and the fault point are calculated based on the standing wave method as follows: Obtain the time difference before the fault when the first pulse signal is transmitted from the first device to the second device and the third device, respectively, and record them as the first time difference and the second time difference ; Calculate the transmission speed of the first pulse signal in the line between the first device and the second device and the transmission speed of the first pulse signal in the line between the first device and the third device, and record them as the first transmission speed respectively and the second transmission speed : in, Indicates the actual distance from the first device to the second device. Indicates the actual distance from the first device to the third device; The master device controls the first device, the second device and the third device to send the second pulse signal respectively, and collects the characteristic waveform of the second pulse signal sent by itself; The first device, the second device, and the third device respectively obtain characteristic waveforms of reflected waves of the second pulse signals sent by themselves and reflected from the fault point; The first device, the second device, and the third device transmit the characteristic waveform of the second pulse signal sent by themselves and the characteristic waveform of the reflected wave to the main module; Calculate the wavelength of the second pulse signal transmitted on the line between the first device and the second device and the wavelength of the second pulse signal transmitted on the line between the first device and the third device, and record them as the first wavelength respectively and the second wavelength : Wherein, i represents the frequency of the second pulse signal; Calculate the phase difference between the second pulse signal sent by the first device and its reflected wave, the phase difference between the second pulse signal sent by the second device and its reflected wave, and the phase difference between the second pulse signal sent by the third device and its reflected wave, and record them as the first phase difference , the second phase difference and the third phase difference : in, represents the peak time difference between the incident wave and the reflected wave of the second pulse signal sent by the first device, represents the peak time difference between the incident wave and the reflected wave of the second pulse signal sent by the second device, represents the peak time difference between the incident wave and the reflected wave of the second pulse signal sent by the third device; Calculate the distance from the first device to the fault point , the distance from the second device to the fault point The distance from the third device to the fault point : Where n is a constant; Substitute each constant n into the calculation to obtain n groups of distance values, where each group of distance values ​​includes , , ; Each set of distance values ​​is topologically mapped out on the line, and multiple close fault points or a unique fault point determined by three distance values ​​are selected as the final fault point obtained based on the standing wave method.

2. A fault location method based on a primary and secondary integrated pole-mounted circuit breaker according to claim 1, characterized in that: During the self-networking process of the circuit breakers on each pole, the master device automatically numbers each connected slave device and transmits the number data to the distribution network master station.

3. A fault location method based on a primary and secondary integrated pole-mounted circuit breaker according to claim 1, characterized in that: The specific time synchronization method is: the master device or a slave device sends multiple continuous pulse signals through the optical fiber at intervals, and the other devices calculate the pulse delay and calibrate the time based on their distance from the device sending the pulse signal.

4. A fault location method based on a primary and secondary integrated pole-mounted circuit breaker according to claim 1, characterized in that: The basis for judging whether a transmission line fails is: if the amplitude and phase angle of the second AC signal received by the master device and the slave device do not exceed the anti-shake value compared with the amplitude and phase angle of the first AC signal received by the master device and the slave device, it is judged that the transmission line does not fail; If the amplitude and phase angle of the second AC signal received by the master device and the slave device vary by more than the anti-shake value compared to the amplitude and phase angle of the first AC signal received by the master device and the slave device, it is determined that there may be a fault in the transmission line.

5. A fault location method based on a primary and secondary integrated pole mounted circuit breaker according to claim 4, characterized in that: If there may be a fault in the transmission line, the master device controls the slave devices to send the second AC signal in sequence again. The master device and the slave devices that have not sent the second AC signal at the current moment respectively collect the second AC signals sent by different slave devices, and compare them with the characteristic waveforms of the first AC signals collected by the master device and the slave devices when the transmission line is not faulty. If the change amplitude of the collected second AC signal compared to the collected first AC signal exceeds the anti-shake value, it is determined that the transmission line is faulty.

6. A fault location method based on a primary and secondary integrated pole-mounted circuit breaker according to claim 1, characterized in that: The judgment of inside and outside the area includes the feeder terminal triggering method and the main equipment active triggering method, among which, The feeder terminal triggering method is as follows: the main device collects all the information of the feeder terminal on the transmission line, determines whether it is inside or outside the area by the direction of the zero-sequence power, and thus obtains the approximate range of the fault point; The specific active triggering mode of the master device is: The master device polls and sends a third AC signal; The slave device receives the third AC signal sent by the master device, calculates the amplitude of the acquired third AC signal, and communicates the amplitude to the master device, wherein the slave device with the largest amplitude deviation of the acquired third AC signal is the first device, and the two out-of-zone devices closest to the first device are selected as the second device and the third device.

7. A fault location method based on a primary and secondary integrated pole mounted circuit breaker according to claim 1, characterized in that: The distance between the second device and the third device and the fault point is calculated based on the impedance method as follows: The master device controls the first device to send the second pulse signal, and communicates the time when the first device sends the second pulse signal to the second device and the third device. Meanwhile, the first device records the second pulse signal sent by itself. The second pulse signal is the same as the first pulse signal; The second device and the third device obtain a second pulse signal; The second device and the third device send the acquired characteristic waveform of the second pulse signal and the characteristic waveform of the first pulse signal acquired from the first device when no fault occurs to the main device, and at the same time, the first device sends the characteristic waveform of the second pulse signal recorded by itself to the main device; The master device performs FFT operations on the characteristic waveforms sent by the first device, the second device, and the third device, respectively, to obtain the peak values ​​at the corresponding pulse width frequency, which are the voltage peak values ​​V of the second pulse signal recorded by the first device and V of the second pulse signal recorded by the third device. a (i) The voltage peak value V of the second pulse signal detected by the second device b (i) The voltage peak value V of the second pulse signal detected by the third device c (i) Peak current I flowing through the first device a (i) The peak current I flowing through the second device b (i) Peak current I flowing through the third device c (i); Calculate the voltage drop from the second device to the first device after a fault and the voltage drop from the third device to the first device : Calculate the impedance change of the line from the second device to the first device after the fault And the impedance change value of the line from the third device to the first device : in, represents the coefficient of precision for frequency i; Calculate the impedance per unit length of the line from the second device to the first device before the fault and the impedance per unit length of the line from the third device to the first device : in, It represents the impedance of the line between the first device and the second device when the frequency is i before the fault; Indicates the actual distance from the first device to the second device; It represents the impedance of the line from the first device to the third device when the frequency is i before the fault; Indicates the actual distance from the first device to the third device; Calculate the distance between the fault point and the second and third devices: in, Indicates the distance between the fault point and the second device. Indicates the distance between the fault point and the third device.

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