38results about How to "The principle of ranging is simple" patented technology

The invention discloses a method for ranging a single-phase earth fault of a line by using single-end electric quantity. The method comprises the steps of measuring the fault phase voltage, the fault phase negative sequence current, the fault phase current and the zero sequence current in a transmission line protection mounting location; calculating an imaginary part of the ratio between the fault phase voltage and the fault phase negative sequence current; calculating an imaginary part of the ratio between potential drop per unit length of the transmission line and the fault phase negative sequence current; and dividing the imaginary part of the ratio between the fault phase voltage and the fault phase negative sequence current by the imaginary part of the ratio between the potential drop per unit length of the transmission line and the fault phase negative sequence current to obtain the fault distance from the transmission line protection mounting location to the single-phase earth fault point. The method uses the single-end electric quantity to achieve accurate measurement of the single-phase earth fault distance of the transmission line, overcomes the influence of transition resistance and load current on the fault distance measuring accuracy, the ranging principle is simple, the program is easy to achieve, and the method has the advantages of small calculation amount, high ranging speed and high real-time performance.

The invention discloses a line single-phase ground fault single-terminal location method capable of preventing influences of both transitional resistance and load current. According to the method, the voltage phase angle of a single-phase ground fault point is calculated by utilizing the fault-phase negative sequence voltage of the relay location of a transmission line and the positive sequence impedance of the transmission line per unit length; the imaginary part of the voltage drop from the relay location of the transmission line to the single-phase ground fault point is calculated according to the characteristic that the voltage along the transmission line is in linear monotone decreasing; and the imaginary part of the voltage drop from the relay location of the transmission line to the single-phase ground fault point is divided by the imaginary part of the voltage drop of the transmission line per unit length to obtain the fault location. The line single-phase ground fault single-terminal location method solves the problem that the transitional resistance and the load current influence the single-terminal fault location precision, is high in single-terminal location precision, simple in location principle and easy in program implementation, and does not need to adopt the search algorithm, so that direct calculation of the fault location is realized, location speed is quick and the real-time performance is strong.

The invention discloses a line single-phase earthing fault single-end ranging method realized by utilizing voltage drop imaginary part characteristics. The method utilizes the fault phase negative sequence voltage and the transmission line positive sequence impedance per unit length to calculate the single-phase earthing fault point voltage phase angle, and further calculate an additional fault distance caused by a transition resistance, and the imaginary part of the ratio of the fault phase voltage to the zero sequence compensating current divides the imaginary part of the transmission line positive sequence impedance per unit length and then subtracts the additional fault distance to obtain a fault distance between the transmission line protection mounting part and the single-phase earthing fault point. The method provided by the invention overcomes the impact defects of the transition resistance and load current on single-end fault ranging precision, the ranging precision is high when the transmission line has a single-phase high resistance earthing fault, the ranging principle is simple, the program is easily realized, the fault distance is directly calculated without using a search algorithm, the ranging speed is quick, and the real-time is strong.

The invention discloses a line single-phase earth fault single-terminal ranging method implemented by the aid of sequence components. The line single-phase earth fault single-terminal ranging method includes converting negative-sequence voltages of a power transmission line single-phase earth fault point into an equivalent zero-sequence voltage; accurately computing the fault distance according to a fault characteristic that a certain zero-sequence voltage of a power transmission line single-phase earth fault point is equal to the equivalent zero-sequence voltage so as to implement power transmission line single-phase earth fault single-terminal ranging. The line single-phase earth fault single-terminal ranging method has the advantages that the power transmission line single-phase earth fault single-terminal ranging is implemented according to distribution characteristics of the zero-sequence voltages along a power transmission line, influence of transition resistance on the ranging precision is eliminated in principle, influence of load currents and fault positions is prevented, and the ranging precision is high; a ranging principle of the method is simple, programs are easy to implement, the fault distance does not need to be directly computed by a search algorithm, and the method is high in ranging speed and instantaneity.

The invention discloses an electric transmission line phase fault single-ended distance measuring method. The electric transmission line phase fault single-ended distance measuring method includes the following steps of working out equivalent resistance through the voltage between fault phases, the current between the fault phases, and the negative-sequence current between the fault phases at the electric transmission line relay location, obtaining the voltage of a phase fault point through the fact that the equivalent resistance is multiplied by the negative-sequence current between the fault phases, working out the real part of a ratio between the voltage of the phase fault point and the voltage drop of an electric transmission line of per unit length, obtaining the additional fault distance caused by a transition resistor, and obtaining the fault distance from the electric transmission line relay location to the phase fault point through the difference between the real part of the ratio between the voltage between fault phases and the voltage drop of the electric transmission line of per unit length and the additional fault distance. The electric transmission line phase fault single-ended distance measuring method solves the problem that the transition resistor influences the precision of electric transmission line phase fault single-ended distance measuring, has high distance measuring precision and is simple in distance measuring principle. In addition, according to the electric transmission line phase fault single-ended distance measuring method, a program is easy to achieve, the fault distance is directly worked out without the need for application of search algorithms, distance measuring is fast, and the instantaneity is strong.

The invention discloses a method for realizing line interphase fault single-ended distance measurement by means of real part characteristics of voltage drop. According to the method, a voltage phase angle at an interphase short fault point is calculated by using fault interphase negative sequence voltage and positive sequence impedance of an electric transmission line per unit length, so that an additional fault distance generated due to transition resistance is calculated, and the fault distance from the electric transmission line protection installation position to the interphase short fault point is obtained by subtracting the additional fault distance generated due to transition resistance from the real part of a ratio of the fault interphase voltage to the voltage drop of the electric transmission line per unit length. The method solves the problem that the transition resistance and load current influence the accuracy of single-ended fault distance measurement; and when a high resistance short fault between phases of the electric transmission line happens, the method has high distance measurement accuracy, the distance measurement principle is simple, the procedure is easy to implement, the fault distance can be directly calculated without a search algorithm, the distance measurement speed is high, and the real-time performance is high.

The invention relates to a dynamic-real-time-parameter-based along-line voltage cross correction fault ranging method of a T type line. On the basis of electrical information of a T type line under the normal operating condition, real-time parameters of three-terminal lines are calculated dynamically in real time and calculation errors of the real-time parameters of the lines are corrected based on a genetic algorithm; after a fault occurs at one line, voltages of T nodes are calculated respectively based on a line distribution parameter line model under the modified parameters and a fault branch is determined by voltage comparison; two non-fault branches are equivalent to T terminals and form, together with one end of the fault branch, a two-terminal power transmission line model; and then two straight lines are formed by measuring voltages at two sides and calculating opposite-side voltages and an intersection point is calculated based on intersection of the straight lines, so that afault ranging method is formed. Therefore, the line parameter error can be adjusted dynamically in real time; the fault ranging precision is improved; and the engineering practicability is high.

The invention provides a laser range finding system. The system comprises a clock chip, a laser emitter, a laser receiver, a frequency mixing device and a microprocessor, wherein the clock chip outputs a local oscillator signal, a first main vibration signal and a sampling trigger signal; the laser emitter is connected to the clock chip, receives the first main vibration signal and emits a first laser beam to a target object under the modulation of the first main vibration signal, and the target object reflects a second laser beam; the laser receiver is arranged on a second laser beam path, receives the second laser beam and generates a second main vibration signal; the frequency mixing device is connected to the clock chip and the laser receiver, and receives and mixes the local oscillator signal and the second main vibration signal so as to generate an intermediate frequency signal; and the microprocessor is connected to the clock chip and the frequency mixing device, receives the intermediate frequency signal and the sampling trigger signal, calculates a phase difference and calculates a distance between the laser emitter and the target object according to the phase difference.By using the above technical scheme, through using the control of the clock chip, an existing laser range finding scheme is simplified, manufacturing cost is saved and product stability is increased.

The invention discloses a method utilizing lumped parameters to realize line interphase fault single-terminal location. According to the method, the lumped parameters are adopted to describe the physical properties of voltage and current transmission of a transmission line; the fault interphase negative sequence current phase angle of a relay location of the transmission line is adopted to calculate the voltage phase angle of an interphase short circuit fault point; and the fault location is calculated according to the linear relationship between the voltage drop from the relay location of the transmission line to the interphase short circuit fault point and the fault location. According to the invention, as the fault location is calculated according to the linear relationship between the voltage drop from the relay location of the transmission line to the interphase short circuit fault point and the fault location, the influences of the transitional resistance and the load current to the location precision are avoided, the location precision is high, the location principle is simple and the practicability is strong. The method can directly calculate the fault distance without adopting the search algorithm, and is high in location speed and strong in real-time performance.

The invention discloses an additional fault distance impact resistant line single-phase earthing fault single-end ranging method, which comprises the following steps of firstly, measuring fault phase voltage, fault phase negative sequence current, fault phase current and zero sequence current at a protection mounting part of a transmission line to be used as an input quantity; utilizing fault phase electrical quantity to calculate an additional fault distance caused by a transition resistance, and subtracting the additional fault distance caused by the transition resistance from the ratio of fault phase voltage to transmission line voltage drop per unit length to obtain the fault distance between the transmission line protection mounting part and a single-phase earthing fault point. The method provided by the invention overcomes the impact defects of the transition resistance and load current on single-end fault ranging precision, the ranging precision is high when the transmission line has a single-phase high resistance earthing fault, the ranging principle is simple, the program is easily realized, the fault distance is directly calculated without using a search algorithm, the ranging speed is quick, and the real-timeness is strong.

The invention discloses an ultrasonic-based intelligent induction shower device, which relates to the field of induction shower devices; it includes a top spray shower and a top spray shower inlet pipe, the top spray shower includes an upper plate and a spray head, and the upper plate There is a cylinder between the nozzle and the nozzle, a sliding structure is fixed above the nozzle, and a spherical structure is arranged under the water inlet pipe of the top sprinkler. The structure is sleeved on the spherical structure, so that the sliding structure and the spherical structure form a ball twist connection, so that the nozzle can be rotated under the action of the cylinder; it also includes an induction device, which includes a single-chip microcomputer and an ultrasonic circuit, and the ultrasonic circuit It is electrically connected with the cylinder and the single-chip electromechanical; the invention solves the problem that the fixed design of the existing overhead shower device cannot adjust the spraying angle according to the position of the bather, and achieves the effect of real-time adjustment of the spraying angle of the overhead shower.

The invention discloses a circuit interphase fault single-terminal location method capable of preventing additional fault location influence. According to the method, the fault interphase electrical capacity at the relay location of a transmission line is adopted to calculate additional fault location aroused by transitional resistance, and the ratio of the fault interphase voltage and the voltage drop of the transmission line per unit length subtracts the additional fault location aroused by the transitional resistance to obtain the fault location from the relay location of the transmission line to the interphase short circuit fault point. The method provided by the invention solves the problem that the transitional resistance and the load current influence the single-terminal fault location precision, has high location precision and simple location principle, achieves easy program implementation without directly calculating the fault location through the search algorithm, and is high in location speed and strong in real-time performance.

Based on the dynamic real-time parameters, the voltage cross correction fault location method along the T-shaped line uses the electrical information of the T-shaped line under normal operating conditions to dynamically calculate the real-time parameters of the three-terminal line in real time, and corrects the calculation error of the real-time parameters of the line based on the genetic algorithm; After a line fault occurs, based on the line distribution parameter line model under the modified parameters, the T node voltage is calculated respectively, and the faulty branch is judged by voltage comparison; then the two non-faulty branches are equivalent to the T terminal, which forms The two-end transmission line model; finally, two straight lines are formed by using the measured voltage on both sides and the calculated voltage on the opposite side, and the intersection point is obtained based on the intersection of the straight lines to form a fault location method. The invention can dynamically adjust line parameter errors in real time, improves fault distance measurement accuracy, and has strong engineering practicability.

The invention discloses a line single-phase ground fault single-terminal location method capable of preventing influences of both transitional resistance and load current. According to the method, the voltage phase angle of a single-phase ground fault point is calculated by utilizing the fault-phase negative sequence voltage of the relay location of a transmission line and the positive sequence impedance of the transmission line per unit length; the imaginary part of the voltage drop from the relay location of the transmission line to the single-phase ground fault point is calculated according to the characteristic that the voltage along the transmission line is in linear monotone decreasing; and the imaginary part of the voltage drop from the relay location of the transmission line to the single-phase ground fault point is divided by the imaginary part of the voltage drop of the transmission line per unit length to obtain the fault location. The line single-phase ground fault single-terminal location method solves the problem that the transitional resistance and the load current influence the single-terminal fault location precision, is high in single-terminal location precision, simple in location principle and easy in program implementation, and does not need to adopt the search algorithm, so that direct calculation of the fault location is realized, location speed is quick and the real-time performance is strong.

The invention discloses a method of achieving interphase short circuit fault distance measurement of a line by means of single-end electric quantities. The method includes measuring fault interphase voltage, fault interphase currents and fault interphase negative-sequence currents on a protective installation portion of a power transmission line, calculating an imaginary part of a ratio of the fault interphase voltage and the fault interphase negative-sequence currents, calculating an imaginary part of a ratio of voltage drop of the power transmission line per unit length and the fault interphase negative-sequence currents, dividing the imaginary part of the ratio of the voltage drop of the power transmission line per unit length and the fault interphase negative-sequence currents by the imaginary part of the ratio of the fault interphase voltage and the fault interphase negative-sequence currents, and obtaining a fault distance from the protective installation portion of the power transmission line to an interphase short circuit fault point. The method achieves precise measurement of the interphase short circuit fault distance of the power transmission line by means of the single-end electric quantities, and eliminates influences of transition resistance and load currents on measurement precision of the fault distance. Distance measuring principles are simple, programs are easy to achieve, operation amount is little, the distance measuring speed is high, and instantaneity is strong.

The invention discloses a single-end distance measurement method for an electric transmission line single-phase earth fault. The method comprises the following steps: calculating equivalent resistance by using fault phase electric quantity in the electric transmission line protection installing place, multiplying the equivalent resistance by fault phase negative sequence current to acquire the single-phase earth fault point voltage, calculating a real part of a ratio between single-phase earth fault point voltage and electric transmission line voltage drop per unit length to acquire an additional fault distance caused by transition resistance, and using the real part of the ratio to subtract the additional fault distance so as to acquire a fault distance from the electric transmission line protection installing place to the single-phase earth fault point. According to the method, the problem about the effect of transition resistance on single-end fault distance measurement accuracy is solved, higher distance measurement accuracy is achieved in case of electric transmission line single phase high resistance ground fault, the distance measurement principle is simple, the process is easy to realize, the fault distance is directly calculated without adopting the search algorithm, the distance measurement speed is high, and the instantaneity is high.

The invention discloses a distance measuring system for cable laying distance measurement. The distance measuring system comprises a laser distance measuring instrument, multi-angle rotating mirrors and a reflector, wherein the laser distance measuring instrument, the multi-angle rotating mirrors and the reflector are all arranged in a cable shaft; the laser distance measuring instrument is arranged at one end of a distance measurement path below the cable shaft, and the reflector is arranged at the other end of the distance measurement path; in the distance measurement path, the multi-angle rotating mirrors are arranged; laser emitted by the laser distance measuring instrument enters the reflector after being sequentially reflected by the multi-angle rotating mirrors and then is sequentially reflected by the multi-angle rotating mirrors back to the laser distance measuring instrument; the laser distance measuring instrument comprises a single-chip microcomputer, a distance measurement display module, a temperature detecting module, an alarm module, a driving circuit, a laser transmitting probe, a laser receiving probe and a signal processing circuit. The distance measuring system for cable laying distance measurement has the advantages of the capability of measuring nonlinear distance, realization of the distance measurement of lines with turning points, improvement on convenience in cable laying and the like.

The present invention provides a monocular ranging method based on a plane mirror. The steps of the embodiment of the present invention include: Step S1: Calibrate the main optical axis and internal parameters of the camera; Step S2: Install a plane mirror on one side of the camera lens; Step S3 : using a camera installed with a plane mirror to collect the image information of the real object of measurement and the image information of the virtual image of the measurement target in the plane mirror; step S4: calculating the distance between the camera and the measurement target. The ranging method adopted in the present invention has the advantages of simple operation, simple and easy-to-understand calculation process, and high accuracy of ranging results.

The invention discloses a line single-phase earthing fault single-end ranging method realized by utilizing voltage drop imaginary part characteristics. The method utilizes the fault phase negative sequence voltage and the transmission line positive sequence impedance per unit length to calculate the single-phase earthing fault point voltage phase angle, and further calculate an additional fault distance caused by a transition resistance, and the imaginary part of the ratio of the fault phase voltage to the zero sequence compensating current divides the imaginary part of the transmission line positive sequence impedance per unit length and then subtracts the additional fault distance to obtain a fault distance between the transmission line protection mounting part and the single-phase earthing fault point. The method provided by the invention overcomes the impact defects of the transition resistance and load current on single-end fault ranging precision, the ranging precision is high when the transmission line has a single-phase high resistance earthing fault, the ranging principle is simple, the program is easily realized, the fault distance is directly calculated without using a search algorithm, the ranging speed is quick, and the real-time is strong.

The invention discloses a line single-phase earth fault single-terminal location method implemented by the aid of zero-sequence voltage distribution characteristics. The line single-phase earth fault single-terminal location method includes sequentially computing an absolute value of the difference between an amplitude value of an equivalent zero-sequence voltage of each point on a power transmission line and an amplitude value of a zero-sequence voltage of the point by the aid of a one-dimensional search process and a zero-sequence voltage, a zero-sequence current, fault-phase negative-sequence voltages and fault-phase negative-sequence currents at a power transmission line protection mounting position until computation is performed on all points in the total length of the power transmission line; selecting the distance from the power transmission line protection mounting position to the point corresponding to the minimum absolute value of the difference between the amplitude value of the equivalent zero-sequence voltage of the point and the amplitude value of the zero-sequence voltage of the point as the fault distance. The line single-phase earth fault single-terminal location method has the advantages that power transmission line single-phase earth fault single-terminal location is implemented by the aid of the distribution characteristics of the zero-sequence voltages along the power transmission line, influence of transition resistance, fault positions and load currents on the location precision is eliminated in principle, and the location precision is high.

The invention discloses an additional fault distance impact resistant line single-phase earthing fault single-end ranging method, which comprises the following steps of firstly, measuring fault phase voltage, fault phase negative sequence current, fault phase current and zero sequence current at a protection mounting part of a transmission line to be used as an input quantity; utilizing fault phase electrical quantity to calculate an additional fault distance caused by a transition resistance, and subtracting the additional fault distance caused by the transition resistance from the ratio of fault phase voltage to transmission line voltage drop per unit length to obtain the fault distance between the transmission line protection mounting part and a single-phase earthing fault point. The method provided by the invention overcomes the impact defects of the transition resistance and load current on single-end fault ranging precision, the ranging precision is high when the transmission line has a single-phase high resistance earthing fault, the ranging principle is simple, the program is easily realized, the fault distance is directly calculated without using a search algorithm, the ranging speed is quick, and the real-timeness is strong.

The invention discloses a nonsynchronous fault range-finding method for a double-circuit line, comprising series compensation, on the same tower, and the method comprises the steps: employing a six-sequence component method for decoupling for each sub-algorithm, and eliminating a series compensation voltage at a side nearby a fault and series compensation currents at two sides in a transmission equation according to the characteristics that the voltages, deduced from two sides, of a fault point are equal and the currents at two sides of a series compensation device meet the Kirchhoff's Current Law; constructing a fault positioning function through employing the pure resistance of a transition resistor at the fault point when the double-circuit line on the same tower comprises the series compensation; inputting double-end data into an M-side sub-algorithm and an N-side sub-algorithm at the same time for calculation, and directly achieving the precise positioning of a fault without the discrimination of a fault section. The method is applicable to all types of faults, does not need to carry out synchronous sampling, is independent of a series compensation device model, is not affected by MOV nonlinearity, does not need to know the position of the fault point relative to the series compensation in advance, is simple in range-finding principle, just needs to carry out the one-dimensional search of the fault distance, and does not have a problem of false root discrimination.

The invention discloses a method for realizing line single-phase earth fault single-terminal fault locating by using a real part of voltage drop along a line. The method comprises the following steps of: calculating the real part of the voltage drop from a power transmission line protection installation part to a single-phase earth fault point by using fault phase electrical capacity, and dividing the real part of the voltage drop from the line protection installation part to the single-phase earth fault point by a real part of voltage drop of a power transmission line per unit length to obtain a fault distance. The method solves the problem that transition resistance and load current influence single-phase earth fault single-terminal fault locating accuracy; when single-phase high-resistance earth faults of the power transmission line occur, high fault locating accuracy can be achieved, the fault locating principle is simple, and the program is easy to realize; and the fault distance can be calculated under the condition that a search algorithm is not needed to be adopted; the fault locating speed is high; and strong real-time performance is guaranteed.

The invention discloses a method of achieving interphase short circuit fault distance measurement of a line by means of single-end electric quantities. The method includes measuring fault interphase voltage, fault interphase currents and fault interphase negative-sequence currents on a protective installation portion of a power transmission line, calculating an imaginary part of a ratio of the fault interphase voltage and the fault interphase negative-sequence currents, calculating an imaginary part of a ratio of voltage drop of the power transmission line per unit length and the fault interphase negative-sequence currents, dividing the imaginary part of the ratio of the voltage drop of the power transmission line per unit length and the fault interphase negative-sequence currents by the imaginary part of the ratio of the fault interphase voltage and the fault interphase negative-sequence currents, and obtaining a fault distance from the protective installation portion of the power transmission line to an interphase short circuit fault point. The method achieves precise measurement of the interphase short circuit fault distance of the power transmission line by means of the single-end electric quantities, and eliminates influences of transition resistance and load currents on measurement precision of the fault distance. Distance measuring principles are simple, programs are easy to achieve, operation amount is little, the distance measuring speed is high, and instantaneity is strong.

The invention discloses a circuit interphase fault single-terminal location method capable of preventing additional fault location influence. According to the method, the fault interphase electrical capacity at the relay location of a transmission line is adopted to calculate additional fault location aroused by transitional resistance, and the ratio of the fault interphase voltage and the voltage drop of the transmission line per unit length subtracts the additional fault location aroused by the transitional resistance to obtain the fault location from the relay location of the transmission line to the interphase short circuit fault point. The method provided by the invention solves the problem that the transitional resistance and the load current influence the single-terminal fault location precision, has high location precision and simple location principle, achieves easy program implementation without directly calculating the fault location through the search algorithm, and is high in location speed and strong in real-time performance.

The invention discloses a line single-phase earth fault single-terminal ranging method implemented by the aid of sequence components. The line single-phase earth fault single-terminal ranging method includes converting negative-sequence voltages of a power transmission line single-phase earth fault point into an equivalent zero-sequence voltage; accurately computing the fault distance according to a fault characteristic that a certain zero-sequence voltage of a power transmission line single-phase earth fault point is equal to the equivalent zero-sequence voltage so as to implement power transmission line single-phase earth fault single-terminal ranging. The line single-phase earth fault single-terminal ranging method has the advantages that the power transmission line single-phase earth fault single-terminal ranging is implemented according to distribution characteristics of the zero-sequence voltages along a power transmission line, influence of transition resistance on the ranging precision is eliminated in principle, influence of load currents and fault positions is prevented, and the ranging precision is high; a ranging principle of the method is simple, programs are easy to implement, the fault distance does not need to be directly computed by a search algorithm, and the method is high in ranging speed and instantaneity.

The invention discloses a method for achieving circuit phase-to-phase fault single-ended distance measurement by means of voltage drop imaginary part characteristics. According to the method, fault phase-to-phase negative sequence voltage and unit length power transmission line positive sequence impedance are used for calculating a voltage phase angle of a phase-to-phase short-circuit fault point, therefore, an additional fault distance caused by transition resistance is calculated, and an imaginary part of a specific value of fault phase-to-phase voltage and a fault phase-to-phase current is used for dividing an imaginary part of the unit length power transmission line positive sequence impedance and then subtracting the additional fault distance to obtain a fault distance between the protection installation position of a power transmission line and the phase-to-phase short-circuit fault point. According to the method for achieving the circuit phase-to-phase fault single-ended distance measurement by means of the voltage drop imaginary part characteristics, the problem that the transition resistance and a load current have an influence on accuracy of the single-ended fault distance measurement is solved, when a power transmission line phase-to-phase high-resistance short-circuit fault exists, the accuracy of the distance measurement is quite high, the principle of the distance measurement is simple, a program is easy to achieve, the fault distance is directly calculated without the requirement for adopting a search algorithm, the speed of the distance measurement is high, and real-time performance is strong.

The invention discloses a method for ranging a single-phase earth fault of a line by using single-end electric quantity. The method comprises the steps of measuring the fault phase voltage, the fault phase negative sequence current, the fault phase current and the zero sequence current in a transmission line protection mounting location; calculating an imaginary part of the ratio between the fault phase voltage and the fault phase negative sequence current; calculating an imaginary part of the ratio between potential drop per unit length of the transmission line and the fault phase negative sequence current; and dividing the imaginary part of the ratio between the fault phase voltage and the fault phase negative sequence current by the imaginary part of the ratio between the potential drop per unit length of the transmission line and the fault phase negative sequence current to obtain the fault distance from the transmission line protection mounting location to the single-phase earth fault point. The method uses the single-end electric quantity to achieve accurate measurement of the single-phase earth fault distance of the transmission line, overcomes the influence of transition resistance and load current on the fault distance measuring accuracy, the ranging principle is simple, the program is easy to achieve, and the method has the advantages of small calculation amount, high ranging speed and high real-time performance.

The invention provides a same pole double-circuit hybrid transmission line fault range finding method taking regard of influence of distributed capacitance is characterized in that the same pole double-circuit hybrid transmission line is connected between an M side and an N side of a plant station, and a connecting point between two sections I1 and I2 is T1; an M side power is EM, and an N side power is EN; and then fault range finding is performed by means of analysis through a positive sequence equivalence circuit of the same pole double-circuit hybrid transmission line. The same pole double-circuit hybrid transmission line fault range finding method taking regard of influence of distributed capacitance can realize fault range finding of the double-circuit hybrid line by using the basicline parameters and the current data on both sides, and the line model is more complicated, and so that different fault section lines can be identified, and the same pole double-circuit hybrid transmission line fault range finding method is suitable for long-distance lines of more than 100 kilometers.