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

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 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 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 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 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 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.