468 results about "Shunt reactor" patented technology

The invention relates to a movable low-voltage ride-through testing device for a wind generating set. The device is connected between a tested wind generating set and an electric network in series, uses an impedance voltage-dividing type and a vehicle container structure, and tests the low-voltage ride-through performance of the wind generating set through analog voltage sag fault; a main connecting wire of the device consists of a serial reactor group, a parallel reactor group and a circuit breaker; the serial reactor group and the parallel reactor group both consist of at least one adjustable reactor; the impedance voltage-dividing ratio can be changed by regulating the impedance value of each adjustable reactor and / or the connecting manner of each adjustable reactor so as to change the voltage sag depth of testing points; and once recovery or a step recovery of the voltage sag can be implemented according to the system requirements. The device can complete the low-voltage ride-through testing experiments for various wind generating sets having a maximum rated capacity of 6 MW, and meet the requirements to the low-voltage ride-through testing experiment in wind electric network integrations in states in Europe and America and Technical Rule for Connecting Wind Farm to Power Networks.

The invention relates to the field of power transmission line relay protection of a power system, and discloses a quick identification method for a permanent fault before single-phase reclosing of a power transmission line. At least one end of the power transmission line is provided with a three-phase parallel reactor and a neutral-point small reactor. The method comprises the following steps of: firstly, acquiring real-time current iLphi(t) of the three-phase parallel reactor, and performing single-phase fault identification and tripping state determination; secondly, disconnecting a least square fitting model of the current iLphi(t) of the parallel reactor after temporary fault arc blowout of a preset line, and solving a low-frequency free oscillating component initial amplitude IL and a power frequency component amplitude I1 of the current of the disconnected parallel reactor; and finally, performing single-phase fault property judgment according to the permanent fault criteria that IL is less than KkI1 and Kk is equal to 0.1 to 0.3.

A zero-sequence impedance method for judging the turn-to-turn short circuit of parallelly connected reactors is disclosed. The high-end current and voltage and low-end current of said reactors are sampled. After A / D conversion and data processing, the real-time current, voltage and angle are obtained, which are compared cycle by cycle to obtain current variation. If the current variation is greater than a predefined value, disturbance exists in the electric power system. Three phase currents and three phase voltages are respectively added to obtain the zero-sequence current and zero-sequence voltage. The zero-sequence voltage is divided by the zero-sequence current to obtain a zero-sequence impedance. If the zero-sequence meets an equation, said short circuit exists.

A broad-spectrum harmonic filter is developed. This filter is to be connected in series ahead of the load which generates harmonics. This filter basically consists of 3 fixed elements, i.e. a series reactor and a shunt reactor in series with a capacitor. It can function to completely filter out 5th harmonic current in 3 phase systems (or 3rd harmonic current in single phase systems) and to reduce other harmonic components by high percentages say, typically close to 70%. Thus the portions of various harmonics flowing toward the electrical power source can be held within acceptable limits.

This invention is a realizing method of transmitting line unilateral auto-conforming reclosing comprehensive judging evidence, based on voltage evidence, compensation voltage evidence, combination compensation voltage evidence and phase evidence. The characteristics are: if the transmitting line is the instantaneous trouble, the above four evidences judge the trouble character; when the transmitting line has general instantaneous trouble, the voltage evidence judges the trouble character; when the transmitting line occurs low off voltage trouble, the compensation voltage, combination compensation and voltage evidences judge comprehensively, as to the heavy service and long-distance transmitting line or the line with parallel reactor, the phase evidence judges the trouble; if the transmitting line occurs permanent trouble, judge whether carrying out reclosing operation according to the results of comprehensive judgment of the four evidence judging.

The present invention discloses fault range measuring method through single end voltage and current. Said invention first utilizes the end voltage and current to calculate the impedance, if the result is positive, it meaning the protective calculated impedance being greater than the impedance from installation place to reference point, using formula to calculate the real distance, if the result is negative, it meaning the trouble point being the middle place, the reference point should be less than 400k, said method is not influence by circuit distribution capacitance.

The present invention relates to the field of the electric power system electric power transmission line relay protection, especially to a technique of the single-phase self-adapting reclosing with a parallel reactor electric power transmission line, and the invention discloses a method for judging the permanent fault of the electric power transmission line with a parallel reactor. The method adopts the parameter recognizing principal and constructs an identification equation which uses the circular parallel reactor and neutral point small reactor a parameter to be determined basing on the network equation when the instantaneous fault has disappeared. The solving to the inductor parameter is realized by the sound phase voltage, sound phase current, parallel reactor current and neutral point small reactor at this side. According to the least square parameter estimate redundant algorithm the inductor parameter is solved, and the instantaneous fault and permanent fault are discriminated using the comparison between the solved inductor parameter and the actual inductor parameter.

The invention discloses an interturn protection method of a high-voltage shunt reactor based on parameter unbalance detection, which is established on the basis of a time domain parameter model and comprises the following steps: calculating the electrical parameter of each phase under the least square significance by using the electrical quantities at the initial end and the tail end of the high-voltage shunt reactor; and identifying whether the interturn short circuit fault of the high-voltage shunt reactor occurs or not by constructing the comprehensive criterion of the parameter unbalance detection under the condition that the interturn short circuit faults of the three phases of the high-voltage split-phase shunt reactor can not occur simultaneously. The interturn protection method can not be influenced by system oscillation and frequency shift. The method is based on measurement and comparison of equivalent inductance parameters of each phase of the reactor, thus the setting process is simple and convenient, and the sensitivity is higher. Because the interturn protection detects the changes of each phase of the inductance parameters, the influence caused by system operation modes and faults on the basis of the sequence component detecting principle is avoided, and the interturn protection method can automatically adapt to the change of the installation position of a voltage transformer.

The invention discloses a configuration method for reactive power compensation of a wind power plant. The configuration method for reactive power compensation of the wind power plant comprises the following steps that electrical data of the wind power plant are acquired; the maximum capacitive reactive power and the maximum lagging reactive power of the wind power plant are measured according to the electrical data and a preset wind power plant electrical simulation model; the type of a reactive power compensation device is determined and the reactive power compensation capacity of the reactive power compensation device is calculated according to the electrical data, the maximum capacitive reactive power, the maximum lagging reactive power and the reactive power regulation capacity of a draught fan, wherein the reactive power compensation device comprises a parallel reactor, a parallel capacitor and / or an SVA device; the reactive power compensation device with the reactive power compensation capacity is installed and configured on a grid connection point of the wind power plant. The invention further provides a system corresponding to the configuration method. By the adoption of the system, the type and the capacity of reactive power compensation can be determined rapidly, easily and conveniently.

The invention is a turn-to-turn protecting method of high voltage parallel reactor, composed of self-adapting compensatory zero sequence power direction component, zero sequence impedance locking component, failure open component, harmonic locking component and turn-to-turn short-circuit protective starting component with phase current industrial frequency variation quantity brake and floating threshold: (1) adopting the turn-to-turn short-circuit protective starting component using phase current industrial frequency variation quantity brake and floating threshold technique; (2) when short circuit between turns occurs, for the self-adapting compensatory zero sequence power direction component, its zero sequence source is inside the reactor and zero sequence voltage is very small, in order to enhance sensitivity of short-circuit protection between turns, it compensates the zero sequence voltage; (3) the failure open component; (4) the harmonic locking component utilizes the proportional relation between industrial frequency components and other harmonics in current and voltage, and when the proportion exceeds to a certain extent, increases action delay time of short circuit between turns and reduces acting sensitivity of short-circuit protection between turns.

This invention relates to a relay protection method in a power system and discloses a method for realizing circuit differential protection based on the long-line equation computation in a high voltage transmission circuit, which converts the voltage and current tested at the protection mounted place to those of a reference point K in the protection sphere by a method of vector computing long-line equation, in which, the voltage Um and the current Im of end m are voltage UKm and current IKm converted to point K, the current In is converted to point k as voltage Ukn and cutrrent Ikn, if there are parallel reactors, it's needed to deduct the current on it to get I'km and I'kn, then Ikm, Ikn or I'km applied at the reference point and the I'kn is computed in terms of multiple differential formula to judge if there is fault in the region.

The invention provides a method for using a controllable high-voltage shunt reactor to inhibit the sub-synchronous resonance of an electric power system. The shafting tachometry signal of the steam turbine generator unit in the electric power system is used as an input signal, and the shafting torsional oscillation property of the steam turbine generator unit can be discriminated from the input signal after being processed by digital signal algorithm. The method is characterized in that the shafting torsional oscillation property signal is calculated on line with a sub-synchronous resonance control strategy to gain the volume control command of the controllable high-voltage shunt reactor, so as to dynamically adjust the volume of the shunt reactor, thus correspondingly dynamically adjusting the reactive power, voltage, active power and rotating speed of the steam turbine generator unit, realizing the effect of inhibiting the sub-synchronous resonance of the steam turbine generator unit, and the effectiveness of the invention is validated by a numerical simulation aiming at certain planning system.

Negative sequence voltage and current is calculated from phase voltage and phase current of leading out end at high voltage side of reactor. Based on the calculated value of negative sequence voltage and current, steps of determining short circuit between turns is as follows: when short circuit fault between turns occurs, direction of negative sequence power is determined from phase relation between negative sequence voltage and current; determining whether short circuit fault between turns occurs inside district or outside district. The method increases action sensitivity of protection components, and cancels out characteristics of impedance compensation used in traditional protection in homopolar power direction. The invention protects reactor, determines earth fault, and guarantees not false operation. Theoretical analysis and emulation test prove correctness and validity of the new theory for protecting turns of reactor.

This invention relates to the longitudinal difference protection for high-voltage parallel reactors in power system, among which, the ratio brake longitudinal difference property is composed of differential quick-break, ratio brake and high-value ratio property. In order to guarantee the protection of correct operation in the transient state process of extra-high voltage and super-high voltage net, this protection has a reactor air detection function, a secondary circuit gap breakage criterion of TA and TA DC saturation criterion so as to make up of a complete end brake digital high voltage parallel reactor longitudinal protection, among which, the ratio brake applies three-section polygon property, the high voltage ratio applies traditional two-section polygon property, the TA secondary circuit gap breakage applies the method of combining zero-sequence current and a phase current and TA DC saturation criterion applies waveform identification theory helped by harmonic wave analysis.

The invention relates to a magnetic control shunt reactor digital simulation modeling method, which is characterized in that the method comprises a decomposition method of an equivalent magnetic circuit, and according to magnetic circuit laws and circuits laws, the magnetic control shunt reactor module can be equivalent to a plurality of saturated transformers and reactor modules; the invention uses saturated transformers and saturated reactors in prior simulation software and forms a magnetic control shunt reactor simulation module, which has clear principles, easy process and realization, has reliable and accurate module, and can be integrated in to prior simulation software to expand prior simulation functions; the digital simulation modeling method of the invention provides effective means for a steady control method and a transient control method of an inspection system.

The invention relates to an alternating-current controllable paralleling reactor comprising a transformer type main reactor and a step reactor. Wherein, the first coil is the main coil which connects the network directly; the second coil is the control coil outside which a break and a thyristor controller are mounted; the third coil is the compensating coil outside which a filtering compensating unit is mounted; and the transformer type main reactor and the second side-connect step reactor are both mounted in a fuel tank to form the body of controllable reactor. The alternating step controllable single-phase paralleling reactor comprises the body with high resistance, the breaker, the thyristor controller and the central controller, and it has the functions and characters which common reactors do not have, including: simply adjusting, rapid response time, non-harmonic-wave, lower noise, lower vibration, high reliability, lower consumption, and it can separate the harmonic wave to reduce the effect to electrified wire netting. The invention can be used in the electrified wire netting of extra-high voltage and long-distance power transmission.

The invention provides a turn-to-turn starting method of a shunt reactor. A problem to be solved is to improve sensitivity and reliability of a starting element. The method comprises steps as follows: calculating parameters by a microcomputer such as a secondary rated impedance of the main reactance, a theoretical value of secondary rated impedance of a smaller reactance, a three-phase voltage at the line side, a vector value of current and measured impedances of three phases in main reactance of the shunt reactor; determining that there is a turn-to-turn fault when any measured impedance of three phases in main reactance of the shunt reactor is not greater than 0.95 * the secondary rated impedance of the main reactance. Compared with the present technology, the invention greatly improves the sensitivity of starting provided that ensuring starting reliability of the turn-to-turn protection by using a characteristic that the measured impedance of the reactor is substantially constant when the reactor is normal, and the measured impedance thereof is obviously lowered when a turn-to-turn fault happens; when an external fault of reactor happens, the turn-to-turn protection starting element of the shunt reactor does not starts because the measured impedance is unchangeable, and that only starts for the turn-to-turn protection when an internal fault happens.

The invention provides a practical decoupling electromagnetic transient state modeling method for describing the nonlinear magnetic saturation property of a super / extreme-high voltage magnetically controlled shunt reactor (MCSR), comprising the steps of: providing a transient equivalent reactance algorithm on the basis of a dynamic magnetic resistance idea under AC / DC mixed excitation; reflecting the real-time dynamic change property of the saturated equivalent reactance under the condition of the AC / DC mixed excitation; accurately describing the magnetizing and demagnetizing effect of network side AC current on a reversely series-wound DC excitation saturation magnetic circuit in two main magnetic circuits of the super / extreme-high voltage magnetically controlled shunt reactor (MCSR); describing nonlinear magnetic circuit property with arc hyperbolic functions; decoupling a coupling magnetic circuit equation; differencing transient equivalent reactance by an implicit trapezoid integration algorithm with damping; and establishing an electromagnetic transient state model. The invention not only accurately reflects the continuously smooth regulation property of the saturated magnetic circuit of the super / extreme-high voltage magnetically controlled shunt reactor (MCSR) and prevents the numerical oscillation of piecewise linearization algorithm, but also can meet the requirements of real-time / faster-than-real-time simulation computation under the condition of large-range continuous regulation.

The invention relates to the field of power system transmission line relaying protection, in particular to a permanent fault identifying method for the transmission line with collateral reactor. The purpose of this invention is to overcome defects of not effectively using the transmission line with collateral reactor in the present technology. In order to overcome problems in the present technology, the embodiment of this invention is that: a permanent fault identifying method for the transmission line with collateral reactor orderly comprises the following steps: after a single-phase fault is found, the protective device phase-selecting unit confirms the fault phase; configuring the criterion and calculating the action value by using current quantity in the collateral reactor and neutral point small reactor; when the calculated action value is less than the setting value, the fault is identified as instant fault and a superposition valve processes superposition action; when the calculated action value is more than the setting value, the fault is identified as permanent fault and the superposition valve does not process superposition action. This invention has advantages of high identifying precision and reliability.

The invention relates to a flashover detecting method and circuit for the bushing of the excitation winding of a magnetic control shunt reactor. The method of the invention includes the following steps: 1) mounting a circuit sensing element at the point grounding location of an overvoltage protection loop of the magnetic control shunt reactor; 2) judging to be normal when no circuits are detected by the circuit sensing element; 3) judging that the bushing of the excitation winding has a direct earth flashover fault when a circuit is detected by the circuit sensing element. The method can detect the fault circuit at the point grounding location of the overvoltage protection loop through the circuit sensing element no matter the flashover fault happens at any place of the bushing of the excitation winding; therefore, the invention is simple to be collocated; the level requirement on the insulating location is low; the detecting cost is low; the invention has great significance for the industrialization development of the magnetic control shunt reactor.

The invention provides dynamic simulation device and method thereof of a super and extra high voltage controllable magnetic control shunt reactor, wherein the dynamic simulation device is capable of accurately simulating magnetic control shunt reactors with different capacities in 500kV, 750kV and 1,000kV power transmission systems. A simulation body consists of three single-phase magnetic control reactors; each single-phase magnetic control reactor is in a three-column structure; two beside core columns are working iron cores; a main alternating current winding and a direct current control coil are wound on each working iron core; and main alternating current windings on the two iron core columns are connected in parallel and connected to a power grid. Control windings are separated from the main windings so as to ensure the safety and the reliability of the device during work. The main windings are provided with twelve turn-to-turn short circuit taps which can respectively simulate 1-25 percent of turn-to-turn short circuit faults from the high-voltage side and the neutral point side; and the control windings are provided with seven turn-to-turn short circuit taps which can simulate 1-25 percent of turn-to-turn short circuit faults from the neutral point side. The body of the device is provided with a current transformer and a voltage transformer on a primary side, which are used for meeting the requirement for protecting a reactor body in a dynamic simulation test.

The method includes steps: protector of reactor obtains instantaneous values of current and voltage by sampling waveforms of threephase current transformer (TA) at secondary side of high voltage, AC controllable type shunt reactor; dedicated external zero sequence current (ZSC) transformer, initial end of threephase potential transformer (TV); using Fourier algorithm determines complex form of each electric quantity; when external ZSC of winding at secondary side is larger than fixed value, the first time limit acts on bypass breaker on joined secondary side through T1 time delayed exit; the second time limit acts on tripping breaker on primary side through T2 time delayed exit; calculating self generated ZSC and self generated zero sequence voltage at initial end, and when ZSC is larger than a fixed value, then warning signal is sent after 5s time delay ; and when locking conditions are not satisfied, the first time limit acts on bypass breaker through T3 time delayed exit etc.

The invention provides a method using a dynamic analog device for ultrahigh-voltage transformer type graded controllable parallel reactors, which is designed to accurately simulate a dynamic analog device for transformer type graded controllable parallel reactors with different capacities in 500 kV, 750 kV and 1000 kV power transmission systems. The primary side of the analog device body is in a single-phase discrete type, and three phases are connected to form a Y shape; and a primary winding is provided with 12 turn-to-turn fault taps which can respectively simulate 1-25% of turn-to-turn faults from the high-voltage side to the neutral point side. The secondary side of the analog device body is in a single-phase closed connection way, and the tail end is directly grounded. The capacities are divided into 9 grades: 100%, 75%, 62.5%, 56.25%, 46.875%, 37.5%, 31.25%, 18.75% and 15.625%. The primary side and the secondary side of the analog device body are respectively provided with a current transformer and a voltage transformer, thereby being capable of satisfying the demands for reactor body protection in a dynamic analog test. Aiming at the body protection on the ultrahigh-voltage controllable parallel reactors and the line protection on installation of the controllable parallel reactors, the invention provides a dynamic analog test method.

The invention discloses an automatic power-down processing reliability test device and method for intelligent ammeters in an interference environment. The automatic power-down processing reliability test device comprises an automatic test controller, an inductive load switching device and at least two ammeters to be tested, wherein the automatic test controller is computer equipment which automatic testing software is installed in and is provided with a communication interface. The automatic power-down processing reliability test method comprises the following steps: an input power supply inside a switching device is switched off by controlling the inductive load switching device, a power supply of a paralleling reactor inside the switching device is switched off while the ammeters to be tested which are connected to a switching device voltage loop in parallel are powered down, an inductive load switching interference is generated in a simulated mode, and the inductive load switching interference is output to the voltage loop of the ammeters to be tested through a voltage interface; communication with the ammeters to be tested is conducted through an RS485 interface, operating data of the ammeters to be tested before being powered down and operating data of the ammeters to be tested after being powered up again for operation are detected, so that whether power-down processing of the intelligent ammeters to be tested under the inductive load switching interference is normal is judged, an assessment of the power-down processing reliability of the intelligent ammeters under the interference is realized, and faults are prevented from happening.

The invention provides an optimal configuration of a 10 kV power distribution network parallel reactor and a compensation method of the 10 kV power distribution network parallel reactor. The optimal configuration of the 10 kV power distribution network parallel reactor and the compensation method of the 10 kV power distribution network parallel reactor are used for solving the problem that inductive reactive power optimal allocation of resources of insertion of small hydro to power distribution network and controlling switching of the reactive power compensation. The compensation method of the 10 kV power distribution network parallel reactor comprises the following steps: obtaining a voltage drop reactive decoupling formula by means of a decoupling deduction of the voltage drop formula; ensuring reactive decoupling coefficient according to the line reactance per kilometer and the line voltage reference; ensuring an optimal configured compensation point of the 10 kV parallel reactor according to the voltage drop reactive decoupling formula; ensuring and avoiding the capacity of the 10 kV parallel reactor configuration of the upper limit of the node voltage of a trunk line, and ensuring the capacity of a single unit and the number of configured groups of the 10 kV parallel reactor by a reference of a rule that a voltage regulating effect of reactive compensation equipment of a single group of a transformer substation does not exceed 2.5% of the rated voltage; and monitoring the node voltage of the trunk line including the small hydro in real time, and controlling the switching of the 10 kV parallel reactor according to the voltage drop reactive decoupling formula.

The invention discloses a relay protection method of blocking filter mistermination failure. The method comprises the steps that current sampling is carried out on each group of paralleling reactors and a capacitor in a static blocking filter (SBF) by a replay protection device and a current flowing into the whole SBF is sampled; amplitude values of the current of each reactor and the current of the capacitor and the amplitude value of the current flowing into the SBF are calculated by means of the full cycle Fourier numerical filtering algorithm; ratios of the amplitude value of the current of each reactor current and the amplitude value of the current of each capacitor are calculated; and when the amplitude value of the current flowing into the SBF is big enough and the current ratio is beyond a pre-determined scope, an alarming signal or a tripping signal is sent out after a delay and a tripping relay idle contact is output. According to the relay protection method of the blocking filter mistermination failure, only currents of each reactor and the capacitor of the blocking filter and the current flowing into the blocking filter need to be measured, and wiring is simple. The full cycle Fourier algorithm only reflects power frequency weight in electrical quantity. The method is simple and reliable.

The method includes steps: sampling waveforms of current transformer (TA) at primary and secondary sides of high voltage, AC controllable type shunt reactor, protector of reactor obtains instantaneous values of current; using Fourier algorithm determines complex form of each electric quantity; based on TA transformation ratio input from user to calculate balance coefficient automatically, and to output the coefficient for users to check it out; using the balance coefficient to calculate secondary current at secondary side of reactor after compensation of balance; calculating differential current and braking current; based on differential quick break and ratio brake characteristic to determine protection logic of large differential in order to carry out protection action. The method also includes tests of vacancy throw, TA DC saturation, and TA abnormity. The invention protects fault inside the said reactor, especially winding and grounding faults of coil at secondary side.

The invention provides an ultrahigh-voltage power distribution power-frequency overvoltage suppression method. For the power-frequency overvoltage generated by a no-load long-line capacitance effect, asymmetric ground faults and three-phase load shedding (or three-phase tripping), a shunt reactor is selected, the upper and lower limits selected for the reactor are calculated, and the power-frequency overvoltage of an ultrahigh-voltage power distribution system is limited by virtue of the transient state adjustment and the series switching of the controllable reactor; as a result, the stability and safety of ultrahigh-voltage power transmission can be guaranteed.

The invention discloses an offshore wind plant reactive power optimization configuration method considering wind turbine generator reactive power regulation. The method specifically comprises the steps of selecting compensation points and compensation modes according to the capacity and the conveying distance of an offshore wind plant; establishing an offshore wind plant equivalent model, optimizing the compensation capacity and the grouping number of high-voltage shunt reactors according to reactive requirements of the offshore wind plant at different active output levels, and formulating a PDFIG-n table; according to the requirements of offshore wind plant grid connection technical specifications for voltage, optimizing the compensation capacity of an SVG device through dynamic simulation, and ensuring transient voltage stability; and according to the optimized compensation capacity, coordinating and optimizing the reactive power output of the wind turbine generator and a reactive power compensation device by taking static voltage stability and low operation cost as targets and utilizing the reactive power regulation capability of the wind turbine generator. According to the method, the static and transient voltage stability of the offshore wind power plant is considered, the reactive power regulation capability of the wind turbine generator is fully utilized, and the economyand safety of a reactive power configuration scheme are improved.