| Resistive current and harmonic current components of ground residual currentincrease with the increases of city distribution network capacity,city distributionnetwork nonlinear load and cable line. Full current compensation arc suppression coilcan solve the problem of residual current compensation, also can suppress thearc-earthing over-voltage effectively when the network is grounded through anarc-extinguishing coil. It can ensure power supply security and reliability indistribution network.The dissertation carries out research on key technologies on fullcompensation crc suppression coil.For getting practical data of ground residual current, dozens of power systemcapacitive current were tested.Grounding experimentals of XieQiao coal mine wereresearched as an example,experimental results and analysis conclusion are given asthe research foundation of the following chapters. Existing research of groundresidual current has limitation, so this dissertation presents that the single phase earthfault system for double harmonic sources need to be analyzed,the influences ofharmonic source types and fault point position on harmonic voltage and current wereanalyzed theoretically. The technical problems of ground residual currentcompensation are residual current compensation is dependent on earthed fault feederdetection results and estimation of the parameters excessively,the system unstableproblem bought by the use of active converter device. Detection method taked zerosequence voltage as analysis object can solve the problems.Accurate modeling of single phase earth fault system is a important step forachieving zero sequence voltage detection. Dynamic phasor model method of fullcurrent compensation arc suppression coil is porposed,it can change to react the needsof analysis,also can select a certain signal frequency for analysing on purpose. Thismodeling method is available for the condition that the transient component of groundfault current is rich,also can be applied in full current compensation arc suppressioncoil system contained power electronic equipment,the simulation results prove thefeasibility. Existing research of transient state analysis lacked some contents includedthe transient signal characteristics,extraction and utilization of fault informationdata.In this dissertation, transient fault signals are analysed in frequency domain,andthe system are simulated and modeled, for getting distribution law of transient voltageand current in different frequency bands. The essential structure of master-slave full current compensation arc suppressioncoil is the parallel operation of traditional arc suppression coil and inverter.In view ofthe different kinds of master arc suppression coil, a master-slave control strategies offull current compensation arc suppression coil is proposed. A passivity-based controlmethod of full current compensation arc suppression coil based on dynamic phasormodels was proposed. This method achieves zero sequence voltage detection, it cansecure a stable from a global perspective, it also has fast transient response, simpleform and a good ability of robustness. Simulation and experiment results show thatthis method decreases the amplitude of residual current effectively.The need for distributing installation of master compensation arc suppression andadding of slave arc suppression coil are described.The proposed structure of fullcurrent compensation arc suppression coil is calculated for distributing installation,electrical properties of it are analyzed,and system evaluation is given. Then,simulation comparison experiments of system under different distributing installationsituations are conducted,simulation results show that distributing installation isbeneficial to decrease ground residual current.Finally, a software which can assess theoperation condition of isolated grid is presented under the environment of Matlab.This software can imitate isolated grid system included varieties of distributedgeneration equipments dynamically, and distribute and plan the energy of isolatedgrid.Based on the concept of full current compensation arc suppression coil useddistributing installation,software design and hardware design of full currentcompensation arc suppression coil device applied to the environment of isolated gridare shown. |
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