Fault Line Detection Based On Similarity Theory In Active Full Compensation Arc Suppression Device

Distribution network in our country usually adopt neutral point grounding or via arc suppression coil grounding of the small current grounding operation mode. Single-phase grounding in power distribution network, is the highest electrical fault in the probability of occurrence. when Single-phase grounding happens, the system would continue to run for two hours rather than immediately be outage. However, if the trouble was not be precluded in allowing time, it will raise larger accident. In recent years, a lot of 10 kV and 6kV power grid is gradually transformed into arc suppression coil grounding method. At present, a variety of line selection method based on the arc suppression coil grounding mode has been concerned by scholars both at home and abroad. Due to the small fault current and other complexity reasons of single-phase grounding, Some traditional methods have some defects. So the research of high reliability of line selection methods has important theoretical significance and practical value to the security of distribution network.Because of the less available characteristic quantity and unreliable fault feature of arc suppression coil grounding fault line selection, this paper presents a similarity line selection method based on the control device of active full compensation arc suppression. The following work has been done:First, a detailed theoretical analysis of the steady-state characteristics and transient characteristics of single-phase earth fault occurs in the small current grounding system.Second, the system uses a new type of active full compensation arc suppression method, which solves the problem of slow dynamic response and large volume of the traditional arc suppression coil.Third, the similarity algorithm is introduced to determine the fault line selection, the fault line selection algorithm is proposed. When single-phase earth fault occurs, the active full compensation arc suppression device is fully compensated at the system neutral point. Make use of the big difference of zero sequence current curves similarity between faulty line and non-faulty line to identify fault line in compensating state.Fourth, use MATLAB simulate a model of single-phase earth fault of non-grounded neutral system controlled by active full compensation arc suppression. Use similarity matching algorithm program to verify different fault line, different grounding resistance, different fault location and so on. The results show the veracity of this algorithm of line selection.Fifth, Simulation of traditional arc suppression coil grounding system in MATLAB. Simulation proves that the active full compensation arc suppression control device of similarity method of line selection without affecting the compensation quickness is more rapid than traditional arc suppression coil system.Sixth, design a set of active full compensation device based on PWM technology. The device was composed of the system bus, active inventer and control system. Provide the research of active full compensation arc suppression coil fault line selection with a hardware platform, on which a basic fault line selection is conducted.