Research On On Full Compensation Arc Suppression Coil Based On Therist Control Technique

With the blossom of modern science and technology, the scale of electrical power system is developing and expanding in an incredible speed. In the power system, maintaining a safe and reliable operation especially in the distribution system plays a pivotal role. In recent years, distribution network cables are more frequently used and the overhead lines are constructed longer than ever, making the line-to-ground capacitive current extremely large once grounding fault occurs. Grounding fault can be dangerous. On the one hand, it increases the risks of arc grounding overvoltage. On the other hand, large capacitive current can directly influents the system reliability and safety if the fault can not be removed in short time. Under this circumstance, the resonant grounding system is introduced which can effectively lower the negative impacts caused by single line-to ground faults and improve the system stability. Full compensation to the grounding capacitive current can reduce the arc restrike and prevent arc grounding overvoltage. Therefore, it is seriously significant to find a kind of arc suppression coil which can fully compensate the fault current in a quick and effective way, to ensure a more reliable and stable distribution system.This thesis is based on a cooperated project with enterprises. Firstly, I look into the basic compensation principles of the resonant system and the methods to measure the capacitive current when grounding fault occurs, proposing the necessity of using full compensation arc suppression coil in the grounding system. Next, from a theoretical point of view, I analyze the merits and demerits of different kinds of arc suppression coils controlled by thyristor. Then, a Matlab simulation system is built to simulate the effect of the full compensation coil when single line-to ground fault happens, thus verifying the compensation characteristics and analyzing the active component and harmonic waves caused by the thyristor switches. Finally, based on a real substation as a prototype, I use the existing equipments to build a hardware laboratory model to simulate the compensation effect by two kinds of arc suppression coils when something happens to the substation (grounding faults), with the comparison of the two types.This thesis stars from a theoretical analysis, followed by simulation studies and the hardware experiments. In this topic, I deeply research the compensation characters of the thyristor-controlled arc suppression coil. The results can be an effective basis both in the choice of on-site arc suppression coils and the related control technology.