Design And Implement Of Arc-suppression Coil Integrated System With Auto-tracking And Auto-compensating

Neutral-point grounding systems are various in powergrid system.Different countries and regions,different power conditions have different options.To neutral-point non-grounding system or arc suppression coil grounding system,fault current is small when single phase grounding happened.So they are called small current grounding system.The small current grounding system can commit for 2 hours after single phase grounding without trip immediately,so it is widely adopted in China for6-66 kV medium voltage powergrid.But small current grounding system should solve problems such as capacitive current compensation,over-voltage reduction,arc suppression,fault feeder determination when single phase grounding fault happened.This is an important research subject in power system relay protection.Firstly,by comparison of advantage and disadvantage of different neutral-point grounding methods,by analysis of self-adaption conditions,status and development trends in domestic and foreigner countries,the reach subject and design orientation has been decided: complete set design of auto-tracking compensation arc suppression coil system.Secondly,by analysis of application status and technical development trend of arc suppression coil capacitive current compensation and single phase grounding discrimination to small current grounding system,the general design proposal has been determined.The complete set of auto-tracking compensation arc suppression coil is composed of grounding transformer,tap-changing arc suppression coil,damping resistance panel and controller.The pre-compensation method has function of capacitive current measurement,tap position changing,auto-compensation,grounding feeder discrimination and tripping.Finally,according to the overall proposal,each component is designed respectively,especially detailed design to the hardware and software of the controller.The controller is based on the ARM kernel and takes 32-bit high performance microcontroller STM32F103 ZE as the core which has rich peripheral unit.Finally realize the function of capacitive current measurement,tap position changing,auto-compensation,fault feeder discrimination and tripping,etc by the analyze and study of various algorithms comprehensively and the design of hardware and software of IO interface circuit,AD sampling circuit,LCD display and communication interface circuit.Then complete the design and make the preliminary prototype,and is verified by experiment.