A Research On 110KV Transmission Line Digital Protection

Protective relay is the one of devices to response the fault and abnormal of electric power system to send out signals to trip CB. With the expansion of the power system and the consumer higher requirement for quality of power energy, the protection relay's criteria must be improved greatly and developed to satisfy the higher requirement.This thesis is the research of 110kV-line computer basesd protection relay. This paper recalled the history, the current development and future blueprint of computer relay protection. In this paper,it proposed the distance relay with positive sequence polarized voltage which will have better fault-direction recognization.Direction recognization also can be effective when three phase fault takes plase because of low-voltage relay introduction. It is also discussed protection algorithm in the thesis.This paper developed a 110kv transmission line computer based protection with its hardware and software designs. The hardware is developed by main chip 80C296 and ADSP2181. The CPU fullfels relay start-up, MMI and communication and the DSP processes relay algorithm and logic functions. The start-up function in the realy is to energize trip relay positive pole of DC power supply. The protection has very high inherent reliability and security. This paper developed the software of the equipment. The software function of each block has be detailedThe prevention the intervention of electric-magnetic is introduced in the relay. Testing proved its accuracy and reliability in principle, algorithm, hardware and software.