On the improvement of SOE tester time precision

In this paper the usual problems of Sequence of Events (SOE) and SOE testers are analyzed, the key factors affecting SOE tester's time precision are studied and the methods to improve time precision of SOE tester are proposed. A portable SOE tester based on a discrete model is presented accordingly. The SOE meter is composed of host and slave computers with the CPU of C8051F121. Communications between host and slave computers are achieved by RS-485 technology. Experiments show that time precision of the tester is high enough to meet the demands of all kinds of SOE. The SOE tester is essential equipment for the safe operation of the power plant.