1994 Volume 114 Issue 7-8 Pages 800-806
The power capacitor and the AC filter are used for the reliable supply of electric power. For the protection of the power capacitor system, the over-load relay must be very accurate, because the operating voltage in power system is nearly the limited level of the power capacitor. For the protection of the AC filter system, the effective value must be detected from the filtercurrent which is mixed of fundamental and harmonics. So, we developed and produced the relay systems using new algorithms, high rate sampling, digital filter, R.M. S. calculation. On this paper, we report the characteristic of the protections and the algorithms.