Design of a residual current circuit breaker IC with anti-interference technique

摘要

Residual current circuit breakers (RCCB) is the equipment which protect human body from an electric shock, there is close relation between RCCB and human safety. However, shortages still exist. Current RCCB tend to cause nuisance tripping due to their sensitive reaction to the interference signal in the actual power grid. So, the RCCB cannot work at the crucial moment effectively. This paper analyzes the impact to the RCCB from the general interference signal and induced interference signal in power grid, and this paper also introduces a new technique—10 ms non-actuating time technique, which is used to stand aside the interference signal. This technique with delay time protection and other anti-interference technique are integrated into a special RCCB IC chip, which is fabricated in a mixed-signal 0.5 µm CMOS process in CSMC. The test results verify great improvement in RCCB performance. Additionally, this paper analyzes the disadvantage of the active national standard referring to RCCB in China and presents some suggestions for the improvement.