Design And Research Of Leakage Protector Chip With Basic Leakage Correction

Residual current circuit breaker(RCCB)is one of the most important components in the distribution grid.It is used to detect whether a short-circuit accident occurs in the grid to determine whether to trip,which is an important role to protect personal safety and prevent electrical fires.However,due to the aging of the circuit and the coupling between the electrical casing and the charged body,there will usually be a long-term leakage current in the circuit.This leakage current will slowly change over time and will not threaten the personal safety,which is called basic leakage.The existence of basic leakage is an important reason for the malfunction of the residual current circuit breakers.The traditional leakage protector does not have the ability to identify the basic leakage,and often uses a fixed trip threshold.When the basic leakage approaches the trip threshold of the protector,the trip margin of the protector will be very small.At this time,even small current fluctuations in the line will cause false trip,which greatly affects the electricity continuity of users.This paper proposes a basic leakage identification strategy for this problem.The strategy uses the characteristic that the basic leakage changes slowly with time as the identification,saves the basic leakage using the delay-update method,uses the difference between the real-time leakage and the basic leakage as the short-circuit basis,realizes the function of the threshold following the basic leakage,greatly improves the tripping reliability of the leakage protector.The innovations of this paper are as follows:1.In the past,the idea of researching leakage detection chips mainly focused on how to identify the false trips caused by various interference waves and electromagnetic wave signals input into the power grid.The focus of this topic is to increase the consideration of false trips caused by basic leakage and basic leakage.The concept of the proposed has a reference for the formulation of future standards for leakage protectors.2.Through the dynamic adjustment strategy of the leakage trip threshold,the functions of basic leakage detection,identification,storage,and elimination are successfully realized,and the anti-interference ability of the leakage protector is improved.3.An anti-pulse interference peak detection circuit is innovatively proposed.The peak detection circuit can be used for peak detection of power frequency voltage or current signals and is not easily interfered by pulse signals.