Method and apparatus to limit the transient peak of passivefilters in circuit breakers using air core sensors by capacitor compensation

摘要

A method and an apparatus to limit the transient peak of Passive Filters in Circuit Breakers using Air Core Sensors by capacitor compensation are disclosed. In one implementation, the only change that is performed is the addition of a Capacitor C7 401, in the non-inverting terminal of the operational Amplifier. The Passive integrator circuit lies in the inverting section of the Operational amplifier. By introducing a capacitor in the non- inverting leg, we purposefully create another charging curve, which is a replica of the curve generated by the charging of capacitor C8 in the Passive integrator section. When both the capacitor signals are fed into the operational amplifier, by the inherent property of the Operational Amplifier to bias the inputs received from the inverting terminal and non- inverting terminal, the charging curve formed by capacitor C7 tends to nullify the initial peak formed by C8 in the passive integrator section.