Design Enhancement and Analysis of Spring Operated Drive to Use for High Rating Circuit Breaker

Abstract

The circuit-breaker constitutes the last link in the chain of the protection equipment for a power supply system. A circuit breaker is an apparatus in electrical systems that has the capability to, in the shortest possible time, switch from being an ideal conductor to an ideal insulator and vice versa. Hence, the `Drive' used to operate the Circuit Breaker shall have sufficient energy to overcome the said stresses and open or close the circuit breaker in reliable manner maintaining adequate operating times (opening and closing) within permissible limits. For that drive has to follow reference Time-Travel Curve (curve specifying mechanical characteristics like stroke, velocity, damping etc.). The objective of this dissertation is primarily to study the dynamic behavior of the existing drive used to operate the circuit breaker during opening and closing operations. Design of cam and damper is carried out to obtain Time-Travel curve during closing and opening operation. This curve should match the curve of reference drive within particular band limit (+5% band). The analysis of dynamic stresses imposed on different component of the drive during closing and opening operations is performed using Multi-body Dynamics (MD) software-ADAMS and ANSYS. An actual setup and testing is also done at testing lab of ABB ltd to measure practical value of its performance parameter and measuring its fatigue life for 2,000 and 10,000 cycle subsequently. As outcomes of above project work is to make modification in circuit breaker drive to obtain performance parameters by analytical simulation and comparing it to experimental results. After comparing this result perform certification test of operating mechanism.