The goal of this work is to present a method for controlled switching of transmission line circuit-breakers and to develop a device to control the closing of its contacts. The switching strategy consists on finding a suitable circuit breaker making instant and it is based on a very simple zero crossing algorithm. For the first time, the method is evaluated in real time using a RTDS TM (Real Time Digital Simulator) and its implementation is accomplished in two ways: first, it is used the CBuilder tool of the RTDS TM and second, a DSP (Digital Signal Processor) is used as a control device. Data from the CHESF power system are used to produce case studies. Different line switching events are analyzed: closing and re-closing of shunt compensated lines taking into account trapped charge effects. The performance of the proposed method is compared to the pre-insertion resistors method. The simulations attest the efficiency of the controlled switching, which is economically more attractive.
Controlled Switching; DSP; RTDS TM; Switching Overvoltages; Transmission Lines