A Hybrid Solid State Circuit Breaker for DC System using Coupled Inductor

Relative to solid-state circuit breakers that utilizes IGBTs and MOSFETs, the thyristor-based circuit breakers offer greater capacity and affordability, making them suitable for use as solid state breaker for higher power DC supply system. Nonetheless, recently the thyristor-based circuit breakers faced limitations towards reliably interrupting of fault currents during high resistance faults. To address this, a new and efficient circuit breaker is introduced in this paper, designed to accomplish automatic and controllable turn-off operations. The fault current through a coupled inductor is used to increase the capacitor voltage which turns-off the main switch. A fast acting switch is utilized to reduce the time of operation. This proposed configuration amalgamates the benefits of high efficiency, rapid responsiveness, and dependability. The effectiveness of the proposed circuit breaker is verified through MATLAB/SIMULINK simulation at a power rating of 25 kW DC system.

I. Introduction

Degradation of the environment caused by fossil fuel-based generation has led to the development of renewable energy sources. The renewable such as solar PV generates DC in its raw form. To condition power, these sources require various converters to be integrated into the grid in order to smooth out the voltage and current fluctuations caused by their intermittent nature. However, the efficiency of the system has decreased due to DC-DC and DC-AC conversion, as well as the number of conversion stages. Because of their lower losses and greater controllability, direct current (DC) systems have recently attracted attention for the applications in low and medium voltage applications [1].