Hybrid DC circuit breaker power supply system with load constant voltage self-balancing design

Abstract

Power electronic switches (PES) play a crucial role in transferring and clearing fault currents in hybrid DC circuit breakers. The PES encounters switching transients that require a dependable external power source. Usually, a power supply system utilizes an isolation transformer and many magnetic rings. However, the existence of inconsistent parameters might easily cause an imbalance in load power, which could potentially result in power supply failure for the loads. Therefore, to enhance the reliability of power supply, this study proposes a load constant voltage self-balancing design approach that utilizes feedback circuits to achieve stability and balance in load voltage. At first, two feedback circuits are shown, and the analytical formulas for load active power and load voltage are derived. Moreover, a parameter design methodology is shown for the equivalent circuit of the magnetic rings in the power supply. Additionally, a power supply system is built with 24 V outputs. In conclusion, this study utilizes simulations and tests to assess the effectiveness of the proposed power supply system by analysing its performance during start-up, load power-off, and steady-state operations.