Topology Simplification and Parameter Design of Z/T/Γ-Source Circuit Breakers

Abstract

Z/T/ <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\Gamma $ </tex-math></inline-formula> -source circuit breakers used in flexible dc distribution systems have been rapidly developed due to their advantages of high speed and low cost. However, the precise model of the circuit breaker is generally a high-order circuit, which is difficult to solve. The lack of simplified topology and parameter design considering system parameters (line inductance, line resistance, and load capacitance) restricts their applications in practical engineering. Therefore, based on the equivalent mathematical model, a simplified topology that can represent Z/T/ <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\Gamma $ </tex-math></inline-formula> -source circuit breakers is proposed and their working principles are revealed in this article. Considering system parameters, the parameters of Z/T/ <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\Gamma $ </tex-math></inline-formula> -source circuit breakers are designed to take care of short circuit fault and step changes in load. Finally, simulation and experiment show that parameters designed by the proposed method can ensure the reliable operation for Z/T/ <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\Gamma $ </tex-math></inline-formula> -source circuit breakers.