Passive Methods Limiting Leakage Current in Metal-Oxide Varistor Used as Voltage Clamping Circuit in Low Voltage DC Semiconductor Circuit-Breakers

Abstract:
In this work, two passive methods are proposed to limit the leakage current of metal-oxide varistor (MOV) used as the most common voltage clamping circuit in semiconductor circuit-breakers (SCCBs) known as hybrid and solid-state circuit breakers during standby operation defined in the draft standard for SCCBs. The first method is placing MOV in series with silicon bidirectional SYDAC (Silicon Thyristor for Alternating Current). The second connects MOV in series with GDT (Gas Discharge Tube). Both methods are characterized by experiments and compared with each other, and other passive methods. Results enable utilization of low cost-high energy dissipation capable of MOV with limited leakage current and low breakdown voltage semiconductor switches in SCCBs used for low voltage DC applications enabling standby operation of breakers.