Safety Considerations for Evaluating Medium-Voltage Power Electronics

Silicon carbide (SiC) technology continues to improve, which has led to SiC MOSFETs capable of operating at medium voltage (MV) levels greater than 1.7 kV. These devices are currently being evaluated for use in next-generation MV power electronics. However, evaluation of prototype power electronic systems at MV incurs additional operator risks compared to evaluation of low voltage (LV) systems below 1.7 kV. Due to these inherent risks, the power electronics community needs to apply precautions similar to those used as standard practice in the power distribution industry. This paper presents a test environment that is designed to support high-fidelity measurements of MV power electronics while ensuring operator safety. This environment features an enclosed safety cage with interlocks and fault detection circuitry that interfaces to the equipment under test (EUT). This paper provides guidance for designing and deploying testing infrastructure for MV power electronics, including analysis of arc flash risk for MVDC power electronics. Current arc flash safety standards, which are geared towards power distribution systems, offer limited instruction for MVDC power electronics.