A PCB Integrated Differential Rogowski Coil for Non-Intrusive Current Measurement Featuring High Bandwidth and dv/dt Immunity

Abstract

In the development of next-generation power modules for electric vehicles, demands for high efficiency, reliability, low cost, high power density and therefore small size are of major importance. A promising approach is the embedding of power semiconductor devices into a printed circuit board (PCB), as investigated by the HI-LEVEL project. This paper deals with the research, design and experimental verification of a current sensor based on the principle of a Rogowski coil, which is integrated into a PCB, so that it can measure the device current of the embedded power semiconductor devices. As switched-mode currents are to be measured, the dynamics of the current sensor were of major concern. Moreover, as large voltage gradients caused by the semiconductor devices inject parasitic capacitive currents into the coil, a differential measurement approach was selected for cancelling out disturbances caused by capacitive coupling.