Development of a VCE-Measurement Board for Medium-Voltage Modular Multilevel Converter

Abstract:
Modular multilevel converter (MMC) is one of the most attractive power converter for medium-voltage dc (MVdc) due to the flexibility to be connected in a wide dc voltage range. Such feature is achieved by employing a high number of power semiconductor devices and poses a challenge for the real-time thermal monitoring of each device. Temperature-dependent parameters can be used for the condition monitoring as an alternative to the invasive module-integrated physical sensor. In this work, a VCE-measurement board is developed aiming to estimate the junction temperature of the power devices. Moreover, each semiconductor device has its own parameterization in the presented method to reduce the device parameter deviation. In addition, the modularity feature of the MMC is preserved since the developed measurement board is readily connected to the gate drivers. Finally, the performance of the developed VCE-measurement board is evaluated by experimental results considering five different power modules.