Ultra-Wideband Contactless Current Sensors for Power Electronics Applications

Enhanced power density factors can be achieved in the new generation of power electronics by utilizing wide-bandgap semiconductor switching devices with higher switching speeds and lower losses. These characteristics make high-frequency switching (wide-bandgap-based) power converters superior to silicon-based converters in several respects, including better size, weight, efficiency, and power density than silicon-based converters. The design and manufacturing of these power converters have significantly different requirements compared to traditional converters, making it challenging to integrate components and sensors with tighter tolerances. Wideband current sensors are also necessary for diagnosing, monitoring, and controlling wide-bandgap power converters. Speed is not the only concern when developing power converter layouts; size and invasiveness are also significant considerations. Several properties, such as size, speed, noise immunity, accuracy, linearity, capacity, isolation, and non-invasiveness, are required for the next generation of power converters that cannot be achieved with currently available commercial current sensors. Due to size and cost constraints, these converters cannot be equipped with current probes either. Therefore, non-invasive, ultrafast, high-capacity, switch noise-immune sensors are required by wide-bandgap-based power electronics converters.
In this thesis, comprehensive studies of single-scheme and hybrid current sensors are presented as well as issues regarding their integration into power electronics. The present study illustrates that there is no specific method of current sensing that can combine all the required sensing factors at once. The results of a feasibility study have been used to develop guidelines for the design of current sensors that provide high-quality output signals and are readily applicable to the next generation of power converters. Frequency response verification using vector network analyzers and also different types of current waveform comparisons will prove the functionality of proposed light-size and low-cost sensing solutions.