Characterization of High Voltage Power Net in Heavy Duty Fuel Cell Truck with Focus on Current Ripples

Heavy-duty fuel cell trucks (HDFCT) have complex High Voltage (HV) power net architectures. This work focuses on characterization of an entire HDFCT HV power net architecture with the help of a frequency analysis. Since there are several sub inverters with variable switching frequencies connected to a common DC-bus, the whole system becomes complex with respect to control and overlaying effects. Dominant frequencies and currents are analyzed by real measurements at a prototype truck. As the switching of inverters generate current ripples, a simulation model based on impedance measurements and a tool chain to analyze different driving modes of the truck is set up-like acceleration and braking. The impact of these driving modes on the characterized HV power net is explained, and validated in this publication.