An advanced electrical approach to gauge rotor position sensors for optimizing electric drive train systems

This paper introduces a novel, advanced approach to evaluate and benchmark different types of state-of-the-art rotor position sensors for electric drive train systems. It has been well recognized that the reduction of overall emissions produced by transportation systems plays an important role so that cars containing an electrical pow- ertrain are getting more and more widespread in different markets worldwide. Research nowadays is concerned to develop more efficient electrified powertrain systems, that have the potential to contribute to a reduction of CO2- and harmful emissions. For an efficient and optimized motor control it is crucial to measure the exact rotor angular position and speed of the electric machine. The state-of-the-art rotor position sensor technology used in electric drive trains represents the resolver, which is the investigated sensor type in this research work. To find the most suitable resolver type for a specific powertrain application and so to optimize the overall propulsion control, var- ious kinds of multispeed resolvers from different manufacturers are gauged regarding electrical parameters, that are not defined by the producer by default. Electrical measurement principles are applied e.g., to determine the sensor’s input and output impedance, establish the transfer function based on the transformer equivalent circuit, specify the phase delay and the temperature behavior of the electrical characteristic. These evaluations are done on a unique, highly accurate sensor test bench and extend the state-of-the-art rotor position sensor characteriza- tion [1, 2, 3, 4]. The mentioned test bench enables to gauge various kinds of sensors under different mechanical-, speed- and temperature conditions. The new, advanced approach enables a detailed determination of all relevant sensor parameters that are needed to operate an efficient motor control. Furthermore, the methods supports de- tailed benchmark with the target to determine the most accurate resolver. In addition, the resulting knowledge of the sensor parameters enables further innovative investigations e.g., to determine indirect measured quantities.