Modeling and control of fault tolerant drive topologies for electric vehicle applications

Abstract

In this paper, fault tolerant topologies based on permanent magnet synchronous machines (PMSM) are presented. A numerical model for the simulation of the operational behaviour under normal and fault conditions is developed and validated by test bench measurements. For different fault tolerant topologies, control strategies for normal and post-fault operation are presented and validated by measurements and simulations. In post-fault operation, the presented control-strategies allow the compensation of braking torques and to avoid overvoltages at the machine terminals. In normal operation, the additional degrees of freedom are utilized to improve operational behaviour in various aspects

Implementation and Test of a Fault-Tolerant Wheel Hub Drive System for an Electric Vehicle

“…1). By adjusting the control strategy, unwanted braking torques can be compensated, and the drive system can be protected against overvoltage when a fault occurs [10]. In the following subsections, the results of the appropriate control methods are presented for the two considered topologies.~p …”

“…However, a higher current is needed than under strategy 1 to compensate the occurring braking torque in the field weakening range. Therefore, if the active short circuit can be switched, strategy 1 is preferable for error handling [10]. Fig.…”

“…The factor 1.15 results from the zero voltage injection (space vector modulation) which is possible in Y-topologies to increase the maximum phase voltage by the factor 1.15. In order to compensate for that, the H-topologies allow for zero sequence sequence injection in the current, leading to reduced thermal stress in standstill operation [10].…”