Dian Tresna Nugraha

Enhanced Availability of Drivetrain Through Novel Multiphase Permanent-Magnet Machine Drive

This paper deals with a novel multiphase permanent-magnet (PM) machine drive to enhance drivetrain availability in electric traction applications. It describes the development of new winding configurations for six-phase PM brushless machines with 18 slots and eight poles, which eliminate and/or reduce undesirable space harmonics in the stator magnetomotive force. In addition to improved power/torque density and efficiency with a reduction in eddy current loss in rotor PMs and copper loss in end-windings, the developed winding configuration also enhances availability of drivetrain, in a variety of applications requiring a degree of fault tolerance, by employing it as two independent three-phase windings in a six-phase interior-PM machine, which is designed and optimized for a given set of specifications for an electric vehicle, under thermal, electrical, and volumetric constraints. This paper also describes the design and development of a six-phase inverter with independent control for both sets of three-phase windings. The designs of the motor and the inverter are validated by a series of preliminary tests on the prototype machine drive.

Analysis of sensor parameter characteristics and digital control on the electric drive's performance

Current and rotor position sensors are used in field-oriented control of electric drives. The sensors have internal measurement errors, limited bandwidth and signal processing delay times, which influence the control of the drive. The paper analyzes the influence of these parameters on the torque. The sensor influence is investigated for base speed (BS) and field weakening (FW) operation of the drive. An analytical analysis explains the sensor influence on the generated torque in detail and provides an empiric formula for the relationship of a measurement error and generated torque. The conclusions are confirmed by system simulation of the electric drive train in Simulink and measurement results from a test bench.