Variable DC-link Voltage Control Strategy for Starter Motor

Aircraft auxiliary power units demand that starters have the capability for rapid engine cranking and a broad speed range. This paper investigates a low-voltage Permanent Magnet Synchronous Motor/Generator (PMSM/G) for starting, typically utilizing field weakening control or a variable DC-link voltage scheme to overcome excessive back electromotive force (EMF) during high-speed operation. The focus of this paper is on the control process during the motor starting phase, employing an interleaved parallel DC-DC converter in series with a three-phase full-bridge topology to drive the starter motor. By analyzing the operating principles of the circuit, this study proposes suitable variable bus voltage control strategies and compares the advantages and disadvantages of different starting strategies in terms of efficiency losses and starting modes, aiming for a scholarly examination of these techniques.