Distributed speed control for multi-three phase electrical motors with improved power sharing capability

Abstract

Abstract-This paper proposes a distributed speed control with improved power sharing capability for multi-three phase synchronous machines. This control technique allows the speed to be precisely regulated during power sharing transients among different drives. The proposed regulator is able to control the time constant of the current within the dq0 reference frame to a step input variation. If compared to current set-point step variations, the proposed droop controller minimises device's stress, torque ripple, and thus mechanical vibrations. Furthermore, since distributed, it shows improved fault tolerance and reliability. The design procedure and the power sharing dynamic have been presented and analysed by means of Matlab/Simulink and validated in a 22kW experimental rig, showing good agreement with the expected performances.

Response to Discussion of “A Modular Speed-Drooped System for High Reliability Integrated Modular Motor Drives”

“…The overall control strategy and the design procedure of each loopcurrent, sharing, and speed -is presented and validated by means of experimental results. Two off-the-shelf three-phase induction machines coupled on the same shaft and controlled by a custom inverter were loaded by a third off-the-shelf threephase induction machine.A similar control strategy has been validated by the same main author on a multi-three-phase two pole wound field synchronous generator with nine phases [3]. The difference is in the nature of both the electro-magnetic and mechanical couplings.…”

“…The difference is in the nature of both the electro-magnetic and mechanical couplings. Indeed, whilst in [1] there is no electro-magnetic coupling between the stators of the two induction motors and the mechanical coupling is elastic, in [3] is the opposite. Mutual electro-magnetic interactions among different sets of windings within the stator are present and, since there is only one rotor, the mechanical coupling is rigid.…”

“…The same as in [1], the speed loops in [3] were coded on a single control platform for simplicity. In [1], a custom control platform developed by the PEMC (Power Electronics Machine and Control) group at The University of Nottingham, UKpresented in [4], Fig.…”

“…3 -was used. In [3], a newer custom control platform name uCube [5] and developed by the same group was used.…”

Active and Reactive Power Sharing Between Three-Phase Winding Sets of a Multiphase Induction Machine

“…The concept was successfully applied to permanent magnet (PM) machines, with the validity demonstrated on a six-phase [5] and a nine-phase machine [6], [7]. The approach was further found to be very useful in devising regenerative testing methods for machines with multiple three-phase windings, as detailed for twelve-and six-phase PM machines in [8], [9] and [10], respectively.…”