Coordinated and fault‐tolerant control of tandem 15‐phase induction motors in ship propulsion system

Abstract

Electric propulsion is widely used in ship propulsion systems, and multiphase machines are gaining increasing popularity because of their fault-tolerant ability, high power density, and reduced torque ripple. This study concentrates on the tandem ship propulsion configuration with two 15-phase induction machines (IMs) fixed on the same shaft. Based on fieldoriented control and reconfiguration fault-tolerant control for the single 15-phase IM, the master-slave coordinated control strategy is designed for the tandem motors, which can not only achieve power allocation between two motors during normal operation, but also minimise the total stator copper loss of the two motors and maximise the propulsion output power ability during fault-tolerant operation. Experiment results from a ship propulsion experimental platform verify the effectiveness of the proposed control strategies.

Finite Control Set Model Predictive Control of Six-Phase Asymmetrical Machines—An Overview

“…In opposition to the standard virtual vectors, the dual virtual vectors only contain x-y voltage components, hence the control of the x -y currents can be performed without disturbing the reference tracking of the d-q current components, which regulate the flux and torque of the machine. The dual virtual vectors are created by the combination of a large and a medium-large vector with the same phase in the x-y subspace and the duty cycles given by (32), resulting in twelve dual virtual vectors with an amplitude of 0.598 • U dc in the x-y subspace (stationary reference frame), as shown in Figure 6.…”

“…In addition to the reduced current or voltage ratings per phase, lower torque harmonics, improved fault-tolerant capabilities and additional degrees of freedom, multiphase machines also offer other advantages over their three-phase counterparts, namely: improved winding factors, reduced harmonic content in the magnetomotive force (MMF), lower rotor losses and lesser harmonics in the dc-link current [1,[24][25][26]. Nowadays, electric drives based on multiphase machines are employed in a wide range of areas, such as aircraft [27,28], electric or hybrid vehicles [29], locomotive traction [30], high-speed elevators [31], ship propulsion [32], spacecraft [33] and wind energy applications [34][35][36].…”

Torque Ripple Minimization of a Five-Phase Induction Motor Under Open-Phase Faults Using Symmetrical Components

“…Multiphase motors have been widely used in air-craft drives, locomotive traction, electric ship propulsion and high-power industrial applications [1][2]. As the number of phases increases, the required stator current amplitude can be reduced without changing phase voltages and output power [3][4]. Besides, multiphase motors have competitive advantages over three-phase motors such as lower torque pulsations, higher power density, lower dc-link current harmonics and better power distribution among a higher number of phases [5][6].…”

Reduced-Order Model of Rotor Cage in Multiphase Induction Machines: Application on the Prediction of Torque Pulsations

“…Thanks to the aforementioned advantages, multiphase induction machines are becoming attractive in several sectors especially aeronautics [15], naval [16], and automotive industries [17]. With these increasing demands on multiphase induction machines, the design rules and theories, classically developed for the case of three phases, must be reconsidered.…”