Analysis of a dual-winding fault-tolerant permanent magnet machine drive for aerospace applications

With the increasing development of aircraft and helicopter, new electric drive system for aerospace applications have attracted more and more attentions in the aviation sector [1]-[2]. The common hydraulic drive helicopter winch is replaced by the electric drive helicopter winch gradually, due to the fact that the electric drive system can not only improve the system efficiency and the flexibility of variable speed control, but also reduce the weight and volume of the system [2]-[3]. However, in the electric drive helicopter winch systems, where continuous operation must be ensured, high reliability and strong fault tolerance become a critical requirement [2]-[4]. The purpose of this paper is to propose a new electric drive helicopter winch system based on a six-phase ten-pole dual-winding fault-tolerant permanent magnet (DFPM) machine. The DFPM machine, which incorporates the merits of high power density and high efficiency of permanent magnet (PM) machine and high fault-tolerance of dual-winding machine, consists of optimal surface-mounted permanent magnet rotor and 12 slots stator with two sets of independent three-phase concentrated armature windings on alternate teeth. To achieve the fault-tolerant performance, the redundant fault-tolerant control strategy based on speed, current, voltage three-loop control is proposed and analyzed. Then, the electromagnetic performances of the DFPM machine drive with an open-circuit fault under load hoisting and dropping conditions have been verified by experiments. The research results showing the effectiveness of the proposed fault-tolerant control strategy and the high performance of the fault-tolerant characteristic of the proposed DFPM machine drive.