This paper presents a review of the electrical and electronic technologies investigated in more-electric aircraft (MEA). In order to change the current situation of low power efficiency, serious pollution, and high operating cost in conventional aircraft, the concept of MEA is proposed. By converting some hydraulic, mechanical, and pneumatic power sources into electrical ones, the overall power efficiency is greatly increased, and more flexible power regulation is achieved. The main components in an MEA power system are electrical machines and power electronics devices. The design and control methods for electrical machines, and various topologies and control strategies for power electronic converters have been widely researched. Besides, several studies are carried out regarding energy management strategies that intend to optimize the operation of MEA power distribution systems. Furthermore, it is necessary to investigate the system stability and reliability issues in an MEA, since they are directly related to the safety of passengers. In terms of machine technologies, power electronics techniques, energy management strategies, and the system stability and reliability, a review is carried out for the contributions in the literature to MEA.

This paper proposes a modular seven-leg switched reluctance motor (SRM) drive with flexible winding configuration and fault-tolerant capability. In traditional SRM drives, the winding connection is fixed, where the speed regulation range and fault-tolerant ability are both limited. To solve these issues, a modular seven-leg drive topology is proposed, where each phase winding is divided into two segments, and the winding connection can be flexibly switched to achieve a wide speed range. At low speed, the winding segments are connected in series for a higher output torque, while the parallel connection is employed at high speed to extend the speed range. In addition, a swift and smooth online winding switching process is achieved, where there are no current or speed shocks. Furthermore, owing to the flexible winding connection in the proposed topology, effective fault-tolerant strategies are developed to deal with the open-circuit faults in both series and parallel connections, which can maintain the output capability and avoid large torque ripples when open-circuit faults occur. Meanwhile, the proposed drive topology is constructed by commercial half-bridge modules and is suitable for industrial applications. Simulations and experiments are carried out on a three-phase SRM prototype to verify the feasibility of the proposed scheme.

When an emergency happens to electric vehicles, the voltage of the DC-bus capacitor which is an important part of the permanent magnet synchronous machine (PMSM) drive system requires to be reduced as quickly as possible. Recently, a new idea of directly using the windings to discharge the capacitor has come forth. This paper proposes a physical energy flow model (EFM) to explain explicitly the winding-based discharge mechanism firstly. In the EFM, the performance characteristics of a classical winding-based discharge schemes are evaluated, but it is found that the discharge time will not be qualified when the machine rotor inertia is large and the system safe current is small. To reject intense voltage surge, a current control algorithm is proposed to bleed the capacitor voltage. Moreover, the proposed current control method shortens the discharge period within 3s for the system studied. The proposed discharge algorithm has been verified in experiment.

In order to enhance the dynamic performance of the surface-mounted permanent magnet synchronous machines (PMSM), this paper proposes a novel finite control set (FCS) model predictive direct speed control (MPDSC) strategy that only contains one speed control loop. In comparison with the traditional two-step prediction method, the new controller is achieved by estimating the current at first and then the speed with only one prediction horizon. The practical problem that the optimal switching state cannot be selected by the common implementation procedures of the FCS model predictive control algorithms can be solved by applying the proposed strategy that conforms more to the real situations. Moreover, in order to solve the other critical problem that the load torque (LT) in the predicting plant is unknown, a novel sliding mode LT observer is developed. The simulation and experimental results prove that the proposed algorithms are effective.

For the open winding permanent magnet synchronous motor (OW-PMSM) with leg open-circuit faults, a novel zero-sequence current (ZSC) suppression method with asymmetric zero-sequence voltage (ZSV) injection is proposed in this article. To realize the fault-tolerant control (FTC) in leg open-circuit fault conditions, the leg-sharing method is developed, where the output terminal of the faulty leg is connected to that of the remaining equivalent leg. However, the ZSC increases in the FTC mode, which causes severe torque ripple and system performance degradation. If the traditional ZSC suppression method is still adopted, the suppression performance is decreased. Besides, an undesired voltage vector is introduced, resulting in current distortion. To solve these problems, a novel ZSC suppression strategy is put forward. By asymmetrically adjusting the voltage output of the remaining legs, the ZSC of OW-PMSM in FTC mode can be effectively suppressed. Moreover, the proposed strategy is suitable for both the single-leg and double-leg FTC modes, where the ZSC suppression performance is almost the same as that of the traditional method in normal operation mode. Furthermore, experiments are performed on an OW-PMSM to verify the effectiveness of the proposed ZSC suppression scheme.