This paper presents a novel intelligent fault-tolerant control method for a kind of more electric aircraft AC/DC hybrid electrical power system, in order to ensure the safe operation of the engine and improve the power supply quality. The more electric aircraft electrical power system was combined with an aircraft engine, two generators, two AC/DC rectifiers, two DC/AC inverters, DC loads, and AC loads. A multi-objective optimization intelligent sliding mode fault-tolerant controller was obtained for aircraft engine with actuator faults. Each of AC/DC rectifiers is 12-pulse autotransformer rectifier unit with active power filter. Active power filter was used to realize the desired performance of DC bus. Intelligent fractional order PI controller is presented for AC/DC rectifier by considering multiple performance indexes. In order to guarantee the AC-side has satisfying voltage, current, and frequency, no matter the sudden change of AC load that happens or DC/AC fault that occurs, the virtual synchronous generator control method was used for DC/AC inverters. Simulation results verify the effective of the proposed more electric aircraft AC/DC hybrid electrical power system.

This paper is devoted to modeling and numerical simulation of electromechanical transients in a passive suspension single degree of freedom system with eddy current dampers (ECD). The damper consists from an inductor with permanent magnets and a nonmagnetic conductive hollow cylindrical rotor. A mechanical actuator is used to convert a translating motion into rotation of the rotor. A full dynamic mathematical model of the ECD and the suspension system is presented. The model takes into consideration electromagnetic transients and nonlinear characteristics of the ECD. The analysis of dynamic behavior of the system is performed by computer numerical simulation. The simulation results show that the mutual influence of electromagnetic and mechanical processes should be taken into account for increasing the accuracy, up to 20% in some cases.

This paper investigates an electromagnetic worm-like locomotion system (WLLS) with simple design and control. The WLLS consists of two elastically connected ring-like segments that form two coupled electromagnetic actuators. The actuators generate longitudinal and transverse displacements that lead to locomotion due to changes of normal pressure and friction forces. The paper presents the electromagnetic WLLS design and the locomotion principle. A simplified approach to the analysis, modelling and simulation of the vibration-driven locomotion has been developed. The numerical simulation results show that the electromagnetic WLLS is able to move and climb quite quickly in inclined pipes. The obtained model allows to determine optimal controls and parameters, for example, to achieve high traction ability of the WLLS.

An electromagnetic 2D model of axial-flux eddy current brakes with slotted conducting disk rotor is proposed. The 2D model takes into account variations in magnetic field strength and eddy current densities in radial and tangential directions. However, the proposed model neglects nonuniformity of primary field created by an inductor because this can be evaluated from separate consideration of the primary field and corrected by a coefficient that enhance well-known Carter coefficient. The using of dimensionless variables gives a main parameter - dimensionless frequency that characterize intensity of electromagnetic process and match with Laithwaite goodness factor and the Reynolds number for MHD machines. For the plain disk rotor without slots, the 2D model was simplified a 1D model that was solved by an analytical method. The 2D model was solved by the numerical finite-difference method. Finally, the torque-speed characteristics was obtained and they show that the torque of the brakes with slotted disk rotor is more the torque of the brake with plain rotor in 1.1-1.2 times; the slope of the torque-speed characteristic increases on 3-10 %.

Partial discharge (PD) measurements have long been used in laboratory to evaluate insulation condition and as a quality control test for manufactured equipment. However, at recent decade, PD measurement has been widely applied to diagnose different equipment units at operating voltage. Now, data showing dependences of various PD parameters from the insulation aging degree are insufficient. The growth changes of PD power at different stages of insulation aging are investigated in this article. Different parameters of partial discharges during a long time of insulation aging were measured. The influences of the basic PD parameters depending on the insulation aging degree are investigated. It is shown that one of the most effective diagnostic parameter is the growth rate of PD power.

Electromechanical pumps can be used in robotics, automation, and transportation. Nowadays, it is urgent to develop methods for controlling the electric drive of pumps to ensure high efficiency and operation in a wide flow range. For example, the regulation of an aviation fuel pump is very important to increase the efficiency of more electric engines. Therefore, a double closed-loop predictive control method with fast vector selection of aviation electric pumps was proposed and analyzed. To increase the electric motor control performance, a novel vector selection method based on geometric principle was developed. Considering the discrete characteristics of the inverter, finite set predictive control theory was used for the motor control. To obtain the appropriate first and second voltage vectors and corresponding function time, the best basic voltage vectors were determined by the reference voltage vector regions based on the geometry principle of triangle similarity and balanced equivalent theory, and thus the control of motor rotor speed and average flow rate of the pump can be realized quickly and accurately. Simulation results showed that compared with cascade PI control, the average flow rate of the aviation pump based on the proposed method has better performance without overshoot. Besides, the d-axis current fluctuation amplitude is remarkably reduced, and the control accuracy was significantly improved. Therefore, the developed method is promised for the flow regulation of aviation pumps and the vector control of motors.