Applied Mechanics and Materials Vols. 668-669

Abstract: In order to obtain the low synchronous speed, fractional-slot concentrated-winding PM machine is adopted to wind power generation system. This paper analyzed the pole slot combination rule, and then studied the electromagnetic design method by taking 12-slot and 10-pole machine. By using the finite element software, the characteristics is analyzed for this fractional-slot concentrated-winding permanent magnet generator, the research results show that this generator has good performance, thus prove that fractional-slot concentrated-winding scheme is feasible and effective.

Abstract: Varying load torque is an important influence factor in speed tracking of PMSM for EVs. This paper presents a PMSM control strategy using load torque observer. After introducing the entire structure of PMSM control system, a state observer is described based on square-root unscented Kalman filtering. Simulation tests are carried out to examine the speed tracking performance of PMSM compensated with the state observer. The results demonstrate that the proposed method is superior to another one using SMC in control accuracy and regulatory time.

Abstract: This paper researches optimization maneuver strategy of UAV after engine stopped to make the loss of height of UAV minimum. Research has been done in two conditions, unpowered balanced glide straight flight and unpowered balanced glide turn maneuver. In this paper, the angle of attack and angle of roll has been given in order to make sure that the loss of the height is a minimum. The results of the simulations show that the optimization maneuver strategy in this paper is correct.

Abstract: In order to analyze the possibility of the fractional-slot concentrated-winding for wind generation, this paper states the merits of fractional-slot concentrated-winding permanent magnet machines, and then analyzes the electromagnetic design rules of fractional-slot concentrated-winding. The fractional-slot concentrated-winding permanent magnet machine is modeled and designed in electromagnetic, and its performance is analyzed, some conclusions can be obtained, which will provide reference for further analysis and application of fractional-slot concentrated-winding PM machine.

Abstract: As the electric vehicles usually run under complex conditions of city road, there always exists parameter perturbation of motor, which will affect the vehicle performance. To solve the problem, an improved sliding mode variable structure control (SMC) method which combines continuous function and reaching law has been proposed in this paper. Then the improved vector control algorithm’s codes are generated automatically in the MMC (Model-based Motor Control) platform. The results show that the improved SMC algorithm has small chattering and strong robustness to the parameter perturbation and the external disturbances.

Abstract: Variable cycle engine is a complex system, which is usually mathematically modeled as a series of multi-dimensional nonlinear implicit equations. Processes for solution of these equations are often complicated; therefore, a genetic algorithm-based method was presented in this paper for the solution of the mathematical model. The method was also evaluated by such parameters as initial value sensitivity, computation efficiency, convergence and stability; and compared with Newton-Raphson method. It shows that genetic algorithm-based method is less sensitive to initial values, more capable in convergent and computing stability than Newton-Raphson method, however more time consuming.

Abstract: In the foundation of the realization of sensorless control of permanent magnet synchronous motor(PMSM) based on the traditional sliding mode observer, the paper focuses on the research on the chattering impacts on the estimation of rotor position and speed, which are caused by the sliding mode variable structure control. To weaken the chattering, the paper proposes two kinds of methods. First, the paper designs the saturation function with boundary layer thickness variable instead of sign function in the traditional sliding mode observer. Meanwhile, let the phase-locked loop (PLL) combine to the sliding mode observer, and construct the rotor position signal detection unit. Finally, the paper verifies the correctness and effectiveness of the proposed methods through the theoretical analysis and simulation.

Abstract: Electric vehicle (EV) is one of the current research focuses due to its environmental friendliness, but the inaccuracy in remaining driving range (RDR) estimation lowers the consumers’ confidence on EVs. This paper introduces a remaining driving range estimation method based on information fusion (RDRIF), in which the RDR is determined by the fusion of the calculated range (calculation of the present battery and vehicle consumption states) and the cumulated range (cumulation of the real-traveled distance) to provide a accuracy RDR result. The RDRIF algorithm was embedded in a type of pure electric vehicle, and a set of vehicle experiments was carried out on a dynamometer test system. Two urban driving cycles representing normal and aggressive driving conditions are implemented in the tests to validate the effectiveness of RDRIF. The results show that the RDRIF could provide a stable and convergent estimation result under both driving conditions compared with the traditional methods, and the estimation error could be rapidly limited to ±5%, which effectively reduces the passengers’ range anxiety.

Abstract: A model of directed transport of elastically coupled Brownian motors in a two-dimensional potential is established, in which one AC drive and a noise are acted on the non-ratchet potential direction but none is acted on the ratchet potential direction. Through numerical simulation, the position and the velocity of the coupled Brownian motors in two directions versus time are analyzed in different cases, which include that the AC drive and the noise are all moderate in the non-ratchet potential direction, no AC drive or no noise. The results show that at appropriate AC drive or the noise, there is a directional flow in the ratchet potential direction none acted.

Abstract: The influence of impulse corona is taken into consideration by inserting equivalent complementary capacitance at both terminals of each short line based on its analysis. The model of tower is improved so that we can consider the effect of coupling ground wire (CGW) as well as that of impulse corona. The contrasts of lightning back striking simulation results show that impulse corona and CGW affects the breakdown data of transmission line and insulators greatly.