Applied Mechanics and Materials Vol. 344

Abstract: The brushless doubly-fed machine (BDFM) is a new type of induction machine which has different structure and operation principle than a conventional AC machine. In this paper, the electromagnetic relation of BDFM is analyzed, and a stand-alone generator system is presented. Based on the analysis, the characteristic and applicability of scale and vector control strategy is build, both of which realize constant voltage output in stand-alone generator systems of variations load.

Abstract: Cascaded multilevel inverters could realize high-voltage output based on a series connection of power cells which use standard low-voltage component configurations. This characteristic could achieve high-quality output voltage waveforms and input current waveforms. These merits are made for motor control, especially in the field of speed-sensorless vector control of induction motor based on the theory of MRAS. This paper constructs a simulation system with the help of MATLB/SIMULINK and a system combined cascaded H-bridge multilevel inverter with induction motor with the help of DSP and FPGA. The simulation and experiment results verified the superiority of cascaded multilevel inverter applied on the MRAS speed-sensorless vector control of induction motor.

Abstract: The control problem of certain type of aero-engine is studied in the article. And active disturbance rejection control (ADRC) is applied into the control of aero-engine. In light of the problem of parameter optimization in ADRC, through the principle of parameter optimization analysis, rule of parameter optimization is revealed in this article. Based on parameter optimization rule, an adaptive parameter optimization law is designed to optimize the parameter of ADRC by on-line adaptive parameter tuning method. Some conclusions are suggested by the simulation result: compared with PID controller, that the ADRC controller is proved better in responding time, overshoot, steady-state error, disturbance rejection performance and control performance.

Abstract: Light-emitting diodes with optoelectronic feedback loop display complex sequences of periodic mixed mode oscillations and chaotic spiking. In this paper, we propose an adaptive neural control scheme for chaos synchronization of two unidirectional coupled LED systems. Based on Lyapunov stability theory, the controller can stabilize the synchronization error dynamics at the origin point, thus chaos synchronization can be obtained. The simulation results demonstrate the effectiveness of the proposed control scheme.

Abstract: The design of the wheel-legged mobile robot is mainly used for the early toxic gas leakage warning and disaster relief in the field of wild environment. The robot needs to cross some obstacles such as ditch and step when carrying out a task. The paper analyzes the strategies of robot passing the all kinds of obstacles. Considering the influence of disturbance by uneven road surface, the dynamic model of robot crossing the step and groove on the uneven road surface is built based on the robots structural features. While the control model of front wheel-leg is also presented based on the robot dynamic model. The results of simulation expriments demonstrate the correctness of the built dynamic model and laid the foundation for the design of the robot control system.

Abstract: This paper proposed a kind of intelligent driving module based on the requirements of high pressure common rail fuel injection system. Many functions of this module were designed such as current multiply holding , boosting and energy recovering. This module occupies less microcontroller resources and makes injectors solenoid valve pull more smoothly. The experimental results show that the solenoid valves peak current can achieve to 20A within 0.1 ms and the storage capacitys potential was not changed significantly. This intelligent driving module could achieve the requirements of high pressure common rail driving circuit.

Abstract: In this study, a light tracked vehicle powertrain plant as a research platform, do simulation and experimental studies for upshift dynamic process of the tracked vehicle, study the effect that using active control strategy for the integration of the tracked vehicle impact on ride comfort and acceleration. The results show that in the upshifting process, active reduction of engine oil control can improve vehicle ride comfort, but the increase by reducing fuel consumption and reduce the reducing time will lead to increase shift smoothness and increase upshift power loss.

Abstract: The traditional control technology of doubly fed wind power generator is based on stator flux-oriented control technology but not considering the volatility of wind speed, the non-linear and the robust control of wind generator. This article gives a coordination control technology of DFIG-SMES (Superconducting Magnetic Energy Storage) based on Hamilton function. It derives the stability region of controller parameters and proves the stability condition. It designs and builds control test system of DFIG-SMES controller based on MSP430 chip. It achieves good results through experiments under random wind. The study establishes the foundation for the hardware platform of nonlinear and robust control system of DFIG.

Abstract: A period-doubling bifurcation may occur when the estimation error of the rotor time constant exists in an indirect field-oriented control (IFOC) of induction motor drives. Then chaos oscillations appear under some parameter values which are usually tested by the Largest Lyapunov exponents. In this paper, we apply the modified 0-1 method to detect chaos phenomenon instead, and design a controller to suppress chaos in the IFOC system. Simulation results indicate that the proper parameter region of the controller can be obtained with this method, and with the adaptive controller the system can quit from the chaotic state into the stable state effectively and robustly. The 0-1 method identifies chaotic behaviors directly through the time series without constructing phase space. Therefore, the proposed method is not affected by the complexity of the system and is not sensitive to noises.

Abstract: In this paper, a novel variable speed constant frequency brushless doubly-fed induction generator system using back-to-back multilevel converters for high power stand-alone power generation is described. According to control target, the unified reference-frame model is used to develop an improved forced power stator flux oriented vector control strategy. The similarities and differences between the grid-connected and stand-alone topology and control strategy are also specialty analyzed and compared. Simulation results prove the feasibility and validity of the proposed model, theoretical analysis and excellent performance of the proposed control scheme.