Advanced Materials Research Vols. 383-390

Abstract: As a new paradigm of Swarm Intelligence which is inspired by concepts from ’Social Psychology’ and ’Artificial Life’, the Particle Swarm Optimization (PSO), it is widely applied to various kinds of optimization problems especially of nonlinear, non-differentiable or non-convex types. In this paper, a modified guaranteed converged particle swarm algorithm (MGCPSO) is proposed in this paper, which is inspired by guaranteed converged particle swarm algorithm (GCPSO) proposed by von den Bergh. The section sizing optimization problem of steel framed structure subjected to various constraints based on Chinese Design Code are selected to illustrate the performance of the presented optimization algorithm.

Abstract: The paper presents the inverter method which based on cascade multilevel inverter and MOSFET-assisted soft-switching of IGBT and modulation strategy against the double requirement of high-power inverter and high frequency. The method can effectively improve the output voltage, reduce harmonic distortion and switching losses, improve the switching frequency and meet the double requirement of the high-power inverter and high frequency. The method proved to be feasible by simulation and experiment.

Abstract: A synchronous permanent magnet planar motor (SPMPM) with Halbach array is proposed. The flux density distribution of Halbach array is obtained by analytical method; then, the characteristics of SPMPM with Halbach magnet array are evaluated. At last, the experiment results are used to verify the analysis propriety of this SPMPM. By comparison, it can be concluded that the analysis of SPMPM with Halbach magnet array is credible and feasible.

Abstract: The stability control domain of beam’s non-linear vibration with time-delay feedback controller was investigated. The non-linear dynamic equation of beam was expanded into a series of linear equations by multi-scales method. The equations of the phase trajectory could be gotten from secular terms. The conditions of the negative real roots could be calculated by the method of Routh-Hurwitz. The stable time-delay domain of beam’s non-linear vibration was given.

Abstract: Pulse detonation engine is a kind of new engine for spacecraft, it is difficult to control for there is no moving parts in engine combustion chamber and detonation speed is very fast. The engine model was given based on thermodynamics equations in the paper. A multi-rate digital controller for a pulse detonation engine based on the engine model was also given. The simulation results show that the control method is effective. The detonation engine model provides a basis for developing and validating controllers capable of controlling the engine.

Abstract: The paper presents the making of driver-motor-reducer and turntable system, and builds a mathematical model of this system. The design of a self-tuning PID controller and the simulation of the whole system are realized by using the MATLAB fuzzy logic tool. The simulation results show that the turntable servo system with the fuzzy self-tuning PID controller has a slight overshoot, fast response, good accuracy and robustness etc.

Abstract: Fire detection based on sequences of images is more suitable for the need in big room or badly environment. Color and contour are both the important features of a flame image. The method to extract the contour feature of a flame image is developed based on threshold of flame area. The edges of the burning flames jitter continuously, but their contour are similar each other. The method to detect flames in video sequences is proposed here based on flame’s dynamic contour. Many experiments show that the system is able to work well and get high detection rate with a low false positive rate.

Abstract: In Photovoltaic (PV) system, the output characteristic of PV cell is susceptible to external environment, such as temperature, light radiation etc, and showing obvious nonlinear. Therefore, in order to improve the efficiency of PV system, the maximum power point tracking (MPPT) of PV cell is essential. This paper mainly introduces the simulation of PV cell and the methods commonly used in Maximum Power Point Tracking of PV system. For the perturbation and observation (P&O) method the paper presents a new variable step size algorithm and builds a simulation model. The result shows that the proposed algorithm has a better effect on maximum power point tracking of PV cell.

Abstract: A flux-switching electrical machine (FSEM) has similar structure to a flux-switching permanent magnet (FSPM) machine. It takes on excellent sinusoidal flux linkage and back EMF when the field and armature windings are well placed so that it can be a good candidate as an AC generator. This paper brings up to five topologies of a 12/10 FSEM, does researches on their basic characteristics and makes comparisons between them. The results are validated by simulations.

Abstract: This paper proposes a unified method for inter-area power oscillations which is the key to solve coordination problems caused by different mathematical models and control theories. Firstly, the unified model, breaking the constraints of the network topology, component and the precise extents in the process, is established based on global signals. Secondly, making use of the structural feature of the unified system model, it combines advanced control theory to resolve the problem of parameter uncertainty and model error. Finally, the control law is effectively derived with backstepping method. The simulation results in Matlab show the validity of the proposed method.