Passive automatic maximum wind energy tracking wind power generation system
This paper proposes a novel off-grid wind power generation system, comprising a double-winding permanent magnet synchronous generator, a three-phase controllable saturated reactor, two rectifiers, a battery and a load. The output power curve of the new system keeps in accordance with the maximum output power curve of the wind turbine, which makes the system track maximum wind energy automatically. A 300W prototype was manufactured. Experimental results show that the power output curve of the new system matches with the maximum output power curve of the wind turbine in a wide range of rotational speed. Compared with the traditional system, Wind energy utilization coefficient of the new system is improved greatly.
Average modeling of three-phase and nine-phase diode rectifiers with improved AC current and DC voltage dynamics
This paper presents a new average modeling approach for three-phase and nine-phase diode rectifiers with improved AC and DC dynamics. The key assumption taken in this paper is to model the DC load current using its first-order Taylor series expansion throughout the entire averaging timespan, i.e., commutation and conduction periods. The resultant average models present an excellent steady-state and transient behavior, matching their respective detailed switching models with less than 1 % measured error. Moreover, the analytic nature of these models makes them suitable for simulation and stability studies of variable frequency power systems. The paper presents an in-depth description of the modeling approach, together with a thorough static and transient validation of the proposed models. The model is validated through comparison of average model in MATLAB, switching model in Saber and the experimental results
CMEOC—An expert system in the coal mining industry
Abstract This paper introduces an expert system in the mining industry, called the Coal Mining Expert and Optimization Consultation System (CMEOC). The paper mainly describes the architecture of this system, including the knowledge base, inference engine, and relevant optimization techniques. The techniques include multi-objective programming, fuzzy sets, and integer programming. The application results present evidence of the usefulness of the system.