Researchonhigh Efficiency Low-power Wind Power Generation And Grid System

Energy crisis makes renewable energy develop rapidly. As a clean and pollution-free energy, wind energy has been draw attention by all countries. Small grid-connected wind power expands the availability of wind resources and reduces the cost of system where there are low-voltage and low wind speed.At present, low-power grid-connected wind power system still has many problems: converter works at hard-switching state. The switching loss is large which limited the system efficiency. When the wind speed changes rapidly, the traditional max power tracking control algorithms can't track fast and the tracking efficiency is reduced. The dynamic response and grid-quality of grid-converter is slow. In this paper, low-power grid-connected system is studied and the traditional grid converters are analyzed. For the traditional converters operate in hard-switching state with large switching loss, new Boost soft-switching converter is used, which is used as the main circuit of MPPT controller, the loss is reduced and the efficiency is improved. Considering the rapidity and stability of tracking process, an adaptive cycle duty algorithm is designed, the tracking step changes with the wind speed in real time, achieving good performance when the wind speed changes faster or slower and the tracking speed and steady-state response are improved. With the two methods, the efficiency of system is improved. Comparing the advantages and disadvantages of traditional grid control strategy, double closed loop control strategy is designed. Outer loop control DC bus voltage and inner loop tracks the current with optimized sliding mode control. The dynamic response and grid quality are improved.At last, software and hardware are designed by TMS320F2812. Simulations and part of experiments are given and the simulation and experimental results are given.