MPPT control strategy for off-grid wind power system

Based on analysis of off-grid wind power system characteristics, a maximum power point tracking (MPPT) control strategy is investigated. The new control strategy employs double grey relation analysis (GRA) for maximum power extraction. The first GRA is used the generator output voltage to estimate the maximum power under various wind speed. Then the second GRA is used to estimate the convert duty cycle according to maximum power. The simulations show that in the wind speed changing process the off-grid wind power system can search and trace the maximum power point automatically by using this strategy. Moreover, this control strategy is comparatively easy, and has high practical value.