An Improved Hill-climbing Searching Method Based on Halt Mechanism

To avoid oscillations of rotor speed at maximum power points(MPP) and to overcome wrong searching directions for MPPs due to the turbulence of wind speed,an improved hill-climbing searching(HCS) method for maximum power point tracking(MPPT) was proposed.It not only inherits the advantage of the variable-step HCS method so that MPP can be rapidly reached,but also introduces the mechanisms of detection and halt at MPP.Thus,the mechanical damage to wind turbines around MPP,resulted from rotor speed oscillations can be effectively reduced.Moreover,following the halt of HCS,the disturbance to determinations of searching directions caused by wind speed variations was resolved and as a result more wind energy was captured.Based on a simplified model of the wind energy conversion system,simulation studies were presented to verify the effectiveness and advantage of the improved method.