Maximum power-point tracking of high altitude wind power generating system using optimal vector control technique

In a high altitude wind power (HAWP) generating system, the generation of wind power is carried out at high altitude above the earth surface and control of power generation is accomplished at the ground based station. Three phase medium-voltage permanent magnet synchronous generator (PMSG) is used as the source of power generation in the air-borne unit. The ground based power electronic converters (PECs) are used for maximum power-point tracking (MPPT) of the air-borne wind turbine (AWT). Optimal torque/vector control of the PMSG is best suited for MPPT of HAWP application. The proposed method does not use mechanical sensor in the air-borne system to measure the rotor position. The phase-lock-loop (PLL) is employed to estimate the rotor position, which is used for calculation of MPPT torque/current reference. The AWT is controlled using ground based power conversion system comprising of three-level neutral point clamped (NPC) rectifier for generation side MPPT control. The proposed MPPT control algorithm of the PMSG is validated using MATLAB/Simulink. A 1 kW PMSG generation system prototype is designed in the laboratory and used for experimental validation of the proposed MPPT method.