Voltage regulation and maximum output power tracking of a 4.5kW permanent-magnet synchronous generator

Wind energy is one of the renewable energy been developing in recent years. Wind turbines are generally connected to the utility grid as the generation resources. In local application, the wind generator can be implemented in the DC or AC micro-grid. In the DC micro-grid, the output AC/DC converter of wind generator should accomplish the AC/DC power conversion and maximum power tracking. This paper develops a 4.5 kW permanent-magnet generator drive to convert AC output of wind generator to DC micro-grid. The generator is driven by a permanent-magnet synchronous motor to simulate the wind turbine. The DC-link voltage, line voltages and line currents of the generator are measured to regulate the output voltage and power. The Division-Summation (D-Σ) current control scheme is adopted in this paper. The rotor reference frame transformation is unnecessary in this algorithm, which reduces the execution time of the control unit. Constant output power control, DC-link voltage regulation and maximum power tracking are achieved. The DC-link voltage is regulated by the one line-cycle regulation scheme. The DC-link voltage of the PMSG can be regulated in one electrical period under output power variation. The maximum output power tracking is achieved via perturb and observe method. The current control, voltage regulation and maximum power tracking are verified by experimental results.