Design and testing of a low cost peak-power tracking controller for a fixed blade 1.2 kVA wind turbine

Wind turbines are a common source of electrical power generation in rural sites around the world. The power generated by a wind turbine at a given wind speed is a non-linear function of rotor speed. This results in a specific rotor speed for maximum power production at each wind speed. A control system incorporating a Pulse Width Modulated DC -DC converter has been designed to vary the load on the wind turbine thereby forcing it to operate at its maximum power point. Another important feature of the controller is the application of electrical stall-breaking of the turbine. The circuit was then tested on a turbine test bed simulating various wind speeds, and the “peak-power tracking” capability and electrical breaking capability were verified. The system gave an overall efficiency of 70 to 80% over a wide range of wind speeds and PWM duty cycles.