Control of Wind Turbine‘s Load in order to maximize the Energy Output

Abstract

Small-scale wind-based water heating system is proposed and researched. System has a small wind turbine with permanent magnet synchronous generator loaded by the heating element, which is placed in the heat storage tank. The pulse-width modulator is used for the load control. The suggested scheme allows supplying the surplus of electric power from the WT into electric grid in cases when the heat storage tank is fully charged. Control of the water heating process and the power supplying into electric grid process in the researched scheme is realised by using the load control unit, two-step controller and the pulse-width modulator. Mathematic model for the presented water heating system was worked out and researched. Research of the mathematical model disclosed that using of the pulse-width modulator allows controlling the water heating process and the power supplying into electric grid rather efficiently. The possibility to maximize the wind turbines power by adjusting the load to every value of the wind velocity was checked. Results of the simulation also allowed estimating that the form of the inverted current is not sinusoidal. Therefore the filters for the inverted current must be installed on output of the inverter. Ill. 7, bibl. 10 (in English, summaries in English, Russian and Lithuanian).