Control and Energy Monitoring Scheme for a Stand-Alone Wind Energy Conversion System

Present energy need heavily relies on the conventional sources. But the limited availability and steady increase in the price of conventional sources has shifted the focus toward renewable sources of energy. Among the available alternative sources of energy, wind energy is considered to be one of the proven technologies. With a competitive cost for electricity generation, wind energy conversion system (WECS) is nowadays deployed for meeting both grid-connected and stand-alone load demands. However, wind flow by nature is intermittent. In order to ensure continuous power supply, suitable storage technology is used as backup. A storage system such as a battery bank may be used. In this thesis, the sustainability of a hybrid wind energy and battery system is investigated for meeting the requirements of a stand-alone dc load. A charge controller for battery bank based on turbine maximum power point tracking and battery state of charge is developed to ensure controlled charging and discharging of battery. The mechanical safety of the wind energy conversion system is assured by means of pitch control technique. Both the control schemes are integrated and the efficiency is validated by testing it with various load and wind profiles in numerical computation software SCILAB. The SCILAB model is intended to simulate the behavior of wind turbine using synchronous generators and control the wind electrical energy conversion processes. Rotational speed and torque become the controlled variables in wind energy and mechanical energy conversion process. Control scheme has been developed for switching DC-DC buck type converter. It is possible to predict the behaviour of the system by simulation using SCILAB-XCOS software.