International Journal of Scientific and Research Publications, Volume 4, Issue 5, May 2014 2
ISSN 2250-3153
The charge controller for wind energy source is operated as: blocking reverse current, preventing overcharge, control
set points vs. temperature and control set points vs. battery type. In wind generator, the reverse current is controlled by using one kind of semiconductor diode. The diode used for blocking reverse current is called a “blocking diode”.
The overcharging of the battery can be prevented by using pulse width modulation (PWM) controller. The ideal set points for charge controllers depend on the types of the batteries. Some controllers have a means to select the type of battery.
II. PROPOSED CHARGE CONTROLLER
The charge controller intended to design and implement in this research work is a small power charge controller. Figure 2.6 shows the block diagram of the charge controller. The charge controller is built around semiconductor switches (silicon controlled rectifier -SCR) rather the electromechanical switches (relays). The microcontroller is used to control
the overcharging of the battery, to display the battery voltage continuously and to make audible alarm when the battery
is fully charged. Firstly the battery is charged using high current through the SCR. When the battery almost reaches its full terminal voltage (full charge) high current charging is cut off and slow charging (trickle charging) is still done. At full charge condition the charging is totally cut out by the control of the microcontroller. The current coming from the wind turbine through the converter circuit is diverting to another load (e.g. lamp). By this means the overcharging of the battery is prevented. The constructed charge controller can charge the 12 V battery with up to 6 A of current. The amount of charging current can be increased by changing some components in the charge controller without any difficulty.