Hybrid renewable energy system utilizes two or more production methods, usually solar and wind power. A Charge Controller is a device that controls the flow of current to and from the battery subsystem to protect the batteries from overcharge and over discharge. There are different types of charge controllers such as Analog series/shunt mode charge controller, ON/ OFF charge controller, Pulse Width Modulation technique based charge controller are having efficiencies of 60% to 70%,65% to 75% and 75% to 85% respectively. The MPPT types are newly introduced and are latest trend in market. They are more costly and better suited to large systems. The MPPT charge controllers charges the battery at full power by maintaining efficiency of 90% to 93%. Among all discussed charge controllers, the MPPTs provide excellent efficiency however they are costly. The main disadvantage of existing type of circuitry is that their efficiency is very low as the circuits do not consider input power and output power. Thus any mismatch between input and output power may lead to loss of power resulting in lower efficiency. The status of charged battery can be known only from LED displays. Thus the actual battery voltage cannot be known. The system cannot be used for large current applications. Actual battery voltage cannot be monitored. The analog ICs have been implemented which are not intelligent devices. To overcome disadvantages of above said analog system the proposed system is developed. This system will use microcontroller which is an intelligent device, it will switch ON and OFF the MOSFET according to status of battery (whether fully charged or discharged). In addition it will also display the present voltage on battery indicating actual status of battery.
Kale, Geeta Laxmanrao and Shinde, N.N.
"Implementation Of Prototype Device – Off Grid - Charge Controller – Suitable For Wind Solar Hybrid System,"
International Journal of Mechanical and Industrial Engineering: Vol. 1
, Article 4.
Available at: https://www.interscience.in/ijmie/vol1/iss1/4