Hardware implementation of DC-DC converter for MPPT in PV applications

Photovoltaic Cell (PV) is an environment friendly source for electric power generation. This is relatively costly as compared to the other available sources of energy. The maximum power point tracking (MPPT) for the PV system application provides PV generated power for all irradiation conditions to have the maximum output power. It results in low per unit cost of power for efficient PV system. MPPT is important unit in photovoltaic power systems because it increases the system efficiency by increasing the output power. Normally, PV panel generates nonlinear Voltage-Current characteristics and its unique point varies with solar irradiation where the maximum power is produced. To extract maximum power from the solar panel, it needs to operate the photovoltaic (PV) system at the maximum power point (MPP) or unique point. MPPT consists of DC-DC Converter and MPPT algorithm. This paper presents a Hardware implementation of DC-DC push pull converter based on TL598 control circuit to track maximum power point. TL598 is a fixed frequency and variable duty cycle control IC for charge controller purpose. However, here we have used this converter for different purpose to maintain MPP PV voltage. We have achieved this with the help of MPPT algorithm by simply applying adjustable external voltage at Pin 4 of Dead Time Control (DTCON) of IC TL598. The adjustment of voltage depends on the algorithm. This can improve the tracking speed and stability of output power at unique point. This is suitable for various maximum power point tracker algorithms. The resultant DC-DC converter extracts power directly from MPP algorithm and is capable of tracking MPPs accurately, rapidly.