A Novel principle of maximum power point tracking for photovoltaic systems

The new principle of power maximizing of solar battery (MPPT) is proposed. The system based on a specific implementation of the PWM DC-DC converters, through which the solar battery is connected to the load. Instead of a linear carrier voltage, typically used in PWM systems, the special created periodic function plays a role of the carrier curve that is mathematically similar to the dependence of the solar panel output power on the duty-cycle of the DC-DC converter connected to it. The function is obtained by scanning a sample low-power solar panel with the special controlled current source. This sample solar panel is located in close proximity to the main battery, and thus its electrical characteristics identical to those of the main one. The maximum of the power curve, obtained in this way at each switching period, determines the value of duty cycle, which should be installed in the main DC-DC converter to achieve MPP. The proposed system is implemented using a simple scheme contained conventional electronic components. The system is characterized by high accuracy and speed. The results of computer modelling and testing of laboratory prototype confirm the theoretical conclusions.