Approximation of P-V characteristic curves for use in maximum power point tracking algorithms

A curve fitting method that approximates the P-V characteristic curve of a given solar array with a fourth order polynomial is presented. The coefficients of the approximated P-V characteristic curve are strongly dependent on cell temperature. The strong dependence of the P-V curve on cell temperature allows the P-V characteristic curve of a given system to be written as a function of both panel voltage and cell temperature. The curve fitting method presented can be used in an indirect maximum power point tracking algorithm for use with solar powered systems. Experimental results are presented to confirm the validity of the method.