In this paper, an improved two diode model of photovoltaic module is simulated using MATLAB/ Simulink. Only four parameters(Voc, Isc, Vm, Im) are required to simulate the model. Accuracy of the model is validated by testing various modules of different types (Multi Crystalline, Mono Crystalline and Thin Film). The proposed model is found to be accurate when subjected to variation in temperature and solar irradiance. The values of various important parameters ie Voc, Isc, Vm and Im obtained from current-voltage and power-voltage curves of the proposed model are almost similar as the values supplied by the manufacturer.