Transient and steady-state performance analysis of hybrid powered DC series motor via DC shunt and PV generators with maximum power point tracking

Abstract

This paper presents a comprehensive transient and steady-state analysis of hybrid powered DC series motor through DC shunt and PV generators. The solar cell generator is interfaced with the system through a DC–DC buck–boost switch mode converter. At full solar irradiance, the PV generator can completely run the DC series motor as its maximum power point is placed at the rated conditions of the DC series motor. As the solar intensity decreases, the shortage of power demanded by the series motor is compensated by the fuel-driven DC generator. To fully utilize the pollution-free PV generator at various solar intensities and, therefore, to reduce the total fuel consumption by the prime mover of the DC shunt generator, the operating point of the solar cells in case of hybridization is adjusted at its maximum power point by automatically calibrating the terminal voltage at the common coupling point of the two generators. The transient analysis comprises step changes in the load coupled to the motor at different solar irradiances and after successive step changes on the solar illuminations for some given fixed loading conditions. The nonlinearities of the PV generator are taken into account along with that of the ferromagnetic material of the two DC machines. The effect of changing the field resistance of the DC generator on the performance of the system is addressed. The steady-state output characteristics of the DC series motor when powered by only PV generator at full solar illumination, in case of hybridization at 0.85 and 0.70 of full solar intensity are outlined and compared.