Enhancement of DC voltage regulations in micro grid by using super capacitor and series compensator

Abstract In situations where renewable energy sources like the solar photo voltaic sources are used the voltage level of the delivered DC output of the power converter interfaced to the primary energy conversion system may exhibit marginal changes in terminal voltage caused by climatic conditions or other natural disturbances. This article investigates how a super capacitor (SC) along with a synchronous buck boost converter (SBBC) may be used to address the short term voltage falls or overshoots arising out of climatic conditions like passing clouds or interruption by birds and so on. The work demonstrates how a series compensated buck boost converter (SCBBC) may be used to harvest solar PV power. The transfer function of the SCBBC has also been developed using the energy function technique. Further, this work also demonstrates, in an AC fed system, how the source and the load side disturbances may be addressed effectively in a diode bridge rectifier using the proposed super capacitor based active compensation system. Further, the influence of sudden fall of solar irradiance, in the speed of a solar PV powered permanent magnet DC motor (PMDC) has also been studied and the applicability of the proposed SC based compensation scheme for smoothening the speed of the PMDC motor has been demonstrated. The proposed idea has been validated using simulations in MATLAB SIMULINK and experimental prototypes.