Decoupled Power Control Of Variable Speed Pumped Storage Systems

Today, Variable Speed Pumped Storage (VSPS) system is an important technique that is being used in hydro powered projects to increase the efficiency, quality and control of power being produced. The VSPS systems based on Doubly Fed Induction Machine (DFIM) are emerging due to the cheap cost of the power electronics back-back convert-ers i.e. the converter handles only the 30% of the total power of the DFIM. There has been a lot of work on the speed control of the DFIM based VSPS systems but there has not been much work on the power control of DFIM based VSPS systems.This research focuses on the decoupled active and reactive power control of the DFIM based VSPS systems. This research develops an efficient control method for Rotor Side Converter (RSC) to attain a decoupled power control while the Grid Side Converter (GSC) is used to maintain a fixed DC voltage present between RSC and GSC.In this research, PSIM has been used with Matlab/Simulink by employing SimCoupler to interface the two simulation softwares. The focus of the research is on the RSC control, which actually enables the power control of DFIM by controlling the rotor currents. A Three-Level Back-Back Power Electronic Converter is used to control the power of the DFIM in a VSPS system.