Modelling, simulation and control of an isolated pumping system powered by renewable energy sources

Abstract

In this thesis are addressed the issues specific to the field of pumping systems (PS) powered by renewable energy sources (RES). After a brief review of the state-of-the-art of the research in the field, it is addressed the modelling of an isolated PS powered by photovoltaic or wind energy conversion systems (PECS or WECS). It has been developed, implemented and validated the customized control structures for driving the induction motor of a centrifugal pump at fixed (nominal) speed using a soft starter, and at variable speed, variable discharge (flow rate), variable pressure (pumping head) or variable power absorption using a variable frequency drive. Based on these customized control structures, the control strategies of a PS powered by PECS or WECS were developed and implemented for driving the PS so that its absorbed power tracks the power produced by the PECS or WECS at partial load and controls the pressure (pumping head) of the PS according to its reference at full load. A monitoring system is developed and implemented to determine the performance of a PS powered by a PECS that measures and stores the transducers values using a non-intrusive acquisition and logging system. At the end of the thesis, the performances and contributions brought by the proposed control structures and strategies are determined based on the simulations results and the data collected with the proposed monitoring system.