Solar Energy Fluctuations Research Articles

Vectorial Command of Induction Motor Pumping System Supplied by a Photovoltaic Generator

Vectorial Command of Induction Motor Pumping System Supplied by a Photovoltaic GeneratorWith the continuous decrease of the cost of solar cells, there is an increasing interest and needs in photovoltaic (PV) system applications following standard of living improvements. Water pumping system powered by solar-cell generators are one of the most important applications. The fluctuation of solar energy on one hand, and the necessity to optimise available solar energy on the other, it is useful to develop new efficient and flexible modes to control motors that entrain the pump. A vectorial control of an asynchronous motor fed by a photovoltaic system is proposed. This paper investigates a photovoltaic-electro mechanic chain, composed of a PV generator, DC-AC converter, a vector controlled induction motor and centrifugal pump. The PV generator is forced to operate at its maximum power point by using an appropriate search algorithm integrated in the vector control. The optimization is realized without need to adding a DC-DC converter to the chain. The motor supply is also ensured in all insolation conditions. Simulation results show the effectiveness and feasibility of such an approach.

Vectorial command of an asynchronous motor fed by a photovoltaic generator

In order to promote renewable energy, Tunisia has developed a large program to exploitate photovoltaïc systems (PV) to provide electric power in rural electrification. These needs increase continually following standard of living improvements, from lighting and media communication (radio, TV) to motors, refrigeration and pumping. The fluctuation of solar energy on one hand, and the necessity to optimise available solar energy on the other, it is useful to develop new efficient and flexible modes to control motors. A vectorial control of an asynchronous motor fed by a photovoltaïc system is proposed. In this case, the control of the circulating current becomes an important objective in the algorithm design. This paper presents an efficient current controller scheme that can achieve high accuracy and a fast dynamic response of induction machine. This scheme uses voltage decoupling and proportional integral controller loops (PI). Furthermore, to operate the PV array at its maximum power point for every instant, the PV system must contain a maximum power point tracking controller (MPPT). Good static and dynamic performances were obtained in simulation of the proposed structure.