A Global Stability of Linearizing Control of Induction Motor for PV Water Pumping Application

Abstract

This article describes how a field oriented control can provide the same performance as it is achieved by a DC motor. However, this technique requires a mechanic sensor and is very sensitive to the variation of motor parameters which results in an undesirable coupling between the flux and the torque. To solve these problems, this paper proposes a global stability and robust nonlinear controller, applied to induction motor (IM), in order to achieve an exact decoupling between speed and flux for all motor operating conditions. The induction motor is coupled with a centrifugal hydraulic pump, powered by a photovoltaic array speeding system. The proposed system is designed for usage in rural areas or remote electricity needs in absence of the grid network. A nonlinear controller adjusts the motor speed reference to attain the maximum power point (MPPT). In presence of rotor and stator resistances and irradiation disturbance the results obtained by simulations confirm the effectiveness of the proposed method.