Sliding mode application in speed control of an induction machine coupled in a hydraulic system

In this paper, a nonlinear control of an induction motor (IM) supplied with a photovoltaic generator to assure the level control of two coupled tanks is designed. The global system is decomposed into two separate models thus, coupled are assured by discontinuous command. In the first step, we propose a sliding mode technique to make the speed and the flux control of the IM robust to parameter variations. Then, the aim consists to assure the stability of the system autonomously towards a desired state (water level), by varying the speed of the IM. The use of the nonlinear sliding mode method provides very good performance for motor operation and robustness of the control law despite the external/internal perturbation. Simulation results are given to highlight the performance of the proposed control technique under load disturbances and parameter uncertainties.   Key words: Sliding mode control, photovoltaic energy, water level, coupled reservoirs, induction motor-pump.