Novel sliding mode control of single-stage induction motor drive for solar water pumping applications

Solar-powered water pumping systems (SPWPS) are increasingly used in remote agricultural areas where grid integration is not feasible. The main objective of SPWPS is to extract maximum power from the solar photovoltaic array (SPVA) and deliver it to the motor-pump drive. A simplified motor control scheme for the extraction of maximum power from SPVA with the induction motor drive for partial shading conditions is not presented so far. This paper proposes a vectorial sliding mode (VSM)-based field-oriented control for a single-stage induction motor drive. The VSM control is inherited with maximum power extraction algorithm for SPVA. The improved particle swarm optimization (IPSO) method is used to achieve maximum power extraction from the SPVA, even in partial shading conditions. The IPSO algorithm generates a peak power equivalent voltage reference, which is used as a torque reference for the VSM control (VSMC). The VSMC control is developed in complex valued form to eliminate the need for Clark and Park transformations and thus reducing the order of the system. VSMC incorporates sensorless features, eliminating the need for speed and voltage sensors at the motor terminals. The proposed system is investigated for change in insolation of SPVA that works for partial shading conditions also. The IPSO algorithm is compared with the incremental conductance and particle swarm optimization algorithms, showing the superiority of IPSO method in the peak power tracking accuracy. The IPSO-VSMC algorithm through hardware prototype achieves maximum power tracking accuracy between 87.1 and 93.71% for the most possible insolation cases with partial shading conditions.