Single-Stage PV-Grid Interactive Induction Motor Drive With Improved Flux Estimation Technique for Water Pumping With Reduced Sensors

This article deals with a photovoltaic-grid integrated system operating an induction motor (IM) coupled to a water pump. A simple dc-link voltage regulation approach is adopted for the power transfer. This system is utilized to primarily feed the induction motor-driven water pump and when water pumping is not desired, the power is delivered to the utility. This system requires two current sensors and two voltage sensors in total for sensing and estimation purpose. Induction motor phase currents are estimated from dc-link current by modified space vector modulation (SVM) technique. The speed estimation in this system is achieved by artificial neural network-based model reference adaptive system with a third-order integrator for flux estimation and is capable of controlling the power flow as per demand. The field-oriented control is used for speed control of an IM-pump. A third-order integrator based unit voltage generation algorithm is used to control the power transfer in both the direction between utility and the IM drive with water pump by regulating dc-link voltage. The appropriateness of the system is justified by simulated results on MATLAB/Simulink platform and test results procured with the help of a developed prototype during varying solar irradiances.