Adaptive d-Axis Current Control of RSyM for Photovoltaic Water Pumping Incorporating Cross Saturation

In this project, an adaptive d-axis current control of a Reluctance Synchronous Motor (RSyM) drive for Photovoltaic (PV) water pumping system, which incorporates impacts of cross saturation in real time to compensate the errors in the speed estimation is proposed. The response of the RSyM drive, is optimized by adaptive d-axis current estimation. A real-time assessment of d-axis inductance is carried out to include the cross magnetization into consideration for improving the efficiency of the motor. The d-axis current is varied for minimum value to provide maximum output torque. 

Here, a Two-Stage Solar Energy Conversion System (SECS) is used to drive centrifugal pump coupled to an RSyM drive. A boost converter is used to optimize the PV power using an Incremental Conductance (IC) based Maximum Power Point Tracking (MPPT) technique. The control of RSyM, is implemented using the adaptive id-based vector control algorithm. 

An adaptive d-axis current is fed to the controller corresponding to the available solar irradiation, which aids in the maximization of drive efficiency and minimization of stator copper losses. Moreover, this control improves the motor input terminal power factor. A speed/position sensor-less control technique is utilized to reduce the complexity and to enhance the reliability of water pumping system. The feasibility of the proposed control scheme has been verified by simulation in MATLAB/SIMULINK.

Keywords: Adaptive d-axis current control, Reluctance Synchronous Motor, Photovoltaic (PV), water pumping system, Two-Stage Solar Energy Conversion System, A speed/position sensor-less control.