A single-stage solar PV power fed Open-End Winding Induction Motor pump drive with MPPT

Abstract

In this paper a single-stage solar Photo Voltaic (PV) system feeding the power to an Open-End Winding Induction Motor (OEWIM) via a dual-inverter is presented. The OEWIM is coupled to a centrifugal pump for water pumping application. The dual-inverter fed OEWIM is chosen, as it requires low debus voltage which helps in optimal arrangement of PV modules, which could avoid large strings. In the proposed system a single PV source is connected to both the inverters, which results in zero-sequence current and hence the harmonics in the system. So as to nullify the zero-sequence current in the average sense Sample-Averaged Zero-sequence Elimination (SAZE) Pulse Width Modulation (PWM) technique is adopted. This algorithm ensures the clamping of one of the inverter when the other is being switched; this reduces the switching losses and efficiency may increase which is important factor to be considered in PV system. Also the above algorithm reduces the current ripple at higher modulation indices. The modulation index is tuned by using Maximum Power Point Tracking (MPPT) algorithm for the variations in the insolation and ambient temperature. The detailed explanation of the control algorithm for the proposed system and its simulation results under different environmental conditions are presented.