Water Pumping Solution with Solar Power Using ZSI Connected Induction Motor

Abstract

The aim of this paper is to present a single-stage provision for a photovoltaic based water pumping system coupled
with a three phase induction motor, employing a Z-source inverter. The system uses a ZSI to provide an output AC
voltage to the motor-pump drive. The proposed system works with a control scheme which includes Space Vector
Pulse Width Modulation (SVPWM) and Maximum Power Point Tracking (MPPT). Shoot through ratio is crucial for
boosting DC link voltage in ZSI. In this project, for the performance enhancement of ZSI, improved shoot through
envelope technique along with SVPWM control technique for the PV based ZSI fed drive is presented. The MPPT
algorithm generates Vmpp (voltage at maximum power point) which helps using the generated PV power efficiently
and obtains ‘ma‘, the modulation index which is required for the operation of the ZSI and generates AC voltage
under all environmental conditions. Moreover, the value of ‘ma’ is defined for the working frequency of the induction
motor which aids in the augmentation of the performance. As the power generated by the PV system is highly
variable due to its dependency on various parameters, ZSI with variable voltage boosting is controlled for achieving
the desired RMS voltage. Voltage boosting feature of ZSI allows for reliable operation of IM.