Design and simulation of a photovoltaic induction motor coupled water pumping system

Efficiency is the sense of energy saving is a main issue in photovoltaic pumping. The objective of this work is to design and simulate an efficient battery less pumping system powered from photovoltaic panels, comprising a new push-pull converter with Induction Motor. In a photovoltaic pump-storage system, solar energy is stored, when sunlight is available as potential energy in water reservoir and consumed according to the demand. There are advantages in avoiding the use of large banks of lead acid batteries, which are heavy and expensive and have one fifth lifetime of photovoltaic panel. The DC/DC converter used in this system is the push-pull converter. It is commonly a two-switch topology. The primary advantage of push-pull converter is their simplicity and ability to scale up to high power throughput. Hence a pumping system based on an Induction motor can be an attractive proposal to overcome the drawback with DC motor and ensure reliable, costless and maintenance-free operation. Through this approach the drawbacks during the DC motor usage are overcome and a high power throughput is obtained from the designed push pull converter as it delivers accurate output value with low power losses and less output ripple because the converter has its own filter. In this project, an efficient push-pull converter-inverter fed Induction motor is designed, modeled and simulated using MATLAB simulink. Voltage spikes generated are reduced by a simple filter circuit. Fast Fourier transforms are carried out for the currents and voltages of three phase inverter with 120° and 180° conduction modes and corresponding total harmonic distortions are calculated in simulink for the selection of suitable inverter mode. Common mode voltage is also measured to find the noise ratio. This common mode noise is reduced using a filter. Open loop and closed loop systems are simulated and the results are presented.