International Journal of Automation and Power Engineering, 2012, 1: 23-28 - 23 - Published Online May 2012 www.ijape.org 1. INTRODUCTION Agriculture is still a major occupation in India as majority of its population is concentrated in rural areas. Population explosion is creating a heavy demand for food grains in the country; hence, the role of farmers in improving the food grain situation of the country acquires prominence. It is therefore needless to say that farmers form the backbone of our country. A farmer therefore needs to be supported in all ways to provide maximum grain output with minimum efforts. Though the government has taken up many irrigation projects to provide canal irrigation, the coverage area is restricted due to geographical and economical reasons. Earlier farmers used diesel engine coupled pumps for irrigation purposes; the mounting pressure of oil crisis forced them to use electric motors. Electricity being clean as well as economical became a dependable source of power for irrigation. As an incentive many state governments provide electricity at subsidized rates to farmers for their irrigation pumps. These pumps have helped farmers to a large extent in irrigating their farm lands. Electric motors used for pumps can provide years of trouble free service when properly selected, operated and maintained. Since induction motors are quite popular in this sector, it is quite important to carry out studies about the effects of power quality on the efficiency and reliability of induction motors. In induction motors, both the stator and rotor have laminated cores and if the core material is judiciously chosen, iron losses can be greatly minimized. If high quality copper wire is used in the stator windings then copper losses will be minimum. Squirrel cage rotors have aluminum cast into the rotor slots for better performance. Induction motors available in the market are tailor made as per requirements of industrial sector wherein the starting torque requirements are usually large. Induction motors used in agricultural sector require normal starting torque, which leads to considerable improvement in full load running performance of motor and offsets the extra cost of starting equipment. The pump load usually varies between 60 – 100% and sustains over a longer period of time, hence induction motors with flat topped efficiency curves are recommended for varying loads with low iron losses. When quality core (Abstract) AC motors have gained wide ranging applications in the present day scenario. Adoption of innovatively designed speed control mechanisms in the industrial sector has revolutionized these drives. Now-a-days the industrial sector has a well organized power supply system, wherein motors used for specific industrial applications are not subjected to abrupt supply variations. Thus their operating conditions remain nearly the same throughout their life span. There are certain areas like the agricultural sector which use AC motors without any speed control mechanisms. In the agricultural sector, water pumps are used for irrigating small tracts of land from tube wells or open wells. Small and marginal farmers with lands along the banks of rivers have open wells even today with irrigation pumps. The three phase AC motors which are coupled to these pumps are subjected to a wide power supply voltage fluctuations depending on their distance from the distribution transformers. Supply voltages at motor terminals are never constant throughout the day and night. They are subjected to wide voltage fluctuations during different periods of the day and night. The most common problem faced by farmers is the burnout of motors. In order to ascertain the main reasons for burnout of motors used in irrigation pumps and observe their performance under variable supply voltage and load conditions, an experimental model was set up in the laboratory and relevant tests were carried out by simulating field conditions. It was observed from experimental results that with higher and lower values of supply voltage to the motor, the current drawn was higher and resulted in increased losses thereby creating higher thermal stresses. The basic idea of reducing losses could be achieved by using good quality core and conductor material for the motor, which would minimize thermal stresses. It could be finally summarized that an Energy efficient induction motor as per specific needs of the agricultural sector has to be designed and manufactured keeping the cost factor in mind. Keywords: Simulation, Performance of Motors, Supply Voltage Variations, Induction Motors, Irrigation Pumps Simulation and Testing of Induction Motors Used with Irrigation Pumps K.S.Jairaj, K.Srikant School of Engineering, Chamelidevi Group of Institutions, Khandwa Road, Indore – 452020, India. Email: ksjairaj123@gmail.com, acadshead@gmail.com