PELLET PLANT STARTING TRANSIENT EFFECT AND SPEED CONTROL ON THE CONVEYOR BELT USING A SQUIRREL CAGE INDUCTION MACHINE

Abstract

The pellet plant starting transient effect and speed control on a conveyor belt using a squirrel cage induction machine is presented. A pellet is a fine-grained iron ore that is converted into balls of a certain diameter, usually 8–20 mm. A pellet plant is a set of equipment used to produce pellets. Its components consist of crushing, mixing, feeding, granulation, and cooling equipment. Materials used to produce pellets include iron ore and limestone, coke, anthracite coal, quartzite as additives, which are passed through balling disk drum, furnace, and the green pellets so formed rotary kiln as product for steel production. Electrical transient currents are current before reaching steady state and fast rise time, short duration energy pulses that commonly have voltage and current components often transmitted down power lines. This transient is a disturbance that affects the power quality of the pellet plant starting on the conveyor belt and constitutes a negative effect and damage to the pellet plant equipment. Electrical transients occur in pellet plant power systems from a variety of sources and have adverse effects on the equipment and reliability of the power system. These may be electrical transmission faults such as contact of the transmission lines with the tree, lightning, switching, and load changes. This study was conducted to ensure the operational stability of the pellet plant starting facilities after a disturbance while maintaining quality services. The pellet plant conveyor belt is a power-driven belt and is supported by metal plate rollers upon which the conveyor belt rests. It is a wrapped rounded driven pulley driven by an electrical machine. The squirrel cage machine is an induction device that harnesses electromagnetism to generate motion. It is called “squirrel cage” machine because of its rotor shape, and the inner component is connected to the output shaft that looks like a cage. With the introduction of the Squirrel cage induction machine to drive the pellet plant conveyor belt, the pellet plant conveyor belt and its associated equipment were stabilized and the negative effects were eliminated. The experimental investigation revealed that the average current of the pellet plant squirrel cage induction machine at no load characteristics was 0.703A_ac, apparent power was 220 VA_, real power was 80 W, reactive power was 201 VAR, and power factor was 0.286. With the introduction of torque at 12 (12(Ibf.in), the average current at no load characteristics was 1.29A_ac,,apparent power, 412VA, real power ,320W,  reactive power ,272var, power factor ,0.785,  horse power, 0.260, efficiency, 79.6 %. When torque was introduced at 12(Ibf.in), the starting current to full load current was 4.10, starting torque, 2.27, full load current, 0.603. There was an increase in the power factor and increase in pellet plant conveyor belt squirrel cage induction machine efficiency. When the slip dropped to some value between 2% and 10%, the speed stabilized and remained relatively constant. The operating characteristics of the squirrel cage machine are very efficient, higher full-load speed, and good speed regulation. The squirrel cage induction machine is widely used in a variety of industrial applications and should be introduced for pellet plant conveyor belt operation because its rotor construction is very simple, rugged, and cannot be burnt out. Less maintenance due to the absence of commutation brushes and slip ring. The pellet plant conveyor belt squirrel cage induction machine runs at a rotating field of 1500 r/min at 50 Hz because the excitation current increases because of lower winding impedances. These are recommended for pellet plant engineers, technicians, and operators