TEST 2SMJE 2103 (Electrical Power System)December 20, 2013Q1. A 3-phase induction motor having a synchronous speed of 1200 rpm draws 80 kW from 3-phase feeder. The copper losses (PSCL) and core losses (Pcore) in the stator amount to 5 kW. Ifthe motor runs at 1152 rpm, calculate the following:a)The active power transmitted to the rotor (PAG)[3 marks]b)The rotorI2Rlosses (PRCL)[3 marks]c)The mechanical power developed (Pconv)[3 marks]d)The mechanical power delivered to the load (Pout), knowing that the windage, friction andstray losses are equal to 2 kW[3 marks]e)The efficiency of the motor[3 marks]Q2.Both parties from electrical power utilities and users are looking for save and clean powersupply due to keeping safety installed equipment and customer’s appliances. However, thepower delivering system obviously exposes to schedule and unscheduled disturbances andfacing power quality (PQ) problems. Please describe the following PQ problems with theircauses and consequences:a)Voltage sags[5 marks]b)
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Electric motor,utm international campus,International Institute of Technology,Dr. Rasli