ELECTRICAL TECHNOLOGY

a) Electrical Power Measurement - Measurement of active and reactive power in three phase balanced loads by using one wattmeter and two wattmeter, Effect of power factor on wattmeter reading. b) Electrical Energy Measurement - Single phase and three phase energy meter (Construction and working), Use of CT and PT for measurement of Power / Energy in single phase and three phase system (Theoretical treatment only), Standard specifications of single and three phase energy meter. c) Tariff - Introduction, Objectives and details of H.T. and L.T tariff, TOD tariff, Advantages and improvement of power factor (Theoretical treatment only) d) Illumination - Various terms related to illumination, Types and requirement of good lighting scheme, Special purpose lighting. a) Single Phase Transformer - Types, KVA rating, Approximate equivalent circuit, Voltage regulation and efficiency of transformer, Condition for maximum efficiency. b) Three Phase Transformers - Types of transformer connection (star/star, star/delta, delta/star and delta/delta) and applications based on connections. (Theoretical treatment only) Introduction of power transformer, Distribution transformer, Study of typical distribution transformer substation, Specifications of transformer (KVA rating, Voltage ratio, Current rating). c) Three Phase Induction Motor - Constructional feature, Working principle of three phase induction motors, Types; Torque equation, Torque slip characteristics; Power stages; Efficiency; Types of starters; Methods of speed control and industrial applications. a) Single Phase Induction Motors - Types, Construction, Working principle of split phase and shaded pole type induction motors, Applications. Specifications of induction motors (KW rating, Rated voltage, Current rating, Frequency, Speed, Class of insulation) b) Synchronous Generator - Constructional features (Salient and non-salient), Working principle, e.m.f. equation, Synchronous speed of an alternator, Concept of synchronous reactance and impedance, Phasor diagram of loaded alternator, Voltage regulation of alternator by direct loading method and synchronous impedance method. Specifications of synchronous generator. D.C. Machines Construction, Working principle of D.C. generator, e.m.f. equation of D.C. generator. (Theoretical concept only). Working principle of D.C. motor. Types of D.C. motor, Back e.m.f. , Torque equation for D.C. motor, Characteristics of D.C. motor (Series, shunt and compound), Starters of D.C. shunt and series motor, Methods for speed control of D.C shunt and series motors, Industrial applications. Special Purpose Motors - Construction, Working principle, Characteristic and applications of stepper motors, A.C. and D.C. servomotors, Universal motors, Industrial applications. SCR - Construction detail, V-I characteristics, Methods to turn ON, Switching action during ON and OFF, Specification, Concept of commutation of SCR. Applications. DIAC - Construction, V-I characteristics. TRIAC - Construction, V-I characteristics, Turning ON process. MOSFET - Construction, Transfer characteristics, Output characteristics, Methods to turn ON and OFF, Applications. IGBT- Construction detail, Transfer characteristics, Output characteristics, Methods to turn ON and OFF, Applications. GTO - Construction,Working and characteristic. Drives - Advantages of electrical drives, Individual and group drives, Selection of drives depending on load characteristics. Speed Control - Single phase full converter fed D.C. drives, Three phase converter fed D.C. drives, Chopper drives, Two quadrant and four quadrant chopper drives, Stator voltage control of three phase induction motor, Frequency control of three phase induction motor, V/F control of three phase induction motor.