REVIEW of ENG224 / ENG424 • ELECTRIC MACHINES • P. C. Sen, Principles of Electric Machines and Power Electronics, 3rd edition, John Wiley & Sons, 2014. • Stephen J. Chapman, Electric Machinery Fundamentals, 5th edition, McGraw-Hill, 2012. • POWER SYSTEMS • Chapter 2 Section 4 • Weedy & Cory, Power System Analysis, 5th edition, John Wiley & Sons, 2012 REVIEW of ENG224 / ENG424 • TRANSFORMERS • Modelling – Equivalent circuit • Auto transformers • OLTC • Three-phase transformer connections – Yd11, Dy1, Dd6, V, Z etc • Three-winding three-phase transformers REVIEW of ENG224 / ENG424 • DC MOTORS • • • • Shunt Separately excited Series Compound – – – – Differential Cumulative Long Short • Torque-speed characteristics REVIEW of ENG224 / ENG424 • INDUCTION MOTORS • Only one supply needed • Field winding can be very simple (squirrel case) – Cheap • Intrinsic starting torque in three phase motors – Can be changed in wound-rotor units • Starting circuit for single phase motors • Equivalent circuit parameters REVIEW of ENG224 / ENG424 • ALTERNATORS • • • • Synchronous speed Synchronous reactance Synchronisation Operation of one alternator with an infinite bus – Constant power operation – Constant excitation operation • Synchronous motors REVIEW of ENG224 / ENG424 • ALTERNATORS • • • • Synchronous speed Synchronous reactance Synchronisation Operation of one alternator with an infinite bus – Constant power operation – Constant excitation operation • Synchronous motors REVIEW of ENG224 / ENG424 • PER UNIT QUANTITIES • Base MVA – Applies to the whole system • Base kV – Applies to one side of a transformer – Automatically changes on the other side according to the turns ratio. • Advantages
