I = Using the 'single phase equivalent circuit' given below, the required parameters ir terms of motor parameters equations will be deducted. Equations separately for asynchronous motor powered by voltage source will be removed and the spaces given below will be written. V1 and 11 are the RMS value of the AC phase voltage and current. All formulas (3phase motor) will be written as a function of motor Stator current Rotor current I = Pm = Shaft power parameters and slip. Moment Tm = j(X;+X2) V1 = Yield Thevenin emp. Zth = Simplified Approximate Equivalent Circuit Thevenin voltage Vth = Slip at maximum Smax = moment point Max. moment Tmax = Maksimum yield 1 max %3D İnrush current Istart = (s=1 current) İnrush moment Tstart =

Q3/ Two 50 Hz generators of rating 100 MW and 300 MW are operating in parallel. Each of them has a speed regulation of 5%. They supply a total load of 320 MW. Assume that the speed changers are set to give rated frequency at 100% rated output power. Determine the output power of each generator and the operating frequency.

With the aid of diagrams describe the basic topology of a wound field 3 phase synchronous generator and outline the relationship between the excitation voltage and rotor current. Q2 (a) (b) Outline with the aid of a suitable diagram the necessary power conversion stages required to interface a small permanent magnet (PM) generator to a stand alone DC system. A star connected 3 phase wound field synchronous generator with a synchronous reactance of 20 N is connected to a 6.6 kV (phase voltage) grid and supplies 1.5 MW at 0.95 lagging power factor at its terminals. Calculate the phase current and resultant voltage across the synchronous reactance (Vxs), and from a scaled phasor diagram graphically determine the required excitation voltage (Eph) and load angle (8). (c) The load is now increased to 3 MW with the Excitation Voltage kept constant. Using the phasor diagram drawn in part (c) graphically determine the resultant phase current, power factor and load angle. (d)

Q2. a) A 415V, 50Hz, 3-phase induction motor supplies its rated power to a load. The rated speed of the motor is 980 rpm. b) Two synchronous generators, G2 and G2, are connected parallelly supplying a load. Generator G1 has a no-load frequency of 50.5 Hz and a slope of 300 MW/Hz. Generator G2 has a no-load frequency of 50.2 Hz and a slope of 500 MW/Hz. The load consumes 250 MW real power. (i) At what frequency does this system operate, and how much power is supplied by each of the two generators? (ii) An additional 100 MW load is added to this power system. What is the new system frequency, and how much power do G1 and G2 supply? (iii) The governor set point of G2 is changed to control system frequency back to 50 Hz. Determine the G2 governor set point.

G1. The terminals of a DC motor are identified as the same as those of a DC generator. a) true b) false G2. What are the standard identification letters for the armature winding of a DC compound motor? a) A1 and A2 b) S1 and S2 C) F1 and F2 d) none of the above G3. What are the standard identification letters for the series field winding of a DC compound motor: a) A1 and A2 b) 1I and S2 c) F1 and F2 d) none of the above