ELECTRIC MACHINERY FUNDAMENTALS: PART 1

TRANG 3 TABLE OF CONTENTS CHAPTER 1: INTRODUCTION TO MACHINERY PRINCIPLES 1 CHAPTER 2: TRANSFORMERS 23 CHAPTER 3: INTRODUCTION TO POWER ELECTRONICS 63 CHAPTER 4: AC MACHINERY FUNDAMENTAL[r]

The Formula Lightning electric race car competition is an interuniversity 2 competition project that has been active since 1994. This project involves the design, analysis, and testing of an electric open-wheel race car. A photo and the generic layout of the car are shown in Figures 1.[r]

Note that after D 1 turns on, capacitor C discharges through it and the gate of the SCR. At the end of the half cycle, the voltage on the capacitor is again essentially 0 volts, and the whole process is ready to start over again at the beginning of the next half cycle.
To determi[r]

_ _c Assume that the primary voltage of this transformer bank is a constant 13.8 kV, and plot the secondary _ voltage as a function of load current for currents from no-load to full-load[r]

SOLUTION At the beginning of each half cycle, the voltages across the PNPN diode and the SCR will both be smaller then their respective breakover voltages, so no current will flow to the load (except for the very tiny current charging capacitor C), and v load (t) will be 0 volts. However, capaci[r]

Zinc Oxide EAFD : Electric Arc Furnace Dust part 1
Zinc Oxide EAFD : Electric Arc Furnace Dust part 1
Zinc Oxide EAFD : Electric Arc Furnace Dust part 1
Zinc Oxide EAFD : Electric Arc Furnace Dust part 1
Zinc Oxide EAFD : Electric Arc Furnace Dust part 1

SOLUTION There are three regions in this core. The top and bottom form one region, the left side forms a second region, and the right side forms a third region. If we assume that the mean path length of the flux is in the center of each leg of the core, and if we ignore spreading at the corners[r]

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Appendix C: Salient Pole Theory of Synchronous Machines
C-1. A 480-V 200-kVA 0.8-PF-lagging 60-Hz four-pole Y-connected synchronous generator has a direct-axis reactance of 0.25 Ω , a quadrature-axis reactance of 0.18 Ω , and an armature resistance of 0.03 Ω . Friction, windag[r]

A lecture for electric power machinery A lecture for electric power machinery A lecture for electric power machinery A lecture for electric power machinery A lecture for electric power machinery A lecture for electric power machinery A lecture for electric power machinery A lecture for electric powe[r]

Chapter 6 : Synchronous Motors
6-1. A 480-V, 60 Hz, four-pole synchronous motor draws 50 A from the line at unity power factor and full load. Assuming that the motor is lossless, answer the following questions:
(a) What is the output torque of this motor? Express the answer both[r]

All losses except the dc machine’s armature resistance may be neglected in this problem. Assume that the magnetization curves of both machines are linear.
(a) Initially, the ac machine is supplying 50 kVA at 0.8 PF lagging to the ac power system. 1. How much power is being supplied to[r]

(e) If the motor is now unloaded with no changes in terminal voltage or R adj , what is the no-load speed of the motor?
(f) Suppose that the motor is running at the no-load conditions described in part (e) . What would happen to the motor if its field circuit were to open? Ignorin[r]

S OLUTION
(a) The phase voltage at starting would be 1 / 3 = 57.7% of the phase voltage under normal running conditions.
(b) Since the phase voltage decreases to 1 / 3 = 57.7% of the normal voltage, the starting phase current will also decrease to 57.7% of the normal[r]

X X
X
≈ =
7-13. Figure P7-1 shows a simple circuit consisting of a voltage source, two resistors, and two reactances in parallel with each other. If the resistor R L is allowed to vary but all the other components are constant, at what value of R L will the maximum possible power[r]

(d) Calculate the real power P and reactive power Q supplied or consumed by the machine under the
conditions in part (c). Is the machine operating within its ratings under these circumstances? S OLUTION
(a) This machine is a generator supplying real power to the power system, becau[r]

Note: An electronic version of the saturated open circuit characteristic can be found in file p52_occ.dat , and an electronic version of the air-gap characteristic can be found in file p52_ag_occ.dat . These files can be used with MATLAB programs. Column 1 contains field current in am[r]

4-6. If an ac machine has the rotor and stator magnetic fields shown in Figure P4-1, what is the direction of the induced torque in the machine? Is the machine acting as a motor or generator?
S OLUTION Since τ ind = k B R × B net , the induced torque is clockwise, opposite the direct[r]

3. Page 62, Problem 1-19, should state: “Figure P1-14 shows a simple single-phase ac power system with three loads. The voltage source is V = 120 0 V ∠ ° , and the three loads are …”
4. Page 64, Problem 1-22, should state: “If the bar runs off into a region where the flux de[r]

(c) The field current of generator 1 should be increased, and the field current of generator 2 should be simultaneously decreased.
5-25. A generating station for a power system consists of four 120-MVA 15-kV 0.85-PF-lagging synchronous generators with identical speed dr[r]

S OLUTION At the beginning of each half cycle, the voltages across the DIAC and the SCR will both be smaller then their respective breakover voltages, so no current will flow to the load (except for the very tiny current charging capacitor C), and v load (t) will be 0 volts. However, capacitor[r]