1 Electrical Machines EELE 4350 Dr Assad AbuJasser

1 Electrical Machines (EELE 4350) Dr. Assad Abu-Jasser, EE Department-IUGAZA Electrical Machines (EELE 4350)

2 Assad Abu-Jasser, Ph. D Electric Power Engineering site. iugaza. edu. ps/ajasser@iugaza. edu. ps Dr. Assad Abu-Jasser, EE Department-IUGAZA Electrical Machines (EELE 4350)

3 Chapter One Review of Single- and Three-Phase Circuits Dr. Assad Abu-Jasser, EE Department-IUGAZA Electrical Machines (EELE 4350)

4 Single-Phase AC Current Dr. Assad Abu-Jasser, EE Department-IUGAZA Electrical Machines (EELE 4350)

5 Voltage, Current & Instantaneous Power Dr. Assad Abu-Jasser, EE Department-IUGAZA Electrical Machines (EELE 4350)

6 Complex Power Dr. Assad Abu-Jasser, EE Department-IUGAZA Electrical Machines (EELE 4350)

7 Example 1. 2 Time domain and Frequency domain Find the current in the circuit shown. Draw the power diagram and the phasor diagram, and sketch the input voltage and the current in time domain. Dr. Assad Abu-Jasser, EE Department-IUGAZA Electrical Machines (EELE 4350)

8 Example 1. 2 Phasor diagram and Power diagram Dr. Assad Abu-Jasser, EE Department-IUGAZA Electrical Machines (EELE 4350)

9 Three-Phase Circuits Y-Connected Source Dr. Assad Abu-Jasser, EE Department-IUGAZA Electrical Machines (EELE 4350)

10 Three-Phase Circuits Δ-Connected Source Dr. Assad Abu-Jasser, EE Department-IUGAZA Electrical Machines (EELE 4350)

11 Voltage Waveforms Positive Sequence Dr. Assad Abu-Jasser, EE Department-IUGAZA Electrical Machines (EELE 4350)

12 Phase and Line Voltages Y-connected Positive Sequence Source Dr. Assad Abu-Jasser, EE Department-IUGAZA Electrical Machines (EELE 4350)

13 Phase and Line Currents Δ-Connected Source Dr. Assad Abu-Jasser, EE Department-IUGAZA Electrical Machines (EELE 4350)

14 Y- and Δ-Connected Loads Dr. Assad Abu-Jasser, EE Department-IUGAZA Electrical Machines (EELE 4350)

15 3 -φ Circuit Analysis Example 1. 4 A balanced three-phase, 866 -V, 60 -Hz, Y-connected source feeds a balanced, deltaconnected load via a 100 -km long three-wire transmission line. The impedance of each wire of the line is 1+j 2 ohms. The per phase impedance of the load is 177 -j 246 ohms. If the phase sequence is positive, determine the line and the phase currents, the power absorbed by the load, and the power dissipated by the transmission line. Dr. Assad Abu-Jasser, EE Department-IUGAZA Electrical Machines (EELE 4350)

16 1 -φ Power Measurement Dr. Assad Abu-Jasser, EE Department-IUGAZA Electrical Machines (EELE 4350)

17 Example 1. 6 1 -φ Power Measurement Two loads are connected in parallel via a transmission line to a 117 -V, single-phase ac generator as shown. A wattmeter, voltmeter, and ammeter are connected at the load site to obtain the power consumed by the load and its power factor. Determine: (a) the readings of the three meters and (b) the power factor of the load. Dr. Assad Abu-Jasser, EE Department-IUGAZA Electrical Machines (EELE 4350)

18 3 -φ Power Measurement Dr. Assad Abu-Jasser, EE Department-IUGAZA Electrical Machines (EELE 4350)

19 3 -φ Power Measurement 2 -Wattmeter Method Dr. Assad Abu-Jasser, EE Department-IUGAZA Electrical Machines (EELE 4350)

20 Example 1. 7 2 -Wattmeter Method A balanced three-phase, 1351 -V, 60 -Hz, ∆-connected source with a negative phase sequence feeds a balanced Y-connected load with a perphase impedance of 360+j 150 as shown. What is the readings on the two watt-meters? Compute the total power and the power factor of the load. Dr. Assad Abu-Jasser, EE Department-IUGAZA Electrical Machines (EELE 4350)

21 Example 1. 8 A circuit consists of series-parallel combinations of unknown resistors, inductors, and capacitors. When a 60 -Hz voltage was impressed upon the circuit, the voltmeter, ammeter, and wattmeter readings were 120 V, 5 A, and 480 W. Using a dual-channel oscilloscope, the current was found to lead the applied voltage. Represent the unknown circuit by its series and parallel equivalent circuits. Dr. Assad Abu-Jasser, EE Department-IUGAZA Electrical Machines (EELE 4350)

22 Example 1. 9 A balanced three-phase induction motor consumes 3246 W when the line voltage is 208 V and the line current is 10. 6 A. Represent the motor by its four equivalent circuits. Dr. Assad Abu-Jasser, EE Department-IUGAZA Electrical Machines (EELE 4350)

23 End of Chapter One Dr. Assad Abu-Jasser, EE Department-IUGAZA Electrical Machines (EELE 4350)