Concept explainers
Assume the system shown in Fig. 12.34 is balanced, Rw = 0, , and a positive phase sequence applies. Calculate all phase and line currents, and all phase and line voltages, if Zp is equal to (a) 1 kΩ; (b) 100 + j48 Ω; (c) 100 − j48 Ω.
(a)
All the line and phase currents and all the line and phase voltages for the given load impedance.
Answer to Problem 17E
The line and phase currents in sequence are
Explanation of Solution
Given data:
The resistance of the wire
The phase to neutral voltage
The load impedance
Calculation:
The system follows positive sequence hence the phase to neutral voltages will be,
For phase
For phase
The required diagram is shown in Figure 1.
The line voltage between phase
Substitute
The system follows positive sequence hence the line to line voltages will be,
All the phase and line voltages are independent of the impedance value and hence these values will remain same for all the values of load impedance
The conversion from
Hence, the load impedance
Since the given system is a star connected system, the phase currents will be equal to the line currents.
The phase
Here,
The phase
Substitute
The phase
Here,
The phase
Substitute
The phase
Here,
The phase
Substitute
Conclusion:
Therefore, the line and phase currents in sequence are
(b)
All the line and phase currents and all the line and phase voltages for the given load impedance.
Answer to Problem 17E
The line and phase currents in sequence are
Explanation of Solution
Given data:
The load impedance
Calculation:
All the phase and line voltages are independent of the impedance value and hence these values will remain same for all the values of load impedance
The phase
Here,
The phase
Substitute
The phase
Here,
The phase
Substitute
The phase
Here,
The phase
Substitute
Conclusion:
Therefore, the line and phase currents in sequence are
(c)
All the line and phase currents and all the line and phase voltages for the given load impedance.
Answer to Problem 17E
The line and phase currents in sequence are
Explanation of Solution
Given data:
The load impedance
Calculation:
All the phase and line voltages are independent of the impedance value and hence these values will remain same for all the values of load impedance
The phase
Here,
The phase
Substitute
The phase
Here,
The phase
Substitute
The phase
Here,
The phase
Substitute
Conclusion:
Therefore, the line and phase currents in sequence are
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Chapter 12 Solutions
Loose Leaf for Engineering Circuit Analysis Format: Loose-leaf
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