Concept explainers
Consider the wye-delta system shown in Fig. 12.60. Let
Find the phase and line currents for the
Answer to Problem 51P
The phase currents
The line currents
Explanation of Solution
Given data:
Refer to Figure 12.60 for the
In the Y-connected source:
The line to neutral voltage
The line to neutral voltage
The line to neutral voltage
In the delta-connected unbalanced load:
The impedance
The impedance
The impedance
Formula used:
Write the expression to find the line to line voltage
Here,
Write the expression to find the line to line voltage
Here,
Write the expression to find the line to line voltage
Here,
Write the expression to find the line to line current
Here,
Write the expression to find the line to line current
Here,
Write the expression to find the line to line current
Here,
Write the expression to find the line current
Here,
Write the expression to find the line current
Here,
Write the expression to find the line current
Calculation:
Re-draw the given Figure 12.60 as follows.
Substitute
Substitute
Substitute
Substitute
Substitute
Substitute
Or
Thus, the phase currents are,
Substitute
Substitute
Substitute
Thus, the line currents are,
PSpice simulation:
Assume the angular frequency
Write the expression to find the capacitive reactance.
Substitute
Write the expression to find the inductive reactance.
Substitute
Draw the circuit as shown in Figure 2 in PSpice, connect the
Provide the Simulation settings as in Figure 2.
Now, run the simulation and check the output file in newly opened PSpice A/D window.
From the PSpice results the phase currents are,
FREQ IM(V_IAB) IP(V_IAB)
1.5916E-01 2.0785E+00 1.2000E+02
FREQ IM(V_IBC) IP(V_IBC)
1.5916E-01 2.0785E+00 9.0000E+01
FREQ IM(V_ICA) IP(V_ICA)
1.5916E-01 2.0785E+00 1.5000E+02
The phase current
The phase current
The phase current
From the PSpice results the line currents are,
FREQ IM(V_IaA) IP(V_IaA)
1.5916E-01 1.0759E+00 4.5000E+01
FREQ IM(V_IbB) IP(V_IbB)
1.5916E-01 1.0759E+00 1.5000E+01
FREQ IM(V_IcC) IP(V_IcC)
1.5916E-01 2.0785E+00 -1.5000E+02
The line current
The line current
The line current
Conclusion:
Thus,
The phase currents
The line currents
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Chapter 12 Solutions
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