- #61
shaltera
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Zth=(330.3+j219)
Zl=(330.3-j219)
Zl=(330.3-j219)
Network Maximum Power Transfer Calculation
- Thread starter shaltera
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- Maximum Maximum power Power
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Discussion Overview
The discussion revolves around calculating the load impedance for maximum power transfer in a given electrical network, utilizing Thevenin's theorem. Participants explore the implications of frequency on impedance and the application of the Maximum Power Transfer Theorem (MPTT) in the context of AC circuits.
Discussion Character
- Homework-related
- Technical explanation
- Debate/contested
Main Points Raised
- One participant questions whether a given value labeled as E in the problem statement is a printing error, suggesting it should be in volts rather than hertz.
- Another participant clarifies that impedance depends on frequency, not voltage, and provides the formula for angular frequency.
- Calculations for Thevenin impedance are presented, with one participant providing specific resistance values and calculations.
- Concerns are raised about the imaginary component of inductance, with a participant emphasizing the need to consider complex impedance.
- Participants discuss the application of the MPTT, with some asserting that the load impedance should equal the Thevenin impedance, while others argue that it involves the complex conjugate of the source impedance.
- Frustration is expressed by some participants regarding the complexity of the problem and the lack of examples that match their specific circuit configuration.
- There is a suggestion to assume a unit voltage source for simplification, which some participants find confusing.
Areas of Agreement / Disagreement
Participants express various viewpoints on the application of the MPTT, particularly regarding the relationship between load impedance and Thevenin impedance. There is no consensus on the correct approach or interpretation of the problem, and multiple competing views remain throughout the discussion.
Contextual Notes
Participants note the complexity of deriving the MPTT for complex impedances compared to real-valued resistances. There is also mention of the challenge posed by the lack of a specified voltage source in the problem, which complicates the calculations.
Who May Find This Useful
This discussion may be useful for students and individuals studying electrical engineering concepts, particularly those focusing on circuit analysis, Thevenin's theorem, and the Maximum Power Transfer Theorem in AC circuits.
- #62
gneill
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shaltera said:
Okay, and how are they connected in the circuit?
- #63
shaltera
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- 0
In series
- #64
shaltera
- 91
- 0
Znet=Zth+Zl=660.6?
- #65
gneill
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shaltera said:
Yes!
Note that the reactive components have completely disappeared. The choice for ZL as the complex conjugate of Zth has ensured that the reactive components cancel each other.
So for purposes of analysis at this point, the source impedance is just a real resistance of 330Ω, and the load impedance is just a real resistance 0f 330Ω. Two resistors! Easy to analyze!
Can you find the power in that load resistor? Remember that the source voltage is Vth.
- #66
shaltera
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P=i2Rl
- #67
gneill
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That'll work; So how will you calculate the current? Remember, the load circuit now comprises the Thevenin voltage (1000/1220)E and two resistors of the same size (330 Ω).
(Actually, the notion that the two resistors form a voltage divider might give you another path to finding the power, particularly since it's a very simple voltage divider with equal value resistors...)
(Actually, the notion that the two resistors form a voltage divider might give you another path to finding the power, particularly since it's a very simple voltage divider with equal value resistors...)
- #68
shaltera
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I=Vth/(Zth+Rl)
- #69
gneill
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shaltera said:
Remember: The voltage source Vth sees ONLY the resistances. The reactive (imaginary) part of Zth has "disappeared", cancelling with the reactive part of the load impedance.
- #70
shaltera
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Zth=(330.3+j219)
Zl=(330.3-j219)
I=E(1000/1220)(330.3)
Zl=(330.3-j219)
I=E(1000/1220)(330.3)
- #71
gneill
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