Questions tagged [real-power]

Power dissipated by a load is referred to as true power. True power is symbolized by the letter P and is measured in the unit of Watts (W). The formula for Real power is I²*R or V²/R.

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2answers
80 views

Is reactive power periodic in nature? What is the exact difference between active power, average power, and real power?

Consider an RC circuit which is supplied by a sine source $$v(t)=V_m\cdot \sin(\omega t)$$ The current through the circuit will be $$i(t)=I_m\cdot \sin(\omega t+\phi) \\ \phi=\arctan \left(\dfrac{1}{\...
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Do circuit breakers trip on Apparent or True Power?

The thermal and magnetic protection for AC circuit breakers take into account both the timing and the magnitude of the AC current passing through. Does a standard circuit breaker trip on the current ...
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91 views

What is the significance of UPS output Power Factor?

A UPS's output rating is shown as (2000VA/1800W). I understand that the p.f. here is 0.9. But the device or load I will connect to the UPS might have pf<0.9 or pf=1 (for light bulb). From my ...
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What are the exact meanings of reactive and apparent powers? Do we say they are supplied or consumed?

(The following doubt is from the topic of Sinusoidal Steady-State Analysis of electrical circuits) I understand the meaning of real power - it is the average power consumed (or delivered) by an ...
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94 views

Where am I wrong about my calculation of power loss?

The power loss of circuit is \$16kW\$ when the power factor, PF, is 0.6 lag. Now if I improve the PF from \$0.6\$ lag to \$0.8\$ lag, what is the power loss now? The solution provide me the formula ...
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2answers
250 views

Is there a mathematical proof that reactive power regulates voltage?

So after studying the power triangle and trying to conceptualize real power and reactive power, I seem to have come across a contradiction, at least in my own head. Most explanations disregard ...
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1answer
203 views

Reactive vs Real Power in DC-DC Converters

I don't understand which form of power, reactive or real, should be dominant in a maximally efficient DC-DC boost converter. As the circuit charges the inductor, the current and voltage will be out ...
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1answer
177 views

Tool for measuring Real and Reactive Power [closed]

I am currently doing a project where I need the Real power (P) and Reactive power(Q) measurement for a Refrigerator. I understand that if I can measure AC Voltage(V) and AC Current(A) for the ...
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1answer
400 views

What is Real Power (AC circuit)?

I've beenstudying Real(True), Active and Apparent power in AC circuit. I have understood all the concepts including phasor diagram, lagged sinusoidal waveform,the relationship between those three ...
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0answers
770 views

Calculating the real and reactive power of a transmission line

I have a single machine connected to an infinite bus with the following parameters: Sending end power = 3.75MW RL=5.18 ohms XL=130 ohms VS (Generator bus)=161kV VR (Infinite bus)=161kV Sending end ...
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2answers
328 views

What is the power factor of a classical power supply?

What is the power factor of a classical power supply ? I mean a transformer, rectifier and filter capacitor. Is it constant ?
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297 views

Complex power, real power

Given: \$U_q = 220 V, f = 50 Hz, R_i=10 \Omega, R_a=40 \Omega, L_a=95.5 mH\$ I'm asked to determine the real power transformed in \$Z_a\$. Here I break down the formulas that I use: \$Z_{total}=Z_{...
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Using Reactive vs Real Power to Manage Distribution System Voltages

This is my first post. The introduction of photovoltaics (PV) on the electrical distribution system creates changes to real power, resulting in voltage fluctuations. Those voltage fluctuations can ...
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417 views

Why do these equations prove that power factor is constant for all circuits in case of sine wave?

I know that I'm missing something but I don't know what I'm missing. Power factor is the ratio between real power and apparent power. So, I will get the equations of real power and apparent power ...
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3answers
2k views

calculating the average power using the oscilloscope

I am trying to measure the real power of an inductor, and in the manual it is said that I have to connect a resistor with low resistance to the inductor and then see the voltage difference between the ...
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1answer
1k views

How to derive apparent power formula for three phase AC system?

I know that the total power output of a three phase system is √3 EI cosØ Where E and I are the line voltage and line current. Now my question is how can one derive the apparent power equation i.e.. √...
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159 views

Why are Watt's more common than VA's?

I know that VA is the unit of apparent power (combination of real and reactive power) and Watt is the unit of real power only. So, I think it is more precise and accurate to express electrical power ...