Power Transmission and Conductors Review

These flashcards cover key concepts from power transmission and conductor technology, including definitions, principles, and notable facts necessary for exam preparation.

What units do the ABCD parameters have?

pu, ohms, s, pu

Can voltage regulation be negative?

Yes, if the voltage at full load is greater than at no load.

Is the equivalent π circuit identical in structure to the nominal π circuit?

True

What is Surge Impedance Loading (SIL)?

The power delivered by a lossless line to a load resistance equal to Zc.

At Surge Impedance Loading, what is the voltage profile and real power delivered?

Flat voltage profile; real power is given by (V^2)/(Zc).

Is it true that the maximum power flow for a lossy line is less than for a lossless line?

True

Are high-voltage transmission lines effective for transmitting reactive power over long distances?

False, they have higher losses.

Can a synchronous machine generate reactive power without producing real power?

Yes, by operating at a zero power factor.

In point-to-point bulk power transmission, from where does real power flow?

From the bus with a higher phase angle to a lower phase angle.

In point-to-point power transmission, where does reactive power flow?

From the bus with a higher voltage magnitude to a lower.

Why are transmission line conductors typically made of aluminum?

Due to lower cost and lighter weight.

What are the three major line-loading limits for long transmission lines, in order?

Steady-state stability limit, voltage drop, thermal limit.

What does SIL refer to in transmission lines?

The optimal loading level where reactive power generated by line capacitance equals inductive reactance.

What type of conductor construction is typical for transmission lines?

Stranded construction.

What is the corona effect?

When the electric field becomes ionized.

At which voltage is corona effect more likely: 115 kV or 765 kV?

765 kV.

What does ACSR stand for?

Aluminum Conductor Steel Reinforced.

What factors affect the conductor's resistance?

Temperature, magnitude of the metal, length.

What is the most commonly used metal for overhead transmission conductors?

Aluminum.

What happens to voltage regulation with lagging power factor?

Vrnl > Vrfl resulting in higher voltage regulation.

What are the steady-state stability limits of transmission lines?

Voltage drop limit of 5% between sending and receiving ends.

What do shunt reactors and capacitors do in transmission systems?

Shunt reactors absorb reactive power; capacitors deliver reactive power.

What is the purpose of reactive compensation techniques?

To increase line loadability and the steady-state limit.

Who invented the three-phase generator?

Mikhail Dolivo-Dobrovolsky.

What is the frequency of power generation in the US and Europe?

US: 60 Hz; EU: 50 Hz.

What happens during a three-phase fault regarding voltage?

Voltage does not collapse to 0 with an infinite bus.

What is the ERCOT infinite bus size?

100 GW.

What is the load capacity of Texas?

85 GW.

Who are some manufacturers of conductors and transformers?

Conductors: ALCOA; Transformers: GE, Siemens.