MCQs of Reactive Power and Voltage Control (Power System Operation and Control - 2180909)

Power System Operation and Control (2180909) MCQs

MCQs of Reactive Power and Voltage Control

Showing 1 to 10 out of 40 Questions

Voltage regulation is define as

(a)	The per unit change in the sending end voltage magnitude for a specific variation in the receiving end voltage from no load to full load
(b)	The per unit change in the receiving end voltage magnitude for a specific variation in the sending end voltage from no load to full load
(c)	The per unit change in the sending end voltage magnitude for a specific variation in the receiving end voltage
(d)	None of above

The change in real power P produces little effect on receiving end voltage because

(a)	The voltage drop associated with this change is in phase with reference voltage
(b)	The voltage drop associated with this change is in quadrature with reference voltage
(c)	The voltage drop associated with this change has no relation with reference voltage
(d)	The voltage drop associated with this change is 180 degree with reference voltage

The change in reactive power Q produces large effect on receiving end voltage because

(a)	The voltage drop associated with this change is in phase with reference voltage
(b)	The voltage drop associated with this change is in quadrature with reference voltage
(c)	The voltage drop associated with this change has no relation with reference voltage
(d)	None of above

The relation between the receiving end voltage and the reactive power in terms of short circuit strength is

(a)	$E (1 + \frac{Q}{S_{s c}})$
(b)	$E (1 - \frac{Q}{S_{s c}})$
(c)	$E (1 + \frac{2 Q}{S_{s c}})$
(d)	$(\frac{E Q}{S_{s c}})$

An inductive load draws power (2+j1) MVA at the receiving end bus of a radial three phase line. The receiving end bus voltage is 11kV (L-L) at 50 Hz. The system reactance is 0.5 Ω/phase then the regulation is

(a)	100.01 $∠$ 70.01
(b)	58.68 $∠$ 63.43
(c)	45.68 $∠$ 50.43
(d)	25.04 $∠$ 63.50

If the phase voltage is 11.46 kV and system reactance is 0.5 Ω/phase then the short circuit capacity of the system is

(a)	90.34 MVA/phase
(b)	60.34 MVA/phase
(c)	81.34 MVA/phase
(d)	None of above

If system reactive power is 1 MVAR and short circuit capacity is 81.34 MVA/phase then the ratio of receiving end to sending end voltage is

(a)	0.99
(b)	0.88
(c)	0.89
(d)	0.90

The surge impedance of transmission line is represented by (

l

is line series inductance per length,

c

is distributed capacitance per length)

(a)	$2 \sqrt{\frac{l}{c}}$
(b)	$\sqrt{\frac{l}{2 c}}$
(c)	$\sqrt{\frac{2 l}{c}}$
(d)	$\sqrt{\frac{l}{c}}$

Surge impedance loading is represented by (if V is voltage in kV and Z₀ is surge impedance loading)

(a)	$(\frac{2 V^{2}}{Z_{0}})$ MVA
(b)	$(\frac{V^{2}}{Z_{0}})$ MVA
(c)	$(\frac{V^{2}}{2 Z_{0}})$
(d)	None of above

10.

A three phase, 50 Hz transmission line operates at 220 kV. The line has 400 Ω surge impedance. Find the surge impedance loading

(a)	100 MVA
(b)	125 MVA
(c)	121 MVA
(d)	200 MVA

Showing 1 to 10 out of 40 Questions