Transient Analysis of Electric Power Circuits Handbook by Arieh L. Shenkman | 9780387287973 | 387287973

Electric Power

Transient Analysis of Electric Power Circuits Handbook

118 SOLVED PROBLEMS

Question: III

Find the short-circuit current at the fault point F using the linearization approach for two cases: a) the AVRs are not activated; b) the AVRs are activated. ...

Verified Answer:

The one-line diagram of the network is shown in Fi...

Question: 8.5

Examine the voltage stability of a non-static load supplied from a 275 kV infinite bus bar through a line of reactance 50 Ω per phase. The load consists of a constant active power of 200 MW and 200 MVAr rating reactive power, which is related to the voltage by the equation (in pu) ...

Verified Answer:

With

S_b = 200 MVA and V_b = 275 kV[/...

Question: 8.4

Apply the equal-area criterion to the system of Example 8.3. ...

Verified Answer:

We may calculate the critical clearing angle as fo...

Question: 8.3

Assume that, at the sending-end of one of the transmission lines in the system shown in Fig. 8.7, a three-phase fault occurs. Develop and solve the swing equation of the system, if the fault reactance is 0.07 pu. The inertia constant of the generator is H = 0.5 s and the frequency f = 60 Hz. ...

Verified Answer:

The power-angle characteristic prior to the fault ...

Question: 8.2

A synchronous generator of reactance 1.25 pu is connected to an infinite bus bar system of V =1 pu through a line and transformers of a total reactance of 0.5 pu. The generator’s inertia constant is H = 5 s and EMF is 2.5 pu, and it operates at a load angle of 47°. Find the expression of the ...

Verified Answer:

The transmitted power of the generator is

P...

Question: 8.1

A synchronous generator having a local load, represented by constant impedance, is connected to an infinite bus through a transformer and a double circuit transmission line. The direct axis generator synchronous reactance is 1.2 pu, the load impedance is Zload = 2 ∠ 36° pu and the rest of the ...

Verified Answer:

First we find the angle of the generator terminal ...

Question: 7.6

An underground cable (‘‘very long’’) has distributed parameters R = 1 Ω/km and C = 0.1 μF/km. Assuming that at time t = 0 a step voltage source υs = 500u(t) V connects to the cable, find the voltage and current distribution along the cable line at t1 = 10 μs and at t1 = 50 μs. ...

Verified Answer:

The parameters of the cable are

a=1/\sqrt{C...

Question: 7.5

Consider an underground cable line 1.6 km long with a characteristic impedance of 50 Ω and a wave propagation velocity of 1.6·10^8 m/s. The line is connected to the d.c. ideal Zs = 0 voltage source V0 = 1000 V and terminated in a 200 Ω resistor. (a) Determine the reflection coefficients at the ...

Verified Answer:

(a) The reflection coefficients are

\rho _...

Question: 7.4

The characteristic impedances of an overhead line and underground cable connected in series (Fig. 7.15(a)) are 400 Ω and 50 Ω respectively. The incident surge voltage of 800 kV rms is traveling on the overhead line toward the junction. Determine: (a) the surge voltage transmitted into the cable; ...

Verified Answer:

(a)

\upsilon _{f2}=\rho _{ref}\upsilon...

Question: 7.3

A line has a characteristic impedance of 400 Ω and a terminating resistance of 600 Ω. Assuming that the incident voltage wave is 100 kV, determine the following: (a) The reflection coefficient of the voltage wave; (b) The reflection coefficient of the current wave; (c) The backward-traveling ...

Verified Answer:

(a)

\rho_{rV}=\frac{R_T−Z_c}{R_T+Z_c} =\f...