WorksheetsQUIZ 2
Total questions: 18
Worksheet time: 36mins
For the economic operation, the generator at a power plant operates at ____ Also specify that the penalty factor is the measure of____
Equal loads; line loss
Equal power rating; generation cost
Equal loads; fuel cost
Equal incremental cost; line loss
Calculate the power loss, if power generated by two plants are P1=50 MW and P2=40 MW and the loss coefficients are B11=0.001, B22=0.0025 and B12=-0.0005.
4.5 MW
5.5 MW
6.5 MW
8.5 MW
The incremental fuel cost of two generating units are given by IC1=10+0.2 PG1 IC2=16+0.2 PG2 Where PG1 and PG2 are real power generated by the units. Find the economic allocation for a total load of 170 MW. (neglect transmission line losses)
PG1=60 MW, PG2=110 MW
PG1=80 MW, PG2=90 MW
PG1=100 MW, PG2=70 MW
PG1=120 MW, PG2=50 MW
The economical operation of power system, the effect of increased penalty factor between generating plant and system load current is to
decrease the load on the generating plant
increase load on the plant
hold the plant load constant
increase the power factor
The fuel cost functions in rupees/hour for two 600 MW thermal power plants are given by Plant 1: C1=350+6P1+0.004(P1)2 Plant 2: C2=450+aP2+0.003(P2)2 where P1 and P2 are power generated by plant 1 and plant 2, respectively, in MW and a is constant. The incremental cost of power ( λ ) is 8 rupees per MWh. The two thermal power plants together meet the total power demand of 550 MW.
200, 350
250, 300
325, 225
350, 200
The incremental cost characteristics of two generators delivering a total load of 230 MW are as follows: IC1=2.4+0.01P1 IC2=2+0.02P2. The ratio of P1/P2 is:
0.6429
2
1
1.55
Unit commitment in power systems primarily deals with
Determining generator voltage levels
Scheduling which generating units will be ON/OFF
Real-time frequency regulation
Reserving fuel for generators
Which of the following constraints is NOT part of unit commitment?
Minimum up-time
Minimum down-time
Ramp rate limits
Per-unit conversion
In thermal plants, minimum up-time constraint means
A unit must remain OFF for a fixed duration
A unit must remain ON for a fixed duration once started
A unit cannot exceed maximum power
A unit must maintain constant frequency.
Which method of load flow analysis is most commonly used in practical power systems?
Gauss–Seidel method
Newton–Raphson method
Fast Decoupled Load Flow
None of the above
The Fast Decoupled Load Flow (FDLF) method assumes
Voltage magnitudes vary greatly
R/X ratio is very high
P–δ and Q–|V| are weakly coupled
No reactive power variation
Which of the following is NOT an advantage of Newton–Raphson method?
Fast convergence
Good for large systems
Low memory requirements
Robustness
Line flows are computed after load flow solution using
Z-bus matrix
Y-bus matrix
Jacobian matrix
Newton coefficients
A single-machine infinite bus (SMIB) system assumes
Both machine and grid have finite inertia
Infinite bus has constant voltage and frequency
No mechanical power input
No electrical power output
The swing equation represents
Voltage dynamics
Rotor angle dynamics of a synchronous machine
Load variations
Transformer flux balance
For a system with n buses, the Z-bus order is
n × n
(n-1) × (n-1)
n × (n-1)
2n × 2n
The diagonal element of Z-bus represents
Line admittance
Self-impedance of that bus
Generator reactance
Shunt capacitance
Z-bus building algorithm is based on
Gauss elimination
Gauss–Seidel iteration
Adding elements using bus building approach
Newton method
