Question 1

Q.1. (a) Explain the factors effecting economic generations and distributions…

Accepted Answer

Economic generation and distribution is influenced by factors including fuel cost and availability, plant efficiency/heat rate, transmission losses, load factor and diversity factor, and capital versus operating cost trade-offs; power plant cost analysis breaks down total cost into fixed (capital, depreciation) and operating (fuel, maintenance, labor) components, influenced by plant location, size, fuel type, and load factor.

Question 2

Q.1. (a) Describe the selection methodology for thermal types of generation a…

Accepted Answer

The selection methodology for thermal generation considers factors such as fuel availability, load duty requirement, environmental constraints, and site conditions, with equipment including boilers, turbines, condensers, and cooling systems selected to match the plant's intended duty; economics of power generation and cost of electrical energy involves analyzing the levelized cost of energy across capital, fuel, and O&M components to determine the most economical generation option and set appropriate consumer tariffs.

Question 3

Q.2. (a) For Economical Operations of Thermal Power Plants explain the Method…

Accepted Answer

Economical operation of thermal power plants is achieved through appropriate methods of loading turbo generators - base loading, economic loading based on incremental heat rate, and unit commitment scheduling - while input-output and heat rate characteristic curves graphically represent a plant's fuel consumption versus output relationship, forming the basis for economic dispatch calculations.

Question 4

Q.2. (a) For a simple two unit system the loss coefficients are: B11=0.001 MW…

Accepted Answer

For the given two-unit system with loss coefficients B11=0.001, B12=-0.0005, B22=0.0024 MW^-1 and incremental costs dC1/dP1=0.08P1+16, dC2/dP2=0.08P2+12 Rs/MW-hr, solving the loss-coordinated economic dispatch equations at lambda=20 gives P1≈41.70 MW and P2≈50.19 MW, with transmission loss≈5.69 MW and received (delivered) power≈86.20 MW.

Question 5

Q.3. (A) Explain the phenomena of cogeneration, with help of a neat and label…

Accepted Answer

Cogeneration is the combined production of two useful energy forms (typically electricity and process heat) from a single fuel source, improving overall energy utilization efficiency; hydro-thermal cogeneration/coordination combines the operational flexibility of hydro plants with the steady baseload capability of thermal plants for improved overall system economy, offering advantages of improved efficiency and reduced fuel cost but requiring careful coordination and facing disadvantages including site-specific hydro constraints and coordination complexity; short-term hydro-thermal coordination optimally schedules hydro and thermal generation over a short time horizon (daily/weekly) to minimize thermal fuel cost subject to hydro energy/water availability constraints.

Question 6

Q.3. (A) For Hydro thermal cogeneration explain base load peak load operation…

Accepted Answer

In hydro-thermal cogeneration, hydro plants (particularly those with limited storage) are typically used for peak-load operation given their fast response and low operating cost, while thermal plants are used for steady base-load operation; run-off-river hydro plants (with little or no storage, generating whenever water flows) are combined with steam thermal plants such that the run-off-river plant supplies base load whenever sufficient flow is available, with thermal and/or reservoir hydro plants supplementing to meet the remaining load and peak demand.

Question 7

Q.4. (A) Explain Parallel Operations of Generators. [8]

Accepted Answer

Parallel operation of generators requires matching voltage magnitude, frequency, phase sequence, and phase angle before synchronization, after which the generators share load according to their governor droop and excitation characteristics; an infinite bus bar is an idealized bus of fixed voltage and frequency unaffected by any connected generator's output, providing the reference against which active power (controlled by prime-mover input/governor setting) and reactive power (controlled by field excitation) are independently adjusted during and after synchronization.

Question 8

Q.4. (A) During the parallel operation of generator explain effect of change …

Accepted Answer

During parallel operation, changing a generator's excitation primarily affects its reactive power output (and power factor) without significantly changing its active power/real load share, while changing its prime-mover input (governor setting) primarily affects its active power/load-current sharing; a cylindrical (round) rotor alternator, used for high-speed turbo-generators, exhibits a smooth, uniform air gap giving nearly sinusoidal, low-harmonic-content voltage waveform and a simpler (single-reactance, non-salient-pole) power-angle characteristic compared to a salient-pole machine.

Question 9

Q.5. With reference to Economics for Electrical Engineers explain the concept…

Accepted Answer

Physical efficiency measures the ratio of useful physical output to physical input for electrical goods/services (such as energy conversion efficiency of generating equipment), while financial (economic) efficiency measures the ratio of value/benefit obtained to the monetary cost incurred, and both concepts interact with market supply and demand, since improvements in physical efficiency generally reduce production cost and hence supply price, expanding quantity demanded, while financial efficiency considerations directly determine whether a given technically-efficient option is also the economically preferred choice.

Question 10

Q.5. Write short note on: (a) min cost analysis [8] (b) linear and nonlinear …

Accepted Answer

Minimum cost analysis is a technique for identifying the option among several alternatives that achieves a specified objective at the lowest total cost, particularly useful when different options have differing cost structures across capital and operating cost components; linear break-even analysis identifies the output level at which total revenue exactly equals total cost assuming constant unit price and constant unit variable cost, while nonlinear break-even analysis extends this to situations where price or cost per unit varies with output level, requiring a more general graphical or calculus-based solution approach.

Economic Operation of Power System