(SEM-VII) THEORY EXAMINATION 2018-19 POWER STATION PRACTICE

SECTION – A

(Attempt ALL parts – 2 × 10 = 20 marks)

(a) Total Power Plant Installed Capability in India

The total installed power generating capacity in India refers to the maximum electrical power that all power stations together can produce under ideal conditions. It includes thermal, hydro, nuclear, and renewable energy sources. This capacity keeps increasing with new projects to meet growing electricity demand.

(b) Load Factor and Penalty Factor

Load factor is the ratio of average load to maximum demand during a given period. It indicates how efficiently a power plant is used. Penalty factor is applied when consumers maintain a low load factor, as it increases the cost of electricity generation and distribution.

(c) Tariff and Its Types

Tariff is the rate charged to consumers for the supply of electrical energy. Common types include simple tariff, flat rate tariff, block rate tariff, two-part tariff, and power factor tariff. Tariff design aims to recover costs and encourage efficient power usage.

(d) Classification of Hydraulic Turbines

Hydraulic turbines are classified based on head, direction of flow, and specific speed. According to head, they are low-head, medium-head, and high-head turbines. Examples include Pelton, Francis, and Kaplan turbines.

(e) Functions of Moderator and Coolant in Nuclear Power Plant

The moderator slows down fast neutrons to thermal energy level to sustain nuclear fission. The coolant removes heat produced in the reactor core and transfers it to the heat exchanger for power generation.

(f) Economic Load Dispatch and Unit Commitment

Economic load dispatch determines how load is shared among operating units at minimum cost. Unit commitment decides which generating units should be ON or OFF to meet load demand efficiently while considering constraints.

(g) Causes of Low Power Factor

Low power factor is caused by inductive loads such as motors, transformers, and fluorescent lamps. Lightly loaded machines and fluctuating loads also reduce power factor.

(h) Power Output of U-235 Reactor

Power output of a nuclear reactor depends on the energy released per fission, amount of fuel used, and time. U-235 releases large energy per fission, making nuclear plants highly efficient compared to conventional plants.

(i) Advantages of Pulverised Coal

Pulverised coal improves combustion efficiency, allows better control of air-fuel ratio, increases thermal efficiency, and reduces smoke formation in thermal power plants.

(j) Generators Used in Wind Energy Generation

Wind energy systems commonly use induction generators, synchronous generators, and permanent magnet generators. These generators convert mechanical wind energy into electrical energy efficiently.

SECTION – B

(Attempt ANY THREE parts – 10 × 3 = 30 marks)

(a) Coal Consumption of Thermal Power Station

In this numerical-based question, coal consumption per hour is calculated using plant output, efficiency, calorific value of coal, and heat rate. It helps determine fuel cost and operating efficiency of the power station.

(b) Classification of Hydro-Electric Power Plants

Hydro-electric plants are classified based on water flow regulation as run-of-river, storage, and pumped storage plants. Based on head, they are low-head, medium-head, and high-head plants. Based on load, they are base-load or peak-load plants.

(c) Overall Efficiency of Thermal Power Plant

Overall efficiency is the product of boiler efficiency, turbine efficiency, and generator efficiency. It indicates how effectively fuel energy is converted into electrical energy.

(d) Power Factor Improvement Methods

Power factor is improved using shunt capacitors, synchronous condensers, and phase advancers. Improved power factor reduces losses and improves voltage regulation.

SECTION – C

(Attempt ANY ONE part from each question – 10 × 5 = 50 marks)

Q4(a) Working of Diesel Power Plant

A diesel power plant works on the principle of internal combustion. Diesel fuel is injected into compressed air, ignites due to high temperature, and produces power. The engine drives an alternator to generate electricity. Diesel plants are used for standby and peak load operation. They have high starting reliability but higher fuel cost.

Q4(b) Site Selection and Working of Nuclear Power Plant

Site selection depends on availability of cooling water, safety, waste disposal, and distance from populated areas. In a nuclear plant, heat from fission is transferred to coolant, then to steam generator, and finally used to drive a turbine. Nuclear reactors are classified as PWR, BWR, PHWR, and fast breeder reactors.

Q5(a) Two-Part Tariff Calculation

In this problem, fixed and running charges are calculated based on annual expenses, maximum demand, and energy consumption. Two-part tariff includes a demand charge (₹/kW) and an energy charge (₹/kWh). It ensures fair cost recovery from consumers.

Q5(b) Substation Layout and Busbar Arrangements

A substation layout includes transformers, circuit breakers, isolators, and busbars arranged for safe and reliable operation. Busbar arrangements such as single busbar, double busbar, and ring busbar are selected based on reliability and cost.

Q6(a) Hydrothermal Scheduling

Hydrothermal scheduling determines optimal power generation from hydro and thermal plants while satisfying load demand and system constraints. It minimizes fuel cost while considering water availability and operating limits.