Conventional Power Generation Lecture Notes (2023-2024)

B.TECH FIRST YEAR ACADEMIC YEAR: 2023-2024 COURSE NAME: ELECTRICAL & ELECTRONICS SYSTEM (EE1002) COURSE CODE : EE 1002 LECTURE SERIES NO : 02 (ONE) CREDITS : 04 MODE OF DELIVERY : OFF LINE (POWER POINT PRESENTATION) FACULTY : EMAIL-ID :...

B.TECH FIRST YEAR ACADEMIC YEAR: 2023-2024 COURSE NAME: ELECTRICAL & ELECTRONICS SYSTEM (EE1002) COURSE CODE : EE 1002 LECTURE SERIES NO : 02 (ONE) CREDITS : 04 MODE OF DELIVERY : OFF LINE (POWER POINT PRESENTATION) FACULTY : EMAIL-ID : PROPOSED DATE OF DELIVERY: 1  “DESCRIBETHE WORKING OF SESSION OUTCOME CONVENTIONAL POWER GENERATION. ” ELECTRICAL & ELECTRONICS SYSTEM EE1002 2 ASSIGNMENT QUIZ ASSESSMENT MID TERM EXAMINATION END TERM EXAMINATION CRITERIA’S ELECTRICAL & ELECTRONICS SYSTEM EE1002 3  PROGRAM OUTCOMES MAPPING WITH CO1 [PO1] ENGINEERING KNOWLEDGE: APPLY THE KNOWLEDGE OF MATHEMATICS, SCIENCE, ENGINEERING FUNDAMENTALS, AND AN ENGINEERING SPECIALIZATION TO THE SOLUTION OF COMPLEX ENGINEERING PROBLEMS. ELECTRICAL & ELECTRONICS SYSTEM EE1002 4  CONVENTIONAL POWER GENERATION LECTURE NO. 2 ELECTRICAL & ELECTRONICS SYSTEM EE1002 5 ELECTRICAL & ELECTRONICS SYSTEM EE1002 6  CONTENTS TOPIC: 1. AC GENERATOR 2.THERMAL POWER PLANT 3. HYDEL POWER PLANT 4. NUCLEAR PLANTS ELECTRICAL & ELECTRONICS SYSTEM EE1002 7 1. AC GENERATOR  A generator has a balanced three phase winding on the stator and called the armature.  The three coils are so placed in space that there axes are mutually 120° apart as shown in Fig below. 3-phase power is obtained at armature terminals.  Rotor houses a field coil and excited by D.C. The field coil produces flux and electromagnetic poles on the rotor surface.  If the rotor is driven by an external agency, the flux linkages with three stator coils becomes sinusoidal function of time and sinusoidal voltage is induced in them.  However, the induced voltages in the three coils (or phases) will differ in phase by 120° because the present value of flux linkage with R-phase coil will take place after 120° with Y-phase coil and further 120° after, with B-phase coil. Types of AC generator Salient pole generator Non salient pole generator ELECTRICAL & ELECTRONICS SYSTEM EE1002 8 Salient pole generator Non salient pole generator Pole Shape: The rotor of a salient pole generator has poles that are wider in Pole Shape: The rotor of a non-salient pole generator has width compared to the cylindrical rotor poles of a non-salient pole generator. cylindrical poles that are of uniform width and are evenly spaced The pole faces can be somewhat round or tapered, depending on the specific design. around the rotor's circumference. This design leads to a more symmetrical rotor construction. Slower Rotation: Salient pole generators typically operate at lower speeds Higher Speeds: Non-salient pole generators can operate at compared to non-salient pole generators. This is due to the increased mass and higher speeds compared to salient pole generators due to their windage losses resulting from the larger pole faces. more balanced construction and lower windage losses. Excitation System: Due to the design of the rotor, salient pole generators Excitation System: Unlike salient pole generators, non-salient require a separate excitation system to provide direct current (DC) to the rotor pole generators often do not require a separate excitation system. winding's field windings. This excitation system controls the strength of the magnetic field produced by the rotor poles. The field windings can be supplied with DC through a variety of means, including brushes and slip rings. Construction Complexity: Constructing a salient pole generator is generally Simplicity: The construction of a non-salient pole generator is more complex compared to a non-salient pole generator due to the specialized generally simpler compared to a salient pole generator. This rotor design and the need for an excitation system. simplicity can lead to reduced manufacturing costs. Applications: Salient pole generators are often used in hydroelectric power Applications: Non-salient pole generators are commonly used in plants and other applications where the generator is subjected to varying load thermal power plants, gas turbine power plants, and other conditions. The ability to control the field current and thus the generator's voltage makes them useful in scenarios where rapid voltage regulation is applications where the generator operates under more stable and required. constant load conditions. Cost: Salient pole generators are often more expensive to manufacture due to Cost: Non-salient pole generators are often more cost-effective to the additional components required for the excitation system and the unique produce compared to salient pole generators due to their simpler rotor design. design. ELECTRICAL & ELECTRONICS SYSTEM EE1002 9  2. THERMAL POWER PLANT  In a thermal power plant coil is burnt to produce high temperature and high pressure steam in a boiler. The steam is passed through a steam turbine to produce rotational motion.  The generator, mechanically coupled to the turbine, thus rotates producing electricity.  Chemical energy stored in coal after a couple of transformations produces electrical energy at the generator terminals as shown in the figure below, Stringent conditions (such as use of more chimney heights along with the compulsory use of electrostatic precipitator) are put by regulatory authorities to see that the effects of pollution is minimized.  A large amount of ash is produced every day in a thermal plant and effective handling of the ash adds to the running cost of the plant. Fig. 1 Thermal Power Station ELECTRICAL & ELECTRONICS SYSTEM EE1002 10 3. HYDEL POWER PLANT  In a hydel power station, water head is used to drive water turbine coupled to the generator. Water head may be available in hilly region naturally in the form of water reservoir (lakes etc.) at the hill tops.  The potential energy of water can be used to drive the turbo generator set installed at the base of the hills through piping called pen stock. Fig. 2 Hydel Power Plant  Water head may also be created artificially by constructing dams on a suitable river.  In contrast to a thermal plant, hydel power plants are eco-friendly, neat and clean as no fuel is to be burnt to produce electricity.  Running cost of hydel power plants are low, the initial installation cost is rather high compared to a thermal plants due to massive civil construction necessary ELECTRICAL & ELECTRONICS SYSTEM EE1002 11 4. NUCLEAR POWER PLANT  Atomic power plants work on the principle of nuclear fission of 235U. In the natural uranium, 235U constitutes only 0.72% and remaining parts is constituted by 99.27% of 238U and only about 0.05% of 234U.  The concentration of 235U may be increased to 90% by gas diffusion process to obtain enriched 235U. When 235U is bombarded by neutrons a lot of heat energy along with additional neutrons are produced. Fig4. Nuclear Power Plant  These new neutrons further bombard 235U producing more heat and more neutrons. Thus a chain reaction sets up. However, this reaction is allowed to take place in a controlled manner inside a closed chamber called nuclear reactor.  To ensure sustainable chain reaction, moderator and control rods are used. Moderators such as heavy water (deuterium) or very pure carbon 12C are used to reduce the speed of neutrons. To control the number neutrons, control rods made of cadmium or boron steel are inserted inside the reactor.  The control rods can absorb neutrons. To decrease the number of neutrons, the control rods are lowered down further and vice versa. The heat generated inside the reactor is taken out of the chamber with the help of a coolant such as liquid sodium or some gaseous fluids. ELECTRICAL & ELECTRONICS SYSTEM EE1002 12  The coolant gives up the heat to water in heat exchanger to convert it to steam as shown in figure. The steam then drives the turbo set and the exhaust steam from the turbine is cooled and fed back to the heat exchanger with the help of water feed pump.  The initial investment required to install a nuclear power station is quite high but running cost is low. Although, nuclear plants produce electricity without causing air pollution, it remains a dormant source of radiation hazards due to leakage in the reactor. ELECTRICAL & ELECTRONICS SYSTEM EE1002 13