tag:blogger.com,1999:blog-59715148288837056482024-02-07T06:27:00.920-08:00Hydro Power PlantsHydro power How a Hydro Power Plant works the Renewable energy source Hydro power is utilized. How a Turbine, Generator Power Transformer work in a power station.Unknownnoreply@blogger.comBlogger66125tag:blogger.com,1999:blog-5971514828883705648.post-73470259729944807782013-04-11T21:08:00.003-07:002013-04-11T21:08:46.577-07:00Switch Yard Equipment
Substation- Introduction
An electrical substation is a subsidiary station of an electricity generation, transmission and distribution system where voltage is transformed from high to low or the reverse using transformers. Electric power may flow through several substations between generating plant and consumer, and may be changed in voltage in several steps.
Circuit breaker
The circuit Unknownnoreply@blogger.comtag:blogger.com,1999:blog-5971514828883705648.post-55414146151807128352012-06-08T01:23:00.002-07:002012-06-08T01:26:24.927-07:00Cooling System of Power transformerCooling System
The cooling of transformers differs from that of rotary machinery in that there is no inherent relative rotation to assist in the circulation of ventilating air. The losses are comparatively small, and the problem of cooling can in most cases be solved by reliance on natural self-ventilation.
Simple Cooling
AN: Natural cooling by atmospheric Unknownnoreply@blogger.comtag:blogger.com,1999:blog-5971514828883705648.post-55736945787791706092011-11-06T08:18:00.000-08:002011-11-06T08:23:28.763-08:00Types of Underground transmission linesTypes of Underground transmission lines 1. High Pressure Fluid Filled pipe type (HPFF)- The conductor and its wrappings are often referred to as “cables.” The cables are surrounded by a dielectric oil that is maintained at 200 pounds per square inch (psi). This fluid acts as an insulator 2. High Pressure Gas Filled pipe type (HPGF)- Instead of a dielectric fluid, pressurized nitrogen gas Unknownnoreply@blogger.comtag:blogger.com,1999:blog-5971514828883705648.post-24001085757315182942011-10-28T20:57:00.000-07:002011-10-28T21:03:50.734-07:00Operation of Current TransformersCurrent TransformersThe primary of a current transformer typically has only one turn. This is not really a turn or wrap around the core but just a conductor or bus going through the “window.” The primary never has more than a very few turns, while the secondary may have a great many turns, depending upon how much the current must be stepped down. In most cases, the primary of a current Unknownnoreply@blogger.comtag:blogger.com,1999:blog-5971514828883705648.post-88390702387399530482011-10-26T20:59:00.000-07:002011-10-26T21:07:45.093-07:00GROUNDING SYSTEMIntroductionProper grounding system will assure the safety of people and protection of equipments at faults. In large electrical system like power house or a substation has a grounding mesh instead of a single conductor. Ground Potential Rise (GPR) The substation earth provides the connection to earth at zero potential. But at fault conditions potential of the grounding mesh rises due Unknownnoreply@blogger.comtag:blogger.com,1999:blog-5971514828883705648.post-9229469728736504952011-10-22T21:08:00.000-07:002011-10-22T21:12:50.610-07:00SUPERVISORY CONTROL AND DATA ACQUISITION SYSTEM (SCADA)Introduction to SUPERVISORY CONTROL AND DATA ACQUISITION SYSTEM (SCADA)SCADA refers to a system that collects data from various sensors at a plant or in otherremote locations and then sends this data to a central computer which then manages andcontrols the data. There are two elements in SCADA application such as the process orsystem want to monitor and Unknownnoreply@blogger.comtag:blogger.com,1999:blog-5971514828883705648.post-56138557667236503902011-10-11T05:54:00.000-07:002011-10-11T05:57:33.359-07:00PROTECTIVE RELAYSPROTECTIVE RELAYS IntroductionA protective relay is a device that detects the fault and initiates the operation of the circuitbreaker to isolate the defective element from the rest of the system. Most of the relays inservice on power system today operate on principle of electromagnetic attraction orelectromagnetic induction. Regardless of the principle involved, relays Unknownnoreply@blogger.comtag:blogger.com,1999:blog-5971514828883705648.post-5926115845839263092011-09-23T00:46:00.000-07:002011-09-23T00:47:51.894-07:00Voltage transformerVoltage transformer A voltage transformer (VT) is a transformer used in power systems to step-down extra highvoltage and provide low voltage either for measurement or to operate a protective relay. 1. Inductive Voltage Transformer (IVT) 2. Capacitor Voltage Transformer (CVT) Accuracy Class Designation Measuring Voltage Transformers The accuracy class is designated by the highest Unknownnoreply@blogger.comtag:blogger.com,1999:blog-5971514828883705648.post-72135575988823329392011-09-20T18:43:00.000-07:002011-09-20T18:45:40.431-07:00Disconnecting switch , Earthing SwitchDisconnecting switchDisconnect switches are used to isolate a component of an electrical system from the power source. Electrical power distribution systems require switching for many reasons, including fault isolation, transfer loads from one source to another, isolation of line segments for purpose of maintenance, and in some instances for shedding loads.1. Unknownnoreply@blogger.comtag:blogger.com,1999:blog-5971514828883705648.post-49916687735983483252011-09-16T19:49:00.000-07:002011-09-16T19:57:24.373-07:00Gas Circuit Breaker (GCB) - ContinueCurrent interruption in a high-voltage circuit-breaker is obtained by separating two contacts in a medium, such as SF6, having excellent dielectric and arc quenching properties. After contact separation, current is carried through an arc and is interruptedwhen this arc is cooled by a gas blast of sufficient intensity. Gas blast applied on the arc must be able toUnknownnoreply@blogger.comtag:blogger.com,1999:blog-5971514828883705648.post-62601970587216013102011-09-13T07:29:00.000-07:002011-09-13T07:42:00.100-07:00AVR Automatic Voltage RegulatorGenerator ControlAutomatic Voltage Regulator (AVR) is the main controller of the Generator.AVR has the control over the Excitation System.Voltage RegulatorThe voltage regulator are composed of automatic voltage regulator(AVR), manual voltageregulator (MEC) and over current limiter(OCL).Automatic voltage regulator (AVR)An automatic voltage control device "senses" changes in output voltageUnknownnoreply@blogger.comtag:blogger.com,1999:blog-5971514828883705648.post-64843617004693224462011-09-10T07:11:00.000-07:002011-09-10T07:15:37.407-07:00SURGE ARRESTER- Introduction<!--[if gte mso 9]> Normal 0 false false false EN-US X-NONE SI-LK MicrosoftInternetExplorer4 <![endif]--><!--[if gte mso 9]>Unknownnoreply@blogger.comtag:blogger.com,1999:blog-5971514828883705648.post-88817007254225864512011-09-05T09:20:00.000-07:002011-09-05T09:21:43.808-07:00Gas Circuit Breaker (GCB)Gas Circuit Breaker (GCB)Current interruption in a high-voltage circuit-breaker is obtained by separating two contacts in a medium, such as SF6, having excellent dielectric and arc quenching properties. After contact separation, current is carried through an arc and is interrupted when this arc is cooled by a gas blast of sufficient intensity. Gas blast applied onUnknownnoreply@blogger.comtag:blogger.com,1999:blog-5971514828883705648.post-81264856335775699842011-09-03T06:13:00.000-07:002011-09-03T06:14:33.780-07:00Circuit breaker Circuit breaker
The circuit breaker is used for switching the circuit current and short circuit current interruption. There are two types of circuit breakers used in power station.
1. Live tank type: Enclosure-Live, Breaking parts-Live
2. Dead tank type: Enclosure-Grounded, Breaking parts-Live
For arc Interruption in a circuit breaker Air, Oil, Vacuum, Gas (SF6) are used.
Unknownnoreply@blogger.comtag:blogger.com,1999:blog-5971514828883705648.post-83355515087023889832011-09-01T07:28:00.000-07:002011-09-01T07:37:37.176-07:00Substation types
Air Insulated Switchgear
An electric power substation that has the bus bars and equipment terminations generally
open to air and utilizes insulation properties of ambient air for insulation to ground.
Gas Insulated Switchgear
An electric power substation in which all live equipment and bus bars are housed in grounded metal enclosures sealed and filled with sulfurUnknownnoreply@blogger.comtag:blogger.com,1999:blog-5971514828883705648.post-8097559095639853122011-08-30T08:09:00.000-07:002011-08-30T08:12:05.371-07:00SWITCHYARD EQUIPMENT- Introduction Substation
An electrical substation is a subsidiary station of an electricity generation, transmission and distribution system where voltage is transformed from high to low or the reverse using transformers. Electric power may flow through several substations between generating plant and consumer, and may be changed in voltage in several steps. Unknownnoreply@blogger.comtag:blogger.com,1999:blog-5971514828883705648.post-29967523789492339952011-07-21T00:15:00.000-07:002011-07-21T00:16:34.971-07:00Conservator System<!--[if gte mso 9]> Normal 0 false false false EN-US X-NONE SI-LK <![endif]--><!--[if gte mso 9]>Unknownnoreply@blogger.comtag:blogger.com,1999:blog-5971514828883705648.post-76630509111876236652011-07-21T00:14:00.000-07:002011-07-21T04:50:53.208-07:00Main components of a power transformer<!--[if gte mso 9]> Normal 0 false false false EN-US X-NONE SI-LK <![endif]--><!--[if gte mso 9]>Unknownnoreply@blogger.comtag:blogger.com,1999:blog-5971514828883705648.post-14943023842671767412011-07-21T00:10:00.001-07:002012-03-30T02:29:11.613-07:00Shell Type and Core Type TransformersMain Types of TransformersUnknownnoreply@blogger.comtag:blogger.com,1999:blog-5971514828883705648.post-55849321098112885482011-07-21T00:08:00.000-07:002011-07-21T00:10:24.400-07:00Additional Construction Features of a Power Transformer,Carbon Dioxide (CO2) Fire Fighting System CO2 fire fighting system Fire extinguishing system for two main transformers and two generators The fire extinguisher is commonly be used for two sets of main transformers and two sets of generators and detect fire inside the transformer room and generator housing instantaneously and accurately, and automatically discharge carbon Unknownnoreply@blogger.comtag:blogger.com,1999:blog-5971514828883705648.post-9989348012655582002011-07-21T00:07:00.001-07:002011-07-21T00:07:59.321-07:00Power Transformer- Cooling Methods- Internal CoolingInternal Cooling The heating of the coils depends on their thermal conductivity, which is itself a function of • Thickness of the winding • External insulation A coil design, which allows the copper heat to flow radially outwards with little cross insulation in the path of the flow, leads to economical rating in that a high current density can be employed for a given temperature Unknownnoreply@blogger.comtag:blogger.com,1999:blog-5971514828883705648.post-85423477368377914442011-07-21T00:06:00.000-07:002011-07-21T00:07:20.426-07:00Power Transformer- Cooling Methods-Forced Oil CoolingForced Oil Cooling When forced cooling becomes necessary in large high-voltage oil-immersed transformers. The choice of the method of cooling will depend largely upon the conditions obtaining at the site. Air-blast cooling can be used, a hollow-wailed tank being provided for the transformer and oil, the cooling air being blown through the hollow space. The heat Unknownnoreply@blogger.comtag:blogger.com,1999:blog-5971514828883705648.post-32159560412750320292011-07-21T00:05:00.000-07:002011-07-21T00:06:15.377-07:00Power Transformer- Cooling Methods-Natural Oil CoolingNatural Oil Cooling The oil in the ducts, and at the surface of the coils and cores, takes tip heat by conduction, and raises cool oil from the bottom of the tank rising to take its place. A continuous circulation of oil is completed by the heated oil flowing to the tank sides where cooling to the ambient air occurs and falling again to the bottom of the tank. Oil Unknownnoreply@blogger.comtag:blogger.com,1999:blog-5971514828883705648.post-51054606280972228662011-07-21T00:04:00.000-07:002011-07-21T00:05:32.390-07:00Power Transformer- Cooling Methods -Mixed CoolingMixed Cooling ON/OB: As ON, but with alternative additional air-blast cooling. ON/OFN, ON/OFB, ON/OFW, ON/OB/OFB, ON/OW/OFW: Alternative cooling conditions in accordance with the methods indicated. A transformer may have two or three ratings when more than one method of cooling is provided.Unknownnoreply@blogger.comtag:blogger.com,1999:blog-5971514828883705648.post-44286337323985108372011-07-21T00:02:00.000-07:002011-07-21T00:04:45.746-07:00Power Transformer- Cooling MethodsSimple Cooling AN: Natural cooling by atmospheric circulation, without any special devices. The transformer core and coils are open all round to the air. This method is confined to very small units at a few kV at low voltages. AB: The cooling is improved by an air blast, directed by trunking and produced by a fan. OB: The cooling of an ON-type is improved by air blast over the Unknownnoreply@blogger.com