Engineering

FACTS SYSTEM CONTROLLER

SVC: Uses thyristor valves to rapidly add or remove shunt connected reactors and or capacitors often in coordination with mechanically controlled reactors and/or capacitors. NGH-SSR DAMPER: a resonance damper, a thyristor ac-switch connected in series with a small inductor and resistor across the series capacitor. STATCOM (static condenser): A 3 phase inverter that is driven…

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VAR COMPENSATION

VAR compensation is defined as the management of reactive power to improve the performance of ac power systems; maximizing stability by increasing flow of active power. Few Problems forced while reactive power compensation which are:1. Load compensation 2. Voltage supportLOAD COMPENSATION OBJECTIVES: are to increase the value of the system power factor to balance the…

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WHAT IS ELECTRICAL POWER DISTRIBUTION

The electrical powers generated are either transferred onto a bus to be distributed (small scale), or into a power grid for transmission purposes (larger scale). This is done either directly or through power transformers, depending on the generated voltage and the required voltage of the bus or power grid.The next step is power transmission, whereby…

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ACTIVE FILTERS OR ACTIVE POWER LINE CONDITIONERS

The growing number of power electronics base equipment has produced an important impact on the quality of electric power supply. Both high power industrial loads and domestic loads cause harmonics in the network voltages. At the same time, much of the equipment causing the disturbances is quite sensitive to deviations from the ideal sinusoidal line…

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DIFFERENCES BETWEEN RELIABILITY AND SECURITY AND STABILITY

RELIABILITYIs the overall objective in power system design and operation. To be reliable, the power system must be secure most of the time. To be secure, the system must be stable but must also be secure against other contingencies that would not be classified as stability problems e.g., damage to equipment such as an explosive…

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BASIC INSULATION LEVELS BIL

Having decided the voltage that are required to be created at any substation it is necessary to establish a common insulation level for all items of equipment of each system voltage.It is to be ensured that the breakdown or flashover strength of all insulation (particular voltage) in the station will exceed the selected level. After…

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APPLICATIONS OF POWER ELECTRONICS

It is astonishing to realize that there is hardly a home, office block, factory, car, sports hall, hospital or theatre without an application, and sometimes many applications, of power electronic equipment. Some typical applications are given below: Industrial processes in the chemical, paper and steel industries;Domestic and theatre lighting;Motor drives from food mixers and washing machines…

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GENERATOR OVERSPEED PROTECTION

It has been noted above that over-speed causes overvoltage, which may be protected against using overvoltage relays. Basically, however, over-speed control is part of the turbine control system. Most large steam turbine controls have two or three separate speed control units, with one of these being strictly a mechanical centrifugal device that will close the…

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GENERATOR MOTORING PROTECTION

Motoring protection is provided for the steam or hydraulic turbine, or for the power system, and not for the generator. Motoring is not harmful to the generator in any way. The protection is usually considered as part of the generator protective system since it uses electrical quantities, usually in the form of sensitive power relays.Steam…

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GENERATOR VIBRATION PROTECTION

Vibration protection is also a part of the turbine protection system and is not normally supplied or specified by the electrical protection engineer. Still, as noted above, vibration detection is the backup for faults that cause unbalanced rotor heating due to rotor faults or negative-sequence rotor heating. It is important that there be coordination between…

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GENERATOR FIRE PROTECTION

Special fire protection equipment is sometimes used to quickly extinguish fires within the generator housing. One method that has been used releases water into the generator enclosure on detection of a fire. A better system injects carbon dioxide into the generator rather than water. This is safer and does not add to the damage caused…

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GENERATOR COOLANT FAILURE PROTECTION

Some of the larger generators have stator windings that are cooled by water circulating through the windings. If the flow of cooling water is impeded or stopped for some reason, the winding will quickly overheat. The cooling water is circulated by water pumps, which are backed up by standby pumps.Flow detectors placed in the water…

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OPERATION OF INDUCTION GENERATOR

Under normal operation of a synchronous generator, the field created by the rotor windings locks in with revolving mmf of the stator windings and the rotor moves at synchronous speed, at least in the steady state. When excitation is lost, the rotor field suddenly loses its mmf and the rotor begins to move away from…

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Motion Study – Human Effort Engineering

Purpose: The goal of motion study is to enhance work performance (quantity and quality¬†of output) through analysis and improvement of body and hand movements. Motion study can be thought of system improvement at a micro level [1] and is a part of human effort engineering.   In the contemporary work environment, motion study also involves…

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ADVANTAGES AND DISADVANTAGES OF STAR DELTA STARTER

ADVANTAGES OF STAR DELTA STARTER: a ) Star-Delta starters are widely used due to their relatively low price. b ) There are no limits to the number of times they can be operated. c ) The components require very little space. d ) The starting current is reduced to approximately one-third. DISADVANTAGES OF STAR DELTA…

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