December 2014

Thermal generating plants are designed and constructed to convert energy from fuel (coal, oil, gas, or radiation) into electric power. The actual conversion is accomplished by a turbine-driven generator. Thermal generating plants differ from industrial plants in that the nature of the product never changes. The plant will always produce electric energy. The things that […]

SELECTION OF AUXILIARY SYSTEM VOLTAGES The most common plant auxiliary system voltages are 13,800 V, 6900 V, 4160 V, 2400 V, and 480 V. The highest voltage is determined by the largest motor. If motors of 4000 hp or larger are required, one should consider using 13,800 V. If the largest motor required is less

HIGH VOLTAGE CIRCUIT BREAKERS High voltage circuit breakers of 34.5 kV and above may be used in the switch-yard associated with the generating plant, but are rarely used in a generating plant. MEDIUM VOLTAGE SWITCHGEAR Medium voltage breakers are 2.4 to 13.8 kV. Breakers in this range are used for large motors in the plant.

Many motors are required in a thermal generating plant and range in size from fractional horsepower to several thousand horsepower. These motors may be supplied with the equipment they drive or they may be specified by the electrical engineer and purchased separately. The small motors are usually supplied by the equipment supplier and the large

All electrical studies should be well-documented for use in plant modifications. These studies will be of great value in evaluating plant problems. LOAD FLOW A load flow study should be performed as early in the design as possible even if the exact equipment is not known. The load flow study will help in getting an

1) EXCITERS AND EXCITATION EQUIPMENT The excitation system will normally be supplied with the generator. ELECTRONIC EXCITERS: Modern excitation systems are solid state and, in recent years, most have digital control systems. 2) GENERATOR NEUTRAL GROUNDING The generator neutral is never connected directly to ground. The method used to limit the phase to ground fault

SQUIRREL CAGE INDUCTION MOTORS The squirrel cage induction motor is the most common type of large motor used in a thermal generating plant. Squirrel cage induction motors are very rugged and require very little maintenance. WOUND ROTOR INDUCTION MOTORS The wound rotor induction motor has a rotor winding which is brought out of the motor

Energy is the capacity to do work. Energy comes in various forms, such as motion, heat, light, electrical, chemical, nuclear energy, and gravitational. Total energy is the sum of all forms of the energy a system possesses. In the absence of magnetic, electrical and surface tension effects, the total energy of a system consists of

HIGH GRADE ENERGY Electrical and chemical energy are high-grade energy, because the energy is concentrated in a small space. Even a small amount of electrical and chemical energy can do a great amount of work. The molecules or particles that store these forms of energy are highly ordered and compact and thus considered as high

Energy can be stored in many forms. Chemical potential energy is stored in fuels such as coal, wood, and food, or in the chemicals in batteries and fuel cells. Phosphorescent materials store some of the energy they absorb from visible light. After a time delay, they convert this energy back into visible light. Often energy