Electrical power systems utility services

Power System Station Services The other major system of a nuclear plant is the electric power system. The normal electric power system comprises a main power output transformer, unit and service transformers, and a switchyard. This system steps up (increases) the generator output voltage to match the electric utility s grid requirements for... 

Power system planners need to consider how the costs associated with electric vehicles should he passed along to consumers. Fortunately from a load balancing perspective, it is likely that most EV charging will occur in off-peak periods. Charging in off-peak periods would reduce utility costs and therefore should allow utilities to reduce customer rates, but this would require time of day metering that is not available in most service areas. 

The power demand of electrolysers and power outputs of oxy-hydrogen turbines can be changed very rapidly compared to traditional peak-electricity production technologies. Consequently, these systems can be used for power regulation to produce higher quality electricity (constant voltage and frequency). This is a very high value utility service. 

A pharmaceutical plant can obtain emergency or standby electrical power from generators, rechargeable batteries, and in rare cases from a separate utility service. Uninterruptible power supplies, central storage battery system, and unit equipment all use rechargeable batteries for their emergency source of power. 

To ensure the continuity of AC power, many commercial/industrial facilities depend on either two separate utility services or one utihty service plus on-site generation. Because of the growing complexity of electrical systems, attention must be given to power-supply rehabihty. 

For example, a motor requiring 5 kW from the line is connected to the utility service entrance. If it has a power factor of 86%, the apparent power demanded by the load will be 5 kW divided by 86%, or more than 5.8 kW. The true power is 5 kW, and the apparent power is 5.8 kW. The same amount of work is being done by the motor, but the closer the power factor is to unity, the more efficient the system. To expand on this example, for a single-phase electric motor the actual power is the sum of several components, namely... 

The larger a plant is, the more important is its electric distribution system. It must be capable of meeting the needs of all electric equipment, from the point of entrance of the power company s service (or the plant generating powerhouse) to the terminals of the utilization equipment. If electric power is not available when and where needed, the owner s investment in both plant and inventory becomes idled. 

From point of service to point of use, electric power is directed, protected, and modified by segments of the system whose function, performance, and efficiency are vital to the utilizing equipment. To operate and maintain an industrial electric distribution system properly and to understand system planning fully, it is necessary to comprehend the function of each system component and its place in the overall system. Continued reference to Fig. 5.147, the one-line diagram, will aid in putting the various elements of the system into proper perspective. 

Compact high-pressure water electrolyscrs have been utilized to produce oxygen on board nuclear-powered submarines as part of the life-support system the hydrogen by-product, while flammable, is non-toxic and easily handled. Moreover, water and electrical power are the only utilities required. Since 1966, over I million running hours have been accumulated in service by such high-pressure electrolysers (Fig. 5.6(a)). 

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