Protection generation stations

Metal anodes using platinum and precious metal oxide coatings are also incorporated into a variety of designs of impressed current protection for pipeline and deep weU appHcations, as weU as for protection of condenser water boxes in power generating stations (see Pipelines Power generation). 

To control, regulate and protect the conversion, when necessary, from one voltage to another, in a generating station or a switchyard for the purpose of further transmission or distribution of power. 

We also provide a brief reference to a protective scheme, usually adopted in a large power-generating station as in Section 16.8.2. 

Figure 16.14 A typical protection scheme in a large generating station...

The greatest risk of contamination of a pharmaceutical product comes from its immediate environment. Additional protection from particulate and microbial contamination is therefore essential in both the filling area of the clean room and in the aseptic unit. This can be provided by a protective work station supplied with a unidirectional flow of filtered sterile air. Such a facility is known as a laminar airflow unit in which the displacement of air is either horizontal (i.e. from back to front) or vertical (i.e. from top to bottom) with a minimum homogenous airflow rate of 0.45 ms" at the working position. Thus, airborne contamination is not added to the work space and any generated by manipulations within that area is swept away by the laminar air currents. 

US-EPA (1979) Environmental impact assessment guidelines for new source fossil fueled steam electric generating stations. Environmental Protection Agency, Office of Environmental Review Springfield, VA, p 834... 

In addition, it should be demonstrated analytically that the mechanical systems can withstand a single active failure including failure of any auxiliary electric power source and not prevent delivery of sufficient cooling water to maintain the plant in a safe shutdown condition. A technique suitable for this analysis is a Failure, Modes, and Effects Analysis (FMEA). IEEE Std. 353-1975, "Guide for General Principles of Reliability Analysis of Nuclear Power Generating Station Protection Systems," provides additional guidance on the preparation of FMEAs. 

Sources of dc stray currents are commonly electric railways, grounded electric dc power lines, electric welding machines, cathodic protection systems, and electroplating plants. Sources of ac stray currents are usually grounded ac power lines or currents induced in a pipeline by parallel power lines. An example of dc stray current from an electric street railway system in which the steel rails are used for current return to the generating station is shown in Fig. 12.1. Because of poor... 

ANSI/IEEE Standard 741-1986, "Criteria for the Protection of Class IE Power Systems and Equipment in Nuclear Power Generating Stations," Institute of Electrical and Electronics Engineers, Inc. 

IEEE Standard 279-1971, "Criteria for Protection Systems for Nuclear Power Generating Stations", The Institute of Electronic and Electrical Engineers. 

IEEE Std. 741, "Protection of class IE power systems and equipment in nuclear power generating stations. ... 

Protection systems in many nuclear power plants are required to meet the design criteria of IEEE-279, "Criteria for Protection Systems for Nuclear Power Generating Stations. One of the criteria of IEEE-279 requires that. .the protection system equipment (for example, interconnecting wiring, components, modules, etc.) shall be identified distinctively as being in the protection system. This identification shall distinguish between redundant portions of the protection system. ... 

IEEE 279-1971, Criteria for protection systems for nuclear power generating stations (ANSI N42.7-1972), Institute of Electrical and Electronics Engineers. 

ANS4.1 ANS 58.1 ANS 58.2 ANS 58.5 Design basis criteria for safety system in nuclear power generating stations Plant design against missiles Design basis for protection of nuclear power plants against effects of postulated pipe rupture Probabilistic risk assessment... 

Consequently, in 1990 the Japanese Electrotechnical Research Association began a 10-year investigation of digital control circuit disturbances experienced by Japanese utilities in generator stations and substations [1]. There was a total of 330 disturbances, one-third of which were protective relays. Protective relays made up the majority of the disturbances (details of these protective relay disturbances are presented in References 2 and 3). 

In total, 330 cases of disturbances occurred in substations and generator stations over the course of 10 years, beginning in 1990 [1]. Table 6.1 classifies the disturbances by (a) troubled equipment and (b) causes. As shown in Table 6.1a, one-third of the disturbances affected protection equipment, a quarter affected telecontrol equipment, and another quarter affected control equipment. Table 6.1b shows that two-thirds of the disturbances were caused by LSs, one-sixth by SSs in the main circuits (high-voltage side), and one-twelfth by SSs in DC circuits that are part of control circuits (low-voltage side). 

Considering the aforementioned. Electro-technical Research Association in Japan had carried out investigations of disturbances of digital control circuits in generator stations and substations experienced by all the Japanese utilities for 10 years from 1990 [1]. The total number of the disturbances is 330, and one-third is for the protective relays. For protective relays show the largest number, the detail of disturbances of the protective relays is presented in [2,3]. 

DOE Order 5480.4, "Environmental Protection, Safety, and Health Protection Standards" (Reference 1), requires compliance with IEEE 308-1980, "Criteria for Class IE Power Systems for Nuclear Power Generating Stations" (Reference 2) and IEEE 603-1980, "Standard Criteria for Safety Systems for Nuclear Generating Stations" (Reference 3). Both standards require equipment qualification to be in accordance with the requirements of IEEE 323-1974,... 

Thermoelectric devices represent niche markets, but as economic and environmental conditions continue to change, they appear poised to advance into more common use. Thermoelectric power generators are in use in many areas, including sateUites, deep-space probes, remote-area weather stations, undersea navigational devices, military and remote-area communications, and cathodic protection. 

To control, regulate and protect a generator and its auxiliaries in a power station. 

Since an IPB forms an important integral part of a powergenerating station, with it are associated a number of metering and protective devices such as CTs. VTs and generator grounding system. Below we identifiy interconnections that may be required to connect these CTs and VTs while installing an IPB system. 

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