Protection diesel generators

Captive (emergency) power generation covers the application of a diesel generating set, its starting, protection, synchronizing and load sharing. This forms an important part of power distribution at any installation to provide a standby source of supply,... 

EGSG Idaho s Idaho National Engineering Laboratory reviewed Licensee Event Reports (LERs), both qualitatively and quantitatively, to extract reliability information in support of the USNRC s effort to gather and analyze component failure data for U.S. commercial nuclear power plants. LERs describing failures or command faults (failure due to lack of needed input) for selected components have been analyzed in this program. Separate reports have been issued for batteries and battery chargers, control rods and drive mechanisms, diesel generators, ISC, Inverters, primary containment penetrations, protective relays and circuit breakers, pumps, and valves. 

The bank needed to maximize the availability of its computer system to protect existing clients while attracting new ones. A traditional system, combining an uninterruptible power supply (ups) with power from the electric grid and backup diesel generators, would have more than a 63 percent probability of a major failure over its 20-year life. The SurePower system has less than a 1 percent chance of a major failure in 20 years. This may well be the difference between business success or bankruptcy. 

To ensure effective cathodic protection (CP) of gas pipelines in the remote arctic regions of Russia shown in Fig.l, where it would be uneconomic to run power lines and where conventional techniques such as small gas or diesel generators, wind and solar power plants fail, it is possible to use thermoelectric converters of heat into electricity and based on them standalone thermoelectric generators (TEG). 

The non-safety-related Standby ac Power Supply consists of two diesel generators. Each diesel generator (DG) provides 6.9 kVac power to one of the two load groups whenever the main turbine generator and the normal preferred off-site power source are not operating. When operating, the standby ac power supply provides power to safety- related loads and to non-safety-related investment protection loads. Other non-safety-related loads are not powered from the standby power source. 

ELECTRIC POWER SYSTEM Clas I,II and III Electnc System CSAB290 5 The Class III system pow ers designated safety -related and economic equipm i protection loads pump motors, valv es etc) Normally Class IV power supplies the Class III power W. cn the Class IV system fails two redundant standby diesel generators provide Class ni power The ac Class II and dc Class I systems supply un-mtermptible power to the control and safety svstems... 

Compared with present-day LWR plants, the electric power supply systems of PIUS have been simplified significantly. The main reason for that is obviously the "inherent" self-protective functions of PIUS that eliminate many traditional safety-grade systems or reduce their importance to such extent that they can be declassified. Thus, a "two trmn" electrical supply system structure has been found fully acceptable with respect to safety and plant availability concerns. In order to improve the reliability of the power supply for important process functions, e.g. for protection of the capital investment, low voltage diesel generators are provided in the PIUS plant, but they are not safety-grade. The elimination of most of the DC distributions represents another major simplification of the electrical power supply system. 

Loss of offsite power Reactor protection system functions Diesel generator system functions... 

In various plants, O rings leaking oil impaired the function of shock absorbers, or snubbers, that protect pipes and other equipment in the event of earthquakes. O ring problems were also found to affect diesel generators used for backup power in emergencies. 

Backup of the makeup pumps by diesel generators, and modifications of the protection logic of some makeup valves to not close them in case of containment isolation,... 

For PWRs, practically, two systems of diesel generators are provided as emergency on-site power systems in addition to the external power system which is firmly connected to the power distribution grid. Therefore, a change of loss of power source is considered extremely limited even for a short duration. Even if total loss of power sources occurs for a short duration, the reactor could be brought to a safe shutdown through actuation of the safety protection systems and the control rod clusters. 

The AP1000 PMS and passive safeguards systems are not dependent on offsite power or on any backup diesel generators. Following a loss of ac power, the protection and safety monitoring system and passive safeguards are able to perform the safety fimctions and there are no additional time delays for these functions to be completed. 

The diesel generator fuel oil transfer system consists of two independent fuel storage, transfer and recirculation flow paths that is, one path per diesel generator. Each path consists of a fuel oil storage tank, one fuel transfer pump, diesel fuel oil supply and fuel return piping, a day tank, and the associated specialties valves, fittings, and instrumentation. The supply lines from the transfer pumps to the day tanks include fuel oil heaters, filters and moisture separators. The system is protected from the effects of low temperatures by the inline electric oil heater in the transfer line. 

The spare power supply system (level B) provides supply to components performing non-safety classified functions which are needed after LOSSP with regard to investment protection. It is backed by one diesel generator and 3 batteiies. 

In inaccessible regions where an impressed current installation is not sufficiently close to a low voltage supply, the protection current can be supplied from batteries, thermogenerators, and if there is sufficient radiation from the sun, solar cells. Wind generators and diesel units, on the other hand, are less suitable because of the maintenance necessary for continuous operation. 

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