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Today each unique vendor of protection systems or major Protective Relay Manufactures has their own software for transmitting parameters and setting protective relays. This is almost always based on MicrosoftTM operating systems. It is in this element where the largest numbers of setting errors occur, this being the human element. Even with in the same manufacturing company different departments go...
Arc-flash detection sensors provide a cost-effective way to reduce arc-flash energy by minimizing detection times. High-speed light detection and tripping can compromise protection security by misoperating during changing light conditions. Trip circuits using arc-flash light detection should be supervised using overcurrent protection with similar fast detection speeds. Combining arc-flash detection...
Cradled in Virginia's rugged Allegheny Mountains, the Bath County pumped storage station, which went into operation in 1985, is jointly owned by Dominion and the operating companies of the Allegheny Power System, and managed by Dominion generation. The facility, which includes six rotating machines, each operating as a synchronous generator or synchronous motor, quietly balances the power demands...
Modern microprocessor based relays are designed to provide high speed protection under different power system conditions and configuration. Requirements for reduction in the duration of short circuit faults on transmission lines are based on significant system congestion and increased numbers of customers with loads sensitive to voltage variations. High-speed fault clearing for different faults on...
Selection of the DG interconnection protective relay is based on several criteria such as power system characteristics, the dynamic response of the generator, the system grounding, the DG transformer connection, etc., as well as the protection policy of the utility and coordination requirements. The interconnection protection IED design can be summarized as follows: disconnection of DG plants when...
High impedance bus differential relays are used on most of the busses in North America. The popularity can be explained by the good performance of this scheme in relation to CT saturation and the low cost, if used on a simple bus system. However with the introduction of numerical relays and their low CT burden as well as their ability of measuring several feeder currents, a low impedance bus differential...
The electric power system maintains a dynamic and delicate balance between generation and load in normal operatio condition. A disturbance, such as a sudden change of load, a power system fault, or a trip of a large generation unit, may break the balance, cause the oscillations among the generator rotor angles and force the generators to adjust to a new operating condition. The adjustment will not...
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