IEEE Std 387-2017 pdf free download – IEEE Standard for Criteria for Diesel Generator Units Applied as Standby Power Supplies for Nuclear Power Generating Stations.
4.5 Design features
4.5.1 Mechanical and electrical design features
4.5.1.1 Vibration
Vibration amplitudes shall be limited to be within the design capabilities of the diesel-generator unit and auxiliary components. Solenoids, relays, and other devices shall be mounted in such a way as to reduce vibration efects.
4.5.1.2 Torsional vibration
Harmful torsional vibration stresses shall not occur within a range from 10% above to 10% below rated idle speed and from 5% above to 5% below rated synchronous speed.
4.5.1.3 Overspeed
Moving parts shall be designed to withstand that level of overspeed that results from a short-time rating load rejection. Margin shall be provided to allow the overspeed device to be set sufciently high so that the unit will not trip on short-time rating load rejection. As a minimum, the generator rotor, exciter rotor (if used), and fywheel shall be designed to withstand an overspeed of 25% without damage.
4.5.1.4 Governor operation
If the diesel engine is equipped with both isochronous (non-paralleled) and the droop (paralleled) mode, the diesel engine shall operate in both the isochronous and the droop mode. Provisions shall be included to automatically place the engine governor in the proper mode of operation when the diesel-generator unit is required to operate automatically (see 4.5.2.2). The diesel engine shall be placed in isochronous (emergency) mode when in standby.
4.5.1.5 Voltage regulator operation
If the diesel engine is equipped with both isochronous (non-paralleled) and the droop (paralleled) mode, the voltage regulator shall operate in the isochronous and the droop and droop mode. Provisions shall be included to automatically place the voltage regulator in the proper mode of operation when the diesel-generator unit is required to operate automatically (see 4.5.2.2). The voltage regulator shall be placed in isochronous (emergency) mode when in standby.
4.5.1.6 Generator output circuit breaker
The generator output circuit breaker is necessary to support the testing requirements delineated in this standard where the emergency diesel generator (EDG) shall be connected to the Class 1E bus to accomplish testing as required/defned in 7.4 (Periodic testing) and 7.5(Test descriptions).
These include:
a) Energizing the Class 1E bus to support EDG loading tests
b) Energizing the isolated bus for loss of ofsite power (LOOP) and LOOP/safety injection Actuation signal (SIAS) and shutdown testing c) Restoring the diesel loads back to preferred power supply Circuit breaker design and testing features shall follow the IEEE C37 standards identifed in Annex E, where appropriate.
4.5.1.7 Fuel oil storage and supply systems
The fuel oil storage and supply systems are necessary to support the operation and function of the EDG. System-specifc design and component features are included in ANS 59.51, Fuel Oil Systems for Emergency Diesel Generators.
4.5.2 Control
4.5.2.1 Control modes
The diesel-generator unit shall be provided with control systems permitting automatic and manual control.
4.5.2.2 Emergency control
Upon receipt of an emergency start signal, the automatic control system shall provide automatic start-up and automatic adjustment of speed and voltage to a ready-to-load condition in the emergency (isochronous) mode according to the following conditions:
a) An emergency start signal shall override all other operating modes and return control of the diesel- generator unit to the automatic control system.
b) An emergency start signal shall not override any manual non-operating modes such as those for repair and maintenance.
4.5.2.3 Control points
Provisions shall be made for control both from the control room and external to the control room.
4.5.2.4 Control power
Dedicated battery systems for control power, starting, and feld fashing shall be sized per IEEE Std 485™, or IEEE Std 1115™, and according to postulated number of starts over an extended duration without capability to recharge.IEEE Std 387 pdf download.