GeneratingUnit

Class Description

A single or set of synchronous machines for converting mechanical power into alternating-current power. For example, individual machines within a set may be defined for scheduling purposes while a single control signal is derived for the set. In this case there would be a GeneratingUnit for each member of the set and an additional GeneratingUnit corresponding to the set.

Attributes

Name Type Description
allocSpinResP ActivePower The planned unused capacity (spinning reserve) which can be used to support emergency load.
autoCntrlMarginP ActivePower The planned unused capacity which can be used to support automatic control overruns.
baseP ActivePower For dispatchable units, this value represents the economic active power basepoint, for units that are not dispatchable, this value represents the fixed generation value. The value shall be between the operating low and high limits.
controlDeadband ActivePower Unit control error deadband. When a unit’s desired active power change is less than this deadband, then no control pulses will be sent to the unit.
controlPulseHigh Seconds Pulse high limit which is the largest control pulse that the unit can respond to.
controlPulseLow Seconds Pulse low limit which is the smallest control pulse that the unit can respond to.
controlResponseRate ActivePowerChangeRate Unit response rate which specifies the active power change for a control pulse of one second in the most responsive loading level of the unit.
efficiency PerCent The efficiency of the unit in converting mechanical energy, from the prime mover, into electrical energy.
genControlMode GeneratorControlMode The unit control mode.
genControlSource GeneratorControlSource The source of controls for a generating unit. Defines the control status of the generating unit.
governorMPL PU Governor motor position limit.
governorSCD PerCent Governor Speed Changer Droop. This is the change in generator power output divided by the change in frequency normalized by the nominal power of the generator and the nominal frequency and expressed in percent and negated. A positive value of speed change droop provides additional generator output upon a drop in frequency.
highControlLimit ActivePower High limit for secondary (AGC) control.
initialP ActivePower Default initial active power which is used to store a powerflow result for the initial active power for this unit in this network configuration.
longPF Float Generating unit long term economic participation factor.
lowControlLimit ActivePower Low limit for secondary (AGC) control.
lowerRampRate ActivePowerChangeRate The normal maximum rate the generating unit active power output can be lowered by control actions.
maxEconomicP ActivePower Maximum high economic active power limit, that should not exceed the maximum operating active power limit.
maximumAllowableSpinningReserve ActivePower Maximum allowable spinning reserve. Spinning reserve will never be considered greater than this value regardless of the current operating point.
maxOperatingP ActivePower This is the maximum operating active power limit the dispatcher can enter for this unit.
minEconomicP ActivePower Low economic active power limit that shall be greater than or equal to the minimum operating active power limit.
minimumOffTime Seconds Minimum time interval between unit shutdown and startup.
minOperatingP ActivePower This is the minimum operating active power limit the dispatcher can enter for this unit.
modelDetail Classification Detail level of the generator model data.
nominalP ActivePower The nominal power of the generating unit. Used to give precise meaning to percentage based attributes such as the governor speed change droop (governorSCD attribute).
The attribute shall be a positive value equal to or less than RotatingMachine.ratedS.
normalPF Float Generating unit economic participation factor. The sum of the participation factors across generating units does not have to sum to one. It is used for representing distributed slack participation factor. The attribute shall be a positive value or zero.
penaltyFactor Float Defined as: 1 / ( 1 - Incremental Transmission Loss); with the Incremental Transmission Loss expressed as a plus or minus value. The typical range of penalty factors is (0.9 to 1.1).
raiseRampRate ActivePowerChangeRate The normal maximum rate the generating unit active power output can be raised by control actions.
ratedGrossMaxP ActivePower The unit’s gross rated maximum capacity (book value).
The attribute shall be a positive value.
ratedGrossMinP ActivePower The gross rated minimum generation level which the unit can safely operate at while delivering power to the transmission grid.
The attribute shall be a positive value.
ratedNetMaxP ActivePower The net rated maximum capacity determined by subtracting the auxiliary power used to operate the internal plant machinery from the rated gross maximum capacity.
The attribute shall be a positive value.
shortPF Float Generating unit short term economic participation factor.
startupCost Money The initial startup cost incurred for each start of the GeneratingUnit.
startupTime Seconds Time it takes to get the unit on-line, from the time that the prime mover mechanical power is applied.
tieLinePF Float Generating unit economic participation factor.
totalEfficiency PerCent The efficiency of the unit in converting the fuel into electrical energy.
variableCost Money The variable cost component of production per unit of ActivePower.

Relationships

Inherits from

Descendant classes

Leaf/Root class

IsLeaf IsRoot
False False

Associations

Source Class Cardinality Source Target Class Cardinality Target Source Name Source Assoc. Description Target Name Target Assoc. Description
GenUnitOpCostCurve 0..* GeneratingUnit 1 GenUnitOpCostCurves A generating unit may have one or more cost curves, depending upon fuel mixture and fuel cost. GeneratingUnit A generating unit may have one or more cost curves, depending upon fuel mixture and fuel cost.
GenUnitOpSchedule 0..1 GeneratingUnit 1 GenUnitOpSchedule A generating unit may have an operating schedule, indicating the planned operation of the unit. GeneratingUnit A generating unit may have an operating schedule, indicating the planned operation of the unit.
GeneratingUnit 0..1 RotatingMachine 0..* GeneratingUnit A synchronous machine may operate as a generator and as such becomes a member of a generating unit. RotatingMachine A synchronous machine may operate as a generator and as such becomes a member of a generating unit.
GrossToNetActivePowerCurve 0..* GeneratingUnit 1 GrossToNetActivePowerCurves A generating unit may have a gross active power to net active power curve, describing the losses and auxiliary power requirements of the unit. GeneratingUnit A generating unit may have a gross active power to net active power curve, describing the losses and auxiliary power requirements of the unit.
ControlAreaGeneratingUnit 0..* GeneratingUnit 1 ControlAreaGeneratingUnit ControlArea specifications for this generating unit. GeneratingUnit The generating unit specified for this control area. Note that a control area should include a GeneratingUnit only once.