
This component models an IEEE type 2 hydro governor and turbine and was created specifically to retrofit the later, more compact version of the V2 SNC375 Machine Model (Obsolete). It is included in the PSCAD V4 Master Library for compatibility reasons.
Inputs:
SP: The reference speed [pu].
Tm0: Mechanical torque from the machine [pu].
w: Machine rotor speed [rad/s].
Outputs:
Tm: Mechanical torque output [pu].
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NOTE: See Hydro Governor Transfer Functions for more details.
Name for Identification |
Text |
Optional text parameter for identification of the component. |
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Base Frequency |
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REAL |
Constant |
Enter the system base frequency for per-unitizing [Hz] |
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Controller Real Pole Gain |
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REAL |
Constant |
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Controller Proportional Gain |
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REAL |
Constant |
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Controller Integral Gain |
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REAL |
Constant |
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Controller Real Pole Time Constant |
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REAL |
Constant |
[s] |
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Turbine Lead Time Constant |
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REAL |
Constant |
[s] |
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Turbine Lag Time Constant |
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REAL |
Constant |
[s] |
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Governor Time Constant |
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REAL |
Constant |
[s] |
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Inverse Gate Velocity Limit |
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REAL |
Constant |
Physically, this is the time required, in seconds, for the gate to go from fully closed to fully open [s/pu] |
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Gate Velocity Time Constant |
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REAL |
Constant |
[s] |
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Permanent Droop Gain |
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REAL |
Constant |
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Gate Position Control Rate Limit |
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REAL |
Constant |
This limits the rate at which the 'desired gate position' signal may change [pu/s] |
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Temporary Droop Gain |
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REAL |
Constant |
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Temporary Droop Time Constant |
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REAL |
Constant |
[s] |
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Conversion Constant |
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REAL |
Constant |
Conversion constant from per-unit gate position to per-unit mechanical torque.
Example: A 120MVA generator operates at a power factor of 0.85. The rated turbine output must be 0.85x120 or 102 MW. If the turbine is designed to deliver this power at 95% gate, the power rating of the turbine would be 102/0.95 or 107.4 MW. Thus this conversion constant is 107.4/120.0 or 0.89.
Note that the governor output is limited by the Conversion Constant parameter. If the machine output is more than the Conversion Constant at the time of transition, when the governor is released, it will restrict the output to the Conversion Constant and the machine speed will drop. Hence take this factor into consideration while loading the machine. |
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Time Constant for Smoothing TmO |
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REAL |
Variable |
The mechanical torque from the machine needs to be smoothed to remove any ripple before it can be used for initializing the governor. The Tm0 input is passed through a real pole block with this time constant before it is used. This block is not a part of the governor dynamics and it is active only during the initialization [s] |
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Initialization switch: 0-Init; 1-Release |
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INTEGER |
Variable |
Use the machine initialization switch here. During the initialization period (0), the governor will continuously initialize itself to the machine's mechanical torque output. Thus when the machine is released, the governor will output the machine torque from its last time step and the transition will be smooth. This also avoids the need to supply the initial mechanical torque. |