1 Description
2 Mask and Parameters
- 2.1 GGOV1 Parameters
- 2.2 Initial Values
- 2.3 Block Diagram Tab
3 Inputs and Outputs and Additional Signal Available for Monitoring
- 3.1 Inputs
- 3.2 Output
4 References

Description

This model is a natural gas turbine-governor dynamic model. The GGOV1 was initially developed for GE heavy frame machines. But it has also been used to represent the turbine-governor model of other manufacturers as well. The component was developed in line with the reference [1]. Figure 1 and 2 below shows the block diagram representing the GGOV1 governor [1-2].

Figure 1 Implementation of GGOV1 when Kpgov and Kpload are equal to 0

The implementation presented in Figure 2 is used when Kpgov and Kpload are different form 0. In case Kpgov and Kpload are equal to 0, the implementation presented in Figure 1 is used.

If Kpgov=0. the integrator Kigov/s is moved back in parallel to the derivative Kdgov/Tdgov control.
If Kpload =0, the integrator Kiload/s is fed by input to Kpload and output to Fsrt.

An additional equation is also implemented to calculate the load reference (Lref) based on the control configuration (RSelect) and the temperature effect. The equations used for Lref are presented in the table below.

Configuration	Load reference
Rselect=1	Lref=w_ic+R*0
Rselect=2	Lref=w_ic+wf_ic*R= w_ic +(Pm_IC/Kturb)+Wfnl
Rselect=3	Lref=w_ic+wf_ic*R= w_ic +(Pm_IC/Kturb)+Wfnl
Rselect=4	Lref=w_ic+wf_icR= w_ic +Pelec_ICR

The load reference, Lref, is summed to the Pref signal Lref+Pref. In this case, Pref is a variation of the load reference. Pref represents a variation in HS, Lref is calculated internally in the implementation. In PSSE, the load reference, Lref, is obtained at the initialization with the governor parameters and the LF results, the equations used for Lref are presented in Table 1.

Mask and Parameters

GGOV1 Parameters

Each parts of the governor are available to see from when expanding the diagrams.

The model has the following parameters:

Name	Description	Unit	Default value
R	Permanent droop(pu)	pu	0.04
Tpelec	Electrical power transducer time constant(sec)	s	1
maxerr	Maximum value for speed error signal	pu	0.05
minerr	Minimum value for speed error signal	pu	-0.05
Kpgov	Gov. proportional gain	-	10
Kigov	Gov. integral gain	-	2
Kdgov	Gov. derivative gain	-	0
Tdgov	Gov. derivative controller time constant(sec)	s	1
Vmax	Maximum valve position limit	pu	1
Vmin	Minimum valve position limit	pu	0.1
Tact	Actuator time constant(sec)	s	0.5
Kturb	Turbine gain	-	1.5
Wnfl	No load fuel flow(pu)	pu	0.2
Tb	Turbine lag time constant(sec)	s	0.1
Tc	Turbine lead time constant(sec)	s	0
Teng	Transport lag time constant for diesel engine(sec)	s	0
Tfload	Load Limiter time constant(sec)	s	3
Kpload	Load limiter proportional gain for PI controller	-	2
Kiload	Load limiter integral gain for PI controller	-	0.67
Ldref	Load limiter reference value(pu)	pu	1
Dm	Mechanical damping coefficient(pu)	pu	0
ropen	Maximum valve opening rate(pu/sec)	pu/s	0.1
rclose	Maximum valve closing rate(pu/sec)	pu/s	-0.1
Kimw	Power controller (reset) gain	-	0.01
Aset	Acceleration limiter setpoint(pu/sec)	pu/s	0.01
Ka	Acceleration limiter gain	-	10
Ta	Acceleration limiter time constant(sec)	s	1
db	Deadband	pu	0
Tsa	Temperature detection lead time constant, sec.	s	4
Tsb	Temperature detection lag time constant, sec.	s	5

The configurations parameters are shown in the table below.

Name

Description

Unit

Rselet

1 none (isochronous governor)

2 governor output (requested stroke)

3 fuel valve stroke (true stroke)

4 electrical power

-

Flag

0 fuel flow proportional to speed

1 fuel flow independent of speed

-

Initial Values

Name	Unit	Description
Pmwset	pu	Power controller setpoint
Pm0	pu	Initial mechanical power output
w0	pu	Speed reference

The initial values parameters can be set manually, by entering a numerical value. They can also be set automatically based on load flow calculations, by entering a referenced synchronous machine variable. For instance, if the name of the synchronous machine on which the governor/turbine is connected is “SM1”, then the values should be inserted as follow (if the machine is defined as PV type):

Name	Unit	Value
Pmwset	pu	SM1.lfP/1e6/SM1.sBase
Pm0	pu	SM1.lfP/1e6/SM1.sBase+3SM1.Rs((sqrt(SM1.lfP^2+SM1.lfQ^2)/1e6/SM1.sBase)/sqrt(3)/SM1.lfVolt)^2
w0	pu	SM1.Wm_Init

If the machine is defined as a swing type:

Name	Unit	Value
Pmwset	pu	BusName.LF_Pbus/SM1.sBase
Pm0	pu	BusName.LF_Pbus/SM1.sBase+3SM1.Rs((sqrt(SM1.lfP^2+SM1.lfQ^2)/1e6/SM1.sBase)/sqrt(3)/SM1.lfVolt)^2

The HYPERSIM simulation option “Set Initial Conditions” must be checked for the automatic initialization to work properly.

Block Diagram Tab

This tab is showing the complete diagram of the GGOV1 governor.

Inputs and Outputs and Additional Signal Available for Monitoring

Inputs

Input	Description	Unit
w	Machine actual speed	pu
Pref	External control reference	pu
Pelec	Measured electrical power	pu

Output

Input	Description	Unit
Pm	Mechanical power output	pu

References

[1] PSS®E 34.2.0 Model Library. NY, USA: Siemens Industry, Inc., 2017.

[2] Reliability Guideline: Application Guide for Modeling Turbine-Governor and Active Power-Frequency Controls in Interconnection-Wide Stability Studies., 2019.