1 Description
2 Mask and Parameters
- 2.1 IEESGO Parameters
- 2.2 Initial Values
3 Inputs and Outputs and Additional Signal Available for Monitoring
- 3.1 Inputs
- 3.2 Outputs
4 References

Description

The IEESGO is a steam turbine model improved in 1973 from the TGOV1 model from IEEE. This model represents the turbine-governor droop with lead-lag (K1, T1, T2, T3), the main steam control valve motion and limits (T4, P_MAX, P_MIN), the reheater control (K2, T5) and the IP-LP power contribution (K3, T6). Two turbine fractions are introduced (K2 and K3) to represent different stages in the steam turbine. The IEESGO model was developed in line with the governor-turbine architecture given in the references [1-3]. Figure 1 shows the architecture of the IEESGO model. Figure 2 shows the symbol of the IEESGO governor-turbine model.

Figure 1 IEESGO governor-turbine model

Figure 2 IEESGO governor model

Mask and Parameters

IEESGO 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

Name	Description	Unit	Default value
K1	1/per unit regulation	-	20
T1	Controller lag	s	0.15
T2	Controller lead compensation	s	0
T3	Governor lag	s	0.13
P_MAX*	Upper power limit	pu	0.982
P_MIN*	Lower power limit	pu	0
T4	Delay due to steam inlet volumes associated with steam chest and inlet piping	s	0.22
K2	Fraction	-	0.747
T5	Reheater delay including hot and cold leads	s	4.97
K3	Fraction	-	0.631
T6	Delay due to IP-LP turbine, crossover pipes and LP end hoods	s	0.2

Initial Values

Name	Description	Unit
Pm0	Initial mechanical power output	pu

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	Description
Pm0	pu	SM1.lfP/1e6/SM1.sBase+3SM1.Rs((sqrt(SM1.lfP^2+SM1.lfQ^2)/1e6/SM1.sBase)/sqrt(3)/SM1.lfVolt)^2

If the machine is defined as a swing type:

Name	Unit	Description
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.

Inputs and Outputs and Additional Signal Available for Monitoring

Inputs

Input	Description	Unit
P0	External control reference	pu
w	Machine actual speed	pu

Outputs

Input	Description	Unit
Pm	Mechanical power output	pu

References

[1] P. Kundur, “Power System Stability and Control”, McGraw-Hill 1994

[2] Standard Dynamic Turbine-Governor Systems in NEPLAN Power System Analysis Tool

[3] PSSE Explore 34 Siemens software