The PSS2A model was developed in line with the references [1] [2]. Figure 1 shows the architecture of the PSS2A model. PSS2A is a dual-input stabilizer. This model can represent a variety of stabilizers with inputs of power, speed, or frequency [1].

Symbol

Mask parameters

Name	Description	Unit	Hard coded parameter range
T1, T3	PSS lead compensating time constant	s	-
T2, T4	PSS lag compensating time constant	s	-
Tw1, Tw2, Tw3, Tw4	PSS washout time constant	s	-
T6	Transducer time constant	s	-
T7	Transducer time constant	s	-
T8	Lead time constant of ramp tracking filter	s	-
T9	Lag time constant of ramp tracking filter	s	-
M, N	Ramp tracking filter constant	-	0≤M≤5 0≤N≤4 M, N are integers
Ks1, Ks2, Ks3	PSS gains	-	-
VSTmax	Maximum PSS output	pu	-
VSTmin	Minimum PSS output	pu	-
W0	Rotor speed/frequency reference (Wref in the diagram)	pu	-
Pe0	Electrical active power reference (Pref in the diagram)	pu	-

For all transfer functions, the degree of the numerator must be less than or equal to the denominator. The user must be aware of this restriction at all times.

The parameters Pe0 and W0 can be set manually by entering a numerical value. It 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 in the genunit to which the stabilizer is connected is “SM1”, then Pe0 and W0 shall be set respectively as “=SM1.Peo/SM1.BaseMVA” and “=SM1.wo” if a thermal machine or a hydraulic machine is used, and as "=SM1.lfP/1e6/SM1.sBase" and "=SM1.Wm_Init" if a pu standard or pu fundamental machine is used. For example:

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

Input/Output signals

Name	Description	Type
VSI1	Power system stabilizer model input (speed or frequency)	Input
VSI2	Power system stabilizer model input (electrical power)	Input
VST	Power system stabilizer model output	Output

Sensor descriptions

Name	Description	Unit
VSI1	Power system stabilizer model input (speed or frequency)	pu
VSI2	Power system stabilizer model input (electrical power)	pu
VST	Power system stabilizer model output	pu

References

[1] Siemens Industry, Inc. Siemens Power Technologies International, "PSS®E 34.2.0 MODEL LIBRARY," April 2017.

[2] IEEE, , "IEEE Recommended Practice for Excitation System Models for Power System Stability Studies," IEEE Std 421.5-1992, pp. 1-56, 10 Aug. 1992.