PSS2C

PSS2C model

This article is incomplete, some sections must be written.

Context

This power system stabilizer model first appeared in the IEEE Std 421.5-2016 [1]. It has been reproduced identically in the IEC 61970-302:2024 version [2]. In the previous standard versions, its predecessor models were called PSS2A (1992, 2005) and PSS2B (2005). Compared to PSS2A, PSS2B has a third lead-lag compensation block. Compared to PSS2B, PSS2C has a fourth lead-lag compensation block and an output logic.

Model use, assumptions, validity domain and limitations

To be completed

Model inputs and output

The input variables are :

Variable	Description	Units
\(\omega_{pu}\)	measured angular frequency	\(pu\) (base \(\omega_{Nom}\))
\(\omega_{RefPu}\)	reference angular frequency	\(pu\) (base \(\omega_{Nom}\))
\(P_{GenPu}\)	active power	\(pu\) (base \(S_{nRef}\))

The output signal is \(VPssPu\) in \(pu\) (base \(U_{Nom}\)).

Model parameters

Parameter	Description	Units
\(K_{\Omega}\)	Coefficient applied to angular frequency	-
\(K_{\Omega Ref}\)	Coefficient applied to reference angular frequency	-
\(K_{s1}\)	Gain of power system stabilizer	\(pu\)
\(K_{s2}\)	Gain of transducer (active power branch)	\(pu\)
\(K_{s3}\)	Washouts coupling factor	\(pu\)
\(M\)	Lag order of ramp-tracking filter	-
\(N\)	Order of ramp-tracking filter	-
\(\Omega_{MaxPu}\)	Maximum angular frequency input of power system stabilizer	\(pu\) (base \(\omega_{Nom}\))
\(\Omega_{MinPu}\)	Minimum angular frequency input of power system stabilizer	\(pu\) (base \(\omega_{Nom}\))
\(P_{GenMaxPu}\)	Maximum active power input of power system stabilizer	\(pu\) (base \(S_{Nom}\)) (generator convention)
\(P_{GenMinPu}\)	Minimum active power input of power system stabilizer	\(pu\) (base \(S_{Nom}\)) (generator convention)
\(PPssOffPu\)	Active power threshold for PSS deactivation	\(pu\) (base \(S_{Nom}\)) (generator convention)
\(PPssOnPu\)	Active power threshold for PSS activation	\(pu\) (base \(S_{Nom}\)) (generator convention)
\(t1\)	First lead time constant	\(s\)
\(t2\)	First lag time constant	\(s\)
\(t3\)	Second lead time constant	\(s\)
\(t4\)	Second lag time constant	\(s\)
\(t6\)	Transducer time constant of angular frequency branch	\(s\)
\(t7\)	Transducer time constant of active power branch	\(s\)
\(t8\)	Ramp-tracking filter lead time constant	\(s\)
\(t9\)	Ramp-tracking filter lag time constant	\(s\)
\(t10\)	Third lead time constant	\(s\)
\(t11\)	Third lag time constant	\(s\)
\(t12\)	Fourth lead time constant	\(s\)
\(t13\)	Fourth lag time constant	\(s\)
\(tW1\)	First washout time constant (angular frequency branch)	\(s\)
\(tW2\)	Second washout time constant (angular frequency branch)	\(s\)
\(tW3\)	First washout time constant (active power branch)	\(s\)
\(tW4\)	Second washout time constant (active power branch)	\(s\)
\(VPssMaxPu\)	Maximum voltage output of power system stabilizer	\(pu\) (base \(U_{Nom}\))
\(VPssMinPu\)	Minimum voltage output of power system stabilizer	\(pu\) (base \(U_{Nom}\))
\(S_{Nom}\)	Nominal apparent power	\(MVA\)

Model diagram

Figure 1: PSS2C

Model variants

In the PSS2A and PSS2B models :

• the PSS deactivation for low active power values is absent \((PPssOffPu = -1000, PPssOnPu = -999)\)
• the final lead-lag filter is ignored \((t12 = t13 = 0)\)

Moreover, in the PSS2A model, the second to last lead-lag filter is ignored \((t10 = t11 = 0)\).

Open source implementations

This model has been successfully implemented in :

Software	URL	Language	Open-Source License	Last consulted date	Comments
Dynawo	Link	Modelica	MPL v2.0	24/05/2024

References

1.

Electrical TI of, Engineers E (2016) IEEE recommended practice for excitation system models for power system stability studies. IEEE Std 4215-2016

2.

Commission IE (2024) Energy management system application program interface (EMS-API) part 302: Common information model (CIM) dynamics. IEC 61970-302