SM PSS1A

Discrete-time or continuous-time single input PSS1A power system stabilizer

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Libraries:
Simscape / Electrical / Control / SM Control

Description

The SM PSS1A block implements a single-input PSS1A power system stabilizer (PSS) that maintains rotor angle stability in a synchronous machine (SM) in conformance with IEEE 421.5-2016^[1]. Typically, you use a PSS to enhance the damping of power system oscillations through excitation control.

You can switch between continuous and discrete implementations of the block by using the Sample time (-1 for inherited) parameter. To configure the integrator for continuous time, set the Sample time (-1 for inherited) property to 0. To configure the integrator for discrete time, set the Sample time (-1 for inherited) property to a positive, nonzero value, or to -1 to inherit the sample time from an upstream block.

This diagram illustrates the overall structure of the PSS1A power system stabilizer:

In the diagram:

• V_SI is the power system stabilizer input. Commonly used inputs are speed, frequency, or power. For more information, see V_SI.

• The Low-Pass Filter (Discrete or Continuous) block can be used to model a transducer, with a time constant T₆.

• K_s models the stabilizer gain.

• The Washout (Discrete or Continuous) block models a high-pass filter. Here, T₅ is the time constant.

• The Second-Order Low-Pass Filter (Discrete or Continuous) block takes into account the low-frequency effects of the high-frequency torsional filters. Here, A₁ and A₂ are the stabilizer denominator constants for the second-order block.

• The two Lead-Lag (Discrete or Continuous) blocks models additional dynamics associated with the power system stabilizer, and represent two stages of the lead-lag compensation.

Ports

Input

V_SI — Speed, frequency, or power

scalar

Per-unit speed, frequency of the terminal bus voltage, compensated frequency, or electrical power, specified as a scalar.

Data Types: single | double

Output

V_ST — Stabilization speed, frequency, or power

scalar

Automatic voltage regulator input stabilization signal, as limited by V_{ST_min} and V_{ST_max}, returned as a scalar.

Data Types: single | double

Parameters

Power system stabilizer (PSS) gain, K_S (pu) — Power system stabilizer gain

3.15 (default) | scalar

Power system stabilizer forward path gain.

PSS denominator constant for second-order block, A_1 — Filter constant 1

0 (default) | scalar

Power system stabilizer signal conditioning filter coefficient 1.

PSS denominator constant for second-order block, A_2 — Filter constant 2

0 (default) | scalar

Power system stabilizer signal conditioning filter coefficient 2.

PSS numerator (lead) compensating time constant, T_1 (s) — Lead time constant 1

0.76 (default) | scalar

Lead time constant 1, associated with the first Lead-Lag block in the diagram.

PSS denominator (lag) compensating time constant, T_2 (s) — Lag time constant 2

0.01 (default) | scalar

Lag time constant 2, associated with the first Lead-Lag block in the diagram.

PSS numerator (lead) compensating time constant, T_3 (s) — Lead time constant 3

0.76 (default) | scalar

Lead time constant 3, associated with the second Lead-Lag block in the diagram.

PSS denominator (lag) compensating time constant, T_4 (s) — Lag time constant 4

0.01 (default) | scalar

Lag time constant 4, associated with the second Lead-Lag block in the diagram.

PSS washout time constant, T_5 (s) — Washout time constant

10 (default) | scalar

Washout time constant, associated with the Washout block in the diagram.

PSS transducer time constant, T_6 (s) — Transducer time constant

0 (default) | scalar

Transducer time constant, associated with the Low-Pass Filter block in the diagram.

Maximum PSS output, V_STmax (pu) — Maximum stabilization

0.09 (default) | scalar

Maximum power system stabilizer output to the automatic voltage regulator (AVR).

Minimum PSS output, V_STmin (pu) — Minimum stabilization

-0.09 (default) | scalar

Minimum power system stabilizer output to the automatic voltage regulator (AVR).

Sample time (-1 for inherited) — Block sample time

-1 (default) | 0 | positive scalar

Time between consecutive block executions. During execution, the block produces outputs and, if appropriate, updates its internal state. For more information, see What Is Sample Time? and Specify Sample Time.

For inherited discrete-time operation, set the sample time to -1. For discrete-time operation, set the sample time to a positive scalar. For continuous-time operation, set the sample time to 0.

References

[1] IEEE Recommended Practice for Excitation System Models for Power System Stability Studies. IEEE Std 421.5-2016. Piscataway, NJ: IEEE-SA, 2016.

[2] Kundur, P. Power System Stability and Control. New York, NY: McGraw Hill, 1993.

Extended Capabilities

C/C++ Code Generation
Generate C and C++ code using Simulink® Coder™.

Version History

Introduced in R2018b