Implements IEEE type ST2A excitation system model
Simscape / Electrical / Specialized Power Systems / Fundamental Blocks / Machines / Excitation Systems
This block models a compound source rectifier excitation system. It utilizes both terminal voltage, Vt, and terminal current, It, to form a model of the exciter power source.
This block is an adaptation of the ST2A excitation system of the IEEE® 421 standard, copyright IEEE 2005, all rights reserved.
The time constant Tr of the first-order system representing
the stator terminal voltage transducer. Default is
The gain Ka and time constant Ta of the first-order system representing
the main regulator. Default is
The voltage regulator output limits VRmin and VRmax, in p.u.
The gain Kf and time constant Tf of the first-order system representing
the derivative feedback. Default is
The gain Ke and time constant Te of the first-order system representing
the exciter. Default is
The current circuit gain coefficient. Default is
The potential circuit gain coefficient. Default is
Enter the value of the Xd reactance of the controlled Synchronous
Machine block. Default is
The rectifier loading factor, proportional to commutating reactance.
The initial values of terminal voltage Vt0 and field voltage
Efd0, both in p.u. Initial terminal voltage is normally set to 1 pu.
The Vt0 and Efd0 values can be determined using the Powergui Load
Flow tool. Default is
The initial value of terminal current It0, in p.u. This value
can be determined using the Powergui Load Flow tool. Default is
Specify a value greater than zero to discretize the block at
the given sample time. Set to -1 to inherit the simulation type and
sample time parameters of the Powergui block. Default
The reference value of the stator terminal voltage, in p.u.
The measured value in p.u. of the stator terminal voltage of the controlled Synchronous Machine block.
It The measured value in p.u. of the stator terminal current of the controlled Synchronous Machine block.
The measured value in p.u. of the stator field current of the controlled Synchronous Machine block.
Connect this input to a power system stabilizer to provide additional stabilization of power system oscillations. When you do not use this option, connect to a Simulink® ground block. The input is in p.u.
The field voltage to apply to the
of the controlled Synchronous Machine block. The output
is in p.u.
power_machines example contains a Configurable
Subsystem block that allows you to select between seven types
of excitation systems to control the terminal voltage of the Synchronous
Machine block. This configurable block refers to the
library that contains seven pretuned excitation system blocks that
fit simulation requirements for this example.
Right-click the EXCITATION configurable block, then select ST2A from the Block Choice menu to control the Synchronous Machine block using the ST2A Excitation System block.
 “IEEE Recommended Practice for Excitation System Models for Power System Stability Studies.” IEEE Standard, Vol. 421, No. 5, 2005 (Revision of IEEE 521.5-1992).