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Component Class

This page explains the variables and functions used in the component class (component).

Contents:

Component Class

The component class is one of the "super classes" in GUILDA. As the name implies, a component is a piece of equipment, such as generators or loads. There are three main child classes that are derived from the component class: 1. Empty Component (component_empty), 2. Generator (generator_1axis), 3. Load (load_impedance).

graph TD component---component_empty component---generator_1axis component---load_impedance

The component super class is composed of

Abstract Methods

Set Equilibrium (set_equilibrium(obj,Veq,Ieq))

This method performs the initialization processing, determines the equilibrium points via power flow calculation (equilibrium voltage \(\small (V_{eq})\) and equilibrium current \(\small (I_{eq})\)), and derives the equilibrium state.

Structure: x = set_equilibrium(obj,Veq,Ieq)

Input Arguments

  • Veq: Equilibrium point of the voltage (complex number) \(-\) obtained from the power flow calculation.

  • Ieq: Equilibrium point of the current (complex number) \(-\) obtained from the power flow calculation.

Output Parameters

  • x：Equilibrium state corresponding to the specified equilibrium point.

Input State Order (get_nu(obj))

This method is used to determine the order of the input state (u).

Class Structure nu = get_nu(obj)

Input Arguments

  • None

Output Parameters

  • nu：Order of input state (u).

State Derivative (get_dx_constraint(obj,t, x, V, I, u))

This method is used to obtain the derivative of the state \(\small (x)\); when an input is applied it also provides the derivative of the current \(\small (I)\).

Class Structure: [dx,constraint] = get_dx_constraint(obj,t, x, V, I, u)

Input Arguments

  • t: Time \(\small (t)\).
  • x: State \(\small (x)\).
  • V: Busbar Voltage \(\small (V)\) ([real part; imaginary part]).
  • I: Busbar Current \(\small (I)\) ([real part; imaginary part]).
  • u: Input Signal \(\small (u)\).

Output arguments

  • dx：Derivative of the State \(\small (\dot{x})\).

  • constraint：The difference between the actual busbar's current \(\small (I)\) and the derived one from the provided arguments "state" \(\small (x)\) and "voltage" \(\small (V)\). The constraint condition is that the difference between both currents \(\small (I)\) should be zero.

Empty Component

This child class implements an empty device (component_empty), that means that it only inherits all the characteristics of the parent class, but doesn't add anything.

Generator

This child class implementats a generator model. In GUILDA a 1-Axis Synchronous Generator Model is used (generator_1axis).

Variables

Generator Parameters (x)

  • Xd: Synchronous Reactance around the d-axis \(\small (X_d)\).

  • Xq: Synchronous Reactance around the q-axis \(\small (X_q)\).

  • Xd_prime: Transient Synchronous Reactance around the d-axis \(\small (X'_d)\).

  • T：Time constant of the field current around the d-axis \(\small (\tau)\).

  • M：Inertia Coefficient \(\small (M)\).

  • D：Damping Factor \(\small (D)\).

Equilibrium State (x_equilibrium)

Equilibrium point of the internal state of the generator

  • delta：Rotor declination angle \(\small (\delta)\).

  • omega：Angular frequency deviation \(\small (\Delta \omega)\).

  • E：Internal voltage \(\small (E)\).

  • x_avr：Automatic Voltage Regulator (AVR) State.

  • x_gov：Governor State.

  • x_pss：Power System Stabilizer (PSS) State.

Equilibrium Voltage (V_equilibrium)

Array containing the Equilibrium Voltage \(\small (V)\) ([real part; imaginary part]).

Equilibrium Current (I_equilibrium)

Array containing the Equilibrium Current \(\small (I)\) ([real part; imaginary part]).

Automatic Voltage Regulator (AVR) Controller (set_avr)

  • Ka：AVR Gain.

  • Te：Exciter Time Constant.

Governor

  • governor：Instance of the governor class.

Power System Stabilizer (set_pss)

  • Kpss: PSS Gain.

  • Tpss: Washout Filter Time Constant.

  • TL1p, TL1: Phase Advance-Delay Time Constant of the First Stage.

  • TL2p, TL2: Phase Advance-Delay Time Constant of the Second Stage.

  • omega0：Reference Angular Frequency (Grid's frequency \(\small (\omega_0)\)).

Methods

obj = generator_1axis(omega, parameter)

  • omega：Reference Angular Frequency (Grid's frequency \(\small (\omega_0)\)).

  • parameter：Generator parameters (see above).

Load

This child class implements a constant impedance load model (load_impedance).

Methods

obj = load_impedance(varargin)

Impedance values are determined from equilibrium voltage and equilibrium current; thus, no arguments are required.