Electrical Algebraic Component

Purpose

Define an algebraic constraint in terms of voltage and current

Library

Electrical / Passive Components

Description

The Electrical Algebraic Component enforces an arbitrary algebraic constraint involving voltage and current. The small dot marks the positive terminal.

The output signal v measures the voltage across the component from the positive to the negative terminal. The output signal i measures the current flowing into the positive terminal. The two output signals must affect the input signal 0 by means of a direct feedthrough path. The component ensures that the input signal is zero at all times.

The direct feedthrough path defines a function \(f(v,i)\), which in turn implicitly determines the current-voltage characteristic of the component through the constraint \(f(v,i)=0\). For instance, the choice \(f(v,i):=v-R\cdot i\) causes the Electrical Algebraic Component to act as an ideal resistor with resistance \(R\).

The Electrical Algebraic Component can be vectorized. The three signals v, i and 0 must have the same width.

Fig. 190 shows a possible implementation of a variable resistor.

Fig. 190 Possible implementation of a variable resistor.

There is also a Variable Resistor component in the library.

Note

The Electrical Algebraic Component creates an algebraic loop. See section Block Sorting for more information on algebraic loops.

Example Model

• See the example model “Algebraic Component”.

• Find it in PLECS under Help > PLECS Documentation > List of Example Models.

Probe Signals

Component voltage

The voltage measured across the component from the positive to the negative terminal.

Component current

The current flowing into the positive terminal of the component.

Component power

The power consumed by the component.