Switch Loss Calculator

Purpose

Calculate the average sum of the switch losses of all probed components over the specified averaging period

Library

System

Description

This block provides a shortcut for calculating the summed average switch losses of one or more switch components. You can choose to calculate the conduction losses, the switching losses (optionally separated into turn-on losses and turn-off losses) and the total losses (comprising the conduction and switching losses). The output signal is a vector comprising the selected loss types.

Optionally, you may group the losses by switch type, i.e. calculate individual sums for the separate switch types by checking the box Group by switch type. If, for example, the list of components contains a number of diodes and MOSFETs and you have chosen to calculate conduction and switching losses, the output vector will be ordered as follows:

Sum of diode conduction losses
Sum of diode switching losses
Sum of MOSFET conduction losses
Sum of MOSFET switching losses

To add switch components to the list of components, select them in the schematic editor and drag them onto the list or the Switch Loss Calculator block. The block accepts all switch components that implement the thermal loss model (see Supported Devices).

When you drag a subsystem, masked or unmasked, onto the list of components or the Switch Loss Calculator block, PLECS descends into the subsystem and adds all supported switch components that the subsystem contains.

Operating Principle

The internal calculations of the Switch Loss Calculator are illustrated by the equivalent schematic in Fig. 143. The example uses two switch components, for which all loss signal types are calculated.

../../_images/switchlosscalculator_equivalent_scheme.svg — Fig. 143 Switch Loss Calculator equivalent schematic

Equivalent schematic of the Switch Loss Calculator block.

Parameters

Averaging time: A scalar specifying the period or a two-element vector specifying the period and offset of the averaging interval, in seconds \((\mathrm{s})\). See also the Discrete-Periodic sample time type in section Sample Times.