The New EDrives Library: A Modular Tool for Engineering of Electric Drives

Abstract

Simulation is an indispensable tool for the engineering of systems containing electric drives. Depending on the design phase and the engineering task different levels of modeling details are required: proof of concept, investigation of energy and power consumption, design of control, etc. The new EDrives library provides three levels of abstraction for inverters: quasi static (neglecting electrical transients), averaging (neglecting switching effects) and switching-for serving different demands. The inverters can feed the machine models of the Modelica Standard Library: Modelica.Magnetic.FundamentalWave and the new Modelica.Magnetic.QuasiStatic.FundamentalWave. The EDrives library copes with arbitrary phase numbers and can be easily extended to develop new control algorithms. In this publication the structure of the library and the implemented control principles are presented. Furthermore, examples comparing the three different levels of abstraction are included.

Behavioral Modeling of DC/DC Converters in Self-Powered Sensor Systems with Modelica

“…After defining the input and output ports, the causality between them needs to be established. There are two possible approaches: (1) a forward definition (approach of energy availability), where the power into the converter is controlled which then results in a certain output [ 13 ] or, (2) a backward definition (approach of energy demand), where the output is controlled, which results in a certain power draw at the input of the converter [ 12 , 14 , 15 ].…”

“…Instead, the efficiency should be considered to be a function depending on at least one of the four port values. Unfortunately, other available models only offer to specify a constant value for the efficiency [ 12 ] or even assume an efficiency of 100% [ 13 , 14 ]. The next best approach is to provide a fit function [ 18 ] or a look-up-table [ 15 , 16 ] for the efficiency.…”

“…The commercial EDrives library [14] includes three inverter models (DC/AC converters) to provide power to electric drives. The EDrives.PowerConverters.Averaging model neglects switching effects.…”

“…Equation ( 13) describes the PI controller's transfer function. The output y PI is connected to the input conductivity G in (see Figure 2) by means of the start-stop logic according to (14). Here, a switched-off converter corresponds to G in = 0.…”