FREQUENZUMRICHTER MIT GLEICHSPANNUNGS-ZWISCHENKREIS

摘要

A frequency converter with a d.c. voltage intermediate circuit consists of a power circuit, a control circuit which controls the elements of the power circuit and receives signals from the power circuit, and one or more user interfaces through which the control circuit receives commands and data and sends messages and data. The aim is to reduce the design voltage for the insulation to a minimum. To this end, a reference potential of the control circuit is applied to the midpoint of the intermediate circuit voltage, the control circuit is designed with a microcomputer with a user interface in the form of digital, insulated data connections, and the user interface is insulated with a design voltage at least from the intermediate circuit voltage.