Electromagnetic Compatibility (EMC) and Variable Speed Drives
Editor’s Note: Much of the information which follows is taken from engineering information provided by Siemens AG in their “Sinamics DCM Converter Units” catalog D 23.1 – 2010. The Sinamics DCM is the line of industrial DC drives in the Sinamics family, which forms a part of Siemens’ “Totally Integrated Automation” concept; learn more at www.siemens.com. However, the concepts discussed herein can generally be applied to any drive application.
Because of the high switching frequencies of their electronic components, variable speed drives are by their nature radiating devices. This radiated energy is termed electromagnetic interference (EMI); measures to reduce EMI during design and installation are intended to ensure electromagnetic compatibility (EMC), which is essentially the ability of a device to function satisfactorily in an electromagnetic environment without itself causing interference unacceptable to other devices in the environment.
In the typical industrial environment, EMI occurs in the range of 150kHz – 30 MHz and can have adverse consequences on the operation of nearby sensitive equipment. When considering measures to ensure EMC, the drive must be looked at as forming part of a system, the other components being minimally the cables and […]