Electromagnetic Compatibility of Electric Miniature Drives

Electric miniature drives are now present in a wide range of applications. In addition to classic mains-operated kitchen appliances, a wide variety of battery-operated devices with built-in electric motors are used in a domestic setting, from robotic vacuum cleaners through motor-operated heating valves to milk frothers. Electric miniature drives are somewhat less visible in daily use in optical devices, in laboratory automation or in special machinery construction.

For electronics developers, the challenge is to keep an eye on the components of the power electronics, microcontroller and sensor technology that come together in the controlled electrical drive in a very small space from the point of view of Electromagnetic Compatibility (EMC) and to find marketable compromises.

First, the book gives a brief overview of the development of the EMC topic and the current general boundary conditions for bringing electric drives onto the market. After this, the effects, coupling paths and test methods for both the emitted interference and the interference immunity are presented. The sources of the different disturbances originating from a motor controller are named and linked to their effects. On this basis, the common EMC measures are then discussed step by step, and their effectiveness verified by means of the measurement result.

This book is therefore aimed at users and supports them in setting up their end device in an EMC-compliant manner with a controlled miniature drive as a component. In addition, electronics developers learn the necessary basic measures to take EMC into account already in the development of motor controllers for miniature drives. If this is taken into account, such development projects can be successfully realised in an EMC-safe manner.

Topics from the book:

• Challenge of EMC: Interference sources in electric drives, frequency components, from radio interference suppression to EMC
• CE certification: EU directives for the operation of electric miniature drives
• Interference emissions of devices: Conducted interference, coupling paths for electromagnetic interference, measurement methods and typical measurement results
• Interference signals in controlled devices: Interference behaviour of a DC/DC converter, interference behaviour of a motor controller
• Limiting interference emissions: Propagation paths, grounding and shielding, cable routing, filter and test results
• Interference immunity of devices: Acceptance criteria, effects, measures
• EMC measures for miniature drives: Integrated motor controllers, externally mounted motor controller, encoders
• Additional measures to increase robustness: Coding, complementary signals (linedrivers), robustness of different interfaces