Efficient at each stage of production
Two thirds of the power consumptions in the industry are allotted to drives and motors. The energy’s saving potential is huge. According to different studies 30 per cent on average can be saved in this field. This article discovers the hidden and heaviest power loads and how to optimise them.
- Distribution of the industrial energy consumptions
Three main starting points for energy saving
July 12th, 2010 - There are three main starting points to reduce energy consumption of production processes resp. machines and systems:
- Optimal system design based on a mechatronic and global approach
- Use of high-efficient drives and motors
- Monitoring and analysis in order to identify and optimise the energy consumption.
Mechatronic and global approach
Energy efficiency already starts in the planning and construction phase. Right from the design stage suitable software permits a saving of power costs.
Up to 20 per cent of the energy can be saved only by optimised drive design. On top of this the simulation of the overall system during the design phase can optimise machine and drive as complete system.
Motors and drives - Electric Buffering
The energy exchange between motoring and generating operating drives resp. between drive and line implies a high energy saving potential. Only the DC link coupling of converters can save up to 50 per cent of the energy, compared with not coupled drives.
Apart from the regeneration of brake energy in the line there is also the possibility to store the energy, back-supplied by a drive, in a capacitor and to use it with the following acceleration processes. For this purpose the already existing intermediate circuit capacity can optionally be extended.
- Operating principle of the Kinetic Buffering
Motors and drives - Kinetic Buffering
A further alternative to save energy is the kinetic buffering. For this purpose a drive, additional to the coupled one in the intermediate circuit and equipped with a rotating masses, is used as intelligent kinetic energy buffer. The additional drive absorbs energy if there is an energy surplus in the system accelerating the rotating masses. If the system demands energy it delivers brake energy to the intermediate circuit.
Motors and drives - Distributed Configuration
With the use of modern distributed servo drives the energy exchange between motoring and generating operating drives is already integrated by the serial DC wiring. This additionally reduces the heat losses in the control cabinet and saves the air conditioners.
Central drives are substituted by distributed drives. That lowers the cabling costs by up to 85%, the control cabinet volume by up to 70%.
- Steffen Winkler, Head of Sales Industrial Sector Food, Packaging and Print at Bosch Rexroth AG
Monitoring and analysis tools
A special significance is related to the methods and technologies for identification, measurement and monitoring of the energy consumption. Only based on the knowledge of the system’s energy distribution targeted measures for optimisation can be executed.
For this purpose modern automation systems already offer a multiplicity of functions. So control system-integrated, software-based tools analyse cycle times and consumptions, e.g. drive-integrated energy monitoring can work as wear indicator of the mechanics at an early stage.