A new Design Guide from Techdrives helps machine designers and specifiers to reduce the running costs of their machines. This substantial document of 30 pages and more than 7000 words focusses on energy saving in the drive train; that is the motors, drives and gearboxes. With more than 33 per cent of the generated electricity across Europe being used by electric motors, the importance of energy saving is clear. For many machines the lifetime cost is dominated by the cost of the electrical energy consumed. Designers need to promote their machines with details of the running costs and particularly the energy consumption. Incorporating energy-saving technology can give manufacturers a competitive edge in the market for their machines.
The Techdrives Design Guide begins by looking at electric motors with the current EU regulations, the changes in 2015 and 2017 and then some predictions for further changes that will happen from 2018 to 2022. Other types of motor are discussed that are currently outside the scope of the regulations but nevertheless offer significant saving potential. Selection of an efficient gearbox attached to the electric motor can yield significantly greater savings, in extreme cases by as much as 50 per cent. The Design Guide covers this area and gives designers guidance on what to look for.
Further big reductions in energy costs are made possible by the use of variable-speed drives. This is very much application-dependant, but savings of 30–50 per cent are often possible. The options here are described in four areas:
- Adjusting the motor speed to match demand
- Optimising the speed/position travel profiles
- 'eco' software to reduce motor currents under partial loads
- Re-use of braking energy (regenerative braking)
The final section of the Design Guide looks at the savings that result from accurate dimensioning of the drive. Generally there is a tendency for designers to play safe and go up a size due to uncertainty in the application requirements. Dimensioning software that aids the selection process is now available and proven to be highly accurate. It is particularly effective with machines that have multiple drive axes and field experience indicates that energy savings of 10–35 per cent are usually possible. The software will also generate an Energy Certificate that details the electrical energy running costs of the machine for a year.
The new Design Guide is available as a free download from the Techdrives website: www.techdrives.co.uk/energysavingdesignguide.html. It is bookmarked and easy to read, with the minimum of jargon. Machine designers and specifiers in the UK can also request a free paper copy by post.