Rather than breaking down the drivetrain into different sections and focussing on a single component, such as the motor, Bauer believes that a view should be taken of a single, ‘electro-mechanical’ package – one which must be fully integrated to achieve maximum performance. Despite the current focus on motor efficiency, the potential energy savings throughout the drivetrain can typically be distributed via the ZVEI model which is:
• 10% via improved efficiency of the motor,
• 30% via electronic speed regulation,
• 60% via optimisation of the mechanical system.
As the model shows, while it is motors that are currently grabbing the headlines for development, there is no point specifying the latest motor if the foundations are not already in order.
Using a speed control device to monitor and regulate a motor will straightaway make a significant improvement to any application that doesn’t require the motor to operate at full load at all times. Even when operating at full load, a motor with a variable speed drive installed will still be more efficient at start-up. The importance of speed control in real world efficiency is recognised by the introduction of Regulation 640/2009. This stipulates that from January 1st, 2015, any installation in Europe where an IE2 rated motor between 7.5 kW and 375 kW is specified, it must be installed with a variable frequency drive (VFD).