Sustainability: energy-effective products and systems
IT'S THE SUM THAT MAKES THE TOTAL. Energy sustainability: an increasingly interesting topic, due to both the increase in supply costs and the opportunities for those who install efficient solutions.
But what knowledge does the end user have for weighing up the possibilities in the automation sector?
It's true that intrinsically effective products (brushless motors, inverters for managing variable speed motors) are now the natural choice thanks to the ease of evaluating the savings generated by the use of new technologies, but the evaluation of system solutions for both the operating cycles and the choice of automation architecture is far more complex.
The use of simulation software for the axis operating cycles - with reference to the mechanical configuration of the axes - simplifies the sizing process: Bosch Rexroth's IndraSize tool provides the main data needed (average and peak power absorbed and regenerated) in order to evaluate optimisations at mechanical level and with regards the movement profile.
The choice of the hardware architecture offers various points for analysis, to be assessed on the basis of the specific application characteristics. A machine architecture involving numerous axes, some absorbing electricity and others regenerating it due to lengthy braking phases, must steer the choice towards a DC BUS system shared by all the drives.
The Rexroth range is completed with the standard regenerative power supply units (able to immediately return the regenerated electricity to the mains) and the new Smart Energy version, where the power supply unit can store any surplus of regenerated electricity and then re-use it during the next absorption phase, thereby optimising regeneration towards the mains with solutions that produce energy savings of up to 30% compared with the standard solution.
In the packing machines, the most interesting solution in terms of energy savings is Bosch Rexroth's cabinet-free model: the range of motors with on board drive - IndraDrive Mi - now includes remote-controlled power supply units (IP65 protection degree).
Electricity distribution on a single cable not only allows the sharing of just one DC BUS, but also fully eradicates thermal dissipation inside the electrical cabinets, often allowing the elimination of the air-conditioning system and the relative energy consumption and maintenance costs.
