Minimise panel space on high axis count servo applications

Nidec’s acquisition of Control Techniques from Emerson has breathed new life into the British drives specialist, not least with huge investment in the company. One of the first results of that investment is the new Unidrive M750 servo drive – a project that was started under the Emerson ownership but hugely accelerated once Nidec took control of the Newtown based drives company.

The new servo drives are focused on high overload, pulse duty applications, but also provide continuous servo control, plus induction motor control. The 400V drive targets high axis count automation systems, providing all the benefits of a modular system with a common DC bus, with standalone drive flexibility.

The drive contains numerous innovations, but perhaps the most striking feature is its size. “We conducted extensive market research to find out what was most important to drives users,” says marketing communications manager Alex Byles. “And what came out as most important was size.  Cabinet real estate is expensive, so machine builders want to be able to keep panels as small as possible.”

With this in mind, Control Techniques developed a form factor for the M750 series which is just 40mm wide. This potentially could give you five axes of motion in space less than the width of an A4 sheet of paper.

“As well as width, depth was also highlighted as being important,” says Byles. “Often the deepest product in a cabinet is the drive, and so that defines the minimum size of the panel. So we set out to design a servo drive that could be installed in a shallow 200mm deep panel.” The design also minimises the height of the drive, and enables machine builders to really shrink the size of the panel. And that downsizing of panels is further supported by the patented Ultraflow cooling technology employed in the M750.

With Ultraflow, air is sucked in through the bottom of the drive and expels heat directly outside the cabinet. Control Techniques says this approach is much more efficient and has the additional benefit that drives can be stacked without the need for a large air channel between them. The end result, says the company,  is that machine builders can further reduce cabinet size by 50%.

None of this comes at the expense of performance. High dynamic applications will benefit immensely from the M750’s 300% peak performance pulse-duty overload capabilities, along with its 62µs current loop and 16kHz switching frequency. Its flexible speed and position feedback interface supports a wide range of feedback technologies, from robust resolvers to the latest single cable digital encoder technologies.

It also offers a wealth of features and accessories designed to make installation and commissioning as easy as possible. Features include easy-access pluggable connectors and a dedicated multi-axis paralleling kit for rapid installation; integrated braking resistor and electronic motor name plate for faster setup; and quick commissioning using the Unidrive M Connect PC tool, or an optional SD card. Machine Control Studio provides a flexible and intuitive IEC61131 environment for programming automation and motion control features.

“For ease of installation, all of the motor connections on the drives come in at the same point, regardless of the size of drive,” says Byles.

The M750 will initially be offered in two configurations; the M751 and M753. The M751 Base option allows machine builders to add up to two option modules from the existing Unidrive M range such as Profinet, Ethernet/IP or an IEC61131 high performance motion controller for decentralised machine control. The M753 is designed as an optimised amplifier for high performance centralised control with EtherCAT integrated on-board and simple rotary switches for fast network address assignment.