Drives and Controls Magazine
Servodrive system uses motors with built-in SiC devices
Published:  06 December, 2017

At the recent SPS IPC Drives show in Germany, Beckhoff unveiled a distributed servodrive system based on compact motors with built-in high-efficiency silicon carbide (SiC) power electronics – the first of their type, according to the company.

The low-power-loss SiC devices limit the derating needed for the servomotors to about 10%. By building the power electronics into the motors, the control cabinet only needs to house a coupling module to supply power to multiple servodrives, via single cables. The result, claims Beckhoff, is “significant” savings in terms of cost, space, materials and installation effort.

It adds that that the AMP8000 distributed servodrive system breaks new ground for modular machine concepts. Using the EtherCat P technology which combines EtherCat signals and power in one cable, one coupling module can control up to five distributed servodrives via an IP67-protected distribution module.

There are two coupling modules available to link the servodrives to Beckhoff’s AX8000 multi-axis servo system or Ax5000 EtherCat drives. These modules – available in single- or dual-channel versions – provide a DC link connection, a 24V DC power supply, and EtherCat communications.

The coupling modules are connected to the motors via distribution modules which each support to up to five motors. For larger installations, the single-cable connections can be cascaded via further distribution modules. The modules can be built into machines, reducing cable lengths and simplifying wiring.

The ability to cascade the system means that complex motion installations can be implemented with a simple topology. Preassembled cables are available that simplify the logistics further and minimise wiring errors. With fewer and smaller cable routes to the motors, installation efforts are said to be reduced “significantly”.

Beckhoff's distributed servomotors incorporate drive electronics using silicon carbide devices

Because the power module is located at the back end of the motor shaft, the new servodrives have the same attachment dimensions as Beckhoff’s standard AM8000 servomotors. The only dimensional change is to the motor length, which is about 7cm longer. For machine-builders, this means that only a little extra space is needed at the motor end, and the new motion control concept can be applied to existing machines, often without having to alter their designs.

The servodrives are available in flange sizes F4 and F5, in power ratings from 0.61–1.23kW and standstill torque ratings from 2–4.8Nm (for the F4 versions), or 1.02–1.78kW and 4.10–9.7Nm (for the F5). STO and SS1 safety functions are built in, and other safe motion functions are planned.

The distributed servodrive system is due to go on sale in the second quarter of 2018.