High-Powder Ethernet-Compatible Three-Phase AC Motor Drives

[Baldor]() has extended its range of three-phase AC motor drives compatible with the Ethernet-compatible Powerlink protocol, adding three higher power versions rated for continuous outputs from 21.5 to 33.5A. The new drives extend the significant system building advantages of Powerlink to a much wider range of continuous and heavy-duty applications, including printing, papermaking, converting, textiles, plastics and steel production.

Called MotiFlex e100, the three-phase AC drive range now offers eight choices of power output from 1.5 to 33.5A. For many of the applications targeted by this product release, the higher power versions will provide the means to bring large AC induction motors into the Ethernet Powerlink control network, such as those used on the main axes of web processes.

"Baldor now has the broadest range of Powerlink compatible single- and three phase drives in the industry, giving a majority of industrial system builders the platform to redesign their machinery," says Baldor’s David Greensmith. "Powerlink offers a very versatile control platform that can improve performance substantially, while simultaneously simplifying the control architecture and reducing costs."

In addition to introducing the flexibility of high-speed Ethernet and TCP/IP connectivity into the higher power machine building sector, the drives’ high degree of modularity, combined with novel design features, provides users with significant potential for saving costs.

MotiFlex e100 drives can be used in both centralized control and distributed ‘intelligent drive’ scenarios for example, in both cases with substantial savings in the electrical power components typically required.

Compatibility with the Ethernet Powerlink protocol introduces great flexibility into electrical system building. Each drive features an Ethernet hub enabling systems to be built using a simple daisy-chain connection scheme. The high-speed and deterministic Ethernet Powerlink network, operating at 100 Mbits/sec, cuts cabling substantially, and can greatly reduce the costs of building large multi-axis systems. For example, a single Baldor Ethernet Powerlink machine controller can manage systems up to 16 interpolated axes.

In terms of core performance as an AC drive, a Baldor development team has been working for over three years on MotiFlex. The resulting design incorporates a large range of features that serve to liberate high power machinery builders to make savings and improve machine performance.

Each MotiFlex drive can operate independently, or as part of a shared DC bus system. When operating in a shared DC bus system, power regenerated back into any drive during the deceleration phase of an axis may be utilized by the other axes, saving energy costs. As each drive has a local capacitor bank, an external braking resistor is often not required – because the total capacitance of the system may be sufficient to store the energy without reaching the over-voltage limit.

Unlike traditional shared DC bus systems, Motiflex drive systems do not require a separate power supply unit. Instead, the AC-DC converter stage in each drive is capable of supplying power not only to itself, but also to a drive or combination of drives of the same total rating. For many multi-axis applications, this will often mean that the highest-rated drive will be able to power the rest of the system.

For many multi-axis systems, this approach almost invariably results in the need for fewer electrical components, and simpler system building, as only one set of contactors, fuses or MCBs, terminal blocks, and one EMC filter is needed for the whole system. Alternative approaches on the market today can require the same AC components for each drive, or the addition of separate power supplies and capacitor banks with fixed ratings that often mean they may be oversized for the application in question.

The drive’s control electronics can draw power from the main AC-DC power supply, or from a 24 VDC linking system on the front panel. Using the 24 VDC supply ensures that the control and communications status are maintained if the system is used in an application subject to safety shut downs, where the mains supply is disconnected.

Configuration flexibility has been at the core of the design requirements. Each drive incorporates a universal encoder input (incremental encoder, EnDat, SSI, sincos, multi-turn and single-turn) and built-in I/O (three digital inputs, two digital outputs, a +/-10V analogue input, brake control output, plus CANopen and USB ports). A further two ‘option card’ slots provide an expansion capability that allows users to precisely configure the local attributes of the drive, and/or provide an upgrade path. The choice of expansion options includes analogue and digital I/O, resolver feedback, encoder feedback, and fieldbus interfaces including Profibus, Modbus and Devicenet. The CANopen interface and the fieldbus expansion option provide great flexibility to employ the drive as a gateway for interfacing with other machine control systems such as PLCs.

A further unique expansion option for the drive is a plug-in machine controller compatible with Baldor’s Mint motion language. This option allows a MotiFlex e100 to be used as a standalone ‘intelligent drive’, providing a distributed motion solution that can cut hardware costs dramatically. This low-cost Mint card is also Ethernet Powerlink compatible, and will control up to three further daisychained MotiFlex e100 drives, providing a low-cost automation solution for many common multi-axis requirements. If more axes are required, Baldor’s panel-mounting NextMove e100 controller provides a solution.

One additional feature of the drive’s configuration flexibility stems from tools provided with the drive, in Baldor’s configuration software, Mint Workbench. Options include configuration wizards, auto-tuning software, and anti-resonance filters that may be used for both rotary and linear servo and vector motors.

The Mint language has been developed over nearly 20 years and today offers a high-productivity development environment for automation applications. Its use of high-level English like commands simplifies program writing and comprehension. These commands include probably the richest motion control programming facilities available worldwide, with ‘keywords’ that effectively provide templates or ‘canned’ software functions for common motion/movement related functions. The incredible range of Mint’s motion control functions compared with ‘open’ industry software – greatly simplifies complex machine design projects. The software also comes with its own license-free multi-tasking operating system and free Active X components for easy connectivity with PCs.

The new drives complete Baldor’s range of Ethernet Powerlink products for motion control. Developers can now choose from a portfolio that includes single-phase and three-phase drives, a panel-mounting machine controller suitable for large multi-axis systems and machinery, and a low-cost plug-in board for ‘intelligent drive’ and simpler applications, plus both linear and rotary servo motors. Many more compatible machine control system components and accessories are available from other Ethernet Powerlink suppliers, providing an advanced and highly economic platform for machine design.

Related Articles