Drive system is complete solutions platform

Control Techniques reckons it has created a new benchmark for AC drive performance and flexibility with the launch of the Unidrive SP drive system.

Control Techniques reckons it has created a new benchmark for AC drive performance and flexibility with the launch of the Unidrive SP drive system.

The Unidrive SP (solutions platform) marks the evolution of AC drives from dedicated controllers of speed and torque to fully-fledged solutions platforms in their own right.

It provides unequalled universal control and communication capabilities to handle the most complex centralised and distributed applications, as well as the versatility and simplicity of operation required for standalone applications.

"The Unidrive SP provides technical solutions combined with cost benefits that answer the demand of drive users, both today and tomorrow", says Phil Sewell, Executive Vice President Sales and Marketing for Control Techniques.

"And provides a challenge to drive users, who really should be benchmarking their existing products against the newest and most competitive drive technology available.

The challenge in essence is this: can you really afford to ignore new levels of drive performance and functionality, plus the savings in equipment costs and panel space that our new solutions platform can deliver?".

Unidrive SP is a true motor processor catering for all motor requirements, enabling drive users to standardise on one product for all types of drive control with the commensurate benefits of savings on equipment costs, inventory, training and maintenance requirements.

The drive is so flexible it provides a wealth of integration possibilities and the facility to be customised to suit particular applications, lowering total system costs whilst improving productivity.

What makes the Unidrive SP design so uniquely configurable is the number of features that combine to produce the overall "solutions platform".

Principal among these are: universal drive selection - the Unidrive SP can perform V/f, open and closed loop vector, servo and regeneration operation; universal feedback - Unidrive SP can be configured for 14 different feedback signal devices as standard; and Unidrive SP's facility of onboard solutions modules (SMs) that tailor the drive both in terms of scalable control (ie in replacing a PLC) and in terms of communications, with a wide choice of fieldbus options available.

The facility for universal drive selection was a revolutionary step pioneered and perfected by Control Techniques some six years ago.

The unprecedented flexibility of operation and undoubted cost savings that it has brought to users over that period, formed one of the cornerstones for the new thinking that has resulted in Unidrive SP.

The success of the "universal concept" in one area of the Unidrive SP design led to its employment in another: feedback encoder devices.

The Unidrive SP is the first drive in which users do not have to worry about what type of encoder they are using.

Nor, having ascertained encoder type, do they have the cost of extra cards or the time or space taken to fit them into the drive.

Instead, in a new design, the Unidrive SP provides software selection for up to 14 types of feedback signal devices as standard, including quadrature/pulse encoders, SinCos encoders, frequency and direction commands EnDat, Hiperface, SSI absolute encoders and CW/CCW references.

In addition, Unidrive SP offers the provision via the "clip-in" SM-Resolver module for resolver feedback, and the facility for a second universal encoder via the "clip-in" SM-Universal Encoder Plus module.

This option, in addition to duplicating the choice of 14 types of input, provides an identical choice of outputs.

These outputs can be sourced from any drive parameter, enabling virtual master systems to be implemented.

Encoder feedback modules are just one part of the comprehensive SM module range, which also contains extended I/O modules, applications modules that provide graduated or scalable levels of PLC control, and fieldbus interface modules.

In total, a quantity of three modules of any type or mix (including fieldbus) can be accommodated on the Unidrive SP at any one time, providing OEMs with a unique facility to customise and scale their control systems to meet "cost-down" budgets.

As an example of this: in centralised systems and a mix of centralised and decentralised systems the SM-Applications modules provide a zero space and scalable IEC61131-3 based control option that can either replace a PLC or reduce the load on central PLC or PCs and thus avoid the cost of additional processing power.

At the same time, other SM modules mounted on the same drive can be providing multiple communication options via unique fieldbus-to-fieldbus gateways (for Profibus-DP, DeviceNet, CANopen, Modbus RTU, Interbus and CTNet) that eliminate costly interfaces when more than one fieldbus type is required.

In distributed control systems the SM modules enable the costs of primary system controllers to be avoided altogether, providing cost effective PLC and motion control in the drive.

Up to three SM applications modules clip neatly into the Unidrive SP, providing a low cost facility for drives system designers to write application specific programs in an IEC61131-3 program environment and achieve peer-to-peer real time control at high speed.

In distributed control applications drive-to-drive synchronisation for multi-axis co-ordination is achieved via Control Techniques dedicated high-speed (up to 5Mbit/s) fieldbus, CTNet.

However, in these systems too, Control Techniques' unique SM gateway technology ensures compatibility and ease of interface between different fieldbus types.

Further enhancing Unidrive SP's credentials as a unique solutions platform are the drive's user interface versatility and it's Smartcard facility for simplified setup and maintenance.

Unlike most conventional drives, the Unidrive SP does not tie users into unwanted costs by providing an onboard programming keypad as standard.

Instead, the design specification offers a number of options, which reduce costs considerably, especially in multidrive applications.

These include an optional LED keypad that is "hot pluggable" for maintenance and commissioning, and an optional onboard remote mountable backlit LCD keypad, which offers online help functions, dual language and customer configuration text database facilities.

A third alternative is to program the drive via a PC using the Modbus RTU port on the front of the drive.

This port is "hot pluggable" (ie it requires no "power-down" to connect) enabling programming and interrogation of the drive itself, the Smartcard, the LCD keypad, the universal encoder setup and the SM applications modules.

In addition, when the application is CTNet based, the Modbus RTU port at the front of the drive enables users to view and access other drives on the network in a real time environment.

The Smartcard facility complements the functionality of Unidrive SP's "hot pluggable" commissioning tools, providing real benefits for OEMs.

A standard feature on a drive for the first time, Smartcard provides ultimate backup security to the user, plus flexibility in programming, system setup and maintenance.

It can clone a complete set of parameters for insertion into other drives in serial production; automatically save all user parameter changes for maintenance purposes; load complete motor map parameters; and be set up to save parameter differences from the default setting (macros) for future use.

In addition, advanced Smartcard software tools, including a desktop writer, enable programming of the Smartcard in an environment divorced from the drive itself.

The card is then simply inserted into the front of the Unidrive SP to provide the OEM with the flexibility of full "plug and play" facilities and also simplified startup.

The Smartcard, in keeping with the design ethos of the Unidrive SP solutions platform, is all about reducing overall cost to the drive user by including the maximum number of integrated features on the drive platform as standard.

That Control Techniques has succeeded in achieving this objective is ably demonstrated by the fact that the drive not only includes all universal control and feedback functions, but also its own onboard EMC filter and optional zero space braking resistor, 24V control supply input and 48V DC alternative power supply input and a unique secure disable (SD) function that enhances drive system safety at the same time as reducing component costs.

The integrated EMC filter meets all the requirements of EN61800-3.

It is one part of an integrated EMC package for the Unidrive SP, which includes a practical cable management package with more efficient facilities for power and control screen bonding that enable best practice wiring and ease of installation.

In the same way that the integrated EMC filter provides a reduction in overall system components.

The lower voltage 24V control supply input is included to maintain power to control, fieldbus and encoder modules during commissioning or power failure with the mains supply disconnected.

Its function is extended by the 48V backup power supply input for safer machine set-up and to provide a reduced speed operation backup in lift rescue applications or where material needs to be purged from machinery.

As a major solutions platform Unidrive SP has had to address not only all areas of control and communication but also safety.

Invariably in modern control systems, some means has to be provided of preventing a drive from generating torque in a motor with a very high degree of integrity when the drive is in standby or stop mode.

In most conventional systems this requirement is fulfilled by safety contactors, which are additional components and therefore add cost and increase space required in the cubicle.

Unidrive SP overcomes this problem with its own integrated secure disbable (SD) function.

SD is suitable for incorporation into the safety system of a machine.

It is also independent of the drive firmware; as such it meets the requirements of EN954-1 category 3 required for EC Machinery Directive.

The Unidrive SP range is dual rated and can operate in both normal and heavy-duty regions and is available in the power range from 0.75 to 30kW.

In addition to its many system features the range offers the OEM true worldwide operation with an input voltage range from 200 to 690V AC, 50/60Hz.

In control terms the drives offer market leading motor shaft performance and torque loop update times and ultra quiet and efficient operation with a switching frequency up to 16kHz.

Phil Sewell adds: "The new product design cycle is done typically to gain 2-4 years advance on your rivals, and in so doing to leapfrog forward.

When you start from the leading pack as we have with Unidrive, the leap forward is more pronounced, with the process more akin to evolution than radical revolution, and the result is more effective hence the benchmark".

"Control Techniques have once again taken a giant leap forward in design concept and technology, placing us a product generation ahead of other drives manufacturers".

(This was Engineeringtalk's Top Story on 15 October 2002).

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