Distributed system approaches are increasingly seen as the way ahead in many manufacturing applications by providing greater operational flexibility. Installation and maintenance costs can also be significantly reduced by bringing control systems closer to machinery on the factory floor rather than following traditional centralised arrangements.
SEW-Eurodrive Victorian sales and product manager, Darren Klonowski, says frequency inverters with appropriate IP rating and mounting arrangements can be directly installed on an individual machine or production element, then networked together and overseen by a supervisory controller managing the entire shop-floor operation.
“Such a distributed control sys tem can improve reaction time to production events and result in significant efficiency benefits and overall cost savings,” Klonowski said.
“SEW-Eurodrive recently released the innovative Movigear ‘B’ all-in-one dece tralised mechatronic drive system that comprises motor, gear-unit and drive electronics in a single compact housing. Four communication variant options are available which allows users the flexibility to implement decentralised drive applications across a range of installation and communication topologies.
“Energy cost savings as high as 30 to 40% compared to traditional solutions can be expected due to the use of permanent magnet motor and optimised interface between control electronics and motor gear unit. The Movigear ‘B’ series is equipped with ‘Safe Torque Off’ integrated safety functionality as standard.
“Significant innovations have occurred in inverter technology in recent times including frequency inverters with built-in energy saving and various safety related functions.”
SEW-Eurodrive also recently launched the Movipro SDC ‘standard drive controller’, which is the company’s decentralised drive offering designed to provide industry with an easy-to-use field-mountable drive solution that is said to be ideal for single-axis closed-loop speed control and positioning of AC asynchronous and synchronous motors.
“Another major benefit is that the Movipro SDC does not require extensive and time consuming programming because operators need only parameterise the pre-configured application modules,” he explained.
“The foundation of SEW- Eurodrive’s decentralised prod uct range is the Movimot ‘D’, an ‘on-board’ motor-mounted fre quency inverter and geared motor combination.
“The Movimot ‘D’ combines the advantages of decentralised control with energy efficient motor technology.”
System focus
WEG Australia product manager automation, Sean Richardson, emphasises that significant benefits can be achieved by combin ing multiple products from the company’s range in order to get a ‘system benefit’ that is greater than the individual sum of the component parts.
“Optimal Flux technology asso ciated with our motors and drives in a system approach can provide energy savings and infra structure advantages through cooler running motors at low speed with full torque. Other benefits can also be gained from doing things like combining our drives and circuit breakers or soft starters and contactors with our motors,” Richardson told Manufacturers’ Monthly.
“The type and extent of benefits depends on the combination adopted in the system design approach. For example, Optimal Flux will provide advantages in terms of reduced installation and running costs by reducing the need for forced ventilation motors. On the other hand, if you were to combine our isolation contactor with our soft starter you would receive safety benefits. It’s all about identifying the objectives and then putting together the right combination to achieve a system benefit.
“Likely future directions include a continuing focus on system efficiency to reduce carbon footprint, and the develop ment of more compact products to utilise the prime real estate in electrical cabinet space. For example, our new CFW11 series of variable speed drives, that are rated to 720A, is about 60 per cent of the volumetric size of the older CFW09 that it is replacing. This reduction in physical size is due mainly to the advances in power electronics that give a huge advantage in panel and plant design.”
Richardson says that on the energy management front, the use of soft starters or variable speed drives will see advantages due to the reduced impact of motor locked rotor or overload current on the mains supply.
“If drives are used these ‘over load’ requirements can be reduced by values up to 530%, while with starters it could be as much as 270%,” he said.
“In addition, the use of drives with motors will allow the user of the system to run the motor at exactly the speed they desire. This means the system is only running to the demand of the system, and this is the most effi cient form of usage there is.”
Productivity benefits
According to Bonfiglioli Transmission Australia product manager automation, Steve Dumbrell, productivity benefits flowing from the latest product developments include easier setup and program duplication to other drives, power savings when drives are in standby, and the ability to run servo motors without resolver.
“Also, drive cooling is from bottom to top which allows drives to be mounted side-by-side, and height is the same across all three sizes which helps panel builders to save space in cabinets. Such developments will assist our manufacturing cus tomers to achieve significant cost savings,” Dumbrell said.
“In the future we are likely to see a bigger push to use servo motors over squirrel cage motors, as well as a move to one-drive- fits-all applications, and motor-mounted drives. An increasing trend to renewable energy and drives to power and convert this energy can be expected. Bonfiglioli currently supplies inverters to one of the world’s largest photovoltaic plants in Spain As environmental impacts increase and the cost of electrici ty rises we will see a greater requirement for drives to reduce power demands of direct on-line connections. Motors connected direct on-line can draw up to seve times full-load-current on start-up, but a drive will limit this to 150% and give you full torque of the motor across 100% of the motor’s speed range.
“The ability of a drive to vary the speed of a motor to suit the application can provide great cost savings in applications such as air conditioning. Running fans at lower than full-speed in the correct control method via a drive can create savings of 50- 60% over old damper control sys tems. In addition, motor heating is reduced and starts per hour can be increased with a drive.”
Latest product developments from Bonfiglioli include the Agile frequency drive with the 400v version released in July and the 200v due for launch at the end of this year. Dumbrell says the Agile comes with a plug-in memory card that allows the drive program to be backed-up and remotely-monitored via PC, while a diagnostic function con tinually monitors the drive for potential faults.
New motor technology
Baldor Electric has developed innovative low-speed permanent magnet motors that the company says can be used in direct-drive applications to eliminate the gearbox, three phase electric motor, driveshaft, and disc couplings from cooling tower designs.
According to managing director, Daniel Vera, interior permanent magnet motors can improve reliability and reduce maintenance of cooling tower installations as well as increase efficien cy and reduce energy consump tion. “Following significant improvements in permanent magnet materials, and as prices decrease, we can expect perma nent magnets to provide even more highly efficient rotating machines,” Vera said.
“We have also launched a new generation of smart drives for many common single-axis automation requirements. These Ethernet Powerlink-compatible drives feature Mint Lite, a new programming capability that is being fitted on all Baldor’s MicroFlex e100 and MotiFlex e100 single and three phase drive ranges. This programming capability enables standalone drives to operate with many common automation tasks including cutting or feeding to length, indexing axes, and simple pick and place motion.
“In relation to energy manage ment systems, using MEPS high- efficiency electric motors and variable-speed drives allows the motor speed to be matched to required load speeds and can enable large energy savings. The use of variable speed drives pro vides an improved power factor as well as greater system effi ciency. Energy management sys tems can communicate with vari able speed drives, ascertain how much energy is being consumed, and provide system feedback.”