ARC Advisory Group (www.arcweb.com) says small drives are getting so much capability that they will be able to replace smaller control systems used in industrial OEM machines. ARC predicts that low-power AC drives will grow at a rate of 4.7%, reaching $5.1 billion by 2007.
ARC also says the servo drives market will grow by nearly 7.8% to about $2.2 billion in 2003, and then increase by 10% in 2004. ARC says this growth will be driven largely by Japan. The North American market will remain relatively flat in 2003, and start to pick up in 2004.
Applications for servo drives include CNC, robotics, and general motion control, says ARC.
One reason for the success of high-power AC drives, says ARC, is their significant energy savings. When big AC drives are used for material handling, crane controls, building automation, and water and waste treatment, they use less energy than more traditional methods.
Following is a brief summary of what suppliers are offering these days in drives. We were surprised to see that only a few have added Ethernet connections. In fact, only a few drives even mention how you might communicate with them. Finding out how to talk to these new drives is a good excuse for calling the company. We've provided web addresses and phone numbers to help you with your search for the right drive product.
(Editor's Note: This is the third and final installment of our roundup of motors and drives.)
The SM3416 SmartMotor is a complete, compact, and integrated control system that features a brushless DC servo motor, motion controller, encoder and amplifier. It features multiaxis coordinated motion, network bus capabilities for RS-232, RS-485, DeviceNet, and ProfiBus, and has flexible on-board and expandable I/O. Position, velocity, and acceleration can be controlled to within 32 bits of resolution. Frame sizes range from standard NEMA 17 to NEMA 56 with speeds in excess of 10,000 rpm. Animatics; 408/748 8721; www.animatics.com
Fast Connections--Siemens E&A
Sinamics G110 is a compact, low power AC drive frequency inverter for variable-speed, three-phase motors on single-phase line power supplies. The inverter is rated for 200-240 V input with a power range of 1/6-4 hp. Available in three frame sizes, it offers mechanical/functional options that include space-saving flat-plate versions, serial and analog setpoint control, and features fast-connection terminals that allow installers to make connections without removing covers. Siemens Energy & Automation; 800/964-4114; www.sea.siemens.com
Stepper Motors Graduate--Copley Controls
StepNet stepper motor drives enable stepper motors to be included in CANopen networked systems that were previously limited to servo motor drives. StepNet drives operate under the DSP402 CANopen protocol for motion control devices. Embedded intelligence enables each drive to execute point-to-point moves with S-curve profiling. More complex profiles, defined by a series of position/ velocity/time points, are executed using polynomial interpolation for best-fit contouring. StepNet drives deliver 5 A continuous and 7 A peak current and operate from 20-75 VDC. Copley Controls; 781/828-8090; www.copleycontrols.com
Custom Panels for AFD--Danfoss
Enclosed drive panels for VLT 2800, 4000 VT, and 5000 Series adjustable-frequency drives are available with fused disconnect, two-contactor, and three-contactor bypass configurations. Drives can be ordered with a wide variety of options, including line or motor filters, meters, indicator lights, control switches, and NEMA 4, 4X, and 3R enclosures with heating or cooling. Danfoss; 800/432-6367; www.namc.danfoss.com
Drives Offer HVAC Functions--Eaton Electrical
HV9000 Series drives communicate via LonWorks and Modbus RTU, and even have functions for HVAC applications including smoke purge, PW setback, and PI control. Drives are available 1-1,000 hp, and 208, 230, 480, and 575 V. Preset software options reduce setup time and ease programming for applications such as pump and fluid control. Eaton Electrical; 800/356-1243; www.cutler-hammer.eaton.com
Fluent VFD--Bosch Rexroth
The 500 Series drive has SERCOS, Profibus, Interbus, SynchroLink, and CANopen interfaces. Drives are available with output ratings from 2-850 hp, meet class A standards for compatibility, and have speed control, torque, and speed regulation functions. Function blocks available include PID controllers, math blocks, digital gates, timers, and application-specific blocks. Guided commissioning via the control panel and the REFUwin software tool simplify startup and operation. Bosch Rexroth; 847/645-3712; www.boschrexroth-us.com
Has Good Brakes--Mitsubishi Electric
The V500 series AC vector drive has built-in brake transistor up to 20 hp, customer-selectable 5, 12, or 24-V encoder power supplies, and automatic gain tuning, which eliminates the task of manually tuning the drive and motor to the application. The drive is available in 240 VAC and 480 VAC from 1-75 hp. Mitsubishi Electric Automation; 847/ 478-2419; www.meau.com
Digital Drive Does Velocity--Advanced Motion Controls
DR100 Series digital drive for rotary or linear brush-type or brushless motors has a velocity loop that is implemented as a fully decoupled PID algorithm, with feedforward gain and 100-ƒsec update rate. All gains can be adjusted and system response monitored using free setup and configuration software. A configurable low-pass filter smoothes the velocity feedback, which can be derived from encoder or resolver signals. Models are available with current output of 15-100 A. Advanced Motion Controls; 805/389-1935; www.a-m-c.com
It's That Basic--AC Technology
The Ssi BASIC-language programmable servo drive with indexing and motion profiling capability has execution speeds equivalent to compiled languages in sophisticated motion controllers. It includes 4,000 lines of program memory, is able to define variables, and can perform math and logic operations, camming and splining, and on-the-fly gear and index changes. AC Technology; 800/217-9100; www.actechdrives.com