Servo drives are an integral part of a servo system. Working in tandem with a motor, controller,
and a feedback device, servo drives receive instructions from the controller
for the prescribed motion for the motor. It then sends the right amount of
electrical current to enable the motor to perform the motion required.
There are several types of servo drives including those that
control torque as well as velocity and positioning. But torque is the most used variable in many
servo systems. Because they deliver the
precise required voltage and current to motors, servo drives are also called
amplifiers.
All variables encountered by service systems – torque,
position, velocity – are part of a complex motion control system that impacts
safety, efficiency, and equipment condition.
So, having the right servo system components are critical. Without the right components, servo systems
could overheat and shorten the lifespan of the motor.
There are many OEM producers of servo drives across the
globe. Many produce interchangeable
components while others have drives tailored for specific applications. Here is a look at the top ten manufacturers
of servo drives within the industrial automation space.
Allen Bradley
With more than a hundred years of history that electronics,
controls and motion systems, Allen Bradley offers a wide range of PLCs, HMIs,
sensors, safety systems and servo systems as well as software to give system
designers safe, reliable products for almost any application.
Allen Bradley’s servo system is part of a family of products
offering integrated safety and superior flexibility for standalone, medium and
large motion systems. Their servo drive
line is sold under the Kinetix brand and allow integrated motion working in
tandem with Logix based controllers.
They offer drives utilizing EtherNet/IP and others which are capable of
operating on a SERCOS interface and. The
flexibility of the Kinetix line covers power needs in the low, medium and high-end
range.
Allen Bradley’s EtherNet IP Drives come in models 5500, 5700,
and 6500 and can work on any system utilizing EtherNet IP. Their SERCOS
Interface Models are offered as the 6000 and 6200 are designed for low and high-power
applications and are ideal for integration with their food-grade motors. Finally, for standalone and low power
applications the Kinetix 5100, 3 Single-Axis Component, and the Kinetix 300
offer low power and single product flexibility for designers and builders.
Siemens
Another company with century long history, Siemens has leveraged
its early production of computers and semiconductors beginning in 1945 to
produce a wide range of products from windmill technology to transportation
system electronics. Beginning in 1958,
Siemens began producing PLCs under their Simatic name brand which grew to a
large family of control and automation systems today.
Today, Siemens offers servo drives under their SINAMICS brand
for a wide range of drive applications in the low and medium voltage DC
range. Siemens offers standard performance
models such as the V20 which works up to 30kW through the G150/150 which
operates as high as 2700 kw. This
standard performance line also offers two mid-range sizes in the G120 and G120C
at 250 and 125 kW, respectively.
Siemens also produces industry specific drives in the G120X
and G180 for complex systems requiring a wide range of communication and
operating frames and with special safety applications. Industry applications include conveyance,
processing, pumps, and compressors applications.
For low voltage applications, they offer the energy efficient
S120 and S120CM. They offer highly
scalable and flexible modularity that can be integrated with a host of other
components. They also offer a wide range
of communication protocols.
SINAMICS high performance drives include the modular S150
which can recover energy from the system and improve energy efficiency. This modular system can be used in larger
control systems and a variety of communication protocols. For simpler and more cost efficient yet
high-performance needs, the SINAMICS DCM is compact, yet delivers high power
ratings when needed.
Schneider Electric
Rising from an armament’s manufacturer in the early 1800s to
a provider of motion and control solutions today, Schneider Electric began
focusing on electrical components exclusively in 1981. Through a series of key acquisitions of
brands such as Square D and Merten, Schneider has grown to provide real-time
automation and has invested heavily in developing its automation products and
software.
Schneider’s Lexium family is separated by power and
functionality into several groups. The
Lexium 32, 23 Plus and 28 models offer a wide range of variants in both single
and three phase drives. The Lexium 32 is
rated up to 11kW while the 23 is rated at 7.5 kW max and the 28 at 4.5 kW.
The Lexium 52 is a standalone drive controlled by Schneider’s
PacDrive LMC controller family. They
have a high-power density and work well for single axis applications that are self-contained. They can work in industry specific
environments with Schneider’s stainless steel motor line for industries
requiring economical yet scalable automation.
The Lexium 62 is a modular multi-axis drive that uses up to
50% less cabinet space than comparable models.
This reduces cabling and mounting costs.
The 62 works with PacDrive controllers and comes in safe versions as
well that allow management via SERCOS interface.
Omron
Originally formed in Japan prior to WWII, Omron has become a
leading manufacturer and developer of advanced sensor, control and automation
systems. Their current Sysmac automation
system allows integration by servo components into a single platform.
Omron servo drives are offered in Omron’s G5 series. Their drive models are categorized by power
application which includes:
- Single-phase
120V AC – 4 models
- Single-phase
230V AC – 9 models
- Three-phase
230V AC – 10 models
- Three-phase
480 V AC – 23 models
Omron servo drives come in EtherCat, ML-II, and Analog/Pulse
versions. All models have an encoder
built in and operate with advanced tuning options via algorithm for vibration,
anti-torque and disturbance. All models
have advanced functionality that includes load inertia detection, dynamic
braking and regeneration, and overtravel protection.
Emerson/GE
For many decades, General Electric provided automation
solutions under the GE Intelligent Platforms and GE Automation control
products. But in 2019, Emerson purchased
the Intelligent Platform unit from GE and now functions as Emerson Automated
Solutions. Since acquiring GE’s
Intelligent Platforms, Emerson offers complete servo system products under its
PACMotion brand.
All of Emerson’s PACMotion servo drives can be matched with
servo motors via a plug-and-play configuration.
PACMotion servo drives are low profile and compact and all operate with
EtherCat controllers but can be utilized with third party components. Each drive is capable of closed-loop control
of speed, torque and position.
Emerson PACMotion servo drives come in 8 models ranging from
1100W…16,000W. There are four models
each rated for 120/240V AC and 240/480V AC.
Multiple drives can be added to the system to scale for larger system
builds with up to 50 coordinated control axes and all come standard with Safe
Torque Off.
ABB
Another older player in the automation market is ABB. Founded in the 1800s as an electric company,
ABB has progressed through numerous acquisitions to become a leader in robotics
and motion control. Starting in 2010,
ABB began to move heavily into motion control with additional acquisitions and
motion continues to exist alongside robotics, power generation and power grid
technology.
ABB has a wide range of drive sizes, frames and power ratings
depending on application. They produce
low voltage AC drives for systems up to 7500 HP as well as DC drives for heavy
industries such as metal, mining food and beverage, and others. ABB’s DC drives have the greatest
power-to-size ration available with power ratings as high as 24000 kW. They also offer micro drives for low power,
standalone applications.
Depending on the application and required power, ABB servo
drives include:
- Micro
Drives – 3 models
- Machinery
Drives – 2 models
- General
Purpose Drives – 2 models
- Industrial
Drives – 3 models
ABB’s drive selection is geared toward covering any
need. While the larger industrial drives
and micro drives service power specific needs, other models are aimed at
customized or special requirements. For
example, ABB machinery drives can be custom configured for industry specific
requirements, making them easy for those industries to integrate them into
their control systems. ABB also offers
general purpose drives for a cost-effective and plug-and-play application with
less stringent, lower power or standalone needs with less features required.
Mitsubishi Electric
Long known as an auto maker, Mitsubishi also operates a
control and automation division providing control solutions for a variety of
industries. These systems are sold under
the MELSERVO name and are used in industries such as automotive, material
handling, food and beverage, and other industries.
The Mitsubishi MELSERVO line has a smaller number of options
compared to other manufacturers.
However, all offer EtherNet-based optical communication to keep system
components in sync and in real-time
The smallest member of the MELSERVO drive family is the
MR-J4-GF. This drive communicates with a
CC-Link IE Field Network. It can be
sourced in 100V AC, 200V AC, and 400V AC offers closed-loop control on speed,
torque, and position. It offers precise
positioning with built-in point table functionality.
Because of Mitsubishi’s focus on industry automation, there
are 3 models the MR-J4-B, MR-J4W2-B, and MR-J4W3-B are used in 2 and 3 axis
applications. They communicate via the
SSCNET III/H and can use high-speed serial communication between the drive and
the controller. They are also available in 100V AC, 200V AC, and 400V AC.
For general purpose applications, Mitsubishi offers the
MR-J4-A. This drive uses pulse train and
analog as its inputs and can come in one functionality of speed, torque or
position. They are available in 100V AC,
200V AC, and 400V AC and support Modbus RTU.
The MELSERVO drive family also offers a micro drive in the
MR-J4W2-0303B6 and MR-J4-03A6. These are
ultracompact drives and only come in 48V DC and 24V DC. They can only drive a
rotary servo motor and are limited in wattage to a max of 30W
Hitachi
Know in the 70s for their consumer electronics, Hitachi’s
focus is predominantly industrial control.
They offer both general purpose and extremely fast PLCs to cover a wide
range of control needs.
Offering only an AC drive, Hitachi’s brand for servo drives
is the AD series. The AD series consists
of 34 drive models. Unlike other
manufacturers, Hitachi AD series drives are more intricately linked with
specific motor configurations. While
there are a few drive parts numbers that work with more than one motor, the
balance is specifically rated for a specific motor size.
AD series drives are smart enabled and can operate in a
standalone capacity. In simple systems,
they can even operate independent of a PLC if required. The entire AD series
line is a compact drive, limiting scalability.
However, what the AD series drive lacks in size and scalability is made
up in ease of use and can be configured via a Windows based PC to configure
position, sped, and torque.
Idec
Another post war manufacturer, Idec began making
electromechanical controls in 1945. Idec
has positioned itself in recent years to accommodate the IoT wave currently
exploding with increased automation and digitization. Many of its products, including servo systems
and servo drives, are specifically designed to address this and it allows its
devices to be accessed via a conventional browser.
Idec relies heavily on EtherNet communication with its
MicroSmart Pentha PLC line for remote machine monitoring. This is reflected in its servo drive
offerings which, unlike other drive makers, combines the PLC and drive into a
single unit.
This has several advantages.
It means the drive can be ultra-compact and used for standalone as well
as large systems. It is also flexible in
that it can operate from 1 to 6 axes with a “buy what you need” offering. The unit operates in both open and closed
loop and is easily programmed through a PC.
However, there are currently only two models available, and
it is unclear whether the system can be scaled to accommodate heavier industry
as is. It may be necessary to separate
the combined controller/drive functionality for larger builds and heavier
industries to build out a more versatile and flexible response to industries
moving into IoT.
Keyence
Keyence specializes in industrial automation and
control. Under its KV-X Motion system,
Keyence offers a host of automation and control product. Their products are used across single and multi-axis
control systems and they are highly focused on precision and
high-performance. In fact, when a
multiple number of servo units are synchronized, the system can operate up to
112 axes.
The KV-X Motion system uses parameter-based programming to
allow for easy programming of components.
Units are ML-II compatible and can be mounted standalone or side by
side. There are fifteen models of servo
drive within the Keyence KV-X Motion system.
They range in power capacity from as low as 50W to as high as 50
kW. This makes t Keyence products a good
small to mid-range drive for systems requiring high precision and performance.
Despite the wide capacity range among models, all have the same feature sets embedded. From I/O to feedback to communication, all models have the same capabilities. This gives system designers the flexibility and agility to build systems to exactly the power needed without sacrificing features or overpowering a build. The only exception to this is power supply with ten models at three-phase 200V and 5 models offered at single phase 200V AC.
