Allen Bradley PowerFlex Drives vs the Competition: Which is Best for Your Automation Application?

In the highly competitive world of industrial automation, selecting the most appropriate motion control solution for your application is critical. Variable Frequency Drives and DC drives are an integral part of modern industrial automation, providing precise control over motor speed and torque. These motion control solutions help improve energy efficiency, optimize process performance, and increase the service life of the equipment.

Allen-Bradley (Rockwell Automation), Danfoss, Delta Electronics, Fuji Electric, Mitsubishi Electric, ABB, and Siemens are some of the leading manufacturers of AC and DC drives. Each brand offers distinct motion control characteristics and capabilities geared to specific industrial automation applications. This article provides a technical comparison of the AC drives offered by some of the aforementioned manufacturers, with the aim of assisting users in identifying the best solution for their specific automation requirements.

Allen-Bradley PowerFlex Drives Overview

The Allen-Bradley PowerFlex drive series from Rockwell Automation offers a wide range of Variable Frequency Drives (AC drives) and DC drives designed to enhance system performance and energy efficiency in a vast array of industrial applications. Available Allen-Bradley PowerFlex drives are classified as follows:

• PowerFlex Low-Voltage VFDs: This is a flexible portfolio of PowerFlex AC drives that provide a diverse set of control modes, power ratings, features, communication & I/O options, and global voltages. The compact, low-voltage PowerFlex VFDs provide a low-cost, general-purpose solution for automation applications that require simple system integration and speed control. While the high-power and standard, low-voltage PowerFlex VFDs are ideal for automation applications that require torque, speed, and/or position control. These drives provide an application-specific variety of features.
• PowerFlex Medium Voltage VFDs: This category of Allen-Bradley drives features the PowerFlex 6000 and 7000 AC drive series, which are designed to provide reliable operation and high-precision torque and speed control. The two AC drive series are intended to meet a wide range of industry needs and configurations. They are ideal for special-purpose, constant torque, and all-purpose medium-voltage automation applications, from pumps and centrifugal fans to mills and conveyor belts. The PowerFlex 6000 VFDs feature the Allen-Bradley TotalFORCE motor control technology that helps increase productivity, throughput, and quality of end products with better motor control. These drives are specially designed for retrofit and new constant torque, variable torque, and high-speed automation applications up to 120 Hz. They are appropriate for pumps, compressors, fans, and conveyors requiring 2.3 to 11 kV motor control. The PowerFlex 7000 is a high-performance, liquid- or air-cooled VFD that includes power regeneration capabilities and provides variable-speed, soft starting, direction, stopping, and torque control for standard synchronous or asynchronous AC motors. They are offered in an extensive power range: 200 to 34,000 HP (150 to 25,350 kW) with input voltage ratings of 2.4 to 6.6 kV AC.
• PowerFlex DC Drives: The PowerFlex DC drives provide highly functional, cost-effective motion control solutions that can easily be configured for most industrial automation applications. They are intended for retrofits and DC motor automation applications rated up to 6000 HP or 4000 kW. These drives are available in both non-regenerative and regenerative configurations.

Key Features

• Smart Motor Control Technology: Allen-Bradley PowerFlex AC drives incorporate advanced motor control algorithms and real-time diagnostics for optimized performance, enhanced energy efficiency, precise motor control, and proactive maintenance.
• User-Friendly Interface: PowerFlex AC drives feature intuitive human interface modules with clear LCD displays and accessible parameters, simplifying drive programming, configuration, commissioning, daily operations, and troubleshooting.
• Integrated Safety Features: Most modern PowerFlex AC drives are available with embedded safety functions, such as Safe Speed Monitor (SSM) and Safe Torque Off (STO) — certified for SIL3/PLe CAT 3/4 safety-related applications. These integrated safety functions help reduce the need for external safety components, thereby simplifying system design.
• Auto-Tuning: The Autotune feature in some PowerFlex AC drives helps optimize the drive output and ensure dynamic performance by automatically adjusting the drive control parameters for specific motor-load conditions.

• Versatile Communication Options: Allen-Bradley PowerFlex VFDs support a wide array of communication protocols, including ControlNet, Ethernet/IP, Serial communications (like DH-485 and DH+), CANopen, Profibus, Remote I/O, and DeviceNet, among others. This allows seamless integration of the drives into diverse industrial networks.
• Flexible Mounting Options: PowerFlex AC drives are available with a variety of mounting options, including cabinet, DIN rail, and panel mounting, offering greater installation flexibility.

Ideal Applications

Allen-Bradley PowerFlex AC drives are appropriate for a variety of industrial automation applications, such as:

• Pumping Systems: In industrial sectors such as water and wastewater treatment plants, PowerFlex AC drives are instrumental in regulating pump operations. They adjust motor speeds to align with real-time loading conditions, leading to significant energy savings and optimized flow control.
• Fan and Blower Applications: Precise control of fans and blowers is critical for HVAC and industrial ventilation systems. PowerFlex VFDs are designed to provide high-precision control in such applications, ensuring efficient airflow management and reduced energy consumption.
• Material Handling: Conveyors are an integral part of material handling systems in manufacturing facilities and distribution centers. When used in conveyors, Allen-Bradley PowerFlex VFDs deliver accurate speed and torque control, enhancing the efficiency and reliability of material handling systems.
• Cranes and Hoists: Safety and precision are paramount in lifting applications such as hoists and cranes. Some PowerFlex AC drives, like the PowerFlex 7000 and PowerFlex 755T, are equipped with TorqProve technology — a control feature specifically designed to confirm load control by ensuring that the PowerFlex drive has control of the applied load before releasing the mechanical brake when executing a move command, and by confirming that the brake has control of the applied load when stopping the PowerFlex drive.
• Compressors: In industries that require compressed air or gases, such as petrochemicals, PowerFlex AC drives help optimize compressor performance by precisely adjusting motor speeds to match process requirements.

Danfoss Variable Frequency Drives Overview

The Danfoss Group offers a broad portfolio of AC drives for a variety of low- and medium-voltage industrial automation applications, focusing on digital solutions, process optimization, and energy efficiency. Popular Danfoss AC drives include:

• VLT AC Drives: These drives include advanced control features and condition-based monitoring capabilities to improve energy efficiency and increase machine uptime. For instance, Danfoss VLT AC drives featuring built-in intelligence can monitor the condition of connected motors and process parameters, allowing users to identify deviations in baseline process parameters early enough and intervene promptly before the deviations lead to major issues. The drives are ideally designed for food and beverage, HVAC, and water treatment applications.
• VACON AC Drives: These drives are designed to deliver robust performance while prioritizing energy efficiency and sustainability. They are ideal for industrial applications that require high power and enhanced operational reliability. They are typically used in industrial pumps, compressors, conveyors, and multi-pump systems.

Key Features

• Advanced Control Features: Danfoss VFDs incorporate complex motor control algorithms that improve motor performance and energy efficiency.
• Condition-Based Monitoring: Most Danfoss AC drives have built-in intelligence for condition-based monitoring, which enables predictive maintenance and reduces downtime.
• Connectivity and Digital Solutions: Danfoss AC drives are available with connectivity features and digital solutions, supporting various Industry 4.0 technologies such as Industrial Internet of Things (IIoT), cloud computing, cybersecurity, artificial intelligence, big data analytics, and augmented reality.
• Reliability and Durability: Danfoss VFDs are renowned for their robust design and operational reliability, even in the most demanding industrial applications and challenging environments.
• Process Optimization: Danfoss AC drives are intended to enable precise control of motor torque and speed, reducing mechanical stress, enhancing process control, and improving the service life of equipment.
• Improved Safety and Energy Efficiency: With features such as Safe Torque Off, Safe Stop, and Intelligent Heat Management, Danfoss VFDs do ensure safe and energy-efficient operations. The drives are also designed to match their output to the energy requirements of an application, which helps reduce energy consumption.
• Cost-effective Communication: Most Danfoss AC drives are available with integrated Ethernet interfaces that support all major industrial communication protocols. The interfaces include BACnet (MSTP), Modbus RTU, AS interface, Modbus TCP, BACnet/IP, and Metasys N2. The drives also support an extensive variety of serial- and Ethernet-based communication option cards, including PROFIBUS DP V1, EtherNet/IP, POWERLINK, CANopen, LONworks, EtherCAT, DeviceNet, BACnet (MSTP), and PROFINET.

Ideal Applications

• Food and Beverage
• Water and Wastewater
• Material Handling
• Refrigeration
• Textile

Note: Danfoss AC drives are mainly used in the above applications to control speed, enhance energy efficiency, and reduce operational costs.

• Marine Electrification: The Danfoss Group provides AC drives that are specially designed for marine applications, ensuring efficient and reliable equipment performance even under extreme environmental conditions. A good example are the Danfoss VFDs designed to convert the 50Hz input frequency of shore power to the 60Hz AC input typically used by the onboard systems of most sea going ships.

Delta AC Drives Overview

Delta Electronics provides a comprehensive range of microprocessor-based Variable Frequency Drives , widely used to control AC motors in a variety of industrial needs. The drives are   designed to maximize system performance, energy efficiency, and application versatility. Available Delta AC drives are largely categorized as compact or standard drives, with each category featuring specific drive series.

• Compact Delta AC Drives: These drives are designed to optimize space utilization whilst maintaining improved functionality and performance. They are ideal for general automation applications. Notable AC drives in this category include the MH300, ME300, MS300, VFD-E, VFD-EL, VFD-EL-W, and VFD-L1 series.
• Standard Delta AC Drives: These drives are intended for more demanding automation applications such as in food processing, rubber and plastics, metal processing, chemical, and municipal & infrastructure industries. They feature a robust design, providing outstanding performance and increased scalability. Examples of AC drives in this category include the C2000 Plus/C2000, C200, CH2000, REG2000, C2000-HS, and VFD-VE Series.

Key Features

• Precise Torque and Speed Control: Delta AC drives incorporate cutting-edge microprocessor technology and power electronics that enable them to accurately control motor torque and speed, even under fluctuating loads.
• User-Friendly Interface: Most Delta VFDs are available with user-friendly human-machine interfaces, including LCD displays and keypads, that allow for easy drive setup, parameter adjustment, and operation.
• Built-in Communication Features: Most Delta AC drives come with built-in communication capabilities, including CANopen and RS-485 with Modbus. They also include other integral features like PLC functionality and EMI filters. In addition, some Delta AC drive series, such as the VFD-E series, do support optional Fieldbus communication modules for connecting to a variety of Fieldbus networks, including LonWorks, DeviceNet, CANopen, and Profibus.
• Enhanced Safety: Delta VFDs prioritize safety with features like the STO and overload protection mechanisms.
• Energy Efficiency: Delta AC drives are intended to optimize energy consumption in all of their applications by allowing precise control of the speed and torque of connected motors. This enables significant energy savings.
• Compact Design: Most Delta VFDs feature a compact design, which makes them appropriate for space-constrained automation applications.

Ideal Applications

• General Industrial Automation: Delta AC drives are a perfect choice for automating a variety of industrial processes, including Logistics, Rubber and Plastics, Pumps and Fans, Elevator and Door Control, and Textile Processing, where energy efficiency and precise control are essential.
• HVAC Systems
• Water Treatment Facilities

Mitsubishi Electric AC Drives Overview

Mitsubishi Electric offers an extensive selection of Variable Frequency Drives through its FREQROL product line. These drives are designed to deliver exceptional functionality and high operational reliability across a wide range of automation applications, from simple automation systems with minimal power requirements to large and complex systems. Available Mitsubishi FREQROL AC drives include:

• FR-A Series: These AC drives are equipped with advanced AC motor control technologies, such as Real Sensorless Vector (RSV), vector control, and magnetic flux vector, to deliver excellent performance, precision, and system flexibility in an easy-to-use, safety-compliant design. They are a perfect choice for complex and demanding automation systems that need accurate motor control and advanced functionality. Available FREQROL drives in this series include the FR-A770/A701, FR-A800, FR-A800-E, and FR-A842-P VFDs. 
• FR-A800 Plus Series: These are innovative, reliable, and flexible AC drives with optimized features and functionalities geared towards meeting the specific needs of individual users. They are dedicated to specific automation applications and industries such as mining, unwinding/winding applications, and cranes. They include the FR-A800-CRN, FR-A800-R2R, and FR-A800-LC VFDs.
• FR-D700 Series: The series features simple and compact AC drives that offer outstanding performance, reliability, and durability in adverse industrial environments. They are appropriate for an extensive range of general-purpose applications requiring motor speed control.
• FR-F Series: They are exclusively designed for pumps, air conditioning, and fans in automation applications that require improved energy efficiency and enhanced performance. They include the FR-F846-E2 and FR-F800-E.
• FR-E Series (FR-E800): This series features AC drives with IEC 61508-certified safety functionalities, integral AI-based diagnostic functions, built-in corrosive gas detection circuits, and support for various industrial networks like CC-Link IE TSN. It includes the FR-E800 and FR-E700 VFDs.

Key Features

• Advanced Motor Control: Mitsubishi Electric VFDs use complex control algorithms to provide precise motor control, hence increasing efficiency and performance. Some of the advanced motor control technologies include Sensorless Vector control, Online Autotuning, Volts-per-Hertz control (fully programmable), Soft PWM function to reduce motor noise, Automatic Slip Compensation, and Active Current Limiting (provides tripless operation).
• Energy Efficiency: By using OEC technology, these drives are designed to maximize energy efficiency, resulting in significant reductions in power consumption and operational expenses.
• Robust Design: Various Mitsubishi Electric AC drive series are designed to withstand harsh industrial environments, ensuring reliable performance and durability even under extreme conditions.
• Advanced Diagnostics: The drives are equipped with AI-based diagnostic functions that monitor the health of internal drive components, enabling reliable drive operation and preventive maintenance.

Ideal Applications

Mitsubishi Electric VFDs are suitable for a variety of automation applications, including:

• HVAC Systems: The drives are used to improve energy efficiency and operational reliability in heating, ventilation, and air conditioning systems.
• General Industrial Automation: The FREQROL AC drives are widely used to provide accurate motor control in machine tools, material handling systems, and manufacturing processes.  
• Water and Wastewater Treatment: Used to improve the performance of fans and pumps in water and wastewater treatment plants.
• Data Centers: Helps save energy in cooling systems for data center environments.

Choosing the Right AC Drive Model

There are various essential factors to consider when selecting an AC drive model that can best meet your automation needs, whilst ensuring optimal performance, ease of integration, and cost-effectiveness.

1. Application Specifications: A thorough understanding of your application’s specific requirements is critical. This entails assessing the load characteristics, speed variations, torque requirements, and ambient variables of the intended drive application. For example, conveyors or cranes may require AC drives that can handle rapid acceleration and deceleration, as well as regenerative braking. Conversely, HVAC systems may prioritize energy efficiency and smooth motor control to maintain consistent airflow and temperature regulation. Aligning the drive’s capabilities with these specific operating requirements ensures greater efficiency and longevity for both the connected motor and the accompanying machinery.
2. Environmental Factors: Environmental factors can greatly impact the performance and durability of variable-frequency drives. Ambient temperature, humidity, dust, and exposure to corrosive gases/liquids all affect the drive’s reliability and lifespan. Therefore, it is critical to use AC drives that feature a robust design and are engineered to withstand your application’s unique environmental conditions. To reduce environmental risks, consider AC drives with adequate ingress protection ratings, robust cooling systems, or protective coatings.
3. Power and Performance Requirements: Effective drive selection requires determining the right power ratings and required control precision. The selected AC drive should be able to provide sufficient power to the connected motor while delivering precise control over motor speed and torque. Choosing an AC drive with the appropriate power capacity and control features guarantees peak performance and avoids potential difficulties with underperformance or inefficiency.
4. Compatibility with Existing Systems: Seamless integration of the selected VFD model with existing motion control systems and infrastructure is critical. To ensure efficient motor control and data transmission, the selected AC drive should support a variety of industrial communication protocols such as Modbus, PROFIBUS, or Ethernet/IP. Drive compatibility with the existing motion control systems helps reduce the need for major modifications, leading to significant savings in installation time and costs.
5. User Interface and Operational Simplicity: An intuitive user interface and ease of operation are required for the effective setup, monitoring, and maintenance of an AC drive system. VFD models with user-friendly interfaces, clear displays, and accessible drive parameters are easier to commission and operate. Features like guided setup wizards, real-time monitoring, and diagnostic tools also help improve the drive’s usability.
6. Financial Constraints: Budgetary limitations play an important role in decision-making. It is critical to balance initial investment expenditures with long-term operational benefits. While certain AC drive models may have greater initial costs, their sophisticated features, energy efficiency, and durability might result in reduced long-term running expenses.
7. Post-Purchase Support and Warranty Provisions: Reliable after-sales support and comprehensive warranty terms are critical for ensuring system reliability and swiftly resolving potential issues. Substantial technical assistance, readily available spare parts, and timely customer service can greatly reduce downtime and maintenance issues. As such, understanding the warranty coverage and support services provided by the manufacturer of the AC drive you intend to purchase is critical in ensuring the operational continuity of your drive system.

There are a lot of drives built for almost every application out there. At DO Supply, we carry various drives, ranging from Allen Bradley PowerFlex to Mitsubishi FREQROL FR. Stop on by our site today or give us a call and our experts will help pick out the right drive for your job. We also have another blog going over the different PowerFlex drives here.