Motors, Drives

VFDs: six benefits, energy efficiency

Drives: A growing emphasis on boosting energy efficiency and meeting energy requirements are increasing demand for variable frequency drives (VFDs).
By Aishwarya Vijay September 28, 2018
Pumps, fans, and conveyors are the largest area for variable frequency drives in China. Courtesy: Grand View Research

AC drives lead the mix of variable frequency drives, globally. Courtesy: Grand View ResearchThe global variable frequency drive (VFD) market is slated to experience healthy growth over the coming years. These drives are emerging as an integral part of several machine markets globally both small- and large-scale. They are used in applications ranging from small devices to large compressors. VFDs are power conversion devices that are available as ac drives, dc drives, and servo drives.

Board members of the small village of Enosburg Falls, Vt., approved the purchase of a new VFD for well pump of village’s water department. This step is likely to cut down the annual electric bill of the department by $2,000. On the other end of the scale, VFDs are an imperative part of the technology behind the longest single-flight pipe conveyor of the world.

It is estimated electric motors in industrial applications consume approximately one-fourth of the world’s electrical energy. When these motors are incorporated with VFDs in centrifugal load service, their efficiency increases. With technological advancements in power electronics technology, VFD cost and size have decreased, while performance has improved.

The EU has proposed to revise its goal under the Energy Efficiency Directive from target of 20% by 2020 to 30% target by 2030. This includes incentives to small and medium-sized enterprises (SMEs) to monitor efficiency levels in new capacities for energy generation and undergo energy audits. This is likely to boost the incorporation of VFDs in conveyors, electric fans, industrial pumps, and HVAC, among others.

VFD advantages

Globally, VFDs are used across several end-use sectors, including infrastructure, industrial, power generation, and oil and gas. Growing concerns regarding energy efficiency worldwide coupled with rising awareness about benefits of these drives are boosting their adoption across these sectors. For instance, as per a recent announcement by Simark Controls Ltd., they received a follow-up order of $849,937 ($1.1 million Canadian) for integrated VFDs from an existing customer in the Alberta oil sands. In the oil & gas sector, these drives help in reducing installation and operating costs, optimizing pump operations, improving pump uptimes, and boosting oil production.

Six primary benefits of VFDs are:

Pumps, fans, and conveyors are the largest area for variable frequency drives in China. Courtesy: Grand View Research1. Keeps starting current in control: A VFD has the capability of starting the motor at zero voltage and frequency, which keeps a check on motor winding flexing and heat generation. This helps in extending the motor life.

2. Reduces power line disturbances: Any voltage sag caused in the power line can adversely affect voltage sensitive devices such as proximity switches, sensors, and computers. Using VFDs eliminates voltage sag.

3. Demands lower power on start: Power required to start an ac motor across the line is substantially greater than with a VFD. When industrial customers start these motors during peak hours of electrical consumption, they are likely to be charged with surge prices. However, with VFD demanding lower starting power, the issue can be addressed.

4. Helps in controlling operating speed and acceleration: Applications such as bottling lines that include easy-to-tip product significantly benefit from a gradual increase in power. This allows conveyer belts to smoothly rev up rather than an abrupt jerk to full power. They also allow speed to be remotely adjusted by a controller. Control is speed and acceleration is a big bonus to industries in a production process.

5. Limits and adjusts torque: The drive is capable of limiting and adjusting the amount of torque so the ac motor never surpasses this limit. This protects machinery from damage and protects the process or product.

6. Saves energy and cost: A VFD regulating a pump motor that usually runs less than full speed can cut down energy consumption over a motor running at constant speed for the same period. In addition, it eliminates the need for mechanical drive components, which also helps reduce overall costs.

Competition from substitutes

Several VFD substitutes are available on the market. Soft-starter drives are one of the biggest and are. useful in limiting inrush current associated with electric motor startup. They lower the initial voltage and ramp up until desired speed is attained. Soft-starter advantages include easy set-up and they’re cheaper compared to VFDs. They’re also designed to extend motor life.

VFDs do not perform as needed in no flow or near-zero flow conditions and may not be well-suited for specialist applications. In these cases, instantaneous high-speed response is required. These drives are acknowledged for the ability to deliver higher frequency source power during startup, which is beneficial if control is sought after the desired speed is attained.

Demand trends for VFDs

A report by Grand View Research indicates the global VFD market size will reach an estimated $33.10 billion by 2025. Growing emphasis from government organizations to reduce energy consumption to achieve a net zero energy goal is one of the key trends contributing to the growth of the market. Rapid technological advancements along with proliferation of connected devices in commercial, household, and industrial sectors are anticipated to bolster the demand for VFDs.

Energy efficiency is needed to not only meet burgeoning power requirements, but curtail greenhouse emissions. On a global scale, energy efficiency can reduce greenhouse emissions by around 40%.

This increased focus on augmenting energy efficiency is poised to increase VFD adoption. In 2016, total investments in energy efficiency were valued at $231 billion. In this, investments in appliances, lighting, and HVAC and control amounted to $13.94 billion, $27.42 billion, and $22.86 billion, respectively. With surging energy consumption and its unit rate, operational engineers in several process sectors are trending toward VFDs for productivity, optimum operation, and improved energy efficiency of machines. This also is projected to stir up the demand for VFDs across applications such as automotive, HVAC, and elevators.

Aishwarya Vijay is a content creation executive at Grand View Research. Courtesy: Grand View ResearchAsia Pacific is slightly ahead of other regions in revenue generated through sales of VFDs thanks to rapidly improving economic conditions in countries such as India and China. Governments and other organizations in these countries are pouring hefty funds into energy efficient devices.

Latin America also is expected to be a promising region because of stringent regulations and law enforcement for the use of energy efficient devices. Developed regions such as North America and Europe also are likely to witness healthy growth over the coming years.

Aishwarya Vijay is a content creation executive at Grand View Research. Edited by Mark T. Hoske, content manager, Control Engineering, CFE Media, mhoske@cfemedia.com.

KEYWORDS: VFDs, energy efficiency

Variable frequency drives (VFDs) can help even small organizations realize energy savings.

Cost and size of VFDs have decreased; performance has improved.

Other benefits of VFDs include less line disturbances, less maintenance, and longer motor life.

CONSIDER THIS

Next steps might include an assessment to see where new VFD technologies could help.

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Author bio: Aishwarya Vijay is a content creation executive at Grand View Research, with more than two years of experience in business writing. She has written several guest blogs and has a keen eye for technological advancements and breakthroughs in different sectors.


Aishwarya Vijay
Author Bio: Content creation executive at Grand View Research.