How to create greater VFD efficiencies, reduce carbon emissions

There are several key drivers for the adoption of variable frequency drives (VFDs) and sustainability is a major one.

By Kes Beech July 9, 2023
Courtesy: Control Engineering Europe/Invertek

Variable frequency drive (VFD) insights

  • Variable frequency drives (VFDs) play a key role in companies reducing energy due to rising costs.
  • Inefficient motors create higher energy use which in turn generates increased carbon emissions.

Sustainability is becoming an important driver for the adoption of variable frequency drive (VFD) technology today. While sustainability covers a very broad area, sat within this is a need to reduce energy use and its associated emissions, which can support business and industry’s impact and responsibility on society and achieve impressive energy savings through increased process efficiencies.

Energy reduction has also been rising to the forefront of most commercial strategies today, due to soaring energy costs. Identifying ways to reduce energy use has become vital, and VFDs are a key component in achieving this within electric motor applications – from material handling to pump control.

Processes can be made more efficient and energy use can be reduced by as much as 50% in some cases where VFDs are used within them.

The figures are frightening – around eight billion electric motors consume nearly 50% of the electricity produced in Europe. Globally, 40% of electricity is used to power industry, with two-thirds of this used by electric motors. And yet less than 20% of electric motors are controlled by VFDs.

Electric motors account for a significant proportion of electricity usage globally. And it’s not just in industry. Our everyday lives are impacted by ac motors in one way or another, from HVAC building systems to retail refrigeration.

Inefficient motors create higher energy use which in turn generates increased carbon emissions. And it’s not just the energy that’s contributing to these emissions. The processes themselves, such as those in manufacturing, the water industry and ventilation, can also impact on emissions or have environmental ramifications if they are not accurately controlled.

JCV Maq, a manufacturer of food packaging and sealing solutions provides a good example of how more efficient machines can help reduce environmental issues.

The company looked for a solution to help ensure greater sustainability for its customers. It wanted to be able to offer its food industry customers increased productivity, while reducing packaging costs and wastage. The addition of VFDs has increased the precision of one of its packaging sealing machines, resulting in improved speed and motor accuracy and a subsequent reduction in film packaging waste.

With the original VFDs used in the machine, JCV Maq found it difficult to accurately control the precision of the machine at start/stop which was resulting in excess packaging being fed through for each product sealed. A start/stop ramp of almost zero was needed to address this problem.

Working with Altus, a sales partner of Invertek Drives in Brazil, the addition of VFDs brought about immediate improvements and efficiencies – it has resulted in less packaging waste, even at increased speeds

Three VFDs in Frame Size 1 enclosures were utilized. One installed to control the movement of the film, another to control the unwinder, and the third controls the packaging mat. The VFD in frame size one meant that the drives were compact enough to be installed and commissioned easily on the machines without taking up much space

The precision provided by the VFDs enabled JCV Maq to offer their customers a more efficient and productive product that helps them reduce costs through package wastage while increasing productivity.

Energy savings through VFDs

The more efficient control of the VFDs has also provided potential energy savings of over 20% – by optimizing motor start-up, running and stopping of rubber compounder mills, for Clwyd Compounders. In addition, the VFDs have reduced wear and tear on its mill motors, reducing long-term maintenance costs and downtime.

Clwyd Compounders produces a variety of rubber compounds, which requires its mills to be capable of operating with materials weighing up to three tons that need to be able to quickly stop and reverse to ensure they meet European EN safety standards.

If a safety bar is pressed in an emergency, the mill rolls have to separate by 35mm within three seconds, and additionally, the three-ton rolls must stop within one-sixth of a revolution. In addition, automatic reversal of the rolls has to occur within two seconds of the mill stopping.

The mills vary in size, with 30 to 250 kW motors operating at speeds up to 1,000 RPM. The rolls themselves often operate around 30 RPM, depending on the material.

The mills also need to be able to safely shut down if the mains power supply is lost, which is something that had proved challenging in the past as it requires the drives to be capable of recovering enough energy from the mill itself to accomplish a safe stopping condition within the allowed time.

Clwyd Compounders found the VFDs was able to meet all of its motor control requirements. Further, a fast stop on mains loss feature ensures the machines adhere to the required safety standard. Additionally, the VFDs Function Block programming feature has also enabled Clwyd Compounders to create a simple system for the necessary automatic reversing requirements.

Meeting climate ambitions

Globally, VFD technology is already cutting energy use by up to 30 or 40% in many applications, helping to reduce carbon emissions. But, with less than 20% of electric motors currently controlled by drives, the technology still has much more to give. With increased adoption of VFD technology, significant inroads could be made to meeting global climate ambitions.

VFDs can be easily retrofitted onto existing electric motor processes and integrated into new applications. We don’t need to look to the future for a solution – the technology already exists! But the drives industry, governments and trade organisations, need to work harder to promote and encourage greater use of VFDs in existing and future motor-controlled applications.

With more motor-based systems integrated with VFDs, it is possible to create greater efficiencies, reduce energy use and cut carbon emissions.

– This originally appeared on Control Engineering Europe. Edited by Chris Vavra, web content manager, CFE Media and Technology, cvavra@cfemedia.com.


Author Bio: Kes Beech is technical manager at Invertek.