Dubai, UAE, 15 October 2018: Danfoss discussed challenges and trends in Variable Frequency Drives (VFD) during a CPD-approved seminar on October 10, in Dubai. The seminar was attended by consultants, contractors and engineering professionals and touched on harmonics, energy efficiency and what to consider when specifying VFDs.

Gregers Geilager

Gregers Geilager, Head of Premium Drives, Product Management, Danfoss Drives, kicked off the seminar with an introduction to harmonics and mitigation techniques. “Harmonics are not always the problem,” he said, “you need to know when to do something about it and when not to do something about it. As we improve energy efficiency, we tend to use more and more drives. The more drives we install, the bigger the problem.” Geilager defined harmonic distortions as repetitive and continuous deformations of the voltage or current waveforms. Geilager explained that the power grid normally experiences huge variations of load and reacts to changes in the voltage waveform, adding that causes of power disturbances range from electrical switching circuits to lighting. He also spoke on how harmonics could impact temperature and make a motor wear out prematurely, outlined different standards in place, in addition to what constitutes good engineering practice with regard to mitigation solutions.

Geilager outlined particular technical conditions that should encourage stakeholders to reflect and calculate on harmonics, and provided recommendations on what should be done in the event a problem occurs, stressing that stakeholders should not use mitigation equipment, if not needed. Geilager added there is no single solution that gives the best performance, at lowest cost, with the highest efficiency, satisfies all norms, is applicable to all sizes of drives and can be used in new and retrofit solutions. The best fit, he said, is considering many applications and aspects.

Niko Honkonen

Niko Honkonen, Product Manager, Danfoss Drives, spoke on energy efficiency in the context of AC drive solutions and trends. Honkonen looked at the basis of why the use of an AC speed control system saves energy, providing different examples and solutions. “AC Drives, depending on application, can save 15-40% of energy,” he said, adding there is the opportunity to save up to eight per cent of the world’s electricity consumption by using Variable Speed Drives coupled with the necessary optimisations. The key, he stressed, is not have the motor system run at fixed speed. Honkonen also spoke on regulations and standards related to motors and drivers, globally.

Geilager ended the seminar by outlining things to consider in specifying VFDs. “We should have an open and honest dialogue about it, before diving into technical aspects,” he said. “There is a lot to consider with picking a drive, don’t look at the drive itself but the whole installation.” Issues related to the grid, motor and applications, he added, must be considered in addition to specific things inside the drive itself, to ensure a long-term, cost-effective solution. Geilager also touched on EMC, which he defined as the ability of equipment to function satisfactorily in its electromagnetic environment without introducing intolerable disturbances to its environment. Geilager also discussed consequences of poor or no grounding, outlined good EMC practice and defined common mode voltage, ending with recommendations on where stakeholders must direct their attention by looking into aggravating factors in the system, as well as possible applications of various measures to address this.

John Conboy

John Conboy, Director of Sales, Marketing and Service, Danfoss Drives Segment, Middle East and North Africa, Danfoss, said the seminar falls in line with the company’s efforts to promote itself as a thought leader in the region. “A lot of companies are focusing on point of sale, whereas we as a company are making sure that the right selection of equipment is made in the right areas and that all stakeholders are involved,” he said. Conboy added that this is especially the case with end-users, who bear the brunt of high energy cost, owing to inefficiencies. “Unfortunately, in the projects we see happening today that person is not being taken into consideration,” he said. “It’s more about the capex spend and there are people who are not paying the energy bill taking decisions on equipment that should be installed, which will have an impact down the line.” The seminar, Conboy said, aimed to inform stakeholders on what technology can to be used to ensure a more cost-effective opex.

Hannah Jo Uy is Assistant Editor at Climate Control Middle East magazine. She may be contacted at hannah@cpi-industry.com