ABB marks 50 years of VSD innovation

The LV VSD addressed a long-standing limitation of the traditional squirrel-cage induction motor, which had remained fixed-speed since its invention by Nikola Tesla in 1888. Prior to the introduction of VSDs, adjusting motor performance for variable loads typically relied on mechanical throttling methods, such as dampers or valves - solutions that did little in terms of energy efficiency.

“For 50 years, ABB’s low voltage drives have been a part of many era-defining technologies and breakthroughs, from electric public transport to today’s push for energy-efficient, low-carbon industries. Before the VSD, getting a fixed-speed motor to deliver the right output was like driving your car with your foot all the way down on the accelerator, and braking at the same time to control your speed,” explains Tuomo Hoysniemi, president of drive products at ABB.

“Commercially, this is an incredibly expensive problem, but in terms of energy efficiency, it’s even worse. With a Variable Speed Drive, you can be precise about output, dramatically improving industrial energy efficiency. Low voltage VSDs were a major breakthrough. They have since become the gold standard and have seen wider and faster adoption, but still to this day, less than 25% of industrial motors worldwide are connected with a drive.”

The first commercial LV VSDs were developed in the early 1970s by Strömberg, a Finnish electrical engineering company that would become part of ABB in the 1980s. In 1975, the company launched the SAMI A (Strömberg Asynchronous Motor Inverter), the first low voltage drive capable of precisely regulating the speed of an AC induction motor.

The first real-world installation of the SAMI A took place later that year at the Karihaara sawmill in northern Finland, using three 350 kVA/500 V units. This demonstrated that variable speed control could offer measurable efficiency and reliability benefits in an industrial environment. The technology quickly expanded into new sectors and applications, including Helsinki’s metro system, where it supported smoother, more energy-efficient public transport.

Martti Harmoinen (pictured), the Strömberg engineer credited with leading the original development team, received the Finnish Engineering Award in 1981 and the honorary title of Professor in 1995.

“Not every motor on the planet can be fitted with a Variable Speed Drive, but there is no question that most of them should be,” said Chris Poynter, president of motion high power at ABB. “There is a perception that sustainability is cost-prohibitive, but energy efficiency and decarbonization in an industrial setting are commercially prudent as well as fulfilling our duty to the planet. The total cost of ownership of running a motor with a VSD is far lower than working it to an early failure.”

Independent studies suggest that if VSDs were applied more broadly, including both constant and variable flow applications like pumps, fans, and compressors, annual energy consumption in EU could be reduced by around 140 terawatt-hours. ABB estimates that using VSDs in these scenarios can lead to energy savings of up to 12% per installation.

Though Martti Harmoinen passed away in 2023, his work remains central to ABB's mission to advance smart, efficient motor systems worldwide. ABB today is a market leader in the design and manufacture of VSDs, and continuously invests in cutting-edge technologies to realize the full energy efficiency potential of global industry. In the next 50 years, we may see further advances and the universal adoption of drives - or something completely new. Whatever the occasion, ABB will rise to meet it.

To find out more about the history and impact of the Low Voltage Variable Speed Drive, visit 50 years of LV drives | ABB.