Bauma Interview: ABB inverter uses three-level topology

HES580-3L mobile inverter (Photo: ABB)

ABB is well known for its vast range of power solutions intended for the electrification and automation markets. Following on from the remit to deliver products which are both more effective and more efficient over each successive generation, the Swedish/Swiss company premiered the HES580-3L mobile inverter at Bauma 2025 in Munich, which offers a series of noteworthy improvements over preceding models.

“When it comes to drives in the mobile off-highway market, I’d say it’s the most innovative product you will find at Bauma,” said David Segbers, global head of Product Management, Mobile ePower Products. While he may be obliged to describe the new inverter in such glowing terms, Segbers says it’s not just hype. “I’m really convinced that we’ve done something different here, particularly when it comes to the three-level topology.”

Internal design

The three-level topology he’s referring to is intended to deliver a smoother electric current and a more energy efficient solution than those units which use a two-level system.

“I’d say it’s the most friendly drive for powering electric motors” David Segbers, ABB

Where a two-level model can only switch between plus (+) and minus (-), a three-level model can switch between plus (+), minus (-) and zero (0). Switching directly between + and – creates a ripple in the electrical current which reduces the efficiency of the current delivery and can, over time, damage the electric motor. The three-level topology reduces that ripple, almost eliminating any of the negative side effects.

“The three-level topology is realised by the arrangement of the semi-conductors. This layout helps us to reduce the harmonic losses in the motor by up to 75%, increasing motor efficiency and lowering the temperature. This means it requires less cooling, or more power can be delivered to the motor compared to a two-level inverter.

“Also, the smoother switching creates less stress on the bearings and winding insulation, which helps extend the motor’s operational lifetime. I’d say it’s the most friendly drive for powering electric motors,” Segbers explains.

Efficiency improvements

“The HES580 is really innovative in terms of solution delivery. It supports improved energy efficiency and we believe that this will become more important, particularly when working with battery power,” says Segbers. “Or if you’re working with a hybrid diesel/electric propulsion unit, the inverter will help to reduce diesel fuel consumption.”

ABB has already shown in a rail application that the three-level topology can deliver energy savings of up to 30%. The rail industry is known to be quite conservative when dealing with new technology, but Segbers says that’s balanced by a need for improved energy efficiency. He believes that it is “highly likely” that similar numbers will be achieved with off-highway machines, but makes it clear this is dependent on the operational profile.

But as Segbers notes, it’s not that three-level topology itself is new, it’s that the solution is now available for the mobile off-highway market.

“We’re targeting a range of applications in the construction and mining industries, a series of different machines ranging from underground mining trucks, through to loaders and electric excavators. It won’t change how they operate, but the new inverter will help to deliver overall energy savings.”