New IE5 and IE7 motors allow 60% to lose less energy

During The Pace of Automation event, attendees got a first. Lenze in fact presented there all its IE5 and IE7 motors, which will not get their big baptism of fire until SPS in November. What did we already find out? That a lot of savings can still be made by choosing more energy-efficient motors! But also that these sensorless permanent magnet motors can feedback their position without additional wiring, making them a compact solution at the same time.

Electric motors account for 30% of global energy consumption. Quite a lot of potential therefore for CO2 savings, which is why energy efficiency classes for electric motors took hold. Today, IE3 is mandatory, but Lenze is already looking ahead to IE5 and IE7 at SPS. "Not all machine builders will wake up to this already, but in airports, for example, or in the warehouses of Amazon and Wallmart, the bar is already being raised," explains Lenze senior product manager Klaus Dierkes. "After all, the user benefits. The higher investment is peanuts compared to what he can save over the years through a more energy-efficient motor."

60% lose less energy

And those are hefty. Lenze did the math. A warehouse in which 800 drives of 0.75 kW are active will save 64,050 kW or 131,500 kW on an annual basis by switching from IE3 to IE5 or IE7, respectively. With current energy rates, that's good for 12,000 or 25,000 euros in savings and a reduction in CO2 emissions of 27 or 55 tons. How Lenze succeeds in this? Dierkes points out a number of elements: "First, by reducing energy losses. We manage to make 60% lose less energy, making the motors 50% more efficient. The basis is the choice of a sensorless permanent magnet motor. With the integrated control algorithms (SLSM) in the inverter, the motor continues to operate energy-efficiently even in partial load conditions while being able to absorb over-torque (up to three times higher). So you don't have to oversize. You can design the entire drive train - gearbox, motor and inverter - to suit your application." 

No additional cabling required 

There are additional benefits, which the machine builders present at The Pace of Automation were eager to hear. "For a classic synchronized motor with feedback, you need additional cabling to the encoder. Since we have experience designing both motors and inverters, we managed to create a perfect tandem. The m550 motor with the SLSM algorithm works with virtual feedback for high performance at any load, without expensive cabling. This is because the inverter knows what position the motor is in, without the need for additional electrical components, which in turn can have an impact on the life of the motor. That way, you actually get a simple servo system for a lower price. Moreover, you get a very compact machine design. In addition to the cabling, there is no longer any need for a braking resistor," Dierkes summarizes.

Energy efficient at any load

During SPS, both newcomers to the motor range will be presented in detail. Both are easily interchangeable with the existing range, Lenze has thought about that too. The IE7 motors have an equal size, the IE5 motors are just slightly smaller. "We think that with these we are bringing a solution to the market that really ticks off all requirements, because they deliver energy-efficient performance in the full range, are easy to use and simplify engineering," Dierkes concludes.