About the technology

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What is Form Litz Winding

Form Litz Wire consists of parallel wires packed into a highly compact form winding found in the stator of high power density electric motors. Its better heat transfer goes beyond the potential of current winding solutions, which is needed in modern designs and even more so in future automotive powertrain solutions. This is the best solution for high-power applications since its copper filling density reaches up to 65%, making it comparable to Hairpin winding. At the same time, its high-frequency performance is as good as pull-ins.
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Mitigation of proximity and skin effects

The proximity effect is one of those power loss factors that is often largely overlooked. However, this phenomenon can be several times more significant than the skin effect since it causes other nearby conductors' non-uniform distribution of AC current. It is one of the most critical factors in controlling losses within the winding solutions. Another notable effect is the so-called "skin effect." When current flows through a single wire conductor, the current is increasingly pushed toward the surface "skin" of the conductor as frequency increases—using Litz Wire winding helps to reduce the skin effects significantly. The current flows through nearly the entire cross-section of each wire, thus minimizing AC resistance and heat losses.
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Reduction of footprint and weight

Developing e-motors, stators, and rotors requires a high use of rare earth metals, among other materials. Using hofer powertrain Form Litz Winding technology helps considerably reduces these amounts. Reduced material usage in the entire housing minimizes its overall package size and weight.
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Effortless industrialization

No complex tools or time-consuming and error-prone manual production steps are required in the manufacturing process since the technology can use the existing Hairpon equipment. One of the benefits here is the ability to achieve high quality with short cycle times. On top of that, industrialization proves highly scalable with high reproducibility and smaller manufacturing tolerances.
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Extended driving range up to 2%

Depending on the e-motor, the solution can significantly increase the driving range of batteries while improving their life and durability. Both energy consumption and energy losses are reduced compared to solutions with Hairpin winding.

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