At the Xiaomi EV Technology Launch, the company formally unveiled the five key technologies of the Xiaomi EV: the E-Motors, Battery, Die-Casting, Xiaomi Pilot Autonomous Driving, and Smart Cabin. Xiaomi EV SU7’s latest breakthrough in motor technology, the HyperEngine V8s, not only showcases the company’s prowess in innovation but also sets a new standard for motor efficiency and performance. In this blog post, we delve into the key advancements that have enabled Xiaomi to achieve this feat.
Optimizing Rotor Stress with AI Simulation Technology
At the inception of the design process, Xiaomi’s engineering team employed AI simulation technology. Over eight months and 200,000 iterations of electromagnetic and structural coupling AI simulations, coupled with multiple rounds of sample prototyping, the HyperEngine V8s was born.
Today, AI-driven design has become mainstream among leading automotive manufacturers, facilitating rapid generation of recommended solutions in areas such as body structure and material selection. Xiaomi’s utilization of advanced AI simulation technology underscores its technological prowess in this domain.
Higher Manufacturing Processes
The HyperEngine V8 achieves an impressive motor efficiency of 98.11%. This is attributed to its differentiated thickness design of stator and rotor silicon steel sheets, combining ultra-thin (0.2mm) stator silicon steel laminations with ultra-high-strength (0.35mm) rotor silicon laminations, balancing strength and efficiency.
Furthermore, the application of high-performance neodymium iron boron permanent magnets breaks away from traditional 54-slot 6-pole design patents, adopting an 8-layer Hairpin flat wire winding with a slot fill factor of up to 77%.
By employing advanced manufacturing processes and winding methods, Xiaomi enhances slot fill factor, thereby improving motor efficiency and output power.
S-Shaped Oil Circuit Design And Bidirectional Full Oil Cooling Technology
The HyperEngine V8s incorporates dual-directional full oil cooling and an S-shaped stereoscopic oil circuit design.
The stator section utilizes a dual-cycle stereoscopic oil circuit, increasing motor heat dissipation area by 100% and achieving a maximum temperature reduction of 20 degrees Celsius. Meanwhile, the rotor section employs a patented S-shaped oil circuit, increasing heat dissipation area by 50% and achieving a maximum temperature reduction of 30 degrees Celsius.
Additionally, HyperEngine V6 /V6s and HyperEngine V8s motor stators employ the staggered silicon steel laminations design, further increasing the effective heat dissipation area by 7%.
Currently, high-power motors employ full oil cooling for temperature reduction, with the stator’s dual-cycle stereoscopic oil circuit effectively increasing the circulation system to enhance stator cooling. Sustained optimal temperature is crucial for ensuring the motor operates at its best.
Xiaomi’s motor design demonstrates innovation in oil circuit design, heat dissipation area, and stereoscopic circulation.
Advancements in Electric Motor Materials
Xiaomi unveils the industry’s first 960MPa ultra-high-strength special silicon steel sheets, surpassing the industry standard by more than twice (450MPa), enhancing strength.
As motor speeds increase, significant centrifugal forces and stresses are generated within the motor, necessitating reinforcement of the materials used in the rotating components.
Xiaomi once again raises the industry standard by doubling the strength to ensure stability of the rotor at high speeds.
Conclusion
Compared with Tesla Model 3, Xiaomi’s HyperEngine V8s represents a significant milestone in motor technology, showcasing a blend of innovation and engineering excellence. Core technology is like bricks and stones. Building a solid house requires the accumulation of many bricks and stones. Xiaomi’s pursuit of the highest speed of the motor is by no means a show of skill, but a solid step forward. Xiaomi’s leading technology in super motors is by no means as simple as the above points.
As shown at the press conference, Xiaomi has applied for 155 patents for this motor, of which 60 have been authorized. It has also reached the “international leading level” certified by the China Electrotechnical Society and the National Innovation Center in terms of the maximum speed of the motor, the maximum efficiency of the electric drive, and the power density.
