What was the secret that allowed Hyundai Motor Group and Kia electric vehicles to achieve performance comparable to a supercar? A technical video explaining the secret that achieved not only performance but also efficiency has been released.
Hyundai Motor Group and Kia released a technical video on Hyundai Motor Group's YouTube channel that provides a detailed introduction to the "2-stage motor system," which won the highest honor, the presidential award, at the 'Korea Technology Awards' organized by the Ministry of Trade, Industry and Energy at the end of last year. Inside, the advanced motor drive control technology that captured both performance and efficiency is clearly explained so that even those without specialized knowledge can easily understand it.
As with the "brake operation principle" video recently posted on the same channel, this is interpreted as Hyundai Motor Group's intention to continue communicating with customers centered on technology.
The video begins by introducing the three main components of a basic motor drive system. The motor generates torque, the reducer transmits that torque to the wheels, and the inverter is responsible for converting the battery's direct current power into alternating current.
Generally, if a motor drive system for an electric vehicle is designed mainly for high output, there is a limit in efficiency during urban driving. To overcome this, Hyundai Motor Group and Kia focused on the role of the inverter.
Existing electric vehicle inverters use six switches composed of silicon carbide semiconductor devices. Hyundai Motor Group and Kia added six silicon power semiconductor devices to this, devising a 2-stage motor system composed of a total of 12 switches. As a result, the voltage that can be applied to the motor can be expanded by up to 70% compared to before, which leads to increased output.
In everyday driving, only the original set of six switches is used to maintain efficiency, while in high-speed, high-output situations both sets can be used to reliably produce powerful performance. Hyundai Motor Group and Kia explain that simply doubling the number of switches in the inverter does not solve all problems, because as switches increase the range that must be controlled also expands.
To address this, Hyundai Motor Group and Kia applied proprietary control methods and a mode-switching control algorithm so that transitions to each mode occur naturally without any sense of mismatch.
The 2-stage motor system has been applied to the Kia EV6 GT and is receiving favorable reviews after being applied to Hyundai Motor's Ioniq 5N, Ioniq 6N, Ioniq 9, and the all-new NEXO. Hyundai Motor Group and Kia plan to expand the application of this technology to electric vehicles to be released in the future.
Hyundai Motor Group and Kia have filed a total of 47 patents for the core technologies of the 2-stage motor system in countries including Korea, the United States, Europe, China and Japan.
Researchers who participated in the development of the 2-stage motor system said, "We are confident it is an innovative motor system that uniquely achieves both high output and high efficiency in the world," and added, "When we received the presidential award at the Korea Technology Awards last year, and when we heard that competitors were buying and disassembling our electric vehicles to examine them, I felt a real sense of pride that we had done something truly meaningful."
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