China was once known as the kingdom of bicycles, almost every Chinese is familiar with bicycles, and bicycles powered by batteries are usually transport vehicles. So, what is a touring electric bike?
Travel electric bicycles are not means of transportation, but recreational and sports fitness equipment. It is mainly driven by human power and supplemented by electric drive. At present, travel electric bicycles are on the rise, representing a new fashion for healthy living. Electric assist gives the rider a comfortable ride uphill and greatly extends the rider’s range. At the same time, like mountain bikes or road bikes, touring e-bikes are light enough for the rider to ride and hold, giving us a lot of fun rather than a painful burden.
Does it sound easy? However, building a touring e-bike to your liking isn’t easy. These characteristics of touring electric bicycles require that the power system must be small in size and light in weight, while extending the cruising range as much as possible. That is, manufacturers must squeeze the most energy out of the lightest and smallest components.
As a leading supplier of backup batteries for touring electric bicycles, Shenzhen, China-based Tritek Power knows the secrets. According to Mr. Li Changbiao, general manager of Tyco Power, the travel electric bicycle market is growing rapidly, and the current acceptance level in Europe is relatively high. Tyco Power supplies a bicycle manufacturer based in Spain, a company acquired by Mahler, a veteran German car engine maker, in late 2018. We know that the European market is very demanding on the quality of products. The spare battery packs for travel electric bicycles produced by Tyco Power fully meet the strict requirements of customers for small size, high efficiency, high reliability and electromagnetic compatibility, and no other manufacturers can compete with them. According to reports, Tyco Power’s spare battery pack weighs a little more than 2 pounds, but can provide an additional mileage of nearly 30 kilometers.
At this point, some readers may disagree: Isn’t it enough to choose a battery with high energy density? In fact, the design and production of battery packs is not that simple. For example: Does a high-horsepower car necessarily run faster? Without an efficient gearbox, the power output of the car’s engine will be greatly reduced, and such a car may not outperform a car with a smaller engine, but a more efficient gearbox and a lighter weight.
Likewise, battery packs require efficient power conversion devices. According to Mr. Li, unlike AC-driven electric motorcycles, the motor of a touring electric bike is driven by DC. Although the lithium-ion battery outputs direct current, the output voltage of the battery is not very stable with the change of battery power and external environment, so we need a DC-DC converter to provide a stable voltage for the motor. An excellent DC-DC converter must not only have a stable output, but also its conversion efficiency should be high enough to ensure that the battery power is fully utilized. He said that the overall efficiency of Tyco Power’s battery pack can be as high as 90%, which is 5% to 10% higher than that of other manufacturers’ products, and the excellent DC-DC converters are indispensable.
An excellent DC-DC converter can not only improve the utilization rate of battery power, but also reduce the heat dissipation of the battery pack, so that the heat dissipation requirements of the battery pack will be reduced, and the use of heat sinks will be avoided, thereby further reducing the battery pack’s heat dissipation. size and weight.
Tyco Power finally chose the PI3741 DC-DC power conversion module from Vicor Corporation of the United States. They have also experimented with solutions from other manufacturers, but customers are not very satisfied with the results. After choosing PI3741, Tyco Power’s battery pack products successfully passed the functional test under working conditions, as well as the certification of electromagnetic compatibility, impact resistance, waterproof and other performances.
Mr. Li said that the most prominent feature of PI3741 is high efficiency, which is the most efficient among the alternatives. It has an input voltage range of 30V to 42V and an output voltage of 42V, which is ideal for output conversion of travel e-bike backup battery packs. The thermal management design of the battery pack becomes simpler due to high efficiency and less heat dissipation. The reliability of the battery pack is also improved due to the use of fewer components.
According to Vicor’s technical support engineer Mr. Yu Xunlong, the reason why PI3741 has excellent high efficiency is because it adopts Vicor’s proprietary on-chip zero-voltage switching (ZVS) technology. We know that in order to make the overall size of the power conversion solution smaller, we must increase the frequency of the switching power supply, and the accompanying increase is usually the switching loss. ZVS technology makes the voltage in the switching process zero, so-called soft switching, so that the silicon loss in the switching process is reduced.
The soft switching technology itself is not unique to Vicor, but only Vicor integrates the ZVS topology into the chip, which achieves high integration under high conversion efficiency, reduces the number of external components, reduces the solution size, and improves product reliability. .
Mr. Yu said that the PI3741 module provided by Vicor to Tyco Power is packaged in LGIZ form, which is more convenient for heat dissipation. The size is only 10mm x 14mm x 2.5mm, and the conversion efficiency can be as high as 96%, which is two percentage points higher than competing products. . He said that Vicor’s products have always been known for high quality, and the defective rate of PI3741 is only two or three ppm. In addition, PI3741 has very low EMI radiation, which helps customers’ end products to meet the strict quality certification in Europe and the United States.
Well, that concludes the story of touring electric bikes, spare battery packs and DC-DC converters. Although the pace of hiking is limited in the spring and summer of 2020, the clouds will eventually dissipate, and the sun will be better tomorrow. At that time, travel electric bicycles will carry more people who love life to enjoy the gifts of nature and the convenience of new technologies.
The Links: LB070WV8-SL02 CM200DU-24NFH IGBT-MODULE