With the technology development and promotion of sales of pure electric vehicles, there are a considerable number of consumers are willing to choose their first car purchase pure electric vehicle. What is more, it is already pure electric vehicles, “a senior player”, but have been or will be the consumer to upgrade, replace technology updates, longer battery life new EV models.
most experienced pure electric vehicles friends, for their smooth smooth dynamic feel is believed to be obsessed. There are no engine noise, cadence shift feel, it will naturally be attracted to pure electric vehicles. Hearty such experience can provide, in addition to the motor output characteristic broad, also benefited from single-stage reduction mechanism does not need to change the transmission ratio. However, recently unveiled and announced the sale price of the Porsche Taycan is the use 2AT gearbox. Why is a pure electric vehicle requires the use of transmission? And only two gears of the transmission power can achieve the kind of performance? Characteristics
Motor
known, the reaction rate of the motor fuel of the engine is more than agile and fast. According to the kind, in which the pure electric vehicles, AC motors, DC motors two categories, and is widely used at present, which thanks to the high efficiency permanent magnet synchronous motor, a wide speed range, small size, light weight, power low cost, as the main drive motor pure electric passenger car market.
An engine power formula P = (nVp) / 30t (n: speed rpm, V: displacement L, p: average pressure cylinder MPa, t: engine stroke), power and speed presenting relations are related, so that an engine (motor) for a high power output must first high speed . In general, the speed range of the permanent magnet synchronous motor can be operated between 4000-15000 rpm, the speed range of power output than conventional gasoline engines toThere are advantages.
why our car regardless of how many emissions are needed with multi-stage deceleration mechanism in order to achieve a balance between acceleration, power output and economy. The reason is that deep combustion engine by the universal characteristics limitations million ordinary general characteristics of the engine are in the range of about 1-6000rpm, in a relatively narrow region universal characteristics, range section high efficiency range is smaller, and therefore requires multi-stage gear reduction mechanism i.e. to assist the engine rotational speed falls can efficiently interval.
As previously mentioned, motor universal characteristic range more broadly, the driver only needs a good foot switches control opening and magnitude, will be able to maintain the operating range of the motor; which can get rid of the gearbox to a fixed gear ratio of the speed reduction mechanism to transmit power. In addition, the fixed gear ratio gearbox for car prices, a lot less power calibration difficulty matching.
2AT birth
Indeed motor wide output range, indeed in low-speed section provide efficient output, and can multistage reduction structure deceleration caused by mechanical loss to some extent. However, at high speed operating conditions, kept at a higher motor speed range, while not in high power output range, the motor itself consumes more power to maintain the output. Further, when the high-speed running of the vehicle, even if the surface to overcome air resistance and friction, but the power required is not large, that is to say at this time the motor part of the energy is wasted.
traditional car gearbox, after years of development and technically optimized, its stability, economy and the use ofFeel aspects of the market has been affirmed. But the cabinet size and weight, as well as its distribution power gear ratio designed for pure electric vehicles, have become more cumbersome, so most solutions do not choose the traditional auto gearbox.
In fact 2AT gearbox is no stranger to us in some models such as the import of the BMW i8, domestic WEY P8,2018 new energy models MG 6 has used a similar structure.
What kind of car is suitable?
on the Porsche Taycan, we see a pure electric car to spend 2AT gearbox, there is no doubt that in order to take into account the performance output and endurance. As can be motorized deepening of some of our less concerned with models such as buses, trucks and tractors, have already begun their motorized road.
to match the domestic commercial vehicle manufacturers specifically for the launch of the electric transmission, in the light truck can be loaded with 4.5 tons of logistics, the energy consumption of 1 kWh of electricity can run about 3.6 kilometers. In this way, while retaining the high torque electric commercial vehicle and above the zero emissions, improving the endurance of the electric commercial vehicle, increasing the single charge cycle, improve the transportation efficiency.
pure electric car gearbox or not, in my opinion not only should but also necessary. You know, deep target born pure electric car, it is to change the energy structure and reduce emissions. Looking at the current domestic production of clean electricity can not be considered a way, this way to improve the use and efficiency in automotive power becomes necessary.
Further, in a battery including a battery energy density technology, construction cost and volume key areas,Have not been able to do both at the same time in all aspects, to improve battery life by adding gearbox can be said to be a “delaying tactic” pure electric car development, to gain time for the development of battery technology.
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