Time:2024.12.23Browse:0
Before the sudden rise of Tesla, I used to believe that there would be no rapid development or disruptive revolution in battery energy storage technology for electric vehicles in the short term. At present, although Tesla can achieve huge breakthroughs in the field of battery safety management, I still believe that "pure electric vehicles" are not the best products for consumers. In the foreseeable future, they will be able to defeat fuel vehicles and hybrid vehicles. It is not a "pure electric vehicle", but an "extended range electric vehicle" such as the VOLT produced by General Motors and the ideal ONE for cars and homes. What is a range-extended electric vehicle? The extended-range electric vehicle adopts a series hybrid structure and is a type of plug-in hybrid vehicle. The motor directly drives the vehicle and the engine does not participate in the driving. It can be regarded as a small-capacity pure electric vehicle, with an additional generator added to allow the vehicle to charge while driving. When the battery power is low, the vehicle generates electricity through the operation of the extended-range engine. Part of the generated electric energy is used to directly drive the motor, and the other part is used to charge the battery. When the electric energy of the battery reaches a certain upper limit, the extended-range engine stops working and the battery directly drives the motor. As the driving time and mileage increase, the consumption of the battery becomes larger and larger. When the electric energy of the battery falls below a certain lower limit, the increase The engine started working again. In this way, the extended-range engine will always be in a cyclic working state, and the start and stop of the engine completely depends on the power supply of the battery. Different from "hybrid vehicles that have both a fuel system and an electric system", although extended-range electric vehicles also require gasoline, hydrogen and other fuels when driving long distances, gasoline is only used to generate electricity and use electricity to drive the vehicle. Rather than using gasoline to directly drive the car when the power is exhausted, like a hybrid, it does not even need a gearbox, so its structure is much simpler than hybrid cars and plug-in hybrid cars; and in extended-range mode, Its engine always works in the optimal speed range without frequent starts and stops, and is more energy-saving and efficient than ordinary hybrid vehicles. In addition, the "extended range electric vehicle" itself can use external power to charge its battery, just like the plug-in Chaos vehicle. It can also power the battery through energy recovery when braking and decelerating. Therefore, extended-range electric vehicles not only have the driving qualities of pure electric vehicles, but can also effectively solve the current problem of insufficient cruising range of electric vehicles. Based on this, I believe that on the premise that there will be no rapid development or disruptive revolution in battery energy storage technology in a short period of time, "extended range electric vehicles" will become popular and be widely sought after and welcomed by the market. What are the advantages of extended-range electric vehicles? Compared with hybrid vehicles, extended-range electric vehicles usually operate at a fixed operating point of high speed and high power when the engine is turned on, which will reduce the engine's fuel economy. When the engine has excess energy, it will use energy first. A portion of the energy is stored by transmitting it to the battery pack and then driving the motor. While increasing the transmission process, it also increases energy loss. However, after the range extender is turned on, the range extender vehicle will adjust the output power of the engine according to the power demand of the drive motor, trying to make it work in the best working curve to achieve better economic performance. Compared with traditional fuel engines, the engine equipped with a range extender has a smaller displacement, less power and less noise when working, but has higher working efficiency. Moreover, in the structural design of the vehicle, the range extender only consists of a generator and an engine. It has a simple structure, high energy transmission efficiency, and ideal fuel consumption and emissions. In addition, the motor of the extended-range vehicle can also recycle the energy of vehicle braking and downhill, reducing energy loss. Compared with ordinary pure electric vehicles, the range extender of an extended-range electric vehicle can charge the power battery while the vehicle is driving, greatly increasing the vehicle's cruising range. At the same time, the on-board power battery it is equipped with is much smaller than the power battery of pure electric vehicles of similar models, which greatly reduces the manufacturing and production costs of the vehicle. In addition, when the range extender is turned on, it can also share the risk of over-discharge of the power battery pack, which is beneficial to extending the service life of the battery pack. When driving, the vehicle is completely driven by the electric motor, so the engine can maintain the "optimal speed" to generate electricity throughout the entire process. Under such circumstances, even "using oil to generate electricity first and then driving on electricity" is more energy-saving than many vehicles that are directly driven by oil. Moreover, the engine displacement used in most extended-range electric vehicles is relatively small, many even only 0.5L. Although it is difficult to drive the vehicle, it can complete the task of generating electricity well, and the fuel consumption will naturally be higher. It is much lower than the 1.5L and 2.0L models, but it can still be as powerful as a pure electric vehicle in terms of power, bursting out powerful low-speed torque and relatively fast starting speed in an instant. Moreover, almost all extended-range electric vehicles also support the use of charging piles for charging. Within the capacity range of the power battery, the vehicle can still travel a certain distance with zero emissions, further reducing overall fuel consumption and emissions. Coupled with its low engine displacement and other factors, the operating noise is also lower than that of large-displacement engines, and the vehicle's quiet effect is better than that of most traditional fuel vehicles. How does an extended-range electric vehicle work? At present, in terms of technical solutions for range extenders, there should be two trends: 1. Based on the architecture of pure electric vehicles, a small range extender is inserted into the space. Plug-in pure electric battery life should also ensure urban commuting battery life under actual pure electric driving conditions (rather than NEDC) under the condition that SoC30% triggers range extension. It is recommended that the NEDC equivalent battery life be more than 200km. Then, the small range extender should be as simple and lightweight as possible to simplify the working conditions. This extended-range architecture can be developed based on a pure electric architecture. 2. Direct-drive engine power generation based on micro-hybrid/hybrid architecture. The gearbox and driveshaft are eliminated, and both front-wheel drive and four-wheel drive are available with electric drive. Among them, the important point is to control the battery power and reduce costs. The power of the engine must be greater than or equal to the rated power of the motor (or more than half of the peak power). Through the optimization of the strategy, it is necessary to ensure that the engine's operating condition range is as narrow as possible while considering direct drive under various engine operating conditions. In this way, the engine can avoid being a full-working engine, at least locking the speed, and simplifying the complexity of the timing system. Can the range extender be directly involved in driving? Usually when we talk about plug-in hybrids and non-plug-in hybrids, both the motor and the engine can drive the vehicle, so the design of the chassis and vehicle power structure is very complex. The engine of an extended-range electric vehicle does not directly participate in driving the vehicle, so the difficulty in design and production is greatly reduced. So, is it possible that in congested urban sections, the engine of the extended-range electric vehicle is only used to generate electricity, but on smooth highway conditions, the engine of the extended-range electric vehicle can also directly participate in driving the vehicle, thereby achieving At the same time, what is the effect of greatly saving fuel in congested urban sections and smooth highway sections? The answer is: For new range-extended electric vehicles, it really can! In fact, the VOLTEC technology used in Chevrolet VOLT already has such a function, consisting of dual motors, a planetary gear set and a power distribution module. This combination of dual motors + planetary gears is easily reminiscent of Toyota's THSII. In fact, they do have considerable similarities in basic principles. The two motors work together with the planetary gear set to achieve the purpose of changing the transmission ratio and power mixing. The difference is that Toyota's THSII focuses more on the direct output of the engine under normal driving conditions, while VOLTEC focuses more on the collaborative work of dual motors. With this system, VOLT's extended-range electric vehicle is fundamentally different from the popular plug-in hybrid electric vehicle. It is more like a set of deep hybrid technology with the addition of plug-in-like methods. Not only was it not available at the time, it is also very rare now. The technology used on Buick VELITE5 is basically the same as the second-generation Chevrolet VOLT, and even goes further. In fact, it was based on the development of the first-generation VOLT that GM began to gain experience in deep hybridization, and then applied it to the development of the new-generation extended-range electric vehicle Buick VELITE5. GM's new hybrid system is equivalent to adding a planetary gear set to the previous VOLT hybrid, thus forming the effect of dual planetary gears + dual motors working together. Among the dual motors, one is the "main drive motor", and the other is responsible for the task of "generator" in urban congestion and other road conditions. When needed in smooth traffic conditions, it can directly participate in vehicle driving to avoid "oil-to-electricity" process, thus making up for the shortcomings of the previous range-extended electric vehicles’ reduced efficiency under high-speed conditions. It is worth mentioning that among extended-range electric vehicle products, Chehejia’s Ideal ONE will be more competitive from a product perspective for the following reasons: First, as the former founder of Autohome, Li Xiang founded The first SUV product after Chehejia, I think Li Xiang is a person who knows how to build and wants to build good products; secondly, "Ideal ONE" can be said to be the pure electric vehicle with the highest cruising range that has been mass-produced. , solves the much-talked-about battery life problem (although it is an extended-range version); third, Ideal is the most complete mass-produced pure electric vehicle so far (which is good news for consumers); fourth, As a luxury seven-seat SUV, the ideal price is indeed one of the lowest in its class. The editor has said that the positive significance of program extension to the development of the new energy industry has three aspects: First, market recognition. In the short and medium term, it can meet consumers' different travel scenarios, has a high market acceptance, and can promote the popularization of pure electric vehicles; second, the technology is close to pure electric vehicles. Due to the long mileage of extended-range pure electric vehicles, it is necessary to invest heavily in many technical propositions such as battery management, lightweighting, thermal management, and electric drive. These technologies are common to pure electric vehicles and are conducive to technology accumulation; thirdly, charging basics Facility expansion. Plug-in hybrids, including extended-range models, also require charging. With the promotion of plug-in hybrids, the construction of charging infrastructure will continue to drive the construction of charging infrastructure, thereby laying the foundation for pure electric vehicles. In terms of market practicability and products, I believe that “extended-range electric vehicles are the product that is most compatible with the past and the future between traditional fuel vehicles and future pure electric vehicles. They will inherit the advantages of the traditional automobile industry to the greatest extent without destroying traditional automobiles too much.” Under the premise of the industrial chain, together with the gradually mature battery energy storage technology, the whole society will be slowly promoted to the stage of pure electric vehicles.
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