Directory of problems
1. What is the prospect of the new mode of the extended range electric vehicle in new energy vehicles?
2. What are the configuration methods of the extended range electric vehicle?
3. Under the impact of the current hot spots such as the rapid increase in energy density of power batteries and the continuous decline in cost, what are the technical routes development opportunities of the extended range electric vehicle?
4. What are the characteristics of the DSM range extender?
5. Which vehicle has been installed and used in the DSM range extender?
1.What is the prospect of the new mode of the extended range electric vehicle in new energy vehicles?
Since 2014, the state and local governments have begun to subsidize the cost of batteries for new energy vehicles, especially for pure electric vehicles. As a result, a number of excellent new energy vehicle companies have emerged in China, and the luxury pure electric vehicle market represented by Tesla has developed rapidly in the international market. Among them, the mileage of new energy vehicles and the availability of charging facilities are the key to the development of the market, which need a lot of government subsidies to maintain development.
With the rise of the new energy vehicle market, the government's subsidies for pure electric vehicles began to decline year by year, and the subsidies will end by 2020. This makes the biggest disadvantage of pure electric vehicles - short driving distance, high price, charging construction lag three major problems are particularly prominent, will make consumers to buy pure electric vehicles are discouraged, lost commercial conditions.
Under such a policy background, the technical advantages of the extended range electric vehicle will gradually surpass the pure electric vehicle, and become the first choice for the commercial development of the new energy vehicle as the pure electric drive vehicle. According to the national regulations, the new energy vehicle production qualification can only produce pure electric vehicles and extended-range pure electric vehicles. Under the increasingly harsh commercial environment of pure electric vehicles, extended-range pure electric vehicles will become the core technology and products of new energy vehicle factories.
2. what are the configuration methods of the extended range electric vehicle?
The configuration route of the power system of the extended-range pure electric vehicles is determined by the ratio of the following three factors:
* Rated power of range extender (Pre)
* Rated power of driving motor (Pmot)
* Design pure electric total mileage (Rkm)
Based on the different proportions of the three factors, different configuration routes of different programs are formed.
Pre | Pmot | Rkm | Configuration | Notes |
1 | 1 | 50~80km | Mixing range extending | Comprehensive mileage is unlimited, oil is the main. |
1 | 1 | 150-200km | Electric power range extending | Comprehensive mileage is unlimited, electric is the main. |
＜0.7 | 1 | 120~150km | Electric power range extending | ＞500km，Strong auxiliary range extension |
＜0.5 | 1 | ＞100km | Auxiliary range extending | ＞400km，Light auxiliary range extension |
＜0.3 | 1 | ＞100km | Replenish electricity range extending | ＞300km，Vehicle load assisted charging |
Note:
1. The power contrast coefficient is between Pre and PMOT;
2. The main factors affecting the choice of different configuration are vehicle cost and space limitation.
3. Under the impact of the current hot spots such as the rapid increase in energy density of power batteries and the continuous decline in cost, what are the technical routes development opportunities of the extended range electric vehicle?
The development of power batteries is the foundation of the development of pure electric vehicles. The new generation of power batteries represented by lithium-ion batteries is the key and starting point of the development of pure electric vehicles. Although the construction of charging facilities has a long cycle, huge investment and slow effect, it is indeed the basic guarantee for the commercialization and sustainable development of electric vehicles. At present, the national government has given a great deal of subsidies and support to the development and production of lithium batteries and the construction of charging piles, which is of great significance to the development of new energy automobile industry.
However, lithium-ion batteries currently mainly use lithium-manganese-rich ternary materials to improve energy density. There is no substantive breakthrough in technology. Most of the lithium-ion batteries trade for high energy density at the main cost of sacrificing cycle life. The decline in battery prices can be achieved only under the conditions of squeezing the profits of manufacturers. Nowadays, the known new lithium battery technologies in the world include lithium-sulfur battery, lithium-air battery and solid-state lithium battery, which represent the mainstream of power battery technology. The cycle of industrialization and commercialization of these new technologies is likely to be long, with the possibility of commercial use expected in 10 years'time, or even longer. But the development of new energy vehicles can not wait for the development and maturity of these technologies, and whether the cost and time to achieve industrialization conditions have too many unknown risks. (For example, nanolithium batteries, which appeared 7-8 years ago, were not commercially available, and eventually the U.S. A123 went bankrupt and sold to China Wanxiang). At this time, the extended-range pure electric vehicle has become one of the indispensable paths in the development of new energy vehicles.
On the other hand, the fast charging of pure electric vehicles can not be popularized due to the limitation of grid capacity, so the charging pile can only be chosen to charge slowly. And parking charging is always the defect of pure electric vehicles, which is not be changed by the increasement of battery energy density. What should not be overlooked is that China's parking space resources are extremely scarce, and the chances of finding a parking space with charging piles and being able to park there for a long time to recharge may be slim. At this point, it can be a good choice to the extended-range electric vehicles that can be charged while walking.
Extended-range generation for extended-range electric vehicles is not necessarily high emission. At present, the range extender is mainly burning oil, because the fuel engine technology is mature and the price is cheap. Increasers using alternative fuels - methanol engines are already being developed and tested, and the future is that the emissions generated by charging while walking are almost negligible, while hydrogen fuel cell extenders will eventually become the ultimate extenders to achieve zero emissions.
From the point of view of technology development, extended-range electric vehicles technology is the only technology that can be seamlessly docked with pure electric vehicles and hydrogen fuel cell vehicles in the future.
4. what are the characteristics of the DSM range extender?
The competitiveness of DSM's range extender of energy products in the new energy vehicle market includes two aspects:
A) Compared with permanent magnet synchronous generator, doubly salient DC generator technology has the characteristics of simplicity, reliability, high efficiency and low cost, which makes it possible to obtain low cost, high efficiency and reliable products in the development of extender.
i. The doubly salient DC generator technology does not require inverter, so the generator system (generator + controller) is small and reliable.
ii. Based on modular design, generator/system controllers can be compatible with different power extenders to achieve a platform-based product line (the same electrical interface, the same communication protocol).
iii. Around the application of this technology has been a number of invention patents, to ensure the sustainable development of technology and market leader.
B) Platform modular system integration technology enables generators to adapt to any different engine products, with the advantages of shorter development cycle of extenders, simple and rapid vehicle integration, greatly shortening the development cycle of the vehicle. The products are mature and stable.
C) Around the application of extended range power generation system, a perfect auxiliary system for on-line parameter calibration, debugging and monitoring is developed, which has perfect supporting functions around the guarantee and after-sales requirements. The range extender system has been obtained by the state for strong inspection and filing, which can meet the emission requirements of national level V.
D) The technology development team from North America introduced the North American New Energy Vehicle Power System Integration technology, which is based on lithium-ion battery integrated group technology and dominated by hybrid system integration technology. The extended range power generation system is developed to optimize vehicle performance under operating conditions, taking into account both power generation efficiency, operating noise and exhaust emissions. At the same time, it can effectively prolong the working life of vehicle-mounted power batteries, and has the international leading level of development and intellectual property rights in the field of integrated development of extenders.
5. Which vehicle has been installed and used in the DSM range extender?
DSM's range extenders are currently being installed and tested on a variety of vehicles, of which the SUV has entered the announcement testing process. The parameters and performance of several test cars are given in the following table.
6. what is the development process of the extended range electric vehicle?
There are three situations in the development of extended range electric vehicle: pure electric vehicle after loading, pure electric vehicle adding, and new development of pure electric vehicle.
A. Pure electric vehicle after loading
This situation usually does not change the layout of the vehicle, but rather to find additional space available to add the range extender. At this time, space constraints are mostly limited to install a smaller power range extender to supplement the power (supplementary extension), such as an 8 kW extender. The direct effect of the extended range is not obvious. The goal is to temporarily supplement the battery or increase the mileage by 50~80 kilometers.
This is because the power of the extender is generally about 10-20% of the maximum power of the drive motor (equivalent to installing a car charger), generally do not need to announce.
B. Pure electric vehicle adding
This is the use of traditional fuel chassis development of new vehicles (need to be announced), chassis development on the choice of the right power of the extender and leave the corresponding space (usually in the front silo), the development process is generally divided into three steps:
(1) Pure electric development and testing
Under the premise of reserving space to install the extender, the pure electric vehicle configuration is completed and the corresponding tests are carried out to record various performance indicators, such as NEDC single cycle energy consumption, total driving mileage, maximum speed per hour, vehicle weight and so on. The development cycle lasts about 3~5 months.
(2) Install range extender for phase 1 calibration and testing.
After completing the pure electric configuration and testing, the range extender is installed again for final calibration and testing. The control of the extender can be controlled independently by the extender (short development cycle) or by the vehicle VCU. The main calibration performances include: the SoC setting of the boot range extender, the range of the power generated by the extender corresponding to the vehicle speed required for noise management, the NEDC single cycle energy consumption and fuel consumption in the extended range mode, and the comprehensive driving range. This process takes 4~8 weeks.
(3) Bulletin on
The test results show that the standard test and emission test will be announced on the new energy vehicle after the pure electric mileage and comprehensive mileage reach the design goal. The whole test will take about 8 months, including OBD test.
C. New development of pure electric vehicles
This new chassis development new energy vehicle project, the installation location of the extender according to the vehicle structure optimization needs, such as BMW I3 is installed in the rear. In most cases, special customized extender is needed, and the control of the extender is mainly controlled by the vehicle controller VCU.
Other development processes with pure electric mounting process.
7. What are the main control functions and performance of the DSM range extender?
DSM extended range products support extended range GCU autonomous control and vehicle VCU control. In the GCU autonomous control mode (modularization), the vehicle integration only needs mechanical installation and electrical plug-in, does not need the entire vehicle VCU system adjustment, can automatically match with the power battery and vehicle controller (short development cycle).
At this point, the extended-range control system automatically provides the following control strategies and performance (relevant parameters can be calibrated online or remotely):
A. System start / stop management
(1) The startup control takes into account battery charging state SoC, battery temperature, battery overload, etc.
(2) Stop control takes into account battery charging state SoC, speed, power consumption and so on.
B. Power generation current management
(3) Three level power generation platform management, including zero power, half power and rated power.
(4) According to the battery temperature, power following and rated power generation are adopted to protect the battery when the temperature is too low or too high.
C. Power generation noise management
(5) Level 3 noise management, including engine idle speed, engine low noise speed, engine rated speed
(6) The ISG start / generator controller ensures that the engine stops when it stops.
D. Battery protection
(7) Low temperature start power generation, reduce battery load and prolong life when battery power is low.
(8) Overload start-up power generation can reduce the burden of batteries and prolong the life of batteries under similar overload and low-speed climbing conditions.
(9) The high temperature starts the electricity generation, reduces the battery load and the life extension under the overheating condition.
8. Is there any major policy risk in the extended range electric vehicle project?
A. The extended-range electric vehicle project has been seriously affected by the subsidy policy.
During the period from 2015 to 2017, the development of extended-model electric vehicles (EVs) was left unmanned and at a standstill, as subsidies were directed towards purely electric vehicles (with shorter cycles) and aimed at meeting the subsidy standards (with faster profits).
B. The range extended electric vehicle project is more suitable for the environment without subsidy policy.
(1) After the subsidy is reduced or stopped, more new energy vehicle developers will invest in the development of plug-in electric vehicles. The goal is to achieve a combination of long driving mileage, no charge facilities, a sharp reduction in battery usage relative to the driving mileage, while meeting the requirements of new energy vehicles, license priority, road rights and double points.
(2) Technological routes for plug-in range extended electric vehicles have been recognized by the government and the market, such as: new energy vehicle plants that have been approved for new applications only allow the production and sale of pure EVs and plug-in EVs; and new vehicle investment project specifications that categorize plug-in EVs independently and explicitly into new energy vehicles and plug-in hybrid vehicles. The force car is classified into the fuel vehicle, and further determines the status of the technology roadmap.
(3) The development of the range extended electric vehicle market is a typical market-driven demand that does not require any policy subsidies at all.
9. What is the view of power battery development and charging facilities development?
A. The development of power battery and its impact on the development of new energy vehicles is heavy
(1) Power batteries are currently dominated by lithium-manganese-rich ternary batteries, and the energy density of batteries is increased at the cost of sacrificing battery life without breakthrough. This is a typical example of a development to meet the national subsidy standards (which do not specify cycle life indicators), and once the subsidy is removed it is likely to be difficult to sustain development.
(2) The development of new power battery technology requires a lot of capital and technology investment. In the short term (5-10 years), there may be no commercial opportunities for lithium batteries with high energy density, low cost and long life.
B.Development of charging pile Market
Charging pile construction investment is huge, reaching a certain coverage rate, construction cycle is very long.
In China (where there are not enough parking spaces), the utilization of charging piles will be questioned, so the coverage of charging piles is not equal to the utilization rate.
In the case of insufficient charge pile coverage for a long time, the problem of "mileage anxiety" of pure electric vehicle is the main bottleneck restricting the development of commercialization of pure electric vehicle market, and the problem of low charge pile utilization caused by insufficient parking space will be worse.
