The recent power curtailment in many places across the country has made more people's eyes focus on the "energy" issue.
Behind the power curtailment, it is mainly caused by the fluctuation of the cyclical supply of traditional energy sources such as coal, and the final solution depends on optimizing the energy structure. This makes people look forward to the wide application of new and sustainable energy.
The good news is that we are already at the beginning of a magnificent new era of the "energy revolution".
Wind turbines in the countryside, photovoltaic power plants spread over the mountains, gradually climbing geothermal energy heating and cooling area, and more and more new energy vehicles on the street...
Just as only a few people perceived it in the embryonic period of the Internet, the beginning of such a new era of energy revolution may not be more deeply understood by most ordinary consumers, but our world has been quietly changed because of these buds.
The closest to our ordinary consumers may be new energy vehicles.
When it comes to new energy vehicles, it has been very popular in the past year to now.
According to data released by the Federation of Passenger Vehicles on October 12, the wholesale sales of new energy passenger vehicles reached 355,000 units in September this year, an increase of 14.7% month-on-month and 184.4% year-on-year. At the same time, the penetration rate from January to September has increased to 11.6%.
In this context, more and more consumers are turning their attention to new energy vehicles. Most of the various topics discussed by everyone are actually related to a system, that is, the three-electric system.
The three-electric system is the core of new energy vehicles, or electric vehicles, which includes three parts: battery, motor and electronic control. Whether from the technical level or the industrial level, the three-electric system is the most critical feature of the new energy vehicle that distinguishes it from the traditional fuel vehicle, whether it is to buy a car or understand the new energy vehicle, it is necessary to start from the three-electric system.
Today, IT Home will explain in detail what is the mystery of the "three electricity" of new energy vehicles.
First, the battery
The battery is definitely the most concerned about the "three electric systems" of new energy vehicles, which largely determines the endurance of new energy vehicles. Generally speaking, the power battery capacity and energy density are the main factors affecting the mileage of the whole vehicle, and everyone buys a car mainly to see it.
The power battery we are talking about refers specifically to the high-voltage battery that provides a source of power for the whole vehicle, and there are usually several low-voltage batteries on new energy vehicles.
▲ Photo from: Ningde times official website
In the power battery, the battery cell is the most important, which is composed of four major materials: positive electrode material, negative electrode material, diaphragm, and electrolyte.
At present, the basic lithium batteries used in new energy vehicles are lithium batteries, and what nickel-metal hydride batteries and lead-acid batteries were used before are now almost eliminated.
1. Cathode material
The cathode material of the four major materials of the battery cell is to provide lithium ions for lithium batteries, which is related to the energy density, life, safety, etc. of the battery, and the cost accounts for 40% of the entire power battery, which is the most.
At present, there are four main cathode materials on the market: lithium iron phosphate, lithium manganate, lithium cobalt oxide and ternary materials.
If you pay attention to new energy vehicles, I believe you will often hear these words. However, before introducing these materials, IT Home also needs to say a technical term: than energy.
Earlier we said that the energy density of the battery is the main factor affecting the endurance, and the specific energy of the positive and negative electrode materials is the main factor affecting the energy density of the battery.
Specific energy is the amount of electrical energy that can be released per unit mass of electrode material (sometimes specific energy is also understood as energy density). The higher the specific energy of the positive and negative electrode materials, the higher the battery energy density and the longer the battery life.
Back to the four cathode materials of the battery, the first three are various chemical elements, and what is the last ternary material? In fact, it is made of three different chemical elements, mainly nickel cobalt manganese NCM and nickel cobalt aluminum NCA.
The characteristics of each of these four cathode materials are shown in the following table:
What are the current applications of these battery materials? From the following figure, it can be seen that ternary cathode materials and lithium iron phosphate batteries are currently in the mainstream position in China, and it is also a trend of future development.
Ternary material batteries win in the specific energy, low cost, the use of this battery of the car generally in the mileage has an advantage; and lithium iron phosphate battery advantage is high safety, long life, and the price is lower than the ternary cathode material battery, the disadvantage is smaller than the energy, poor endurance, poor cold resistance.
A more typical example is the previous Tesla Medel 3, the imported version of the 53KWh capacity ternary lithium battery mileage (480KM) is longer than the domestic class mileage (468KM) of the 55KWh lithium iron phosphate battery, which fully illustrates the advantages of the ternary lithium battery in terms of endurance.
However, the advantages of lithium iron phosphate batteries in terms of safety are also more obvious. In the battery acupuncture experiment that BYD has officially demonstrated, three
Meta (parameter | picture) Lithium batteries burn violently after being punctured, while ordinary lithium iron phosphate batteries have smoke and no open flame on the surface after being punctured, and the temperature is only 200 °C-400 °C. In extreme cases, it is critical that the battery is able to not burn or explode.
BYD's blade battery performs better, with almost no obvious reaction after being punctured, smokeless and open flame, and the surface temperature is only 30 °C-60 °C.
Blade batteries are a "manifestation" of the evolution of lithium iron phosphate battery technology, and similar to the "CTP" batteries of the Ningde era, both of which are superior, not to mention, but they all have a common direction of effort, that is, to improve the energy density of lithium iron phosphate battery packs, thereby improving endurance.
The two ideas are similar. In the past, we had to make batteries into modules, and then put them together to form battery packs, which took up space.
Just like some snacks have a large package on the outside, there are many small packages inside, and there are not many that can be eaten in the mouth in the end.
The way to increase density is to reduce or even remove the module. The method of "CTP" batteries in the Ningde era is to make the battery larger, the module is less, the module itself occupies less space, and the energy density can be improved.
Blade batteries are directly removed from the module, the battery is made as thin as a blade, and then stacked horizontally, so that these batteries can not only generate electricity, but also support the overall architecture of the battery pack (the module originally played the role of supporting architecture). Because the module is gone, it is full of batteries, the density will naturally go up, and the endurance can also be improved.
Of course, these technologies only improve the endurance from the structure, and the improvement effect is relatively limited, but combined with other advantages, the future prospects of lithium iron phosphate batteries are still optimistic, and it is also one of the key bet directions for many domestic battery factories.
As for lithium cobalt oxide and lithium manganate, they are not often used in the power batteries of new energy vehicles. Lithium cobalt oxide, because of its poor thermal stability, is less suitable for use as a car power battery, and is more often used in the field of digital 3C, the early Tesla
Roadster (parameter | image) was used.
Lithium manganese oxide is a relatively traditional power battery cathode material, energy density, thermal stability, life and other aspects of the performance are relatively general, in the past for Japanese and Korean car manufacturers to use, and now gradually fade from the mainstream.
The above cathode materials, the mainland can be independent supply, domestic enterprises such as Shanshan shares, China Baoan and other enterprises, in the production of cathode materials have enough competitiveness.
2. Anode material
The negative electrode material is used by lithium batteries to carry lithium ions and electrons during charging and discharging.
The process of charging a lithium battery is that the lithium ions in the lithium compound pass through the film from the positive electrode to the negative electrode, and the thin film is equivalent to a filter paper, allowing only the ions to pass through, not allowing electrons to pass through. Electrons can only reach the negative electrode from the positive electrode via an external circuit.
Why don't electrons pass through? Because if the electron passes directly through the film from the positive electrode to the negative electrode, a short circuit will be formed, so won't the battery explode in place?
Finally, lithium ions and electrons converge at the negative electrode to form a storage of electrical energy.
When discharging, in turn, lithium ions pass through the thin film from the negative electrode back to the positive electrode, and the electrons still have to go to the outer circuit, and when they pass through the outer circuit, a current is formed, which is equivalent to discharge. Lithium ions and electrons finally reunite at the positive electrode.
In both processes, the anode material plays a role in the storage and release of electrical energy.
At present, the most mainstream anode material for new energy vehicle power batteries is artificial graphite. Artificial graphite belongs to graphitized carbon materials, graphitized carbon materials have the difference between natural graphite and artificial graphite, artificial graphite because of the specific energy, cycle life, magnification and other aspects of comprehensive advantages, so it is now the mainstream choice.
▲ Artificial graphite, pictured from the official website of Jiangxi Zichen
In addition to artificial graphite, there is also a negative electrode material with high future prospects, that is, silicon carbon anode material.
Silicon carbon anode materials have a significant advantage in terms of specific capacity. The theoretical maximum specific capacity of artificial graphite is 370mAh/g, and the specific capacity of silicon-carbon anode materials can theoretically reach a maximum of 950mAh/g, which is very helpful for the battery life.
Tesla is already there
Model 3 (parameter | picture) uses a part of the silicon carbon anode material, which is widely used in this material, and it will take a while, and we can expect to use this anode material in electric vehicles in the future.
In terms of industrial chain, the current global production capacity of anode materials is basically concentrated in China, and our market share in 2018 has reached 73.4%. Only one of the top five companies in the world is from Japan, and the rest are Chinese companies. In China, the leading enterprises producing anode materials are represented by the three leaders of Beiterui, Shanshan Shares and Zichen Technology.
However, although the production capacity is concentrated in China, we still have weaknesses in the production of anode materials, such as needle coke, one of its important raw materials, which mainly relies on imports, especially the autonomy of high-end needle coke still needs time.
3. Diaphragm and electrolyte
The diaphragm is the layer of "filter paper" that allows lithium ions to shuttle back and forth and block electrons and other particles in the principle of charge and discharge of lithium batteries earlier.
The diaphragm can be divided into dry diaphragm and wet diaphragm according to the production process. Dry separators are mostly used in lithium iron phosphate batteries, and wet separators are mostly used for ternary lithium batteries.
▲ Diaphragm, pictured from Shanghai Enjie official website
At the same time, wet process technology is generally used in high-end diaphragm products, and the overall performance of wet diaphragm is significantly higher than that of dry diaphragm, which is the main trend in the future. At present, the mainland has a good breakthrough in wet diaphragm technology, and domestic substitution is underway.
As for the electrolyte, it acts as a carrier for ion transport between the positive and negative electrodes in the battery. Among the four major materials of power batteries, the domestic industrial development of electrolyte is the most mature.
Second, the motor
1. Motor type
The motor refers to the drive motor of the new energy vehicle, that is, the motor. It is equivalent to the engine of a traditional fuel vehicle, converting the electrical energy of the battery into mechanical energy and is a direct source of vehicle power.
The principle of the new energy vehicle motor is a bit complicated, it is inconvenient to unfold here, it is mainly composed of stators, rotors, casings, connectors, resolvers, etc., of which the stator and rotor are the most important.
The drive motors of new energy vehicles are divided into four categories according to the overall technology: DC motors, AC asynchronous motors, permanent magnet synchronous motors and switched reluctance motors.
Of course, according to the details of the technology to divide can also be divided into more categories, such as according to the drive mode can be divided into centralized motor and wheel type motor, here IT home is not much to expand.
Among the above four categories, DC motors have been eliminated, and switched reluctance motors are also very rare in electric vehicles because of noise and other reasons.
AC asynchronous motors and permanent magnet synchronous motors are the main motor types of new energy vehicles at present. Moreover, AC asynchronous motors are actually relatively rare now, mainly used in large-scale high-speed electric vehicles and European and American car series.
So as consumers, permanent magnet synchronous motors are the most common.
According to data from the Ministry of Industry and Information Technology, by June 2019, the share of permanent magnet synchronous motors in China's domestic drive motor market has reached 99%.
Just now we said that the key components of the electric motor are the stator and rotor. If you use one sentence to explain the principle of the motor, it is: the stator uses the rotating magnetic field generated after the power is energized to make the rotor run.
The difference between AC asynchronous motors and permanent magnet synchronous motors is the rotor. The rotor of the AC asynchronous motor is a wire, which needs to be driven by the principle of electromagnetic induction to run after the stator rotating magnetic field, and can never catch up with the speed of the rotating magnetic field, so it is called "asynchronous".
Well, how to say it, falling in love with a girl who can never catch her hand is this feeling.
The rotor of the permanent magnet synchronous motor is embedded in the permanent magnet, and there is no need for any electromagnetic induction and other steps. When the rotating magnetic field of the stator is generated, the permanent magnet also rotates synchronously. At this time, the speed of the rotor and the stator magnetic field is the same.
▲ Photo from: Head Leopard Research Institute
Just now it was a girl who fell in love with a girl who can never be chased, and this time it was a husband and wife, working together. It goes without saying which is better.
In actual use, the overall performance of the permanent magnet synchronous motor is indeed better, it has a high efficiency, but the cost is also relatively high. The EFFICIENCY OF AC asynchronous motors is relatively low, but the cost is also low, and there is an advantage, that is, good durability.
There is also a kind of called flat wire winding motor, it is for the stator winding, the traditional winding coil for a number of thin round lines, and the flat wire winding will become a flat rectangular wire, which can improve energy density, improve heating efficiency, while increasing power.
The process of flat wire winding motor is more complicated, and there are not too many applications at present, but the future trend of driving motors. There is currently a fourth generation on the market like Toyota discovered in 2015
Prius (parameter | image), Roewe
Models such as the Ei5 (parameter | picture) use motors of this technology.
2. Motor industry
At present, there are more than 30 manufacturers of new energy drive motors in China, and there are about 15 companies that can supply vehicle companies in batches.
In the past ten years of development and accumulation, the mainland in the development of new energy vehicle drive motors has made great progress, although in some parts of the industrial chain is still lagging behind the international top level, but as a whole has been able to achieve leadership, the core technology can be controlled independently.
It can be said that the development prospects of the mainland in the drive motor industry are still worth looking forward to. In terms of the domestic drive motor market pattern in 2020, among the top five installed companies, only Tesla is from abroad.
According to the situation of the top ten in the market, motor companies are mainly based on the three types of vehicle companies, third-party independent motor companies, and motor enterprises that are joint ventures between vehicles and three-party enterprises.
From the perspective of the upstream, middle and lower reaches of the industry, the upstream of the drive motor industry includes the supply of raw materials and components, the most important of which is the permanent magnet and bearings and bearing covers; the middle reaches of the industry can be divided into motor manufacturers, and the downstream is mainly for the main engine factory.
Upstream components, the most important raw material is Gerfeb permanent magnet, which is the third generation of rare earth permanent magnet materials. China has the world's largest reserves of rare earth resources, accounting for 36.7% of the world's reserves and 80.5% of the output, while the system processing and refining technology is also the international leading level. This is a major advantage of the development of the continental drive motor industry.
▲ Photo from: Head Leopard Research Institute
In terms of bearings and bearing covers, the relevant products of the mainland have certain competitiveness, but they are still for the special bearings for the drive motor of new energy vehicles, and the product research and development of the mainland in this regard is not perfect. Compared with international leading companies such as Sweden's SKF, Japan's NSK, etc., the gap in performance, durability, materials and other aspects is still relatively large.
Speaking of midstream motor manufacturing, at present, local manufacturers in the mainland have a good performance in core technology and manufacturing process, and can independently develop motor products required to meet the needs of various types of new energy vehicles; as for the downstream, China has emerged many new energy vehicle host enterprises under the influence of new car manufacturing forces, and China is the world's largest new energy vehicle market, which is also an important advantage.
Third, the electronic control system
If simplified, new energy vehicles can run with batteries and drive motors. But how to run, how to change speed, when to brake, how to climb the hill, etc., all the situations, there also needs to be a system to control, this is the electronic control system.
The electronic control system of new energy vehicles is the device that controls the motor drive of the car, which is equivalent to the brain of the new energy vehicle, and reasonably controls the operation and power output of the entire vehicle.
Compared with traditional fuel vehicles, the electrical system of new energy vehicles has changed dramatically, and the requirements for electronic control systems are higher and more complex.
The core components of the electronic control system of new energy vehicles include inverters, drives, power supplies, controllers, protection modules, heat dissipation systems, signal detection modules, etc., but the most core components are three: inverters, drivers and controllers.
Similar to the drive motor, the electronic control system industry chain is also divided into upstream, middle and lower reaches, the upstream is mainly a variety of electronic component suppliers, the middle stream is mainly system integration and manufacturers, and the downstream is a new energy vehicle main engine factory, which is our common variety of automobile brands.
In the entire industry chain, the most critical is the upstream component supply, here THE home focuses on the core module of the inverter in the "three major pieces" of the electronic control system: IGBT (insulated gate bipolar transistor).
This small power semiconductor device can be said to be the key to the electronic control system, and the cost can account for 40-50% of the entire electronic control system. And such an important component, how is our autonomy at present?
According to 2019 data, China's IGBT market suppliers are mainly occupied by foreign giants such as Mitsubishi, Infineon, Fuji, SEMIKRON, etc., about 90% of the products need to rely on imports, and the total share of the top five in the world can reach 74%. Especially in high-end and high-power IGBT products, Foreign leading enterprises such as Infineon and ABB of Switzerland have absolute advantages.
However, as far as the mainland is concerned, under the guidance of national policies and the efforts of domestic enterprises, the development of the IGBT industry has made great progress, the prospects for localization are not uncertain, and some enterprises have considerable strength.
For example, CRRC Times is the only enterprise in China that fully grasps the research and development, module packaging, testing and application of IGBT chips, and also has a strong strength in high-voltage IGBT products, and has achieved domestic substitution in high-speed rail and rail-to-rail traction converters.
In addition to the CRRC era, domestic BYD Semiconductor also has a strong strength in IGBT, they are the mainland's largest, and the only self-sufficient vehicle specification IGBT supplier, in terms of technology, their IGBT products in some performance has been comparable to international manufacturers, of course, the overall gap with top companies is still there. In addition, at present, their products are mainly self-supplied, and it is expected to increase the supply of external supply in the future, which obviously has a boost to the risk of breaking through the neck of the IGBT card in the mainland.
In addition, Star Semiconductor has also made a certain breakthrough in IGBT chips, and has now produced the sixth-generation chip FS-Trench of international standards, and in the first half of this year, their vehicle-grade IGBT modules have a total of more than 200,000 new energy vehicles.
▲ Picture from: Star Semiconductor official website
In the middle and downstream of the new energy vehicle electronic control system industry, there is not much risk, and the degree of autonomy in the mainland is relatively high. Among them, the middle reaches of the industry are mainly the manufacturing integration of electronic control systems, which are mainly composed of automakers such as BYD and BAIC BJEV and third-party integrators such as Shanghai Electric Drive, of which the vehicle manufacturers have occupied 50% of the market share.
In general, although there is still a gap between the mainland new energy vehicle electronic control system industry and the leading international enterprise giants in some aspects, it is not hopeless to catch up, and I believe that with the advancement of the wave of domestic substitution, we can gradually catch up and truly achieve self-sufficiency.
Fourth, the future
After reading the introduction of the IT home above, I believe that everyone can also find that the "three electricity" of new energy vehicles is very closely related to each other, especially the motor and electronic control, which are often put together.
In fact, "integration" is a core trend in their future development.
Integration, simply put, is to integrate the core components of the new energy vehicle three-electric system and even beyond into one piece, such as the motor and electronic control system switch devices, circuits, controllers, sensors, power supplies, etc. integrated into the standard module, forming an all-in-one system module, thereby improving the operational efficiency and traditional efficiency of the automotive electrical system, but also reduce weight, save space and cost, many advantages.
Everyone thinks, especially in the future, the car is becoming more and more intelligent, and there will definitely be more sensors and processor devices in the car, and integration is an inevitable road.
In terms of integration, the leading electronic control system suppliers in the industry such as INVT, Jitaike, Huichuan Technology and so on have achieved certain results, and there are already two-in-one, all-in-one electronic control system products in application.
What is even more exciting is that under this trend, we have also seen the figure of Huawei. In 2019, Huawei set up a smart car solution BU, although it does not build its own cars, it has provided technical support and product solutions for many automotive companies.
Now open the official website of Huawei Smart Electric, you can see that Huawei's main solutions include all-in-one electric drive system, three-in-one electric drive system, end cloud battery management system, motor controller, vehicle charger and DC fast charging module and other products.
Among them, Huawei's DriveONE all-in-one electric drive system and three-in-one electric drive system are product solutions that conform to the general trend of integration of new energy vehicles. Taking the all-in-one electric drive system as an example, it integrates seven major components of MCU, motor, reducer, DCDC, OBC, PDU and BCU, realizing the deep integration of mechanical components and power components. On the other hand, intelligence is brought into the electric drive system to achieve the integration of end-cloud collaboration and control.
Their DriveONE three-in-one electric drive system integrates a motor controller (MCU), motor and reducer, which can also bring high-density and efficient long-endurance driving experience to new energy vehicles.
According to the understanding of IT Home, Huawei's related solutions and products have been applied in models such as Cyris SF5, SAIC Maxus MAXUS EUNIQ5 and other models, in addition to LIKE ARCFOX αT, GAC Aion LX/Aion, etc. also use Huawei OBC products, ARCFOX Pole Fox also has more in-depth cooperation with Huawei.
In the field of new energy vehicles, Huawei mainly focuses on the directions of intelligent driving, intelligent cockpit, intelligent network connection, intelligent electric and intelligent vehicle cloud, and believes that with their advantages in software control algorithms, it can make better results in the direction of electronic control system and integration.
Finally, it is worth mentioning that the new energy three-electric system has a trend that cannot be ignored in terms of motors, that is, the hub (gǔ) hub drive.
Wheel hub motor we mentioned earlier, it is an important development trend in the future, the so-called wheel hub drive, simply put, is to install a motor in the wheel hub of the wheel, the transmission torque is directly transmitted to the wheel, so that it can be introspective for the body clutch, transmission and many other transmission components, improve the transmission efficiency at the same time, but also release the space of the car.
In general, the "three electric systems" of new energy vehicles in the future will generally move towards integration, digitalization and intelligence, which is not only the demand for the development of new energy vehicles, but also the trend of deep integration of advanced technology and energy revolution.
epilogue
In 2021, the new energy vehicle purchase subsidy standard has declined by 20% on the basis of 2020, but according to the data of Open Source Securities, the retail sales of new energy passenger cars in 1-8 months this year were 1.479 million units, an increase of 202.1% year-on-year, basically did not receive the impact of subsidy decline, which seems to indicate that the market-led wind direction is replacing the subsidy-led market in the past, and a new era of new energy vehicles is coming.
In this context, looking at the development of the "three electric system" industrial chain behind the new energy vehicles in the mainland, it is undoubtedly more important for us to look forward to the future development of the local new energy automobile industry.
In fact, around 2010, the mainland's development of the new energy vehicle three-electric system is still relatively backward, but for more than a decade, under the guidance of national policies and the efforts of core enterprises, it has caught up. Although there are still deficiencies at present, IT Home believes that just as we have persevered in the past, the future is not far from our real leadership in the new energy automobile industry.
disclaimer
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