Technical support
Since 2016, benefiting from the explosion of the new energy vehicle market, the total investment in power lithium batteries has reached nearly 50 billion yuan. Contrary to the frenzied influx of capital into the power lithium-ion battery market, 3C consumer electronics has made very little public capital investment in lithium-ion batteries, especially in the mobile power supply market, which has always been unpopular with capital. Chaotic and disorderly competition continues, price wars continue to be tried and tested, and the homogenization of products and channels is becoming more severe.
In the 2014 annual report on mobile power, it was mentioned that there were over 5000 manufacturers of mobile power, mostly small and micro enterprises. In 2014, the entire mobile power industry ushered in an era of industry integration, with the number of mobile power production enterprises suddenly decreasing from 5000 to around 500 by the end of 2014. In addition, the national mandatory standard for mobile power supply in China - "Safety Requirements for Lithium ion Batteries and Battery Packs for Portable Electronic Products" - was officially implemented on August 1, 2015. Industry insiders expect that with the implementation of mobile power industry standards, the entry threshold for the mobile power industry will gradually increase, and a large number of small and micro enterprises that do not meet the standards will be gradually eliminated. The entire industry will achieve standardized development through survival of the fittest, mergers and acquisitions.
The 2014 China Mobile Power Market Research Report jointly released by CCID Consulting and China Battery Network shows that the mobile power market size from 2011 to 2014 was 3.4 billion yuan, 5.8 billion yuan, 10.5 billion yuan, and 16.5 billion yuan, respectively. CCID Consulting and China Battery Network predict that the domestic mobile power market size will reach 22 billion yuan in 2015, a year-on-year increase of 51.72%, and the overall market size will reach 32 billion yuan in 2016. The growth rate of the mobile power supply market in the next two years will gradually become rational, and the standardized development of the industry will gradually stabilize the growth rate of the mobile power supply market.
At present, large capacity and ultra large capacity have basically become the mainstream configurations of mobile power supplies. In addition to pursuing an increasingly large battery capacity and a lightweight and compact appearance, the length of charging time and the total amount of electricity that can be released are also key concerns for consumers when choosing mobile power sources. To produce products that are recognized by consumers, technical support is required. At present, the competition mode of Chinese enterprises still remains in price wars, with a lack of process design and quality control capabilities for mobile power supplies, often taking a low-end route. Price wars result in insufficient profit margins throughout the entire industry chain and the inability to invest in product research and development. Therefore, if enterprises want to win in market competition, they cannot rely on price wars, but must attach importance to technological research and development and industrial design.
The power module combines most of the necessary components to provide a plug and play solution, replacing over 40 different components. This integration can simplify and accelerate system design, and it can also significantly reduce the circuit board area occupied by the power management section. In order to achieve the required voltage accuracy, these power modules are generally placed on the circuit board near the chip circuit that needs to be powered. However, as the complexity of the system increases, layout becomes more important in systems with larger currents, lower voltages, and higher frequencies.
*The common isolated power module is a single in line package (SIP) and open shelf structure. They can obviously bring convenience to engineers and simplify system design. However, generally speaking, they are only suitable for designs with lower switching frequencies, such as 300kHz or lower. Furthermore, their power density is often not optimized, especially compared to DC/DC chip level modules.
The isolation of power modules is generally divided into two types: one is the isolation between input and output; The input and output are not in common; Another type is isolation between outputs; Multiple sets of outputs are isolated from each other and do not interfere with each other.
With the development of conductor, especially semiconductor technology, packaging technology, and the widespread use of high-frequency soft switches, the density of power modules is increasing, and the conversion efficiency is also increasing. Applications are also becoming simpler and simpler. The direction of development is to make the power supply lighter, smaller, thinner, with lower noise, higher reliability and anti-interference.
The working process of the power module is very special, and the working sequence and voltage increase are divided into three stages. Stage 1 is the rectification of 380V AC power to 400VDC, Stage 2 is the detection of 400VDC, and continues to charge the DC LINK capacitor to 570VDC. Stage 3 is waiting for a pulse enable signal to appear, increasing the DC LINK voltage to 600VDC. Due to the simultaneous provision of start, drive enable, and pulse enable signals, the above three step interval time is extremely short. The IGBT rectifier bridge starts working as soon as the enabling conditions are met. When the IGBT rectifier bridge and pulse distribution circuit experience high current breakdown or pulse order disorder due to voltage instability, humidity, dust accumulation, and other reasons, the surge current impacts the IGBT DC side of the coordinate axis power module through the DC bus, This is the fundamental reason for the short circuit and burning of the power module. When the IGBT rectifier bridge is short circuited, the incoming reactor should play a certain protective role in preventing the current from rising too fast. The decrease in insulation capacity leads to a sharp decrease in inductance, which cannot effectively protect the power module. This is also the secondary reason for the burnout of the power module.
The normal supply range of voltage in China is 380 (1-15%) V-380 (1+10%) V AC. The voltage requirement of the Siemens power module is 380 ± 5 V AC. When the power supply exceeds the voltage required by Siemens, the self-protection function (fuse) of the power module will be lost, and the fuse and three associated electrical components will be broken, resulting in the power module being burned out.
A power module is a power supply that can be directly mounted on a printed circuit board. Its characteristic is that it can provide power for specialized integrated circuits (ASICs), digital signal processors (DSPs), microprocessors, memory, field programmable gate arrays (FPGAs), and other digital or analog loads. Generally speaking, this type of module is called a Point of Load (POL) power supply system or a Point of Use Power Supply System (PUPS). Due to the many advantages of modular structure, modular power supplies are widely used in communication fields such as switching devices, access devices, mobile communication, microwave communication, optical transmission, routers, and automotive electronics, aerospace, etc.
In the field of switching power supply technology, people are developing related power electronic devices while developing switching frequency conversion technology. The mutual promotion of the two promotes the development of switching power supply towards light, small, thin, low noise, high reliability, and anti-interference with a growth rate of over two digits each year. Switching power supplies can be divided into two categories: AC/DC and DC/DC.
Micro Low Power Switching Power Supply
Switching power supply is moving towards popularization and miniaturization. Switching power supply will gradually replace all applications of transformers in life. The application of low-power micro switching power supply should first be reflected in digital display meter, smart meter, mobile phone charger, etc. At present, the country is vigorously promoting the construction of smart grids, and the requirements for energy meters have significantly increased. Switching power supplies will gradually replace transformers in the application of energy meters.
Reverse series switching power supply
The difference between a reverse series switching power supply and a general series switching power supply is that the output voltage of this reverse series switching power supply is negative, which is exactly opposite to the polarity of the positive voltage output of a general series switching power supply; And because the energy storage inductor L only outputs current to the load when the switch K is turned off, under the same conditions, the output current of the reverse series switching power supply is twice that of the series switching power supply.
