Not long ago, the “Carbon Peak Action Plan by 2030” issued by the State Council pointed out that by 2025, the installed capacity of new energy storage will reach more than 30 million kilowatts. The “Guiding Opinions on Accelerating the Development of New Energy Storage” issued by the National Development and Reform Commission and the National Energy Administration earlier also clarified the development goal of energy storage: the installed capacity of new energy storage will increase from 3.27GW at the end of 2020 to 30GW by 2025. The five-year compound annual growth rate is about 55.8%. Various policies and industrial trends have shown that the construction of new domestic energy storage is growing rapidly in the “Beauty Era”.
According to market survey data, the global installed capacity of energy storage will still reach a new high in 2020, with new installed capacity reaching 5.3GW/10.7GWh, of which China and the United States both have new installed capacity exceeding 1GW. Energy storage is becoming an important starting point for achieving the goals of “carbon peak” and “carbon neutrality”. It is also an important means of stabilizing the power system, and it is a strong support for realizing and ensuring the operation of a new power system with a high proportion of renewable energy. In this regard, Wang Xingwei, Senior Marketing Manager of ADI’s China Product Division, said: “Whether it is distributed optical storage or centralized renewable energy storage synergy, the combination of energy storage and renewable energy is an inevitable trend of low-carbon development in my country and even the world. .”
“Wind-light energy storage”, “charging station energy storage”…, mature application scenarios promote the implementation of energy storage
New energy and clean energy have brought about tremendous changes in the process of energy generation, storage, transmission, and utilization, driving the development of new intelligent power transmission and distribution and energy storage technologies to provide safe, reliable, green and efficient energy power guarantee . In this process, after more than ten years of development, power storage has rapidly moved from laboratory to large-scale commercialization.
The application mode of energy storage in new energy, car charging, industry and life scenarios is becoming clearer and clearer
Energy storage plays an important role on both the grid side and the application side of new energy. The grid connection of new energy will inevitably affect the stability of the grid, such as the seasonality of wind energy, the periodicity of solar sunrise and sunset…In order to make better use of new energy, its volatility must be overcome, and energy storage systems can Achieve balance. It is said in the industry that the new energy reaching 15% or more will have a great impact on the stability of the grid, and 30% may be a red line. “To solve low emissions, we must develop green energy. How to make new energy safe and reliable to operate in the grid, energy storage is very important.” Wang Xingwei emphasized.
The development of energy storage applications to this day is not only the energy storage demand on the new energy grid side, from electric vehicle charging stations, industrial power supply energy storage to household energy storage, there has been a “multiple flowering” trend of accelerating landing. “Although many DC fast charging piles in charging stations have become popular at this stage, in the future, there will be multiple high-current, high-power-density DC piles working at the same time, in order to solve the reality of insufficient energy supply on the AC side and the coordination of multiple energy sources. The development plan and the installation of energy storage systems in DC fast charging stations for electric vehicles has become an industry consensus.” Wang Xingwei pointed out.
Considering the charging station scenario with multiple charging piles, the peak power that the grid needs to provide for peak charging may usually exceed 1 MW, which may cause the grid to collapse at multiple points, or require huge investment in improving transmission lines or centralized Power plants, greatly increasing the base load. “New energy power + energy storage + charging piles will form a diversified complementary energy power generation microgrid system. Under the control of the green energy cloud, the energy storage system acts as an intermediate balancer, which can effectively smooth the load impact on the distribution network and reduce The cost of the power distribution line of the charging station can also realize the spontaneous self-use of photovoltaics, the storage of surplus electricity, and the peak and valley arbitrage of energy storage, maximize the use of peak and valley electricity prices, and maximize economic benefits.” Wang Xingwei further explained.
Energy storage system promotes electric vehicle charging infrastructure construction
High-precision, 18-channel BMS solution, multi-dimensional energy storage system design
Both electric vehicles and energy storage are inseparable from the empowering role of the battery management system (BMS). “Common energy storage stations are equivalent to tens of thousands of batteries together, and are much larger than electric vehicles. Compared with electric vehicles, large-scale advancement of lithium battery grid energy storage technology requires more high performance, stability, and safety. Strict, the key role of high-performance BMS is indispensable.” Wang Xingwei pointed out, “ADI covers the entire process of energy generation, transmission, utilization and storage, and enables green energy through system and chip technology including battery BMS. Cloud makes the use of renewable energy more reasonable and realizes energy saving and emission reduction throughout the life cycle.”
From the perspective of BMS, electric vehicle battery packs and energy storage battery packs are essentially the same. The difference is that the voltage level of electric vehicles is basically 300 volts and 400 volts. Energy storage requires about 800 volts, and it may be 1000 volts in the future. Even to 1500 volts. As the voltage level increases, the voltage, stability, charge and discharge stability, and temperature changes due to heat become more critical. “Accurate and reliable battery state of charge (SOC) and state of health (SOH) calculations can extend the battery life by 10 to 20 years. Therefore, BMS does not only provide some rough summary values, but needs to calculate the internal module Accurate measurement of large amounts of data and system temperature is essential for the charging, discharging and monitoring of battery packs.” Wang Xingwei pointed out, “For this reason, ADI China Products Division has launched a high-precision 18-channel battery management chip ADBMS1818 for industrial energy storage. , A system design optimized for energy storage applications.”
As a multi-cell battery stack monitor, ADBMS1818 can measure up to 18 battery cells connected in series. It has a battery measurement range of 0~5V, and the total measurement error is less than 3.0mV, which is suitable for most chemical battery applications. “Because the ADBMS1818 can measure all 18 battery cells within 290 μs, it can support a single chip for battery modules like 50V. For energy storage application scenarios, multiple ADBMS1818 devices can be connected in series to monitor a long high voltage at the same time. Battery string.” Wang Xingwei emphasized. In addition, in order to reduce system noise before affecting the BMS performance, ADBMS1818 integrates a 16-bit Σ-Δ ADC, and also presets a programmable noise filter, which greatly reduces the impact of electromagnetic interference and other transient noise.
It is worth mentioning that in the system of large battery packs arranged in battery packs or module groups, many applications require battery balancing to solve the performance differences caused by various factors in the aging process of different battery cells, such as battery packs. Differences in temperature gradients, premature aging of battery cells that exceed the upper limit of SOC cause loss of extra capacity, etc. These differences, as well as small differences in self-discharge and load current, will cause battery imbalance. “For overcharging or undercharging, passive balancing can be used to solve the problem of battery imbalance. ADBMS1818 can provide a passive equalization capability of 200mA. In addition, ADBMS1818 has 9 general-purpose digital I/O interfaces that can be used as temperature measurements. These functions are combined A single chip completes all the detection functions of a battery pack. If these data are sent to the management unit of the entire battery rack, the design of each battery pack will be greatly simplified.” Wang Xingwei added.
The modular design of current battery packs on the one hand increases the scalability, service capabilities, and flexibility of external dimensions, and on the other hand requires electrical isolation for the data bus between the battery packs. In addition, the wiring between the battery packs must be able to withstand high levels of electromagnetic interference. An isolated twisted pair data bus is a viable solution that can achieve these goals in a compact and cost-effective manner. Different from the traditional daisy chain communication structure, ADBMS1818 integrates an isolated SPI interface. The communication with the SPI master controller is through the ADI LTC6820 isoSPI to SPI signal converter, which realizes long-distance high-speed communication without RF interference. The two-way data transmission required for SPI communication is realized between fully electrically isolated devices. “In this way, the battery packs are formed into a very safe and reliable blockchain form. The stacked analog front-end can perfectly realize the construction of various energy storage systems. This stackable multi-cell battery monitor will physically Loss, the controller can read the data of each chip through the isolation SPI, which increases the reliability of the entire battery management system.” Wang Xingwei said.
The ecology of the lithium battery industry continues to be optimized, and the implementation of energy storage applications will continue to accelerate again
Industry data analysis shows that the cost of photovoltaic power generation has fallen by 89% in the past ten years, and nearly 80% of the country’s photovoltaic power generation costs are already lower than coal. With the promotion of the industrial chain brought about by the outbreak of electric vehicles, battery costs will continue to decline, and the cost of photovoltaic + lithium battery energy storage will continue to decline. According to GTM data, the cost of electrochemical energy storage power plants dropped by 78% from 2012 to 2017. The industry predicts that the cost of energy storage will drop to 1,000 yuan/kWh by 2030, and the combination of solar storage in most areas of my country can achieve parity. At present, energy storage power stations built with lithium-ion batteries based on lithium iron phosphate batteries have been established in Zhejiang, Hunan, Jiangsu and other provinces.
In addition, with the rapid advancement of the electric vehicle market, relevant studies have shown that the power batteries of my country’s first batch of new energy vehicles are fully ushering in the “retirement period”. The total weight of retired power batteries will exceed 800,000 tons. “When the charging capacity of a car’s lithium-ion battery drops to 70% to 80% of its initial capacity, it can no longer provide power to the car. But in fact, these batteries are not without electricity, and can still be used in energy storage and other fields. Achieve a life span of 5 to 10 years.” Wang Xingwei said when referring to the echelon utilization of retired batteries for electric vehicles.
When it comes to echelon utilization, we have to mention the “New Energy Storage Project Management Specification (Interim) (Draft for Comment)” issued by the National Energy Administration not long ago. This document requires key breakthroughs in battery consistency management technology and power battery performance. Before the monitoring and evaluation system is complete, in principle, no new large-scale power battery cascade utilization energy storage project shall be built. Due to the lack of “battery consistency management technology” and the absence of “power battery performance monitoring and evaluation system” in current decommissioned batteries, the use of recycled batteries with inconsistent characteristics and lack of authoritative monitoring for energy storage applications has great hidden dangers.
“ADI has noticed this problem very early. For this reason, we have launched a wireless BMS (WBMS) to solve this problem. We and the China Electric Vehicles Association initiated the establishment of the “Battery Full Life Cycle Joint Innovation Center”. Unite battery manufacturers, automakers, charging and swapping infrastructure providers, battery cascade utilization manufacturers and other upstream and downstream enterprises in the industry chain, based on wireless BMS technology to jointly achieve continuous monitoring of the key characteristics of the battery, the core component of electric vehicles, to achieve more accurate, Safe battery life cycle management provides important data support for the collaboration of related industry chain companies.” Wang Xingwei pointed out. According to the concept of the Innovation Center, all batteries based on WBMS technology can continuously collect battery data and realize cloud storage throughout their service life. These data provide accurate and authoritative data for the entire industry ecology, including used car transactions and retired battery echelon utilization.
ADI’s wireless BMS monitoring solution can cover the full life cycle monitoring of electric vehicle batteries
At present, ADI’s wireless BMS technology has been adopted by many well-known vehicle companies including GM, and the energy storage BMS solution has also been widely used in the industry chain including Chinese companies. “ADI has now set the corporate strategic goal of achieving carbon neutrality by 2030 and achieving net zero emissions by 2050. To achieve this goal, it is necessary to consider low-carbon innovations in multiple links such as production processes and processes, and to cooperate with third parties. Cooperation, exploring new solutions with customers through proprietary green technology, undoubtedly new energy power generation, energy storage, and electric vehicles will be the main directions for us to make important contributions to a green planet.”