With ESG now in full force, governments and enterprises are looking to increase their use of green energy so as to achieve true net-zero carbon emissions. Apart from developing better ways to generate renewable energy, storage is also crucial. This has spurred discussion of developmental possibilities for verification and testing of energy storage systems (ESS). On that point, Chroma ATE recently held a seminar on "Mastering EV/Energy Storage Testing Technology: Moving Towards Energy Sustainability," to discuss this issue from multiple perspectives, i.e. industry trends, test and measurement technology, and energy sustainability.
@Energy storage systems and the renewable energy grid: undeniably interdependent and important
Chroma ATE especially invited Joe Lin, general manager of AnTek Certification Inc. (ATC) to share his thoughts on the topic of "energy storage system standards and trends." Lin cited research data stating that Taiwan's energy storage market is expected to exceed NT$20 billion in 2023 and NT$250 billion by 2030, showing the astounding business opportunities in this market. Lin also brought up what happened in Australia in 2016 as an example, as tornadoes caused major blackouts leaving thousands of homes without power. Thanks to its rapid establishment of ESS in 2017, Australia saved itself from subsequent blackouts. It is easy to see how the existence of the ESS contributes to the resilience of the renewable energy grid. And to take the concept a step further, we see how it can achieve other functions for the grid, such as frequency regulation, peak load shifting, or dealing with short-term supply and demand imbalances.
Jason Lin, Chroma ATE's deputy product manager, reinforced Joe Lin's remarks by further analyzing the composition of energy storage systems. Generally, these systems can be divided into three subsystems: the controller (control box), rack controller (string BMS) and battery module (including module BMS). Chroma ATE also observed that although energy storage systems show a fairly clear growth trend, the battery management systems (BMS) for energy storage are not as good as those for electric vehicles (EV). EV manufacturers have turned out to be quite dominant in this segment. Still, there is currently no obvious leader in energy storage BMS products, and competition is fierce.
@As energy storage BMS voltage moves towards 1500V, adjustments must be made to meet verification standards
Current energy storage systems mostly operate at 1000V, but in recent years, the market has seen the voltage limit raised to 1500V. This increased voltage has further driven the overall power density in the same 40-foot container up to 35%, bringing with it some reductions in system costs and even improved control over land costs. Jason Lin observes that at the recent China International Battery Fair (CIBF), they actually saw many industry operators exceeding 1000V.
While it is true that a 1500V energy storage system offers effective overall cost control, it also presents its own challenges. One such challenge is that the insulation design of the battery system must be improved to withstand harsh use environments. With the increased number of battery cells in the 1500V system, now totaling over 400 from the previous 300, maintaining cell consistency becomes all the more crucial. In addition, most systems in the market have been based on 1000V, so the experience of most operators is also limited to 1000V. After the systems are upgraded to 1500V, the entire BMS system and control system must be re-adjusted and operational experience must be accumulated anew. Only when the 1500V system is safe can it contribute to the sustainable development of the energy storage industry. According to Jason Lin's analysis, as early as 2020, the revised IEC 63056 had already specified safety requirements and tests for lithium secondary cells and batteries used in energy storage with a maximum DC voltage of 1500V. Such specifications give the industry a basic direction to follow. In addition, for lithium secondary cells and batteries used in industrial applications, IEC 62619 addresses safety requirements, while IEC 62620 specifies a series of tests for performance and durability. Other specifications include UL 9540 and UL 1973, which provide tests for a series of items such as environmental and physical conditions.
@PCS and AFC technologies are key, and their test specifications should not be overlooked
Evan Tsai, Chroma ATE's product director, gave a detailed classification of energy storage systems on the market. One example is the ESS used in campers, which have power of about 2kW or less and operate at voltages below 100V. Generally, residential systems are below 30kW, with voltage ranging between 300 and 800V. In industrial and commercial use, power is below 500kW and voltage is 1000V. The 1500V systems described earlier make up the level used in the power grid. Tsai also highlighted many of Chroma ATE's solutions, such as Chroma's Bidirectional DC Power Supply Model 62000D Series, capable of providing a maximum output voltage of 1800V with power ratings up to 540kW. It also supports automotive testing standards LV 148 and LV 123.
In addition, when discussing energy storage, one is bound to mention inverter systems, or what are known as power conversion systems (PCS). Tsai says that relevant test items can be divided into three categories: grid-tied performance, input and output characteristics, and protection characteristics, totaling 23 test items. Chroma ATE offers a complete testing guide for industry reference and provides the equipment customers need for testing.
Jason Lin added that automatic frequency control (AFC) is an issue often encountered in Taiwan's energy storage market. AFC capitalizes on the advantages of fast charge-discharge of energy storage systems, allowing the ESS to actively adjust charging and discharging in response to the fluctuating load of the power system. This helps maintain a stable power system frequency, and is suitable for power systems that use a high proportion of renewable energy. Lin emphasized, however, that the key behind the performance of such technology in terms of service performance measure (SPM) and average service performance measure (ASPM), is still determined by battery performance. For this also, an array of test items and equipment is available.
Overall, under the impetus of renewable energy and ESG, there is marked development in the power grid system and low-power ESS markets. This has created a growing demand for measurement and verification, while also requiring a balance between safety and performance. Specifications are already in place and available for industry reference. As test and measurement equipment plays an indispensable role in all this, Chroma ATE will be right at home at the forefront of this market.
Visit Chroma for more information: https://www.chromaate.com/
Chroma ATE recently held a seminar on "Mastering EV/Energy Storage Testing Technology: Moving Towards Energy Sustainability," to discuss this issue from multiple perspectives, i.e. industry trends, test and measurement technology, and energy sustainability
Photo: Chroma