A monitoring system that provides scalability, expandability and high stability is established to monitor wind power generation, solar power generation and energy storage by adopting a battery information concentrator (VP-25W1) and a battery cabinet management platform (XP-8341) in a solution provided by ICP DAS, together with the battery management unit (BMU) developed by the customer, which operate based on the highly fault-tolerant and fault-detectable CAN Bus protocol.
As the world’s largest battery energy storage station at present, the Zhangbei National Wind and Solar Energy Storage and Transmission Demonstration Project—a project in Zhangbei, Hebei Province, China, has implemented the world’s first ever construction concept and technical route for wind and solar energy storage and transmission. The model is a new energy comprehensive demonstration project that integrates wind power, photovoltaic cells, energy storage devices and smart power transmission.
By taking the instability of wind and solar power generation and the high and low peak times for power consumption from the grid into consideration, any redundant power can be stored when the power generation capacity is greatest, or during the low peak period from 7:00 pm to 7:00 am. Any power energy previously stored in the storage station can then be fed back to the grid to supplement the gap in power demand, and solve any problems related to power demand that may arise where low power generation or peak power consumption that occur during peak usage from 9:00 am to 3:00 pm.
Even More Difficult System Maintenance Rendered by Severe Environment and Complex Communication Technology
● Severe Environment
As the daily average temperature in Hebei Province, China is less than 0°C for more than half of the year, it is particularly important for the battery management system (BMS) to be able to perform robustly, and remain stable under high temperature and low temperature conditions, no matter whether it is subjected to a temperature shock of – 30°C to 85°C, or whether it is installed at a high altitude of more than 4000 meters.
● Complex Communication Technology
The battery management unit (BMU), which was developed by the customer, monitors the charging status (SOC), the health status (SOH), the storage capacity, the battery temperature, the charging current and other information from multiple battery packs with a view of achieving the management of every single battery cabinet, the provision of data from multiple battery cabinets for subsequent power feeding and energy storage operations, and the transmission of the battery status and energy storage status from each battery pack to the remote monitoring center.
ICP DAS Solution Tailored for the Zhangbei National Wind and Solar Energy Storage and Transmission Demonstration Project (China)
Each group of systems includes a battery cabinet management platform, under which a maximum of 12 battery information concentrators can be connected. Each battery information concentrator can be connected to a maximum of 18 BMUs. The system architecture is shown below:
The BMU in the bottom layer is responsible for collecting the relevant information about the battery packs, such as the battery power, the temperature, the SOC, the SOH, the charging current, and the charging voltage, as well as providing this information to the battery information concentrators through the CAN Bus interfaces. After collecting the information from the battery packs, the battery information concentrators regularly upload the information to the XP-8341 battery management platform through the CAN Bus interfaces. Two I-8120Ws devices are used as the CAN Bus communication interface expansion system in each battery information concentrator, where one of the I-8120W modules is responsible for communication with the BMU, while the other is responsible for communication with the battery management platform, whereby, in addition to achieving isolation between the two CAN Bus interfaces, the information from the device is also separated so as to reduce the bus load from the respective CAN Bus domains.
The battery information concentrator not only collects the information from the BMU, but also constantly detects the current and voltage signals fed from the insulation detectors in the battery cabinet through the I-7012F and I-87017W modules, as well as regularly reports the data back to the battery cabinet management platform. As the maximum voltage for the battery cabinet can reach 700 VDC during the charging of the energy storage station, timely detection of the insulation status is required in order to prevent damage to the equipment or even the occurrence of work safety accidents caused by insulation failure.
The battery cabinet management platform not only manages the status of the battery pack in each battery cabinet, but also sends the relevant information to the transmitter through the RS-232 and RS-485 interfaces. In addition, the battery cabinet management platform regularly polls the insulation detectors to determine whether any alarms have been initiated, and performs the On and Off control of the battery relays. In order to prevent any danger caused by the battery relays’ being uncontrollable due to the failure of the battery cabinet management platform, the I-87068W module was especially selected as the DO module to control the battery relays, as it contains an MCU and a watchdog timer. If the battery cabinet management platform is not able to communicate with the I-87068W module for a specific period of time, the module will then output a safety value based on the preset output state configured for each DO in order to prevent any danger caused by the battery cabinet management platform being out of control.
The battery cabinet management platform includes an external Ethernet communication interface through which the information from the battery cabinets in the entire energy storage station can be transmitted to the remote monitoring center for monitoring and control.
To understand the status of each battery cabinet at the site of the energy storage station, all the relevant information from each battery cabinet is accessible either through the screen display for the battery cabinet management platform, or through the screen for the battery information concentrator embedded in the door of each battery cabinet. This can be achieved by switching the pages on the resistive touch screen to display the detailed information from all the battery packs in each battery cabinet, allowing facilitation of daily routine maintenance.
Benefits Provided to this Project by Implementing the ICP DAS Solution
- The BMS can still operate normally no matter whether it is subjected to a temperature shock of – 30°C to 85°C, or whether it is installed at a high altitude of more than 4000 meters.
- Thanks to the highly fault-tolerant and fault-detectable capability of the CAN Bus, even in a noisy electrical environment, the entire on-line system operates reliably, saving a lot of space, and ensuring that the convenience of maintenance is facilitated.
- EMI testing and high and low temperature testing services are also provided to ensure that the customers feel satisfied.
The Zhangbei National Wind and Solar Energy Storage and Transmission Demonstration Project (China) has operated in a safe and stable condition for many years since it was put into operation on December 25, 2011. Based on the statistics obtained in 2016, the cumulative output of high-quality and safe green energy has been greater than 1.65 billion kilowatt-hours. With the success of this project, it will definitely play an important role in the 2022 Winter Olympic Games to be held in Zhangjiakou in Beijing, as well as in the development of the Beijing electric vehicle industry.
“Safety and Stability” has been the core value pursed by ICP DAS, having been dedicated to the research and development of our products for many years, while “Uniqueness” has been our consistent approach to serving our customers. We have a strong R & D team and professional service personnel to provide our customers with the most adequate solutions. The Zhangbei National Wind and Solar Energy Storage and Transmission Demonstration Project (China) is one of many cases administered by ICP DAS.
ICP DAS was established in 1993 and strongly focuses on innovation and the enhancement of industrial automation technology. ICP DAS continuously endeavors to develop a comprehensive selection of products ranging from remote I/O controllers, distributed I/O modules, I/O data acquisition boards, programmable automation controllers, industrial communication modules, web-related products, motion control systems, SCADA/HMI software to automation solutions for applications critical to energy management, motion automation, smart factories, intelligent buildings, and smart cities. Our ambition is to provide a wide range of high-quality products and versatile applications, together with prompt and efficient services, that can be implemented to assist in the continued success of our clients worldwide.