On September 27, the COM7010 flexible DC valve DC link capacitor monitoring device developed by LandPower, a subsidiary of SUN.KING Technology Group, was successfully put into trial operation on the Zhangbei Flexible DC Project, the world's first flexible DC power grid project, helping the localization of high-voltage and large-capacity dry-type DC capacitor, the core components (materials) of flexible DC transmission, and contributing to solving the key "bottleneck" problems that restrict the research and development and manufacturing of major UHV equipment in my country.

With the "dual carbon" goal proposed, accelerating the construction of a new energy system and building a new power system has become a broad consensus. Flexible DC transmission is a new generation of advanced DC transmission technology, which has outstanding advantages such as no commutation failure, continuous power regulation, voltage and frequency support for the power grid, few output harmonics, and black start capability. Flexible DC transmission technology is a key technology for building a new power system. It has urgent application needs in supporting large-scale new energy transmission under weak AC power grid at the sending end, improving the safety and stability level of multiple DC centralized feed-in to the receiving end power grid, and realizing asynchronous interconnection of large regional power grids.

As the energy storage element on the DC side of the voltage source converter in the flexible DC transmission system, the DC link capacitor can provide a smooth DC voltage for the converter. At the same time, it can buffer the DC side voltage fluctuation caused by system failure, reduce the DC side voltage ripple, and prevent the DC overvoltage overshoot of the IGBT. For a long time, my country's flexible DC dry capacitor have been completely dependent on imports, resulting in increased construction costs for flexible DC projects, key technologies and core components being controlled by others, and seriously threatening my country's power grid development and energy security. With the improvement of my country's equipment manufacturing process, domestically produced flexible DC dry capacitor have been developed.

Zhangbei Flexible DC Grid Demonstration Project Flexible DC Transmission Equipment

High voltage and high current impact operating conditions will accelerate the aging of capacitor and eventually lead to capacitor failure, which will directly affect the operation safety of high-voltage DC transmission systems. Langde has developed the COM7010 flexible DC converter valve DC link capacitor online monitoring device, which realizes real-time intelligent analysis of capacitor operation status and provides status data support for the safe and reliable operation of domestic DC link capacitor for flexible DC valves.

The COM7010 device uses self-powered power supply and intelligent wireless communication technology, which is easy to install and maintain, safe and reliable; it uses high-precision sensor modules and anti-interference technology to ensure measurement accuracy and operational stability.

"Zhangbei's wind lights up Beijing's lights" has become a good story. Based on the reverse distribution characteristics of my country's energy resources and demand, considering the randomness and strong spatiotemporal correlation of new energy output, it is still necessary to expand the scale of flexible DC transmission network to meet the needs of long-distance large-capacity transmission and cross-provincial and cross-regional consumption of new energy. Langde Electric will adhere to the concept of protecting the security of the power grid by sampling numerical means, and continue to contribute to the construction of new power systems.