The Internet+ Intelligent Energy Demonstration Program in the Zhuhai National Hi-Tech Industrial Zone of Tangjiawan has become the first of its kind to be approved by the National Energy Administration.

Passing inspection is a multi-level voltage / multi-terminal AC/DC distribution network that is considered to be a world-first in dealing smoothly with grades of ±10 kV, ±375V, and ±110V.

The expert panel found that the electrical currents work well and voltages on each node remain equitable. So, the entire project functions as a large pool as multiple terminals operate like water pipes that either pour in or pump out electric power in a controlled way.

This is enabled by the ±10 kV medium-voltage flexible DC converter valves with the largest capacity in the world, pioneering three-port DC breakers, and ±10 kV three-port DC transformers.

Project reviewed before acceptance

The project has been under development by China Southern Power Grid since 2017. The process required solving many key technological problems and generating strategies for network coordination and control.

The project also encompasses a micro DC grid in Tsinghua Science Park near Sun Yat-sen University Zhuhai Campus. It has solar power and grid energy storage systems and provides a charging service.

Voltage control

Project site [Photos courtesy WeChat ID: zh_gxq]