ALEXANDRIA, Va., July 3 -- United States Patent no. 12,348,043, issued on July 1, was assigned to State Grid Hebei Electric Power Co. Ltd. Research Institute (Shijiazhuang, China), State Grid Hebei Electric Power Co. Ltd. (Shijiazhuang, China) and State Grid Corporation of China (Beijing).

"Method and apparatus for allocating virtual inertia in photovoltaic cluster" was invented by Hui Fan (Hebei, China), Jifeng Liang (Hebei, China), Peng Luo (Hebei, China), Tiecheng Li (Hebei, China), Siming Zeng (Hebei, China), Qian Zang (Hebei, China) and Leibao Wang (Hebei, China).

According to the abstract* released by the U.S. Patent & Trademark Office: "The method includes: determining required virtual inertia based on a frequency change rate monit...