Since the establishment of the People’s Republic of China, the country has made significant progress in tunnel construction, transforming from a “weak tunnel nation” to a “strong tunnel nation.” As of 2022, China has undertaken more than 60 projects involving large-diameter shield tunnels. To promote the sustainable and high-quality development of large-diameter shield tunnels in China, this article systematically reviews the development history of large-diameter shield tunnels, summarizes the current projects in the country, and addresses various aspects such as construction technology management, design technology, ecological conservation, safety, and intelligence. The article also provides suggestions for the development of large-diameter shield tunnels in China, with the aim of playing a proactive role in promoting their advancement.

Both a classical instantaneous power method and a method based on equations of instantaneous power orthogonal components balance have been used to analyze power processes in electric circuits with semiconductor elements. Automated method of forming instantaneous power harmonic components was used to obtain analytical expressions and numerical values of instantaneous power components of analyzed electric circuits. A coefficient for estimation of a semiconductor converter nonlinearity degree has been offered.