Recently, two local standards in Shandong Province, "Technical Specification for Condition Maintenance of Natural Ester Insulated Oil Transformers" and "Technical Specification for Handover Test of Natural Ester Insulated Oil Transformers", led by State Grid Shandong Electric Power Research Institute, were officially approved and released by the Shandong Provincial Administration for Market Regulation. They are the first batch of local standards in Shandong Province to standardize the requirements for handover test and condition maintenance of natural ester insulated oil transformers.

Compared to traditional mineral insulation oil, natural ester insulation oil is a green and environmentally friendly insulation material that can automatically degrade, is safe and harmless, and has zero carbon emissions. It is more in line with the national "dual carbon" requirements. In 2018, Shandong Province has installed natural ester insulation oil transformers with several voltage levels including 10 kV, 35 kV, and 110 kV. Unlike mineral oil transformers, the handover test of natural ester insulated oil transformers has its own characteristics, but there is still no unified standard for the handover test and condition maintenance before its current operation. The technical personnel of the power transmission and transformation center of the institute, in collaboration with 19 natural ester insulated oil transformer related production enterprises, universities, and user units such as Shandong Electric Power Equipment Co., Ltd. and Shandong Product Quality Inspection and Research Institute, completed the project proposal, drafting, soliciting opinions, expert review, and standard approval based on extensive research on standard policies, on-site requirements, and technical issues. Finally, the project was officially approved and released by the Shandong Provincial Administration for Market Regulation.

The "Technical Specification for Condition Maintenance of Natural Ester Insulated Oil Transformers" fully combines the development and application status of natural ester insulated oil transformers in Shandong Province, stipulates the implementation principles of condition maintenance, the work content of condition evaluation, clarifies the calculation methods of routine test cycles for newly put into operation equipment maintenance, old equipment maintenance, power outage, and the maintenance content of shutdown equipment. It has a guiding role in promoting the standardization of condition maintenance of natural ester insulated oil transformers, and has important practical significance in ensuring the timely elimination of latent faults and safe operation of natural ester transformers after they are connected to the network. The Technical Specification for Handover Test of Natural Ester Insulated Oil Transformers specifies 21 handover acceptance test items, technical requirements, and judgment criteria for natural ester insulated oil transformers after on-site installation and before operation. It has a guiding role in promoting the standardization of handover test of natural ester insulated oil transformers, effectively discovering quality problems of natural ester insulated oil transformers, facilitating equipment handover and acceptance by equipment user units, and is of great significance for ensuring the smooth network connection and safe operation of natural ester transformers.

Next, technical personnel from State Grid Shandong Electric Power Research Institute will continue to promote the revision of technical standards for natural ester insulated oil transformers, actively promote the application of green and low-carbon new materials such as natural ester insulated oil in the power grid of Shandong Province, and contribute to the construction of a clean, low-carbon, safe and efficient modern energy system in Shandong Province.