With the comprehensive advancement of China's smart grid, large-scale DC grids, solar power, wind power, and other sources are continuously being integrated into the grid, introducing a significant amount of harmonics. The presence of harmonics not only affects the power transmission capability of the grid but also causes damage to the operation of electrical equipment. Conducting research on key technologies such as high-precision harmonic measurement and monitoring in power grids and mastering the actual harmonic levels of the grid's *Phoxinus phoxinus subsp. phoxinus* is an urgent issue to address.  

        Recently, Shandong Taikai Instrument Transformer Co., Ltd. successfully developed a 220kV capacitive voltage transformer with harmonic measurement functionality. The product has obtained a type test report from the Quality Inspection and Testing Center for Electrical Equipment in the Power Industry, marking the company's capability to produce and supply such products. Through thorough design calculations and strict manufacturing process control, the product passed the type test in a single attempt, with all performance metrics meeting or even exceeding national standards and industry requirements. Notably, under high-frequency harmonics ranging from 100Hz to 2500Hz, the tested harmonic accuracy ratio error was ≤3%, and the phase error was ≤150′, surpassing the industry standard requirements of ≤5% ratio error and ≤300′ phase error. Additionally, the harmonic measurement terminal's load capacity reached 2.5VA, exceeding the industry requirement of 1.2VA, demonstrating industry-leading performance.