Abstract: This paper introduces the testing of medium-voltage transmission systems in two parts. Each part focuses on explaining the testing items and methods, including the testing basis, requirements, and methods for medium-voltage variable frequency speed control systems. The standard testing items for converters as components and the testing methods for PDS frequency converters are described in detail, while general tests are only briefly described. It is hoped that this paper will contribute to the continuous improvement and enhancement of medium-voltage variable frequency speed control system testing in the future. Keywords : Medium-voltage variable frequency speed-regulating system, converter, PDS system test [b][align=center]Test of Medium-voltage Variable Frequency Speed-regulating System Zhang Qing Liu Zhendong Wang Jianghua Chen Xuemei[/align][/b] Abstract: The medium-voltage variable frequency speed-regulating system was introduced in two aspects. The emphasis is on explaining test items and methods in each part, especially on detailed analysis of testing items for the medium-voltage variable frequency speed-regulating system. Common tests, such as those for the PDS drive system, are also introduced. This general description is intended to be useful and helpful for improving the capability of the medium-voltage variable frequency speed-regulating system. Keywords: medium-voltage variable frequency speed-regulating system, converter, PDS system test 1 Introduction With the development of China's economy, large and medium-voltage motors are playing an increasingly important role in industrial production such as power and metallurgy. Their energy consumption accounts for a large portion of the total energy consumption. Improving the efficiency of this energy use can greatly reduce industrial energy consumption. Medium-voltage variable frequency speed control technology is an effective solution to the energy-saving problem. In recent years, with the promulgation of testing standards for medium-voltage variable frequency speed control systems, we have conducted extensive testing work. The testing process for medium-voltage variable frequency speed control systems is described below. [b][align=center]For details, please click: Medium-voltage Variable Frequency Speed ​​Control System Testing[/align][/b]