uSED FOR PC display, record and so on. The cooling condition of the INVERTER is greatly improved. All the components of the inverter can be installed in the periphery of the shell of the mine, which saves the radiator with large volume. When running into water, these devices will be water-cooled, the power load capacity of the device has been greatly improved. Therefore, with the same output power, the volume and weight of the converter can be made much smaller than the ordinary converter. As a mature technology, variable frequency speed regulation has been widely used in various industrial fields. Many domestic units are engaged in the research and production of frequency converters and related power devices. Technically speaking, it is feasible to study suitable frequency conversion speed governor. The frequency converter can be studied from the following aspects: the Study of special devices, the solution of the installation mode of power devices with specific shape required for the installation of Rene, the study of the working mechanism, the solution of the problem of matching the parameters with the motor, ensure that the motor system has the required speed range and output power. The Cooperative Action Mechanism is studied to solve the problem of cooperative action with related systems, and to ensure the motor system to operate according to the predetermined procedure and speed. In a word, the power system of variable-frequency and adjustable-speed asynchronous motor is feasible in design and manufacture, and has superior technical performance because of its low cost, convenient maintenance and use, will produce higher benefit and economic benefit.