This project is a major equipment research and development project of the national energy system and belongs to the field of electromechanical equipment. Innovatively established a domestic 20MW class direct-frequency explosion-proof synchronous motor with a rated speed of 4800r/min and a speed regulation range of 3,120 - 5,040 r/min, and pioneered the industrial application test evaluation of a variable-frequency speed-regulating synchronous motor., established research and development technical conditions and complete sets of plans, and the project equipment is used in the national West-East Gas Pipeline Project. It solves the potential risk control problem caused by the direct application of the first motor in actual natural gas pipeline production systems. The technical conditions for localized trial production of a 20MW high-speed direct-connected variable-frequency speed-regulating synchronous motor were developed for the first time, forming a technical system for motor development. Comprehensive analysis of the technical characteristics of international mainstream electric drive units, aiming at the construction needs of contemporary large and medium-sized natural gas pipelines, through integrated innovation, it is determined to develop ultra-high-speed synchronous motors that can be directly connected to mainstream compressors, so that electric drive units of the same power level can be rid of the huge, complex gearbox structure simplifies the unit shafting, reduces maintenance costs, and improves operating efficiency. Different from the traditional and foreign common stand-alone factory test mode for each single equipment, we have independently developed PDS factory joint debugging test technology, complete machine factory online on-load test technology and industrial application test technology, and established a domestically produced 20MW electric drive unit for the first time in China. Pre-industrial application test system. The developed 20 MW-class 4800r/min large-capacity variable frequency speed drive system is the first in China. Its direct application in backbone natural gas transmission pipelines related to the national economy and people's livelihood has certain potential risks. Therefore, it is necessary to establish corresponding test and evaluation technology before the industrial application of the domestic 20 MW-class electric drive unit. The PDS factory joint debugging test includes 2 major and 14 sub-items tests to verify the availability of PDS and the reliability of the control system; the complete machine factory online on-load comprehensive test includes 4 major and 73 sub-items tests to verify the consistency of the corresponding technical indicators and requirements determined by the design, manufacturing, and final assembly quality and technical conditions of the complete machine; the complete machine industrial application test technology includes 11 major test items to verify the safety, usability and reliability of the complete machine in the industrial application. The three-stage test is supported in sequence and controlled stage by stage to ensure the safety and reliability of the whole machine. Due to the high compressor speed and explosive gas environment in the large-scale natural gas transmission pipeline of the West-East Gas Pipeline, the requirements for the driving motor are very stringent (the motor is required to reach 20MW, the speed range is adjustable from 3120 to 5040 r/min, frequency conversion operation, and positive pressure explosion proof). According to the traditional domestic technology at that time, large-capacity 4-pole synchronous motors were generally used, with a maximum speed of only 1500r/min. A speed-increasing gearbox was needed to drive the compressor. This method not only had a large investment in equipment, but also had a large amount of maintenance work. The operating efficiency of the unit was also very low. The main technical innovations during the development of this motor are: 1) The first brushless excitation system, and the domestic synchronous motor realizes the slip ring free frequency conversion synchronous starting and operation of the motor for the first time;2) The unique structural design of the motor meets the requirements of solid rotor synchronous motor inverter power supply and high-frequency operation;3) The innovative wind path design of the motor allows the main motor and excitation system to be well cooled, with low motor noise and low wind friction loss; 4) The three-bearing rotor design meets the requirements of wide speed regulation range and ultra-high speed operation;5) The positive pressure ventilation explosion-proof design of a large-capacity, three-bearing, and dual-base motor; two invention patents and six utility models were produced during the development of the motor. patent. After the successful development of the first set of motors, all compressor driving motors in domestic natural gas transmission pipelines have adopted domestically produced ultra-high-speed explosion-proof frequency conversion synchronous motors. So far, 7 motors have been delivered and 15 motors have been ordered. The output value was 130.07 million yuan, the profit was 37.2 million yuan, and the new tax revenue was 18.01 million yuan. The development of a 20 MW-class ultra-high-speed explosion-proof variable frequency synchronous motor can meet the annual throughput of 15 billion cubic meters and 30 billion cubic meters of long-distance transmission pipelines, meet the needs of flexible power adjustment in stations and yards, and has a broad market promotion scope.