Investigation on the application of permanent magnet synchronous motor in geological drilling rig

Abstract

At present, the majority of deep borehole drilling rigs at home and abroad still utilize Asynchronous Motors (AM) with variable-frequency drive as the main power component, which cannot achieve stepless-speed adjustment without decelerating mechanism. In addition, the expenditure of lubrication and maintenance are usually high, and the transmission efficiency is not very ideal. Therefore, this paper proposes a permanent magnet electric direct-drive deep borehole drilling rig (DBZJ40-Z), which firstly adopts Permanent Magnet Synchronous Motor (PMSM) with variable frequency technique to achieve stepless-speed control and direct-drive method to remove the transmission mechanism. Owing to the higher power factor and efficiency of PMSMs, this new type of drilling rig proposed is more energy efficient than the conventional ones equipped with AMs. Furthermore, the utilization of direct-drive mechanism replaces the intermediate transmission gearbox to save a lot of cost of maintenance greatly. Advantages of this new deep borehole drilling rig equipped with PMSMs such as saving energy, easy to maintain and operate, etc. had been verified in several practical applications. Practices proved that this sort of permanent magnet electric direct-drive deep borehole drilling rig equipped with PMSMs must be the future for conventional ones.