Studying On The Power System Of The Top Drive Drilling System

Top drive drilling system (abbreviated to TDS) is developing rapidly since it is born in 1980s, and it has gotten to use widely in oil drilling, especially in deep well, bad hole and marine drilling. It is the frontier tech and equipments of the drilling at present, and it has been a normal production in well drilling. It stands the highest level of well drilling technology and dedicated oil equipments that is integrated with machinery, electric and hydraulic system, and the developing trend about drilling equipments in 21 century. The development of the TDS appears multi-trend abroad these years, for instance, developing from the fixed structure to the detachable one, getting smaller and smaller in volume, designing back torque beam on the derrick, being apt to the electric motor of the AC frequency conversion in the driving way. At present, the technology in our country about the TDS is still more backward than other countries, such as the motor of the TDS still depending on importation, a large volume and a big mass about the TDS, a lower power factor about the motor in low speed, and so on. Therefore, it is important that study the power system of the TDS in order to improve the performance and the efficiency of the drilling equipment.The switched reluctance drive (abbreviated to SRD) gets better and better in performance, and the SRD has a perfect performance in variable speed control, for example, a small starting current, a big starting torque, a strong overload ability in low speed, etc. So it will get a strong developing potentiality if the SRD is used to the main motor of the TDS. In order to improve the efficiency of the TDS actuating system, the radial gear transmission with three-shaft inner planet gear is used to the power driven system of TDS, and it has some virtues, such as few component parts, small volume, simply structure, high efficiency, strong acceptance of load. This fits the requirement of the development about the TDS.In the text, the load characteristic of the TDS was analyzed, and a reducer by three-axes inner planet gear was designed. The important structural members of the reducer has been analyzed in force, and the efficiency about the gear transmission has been analyzed too. The overall structure and the cooling system about the TDS motor have been designed by the four-phase SRD with 8/6 poles, and the Motorola-DSP56F805-centric control system has been devised by the direct torque control theory, and an experiment have been run in the lab. The test effect appears that the reducer about the three-axes inner planet gear works well, runs smoothly, shakes small in full speed, the main shaft runs perfect. The SRM has a good following performance, a favorable noise immunity. And it can be controlled flexibly. This can meet the requirement of drilling in TDS.