导向钻井工具中电能传输用旋转式变压器设计

在导向钻井过程中,为保证导向钻井工具中旋转的主轴与不旋转套之间电能传输稳定,根据导向钻井工具的机械结构和空间要求设计了旋转式可分离变压器。通过理论分析,选择铁合金材料作为磁芯材料;根据ANSYS仿真,确定变压器初级和次级绕组之间的间隙为1 mm,旋转变压器的最佳工作频率为38 kHz;通过分析,选择初级串联次级并联型补偿电路,并根据变压器的互感模型计算了补偿电路的电容。不同输入功率下旋转变压器传输效率的的室内测试结果表明,最佳输入功率约为150 W,此时变压器的动静态传输效率都不低于82%,而当输入功率大于200 W小于300 W时,传输效率不足80%。这表明,所设计的旋转变压器可以应用到旋转导向钻井系统中,但该变压器在输入功率高时传输效率较低,达不到80%的工程要求,还需进行改进。 

The Design of the Rotary Transformer for Power Transmission in Steering Drilling Tool

To ensure the stability of electric power transmission between rotating spindle and non-rotating sleeve in steering drilling, a rotary separable transformer was designed according to the mechanical structure and space requirements of relevant steering tools.Iron alloy was chosen as the magnetic core material through theoretical analysis, and the clearance between primary winding and secondary winding was determined to be 1 mm and the optimum working frequency of the transformer to be 38 kHz, based on ANSYS simulation.Moreover, the primary series+secondary parallel compensation circuit was adopted, and its capacitance with the mutual inductance model of the transformer was calculated.Finally, the transmission efficiency of the transformer in laboratory under different input power was tested.The results showed that the optimum input power was about 150 W, under which both dynamic and static transmission efficiencies of the transformer were not less than 82%.When the input power was greater than 200 W and less than 300 W, the transmission efficiency was less than 80%.This suggested that the rotary transformer could be applied to the rotary steering drilling system, but it should be improved since its transmission efficiency was low (less than 80%) under high input power.