Abstract: The design principles and constraint conditions to design the turbine with measurement while drilling(MWD)technique were proposed on the basis of the classical two-dimensional design theory of turbine. A mathematic model of alternator was built for analyzing the electromagnetic characteristics with vector analysis method. The internal impedance model of alternator was used to analyze the relation between the exterior voltage characteristics or voltage regulation rate and the armature reactance with numerical calculation. The research results demonstrated that the internal impedance of alternator had both current and power factor angle feedback characteristics, which improved the voltage regulation rate to a certain extent. Additionally, an optimal variation range of the armature reactance, in which there was less voltage regulation rate, was put forward. The characteristic parameters of the MWD turbine were computed and analyzed based on the experimental data of the downhole MWD turbine alternator, the theoretical analysis of the alternator electromagnetic characteristics and turbine design theory.

Key words: turbine alternator, exterior voltage characteristics, torque, armature reactance, voltage regulation rate, effective power, numerical simulation, measurement while drilling technique

摘要： 依据经典的二维涡轮设计理论,研究了井下随钻测量涡轮发电机涡轮设计过程中应遵循的原则及约束条件。根据发电机电枢的双反应原理,采用相量法建立了发电机研究模型和内阻数学模型,通过数值分析手段研究了发电机外特性和电压调整率与电枢反应电抗之间的关系。研究结果表明,发电机内阻具有的电流负反馈和功率因数角负反馈特性,在一定程度上改善了电压调整率,并确定出了获得最佳电压调整率时电枢反应电抗的变化区域。根据涡轮发电机实验测量数据,结合发电机电磁特性的理论分析以及涡轮设计理论,计算分析了涡轮的实际工作特性参数。

关键词: 涡轮发电机, 外特性, 转矩, 电枢反应电抗, 电压调整率, 有功功率, 数值模拟, 随钻测量技术