基于正交实验的井下直线发电机设计与分析

Design and Optimization Analysis of Downhole Linear Generator Based on Orthogonal Test

针对现有井下电能供应方式发电功率低的缺点,结合直线发电的优点,提出了一种新型圆筒型井下直线感应发电方案,该发电机利用抽油杆和油管之间相对运动的方式,产生感应电流。首先,根据现有电机学原理,完成对圆筒型永磁直线发电机的结构设计,然后,利用Ansoft Maxwell对圆筒型永磁直线发电机的空载磁通量密度、空载感应电动势、阻性负载以及实际密封不严情况下的发电性能进行分析,验证了发电机设计的正确性;最后,利用正交实验的优化方法,以畸变率和发电量为优化目标,对关键结构参数进行了优化。结果表明,该发电机谐波畸变率低、发电功率大,不论在空载时还是负载时都有很好的稳定性,能够有效解决现有井下发电机发电效率低、性能不稳定的问题。

Aiming at the disadvantage of low power generation in the existing downhole power supply mode and combining the advantages of linear power generation,a new cylindrical downhole linear induction power generation scheme is proposed,which generates induced current by the relative motion between the sucker rod and the oil pipe.According to the principle of existing electrical machinery,we complete the structural design of the cylinder type permanent magnet linear generator;then we use Ansoft Maxwell to analyze the no-load flux density,no-load induced electromotive force,resistive load and the power generation performance of the cylindrical permanent magnet generator under the condition of actual sealing,and verify the validity of the generator design.Finally,the key structural parameters are optimized by using the orthogonal experimental optimization method,taking distortion rate and power generation as the optimization objectives.The results show that the generator has low harmonic distortion rate,high power and good stability no matter under load or no load.It can effectively solve the problems of low efficiency and unstable performance of existing downhole generators.