Design of wireless power transmission coupling structure based on rotary steerable drilling

In this paper, a DD-4D double-layer orthogonal magnetic coupler with mutual inductance compensation is proposed for powering electrical equipment mounted on fixed sleeve during rotary steerable drilling. It can not only transfer the electric energy from the rotating side to the stationary side, but also ensure the stability of the transmission efficiency of the wireless power transmission system. Firstly, the topology and working principle of DD-4D double-layer orthogonal coils are proposed and the typical WPT system of rotary steerable drilling is analyzed. Secondly, the influence of the center angle and the number of combinations of DD transmitting coils with good lateral anti-migration performance on mutual inductance of the magnetic coupler was investigated. Thirdly, the DD-4D double-layer orthogonal coils' model is determined to solve the problem of mutual inductance zero coupling point during rotation. Fourthly, the simulation characteristics of lateral migration axial migration and off-axis angular migration are studied respectively. Fifthly, an experimental model is established to verify that the comprehensive efficiency of the system is 88.56% and the efficiency offset rate is only 3.34%.