Study On The Effect Of Rotation And Strong Coupling On Contactless Sliprings

Aiming to avoid the inherent friction and the associated low reliability for mechanical sliprings,contactless sliprings(CS)based on inductive power transmission(IPT)are studied in the paper.The performance of CS is different from that of the static or sliding IPT system due to the rotation and the millimeter-level gap.Hence,the effect of rotation and strong coupling on CS are investigated.Moreover,the solutions are presented based on the analysis.Firstly,the steady state mathematical model for three-phase CS is built,and then electrical properties of the three-phase CS are investigated considering rotation of CS.Additionally,the quantitative analysis of resulting torque by rotation are performed through power flow analysis.Both dynamic tuning and field-unoriented control solutions are proposed to eliminate the side effects due to rotation.The effect of strong coupling on the performance of CS are studied by impedance analysis,pointing out that the strong coupling will lead to the increase of harmonic.Then the double-channel CS system is proposed to make use of the fundamental and harmonic energy at the same time.For the proposed CS system,the decoupling and independent power control of the two channels can be achieved.Besides,through parameter optimization,the higher efficiency and power transfer capability can be realized.Finally,the validity of the theoretical analysis is verified by the experiments.The accuracy of the modeling is verified by a three-phase CS prototype.The effect of the strong coupling is verified by a single-phase face to face CS.The decoupling performance and power transfer capability are verified by a double-channel CS system.At last,a 5kW single-phase coaxial CS with a highest efficiency of 97.46% is fabricated,along with the loss analysis with the aid of a double pulse platform.