基于环轭探测线圈的双余度永磁辅助同步磁阻起发电机匝间短路故障诊断OA

A dual-redundancy permanent magnet assisted synchronous reluctance machine(PMA-SynRM)integrates the redundancy concept with multi-phase winding technology.By enhancing the reluctance torque proportion and reducing permanent magnet flux linkage,PMA-SynRMs significantly improve fault-tolerant capability,making them suitable for aerospace starter-generator applications.To further enhance reliability in aerospace applications,this paper proposes an interturn short-circuit fault(ISCF)diagnosis method based on a yoke search coil(SC).Wound on the stator yoke,these SCs effectively mitigate interference from tooth saturation and end-winding leakage,improve diagnostic reliability,reduce the number of required SCs,and enhance flexibility in coil configuration.In addition,the proposed method can identify the redundancy associated with the fault source.It amplifies the detection signal,increasing sensitivity and improving the speed and accuracy of diagnosing ISCF. This paper studies the ISCF model of the PMA-SynRM,analyzes three major design rules and methods of yoke SCs,and establishes a simulation model.The proposed diagnosis method is verified under various fault conditions and the influence of non-ideal factors.Yoke SCs are designed following three key rules.(1)The SCs must detect faults at all positions while minimizing the number of SCs.(2)The SCs should output zero voltage under normal operation.(3)The search coil group(SCG)corresponding to the faulty redundancy should output a larger voltage signal than that of the healthy redundancy.Using a 48-slot 8-pole PMA-SynRM,these rules guide the design of coil structure,placement,series connection,and grouping.Compared with traditional tooth-mounted SCs,the proposed yoke SCs reduce interference from tooth saturation and leakage flux,enhancing diagnostic reliability for aerospace applications. The fault diagnosis process is as follows.When an ISCF occurs,the yoke SCGs detect voltage signals at frequencies of 1fe and 3fe.The sum of these components is defined as the fault characteristic parameter xr.To detect the most challenging single-turn short-circuit fault(STSCF),the threshold xval is set based on xr value generated by the rated current during STSCF.The ratio between the threshold xval and rotor speed nr is 23.3 mV/kr/min.Simulation results show that for STSCF in different coils of Redundancy-1,an alternative signal is generated in SCG-1,while SCG-2 remains zero.The fault signature in SCG-1 is significantly larger than xval,enabling STSCF detection and localization.Non-ideal factors,such as eccentricity and current asymmetry,induce voltages below xval,preventing false alarms. A prototype and a test bed were constructed.Experimental results align with simulations.(1)As contact resistance rsc decreases from 100 mΩ to 10 mΩ,the measured xr in SCG-1 increases from 0.21 V to 1.18 V,both exceeding the 6 000 r/min STSCF threshold xval=0.14 V.(2)For ISCFs in different coils of Redundancy-1,the short-circuit loop current remains nearly constant.However,the xr reaches the highest 0.98 V when the fault is in coil T3(closest to SCs)and minimizes at 0.37 V for a fault in coil T1.Both values exceed 0.14 V.(3)As load increases from 0 N·m to 8 N·m,the xr of SCG-1 increases from 0.38 V to 0.47 V,remaining above 0.14 V.The experimental results show that the proposed yoke SC provides a practical solution for high-reliability ISCF diagnosis in aerospace applications.