永磁同步风力发电机匝间和退磁故障早期检测

EARLY DETECTION OF INTER-TURN AND DEMAGNETIZATION FAULTS OF PERMANENT MAGNET SYNCHRONOUS WIND GENERATOR

永磁同步发电机在发电效率、可靠性、电网友好性等方面具有独特的优势,已逐渐成为5 MW及以上容量的风电机组的主流选择。该文针对永磁同步电机退磁和绕组匝间短路2种常见故障的特点和监测方法进行研究,并建立2种故障的数学模型。提出一种基于零序电压分量和故障指示量的方法,可实现匝间短路早期轻微故障检测及故障相的判断;提出一种基于滑模观测器的退磁故障在线监测方法,该方法可准确辨识永磁体磁链,具有辨识精度高和速度快的特点。仿真结果验证了2种故障诊断方法的有效性及优势。

Permanent magnet synchronous generator has unique advantages in power generation efficiency,reliability,grid friendliness and other aspects,and has gradually become the mainstream choice of wind turbines with capacity of 5 MW and above. In this paper,the characteristics and monitoring methods of demagnetization and short circuit between winding turns of permanent magnet synchronous motor are studied,and the mathematical models of these two faults are established. A method based on zero-sequence voltage component and fault indication is proposed to detect early minor fault and judge fault phase of inter-turn short-circuit. An on-line demagnetization fault monitoring method based on sliding mode observer is proposed. The method not only can precisely identify the permanent magnet flux,but also possesses the advantages of higher identification precision and faster speed. The simulation results verify the availability and advantages of the two fault diagnosis methods.