ABB控制局部放电高压电动机和发电机白皮书.pdf

— WHITE PAPER Controlling partial discharge in high voltage motors and generators 2 A PPLI C ATI O N G U I D E ACH 5 8 0 A LTER N ATI V E M OTO R TECH N O LO G I E S I N H VAC 3 — Table of contents 004 Introduction – what causes partial discharge? 005 Key roles for design, materials and workmanship 006 Detecting and measuring PD 008 Condition monitoring and service 009 Does it make sense to stipulate low PD levels? 010 Conclusion 011 Notes 44 CO NTRO LLI N G PA R TI A L D I S CH A RG E H I G H VO LTAG E M OTO R S A N D G EN ER ATO R S — Introduction – what causes partial discharge? Partial discharge (PD) occurs in high voltage (HV) exceeds the threshold to ionize the air. Factors electrical equipment like cables, transformers, behind external PD can include poor air motors and generators. It is a kind of very small clearances, contamination on the end-windings, spark that occurs due to a high electrical field. In and variations or defects in the corona protection industrial high voltage motors and generators, in the slots or on the end-windings. External PD is electrical stress can reach several kilovolts per generally easy to detect by visual inspection as it millimeter and this can give rise to PD either usually results in a deposit of white powder on inside the insulation (internal PD) or on the the surface of t