特高压直流系统中大容量双水内冷调相机的作用及关键技术研究

大容量双水内冷调相机在特高压直流系统中具有快速响应的无功补偿支撑作用。为了满足大容量双水内冷调相机动态无功调节、快速响应和安全可靠性能要求,通过优化电磁设计,提高了调相机的暂态和次暂态特性、强励能力和出力范围。探讨了通风冷却系统设计和调相机定、转子温升计算。在绝缘设计方面,采用内屏蔽结构,通过半导体材料实现了均压层的屏蔽作用,增大换位填充倒角半径,提高了定子线棒角部电场的均匀性,采用一次成型的定子线棒防晕结构,优化了调相机的主要电气性能指标。在结构设计方面,定子绕组采用了端部整体灌胶结构,有效地防止了端部松动问题。定子铁芯使用全补偿、抗蠕变防松技术以防止铁芯因基频和倍频振动导致的松动。研究结果表明,大容量双水内冷调相机特殊的冷却方式、电磁、绝缘和结构工艺优化设计等关键技术,可以使得大容量双水调相机满足特高压直流系统无功支撑。

Research on the Function and Key Technology of the Large-capacity Dual Internal Water Cooled Synchronous Condenser in UHVDC System

Large-capacity dual-water internal cooling condenser has the function of reactive power compensation support with fast response in UHVDC system.In order to meet the performance requirements of dynamic reactive power regulation,fast response and safety,and reliability,we designed a large-capacity dual-water internal cooled camera to improve the transient and sub-transient characteristics,excitation power and output range of the camera.Moreover,we discussed the design of ventilation cooling system and the calculation of temperature rise of stator and rotor.In the aspect of insulation design,the inner shield structure is adopted,the shielding effect of the equalizing layer is realized through semiconductor materials,the chamfer radius of the transposition filling is increased,the electric field uniformity of the stator bar corner is increased,and the electrical performance index of the main regulator is optimized by adopting a once-through forming stator bar anti halo structure.In the aspect of structural design,the overall glue filling structure at the end is adopted for the stator winding,which effectively prevents the end from loosening.A full-compensation and creep-resistance technology to prevent loosening of the core is adopted for the stator core due to fundamental frequency and frequency doubling vibration.The research results show that the key technologies such as the special cooling mode,electromagnetic,insulation and structural process optimization of large-capacity dual-water internal cooled camera can make it to satisfy the reactive power support of UHVDC system.