智能变电站是未来变电站建设的发展方向,它具有设备信息数字化、功能集成化、结构紧凑化、检修状态化等诸多优势。然而由于其采用以GIS设备为主架构的紧凑型布局,一二次设备集成安装,也带了传统变电站不具备的复杂电磁兼容问题,隔离开...智能变电站是未来变电站建设的发展方向,它具有设备信息数字化、功能集成化、结构紧凑化、检修状态化等诸多优势。然而由于其采用以GIS设备为主架构的紧凑型布局,一二次设备集成安装,也带了传统变电站不具备的复杂电磁兼容问题,隔离开关和断路器倒闸操作时产生的快速暂态过电压(Very Fast Transient 0vervotage,VFTO)将严重影响远端采集模块、合并单元的数据正确性,从而可能造成继电保护的误动作。针对某220 k V智能变电站中发生的一起因断路器电气操作产生高频瞬时电磁干扰导致无故障情况下站内母差保护误动作的现场实例,展开了系统性分析,深入探讨智能变电站中远端模块数据采集环节受到干扰的原因,并在现场开展了电气操作试验,观察隔离开关及断路器倒闸操作时产生的VFTO对远端模块的干扰情况,验证分析结果。提出并实施了合理的解决措施,保证智能变电站中继保设备的正确运行。展开更多
Quasi Z-source converter is a single stage soft switched power converter derived from Z-source converter topology, employing an impedance network coupling the source with the converter. The quasi Z-source source conve...Quasi Z-source converter is a single stage soft switched power converter derived from Z-source converter topology, employing an impedance network coupling the source with the converter. The quasi Z-source source converter can buck or boost the voltage and current flow is bidirectional. The duty cycle of the switch can be adjusted to maintain constant voltage during load change. To obtain constant output voltage, proper controller design is a must. This paper presents closed loop control of quasi Z-source converter using PI controller where controller parameters are estimated using the small signal model of the entire system. The transfer function of the system with AC sweep is used to obtain appropriate proportional and integral gain constants to reduce transient dynamics and to reduce steady state error.展开更多
文摘智能变电站是未来变电站建设的发展方向,它具有设备信息数字化、功能集成化、结构紧凑化、检修状态化等诸多优势。然而由于其采用以GIS设备为主架构的紧凑型布局,一二次设备集成安装,也带了传统变电站不具备的复杂电磁兼容问题,隔离开关和断路器倒闸操作时产生的快速暂态过电压(Very Fast Transient 0vervotage,VFTO)将严重影响远端采集模块、合并单元的数据正确性,从而可能造成继电保护的误动作。针对某220 k V智能变电站中发生的一起因断路器电气操作产生高频瞬时电磁干扰导致无故障情况下站内母差保护误动作的现场实例,展开了系统性分析,深入探讨智能变电站中远端模块数据采集环节受到干扰的原因,并在现场开展了电气操作试验,观察隔离开关及断路器倒闸操作时产生的VFTO对远端模块的干扰情况,验证分析结果。提出并实施了合理的解决措施,保证智能变电站中继保设备的正确运行。
文摘Quasi Z-source converter is a single stage soft switched power converter derived from Z-source converter topology, employing an impedance network coupling the source with the converter. The quasi Z-source source converter can buck or boost the voltage and current flow is bidirectional. The duty cycle of the switch can be adjusted to maintain constant voltage during load change. To obtain constant output voltage, proper controller design is a must. This paper presents closed loop control of quasi Z-source converter using PI controller where controller parameters are estimated using the small signal model of the entire system. The transfer function of the system with AC sweep is used to obtain appropriate proportional and integral gain constants to reduce transient dynamics and to reduce steady state error.
