基于EPON通信的智能配电网馈线差动保护

Feeder Differential Protection Based on EPON Communication for Smart Distribution Networks

智能配电网正朝着网格化、多电源的拓扑结构发展,传统配电网保护、馈线自动化(FA)已经越来越难以满足智能配电网自愈的要求。电流差动保护由于其优越的速动性、灵敏性和选择性而广泛地应用于输电线路,现有的方法是采用专用光纤通道或者基于同步数字系列/准同步数字系列(SDH/PDH)技术的复用通道来实现,但架设这些通信设备费用高且通信速率慢。文中提出并研制了一种适用于智能配电网的差动保护的装置,该装置基于以太无源光网络(EPON)来实现差动保护装置之间采样数据的传输,配以抗延时抖动及IEEE 1588同步算法,实现多端线路差动保护。测试表明,保护能够准确动作,满足精度和动作时间的要求。该装置已在某10 kV线路挂网运行。

The development of smart distribution grid is towards the meshed and multi-source network topology,and the traditional feeder protection and automation（ FA） are finding it increasingly difficult to meet the requirements for self-healing. Current differential protection is widely applied to the protection of transmission feeders owing to its inherent strengths of high sensitivity,selectivity and speed,which relies on the provision of a relatively high-bandwidth communication channel,and the existing synchronous digital hierarchy / plesiochronous digital hierarchy（ SDH / PDH） networks have proven well suited to this task,but the communication equipment has a low bandwidth and is costly for the distribution grid. This paper presents a current differential protection device for the smart distribution grid,and the sampling value（ SV） can be exchanged between these devices over the Ethernet passive optical network（ EPON）. The device adopts the SV synchronization algorithm based on IEEE 1588 to realize current differential protection of multi- terminal distribution lines. Now the device has successfully been put into operation in some 10 kV distribution lines.