基于编码波形的数字化变电站信号绝对传输延时测试方法

A Test Method of Signal Absolute Transmission Delay for Digital Substation Based on Coding Waveforms

数字化变电站引入的电子式互感器、合并单元、交换机等数字信号处理设备不可避免会产生一定的信号传输延时,该延时甚至可能达到数个工频周期以上,进而引发继电保护等装置误动。目前基于稳态波形的延时测试方法和设备,无法反映相差大于工频周期的延时(整周期延时)。从原理上分析了数字化变电站信号传输延时产生的机理,并介绍了现有检测方法,提出基于编码测试波形、可检测整周期延时且无需接入脉冲同步信号的智能变电站信号绝对传输延时检测方法,并研制了相应设备,验证了该方法的有效性。

The electronic transformer,merging unit,switches and other digital processing equipment introduced by digital substation will inevitably generate definite signal transmission delay.The delay may even reach several power frequency cycles, causing relay protection device maloperation.Currently,it is impossible for testing methods and equipment of time delay based on the steady-state waveform to reflect a delay with a difference greater than a power frequency cycle（whole cycle time delay）. The mechanism of signal transmission delay in a digital substation is analyzed in principle and the current detection method is summarized.A test method of signal absolute transmission delay for digital substation is proposed based on coding test waveforms,the detectable whole cycle time delay and freedom from pulse synchronizing signals.Accordingly equipment is developed and the effectiveness of the proposed method is verified.