SF6密度继电器RS-485通信终端电阻匹配方法研究

Research on the Resistance Matching Method for RS- 485 Communication Terminal of SF6 Density Relay

SF6密度继电器能够实现对高压电器设备中SF6绝缘气体状态的实时在线监测,然而在工程实践中采常采用的RS-485组网方式存在着反射信号干扰的问题,需要在通信网络的末端SF6密度继电器中进行阻抗匹配,提出了一种软硬件结合的方法对终端电阻匹配进行控制,设计了电阻投切控制电路,并设计了相应的软件控制远传密度继电器内部终端电阻的投切,可以方便地实现RS-485通信网络的终端阻抗匹配,通过对信号波形进行分析,可以证明能够有效降地低信号反射所带来的不良影响。

While SF6 density relay can realize real-time online monitoring of SF6 insulation gas status in the high-voltage electrical equipment, the RS- 485 networking method commonly adopted in the engineering has the problem of interference of reflected signal, which necessitates impedance matching in the SF6 density relay at the end of the communication network. This paper presents a method of combination of software and hardware to control the terminal resistance matching. It designs a resistor switching control circuit, as well as corresponding software to control lhe switching of the internal terminal resistor within the density relay, so that terminal impedance matching can be easily realized for the RS - 485 communication network, analysis of the signal waves shows that this method can effectively reduce the adverse effects caused by signal reflection.