基于PLC外加计数模块的水轮机调速器频率测量

作为水轮机调节的基础，水轮机调速器频率测量中的测频准确度和精度，与水轮机的安全运行息息相关。在其频率测量方式中，基于可编程控制器（PLC）的水轮机调速器频率测量，具有易于编程、精度高以及维护方便等特点，已成为水轮机调速器测频主流，其主要形式有基于PLC的内部高速计数器和基于PLC的外加高速计数模块2种。主要介绍了运用外加施耐德BMX EHC 0200高速计数模块进行频率测量的原理；同时，也对其所具有的特点、频率计算过程与计算方式等作了简单描述。

Frequency measurement of hydro-turbine speed regulator based on external counting module of PLC

As the basis of hydro-turbine regulation, the accuracy of frequency measurement of the hydro-turbine speed regulator has a direct influence on the safe operation of the turbine. Owing to its advantages of easy operation, high accuracy, and convenient maintenance, PLC (Programmable Logic Controller) is widely used to measure the frequency of hydro-turbine speed regulator, which can be realized in two forms: internal counting module and external counting module of PLC. The principles of frequency measurement based on external Schneider BMX EHC 0200 high speed counting module is introduced. Meanwhile, its characteristics, frequency calculation process and calculation mode are described as well.