The Measuring Principle and Method of Telemetering Module of the Remote Terminal Unit

In electric power system, remote terminal unit (RTU) are widely used as a very important part of supervision control and data acquisition system (SCADA). One important function of RTU is telemetering. There are two methods to measure AC quantity in telemetering module of RTU: DC sampling method and AC sampling method. In this paper, the principle and method of AC sampling, the hardware and software design of RTU telemetering module are introduced, the error of AC sampling method is analyzed, and a method of reducing the error is given.