内置RTC作为电能表计时钟的应用

为降低电能表的成本,提高时钟的精确度,设计了一个基于ST微控制器的RTC时钟控制器.该时钟控制器采用内置RTC的原理,通过温度补偿晶体的频偏和校准秒脉冲的输出等方式得到精准的时钟.试验数据表明,通过温度补偿晶体的频偏和秒脉冲输出校准方法相结合,使RTC时钟在(-40℃,85℃)温度范围内的误差小于0.5 s/d.该RTC时钟控制器目前已应用于国网二代三相多功能电能表.

Application of the Built-in RTC Serving as the Clock Inside Watt-hour Meters

In order to reduce the cost of the watt-hour meters,and enhance the accuracy of the clock inside the meter,the real-time clock(RTC) controller based on ST micro controller has been designed.In this clock controller,by adopting built-in RTC principle,through temperature compensating the frequency offset of crystal,and calibrating the output of second pulse,precise timing is implemented.The experimental data show that the combination of temperature compensation for frequency offset,and calibration for second pulse output makes the error of the RTC less than 0.5s/d within the temperature range of-40℃ to 85℃.This controller has been used in the 2nd generation of three-phase watt-hour meters for the State Grid at present.