CAJ | 학술논문

电力监控仪表是一种先进的智能化、数字化的前端采集元件，该类仪表已广泛应用于各种控制系统，它在功能上取代了测量仪表及常规电力变送器。以带有谐波监测功能的电力监控仪表作为设计对象，重点讨论了采用AD421实现4mA～20mA两线制电流变送的工作原理。采用32位飞思卡尔单片机MCF51AC256B作为系统CPU，出于安全考虑AD421与单片机之间的通信接口采用6N136进行光耦隔离，文中给出了4mA～20mA电流变送设计电路以及仪表系统硬件框图。通过实验，验证了电流环路中的给定电流输出稳定、准确，环路设计方案可行、可靠。
전력감공의표시일충선진적지능화、수자화적전단채집원건，해류의표이엄범응용우각충공제계통，타재공능상취대료측량의표급상규전력변송기。이대유해파감측공능적전력감공의표작위설계대상，중점토론료채용AD421실현4mA～20mA량선제전류변송적공작원리。채용32위비사잡이단편궤MCF51AC256B작위계통CPU，출우안전고필AD421여단편궤지간적통신접구채용6N136진행광우격리，문중급출료4mA～20mA전류변송설계전로이급의표계통경건광도。통과실험，험증료전류배로중적급정전류수출은정、준학，배로설계방안가행、가고。
Electric power monitoring instrument is an advanced intelligent and digital front-end capture devices which has been widely used in various control systems and replaced the conventional power measuring instruments and trans -mitters in function.In this paper, power monitoring instrument with harmonic monitoring functions is made as a design object, the working principle of using AD421 to realize 4mA~20mA two-wire transmitter is discussed .32-bit frees-cale chip MCF51 AC256 B is used as the CPU .For security reasons , communication interface between AD 421 and CPU uses 6N136 to execute optocoupler isolation .This paper presents the design of 4mA~20mA current loop and the hardware block diagram of the meter system .Experiments verify the given current in current loop can be exported stably and accurately , the loop design is feasible and reliable .