适用于微机保护的模数变换器新方案探讨  

A NEW APPROACH OF ANALOG TO CONVERTER USING VOLTAGE TO FREQUENCY CONVERSION TECHNIQUE SUITABLE TO MICROPROCESSOR BASED PROTECTION SYSTEMS

作　　者：张振华[1] 王绪昭[1] 杨奇逊[1] 

机构地区：[1]华北电力学院电力工程系

出　　处：《华北电力学院学报》1989年第3期1-6,共6页

摘　　要：本文提出了一种新的应用电压频率变换技术的模数变换方案。常规的A/D方案是先加一个采样保持器将信号离散化,然后进行模数变换,因而变换时间必须小于采样间隔,这就限制了积分型A/D在要求采样频率较高的场合的应用。本文提出的方案的特点是不需要采样保持器。分析指出,该方案具有精度高、同CPU的接口简单、抗电磁干扰能力强等优点,因而特别适用于微机型继电保护装置。A new approach of A/D using voltage to frequency convertion technique is Proposed. In coventional A/D schemes, a S/H unit is used prior to A/D, therefore the converting time must be less than the sampling period. This limits the application of integral type A/D in areas where high sampling frequency is required. This paper proposes a new technique where no S/H is necessary. It is found that the method has a number of advantages, such as high accuracy, minimal interfacing with CPU, high EMI immunity. Hence it is particularly suitable to microprocessor based protection systems.

关 键 词：继电保护 模数变换 

分 类 号：TM77[电气工程—电力系统及自动化]