摘要
针对微机继电保护电压、电流发生器功率放大出现的非线性失真现象,提出了一种基于结型场效应管(JFET)可变电阻的非线性补偿方法。首先介绍了电压、电流发生器的总体结构和功率放大的原理,并分析了JFET的压控可变电阻特性,设计了一种增益可变的运算放大电路,最后对电路进行了实验分析,结果表明非线性可变增益运算放大电路能够较好地补偿电流功率放大的非线性失真,使功率放大的线性精度得到改善,电压电流输出精度高、线性度好,满足微机继电保护实验仪的要求。
By considering the nonlinear distortion phenomenon in the power amplification of voltage and current generator for microcomputer relay protection,a nonlinear compensation method based on JFET variable resistor is proposed in this paper.The principle of power amplification and whole system structure of voltage and current generator are introduced firstly.Then the characteristics of JFET variable resistor is analyzed in detail,and a kind of calculation and magnification circuit with variable gain is designed.In the end,the experimental analysis is carried out on this circuit,and results show that nonlinear calculation and magnification circuit with variable gains can compensate the nonlinear distortion of current power amplification,the linear precision of power amplification is improved,and the output of voltage and current has high accuracy and good linearity,which meets the requirements of experimental instrument for microcomputer relay protection.
出处
《现代电力》
北大核心
2013年第1期22-26,共5页
Modern Electric Power
关键词
非线性
功率放大
可变电阻
继电保护
JFET
nonlinearity
power amplification
variable resistor
relay protection
JFET
