摘要
传统的磁轴承功率放大器使用一个H桥控制一个线圈,为减少桥臂数量,可通过矢量控制技术共用部分桥臂。研究了一种使用三个桥臂同时控制两个线圈的功率放大器,通过FPGA实现了空间矢量脉宽调制(SVPWM)算法,将绝缘栅双极型晶体管的使用数量减少了25%。针对实际运行过程中可能出现的功率放大器指令信号超出跟踪范围的情况,通过分析三桥臂电路功率放大器的跟踪范围,指出沿用传统的占空比限制策略将导致功率放大器的性能无法被完全利用,使失真增大。本文改进了传统的占空比限制策略,使功率放大器的性能利用率达到了100%,最高可完全消除一路线圈的失真,并在此基础上提出了两种性能不同的占空比限制策略。实验结果表明:指令信号在跟踪范围内时,功放跟踪效果良好;超出跟踪范围后,两限制策略均有效且达到了设计性能。
One H-bridge is used to control one coil in a traditional magnetic bearing power amplifier. In order to reduce the number of bridge arms, some of the bridge arms can be shared with vector control technology. In this paper, a power amplifier using three-leg circuit to control two coils simultaneously is studied, and the space vector pulse width modulation(SVPWM) algorithm is implemented with FPGA, which reduces the number of IGBT by 25%. Aiming at the possibly occured situation that the command signal of power amplifiers may exceed the tracking range, this paper analyzes the tracking range of the power amplifier with a three-leg circuit, and points out that the performance of the power amplifier can not be fully utilized using traditional duty cycle restriction strategies and the distortion will be increased. This paper improves the traditional duty cycle restriction strategy, which makes the utilization ratio of the power amplifier reach 100%, and can completely eliminate the distortion of one coil at most. On this basis, two duty cycle restriction strategies with different performance are proposed. Experiment results show that the power amplifier works well when the command signals are within the tracing range, and both duty cycle restriction strategies are effective and achieve the design performance when the command signals are out of the tracking range.
作者
王纯一
徐旸
张剀
Wang Chunyi;Xu Yang;Zhang Kai(Department of Engineering Physics,Tsinghua University,Beijing 100084,China)
出处
《仪器仪表学报》
EI
CAS
CSCD
北大核心
2021年第1期248-256,共9页
Chinese Journal of Scientific Instrument
基金
国家重点研发计划项目(2018YFB2000100)
国家自然科学基金项目(51775292)资助。
关键词
功率放大器
三桥臂电路
空间矢量脉宽调制
占空比限制策略
power amplifier
three-leg circuit
space vector pulse width modulation
duty cycle restriction strategy
