基于改进型PR调节器的三相PWM整流器控制

2015-07-28 12:57:07杨尚霖王君艳
现代电子技术 2015年11期

杨尚霖 王君艳

摘 要: 应用三相PWM整流器在两相静止坐标系下电流矢量αβ分量的可解耦控制,解决了传统的基于两相旋转坐标系下三相PWM整流器控制系统电流矢量dq分量无法解耦控制的问题,提高了系统的控制性能。且采用改进型PR调节器控制代替传统的PI调节器控制能够对指定频率的交流信号实现稳态无静差跟踪控制,有效抑制低次谐波和高次谐波;相比于传统PR调节器对于系统波动过于敏感的特点,改进型PR调节器在能够保持谐振频率处的敏感度和高增益的基础上,可以增强系统稳定性。对此系统进行Matlab/Simulink仿真分析,验证了该方法的可行性。

关键词: 改进型PR调节器; 三相PWM整流器; 无静差控制; 谐波抑制

中图分类号: TN61?34; TM461 文献标识码: A 文章编号: 1004?373X(2015)11?0152?04

Three?phase PWM rectifier control based on improved PR regulator

YANG Shang?lin, WANG Jun?yan

(School of Electronic Information and Electrical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China)

Abstract: The decoupling control of current?vector αβ components in two phase static coordinate system of three?phase PWM rectifier is applied, which solved the problem that current?vector dq components cant be decoupled with two?phase rotating coordinate system in traditional three?phase PWM rectifier control system, and improved the control performance of the system. Astatic error tracking control of specified frequency AC signal can be realized with the improved PR regulator control instead of traditional PI regulator control, so the low?order and high?order harmonics are restrained efficiently. Compared with the character of the traditional PR regulator which is over?sensitive to system fluctuation, the sensitivity and high?gain at resonance frequency are maintained by PR regulator, and stability of the system is strengthened. The feasibility of the proposed method was verified by Matlab/Simulink simulation analysis.

Keywords: improved PR regulator; three?phase PWM rectifier; astatic error control; harmonic suppression

0 引 言

三相电压型PWM整流器可以实现网侧电流正弦化、单位功率因数运行及能量双向流动等功能。传统的基于两相旋转坐标系下三相PWM整流器数学模型构成的控制系统存在电流矢量dq分量控制未完全解耦的缺点,影响控制效果[1]。本文所研究的控制系统应用了三相PWM整流器在两相静止坐标系下电流矢量αβ分量可解耦控制的这一特点,且控制器采用改进型PR调节器代替传统PI调节器。

通过应用改进型PR调节器适当降低了给定频率附近的增益,适当增加带宽,增强系统的抗干扰能力,实现增益与稳定的平衡。

1 改进型PR调节器的原理

传统PR调节器的传递函数为:

[G1(s)=2Krss2+ω20] (1)

式中:[ω0]为谐振频率,在本文中取电网频率50 Hz,即100[π];[Kr]为比例系数。……

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