电气工程学报 ›› 2016, Vol. 11 ›› Issue (11): 1-8.doi: 10.11985/2016.11.001

• •    下一篇

预测直接功率控制中的数字延迟分析及补偿策略研究

张永昌,高基豪   

  1. 北方工业大学电力电子与电气传动北京市工程研究中心 北京 100144
  • 收稿日期:2016-05-16 出版日期:2016-11-20 发布日期:2019-11-22
  • 作者简介:张永昌 男 1982年生,博士,教授,主要研究方向为电力电子与电机控制。|高基豪 男 1988年生,硕士研究生,主要研究方向为不平衡电网下的三电平PWM整流器模型预测控制。

The Analysis on Digital Delay and the Research on Compensation Strategy of Predictive Direct Power Control

Zhang Yongchang,Gao Jihao   

  1. North China University of Technology Beijing 100041 China
  • Received:2016-05-16 Online:2016-11-20 Published:2019-11-22

摘要:

电力电子变换器采用数字控制时,由于A–D转换、零阶保持以及PWM更新等延时因素会影响系统性能,严重时甚至使系统振荡不稳定。本文以PWM整流器为应用对象,研究采用基于SVM的预测无差拍直接功率控制时各个延迟因素对控制性能的影响,提出相应的补偿策略。研究表明,对控制性能影响较大的主要包括电网电压延迟、电网电流延迟和PWM输出电压延迟三个因素。详细分析和推导了电网电压和电流延迟的原因,提出采用下一时刻的预测电压和电流值进行控制的补偿方法。针对PWM输出延迟,分析和推导了零阶保持器和PWM更新机制对输出电压幅值和相位的影响,得到了解析的补偿公式。通过仿真和实验详细分析了三种延时及相应补偿策略对减小功率脉动、抑制电流谐波和消除稳态误差的影响,结果证明了所提补偿策略的正确性和有效性。

关键词: PWM整流器, 预测控制, 无差拍控制, 直接功率控制, 延时补偿

Abstract:

The delay factors such as A–D conversion, ZOH (zero order hold) and PWM update caused by digital control employed in the power electronic converter, will affect the system performance, which will cause the system oscillation and even unstable for the serious cases. With the PWM rectifier as the applied object, this paper studies the influence of each delay factor on the control performance when predictive deadbeat direct power control based on SVM is adopted, and proposes the corresponding compensation strategy. The research shows that there are three main delay factors influencing the control performance, including grid voltage delay, grid current delay and PWM output voltage delay. A compensation method adopting the predictive voltage and current value of the next time for the control system is proposed through detailed analysis and derivation of the delay reasons of the grid voltage and grid current. For the PWM output delay, the impact of ZOH and PWM update mechanism on the amplitude and phase of the output voltage are analyzed and deduced,and the analytic compensation formula is finally obtained. Three kinds of delay factors and the corresponding compensation strategies to reduce the power pulsation, to suppress the current harmonic and to eliminate the steady-state error are analyzed particularly through simulations and experiments and the results correspond to the correctness and effectiveness of the proposed compensation strategy.

Key words: PWM rectifier, predictive control, deadbeat control, direct power control, delay compensation

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