张永昌 彭玉宾 曲昌琦（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）



不平衡电网电压下的PWM整流器预测电流控制

张永昌 彭玉宾 曲昌琦
（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）

摘要传统的PWM整流器预测电流控制在理想电网下能够取得良好的动、静态性能，具有开关频率固定、动态响应快和谐波小等优点，但在不平衡电网下会带来电流畸变、功率脉动和直流母线电压波动等问题。基于一种新型瞬时功率理论提出在理想电网和不平衡电网下都能够获得良好性能的改进预测电流控制。该方法以得到正弦网侧电流、消除有功二倍频波动为控制目标，通过解析推导得到相应的电流参考值，然后基于电流无差拍原理得到下一时刻的电压参考值，进而用空间矢量调制来合成该参考电压矢量。相比现有基于传统瞬时功率理论和正负序分解的解决方案，所提出的改进预测电流控制无需复杂的正负序提取计算和功率补偿算法，能够有效抑制功率波动和电流谐波，具有较大的实用价值，其有效性通过仿真和实验得到验证。

关键词：PWM整流器 电网电压不平衡 新型无功功率 预测电流控制

国家自然科学基金（51577003、51207003、51347004）和北京市科技新星计划（XX2013001）资助项目。

Predictive Current Control of PWM Rectifier under Unbalanced Grid Voltage Condition

Zhang Yongchang Peng Yubin Qu Changqi
（Power Electronics and Motor Drives Engineering Research Center of Beijing North China University of Technology Beijing 100144 China）

Abstract Conventional predictive current control (PCC) for PWM rectifiers can achieve good steady state and dynamic response under ideal grid voltage conditions, which features fixed switching frequency, quick dynamic response and low harmonics. However, under unbalanced grid voltage conditions, conventional PCC has the problems of current distortion, power oscillation and dc-bus voltage ripple. Based on a novel instantaneous power theory, this paper proposes an improved PCC strategy that is effective under both ideal and unbalanced grid voltage conditions. The control aim is to achieve sinusoidal grid currents and eliminate twice grid frequency oscillations in active power. After deriving the analytical current reference, the converter voltage vector reference in the next control period is obtained based on the principle of deadbeat current control, which is subsequently synthesized using space vector modulation (SVM). Compared to the existing solutions, the proposed PCC does not require the complex sequence extraction or power compensation algorithm. It can effectively reduce the power oscillation and current harmonics. The effectiveness of the proposed method is confirmed by both simulation and experimental results.

Keywords：PWM rectifier, unbalanced grid voltage，new reactive power，predictive current control

0 引言

PWM整流器控制在理想平衡电网下得到了广泛深入的研究，目前已经提出的方案包括电网电压定向控制（Voltage Oriented Control, VOC）[1]、直接功率控制（Direct Power Control, DPC）[2-4]和模型预测控制（Model Predictive Control, MPC）[5-9]等。VOC通过旋转变换将网侧三相电流解耦成有功电流和无功电流分量，从而分别构成有功电流和无功电流的闭环控制。……