基于电感配置的两并联变流器四电平化模型预测控制
Four-level predictive control of two parallel converters based on inductance configuration
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摘要: 两并联变流器运行中常存在环流与并联电流纹波难以兼顾的问题。本文提出一种基于电感配比的两并联变流器分步模型预测控制方法:通过交流侧滤波电感1:2配比配置,在不增加功率器件电平数的前提下,使64种开关组合经矢量去重得到37个等效基本矢量,输出矢量平面呈现四电平化特征。在此基础上,建立并联电流与三相环流离散预测模型,先按电流纹波目标对矢量排序,再在三相与零序环流峰值阈值约束下筛选冗余组合,实现纹波与环流协同优化且计算量可控。仿真结果表明,在等效滤波电感与等效开关频率一致条件下,所提方法相较1:1电感配比的交错载波空间矢量调制(ISVM)可进一步降低并联电流纹波指标并显著抑制零序环流峰值。Abstract: A common challenge in dual parallel converter operation is the difficulty in balancing circulating current and parallel current ripple. This paper proposes a stepwise model predictive control method for dual parallel converters based on inductor ratio matching. By configuring AC-side filter inductors with a 1:2 ratio, the method achieves 37 equivalent basic vectors through vector deduplication from 64 switching combinations without increasing power device levels, resulting in a four-level output vector plane. Building on this foundation, a discrete predictive model for parallel current and three-phase circulating current is established. The method first ranks vectors according to current ripple targets, then filters redundant combinations under constraints of three-phase and zero-sequence circulating current peak thresholds, achieving coordinated optimization of ripple and circulating current while maintaining controllable computational complexity. Simulation results demonstrate that under conditions where the equivalent filter inductors and switching frequencies are consistent, the proposed method significantly reduces parallel current ripple metrics and suppresses zero-sequence circulating current peaks compared to the 1:1 inductor ratio interleaved carrier space vector modulation (ISVM).
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