基于SHEPWM的三电平NPC逆变器中点电位平衡控制算法

发布时间：2018-05-01 04:32

本文选题：三电平逆变器 + 中性点钳位　；参考：《电力系统自动化》2017年16期

【摘要】：以三电平中性点钳位型(NPC)逆变器为对象,提出基于特定次谐波消除脉宽调制(SHEPWM)的中点电位平衡控制算法。首先介绍空间矢量脉宽调制中点电位平衡原理与SHEPWM开关角求解模型,然后分析三相SHEPWM波形在不同调制度下对应的开关矢量序列和作用角度,基于此设计了三种冗余矢量调整方案,最后通过检测负载电流与中点电位,由中点电位滞环控制器和控制逻辑组合作用,直接对三相脉宽调制信号进行在线调整,实现中点电位平衡。实验结果表明:不同的矢量调整方案具有不同的中点电位平衡速度、平均开关频率等,但均不影响线电压的谐波消除能力;采用中点电位三级滞环控制器可兼顾中点电位平衡、波形对称、共模电压幅值,且不增加器件开关次数。
[Abstract]:A neutral-point potential balance control algorithm based on special subharmonic elimination pulse width modulation (SHEMPW) is proposed for a three-level neutral point clamped NPC-inverter. This paper first introduces the principle of point potential balance in space vector pulse width modulation (SVPWM) and the solution model of SHEPWM switching angle, and then analyzes the sequence of switching vectors and the action angle of three-phase SHEPWM waveform under different modulation systems. Based on this, three redundant vector adjustment schemes are designed. Finally, by detecting the load current and the midpoint potential, the three-phase pulse width modulation signal is adjusted on-line by the combination of the midpoint potential hysteresis controller and the control logic. The midpoint potential is balanced. The experimental results show that different vector adjustment schemes have different midpoint potential balance speed, average switching frequency and so on, but all of them do not affect the harmonic elimination ability of line voltage, and the midpoint potential three-stage hysteresis loop controller can balance the midpoint potential. Waveform symmetry, common-mode voltage amplitude, and do not increase the number of switch devices.
【作者单位】：磁浮技术与磁浮列车教育部重点实验室西南交通大学;西南交通大学电气工程学院;
【基金】：国家自然科学基金资助项目(51677156)~~
【分类号】：TM464

【相似文献】