NPC三电平逆变器最优化虚拟电压矢量控制

发布时间：2018-06-19 14:44

本文选题：三电平逆变器 + 中点电位平衡　；参考：《电力系统自动化》2017年18期

【摘要】：三电平逆变器的中点电位不平衡不仅使开关管的电压应力增加,还会导致输出电流的谐波畸变率增高。因此,三电平逆变器的中点电位平衡控制一直是国内外学者的研究热点。以中点钳位型(NPC)三电平逆变器作为研究对象,提出了一种最优化虚拟电压矢量中点电位平衡控制方法。该方法首先以三电平逆变器固有的有限个离散电压矢量为基础,构造出连续的虚拟电压矢量。然后以参考电压和中点电位平衡为控制目标定义代价函数,此代价函数可以灵活方便地控制逆变器的综合性能。由最优化方法求解出使代价函数值最小的虚拟电压矢量,即为控制参考电压和中点电位平衡的全局最优解,此方法不仅可以保证输出电压有较好的跟踪效果,还具有较强的中点电位平衡能力和抗干扰能力。仿真和实验都对此进行了有效的证明。
[Abstract]:The unbalanced neutral point potential of the three-level inverter not only increases the voltage stress of the switch, but also increases the harmonic distortion rate of the output current. Therefore, the neutral-point potential balance control of three-level inverter has been a hot research topic at home and abroad. An optimal virtual voltage vector neutral-point potential balance control method is proposed for a three-level NPC inverter with neutral-point clamping as an object of study. Firstly, based on the finite discrete voltage vectors inherent in the three-level inverter, a continuous virtual voltage vector is constructed. Then the cost function is defined with reference voltage and midpoint potential balance as the control objective. This cost function can flexibly and conveniently control the comprehensive performance of the inverter. The virtual voltage vector with minimum cost function is solved by the optimization method, which is the global optimal solution to control the balance of reference voltage and midpoint potential. This method can not only ensure the output voltage has a better tracking effect. It also has strong midpoint potential balance ability and anti-interference ability. Both simulation and experiment have proved this to be effective.
【作者单位】：输配电装备及系统安全与新技术国家重点实验室(重庆大学);
【分类号】：TM464

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