【摘要】 中点箝位型(NPC)三电平拓扑在较高电压场合被广泛应用,三电平调制算法和中点均压控制策略是该拓扑的关键技术。此处首先分析了三电平空间矢量脉宽调制(SVPWM)和载波脉宽调制(CBPWM)方法的等效关系,指出调节小矢量作用时间与注入零序分量来调节中点电位的等效性。针对传统中点平衡方法不适用于谐波补偿的应用场合,引入基于电压参考矢量和相电流方向判断的改进方法,并给出了在两种调制策略下的等效实现方式。最后,通过实验验证了两种调制算法的等效性以及改进中点均压控制方法在谐波场合的适用性。更多还原

【Abstract】 The neutral point clamped(NPC) three-level topology has been widely used in high voltage applications.The modulation strategy and the balance of neutral point potential are the key technologies of the topology.The correlation between three-level space vector pulse width modulation(SVPWM) and carrier-based pulse width modulation(CBPWM)method is analyzed,indicating the equivalent relation between the regulation of small vector and injecting zero-sequence component.The traditional neutral point potential control strategy is adapted to meet harmonic compensation conditions based on judgement of voltage reference vector and phase current direction,and its implementation with two types of modulation is presented.Finally,the correlation between these two kinds of modulation algorithm and the improved neutral point potential control method under harmonic conditions are verified by experiments.更多还原