CAJ | 학술논문

三电平拓扑结构相对于两电平在性能上有很多优势，但是也存在中点电位不平衡这一固有问题。基于简化的三电平空间矢量脉宽调制(space vector pulse width modulation， SVPWM)，提出一种混合式的三电平中点平衡控制策略。该控制策略在低调制度下，根据中点电压偏移情况，结合三相电流，明确重叠区域的扇区选择原则，克服非冗余小矢量造成的中点偏移；高调制度下，充分考虑中矢量对中点偏移的影响，对不同的小三角形设置不同的时间控制因子，实现对中点电位平衡的精细化控制。基于 DSP 构建三电平逆变器硬件平台，在1140 V/500 kW三相异步电机和三相电感上完成了相关实验。实验结果验证了该方法可以实现全频率段中点电位的平衡控制。
삼전평탁복결구상대우량전평재성능상유흔다우세，단시야존재중점전위불평형저일고유문제。기우간화적삼전평공간시량맥관조제(space vector pulse width modulation， SVPWM)，제출일충혼합식적삼전평중점평형공제책략。해공제책략재저조제도하，근거중점전압편이정황，결합삼상전류，명학중첩구역적선구선택원칙，극복비용여소시량조성적중점편이；고조제도하，충분고필중시량대중점편이적영향，대불동적소삼각형설치불동적시간공제인자，실현대중점전위평형적정세화공제。기우 DSP 구건삼전평역변기경건평태，재1140 V/500 kW삼상이보전궤화삼상전감상완성료상관실험。실험결과험증료해방법가이실현전빈솔단중점전위적평형공제。
The three-level topology has a lot of advantages compared with the two-level one, but it also has some problems such as the neutral-point unbalance. This paper proposes a hybrid three-level neutral-point balance control strategy used for the simplified three-level Space Vector Pulse Width Modulation (SVPWM). The control strategy clearly clarifies sector selection principle based on the neutral-point voltage offset and the three-phase current under the low modulation index condition to overcome the voltage offset caused by non-redundant small vector. In high modulation index condition, it fully considers the impact of the medium vector on the neutral-point voltage offset, sets a different time controlling element for every small triangle to achieve meticulous control of neutral-point. A three-level inverter hardware platform was built based on DSP, and relevant experiments have been done on the 1 140 V/500 kW three-phase induction motor and three-phase inductor. Experimental results verified that the algorithm can achieve neutral-point balance control of a full frequency range.