| 引用本文: | 江友华,曹以龙,龚幼民.串联H桥多电平变换器平衡特性研究[J].电力自动化设备,2004,(8):34-37 |
| .The research of balance characteristic about cascaded connected H bridge multilevel converters[J].Electric Power Automation Equipment,2004,(8):34-37 |
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| 摘要: |
| 近年来，串联H桥多电平变换器在高压大功率应用场合越来越受到重视，然而这种拓扑结构随着控制策略的不同，存有系统工作不平衡问题。如在梯形波调制方式中，就会有各个H桥单元直流电源功率不平衡；而在选择谐波消去脉冲宽度调制SHEPWM(Selected Harmonic Eliminate Pulse Width Modulation)方法中，则有各个H桥单元功率开关管开关次数不相等和导通负荷不一致等问题，因此在梯形波调制策略中，利用串联H桥合成输出电平开关状态冗余的特点，给出了一种在一个输出周期内就可以实现各桥直流电源功率平衡的方法，便于减小中间直流电压波动和直流电容体积．而针对传统的SHEPWM方法存在各个H桥单元功率开关管开关次数不相等和导通负荷不一致问题．给出了一种变载波频率的SHEPWM方法使得各H桥开关管开关次数相等，这样各串联H桥功率开关管就可以得到充分利用以及各H桥直流电源充放电次数相等。最后，通过频谱分析，验证了这些方法的可行性。 |
| 关键词: 串联H桥多电平 梯形波 选择谐波消去脉冲宽度调制方法 功率平衡 |
| DOI： |
| 分类号:TM76 |
| 基金项目:上海市博士建设基金(k07) |
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| The research of balance characteristic about cascaded connected H bridge multilevel converters |
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JIANG You-hua CAO Yi-long GONG You-min
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| Abstract: |
| Cascaded connected H bridge multilevel converters are becoming an attractive topology for high voltage high power applications. However,it has the power balance problem of the DC power sources and the numbers of switch are not equal with different control strategies. For exam-ple,in staircase method,it exists imbalance power of DC sources in different H bridges,in SHEPWM(Selected Harmonic Eliminate Pulse Width Modulation) approach,there are unequal numbers of switch in different H bridges. A novel method which can balance the power of DC sources in one cycle and another approach equal the numbers of switch in different H bridges by changing carriers are proposed in this paper. Finally,simulation of output waveforms spectrum is present. This project is supported by the Postdoctoral Science Foundation of Shanghai(k07). |
| Key words: cascaded H bridge multilevel,staircase waveform,SHEPWM,power balance |
