| 引用本文: | 王汝田,王建赜,谭光慧,纪延超.基于重复控制的新型三相变换器研究[J].电力自动化设备,2008,(6): |
| .Study of three-phase converter with repetitive control[J].Electric Power Automation Equipment,2008,(6): |
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| 摘要: |
| 中间直流侧的电解电容是决定AC/DC/AC变换器使用寿命的关键,取消或减小该电容具有重大意义。针对整流级采用二极管不控整流桥、逆变级采用全控桥的拓扑结构,具体分析了整流级在SPWM调制方式下的工作模式。通过把三相输出电压划分为6个区间,并在每一个区间内根据SPWM的调制特点和三相负载电流的波形,得出了负载功率因数角与能量反馈(倒灌电流)的关系。在此基础上,通过对1个载波周期内直流侧电容上的充放电分析,给出了有倒灌电流时最小电容值的计算方法。取消或减小直流侧电容后,不控整流输出的直流电压是波动的,逆变级不能直接应用标准的SPWM。根据重复控制的原理,对重复控制可以消除输出电压中因直流电压波动而产生的低次谐波的机理进行了分析,分析结果表明应用重复控制可以使输出电压具有良好的波形。最后,应用Matlab/Simulink进行了仿真,仿真结果验证了理论分析的正确性。 |
| 关键词: AC/DC/AC变换器,SPWM,重复控制,陶瓷电容 |
| DOI： |
| 分类号:TM46 |
| 基金项目: |
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| Study of three-phase converter with repetitive control |
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WANG Rutian WANG Jianze TAN Guanghui JI Yanchao
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| Abstract: |
| Since DC-link electrolytic capacitor mainly decides the lifetime of AC/DC/AC converter,it is significant to reduce its size or even cancel it.For the topology in which the rectifier part adopts diodes and the inverter part adopts controlled switches,the working modes of inverter under SPWM are analyzed.Three-phase output voltages are divided into six intervals and the relationship between power factor of load and energy feedback of each interval is deduced on the basis of SPWM characteristics and three-phase load currents waveform.The charge-discharge process of the capacitor in one cycle is analyzed and the method of calculating its smallest capacitance is given.As the DC outputs of rectifier is fluctuant when the DC-link capacitor is cancelled or reduced,the inverter can not apply standard SPWM.The way to remove the lower harmonics caused by DC ripple from output voltage is analyzed and it shows that,fine output voltage waveform can be obtained by applying repetitive control method.Matlab simulation verifies its validity and effectiveness. |
| Key words: AC/DC/AC converter,SPWM,repetitive control,ceramic capacitor |
