| 引用本文: | 肖华锋,刘隰蒲,过 亮,王 彤.规模化并网逆变器网侧谐振电流信息的小波包提取方法[J].电力自动化设备,2016,36(1): |
| XIAO Huafeng,LIU Xipu,GUO Liang,WANG Tong.Grid-side resonant current information extraction by wavelet packet for massive grid-connected inverters[J].Electric Power Automation Equipment,2016,36(1): |
|
| 摘要: |
| 规模化并网逆变器在电网公共端并联易引起复杂的谐振现象，为了有效抑制该谐振，介绍了一种基于“检测-反馈-补偿”思路的系统控制结构。为了实现上述目标，首先需要实时准确地提取该谐振电流信息来为抑制措施提供基准。研究了基于小波包变换的最大谐振电流成分实时提取技术，提出一种基于db4小波包的小波树优化分解与重构算法，在每一层分解后采用阈值判据判定小波频段、保持频段和置零频段，下一层分解时仅对小波段进行分解。相比小波包完全分解算法，该优化算法可降低分解重构过程的运算量且不损失最大谐振电流信息量。基于DSP + FPGA控制平台在含不同谐振电流信息情况下对小波树优化算法的有效性进行了验证，并给出了基于“检测-反馈-补偿”思路的谐振电流抑制结果，实验表明优化算法可有效提取出最大谐振成分，并可用于电力电子变换器的实时控制。 |
| 关键词: 并网 逆变器 谐振 小波包 优化 分解 重构 |
| DOI： |
| 分类号: |
| 基金项目:国家自然科学基金资助项目（51207024）；教育部博士点基金资助项目（20120092120054）；江苏省自然科学基金资助项目（BK20131292）；2014年国家电网公司科技项目（524615140007） |
|
| Grid-side resonant current information extraction by wavelet packet for massive grid-connected inverters |
|
XIAO Huafeng1, LIU Xipu1, GUO Liang2, WANG Tong2
|
|
1.School of Electrical Engineering，Southeast University，Nanjing 210096，China;2.NARI Group Corporation，Nanjing 211106，China
|
| Abstract: |
| A control system based on the“detection-feedback-compensation” concept is presented，which is used to damp the resonant phenomenon easily induced at the common coupling point by the massive grid-connected inverters. The system has to extract the resonant current information timely and accurately for the compensation action. The real-time resonant current extraction technique based on wavelet packet transform is studied and an optimized wavelet tree decomposition and reconstruction algorithm based on db4 wavelet packet is proposed，which applies a criterion to detect the wavelet band，hold-on band and zeroing band at each decomposition layer and only decomposes the wavelet band at the next decomposition layer until the maximum resonant component is picked out. Compared with the complete decomposition algorithm，the proposed algorithm significantly reduces the computation time，without any information loss of the maximum resonant current. The validity of the proposed algorithm is verified on a DSP + FPGA control platform in different resonant conditions. The results of resonant current restraint experiment show that，the proposed algorithm extracts the maximum resonant component effectively and it can be applied to the real-time control of power electronic converter. |
| Key words: grid-connection electric inverters resonance wavelet packet optimization decomposition reconstruction |
