高效率中点钳位型光伏逆变器拓扑比较

2011年2月电工技术学报Vol.26 No. 2 第26卷第2期TRANSACTIONS OF CHINA ELECTROTECHNICAL SOCIETY Feb. 2011
高效率中点钳位型光伏逆变器拓扑比较
马琳1,3孙凯2R emus T eodorescu3金新民1
（1. 北京交通大学电气工程学院北京 100044
2. 清华大学电力系统及大型发电设备安全控制和仿真国家重点实验室北京 100084
3. 奥尔堡大学能源技术系奥尔堡 9220）
摘要光伏逆变器是太阳能光伏发电系统的核心部件之一。

为了提高太阳辐射能的利用效率，降低光伏发电的成本，高效率的光伏逆变器拓扑已成为近年来的研究热点。

中点钳位型（NPC）三电平电路拓扑由于具有开关损耗小、电磁干扰（EMI）小、光伏阵列对地杂散电容上无共模漏电流、所需滤波电感小等优点，非常适用于单相光伏逆变器。

本文对三种典型的三电平NPC拓扑（二极管NPC、有源NPC（ANPC）和Conergy NPC）进行了全面深入的比较分析，包括调制原理、功率损耗分布、器件成本和性能特点，并通过实验测试了三种拓扑的效率。

研究结果表明：
①Conergy NPC的效率在三种拓扑中最高，且所用器件数最少；②有源NPC的功率损耗分布可以
灵活调节，有利于大功率应用场合的散热设计，但其控制比较复杂，且器件成本在三种拓扑中最高；③二极管NPC拓扑的功率损耗分布不易调节，不利于大功率应用场合的散热设计。

关键词：光伏逆变器中点钳位高效率拓扑
中图分类号：TM46
Comparison of the Topologies of High Efficiency Neutral Point
Clamping Photovoltaic Inverters
Ma Lin1,3 Sun Kai2 Remus Teodorescu3 Jin Xinmin1
（1. Beijing Jiaotong University Beijing 100044 China
2. Tsinghua University Beijing 100084 China
3. Aalborg University Aalborg 9220 Denmark）
Abstract Photovoltaic (PV) inverter is one of the key elements in photovoltaic generation system. In order to enhance the utilization efficiency of solar energy and lower the cost of PV generation, high efficiency PV inverters have obtained much more attention during recent years.
Neutral point clamping (NPC) three-level topologies have some attractive advantages, such as low switching loss, low EMI, no PV array leakage current and smaller filter inductors. Hence, NPC topologies are suitable for single-phase PV generation. In this paper, three typical NPC topologies (Diode NPC, Active NPC and Conergy NPC) are compared in detail, including modulation strategy, power loss distribution, device cost and operation characteristics. In addition, the conversion efficiencies of these three topologies are tested through experiments. The results show that: ①Conergy NPC has the highest efficiency and lowest device number among the three topologies; ②Active NPC has adjustable power loss distribution and is easy for heat sink design in high power applications, but it has complex control and the highest device cost among the three topologies; ③The power loss distribution of diode NPC can not be adjustable and has negative influence on the heat sink design in high power applications.
Keywords：Photovoltaic inverter, neutral point clamping, high efficiency, topology
台达环境与教育基金会《电力电子科教发展计划》资助课题（DREG2010007）。

收稿日期 2009-12-25 改稿日期 2010-03-05。