中压三电平并网逆变器断续脉宽调制策略及其输出滤波器优化设计

发布时间：2018-03-05 20:42

本文选题：中压三电平逆变器　切入点：断续脉宽调制　出处：《中国电机工程学报》2015年17期 　论文类型：期刊论文

【摘要】：在中压大功率并网逆变器中,存在开关频率低、输出滤波器设计困难等问题。采用断续脉宽调制策略(discontinuous pulse-width modulation,DPWM)能在保证开关损耗不变的前提下,有效提高逆变器等效开关频率、降低滤波器设计难度。首先,对6种三电平DPWM(DPWM0、DPWM1、DPWM2、DPWM3、DPWMA、DPWMB)的各自优缺点进行比较分析,结果表明在单位功率因数及较高调制度下,DPWMA兼具开关损耗小、共模电压与谐波畸变低的优点;其次,针对DPWMA调制策略输出谐波相对集中于第一载波带的特性,引入LLCL滤波器拓扑,并基于选频思想提出一种改进阻尼方案,在有效提高载波频率处谐波衰减能力的同时,确保谐振抑制能力且显著降低阻尼电阻损耗;随后,给出了所提滤波器的参数设计原则及其详细流程。对30 k W样机进行实验,实验结果表明,采用该文所提调制策略和滤波器设计方法,逆变器的输出共模电压和并网电流谐波含量能够得到有效降低,同时阻尼电阻损耗较小,有利于减小中压大功率逆变器的网侧滤波器体积与成本,提高系统效率。
[Abstract]:In the medium voltage and high power grid-connected inverter, the switching frequency is low, the output filter is difficult to design and so on. The discontinuous pulse-width modulationDPWM can effectively improve the equivalent switching frequency of the inverter under the premise of keeping the switching loss constant. First of all, the advantages and disadvantages of six kinds of three-level DPWM0 / DPWM1DPWM2DPWM3DPWM3DPWMA-DPWMBs are compared and analyzed. The results show that DPWMA has the advantages of low switching loss and low common-mode voltage and harmonic distortion under the unit power factor and higher modulation system. In view of the characteristic that the output harmonics of DPWMA modulation strategy are relatively concentrated in the first carrier band, the topology of LLCL filter is introduced, and an improved damping scheme is proposed based on the idea of frequency selection, which can effectively improve the harmonic attenuation ability at the carrier frequency. The resonant suppression ability is ensured and the damping resistance loss is significantly reduced. Then, the design principle of the parameters and the detailed flow chart of the proposed filter are given. The experimental results of the 30kW prototype show that, Using the modulation strategy and filter design method proposed in this paper, the harmonic content of the output common-mode voltage and grid-connected current of the inverter can be reduced effectively, and the damping resistance loss is small. It can reduce the size and cost of the grid-side filter and improve the system efficiency.
【作者单位】：合肥工业大学电气与自动化工程学院;合肥阳光电源有限公司;
【基金】：“十二五”国家科技支撑计划项目(2012BAA01B04)~~
【分类号】：TM464;TN713

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