Design of LCL filters in consideration of parameter variations for grid-connected converters
Design of LCL filters in consideration of parameter variations for grid-connected converters
复制标题
考虑并网变流器参数变化的LCL滤波器设计
DOI：
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发表时间：
2012
期刊：
影响因子：
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通讯作者：
A. Mertens
中科院分区：
文献类型：
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作者：
R. Meyer;A. Mertens
本文描述了一种用于并网变流器的LCL滤波器的有效设计过程。它特别适合于为开关频率较低的变流器设计在整个频率范围内产生谐波的滤波器。在这些特殊的应用中，一些微小的参数变化可能会导致超过给定的限制，如允许的电压谐波。在最坏的情况下，滤波器的谐振频率可能被激发到不可接受的程度。为了避免这种情况，在设计滤波器时考虑了滤波器参数的容差、电网电压和电网频率。这种对参数变化的基本考虑使这种新方法有别于众所周知的设计过程。以一台5 MW风电机组为例，详细介绍了全尺寸三电平中压变流器的滤波器设计。在一个大规模低压实验室装置上的测量验证了理论计算，并完成了检验。所讨论的设计过程使滤波器设计能够在考虑各种参数变化的情况下，满足所有相关运行范围的电压质量方面的所有电网规范要求。该方法适用于所有产生周期性输出电压的变流器拓扑和调制方案。
In this paper an efficient design process of LCL filters for grid-connected converters is described. It is especially developed to design filters for converters with low switching frequency generating harmonics in the entire frequency range. In these special applications, some small parameter variations can cause the given limits, like the allowed voltage harmonics, to be exceeded. In the worst case, the resonance frequency of the filter can be excited to an unacceptable extent. To avoid this, the tolerances of the filter parameters, the grid voltage and the grid frequency are taken into account when designing the filter. This essential consideration of the parameter variations distinguishes this new method from the well-known design processes. As an example, a filter design for a 5 MW wind energy generator with full-scale three-level medium-voltage converter is regarded more detailed. Measurements on a scaled low-voltage laboratory setup validate the theoretical calculations and complete the examination. The discussed design process enables a filter design meeting all grid code requirements concerning the voltage quality for all relevant operating ranges in consideration of various parameter variations. The method is suitable for all converter topologies and modulation schemes generating periodical output voltages.