Soft-Switching AC-Link Three-Phase AC–AC Buck–Boost Converter
Soft-Switching AC-Link Three-Phase AC–AC Buck–Boost Converter
复制标题
软开关 AC-Link 三相 AC-AC 降压-升压转换器
DOI：
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发表时间：
2015
期刊：
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通讯作者：
W. Alexander
中科院分区：
文献类型：
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作者：
M. Amirabadi;J. Baek;H. Toliyat;W. Alexander
在本文中，将更详细地研究软开关交流链路交流-交流降压-升压转换器。这种单级转换器本质上是 DC-DC 降压-升压转换器的扩展，可以成为直流母线转换器的绝佳替代品。作为降压-升压转换器，该转换器能够升压和降压。链路电流和电压都是交替的，并且它们的频率可以与微控制器的开关和采样时间允许的一样高。这消除了对直流电感器或直流电解电容器的需要，并且主要的能量存储元件是交流电感器(L)。此外，在该转换器中，可以通过在链路中添加单相高频变压器来提供电流隔离。因此，与传统的直流母线转换器相比，所提出的转换器预计会更加紧凑。该转换器的另一个优点是开关的软开关，这可以通过在链路中添加一个小电容器 (C) 来实现。本文将详细研究该转换器的设计和分析。为了准确分析该转换器，将研究LC链路谐振对转换器性能的影响。当 LC 链路的谐振时间不可忽略时，此分析有助于评估转换器在低功率水平下的性能。使用该分析，可以计算任意操作点的链路峰值电流和链路频率。通过仿真和实验验证了该方法的准确性。本文还将对所提出的转换器与直流母线转换器进行详细比较。可以看出，尽管该转换器具有更多开关，但开关的额定电流较低。此外，还将比较两个转换器的效率。最后，本文对软开关交流链路交流-交流升降压转换器的性能进行了实验评估。将表明转换器具有改变频率和电压的可能性。升压和降压操作都将通过实验进行验证。
In this paper, the soft-switching ac-link ac-ac buck-boost converter will be studied in more detail. This single-stage converter, which is, in essence, an extension of the dc-dc buck-boost converter, can be an excellent alternative to dc-link converters. Being a buck-boost converter, this converter is capable of both stepping-up and stepping-down the voltage. The link current and voltage are both alternating, and their frequency can be as high as permitted by the switches and the sampling time of the microcontroller. This eliminates the need for dc inductors or dc electrolytic capacitors, and the main energy storage element is an ac inductor (L). Moreover, in this converter, galvanic isolation can be provided by adding a single-phase high-frequency transformer to the link. Therefore, the proposed converter is expected to be more compact compared to the conventional dc-link converter. The other advantage of this converter is the soft switching of the switches, which is feasible by adding a small capacitor (C) to the link. In this paper, the design and analysis of this converter will be studied in detail. In order to accurately analyze this converter, the effect of the LC link resonance on the performance of the converter will be studied. This analysis helps in evaluating the performance of the converter at low power levels when the resonating time of the LC link is not negligible. Using this analysis, the link peak current and the link frequency may be calculated at any point of operation. The accuracy of this method is verified through simulations and experiments. Detailed comparison of the proposed converter with the dc-link converter will be also presented in this paper. It will be shown that, despite having more switches, the current rating of the switches is lower in this converter. Moreover, the efficiencies of the two converters will be compared. Finally, the performance of the soft-switching ac-link ac-ac buck-boost converter is experimentally evaluated in this paper. It will be shown that the converter has the possibility of changing both the frequency and the voltage. Both step-up and step-down operations will be verified through experiments.