PWM Switching Technique for Three-Phase Bidirectional Grid-Tie DC–AC–AC Converter With High-Frequency Isolation
PWM Switching Technique for Three-Phase Bidirectional Grid-Tie DC–AC–AC Converter With High-Frequency Isolation
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DOI：
10.1109/tpel.2017.2668441
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发表时间：
2018
影响因子：
6.7
通讯作者：
M. A. Sayed;Kazuma Suzuki;T. Takeshita;W. Kitagawa
中科院分区：
文献类型：
--
作者：
M. A. Sayed;Kazuma Suzuki;T. Takeshita;W. Kitagawa
基于电流隔离的高频变压器在双向DC/AC转换器中变得非常有吸引力。本文提出了一种新的脉宽调制（PWM）开关技术，用于控制双向隔离DC-AC-AC变换器采用高频链Transformer。建议的PWM技术有能力控制输入直流电流，并注入一个正弦的三相电流在单位功率因数的电网。初级侧是一个H桥转换器，用于将直流电压转换为高频方波单相电压。二次侧为矩阵变换器，用于将电网三相电压转换为高频单相波形。DC-AC-AC转换器利用高频链路Transformer实现H桥和矩阵转换器之间的电流隔离，以替代体积庞大的工频变压器（50/60 Hz）。双向功率流由高频Transformer的初级和次级电压之间的相移角控制。沿着给出了数学模型、电路工作模式和电压可控极限。通过一个200 V/1 kW的实验室样机系统，实验证明了所提出的PWM开关技术的可行性和数学模型的准确性。
Galvanic isolation based high-frequency transformers have become very attractive in bidirectional dc/ac converters. This paper presents a new pulse width modulation (PWM) switching technique for controlling a bidirectional isolated dc–ac–ac converter employing a high-frequency link transformer. The proposed PWM technique has the ability to control the input dc current and to inject a sinusoidal three-phase current to the grid at unity power factor. The primary-side is an H-bridge converter used to convert the dc voltage to a high-frequency square-wave single-phase voltage. The secondary side is a matrix converter used to convert the grid three-phase voltage to a high-frequency single-phase waveform. The dc–ac–ac converter utilizes a high-frequency link transformer for the galvanic isolation between the H-bridge and matrix converters as alternative for the bulky line-frequency transformers (50/60 Hz). The bidirectional power flow is controlled by the phase shift angle between the primary and secondary voltages of the high-frequency transformer. The mathematical model and the circuit operational modes are presented along with the voltage controllable limit. The feasibility of the proposed PWM switching technique and the accuracy of the mathematical model are demonstrated experimentally by using a 200 V/1 kW laboratory prototype system.