Single-Phase High Step-up Converter With Improved Multiplier Cell Suitable for Half-Bridge-Based PV Inverter System
Single-Phase High Step-up Converter With Improved Multiplier Cell Suitable for Half-Bridge-Based PV Inverter System
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DOI：
10.1109/tpel.2013.2273975
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发表时间：
2014-06
影响因子：
6.7
通讯作者：
Yi Zhao;Xin Xiang;Chushan Li;Yunjie Gu;Wuhua Li;Xiangning He
中科院分区：
文献类型：
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作者：
Yi Zhao;Xin Xiang;Chushan Li;Yunjie Gu;Wuhua Li;Xiangning He
本文提出了一种单相高压升压变换器，不仅可以将相对较低的光伏（PV）电压高效地升压到较高的母线电压，而且可以为半桥逆变器提供中性点端子。首先，两个对称的高升压转换器的组合和集成，以获得一个改进的转换器与中性点终端，这是强烈期望的半桥逆变器。其次，通过耦合电感倍增器的使用，提高了变换器的电压增益，避免了关断周期过窄的问题。此外，耦合电感倍增器降低了所有功率器件的电压应力。因此，可以采用低电压额定功率器件来最小化传导损耗。更重要的是，所有的有源开关都工作在零电压开关状态，有效地降低了开关损耗。所有这些因素都提高了电路在高升压应用中的性能，特别是对于基于半桥的光伏逆变器系统。最后，通过一台500 W，48 - 760 V，开关频率为100 kHz的样机实验验证了该变换器的有效性。样机的最高效率为96.5%，在较宽的负载范围内效率均在94%以上。
In this paper, a single-phase high step-up converter is proposed, designed not only to boost the relatively low photovoltaic (PV) voltage to a high bus voltage with high efficiency, but also to offer a neutral point terminal for the half-bridge-based inverters. First and foremost, two symmetrical high step-up converters are combined and integrated to derive an improved converter with neutral point terminal, which is strongly expected for the half-bridge-based inverters. Secondly, the voltage gain of the converter is extended and the narrow turn-off period is avoided by using the coupled inductor multiplier. Furthermore, the coupled inductor multiplier reduces the voltage stress of all the power devices. As a result, the low voltage-rated power devices can be employed to minimize the conduction losses. More importantly, all the active switches work in the zero-voltage-switching condition, which reduces the switching losses effectively. All these factors improve the circuit performance in the high step-up applications, especially for the half-bridge based PV inverter systems. Finally, the experimental results from a 500 W, 48 -760 V prototype at 100 kHz switching frequency are provided to verify the effectiveness of the proposed converter. The highest efficiency of the prototype is 96.5% and the efficiency is over 94% in a wide load range.