基于优化调制参数的高效率双有源桥变换器研究

发布时间：2018-06-15 19:34

本文选题：双有源桥变换器 + 变压器电流有效值　；参考：《哈尔滨工业大学》2014年硕士论文

【摘要】：能源危机的日益严重提高了人们对可再生能源及其利用技术的重视，而该技术的发展离不开电力电子技术的支持。其中双向DC-DC变换器作为电源系统的充放电枢纽，，起着至关重要的作用。本文选择双有源桥变换器(Dual-active bridge converter)这种原件数量较少、功率密度较高的变换器拓扑作为研究对象，并对其效率特性进行分析研究。首先针对双有源桥变换器在不同调制模式下的工作特性进行了深入研究；其次通过研究双有源桥变换器的损耗组成和特性明确了影响其损耗的关键因素（变压器电流有效值）；之后通过对比各种调制模式下的变压器电流波形选取所有能够减小变压器电流有效值的模式，并通过比较计算得出全功率范围内最小变压器电流有效值的优化调制参数（包括高低压侧全桥电路输出电压等效占空比D1，D2和移相角）计算方式；为验证计算的准确性和优化调制模式的可行性，分别对变换器移相调制模式、三角形（梯形）电流调制模式及参数优化调制模式进行各功率等级的仿真分析；最后完成了双有源桥变换器在移相调制模式、三角电流调制模式及参数优化调制模式下的实验分析及效率对比测试，验证了本文中参数优化调制模式的有效性和可行性。与以往双有源桥变换器效率方面的研究相比，本文采用改变变压器电流波形、减小其有效值来实现变换器整体效率的提升；由于不同功率等级下效率最优的调制模式不完全相同，因此本文给出了在全功率范围内优化调制参数的计算方法；此外，在变换器的建模过程中，本文使用了基于离散时域的空间状态方法来计算变换器的控制到输出传递函数；在实验过程中，设计了由三片UCC3895构成的控制电路以完成对于三个参数变量的控制。实际实验过程中该电路运行良好，本文最终的实验结果也表明可以在不加入软开关的情况下，通过改变变换器的调制模式来提高变换器的整体效率。
[Abstract]:The increasingly serious energy crisis has raised the importance of renewable energy and its utilization technology, and the development of this technology can not be separated from the support of power electronics technology. As a charging and discharging hub of power system, bidirectional DC-DC converter plays an important role. In this paper, Dual-active bridge converters, which are few in number and high in power density, are chosen as the research object, and their efficiency characteristics are analyzed. Firstly, the characteristics of dual active bridge converters under different modulation modes are studied in depth; secondly, the key factors (transformer current RMS value) are determined by studying the loss composition and characteristics of dual active bridge converters. Then, by comparing the transformer current waveforms under various modulation modes, we select all the modes that can reduce the effective value of transformer current. The optimal modulation parameters (including equivalent duty cycle D1D _ 2 and phase-shifting angle) of the minimum transformer current in the full power range are obtained by comparison and calculation. The optimal modulation parameters (including the equivalent duty cycle D1D _ 2 and the phase-shifting angle) of the full-bridge circuit on the high and low voltage side are obtained. In order to verify the accuracy of the calculation and the feasibility of optimizing the modulation mode, the converter phase shift modulation mode, triangular (trapezoidal) current modulation mode and parameter optimized modulation mode are simulated and analyzed respectively. Finally, the experimental analysis and efficiency comparison test of dual-active bridge converter in phase-shift modulation mode, triangular current modulation mode and parameter optimized modulation mode are completed, which verifies the effectiveness and feasibility of the parameter optimization modulation mode in this paper. Compared with the previous research on the efficiency of dual active bridge converters, this paper uses changing transformer current waveform to reduce the effective value to achieve the overall efficiency of the converter. Because the optimal modulation modes at different power levels are not identical, this paper presents a calculation method for optimizing modulation parameters in the full power range. In addition, in the modeling process of the converter, In this paper, a discrete time-domain spatial state method is used to calculate the control to output transfer function of the converter. In the experiment, a control circuit composed of three UCC3895 is designed to control the three parameter variables. The experimental results show that the modulation mode of the converter can be improved by changing the modulation mode of the converter without soft switching.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM46

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