开关电容AC-AC变换器研究

发布时间：2018-06-12 02:52

本文选题：开关电容 + AC-AC变换器　；参考：《中国计量学院》2014年硕士论文

【摘要】：开关电容变换器主要由开关管和电容组成，能够实现电压变换和能量转换，是一种典型的无感变换器，具有体积小、重量轻、功率密度大等优点，随着电子设备的小型化发展，开关电容AC-AC变换器的应用前景将非常广阔。本文提出了一种基于开关电容原理的新型AC-AC变换器，能够实现变比为1/4或4的交流电压变换。设计给出了其电路拓扑结构，并对工作原理做了详细的分析。为研究变换器的效率问题，将电路拓扑简化成开关电容基本单元，运用一阶电路全响应原理推导出了其等效内阻表达式，并给出了其他主要电路参数的计算公式，包括等效电容、功率开关管的损耗、变换器效率等。根据其效率表达式，讨论了提高效率的几种方法，为变换器主要电路参数的选择提供了理论依据。在理论分析的基础上，建立了仿真模型，对电路拓扑结构进行仿真验证，分别进行了降压和升压仿真分析，，其结果验证了该拓扑结构的有效性。最后，根据理论分析和仿真验证的结果，设计并研制了一台500W220V/55V开关频率50kHz的原理样机，并分别进行降压和升压实验。在降压实验时，输入电压设为220V，变换器的空载输出电压为55.5V，在阻性、容性负载下，输出电压均可保持稳定，其效率最大为88.63%；在升压实验时，输入电压设为55V，变换器的空载输出电压为219.3V，效率最大为90.69%，实验结果验证了该变换器具有良好的性能。
[Abstract]:Switched capacitor converter is mainly composed of switch tube and capacitor. It can realize voltage conversion and energy conversion. It is a typical sensorless converter. It has the advantages of small size, light weight and high power density. With the development of electronic equipment, the application prospect of switched capacitor AC-AC converter will be very broad.
In this paper, a new type of AC-AC converter based on the principle of switched capacitor is proposed, which can transform the AC voltage to 1/4 or 4. The topology of the circuit is given and the working principle is analyzed in detail. The equivalent internal resistance expression is derived by the full response principle, and the calculation formulas for other main circuit parameters are given, including the equivalent capacitance, the loss of the power switch tube, the efficiency of the converter and so on. According to the efficiency expression, several methods to improve the efficiency are discussed, which provide the theoretical basis for the selection of the main circuit parameters of the converter. On the basis of the analysis, the simulation model is established, and the circuit topology is simulated and verified. The simulation analysis of the buck and boost is carried out respectively. The results verify the validity of the topology.
Finally, according to the results of theoretical analysis and simulation verification, a prototype of 500W220V/55V switching frequency 50kHz is designed and developed, and the pressure lowering and boosting experiments are carried out respectively. In the depressurization experiment, the input voltage is set to 220V, the output voltage of the converter is 55.5V, and the output voltage can be kept stable under resistance and capacitive load. The maximum efficiency is 88.63%. In the boost experiment, the input voltage is set to 55V, the no-load output voltage of the converter is 219.3V and the maximum efficiency is 90.69%. The experimental results verify the good performance of the converter.
【学位授予单位】：中国计量学院
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM46

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