In the field of industrial voltage transformation,AC-AC converter has the characteristics of high power density,high efficiency and low cost.For this purpose,a bidirectional power flow three phase AC-AC converter based on switched capacitor is proposed,which can reduce or increase the output voltage.Firstly,the AC-AC converter open triangle topology is analyzed,the power level only uses capacitor and switch to improve the efficiency and increase the power density,and then gives the equivalent circuit of three-phase.In open loop operation,the gain,duty ratio and frequency of the converter are fixed values.Finally a 3.5 kW prototype is built and tested.The experimental results show that at rated load under the conditions of the proposed converter efficiency about 93.7%,the power density is 1.23 kW/kg,and the cost is lower as the less number of components required.%在工业电压变换领域,AC-AC变换器需具有高功率密度、高效率和低成本的特性.为此,提出了一种基于开关电容的双向功率流三相AC-AC变换器,该变换器为双向变换器,能够降低或者增大输出电压.首先对该AC-AC变换器的开口三角形拓扑结构进行了分析,通过功率级只使用了电容和开关,来提高效率并增加功率密度,然后给出了其三相等效电路.该变换器在开环回路中运行时,增益、占空比以及频率均为固定值.最后建构了3.5 kW样机,并对其进行测试,实验结果显示在额定负载条件下提出变换器的效率约为93.7%,功率密度为1.23 kW/kg,且所需元件数量较少,成本更低.
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