Development of High Performance PWM Cycloconverters

脉宽调制交交变频器是一种采用脉宽调制的交-交直接变频器，具有以下特点：(1)无储能，具有小型化、轻量化的可能；(2)由于串联的开关器件数量较少，因此效率高。(3)为了获得高性能的PWM周波变流器，对其进行了研究，取得了以下成果：(1)针对PWM周波变流器的PWM模式控制，建立了降低输入电流高频分量、获得最大输出/输入电压比的模式。(2)利用购买的数字功率表进行了实验，测量了输入功率、输出功率和效率。显示了高效率的可能性。(3)输出电流控制是将输出电流和输出电流基准送入控制元件，作为输出电压基准。控制元件由主预测控制和辅助PL控制组成。(4)实现了带电流检测的输出电流变送器。(5)实现了(3)和(4)的输出电流，具有较小的暂态振荡，获得了满意的特性。(6)采用开环控制实现了不平衡输入电压控制。闭环控制处于挂起状态。该研究结果已在IEEJ上发表。

PWM cycloconverter is an ac-to-ac direct frequency changer with PWM ( Pulse Width Modulation ) and has following features.(1) It has no energy storages and has possibilities to become small and light. (2) It has high efficiency as it has less number of series connected switch devices. (3) It is complex to control it.The PWM cycloconverter is studied to attain high performances, and results are as follows: (1) For PWM pattern control of the PWM cycloconverter, pattern making was estabilished which reduces higher frequency components of input currents and obtains maximum output to input voltage ratio. (2) Experiments were carried out and input power, output power, and efficiency were measured with the bought digital power meter. Possibility of high efficiency was shown. (3) Output current control was realized by delivering the output current and the output current reference into a control element to make the output voltage reference. The control element consists of main predictive control and supplementary pl control. (4) The output current changer with current detection was attained. (5) Output current with (3) and (4) was realized and the satisfactory charac-teristics were obtained with small transient oscillation. (6) Unbalanced input voltage control was realized with open loop control. The closed loop control is pending. The results were pubished in IEEJ.