Development of High Performance PWM Cycloconverters

PWM变换器是一种带PWM（脉宽调制）的交流直接变频器，具有以下特点。(1)它没有能量储存，有可能变得小而轻。(2)串联开关器件少，效率高。控制它很复杂。对PWM环变换器进行了高性能的研究，研究结果如下：(1)针对PWM环变换器的PWM模式控制，建立了减少输入电流高频分量的制图方法，获得最大的输出输入电压比。(2)用所购数字功率计进行实验，测量输入功率、输出功率和效率。表明了高效率的可能性。(3)输出电流控制是通过将输出电流和输出电流基准送入控制元件，使输出电压基准。控制元件由主预测控制和辅助预测控制组成。(4)得到具有电流检测功能的输出变流器。(5)实现了(3)和(4)的输出电流，在瞬态振荡较小的情况下获得了满意的特性。(6)采用开环控制实现不平衡输入电压控制。闭环控制挂起。研究结果发表在IEEJ杂志上。

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.