| 摘要 |
PURPOSE:To reduce the capacity of an active filter by limiting the output phase voltages of the phases of the filter, and superposing the exceeded part of the limited value on the output phase voltage of other two phases. CONSTITUTION:A 3-phase load current flowing to a load 7 is detected by current transformers 8a-8c, and input through basic Lave removing circuits 9a-9c to adders 10a-10c to be added with the outputs of current transformers 6a-6c. The outputs of the adders 10a-10c are applied through amplifiers 11a-11c and adders 12a-12c to limiters 14a-14c. The limited outputs are input to a PWM wave forming circuit 13 through adders 16a-16c. The adders 16a-16c superpose the value exceeding the limited value of the limiter of other two phases on the output phase voltages of the limiters 14a-14c. |
