| 摘要 |
PURPOSE:To dissolve unbalance of output voltages of a polyphase inverter to an unbalance load by a method wherein output currents are detected at every phase, and the IR compensations are performed respectively. CONSTITUTION:The output voltages of the inverter 1 are detected by a transformer 2 and a voltage detecting circuit 3, and the voltages between respective phases are averaged. A DC voltage proportional to this averaged value is check as a feed back signal VF to form the difference 6 between the reference voltage VR and is inputted as a control signal to a computing element 13. The computing element 13 adds this voltage control signal and a voltage compensating signal of each phase at every phase, and the result is inputted to a control circuit 9 through an A/D converter 8. A clock signal generating part 10 puts out a clock signal to close an analog switch 12U of U phase at timing to decide an igniting signal of U phase to send a feed back signal being added with an IR compensating signal proportional to a current flowing in U phase to the A/D converter 8. Accordingly, IR compensation for each phase can be performed, and unbalance of the output voltages to the unbalance load can be dissolved. |
