| 摘要 |
PURPOSE:To prevent the erroneous operation with a simple structure by providing a current transformer at a common bus connected to an output line to detect the average value of the output currents of all inverters and correcting the phase difference between the inverters on the basis of the average value. CONSTITUTION:A deviation of effective current between inverters is calculated by an effective deviation calculator 18 from the deviation currents of the current flowed to the bus B detected through a current transformer 24 from the output currents of inverters 16 detected through a current transformer 20. The output of the calculator 18 is inputted to a signal/frequency regulator 12 to set the deviation of the effective currents to zero. A loop is formed so that the output of the regulator 12 is inputted to the regulator 12 through a frequency regulator 10, and when the output of the regulator 12 is displaced from zero, the regulator 10 controls to return its output to zero, thereby performing the fixing of the frequency. |
