| 摘要 |
PURPOSE: To improve the dust collecting efficiency of an electric precipitator by individually detecting voltage between electrodes, an electrode current and the voltage and the current at a DC intermediate circuit of an inverter device and controlling the rectifier part of the inverter device so that voltage between electrodes of the electric precipitator may maintain the electric field strength critical level. CONSTITUTION: In a DC intermediate circuit combining a rectifier part 41 and an inverter 92, a DC intermediate circuit current detector 44 of a DC intermediate circuit voltage detector 43 is installed. The detected voltage and current are inputted to a controller 8. Voltage between electrodes and an electrode current of an electric precipitator 7 are detected by an interelectrode voltage detector 73 and an electrode current detector 74 to input them to the controller 8. When the controller 8 detects an abnormal discharge state such as a spark discharge one from these input signals, the voltage between electrodes is lowered to eliminate the abnormal discharge. When the abnormal discharge has been eliminated, the rectifier part 41 and the inverter part 41 are controlled so that the voltage between the electrodes may quickly reach the electric field strength critical level. |
