| 摘要 |
PURPOSE:To prevent the production of a harmonic current by detecting an overcurrent at the primary side of an inverter transformer, thereby limiting an instantaneous current and adding an analog system control loop through a PI regulator. CONSTITUTION:The output voltage of a load 38 is detected by a voltage detector 42 through a transformer 40 for an instrument, and the obtained detection signal is used to control the firing angle of inverters 32, 32 by firing angle regulator 46 through a PI regulator 44. A current detector 50 is connected through current transformers 48, 48 to the primary side of an inverter transformer 34, and the detection signal obtained by a current detector 50 is inputted to a comparator 52 and a PI regulator 54. The comparator 52 detects the abrupt rising current, thereby controlling directly the regulator 46, and minimizing the conducting angle of the inverter 32. A PI regulator 54 controls in an average the output voltage of the inverter 32. |
