| 摘要 |
PURPOSE:To miniaturize the title inverter and reduct the cost of the same, by inserting a reactor between the output wires of a PWM inverter and detecting the current of the reactor by a Hall CT. CONSTITUTION:An AC machine 2 is driven by a PWM inverter 1. The control circuit of the inverter 1 is constituted of a flux regulator 3, a comparator 4, a base driving circuit 5 and a flux detecting circuit 6 to detect the actual value of the flux and output a voltage commanding value, so that the actual value of flux coincides with the commanding value of the same. In this case, the flux detecting circuit 6 is constituted of a reactor 63 and a Hall CT 64. A current flowing through the reactor 63, can be deemed as the flux having the integral value of the output voltage of the inverter 1; therefore, the actual values phiR-phiT of the flux can be obtained by detecting the current by the Hall CT 64. According to this method, detection, low in cost and excellent in frequency characteristics, may be effected. |
