| 摘要 |
PURPOSE:To improve the characteristics immediately before stoppage by making a connection between full joints of a driving power supply with 100% ON duty at the time of driving and repeating control of load regulating joint, between 2 for four-phase excitation and 3 for five-phase excitation, with a set ON duty lower than 100%. CONSTITUTION:When a switching is made from four-phase excitation to five- phase excitation, joint of A and D phases is switched to positive pole under 50% load and thereby the joint of A and D phases goes (-) due to the electromotive force of A and D phases upon turn OFF. Consequently, a voltage 2Roio is applied on phase A and the potential across phase A goes (+) upon turn ON thus applying no voltage. At the time of five-phase excitation, switching speed is very high and the voltage of phase A increases a little and then decreases a little. The voltage of phase A increases gradually while repeating the increase and decrease operations and subsequently settles at a stable point. It settles under a current state where phase A = phase D = phase B = 0.8io. Consequently, smooth switching of excitation is carried out without causing damping of current. |
