The invention relates to a reverse flux-weakening control type intelligent permanent
magnet contactor with no
position sensor, which mainly comprises a
microprocessor, a
rectifier and filter circuit, a control
voltage detection module, switch control circuits, power switches, a coil
voltage / current detection circuit, a switch power supply circuit, a
standby power supply control module and the like. A first switch
control circuit drives a power switch Q1 to be conducted with a power switch Q3 to realize the forward flux increasing of a coil; and a second switch
control circuit drives a power switch Q2 to be conducted with a power switch Q4 to realize the reverse
flux weakening of the coil. The
voltage and current signals of the coil are detected in real time to estimate the real-
time displacement signals of a movable iron core during the closing of the
contactor to realize a detection method without using a
position sensor. Through the feedback of the displacement signals of the movable iron core, by adopting the reverse flux-weakening control strategy, the detection-feedback-regulation-control intelligent
closed loop operation is realized in the closing process of the
contactor, the dynamic attractive force and the counter force of the permanent
magnet contactor are in good matching, the primary bounce and the secondary bounce of the contact are reduced, and the electrical service life and mechanical service life of the contactor are improved.