Reverse flux-weakening control type intelligent permanent magnet contactor with no position sensor

Abstract

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.

Description

technical field [0001] The invention relates to an intelligent permanent magnet contactor with reverse magnetic field weakening control without a position sensor, which realizes the intelligent dynamic control of the closing process of the permanent magnet contactor, and belongs to the technical field of intelligent low-voltage electrical appliances. Background technique [0002] As a new type of switchgear based on new principles and permanent magnet application technology, the permanent magnet contactor not only realizes all the functions of the electromagnetic contactor, but also has significant energy saving, no noise, is not affected by grid voltage fluctuations, and the coil is not easy to burn out , anti-shaking performance and high reliability, etc., has become a research hotspot in the field of electrical appliances. [0003] In recent years, research on permanent magnet contactors has mostly focused on new permanent magnet operating mechanisms, analog and electroni...

AI Technical Summary

Problems solved by technology

This method has the following disadvantages: first, the price of the displacement or speed sensor is relatively high, which will greatly increase the cost; secondly, the internal space of the contactor is an environment with large noise, strong vibration and even high temperature, and the existing ones on the market Various sensors are often not enough to withstand hundreds of thousands or even millions of reciprocating actions; again, the size of the displacement or speed sensor is relatively large, which obviously increases the volume of the contactor

Small-sized contactors cannot be installed, and the versatility is not strong. At the same time, the increase in the number of movable components will not only increase the failure rate, but also have a certain impact on the dynamic characteristics of the contactor itself.

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