Three-phase unbalanced commutation molded case circuit breaker

Abstract

A three-phase unbalanced phase-change molded case circuit breaker comprises a circuit breaker body, a contact module, a transmission mechanism, an arc extinguish chamber and a phase-change switch, the contact module comprises a static contact and a moving contact, the static contact is located in the arc extinguish chamber, the static contact is connected with a first wiring board, and the moving contact is connected with a second wiring board; the second wiring board is connected to the input end of the phase-change switch; the transmission mechanism comprises a pull rod, a connecting plate and a rotating support, the moving contact is located at one end of the rotating support, one end of the pull rod is located at the other end of the rotating support, the other end of the pull rod is connected with the connecting plate, and the connecting plate is matched with a permanent magnet fixed to the circuit breaker body.

Description

technical field [0001] The invention relates to a three-phase unbalanced commutation molded case circuit breaker. Background technique [0002] Molded case circuit breakers can automatically cut off the current after the current exceeds the trip setting. Plastic case refers to the use of plastic insulators as the outer casing of the device to isolate the conductors and ground metal parts. Molded case circuit breakers typically contain a thermal-magnetic trip unit, while larger molded case circuit breakers are equipped with solid-state trip sensors. The trip unit is divided into: thermal magnetic trip and electronic trip. [0003] Molded case circuit breakers are also known as device circuit breakers. All parts are sealed in a plastic case. Auxiliary contacts, undervoltage releases and shunt releases are mostly modular. Due to its very compact structure, molded case circuit breakers are basically impossible to overhaul. Most of them use manual operation, and large-capacit...

AI Technical Summary

Problems solved by technology

There are a large number of single-phase loads in the low-voltage distribution area, and the power consumption time of these single-phase loads is very random, resulting in a serious unbalance of the three-phase load in the low-voltage distribution area, increasing the loss of the transformer, and causing The internal temperature of the transformer rises, which will cause damage to the transformer and reduce the quality of power supply in severe cases

In addition, the power grid has been in a three-phase unbalanced state for a long time, which will also have a negative impact on the electrical equipment in the low-voltage station area. In the face of the unbalanced three-phase load of the line caused by the complex site environment, the current treatment method requires the installation of reactive power compensation devices. There are problems such as high cost, low efficiency, large volume, single function, difficult implementation, and non-real-time performance when installing phase change switches and other equipment.

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