Research On Key Technology Of The ZNZ8-12 Indoor Intelligent Vacuum Circuit Breaker

Intelligent vacuum circuit breakers adopt sensing technology,microcomputer protection technology and state monitoring technology to realize its characteristics of digital measurement,function integration and information interaction.With the construction of distribution internet of things,it is urgent to improve the intelligent level of distribution switch equipment which is not high,it cannot meet the demand of distribution automation.Therefore,it is urgently needed to carry out intelligent design and development of 12kV indoor vacuum circuit breakers with the largest consumption of distribution network,which is of pioneering significance for the development of intelligent equipment of distribution network in the future.Based on the basic theoretical knowledge of 12kV indoor vacuum circuit breaker design,this paper conducts research on the integration of electronic transformer,microcomputer integrated protection device,current sensor of dividing and closing coil with vacuum circuit breaker.The key technical studies of this paper are as follows:First of all,the intelligent of transformer and vacuum circuit breaker is the key to realize the intelligence of vacuum circuit breaker.Aiming at the transformer configuration problem of the existing intelligent circuit breaker,we choose the low power current transformer and electronic voltage transformer to integrate with the vacuum interrupter to form the integrated enclosed column.Analyzed the electric field distribution of the integrated enclosed column,and made the conclusion of the good insulation.By analyzing the magnetic field distribution of the CT coil during the breaking process,it is concluded that the coil has little effect on the breaking performance of the arc extinguishing chamber.It realized the measurement digitization of vacuum circuit breaker in this link.Then,integration of comprehensive protection device and vacuum circuit breaker is another feature of intelligent vacuum circuit breaker.The structure and function of the existing comprehensive protection device are designed for applicability;In particular,the 12kV vacuum circuit breaker is equipped with a circuit breaker opening and closing coil and the current monitoring sensor of the energy storage motor,and the on-line monitoring function is integrated into the comprehensive protection device.Designed the integrated scheme of comprehensive protection device and vacuum circuit breaker,and optimize the grounding position of secondary signal line and mutual inductor in circuit breaker.This method realized the state visualization and function integration of vacuum circuit breaker.Finally,the experimental research after the prototype development is a necessary link to verify the reasonable intelligent vacuum circuit breaker design.As a brand new product,we combined the type test of enclosed column,all insurance device,transformer and circuit breaker model to explore its technical capabilities,we proposed the joint debugging test creatively,which verified the coordination and reliability of the primary and secondary.Eventually,ZNZ8-12 indoor intelligent vacuum circuit breaker was successfully developed.