Research On MCCB Terminal Heating And On-line Monitor System Of Terminal Temperature Rise

Mould case circuit breaker (MCCB) is an usual low-voltage equipment using in low-voltage power distribution system. On-line monitoring of varied parameters and remote control of MCCB are orientation of development in low-voltage devices in the future.In varied parameters, temperature rise on MCCB terminal is an important parameter. Terminal is a vital part which connects MCCB and power line. Abnormal temperature rise will not only produce hidden trouble in mechanical part, leading to accident in low-voltage power distribution network, but also cause electrical fire in buildings. Meanwhile, the heat generation per unit volume has increased because the size of MCCB has decreased. Accordingly, heating on terminal is a problem which could not be neglected due to miniaturization of MCCB.Researches on temperature rise of MCCB terminal are made in this paper. Analyses of communication technology and temperature rise are given. By using LonWorks power line communication techniques, data collection and communication module for parameters of MCCB terminal is developed, main point in the process of designing is presented. Monitoring software is designed base on Visual Basic and Access database. Hardware and software designed are established to experimental platform of data collection of MCCB terminal.This paper gives analysis on the characters of MCCB terminals, putting forward of MCCB heating model based on thermal network method. From data obtained in experiments, factors which affect terminal heating are analyzed. Temperature rise curves are fitted by using least-square method and time constant is deduced. Method of efficient calculation on MCCB terminal temperature rise is discussed.