Modeling of combined permanent magnet subsection recoil line

The establishment of equivalent circuit modeling of permanent magnet (PM) is the key to the design of PM relays. Failure to consider the external leakage in magnetic flux of PM would generally lead to a lower design precision of relay operation. Based on the proposal idea of a PM subsection model, this paper analyzed the model theoretically and presented the equivalent magnetic circuit model in three typical working conditions (open magnetic circuit, close magnetic circuit, and electromagnetic system). By studying the three magnetic circuit conditions, the solution of calculating the working point of each PM subsection based on the magnetic circuit method had been obtained. Furthermore, it is concluded that each PM subsection works on the different recoil line. The conclusion has been verified by the simulations and experiments.