Design And Study On The Characteristics Of The Novel High Speed Electromagnet With Permanent Magnet

High speed solenoid valve is the key component of electronic control fuel injection system for marine diesel engines,whose dynamic response speed directly determines the precision of injection,even affect the performance of the marine diesel engine.In order to meet the increasingly strict exhaust emission regulation and improve the economy of the fuel injection,improve the dynamic response speed of high speed solenoid valve of diesel engine is necessary.In this paper,a novel high speed electromagnet with permanent magnet is proposed based on the research of the conventional E type electromagnet.The influence of permanent magnet on the static and transient characteristics of high speed solenoid valve is studied,It lays a theoretical foundation for improving the working characteristics of the high speed solenoid valve and the consistency of the fuel injection law of the diesel engine.First,working principle of high speed electromagnet is analyzed,at the same time,magnetic circuit method and empirical formula are used to calculate the initial dimension parameters.The static and transient finite element model of the electromagnet is established according to the initial design results in Ansys Maxwell.The static finite element model was calibrated by the experimental results.It turns out that the static finite element simulation model's maximum error is 7%,the accuracy of the model is verified,and it can meet the needs the requirements,so the numerical simulation model can be used to calculate accurate electromagnetic force.The static electromagnetic force characteristics of a novel high speed electromagnet with permanent magnet are analyzed by the static finite element model.Its electromagnetic force has been greatly improved,compared with the conventional E type electromagnet.Then,the coupling flux?conversion coefficient and the working point of permanent magnet are studied.Finally,the influence of permanent magnet width,height,spring preload,coil turns and residual air gap on the dynamic characteristics of electromagnet is studied by using the transient simulation model.At the same time,the five key factors that affect the dynamic response characteristics of the high speed solenoid valve are used as the variables to be optimized,and the sample points are found by the Optimal Latin hypercube experimental design.The Kriging approximate model is built aiming at closing response time,opening response time.And robust optimization mathematical model is constructed based on theKriging approximation model.The Pareto solution is obtained by NSGA-II genetic algorithm.The final solution is determined by distance function,the results show that the approximate model can accurately predict the dynamic response characteristics by comparing the results with the simulation model.By the robust optimization,closing response time and opening response time were reduced,and the fluctuations also decrease.It provides a theoretical support for enhancing the stability of its dynamic performance.