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Abstract. Regarding straightening unit as the research object, considered the different of roller spacing, a mathematical model of intermesh schedule suitable to the 2800 seven-roller strong heavy plate straightening machine was deduced by the geometric method. According to the mathematical model, the intermesh schedules of several specifications of plate were calculated, and the finite element model of straightening process was established in the finite element analysis software Abaqus. By analysing, it was found that those plates after straightening cannot meet the requirement of flatness, due to the existence of the work hardening. The bending deflection of the last straightening unit was modified and the new calculation formula of intermesh schedule was obtained. The values of the modified coefficients were determined by the finite element method. The intermesh schedules of other specifications of plate were calculated by the modified calculation formula and then verified it in Abaqus. The simulation results showed that those plates after straightening meet the requirement of flatness. So, the research results provide a theoretical basis for development of a new plate straightening machine and formulation of intermesh schedule. General instructionsAt present , the straightening intermesh schedule of strip and medium thin plate is studied more [1], but the heavy plate more than 50mm is usually straightened by the less efficient pressure straightening machine. And the algorithm of intermesh schedule for some thick plate roller straightening machine ignore the different of roller spacing, and it is inaccuracy. To obtain the straightening intermesh schedule meeting the requirements the repeated adjusting with experience is needed [2].In order to improve the speed of formulating intermesh schedule and the straightening work efficiency , for the 2800 seven-roller strong heavy plate straightening machine designed by Yanshan University, a mathematical model of intermesh schedule is deduced. Introduced modified coefficient X ,through the simulation of the finite element software Abaqus, the effect of plate thickness and yield strength on straightening result is studied, and the value curves of thickness effect coefficient and strength effect coefficient are fitted , then the value of modified coefficient X is determined and verified by the finite element method (FEM) . The modified calculation formula Improve the accuracy of formulate intermesh schedule and reduce the number of adjustment.

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High-voltage vacuum circuit breakers are intended for breaking the short-circuit current, and the breaking capacity is the major performance indicator. In the paper， the Weil synthetic circuit was built, and by using unit testing method and referring to standard GB/T 1984GB/T -2014, the breaking capacity of 126kV/2500A/40kA double-break vacuum circuit breaker developed by Central Research Institute of Tianjin Benefo Machinery Equipment Group Co., LTD was tested. Result showed that this vacuum circuit break can meet the breaking capacity requirement for grid integration