Abstract: To make the performance characteristics of bimetallic strip products more stable,a mathematical model of the output characteristic value y of the bimetallic product was established considering various factors and taking the sum of the idle stroke margin under the stable current of the product and the stroke margin under the operating current as the design margin; the parameter design method is used to analyze the influencing factors in the mathematical model of the operating characteristics of the bimetallic product.The results show that:the larger the main double-specific bending value,the smaller the auxiliary double-specific bending value,the smaller the out-of-synchronization error generated after verification,the better the output of the operating characteristics.The mathematical model of the operating characteristics value y can provide an effective direction and basis for the design optimization and process improvement of the stability of operating characteristics of the motor starter.

Key words: bimetallic, performance characteristics, design margin, parametric design