Numerical calculation of load characteristics of motor direct drive actuator based on Lagrange equation

A numerical calculation method for analyzing the load characteristics of a motor direct drive actuator in high-voltage circuit breakers using the Lagrange equation is presented in this paper. The study focuses on the kinematic and dynamic modeling of the operating mechanism, which includes a transmission system converting motor rotation into linear motion for circuit breaker operation. By selecting joint coordinates as generalized coordinates, the Lagrange equation is employed to derive an analytical solution for the load torque, capturing the system’s dynamic behavior without explicitly calculating complex constraint forces. Simulation and experimental results validate the proposed model, demonstrating its accuracy in predicting torque variations during the opening and closing processes. The findings highlight the effectiveness of the Lagrange equation in simplifying the dynamic analysis of motor direct drive systems, providing a theoretical foundation for control design and optimization.