Engineering methodology for calculating parameters of the braking resistor in a propulsion electric drive

This article presents an engineering method developed by the authors for calculating the parameters of a braking resistor for a marine electric drive. The method does not require the use of complex multi-loop mathematical models, yet it takes into account the family of reversible mechanical characteristics of the propulsion motor, which enables the determination of the average power dissipated in the braking resistor block during generator operation. The methodology includes the calculation of the braking resistor's resistance and current, taking into consideration the DClink voltage of the frequency converter and the transistor pulse duty cycle. To automate the calculations, the authors developed a mathematical model in MATLAB Simulink. This model allows users to define parameters of the reverse operating mode, adjust the braking time, visualize the power and energy dissipation processes, and quickly obtain the calculated electrical parameters necessary for drafting accurate technical specifications for the braking resistor supplier. The method provides a fast and reasonably accurate estimation of braking resistor parameters, significantly reducing engineering labor. It should be noted that this methodology does not address heat transfer processes or structural aspects of the braking resistor, as these are handled by specialized manufacturers of marine braking resistors.