Application of dynamic braking in frequency-controlled drives of ship machinery

Object and purpose of research. This paper studies automated frequency-controlled electric drive of a ship mechanism (thruster) in the electric propulsion system of various advanced ships. The purpose of this work is to develop a flow chart of frequency-controlled electric drive of ship mechanism (a thruster, as an example) that would feature, instead of currently used generator-based braking, the dynamic braking that offers significant gains in weight and size of the whole drive. Materials and methods. Scientific and technical information, as well as personal findings and experience of the authors, gathered over the years of various R&D projects in electric drives for various ship machinery. The solution to the challenge discussed in this paper is based on the method of developing a frequency-controlled electric drive, where static converter can convert the system of three-phase voltage with constant parameters into the one with smoothly-adjustable parameters, as well as to convert the said system into the system of constant, smoothly-adjustable voltage. Main results. The authors have developed a flow chart of frequency-controlled electric drive for ship mechanism (thruster) with dynamic braking, as well as enumerated other ship machinery items where electric drives are also practicable to feature this system. Their results are confirmed by simulations of electromechanical processes taking place in given electric drive of ship thruster. The diagrams of these processes, as well as their analysis, are also given in this paper. Conclusion. These solutions can be implemented in development of electric drives for machinery of advanced ships.