SYSTEM DYNAMIC SIMULATING MODELLING OF DRIVING SYSTEM “ANCHOR WINDLASS DRIVEN BY ASYNCHRONOUS MOTOR” ( BSVPAM ) ANTE MUNITIĆ, MARIO ORŠULIĆ, MAJA KRČUM, JOŠKO DVORNIK Split College of Maritime Studies University of Split Zrinsko-frankopanska 38, 21000 Split, Croatia e-mail: munitic@pfst.hr Abstract System dynamic simulating modelling is one of the most appropriate and successful scientific dynamics modelling methods of the complex, non- linear i.e. natural, technical and organisational systems. Investigation of behaviour dynamics of the ship’s propulsion system as a typical example of complex, dynamic technical systems requires application of the most efficient modelling methods. The aim of this essay is to present the efficiency of application of the system-dynamic simulating modelling in investigation of behaviour dynamics of the BSVPAM propulsion system. The anchor windlass and its driving asynchronous motor shall be presented by mental - verbal, structural and mathematical computing models. The System Dynamics Models are, in essence, continuous models because the realities are presented by the set of non-linear differential equations, i.e.” equations of state”. They are at the same time discrete models, because they used basic time step for counting i.e. discrete sampling DT, which value is determined in total accordance with “SAMPLING THEOREM” (Shannon and Koteljnikov). With the choice of basic time step DT it is possible to do computer modelling of continuous simulation models on digital computer, which is very suitable for education of the marine students and engineers, because they can study complex dynamics behaviour of marine systems and process. Keywords System Dynamics, Modelling, Asynchronous Engine, Windlass, Continuous and Discrete Simulation 1. INTRODUCTION The System Dynamics Modelling is in essence special, i.e. “holistic” approach to the simulation of the dynamics behaviour of natural, technical and organisation systems, and it contains quantitative and qualitative Simulation Modelling of various natured realities. The concept of optimisation in System Dynamics is based on belief that the manual and iterative procedure, i.e. optimisation by the method “retry and error” can be successfully executed using heuristic optimisation algorithm, with the help of digital computer, and in complete coordination with System Dynamics Simulation Methodology. This simulation model BSVPAM is small part of scientifically macro project called: Intelligent Computer Simulation of the Model of Marine Processes. 2. SYSTEM- DYNAMIC SIMULATING SYSTEM MODELS “ANCHOR WINDLASS DRIVEN BY ASYNCHRONOUS MOTOR” 2.1. System dynamic model of the anchor windlass Anchoring is an operation by which the ship is fixed to the ship’s bottom. This is performed by the anchor arrangement consisting of: anchor, anchor chains, stoppers, chain locker and windlass. Some elements of the anchor arrangement are also used for the mooring of a ship. All ships are provided with the bow anchor arrangement and some of them with the stern anchor arrangement. Ships of less size may be provided with anchor windlasses driven by the internal combustion engines while on tankers where such drive may cause explosion windlasses are driven by steam. Windlasses on other ships are mostly driven by electric motors and recently are also hydraulically driven. Electric drive of windlasses shall be performed by: - the alternative three phase electric motor, in Leonard’s connection, alternative three phase electric motor directly coupled with overlapping of two or three pairs of pole. Anchor windlass consists of driving electric motor with stopper, reduction gear and main shaft unit laid