Research on torsional vibration monitoring system of ship power shafting

In this paper, the real-time monitoring technology of ship power system torsional vibration is studied. The photoelectric non-contact measurement method is used to measure the torsional vibration intensity of shafting, and the analysis service network management platform is established to realize the functions of real-time monitoring of shafting torsional vibration and upload and collect alarm data, through the front-end system, the torsional vibration strength and other parameters of the shafting are collected and transmitted to the background. The data of the background system is used to calculate and analyze, and the status of the shafting is alarmed. The system realizes continuous monitoring and data recording of torsional vibration index of ship power system, and ensures the operation performance and safe operation of ship power system. It provides theoretical and technical support for the future development of new technologies and related research, such as durability simulation and durability virtual test of ship power critical parts.

A fractional-order ship power system: chaos and its dynamical properties

In this research, the ship power system is studied with a fractional-order approach. A 2-D model of a two-generator parallel-connected is considered. A chaotic attractor is observed for particular parameter values. The fractional-order form is calculated with the Adam–Bashforth–Moulton method. The chaotic response is identified even for the order 0.99. Phase portrait is generated using the Caputo derivative approach. Wolf’s algorithm is used to calculate Lyapunov exponents. For the considered values of parameters, one positive Lyapunov exponent confirms the existence of chaos. Bifurcation diagrams are presented to analyze the various dynamical behaviors and bifurcation points. Interestingly, the considered system is multistable. Also, antimonotonicity, period-doubling, and period halving are observed in the bifurcation diagram. As the last step, a fractional-order controller is designed to remove chaotic dynamics. Time plots are simulated to show the effectiveness of the controller.

Sensitivity Analysis of Optimal Power Dispatch for All-Electric Ship

Shipping industry is reforming and changing fast, as the International Maritime Organization (IMO) works towards air pollution prevention and ship-owners pursue more efficient operation of their ships. Formerly, propulsion and electric load dispatch in ship power system is implemented proportionally with respect to nominal power of prime movers and generators respectively. Additionally, integrated full electric propulsion, optimal real-time dispatch to ship generators and the integration of new systems, such as energy storage systems, shaft generators etc. could have gained a wider application. In this paper the optimal dispatch for ship power system based on Lagrange method is presented comparing the classic and all-electric ship design. The developed method is applied to an ten years old Ro-Ro (roll on / roll off) passenger ship and an analytical sensitivity analysis is occurred out with respect not only to technical characteristics of the ship, such as fuel kind, propulsion chain factors, but also voyage characteristics, such as ship speed, route length etc.