Reseach On The Hardware-in-the-loop Simulation Platform For Propeller Load Characteristics

In order to study the ship electric propulsion system, Dalian Maritime University is building the laboratory of ship electric propulsion system. A propulsion motor towing a loading motor is adopted to simulate the ship propulsion motor towing the propeller in the laboratory. To make the electric propulsion system matching the ship to the maximum extent, the propulsion motor needs the load that simulating the propeller on the ship to the maximum extent. The working characteristic of a propeller is complicated in the process of ship maneuvering. Moreover, its propulsion characteristics will be seriously affected when the ship encountering with wind, wave and current. Therefore, it is particularly important to control the loading motor to provide the propulsion motor with load that simulating the propeller working characteristics in ship maneuvering for studying the steady and dynamic characteristics of the electric propulsion system.According to the actual requirement of the laboratory of ship electric propulsion system, this paper takes the hardware-in-the-loop simulation platform of propeller load characteristics as the research object, which is divided into software simulation and hardware platform. The software simulation is programmed in the LabVIEW. This paper starts with the four quadrants model of a propeller, then builds the pull podded propulsor model, a double pod driven ship planar motion model and wind, wave and current disturbance model. In the pull podded propulsor model, the propeller and pod body is modeled separately, then take the influence of propeller to the pod body into consideration. In the ship motion model, Woodward formula for pod driven ships is used for the computation of ship hull hydrodynamic coefficients. In the wind force model, the influence of wind velocity profile is counted, and the Fujiwara formula is improved. In the wave force model, the JONS WAP spectrum is used. The influence of current force is taken into ship hull dydrohynamic calculation.The input signals of software simulation program is provided through data acquisition card NI PXIe-6356, which also outputs the control sigals to the frequency converter SINAMICS S120that controlling the loading motor. Load the programmed LabVIEW progarm into the on line simulator NI PXIe-8351, which is running the real-time operating system. Experiments of straight running, turning and zigzag maneuvering are conducted both in calm water and heavy sea conditions. The experimental results show that the established pod driven ship motion model and disturbance model can basically reflect the ship maneuvering, and the loading motor can provide the propulsion motor with load that simulating the ship propeller working characteristics.