Applications of doubly-fed machine in simulating load of marine electric propulsion

The developments of electric propulsion technique need high power propulsion motor testing system, in which propeller load simulation is an important part. In this paper, a new doubly-fed machine load system is presented to simulate the stable and dynamical properties of marine propeller operating in different conditions. By changing the magnitude and phase of the rotor voltage, the input torque of the doubly-fed machine can be adjusted, furthermore, it can generate power in the mode of variable velocity-consistent frequency, and then the energy can feed back to the power network. Under the vector control strategy of stator field-orient, a vector control model is founded by using the software of Matlab/Simulink. The results show that the doubly-fed machine can simulate the propeller torque features perfectly in four quadrants