Modeling of 3/12-phase Generator Using Implicit Trapezoidal & Time-step-holding Method

The integrated power system(IPS) contains special,high-order and non-linear components like 3/12-phase double winding generators.These components' simulation models are not offered by any power system electromagnetic transient simulation software.To model the double winding generators,the implicit trapezoidal method was applied to transfer the double winding generator's mathematical model into difference equations.By using the stator-rotor-separate iteration method,the generator's equivalent circuit model was derived.Then,the simulation model of double winding generators was built in PSCAD.During the modeling,the time-step-holding method was introduced to divide the model's simulation steps into computation steps and holding steps.In this way,the calculating speed was increased.Finally,the test bed of integrated electric propulsion system was constructed.The experiments on no-load short-circuit of the generator and on the speeding of the propulsion system were carried out and the same events were then simulated.The comparison between experimental and simulative results shows the availability of the modeling method and the correctness of the 3/12-phase double winding generator model.The study shows that the modeling method introduced in this paper can be used to build the simulation model of double winding generators accurately and efficiently.It can be applied to other EMTP-kind simulation software,and can be used for modeling of other multi-phase machines in IPS.