一种无变频器式舰船交流电力推进系统控制策略研究

Research on Control Strategy of an AC Electric Propulsion System with No Converters

为提高交流电力推进系统功率密度、降低成本,提出一种基于永磁推进电机的无变频器式交流电力推进系统。该系统取消了大功率变频器和减速齿轮箱,原动机与电励磁发电机直连,发电机与推进电机直连。通过控制原动机转速和发电机励磁电流实现对推进电机转速和系统运行状态的调节。建立了该电力推进系统的静态数学模型,提出了系统静态稳定性约束条件,推导了系统主要电气量与发电机励磁电流及负载转矩间的函数关系。为提高系统稳定裕度、提高推进效率及电机容量利用率,分别提出采用δ1+δ2=π/4、Isd2=0和cosθ=1三种控制策略,针对各控制策略和不同的电机参数匹配条件,推导了系统主要电气量与负载转矩间的函数关系。针对系统静态稳定性及各控制策略下系统运行特性开展了数字仿真研究,仿真结果验证了理论分析结果的准确性。

In order to improve the power density of electric propulsion system and reduce the cost, an AC electric propulsion system with permanent magnet propulsion motor and without converters is proposed. In this system, prime mover and electric excitation generator are connected directly, and so are generator and propulsion motor. Adjustment of speed of propulsion motor and status of the system is carried out by governing the speed of prime mover and exitation current of generator. Steady-state mathematical model is constructed and functional relationships between major electrical variables with load torque and field current are deduced. To improve stabability, increase propelling efficiency and system power factor, strategies of ~l＋~2= zc/4, Isd2=O and cosO=l are proposed respectively. Functional relationships between electrical variables and load torque under each control strategies and different parameters matching conditions are researched. Validity and precision of mathematical model and theoretical analysis are verified by mathematical simulation.