Studies on the performances and control of shaft generation systems

轴发电机系统利用主机产生的部分电力为船舶提供所需的电力。本文首先推导了一组系统方程，以估计输出电压的总谐波畸变为例。阐明了各参数对系统性能的影响以及系统的运行极限。研究表明，当逆变器前导角较大时，系统的工作范围变宽。此外，提出了一种考虑系统损耗的方法，以获得精确的计算结果。然后讨论了系统同步冷凝器的视在功率。并对轴向发电机系统的暂态性能进行了详细分析。推导了系统的暂态方程，计算了直流输入电压上升时系统的暂态响应，并与实验结果进行了比较。研究了系统负荷阶跃变化情况下的瞬态响应。最后，对带感应电机负载的轴向发电机系统进行了暂态性能分析。首先介绍了电机的简单暂态模型。该模型与轴向发电机系统的暂态模型相结合。用该方框图模拟了感应电动机与轴发电机输出端连接时的瞬态响应。将仿真响应与测试系统的实验响应进行了比较，验证了理论的有效性。此外，还研究了轴向发电机系统中同步凝汽器和异步电动机的转动惯量对系统暂态性能的影响。

A shaft generator system supplies electrical power required in a ship by using a part of the power produced by the main engine. In this report, a set of system equations, by which the total harmonic distorition of the output voltage, for example, can be estimated, is derived first. The effects of various parameters on the system performances and the operation limit of the system are then clarified. It has been shown that when the leading angle of the inverter is large, the operating range of the system is widened. Moreover, a way of taking the system losses into account is proposed to obtain precise calculation results. The apparent power for the synchronous condenser of the system is then discussed. Also, transient performance of he shaft generator system is analyzed in detail. A set of transient equations of the system is derived, and the transient responses of the system in the case of a step-up change in the dc input voltage are calculated and compared with experimental ones. Transient responses in the case of step change in the system load are also investigated. Finally, transient performance analysis of the shaft generator system is presented for the case with a load of an induction motor. A simple transient model for the motor is introduced first. This motor model is united with the transient model for the shaft generator system. Transient responses when the induction motor is connected to the output terminals of the shaft generator are simulated with this block diagram. The simulated responses are compared with the experimental responses with the tested system, and the usefulness of the theory is confirmed. Also, the effects of the inertia moments of the synchronous condenser in the shaft generator system and the induction motor on the transient performances of the system are studied.