舰船谐波引起次同步震荡的研究

现代舰船已经广泛使有电力推进系统，随着舰船的体积变大，负荷也随之变大，装备的现代化，其微电网系统也越来越复杂。所以对微电网的稳定的要求也越来越高。本文先介绍了舰船电力系统结构是多电机结构，是交流负载和直流负载的混合系统，所以舰船微电网的谐波问题严重。而谐波等不稳定因素可以导致微电网系统次同步震荡。然后文章介绍了次同步震荡的机理，从原理出发，创新的建立了燃气轮机的五轴模型，利用PSCAD进行仿真。通过实际仿真，发现发电机很容易发生轴系扭振。应该避免这一情况。文章从分析常用的方法入手，分析了常用方法的利和弊，然后还是从原理出发，用串联电容消除部分谐波，对线路进行补偿。用这种可靠的方式来消除和减少次同步震荡，最后用仿真进行验证，论证了方法可行。

Study on Sub-synchronous Vibration of Ship Harmonics

Modern ships have been widely equipped with electric propulsion system. With the ships becoming larger, the load also being larger and more modern equipments, the micro-grid system is also more complex. Therefore, the stability of the micro-grid requirements is increasing. This article firstly describes that the structure of marine power system is a multi-motor structure which is the hybrid system of the AC load and DC load, so the ship micro-grid harmonic problem is serious. The harmonics and other instability reasons can cause sub-synchronous oscillation in the micro-grid system. Then the article describes the mechanism of sub-synchronous oscillations, and, starting from the principle, innovatively establishes a gas turbine five-axis model under the PSCAD simulation. Through the simulation, it can be found that generators are prone to torsion vibration. To avoid this situation, the article analyzes the advantages and disadvantages of the common methods. Serial capacitors are used to eliminate some harmonics and to compensate the line. By taking this reliable way to eliminate and reduce sub-synchronous oscillation, it is finally verified on simulation and demonstrated feasible. Keywords: Micro-grid, Sub-synchronous Oscillation, Electric Propulsion, Harmonics