Research On Harmonic Suppression Of Ship Power System

With the rise of the shipbuilding industry,electronic and electronic equipment has been used in large quantities,which has brought endless harmonic pollution problems.Under the premise of understanding the harmonic problem of the ship's power grid,the existing harmonic control methods are understood and summarized.Mainly for the harmonic detection and tracking control two more intensive research.This paper first discusses the necessity of harmonic management of ship power grid,and then describes the research status and development trend of active filter,harmonic detection and current tracking control in detail,and then elaborates the harmonic problem of ship power grid.Including the hazards caused by harmonics on the ship's power grid system,the main harmonic sources of the ship's power system are analyzed,and the hazards of the harmonics on the ship's power system are quantitatively analyzed,which points the direction for the later harmonic control.Finally,using a large number of calculation formulas allows us to understand the basic concepts of harmonics more clearly.In addition,the standards for harmonic control at home and abroad are listed,and these standards are similar.The basic concept of harmonics and its governance standards paved the way for subsequent harmonic control.The active filter is then analyzed in detail.The classification of active power filters is first introduced.Then,the circuit structure and principle of active filtering are briefly explained.In order to gain a deep understanding of the active filter.A mathematical model has been established for analysis,but there are limitations due to the analysis in this coordinate system.It also transforms its coordinates for better analysis and control.Then,in the aspect of harmonic detection,the RBF neural network is highlighted,and the harmonic detection of the RBF neural network is improved to some extent.Finally,the principle and characteristics of PI control and repetitive control are briefly explained.Then the design of the composite controller is described in detail,and the corresponding mathematical model is constructed.This kind of control can not only reduce the harmonic content,but also maintain the characteristics of PI control,but there are also some problems.Therefore,in this paper,a modified repeat controller and a PI regulator are used together to control the method.Through simulation comparison,it is found that the two situations are analyzed when the load suddenly changes or the load is in normal operation.The optimized neural networkcan improve the detection accuracy of harmonic current and the response speed of harmonic detection more quickly.With the improved repetitive control method,the error in the steady operation state is smaller,and the gain range that can be self-regulated is larger,and the control period of the improved control method is also reduced by about half compared with the previous one.