【作者】 王琦；

【导师】 林治国；

【作者基本信息】 武汉理工大学 ， 轮机工程， 2020， 硕士

【摘要】 综合电力系统是船舶的发展方向之一,直流综合电力系统相较于交流综合电力系统具有发电机并网简单、燃油消耗低、便于接入新能源系统等优势,将成为下一阶段智能船舶的发展方向。本文以直流组网电力系统船舶——镇扬汽渡3011轮为研究对象,基于Matlab/Simulink软件平台搭建系统仿真模型,来研究变速柴油机转速控制、异步发电机整流及母线电压稳压控制、超级电容控制和综合电力系统能量管理策略等问题。具体研究内容如下:首先对直流组网电力系统核心设备——变速柴油发电机的控制进行研究。针对柴油机转速控制问题,分析了数学模型转速寻优和基于万有特性曲线转速寻优两种方法,在此基础上设计了无级调速控制策略和分级调速控制策略;针对异步发电机整流及恒压控制问题,提出采用非线性补偿方法,通过设计解耦控制器,实现转子磁场定向控制,同时设计电压外环控制和磁化电流外环控制来实现母线电压稳定,并通过仿真实验验证了控制策略的有效性。然后,对船舶直流组网电力系统控制策略进行研究。阐述直流电网下垂控制原理,分析了传统下垂控制的局限性,针对母线电压降落的问题,提出一种带电压补偿的改进型直流母线下垂控制方法;针对系统负载功率突变柴油机不能及时响应的问题,发挥超级电容储能装置快速充放电优势,来补偿直流母线能量变化,减少直流母线电压波动。最后,针对柴油发电机组和超级电容电力系统,结合实际航行工况,提出基于滤波器分流的能量管理策略。该策略使用置信规则库方法识别船舶工况,在定速航行工况,控制柴油机工作在最佳工况点,超级电容对系统功率变化进行补偿;在机动航行工况,设计低通滤波器对功率分解,控制柴油发电机组承担功率变化低频部分,超级电容承担功率变化高频部分,避免柴油发电机组输出功率剧烈变化,从而优化柴油机工况,在一定程度上可以节约燃油消耗,改善排放品质。更多还原

【Abstract】 Integrated power system is one of development direction of ship.Compared with AC networking system,there are several outstanding advantages of DC networking system including simple generator connection,low fuel consumption,easy access to the new energy system,it will become the development direction of intelligent ships.In this paper,a DC-connected power system ship,"Zhenyang ferry 3011",was used as the research object,and a system simulation model was built based on the "Matlab/Simulink" platform to analysis the speed control of variable-speed diesel,asynchronous generator ‘ s rectification,and bus voltage stabilization control,supercapacitor control and integrated power system’s energy management strategies.The specific research contents are as follows:Firstly,make an analysis about the control of the core equipment of the DC gridconnected power system and the variable speed diesel generator.In view of the speed control problem,two methods of speed optimization of the mathematical model and speed optimization based on the universal characteristic curve were analyzed,on this basis,a stepless speed control strategy and a stepped speed control strategy were designed.For the problems of asynchronous generator rectification and constant voltage control,a non-linear compensation method was proposed,the decoupling controller was designed to realize the rotor field-oriented control,and the voltage outer loop control and magnetization were also designed.Current outer loop control was used to achieve bus voltage stabilization,and the effectiveness of the control strategy was verified by simulation experiments.Secondly,research on the control strategy of the ship’s DC power system,the principle of droop control in DC power grid was introduced,the limitations of traditional droop control were analyzed,and an improved DC bus droop control method based on voltage compensation was proposed for the problem of bus voltage drop.Aiming at the problem that the diesel engine with transient load can not respond in time,the advantages of the rapid charge and discharge of the supercapacitor energy storage device are used to compensate the DC bus energy change and reduce the DC bus voltage fluctuation.Finally,a hybrid power system based on diesel generators and supercapacitors was combined with the actual navigation conditions to propose an energy management strategy based on filter shunting.The strategy used the Belief rule base method to identify the ship’s operating conditions.In fixed-speed navigation conditions,diesel work at the optimal operating point,supercapacitors compensate for system power changes.In maneuvering conditions,low-pass filters are designed.Regarding the power decomposition,the diesel generators were controlled to bear the low-frequency part of the power,and the supercapacitors were assumed to bear the high-frequency power to avoid drastic changes in the output power of the diesel generators,thereby optimizing the operating conditions of the diesel engine,which can save fuel consumption and improve emission quality to a certain extent.更多还原