虚拟同步机逆变器的实现及特性测试方法的研究

发布时间：2018-06-03 17:27

本文选题：虚拟同步发电机 + 下垂控制　；参考：《华北电力大学》2017年硕士论文

【摘要】：微电网是未来智能配电网系统的一种重要组网模式,其运行控制系统是确保微电网安全、稳定、可靠运行的关键。微源接口的并网单元动态响应速度快,几乎没有惯性,在配电网出现扰动或电能供需不平衡时,无法像传统同步发电机那样,利用储存在转子上的动能来抑制功率或者频率的波动。同时,传统方式下利用DSP开发系统,设计者不仅要开发控制算法,而且要花大量时间去掌握DSP内部的各种寄存器的正确设置及软件编译方法,代码的编写、调试会耗费大量的时间和精力。因此,本文采用一种基于实时代码生成工具Real Time Workshop(RTW)的虚拟同步发电机逆变器实现的方法。本文的主要研究内容如下:首先,对微源主电路拓扑结构进行了阐述,并对双环控制方法进行了分析和研究,包括内环控制方法和外环控制方法。其次,对虚拟同步发电机进行了建模。将同步发电机的定子电压方程和转子运动方程引入到微源的控制中,分析了电力系统中同步发电机的功频特性和励磁特性,设计了虚拟同步发电机的功频控制器和励磁控制器。通过下垂控制策略和虚拟同步发电机控制策略的仿真对比,得出转动惯量和阻尼系数对频率的突变有抑制作用。对虚拟同步发电机控制中的关键参数进行了仿真分析,分别得出转动惯量和阻尼系数对于微电网系统频率的影响。最后,提出一种基于实时代码生成工具的虚拟同步发电机逆变器实现的方法。给出了基于RTW实现虚拟同步发电机的设计流程,搭建微源逆变器平台,对硬件电路和软件设计进行详细的介绍。通过和下垂控制策略的实验对比,验证了虚拟同步发电机控制策略的控制特性。
[Abstract]:Microgrid is an important networking mode of smart distribution network system in the future. Its operation control system is the key to ensure the safe, stable and reliable operation of microgrid. The dynamic response of the grid-connected unit with micro-source interface is fast and has almost no inertia. When the distribution network is disturbed or the power supply and demand is unbalanced, it can not be like the traditional synchronous generator. Use the kinetic energy stored on the rotor to suppress fluctuations in power or frequency. At the same time, using DSP to develop system in traditional way, the designer should not only develop control algorithm, but also spend a lot of time to master the correct setting of various registers in DSP, the method of compiling software and the writing of code. Debugging can take a lot of time and effort. Therefore, a virtual synchronous generator inverter based on real-time code generation tool Real Time Workshop / RTW is proposed in this paper. The main contents of this paper are as follows: firstly, the topology of the microsource main circuit is described, and the double loop control method is analyzed and studied, including the inner loop control method and the outer loop control method. Secondly, the virtual synchronous generator is modeled. The stator voltage equation and rotor motion equation of synchronous generator are introduced into the control of micro-source. The power-frequency and excitation characteristics of synchronous generator in power system are analyzed, and the power-frequency controller and excitation controller of virtual synchronous generator are designed. By comparing the droop control strategy with the virtual synchronous generator control strategy, it is concluded that the moment of inertia and damping coefficient can restrain the frequency mutation. The key parameters in the control of virtual synchronous generator are simulated and analyzed. The influence of inertia and damping coefficient on the frequency of microgrid system is obtained. Finally, a realization method of virtual synchronous generator inverter based on real-time code generation tool is proposed. The design flow of virtual synchronous generator based on RTW is given, the platform of micro-source inverter is built, and the hardware circuit and software design are introduced in detail. Compared with the droop control strategy, the control characteristics of the virtual synchronous generator are verified.
【学位授予单位】：华北电力大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM464

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