基于大功率电力电子技术可靠供电系统

发布时间：2018-04-02 21:20

本文选题：电力系统可靠性　切入点：供电可靠性　出处：《华中科技大学》2014年博士论文

【摘要】：更高的电力系统可靠性是电力供应商追求的目标,也是电力用户的客观要求。电网规模越来越大,越来越复杂,特别是工业敏感负荷比重越来越大,以及含有分布式电源的微网大量接入电网等情况,给电力系统可靠性提出了挑战。随着电力电子技术的发展,电力电子装置容量也越来越大,技术越来越成熟,因此在电力系统中得到越来越广泛的应用,为提高电力系统可靠性提供了有效技术途径。本文研究的主要内容即为采用大功率电力电子技术提高电力系统供电可靠性,包括以下几个方面：首先研究了一种基于储能和柴油发电机的可靠供电系统,详细分析了系统各个部分数学模型及控制策略,研究了系统工作原理、工作状态转换、切换控制策略、储能柴油机协调控制等内容。仿真表明系统在各工作状态及状态切换过程中控制性能良好,可有效提高工业敏感负荷的供电可靠性。然后研究了中低压转换开关系统,转换开关是大型工业敏感负荷双电源或多电源供电系统中的重要部分。文中介绍了一种400V/1000kVA混合式自动转换开关工作原理及切换控制策略,并通过现场实验和试运行验证了各种切换控制策略的正确性,文中研制的混合式转换开关大大缩短了先前机械开关的转换时间,有效提高了应用现场敏感负荷的供电可靠性。文中还研究了10kV静态转换开关带变压器负荷切换过程产生涌流的问题,分析了涌流产生的原因,并提出了一种消除涌流的切换控制策略,仿真和实验都证明提出的策略能够有效消除涌流,避免切换失败,从而在0kV配网一级提高了供电可靠性。随后研究了微网供电可靠性相关问题,主要研究了微网中储能及变换器并网/离网切换控制策略,提出了一种基于滞环电流控制的加速离网切换方法,有效缩短了切换导致的电压跌落时间,仿真和实验都验证了该切换方法的有效性,能够有效提高微网中敏感负荷的供电可靠性。文中还分析了微网中分布式电源发生故障的特性,并提出了一种基于功率变化量的微网保护策略,仿真表明该策略能够将微网中的故障隔离在最小区域,有助于提高微网供电可靠性指标。最后,本文研究了储能型VSC励磁系统提高发电系统动态可靠性,建立了储能型VSC励磁控制的单机无穷大线性化模型,并提出了基于相位补偿的有功无功注入控制方法,对比分析了多种阻尼措施的利弊和阻尼效果。仿真表明储能型VSC励磁系统能够提供比传统晶闸管励磁及无储能VSC励磁更大的阻尼,能够有效提高电力系统小扰动和大扰动功角稳定性。文中还对非储能型VSC励磁系统建立了实验平台,并进行了初步验证性实验,为后续工业样机研制奠定了基础。
[Abstract]:Higher reliability of power system is the goal of power suppliers and also the objective requirement of power users.The increasing scale and complexity of the power network, especially the increasing proportion of industrial sensitive load, and the large number of microgrids with distributed power supply, have challenged the reliability of power system.With the development of power electronics technology, the capacity of power electronic devices is becoming larger and larger, and the technology is more and more mature, so it is widely used in power system, which provides an effective technical way to improve the reliability of power system.The main content of this paper is to use high-power power electronics technology to improve the power system power supply reliability, including the following aspects:Firstly, a reliable power supply system based on energy storage and diesel generator is studied. The mathematical models and control strategies of each part of the system are analyzed in detail.Energy storage diesel engine coordinated control and so on.The simulation results show that the control performance of the system is good in the process of working state and state switching, and it can effectively improve the power supply reliability of industrial sensitive load.Then the middle and low voltage switching system is studied, which is an important part of the large industrial sensitive load power supply system.This paper introduces the working principle and switching control strategy of 400V/1000kVA hybrid automatic switching switch, and verifies the correctness of various switching control strategies through field experiments and trial runs.The hybrid switch has greatly shortened the switching time of the previous mechanical switch and effectively improved the power supply reliability of the field sensitive load.In this paper, the problem of inrush current in the load switching process of 10kV static converter switch band transformer is studied, the reasons of inrush current are analyzed, and a switching control strategy to eliminate inrush current is proposed.Simulation and experiments show that the proposed strategy can effectively eliminate inrush and avoid switching failure, thus improving the reliability of power supply in 0kV distribution network.The voltage drop time caused by switching is shortened effectively. Both simulation and experiment show that the method is effective and can effectively improve the reliability of power supply for sensitive load in microgrid.It is helpful to improve the reliability index of microgrid power supply.Finally, the dynamic reliability of energy storage type VSC excitation system is studied, and a single machine infinite linearization model of energy storage type VSC excitation control is established, and an active power and reactive power injection control method based on phase compensation is proposed.The advantages and disadvantages of various damping measures and their damping effects are compared and analyzed.Simulation results show that the energy storage VSC excitation system can provide more damping than the conventional thyristor excitation system and the non-energy storage VSC excitation system, and can effectively improve the power angle stability of the power system with small disturbance and large disturbance.An experimental platform for non-energy storage type VSC excitation system is also established, and a preliminary verification experiment is carried out, which lays a foundation for the development of the subsequent industrial prototype.
【学位授予单位】：华中科技大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：TM732

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