【作者】 张斌；

【导师】 文明浩；

【作者基本信息】 华中科技大学 ， 电力系统及其自动化， 2011， 硕士

【摘要】 静止同步补偿器(STATCOM)技术是电力系统无功补偿的一种有效手段,具有补偿性能好、动态响应速度快,运行范围宽的特点,能对电力系统中的稳定以及快速变动的无功负荷进行快速的补偿,目前已得到越来越广泛的应用。为实现对无功负荷的高效补偿,研究无功补偿装置的拓扑结构和接入方式,优化系统结构和电路参数,并根据其补偿机理和数学模型提出行之有效的控制策略等,对STATCOM技术的研究而言具有重要的意义。本文将主要围绕上述问题展开研究工作。本文提出在电力系统高低电压等级交汇点的配电变压器处采用配电变一体化STATCOM(以下简称DT-STATCOM)的接入方式和技术,从而能对配电网负荷实现集中高效的无功补偿。通过对DT-STATCOM系统的主电路拓扑结构、电路参数优化等方面的研究,表明DT-STATCOM技术能有效地降低装置的接入电压,从而有利于选择最优的功率器件参数和主电路拓扑结构。通过多模块协调和并联运行方式,解决了提高装置补偿容量和降低系统损耗的问题。在主电路结构上,提出利用配电变压器的绕组抽头接入漏感来充当装置输出滤波器的连接电感,节省了额外的后级电感,改善了滤波环节的设计,并依据一定的优化原则得到DT-STATCOM主电路各参数的取值范围。基于DT-STATCOM拓扑结构的特殊性,重点对DT-STATCOM通过配电变压器抽头接入方式进行无功补偿的工作机理进行了阐述,并在基于等效电路建立了DT-STATCOM系统的输入—输出数学模型,从其数学模型出发,给出了基于功率平衡的电流跟踪控制方法。基于功率平衡的控制策略利用变压器低压负载侧和高压供电侧的电气量信息进行综合计算构造补偿电流指令,从原理上可适用于补偿装置不同的抽头接入方式和接入位置,具有更好的适用性,同时也具有较好的电流动态跟踪能力。为对DT-STATCOM系统的补偿机理、稳态和动态特性以及主电路结构参数进行仿真研究,基于MATLAB中的Simulink工具箱建立了DT-STATCOM仿真模型,通过系统仿真验证了配电变一体化接入方式和基于功率平衡的无功电流跟踪控制方法的有效性,也促进了一体化结构系统主电路参数的优化设计。在仿真研究的基础上,建立了1.1MVA/10/0.4kV配电变压器和DT-STATCOM模块组成的动模实验系统,进行了DT-STATCOM系统空载损耗检测试验,试验结果表明,DT-STATCOM系统空载损耗检测值低于配电变压器额定容量的1%,满足课题提出的损耗技术指标要求。最后,本文对上述研究工作做了总结,指出了下一步需要开展的研究工作。更多还原

【Abstract】 The technique of Static Synchronous Compensator (STATCOM) is an effective way for reactive power compensation in power system. It performs well in compensation with fast dynamic response and board operating range, which makes it possible to compensate stable or varying reactive power rapidly. Because of its characteristic, STATCOM is now using more and more widely in power system. In order to provide highly effective compensation, it’s important to study the topology structure and integrating method of the compensating system, optimize system structure and circuit parameters, and provided feasible control strategy according to the compensating mechanism and the mathematical model of compensating system. This paper focused on the problems above and started relevant researching.This paper proposed the integrating method and technique of STATCOM integrated with distribution transformer (DT-STATCOM) at the high-low voltage crossing point in power system, which realized intensive compensation for distribution load. Study on main circuit topology structure and parameter optimization of DT-STATCOM indicated that the technique of DT-STATCOM was able to lower the integrating voltage effectively, which helps to select the most suitable parameters of power electronic devices and improve main circuit structure design. Using multiple-module coordination and parallel operating method can also solve problems of raising compensating capability and reducing system loss. This paper proposed that the leakage reactance of distribution transformer tapped winding could be used as the second reactance of LCL output filter. In this way it could save an additional filter second reactance, which helped to improve the design of filter. Based on certain principles the range of DT-STATCOM main circuit parameters was decided.According to the special topology structure of DT-STATCOM, this paper stressed on representing DT-STATCOM’s working mechanism while it is integrated with distribution transformer tapped windings. System input-output mathematical model was built up under DT-STATCOM’s equivalent circuit. The mathematical model raised a current-tracing controlling strategy basing on power balance theory. This controlling strategy calculated compensating current reference with electrical quantity from both low voltage side and high voltage side of transformer. In this way the controlling strategy could be available for different tapping winding integrating method, have board applicability and good dynamic current-tracing ability.In order to start simulating study of the compensating mechanism, steady state characteristics, dynamic state characteristics and main circuit parameters of DT-STATCOM, this paper built up a DT-STATCOM simulating model with Simulink workbox in MATLAB. System simulation proved the effectiveness of compensating structure integrated with distribution transformer and the current-tracing controlling strategy basing on power balance theory. Simulating work also improved optimal design of system structure and circuit parameters.On the foundation of simulating research, a dynamic-simulating experiment system was built with 1.1MVA/10/0.4kV distribution transformer and DT-STATCOM module. DT-STATCOM system no-load loss measuring experiment was perform, the result of which indicated that measured value of no-load loss of DT-STATCOM system was below 1% of distribution transformer’s rated capacity.The last part of this paper stated conclusions of research work above, and give out the possible research work in the future.更多还原