基于RTDS的有源配电网系统建模与故障特性仿真

发布时间：2018-10-10 09:47

【摘要】：随着分布式电源(DistributedGeneration,DG)的广泛应用,有源配电网变得越来越普遍。与传统配电网相比,有源配电网的结构更加复杂,其故障特性也发生了明显变化,特别是逆变型分布式电源(Inverter-Based Distributed Generation,IBDG)的故障特性与传统电源相比具有显著差异。为研究开发适应于有源配电网的保护方案和装置,有必要对有源配电网的故障特性进行全面、准确的分析。因此,本文以实时数字仿真系统(Real-Time Digital Simulator,RTDS)为工具,围绕有源配电网系统建模和故障特性仿真开展研究。主要工作如下:基于RTDS建立有源配电网系统仿真模型。首先以光伏电源(Photovoltaic,PV)为例,搭建了 IBDG的仿真模型,包括主要一次设备和控制系统;然后以典型的辐射型配电网结构为例,搭建了有源配电网系统仿真模型,含2个恒功率(PQ)控制的IBDG。有源配电网故障仿真和故障特性分析。利用建立的有源配电网系统模型,全面仿真不同故障条件下的相间短路,包括故障类型、故障位置、过渡电阻等因素的影响;通过对仿真数据进行相量和序分量计算,直观地分析有源配电网电压、电流相量及相应序分量的大小及分布特点。仿真结果表明,IBDG的接入使得有源配电网的故障特性与传统配电网具有较大的差异,过渡电阻能够影响并网点的电压跌落及故障点两端正序电流的夹角。有源配电网故障的解析计算及对仿真结果的验证。在计及控制策略影响的前提下,用受控电流源作为IBDG的故障等值模型,并给出其故障电流的计算方法;建立不同故障类型下含IBDG有源配电网的等值电路,采用网孔电流法建立电压电流方程,并对方程进行迭代求解。理论计算结果验证了仿真结果的正确性。构建基于RTDS的有源配电网闭环测试平台。以提出的有源配电网仿真模型为基础,设计了闭环测试平台的整体结构,介绍了 RTDS相关板卡的使用方法及整体控制逻辑;利用该测试平台对某一保护装置进行了闭环测试,验证了方案的可行性。
[Abstract]:With the wide application of distributed generation (DistributedGeneration,DG), active distribution network becomes more and more common. Compared with the traditional distribution network, the structure of the active distribution network is more complex, and the fault characteristics of the active distribution network have changed obviously, especially the fault characteristics of the inverter distributed generation (Inverter-Based Distributed Generation,IBDG) are significantly different from those of the traditional power supply. In order to research and develop protection schemes and devices suitable for active distribution network, it is necessary to analyze the fault characteristics of active distribution network comprehensively and accurately. Therefore, this paper focuses on the modeling and fault characteristic simulation of active distribution network system with real time digital simulation system (Real-Time Digital Simulator,RTDS) as a tool. The main work is as follows: the simulation model of active distribution network system based on RTDS is established. Firstly, taking photovoltaic power supply (Photovoltaic,PV) as an example, the simulation model of IBDG is built, including the primary equipment and control system, and then the simulation model of active distribution network system is built with the typical radiation distribution network structure as an example. IBDG. with two constant Power (PQ) controls Fault simulation and fault characteristic analysis of active distribution network. By using the established active distribution network system model, the phase short circuit under different fault conditions, including the influence of fault type, fault location, transition resistance and so on, is simulated, and the phasor and sequence components of the simulation data are calculated. The size and distribution characteristics of voltage, current phasor and corresponding sequence components in active distribution network are analyzed intuitively. The simulation results show that the connection of IBDG makes the fault characteristics of the active distribution network quite different from that of the traditional distribution network, and the transient resistance can affect the voltage drop and the angle of the positive sequence current at the two ends of the fault point. The analysis and calculation of the active distribution network fault and the verification of the simulation results. On the premise of considering the influence of control strategy, the controlled current source is used as the fault equivalent model of IBDG, and the calculation method of its fault current is given, and the equivalent circuit of active distribution network with IBDG under different fault types is established. The voltage and current equation is established by the mesh current method and the equation is solved iteratively. The results of theoretical calculation verify the correctness of the simulation results. The closed loop test platform of active distribution network based on RTDS is constructed. Based on the proposed simulation model of active distribution network, the whole structure of the closed-loop test platform is designed, the use method of RTDS related board and the whole control logic are introduced, and the closed-loop test of a protective device is carried out by using the test platform. The feasibility of the scheme is verified.
【学位授予单位】：山东大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM727

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