面向高渗透率分布式光伏的分层储能系统布局配置优化研究

In the application scenario of Distributed PV integrated in the Grid with high penetration, harmonic current produced by multiple inverters connect to the Grid has a significant effect on distribution network, as well as the problems of voltage fluctuations, flow distribution, power quality, load forecasting and demand-side management. System stability with multiple inverters integrated in the Grid and decentralized coordinated control of wide distributed PV units have turned into critical problems. Based on the four-quadrant regulation ability, scientific distribution and capacity optimization are the basis and prerequisite, which improve the application of energy storage technology in smart distribution network field. Consideration to capacity advantage of large-scale centralized energy storage and flexible layout and clustering effect of distributed energy storage, the conception of hierarchical energy storage system is proposed. It is beneficial to capacity optimization and improving the utilization of energy storage device. This project oriented to PV integrated in Grid with a high penetration, solving problems such as capacity-load ratio of PCC(points of common connection), grid voltage stability and multiple inverters parallel cluster control by way of researching on the structure of hierarchical energy storage system storage, launching basic technology research on distribution principle, clustering effect, cluster coordination control mechanism and capacity optimization of hierarchical energy storage integrated in the Grid with a high penetration. Such research should provide a technology basis for flexible control, life extending of the energy storage system and the scheduled ability of PV generation.

在高渗透率分布式光伏并网应用场景下，多逆变器综合并网产生的谐波电流对配电网影响显著，同时存在电压波动、潮流分布、电能质量、负荷预测以及需求侧管理等问题，而保持多逆变器接入的系统稳定以及广域分布光伏单元的协调控制成为亟待解决的问题。基于储能装置四象限调节功能进行储能系统的合理布点及容量优化配置，是储能技术在智能配电网领域应用的前提与基础；兼顾集中储能的大规模容量优势与分布式储能的灵活布局及集群效应，提出分层储能概念，有利于实现储能系统容量及配置优化，提高储能装置利用率。项目依托高渗透率光伏接入场景，针对联络点容载比、电网电压稳定、以及多逆变器并联集群控制等问题，设计分层储能架构，开展分层储能系统在高渗透分布式电源并网应用场景下的布点原理、汇聚效应与集群协调控制机理、容量优化配置等基础技术研究，为实现储能系统柔性控制、延长储能系统使用寿命、提升电网对光伏电源的就地消纳能力提供技术依据。

随着分布式光伏发电系统在配电网的高渗透率的并网应用，配电网不再是传统的“无源”状态，原本不需要考虑的电网稳定运行问题，也可能出现在不同电压等级和不同负荷情况下的配电网络。依托分层储能这一联合应用模式，将为解决此类问题提供有效途径。研究首先从调研“高渗透率”的概念着手，采取遍历仿真典型网络的方式，量化分析面向配电网的高渗透率下的光伏发电系统规模，以期得到统计规律；提出了三层拓扑架构的分层储能系统，并从是否响应电网调度、系统规模等角度，界定了分层结构的原则和依据；基于Digscilent仿真软件和Matlab仿真平台，对不同层级的储能系统分别采用粒子群搜索算法寻找对评价指标影响灵敏度最高的点，并记录该点为储能装置基点，进而提出储能系统的选点布局依据和方法；通过IEEE 33节点系统进行仿真验证，并对比分析集中式、分布式和分层储能系统各自优缺点；研究了多机PCS并联控制机理，应用下垂控制策略实现储能变流器并联系统的安全稳定运行；将电力系统线路的广域特性参数等因素作为影响能量传输和分布的重要因素进行综合考虑，研究了多点布局分布式储能系统的广域特性与汇聚特性，实现动态能量的再分配；研究在统一储能出力需求情况下多储能系统变流器的功率耦合机理，建立了多个变流器并联运行的特性模型，通过对模型特性进行分析，研究了各储能系统的能量流动规律。