基于主动电压抬升的光伏全直流汇集与送出系统网侧故障穿越策略
Fault Ride-Through Strategy for PV Full DC Collection and Transmission System Based on Active Voltage Rising Method
史兴华 1张雪垠 2甘纯 1马已青 2闻旭东 1段金沛 2赵彪2
作者信息
- 1. 国网浙江省电力有限公司电力科学研究院,浙江 杭州 310014
- 2. 清华四川能源互联网研究院,四川成都 610213
- 折叠
摘要
光伏(PV)全直流汇集与送出系统中,高压直流(HVDC)侧发生短路故障导致功率消纳能力下降,光伏无法及时感知故障而功率不变,导致系统过压停运.为解决此问题,提出了一种基于主动电压抬升的故障穿越策略,当高压直流变压器高压侧子模块电压上升到某一水平时,增加中压侧投入的子模块总数以提升中压直流电压,配合具有故障态P-V下垂特性的最大功率点跟踪(MPPT)装置,实现子模块未过压情况下最大功率点跟踪进入限功率模式,实现高压直流变压器端口功率平衡,达到降低子模块过压、完成故障穿越的效果.对所提策略下HVDC变压器子模块过压进行了分析,并仿真验证了策略的有效性和必要性.
Abstract
In the photovoltaic(PV)full DC collection and transmission system,a short circuit fault on the high voltage DC(HVDC)side will lead to a decrease in power absorption capacity of the high voltage side DC grid.PVs cannot detect the fault of the high voltage side DC grid in time,therefore its output power remains unchanged,which results in the system overvoltage and causes the system to shut down.To address this problem,a fault ride through strategy based on the active voltage rise is proposed.While the voltage of the high voltage side submodule of the high voltage DC transformer is risen to a certain level,the number of the medium voltage side submodules which output the high voltage level is increased to rise the voltage of the medium DC bus.And with the maximum power point tracking(MPPT)converters which have the function of fault state P-V droop,the MPPTs enter the power limiting mode in advance to achieve the power balance of the high voltage DC transformer,thus reduces the overvoltage of the submodule capacitor,and achieves the fault ride through function.The overvoltage of the HVDC transformer submodule under the proposed strategy is analyzed,and the effectiveness and necessity of the strategy are verified by simulation.
关键词
光伏全直流汇集与送出/高压直流变压器/最大功率点跟踪装置/过电压/P-V下垂/故障穿越Key words
PV full DC collection and transmission/high voltage DC transformer/maximum power point tracking converter/overvoltage/P-V drop/fault ride through引用本文复制引用
基金项目
国家电网浙江省电力公司项目(5211DS230005)
出版年
2024
国家科技期刊平台
NSTL
万方数据