新能源并网换流器功率控制稳定机理分析及改进控制策略  

Mechanism Analysis and Improved Strategy of Power Control Stability of Renewable Energy Grid-connected Converters

作　　者：叶伟豪 郭强 赵兵 兰天楷 YE Weihao;GUO Qiang;ZHAO Bing;LAN Tiankai(China Electric Power Research Institute,Beijing 100192,China)

机构地区：[1]中国电力科学研究院有限公司,北京100192

出　　处：《高电压技术》2024年第8期3736-3744,共9页High Voltage Engineering

基　　金：国家自然科学基金(U2166601)。

摘　　要：在大规模新能源并网的背景下,作为并网接口的电压源型换流器得到了广泛应用。为了探究新能源并网换流器接入弱电网的功率控制稳定问题,对比分析了换流器在不同外环控制策略下自身的无功支撑能力对系统静态稳定极限的影响,基于关键电气量之间的数学关系,探究了有功控制的失稳机理,并提出了有功出力变化对无功输出的影响指标。研究结果表明:PQ控制更能适应变化的一次能源出力场景,面对有功出力变化,具有较强的抗扰能力;而PV控制由于具有更高的静态稳定极限,更适合弱电网。此外,为应对新能源出力波动的场景,提出了一种改进控制策略,该策略具有较高的静态稳定极限和无功控制响应速度快的特性,其抗扰能力相较于PV控制得到了提高,最后通过时域仿真进行了验证。Under the background of large-scale renewables being connected to the grid,voltage source converters have been widely used.In order to explore the power control stability problem in weak grids,the influences of the converter’s reactive power support capability on the static stability limit of the system under different outer loop control strategies are compared and analyzed.Based on the relationship between key electrical quantities,this paper explores the instability mechanism of active power control,and puts forward the impact index of active power control changes on reactive power control.The conclusion is drawn that the PQ control can better adapt to changing primary energy output scenarios,and has strong anti-interference ability in the face of active power output changes;however,the PV control is more suitable for the weak grids due to its higher static stability limit.In addition,in order to deal with the scenario of renewable energy fluctuations,an improved control strategy is proposed.This strategy has high static stability limit and fast response speed of reactive power control,and its anti-interference ability is improved compared with that by the PV control.Finally,the results are verified by time domain simulation.

关 键 词：弱电网 电压源型换流器 功率控制 小扰动特性 稳定性分析 小信号模型 

分 类 号：TM46[电气工程—电器]