第 51 卷 第 16 期 電力系統(tǒng)保護(hù)與控制 Vol.51 No.16
2023 年 8 月 16 日 Power System Protection and Control Aug. 16, 2023
DOI: 10.19783/j.cnki.pspc.230103
弱電網(wǎng)下基于諧波狀態(tài)空間模型的光儲-虛擬同步發(fā)電機(jī)
穩(wěn)定性分析與優(yōu)化控制研究
楊 效 1
,曾成碧 1
,賴 輝 1
,吳雪峰 1
,苗 虹 1
,劉文飛 2
,楊 勇 2
(1.四川大學(xué)電氣工程學(xué)院,四川 成都 610065;2.國網(wǎng)甘肅省電力公司電力科學(xué)研究院,甘肅 蘭州 730050)
摘要:虛擬同步發(fā)電機(jī)(virtual synchronous generator, VSG)技術(shù)因提供阻尼和慣量而被廣泛用于新能源并網(wǎng)逆變
器。光儲并入弱電網(wǎng)易發(fā)生頻率耦合等問題,因而 VSG 并網(wǎng)穩(wěn)定性分析變得更加復(fù)雜。針對光儲并入弱電網(wǎng)系統(tǒng),
考慮頻率耦合,在 dq 域中建立基于諧波狀態(tài)空間(harmonic state space, HSS)理論的多時間尺度虛擬同步發(fā)電機(jī)模
型。采用歸一化參數(shù)靈敏度分析法,揭示功率環(huán)、電壓環(huán)和低通濾波中虛擬慣量 J、虛擬阻尼 Dp、下垂系數(shù) Ku、
比例系數(shù) kpu 和截止頻率?c 等關(guān)鍵控制參數(shù)根軌跡的特性和電網(wǎng)強(qiáng)度對系統(tǒng)穩(wěn)定性的影響。并通過調(diào)整優(yōu)化控制
參數(shù),提高系統(tǒng)穩(wěn)定性。最后在 Matlab/Simulink 仿真平臺驗(yàn)證諧波狀態(tài)空間模型精確度和關(guān)鍵參數(shù)根軌跡特性。
關(guān)鍵詞:虛擬同步發(fā)電機(jī);弱電網(wǎng);諧波狀態(tài)空間;穩(wěn)定性分析
A stability analysis method and optimal control of a photovoltaic energy storage-virtual synchronous
generator based on a harmonic state space model in a weak grid
YANG Xiao1
, ZENG Chengbi1
, LAI Hui1
, WU Xuefeng1
, MIAO Hong1
, LIU Wenfei2
, YANG Yong2
(1. College of Electrical Engineering, Sichuan University, Chengdu 610065, China; 2. Electric Power Research
Institute of State Grid Gansu Electric Power Company, Lanzhou 730050, China)
Abstract: Virtual synchronous generator (VSG) technology is widely used in the control of new energy grid-connected
inverters because it provides damping and inertia. It is easy to cause frequency coupling when photovoltaic energy storage
systems are connected to a weak grid, so analyzing the grid-connected stability of a VSG becomes more complicated. For
photovoltaic energy storage systems connected to a weak grid, a multi-time scale VSG model based on harmonic state
space (HSS) theory is established in the dq domain considering frequency coupling. The normalized parameter sensitivity
analysis method is used to reveal the characteristics of root locus of key control parameters such as virtual inertia J, virtual
damping Dp, droop coefficient Ku, proportional coefficient kpu and cut-off frequency ?c in power loop, voltage loop and
low-pass filter, and the influence of power grid strength on system stability. The control parameters are adjusted and
optimized to enhance system stability. Finally, the accuracy of the harmonic state space model and the root trajectory
characteristics of the key parameters are verified on the Matlab/Simulink simulation platform.
This work is supported by the Key Research and Development Program of Sichuan Province (No. 2023YFG0198).
Key words: virtual synchronous generator; weak power grid; harmonic state space; stability analysis
0 引言
虛擬同步發(fā)電機(jī)(virtual synchronous generator,
VSG)控制模擬同步機(jī)動態(tài)特性解決新能源并網(wǎng)導(dǎo)
致慣量和阻尼不足而引發(fā)的穩(wěn)定性問題。光儲新能
基金項(xiàng)目:四川省重點(diǎn)研發(fā)項(xiàng)目資助(2023YFG0198);國家
電網(wǎng)有限公司科技項(xiàng)目資助(52272222001J)
源常分布于偏遠(yuǎn)地區(qū),電網(wǎng)呈現(xiàn)高感抗弱電網(wǎng)特性,
弱電網(wǎng)下并網(wǎng)換流器易發(fā)生諧振等穩(wěn)定性問題[1-4],
給光儲-VSG 的穩(wěn)定帶來新的挑戰(zhàn)。
建立系統(tǒng)的精準(zhǔn)數(shù)學(xué)模型是分析弱電網(wǎng)下光
儲-VSG 穩(wěn)定的前提。目前 VSG 并網(wǎng)系統(tǒng)的建模方
法主要有阻抗模型法、狀態(tài)空間法[5-8]。阻抗模型法
的物理意義明確、分析便捷,但阻抗模型難以獲取
控制參數(shù)對振蕩模態(tài)的靈敏度信息,存在局限性[9]。