电工技术学报2025，Vol.40Issue(5)：1355-1367,13.DOI:10.19595/j.cnki.1000-6753.tces.240238
基于协同控制优化风电-柔直并网惯性响应策略研究
Optimization of Inertia Response Strategy Based on Synergetic Control for Wind Power Integrating to Power Grid via VSC-HVDC
摘要
Abstract
Wind farms integrating into receiving grid via voltage sourced converter based high voltage direct current(VSC-HVDC)has become a main operating mode.However,VSC-HVDC causes the decoupling of the wind farm side VSC(WFVSC)frequency from the receiving grid frequency and,hence,wind farms cannot quickly perceive frequency disturbances in the receiving power grid without communication and use additional frequency regulation control to provide inertia support and frequency response.Recently,some non-communication methods were presented to couple the frequency of wind farms with the receiving power grid to provide inertia support,but most of them didn't discuss how to design parameters.To address this issue,this paper proposes a key parameter design method for wind farms integrating into receiving grid via VSC-HVDC to provide non-communication coordinated inertia support and optimize the dynamic characteristics of inertial response. Firstly,based on the variable proportion coefficient rotor speed regulation of doubly fed induction generators(DFIGs)and the additional DC voltage-frequency droop control of the grid side VSC(GSVSC)station,the non-communication coordinated frequency response transfer functions of VSC-HVDC connected wind farm are derived.The role of the droop coefficient ku of GSVSC and speed regulation coefficient kwi of DFIGs in providing inertia response for receiving grid is analyzed.Then select frequency deviation,DC voltage deviation and virtual inertia of wind farms connected to VSC-HVDC as macro variables according to synergetic control theory.Further,synergistic control law of ku is designed to adapt to frequency change while synergistic control law of kwi is designed to adapt to DC voltage change and rotor speed change,which makes the coordinated inertia provided by capacitor energy storage and differential rotor kinetic energy. Simulation results in WSCC-9 bus system show that,the lowest frequency increases to 49.822 Hz and the rate of change of frequency(RoCoF)decreases to-0.284 Hz/s under the proposed strategy.Compared with fixed coefficient controls,the system frequency deviation is reduced by 5.4%and RoCoF is reduced by 1.1%,which verifies the effectiveness of the proposed strategy in improving the inertia support ability and optimizing the dynamic response characteristics.Furthermore,ku in proposed strategy rapidly increases in the early stage and provides significant support with a virtual inertia of 5.668 s.As the system frequency recovers,ku gradually decreases to zero,reducing the DC voltage deviation and the energy required for DC capacitor voltage recovery.The voltage is restored to the rated value faster,and the DC voltage recovery time is reduced by 31.3%.In the early stage of frequency disturbance,kwi quickly reaches its peak,and DFIGs quickly release the rotor kinetic energy to provide maximum inertia support.As the frequency recovers,kwi gradually decreases to zero to avoid excessive release of rotor kinetic energy,and the rotor speed recovery time decreases by 18.7%.At the same time,kwi of DFIGs in high wind speeds are larger than those in low wind speeds,which means each DFIG adapts to the difference in rotor kinetic energy to provide appropriate inertia support.Finally,considering the randomness of wind power,random fluctuations are added to the input wind speeds.The results show that the proposed strategy is applicable under random wind speeds. The following conclusions can be drawn from the simulation analysis:(1)Compared with fixed coefficient controls,the proposed strategy can not only improve the collaborative cooperation inertia support between VSC-HVDC and wind farms with differential rotor kinetic energy when suffering frequency disturbances,but also optimize the dynamic characteristics of the receiving grid inertia response.(2)The proposed strategy can optimize the dynamic recovery process of DC capacitor voltage after inertia support,and help wind farms quickly recover rotor kinetic energy and maximum power point tracking(MPPT)operation mode while avoiding secondary disturbances.关键词
风电场/柔性直流输电(VSC-HVDC)/惯性响应/协同控制Key words
Wind farm/voltage source converter based high voltage direct current transmission(VSC-HVDC)/inertia response/synergetic control分类
动力与电气工程引用本文复制引用
谭珺敉,彭晓涛,李旭涛,陈紫薇,杨军..基于协同控制优化风电-柔直并网惯性响应策略研究[J].电工技术学报,2025,40(5):1355-1367,13.基金项目
国家自然科学基金项目(52237004)和国家电网公司总部科技项目(1400-202235243A-1-1-ZN)资助. （52237004）
