电机与控制学报
電機與控製學報
전궤여공제학보
ECTRIC MACHINES AND CONTROL
2014年
2期
1-7
,共7页
许德志%汪飞%阮毅%毛华龙%张巍%杨影
許德誌%汪飛%阮毅%毛華龍%張巍%楊影
허덕지%왕비%원의%모화룡%장외%양영
三相并网逆变器%输出阻抗模型%非线性因素%交互影响分析%谐波谐振
三相併網逆變器%輸齣阻抗模型%非線性因素%交互影響分析%諧波諧振
삼상병망역변기%수출조항모형%비선성인소%교호영향분석%해파해진
three-phase grid-connected inverter%output impedance model%nonlinear factors%interactive influence analysis%harmonic resonance
针对大量分布式并网逆变器接入到公共电网时逆变器侧与网侧之间的交互影响问题，从并网逆变器闭环系统外特性角度入手，提出在同步旋转坐标系下对LCL型三相并网逆变器入网电流和滤波电容电流双闭环系统进行输出阻抗建模。利用前馈解耦策略，将dq轴控制环路之间的耦合阻抗消除。考虑到实际系统多采用数字系统，将数字控制延时引入到模型中以更加精确地反映实际并网逆变器的输出阻抗特性。基于无dq环路阻抗耦合和引入数字控制延时情况下的精确输出阻抗模型，对多逆变器并网系统进行阻抗网络建模、谐振机理剖析及谐波交互影响分析。理论分析结果表明，逆变器产生谐波成分与电网电压谐波成分会加剧多模块并网系统入网电流的谐波畸变。仿真结果验证了所建输出阻抗模型的正确性及其在逆变器-电网交互系统性能分析中的有效性。
針對大量分佈式併網逆變器接入到公共電網時逆變器側與網側之間的交互影響問題，從併網逆變器閉環繫統外特性角度入手，提齣在同步鏇轉坐標繫下對LCL型三相併網逆變器入網電流和濾波電容電流雙閉環繫統進行輸齣阻抗建模。利用前饋解耦策略，將dq軸控製環路之間的耦閤阻抗消除。攷慮到實際繫統多採用數字繫統，將數字控製延時引入到模型中以更加精確地反映實際併網逆變器的輸齣阻抗特性。基于無dq環路阻抗耦閤和引入數字控製延時情況下的精確輸齣阻抗模型，對多逆變器併網繫統進行阻抗網絡建模、諧振機理剖析及諧波交互影響分析。理論分析結果錶明，逆變器產生諧波成分與電網電壓諧波成分會加劇多模塊併網繫統入網電流的諧波畸變。倣真結果驗證瞭所建輸齣阻抗模型的正確性及其在逆變器-電網交互繫統性能分析中的有效性。
침대대량분포식병망역변기접입도공공전망시역변기측여망측지간적교호영향문제，종병망역변기폐배계통외특성각도입수，제출재동보선전좌표계하대LCL형삼상병망역변기입망전류화려파전용전류쌍폐배계통진행수출조항건모。이용전궤해우책략，장dq축공제배로지간적우합조항소제。고필도실제계통다채용수자계통，장수자공제연시인입도모형중이경가정학지반영실제병망역변기적수출조항특성。기우무dq배로조항우합화인입수자공제연시정황하적정학수출조항모형，대다역변기병망계통진행조항망락건모、해진궤리부석급해파교호영향분석。이론분석결과표명，역변기산생해파성분여전망전압해파성분회가극다모괴병망계통입망전류적해파기변。방진결과험증료소건수출조항모형적정학성급기재역변기-전망교호계통성능분석중적유효성。
Aiming at the interactive influence problems between inverter side and grid side when a large number of inverters are connected to the utility grid, from the standpoint of external characteristics, out-put impedance model of three-phase grid-connected inverter with LCL filters based on dual-loop control scheme of grid current and filter capacitor current were firstly proposed and deduced in the synchronous rotating reference frame. Then the feed-forward decoupling control strategy was introduced to eliminate the coupling impedances between the d and q axis control loop. Because the real system would be a digit-al control system, the control delay was modeled and incorporated into the developed model in order to improve the accuracy of output impedance characteristics. Based on the accurate output impedance model proposed above, the interactive influences and its harmonic resonance mechanism between the multiple inverter systems and the utility grid were modeled and analyzed. Theoretical analysis indicates that the harmonic components form inverter side or grid side will aggravate the grid current distortion in distributed generation system based on multi modules. Simulation results are presented to demonstrate the correctness and effectiveness of the output impedance modeling and system performance analysis method based on dis-tributed interactive network.
