电力系统自动化
電力繫統自動化
전력계통자동화
AUTOMATION OF ELECTRIC POWER SYSTEMS
2015年
11期
166-172
,共7页
武健%刘瑜超%徐修林%徐殿国
武健%劉瑜超%徐脩林%徐殿國
무건%류유초%서수림%서전국
模块化多电平换流器%直流输电%三相不平衡%环流抑制
模塊化多電平換流器%直流輸電%三相不平衡%環流抑製
모괴화다전평환류기%직류수전%삼상불평형%배류억제
modular multilevel converter (MMC)%direct current (DC) transmission%three-phase unbalanced%circulating current suppression
模块化多电平换流器(MMC)在中高压直流输电中得到了广泛的研究和应用。三相不平衡交流电网下的功率波动引起 MMC 三相桥臂能量不均衡,导致内部环流的产生。针对三相不平衡直流输电系统,对 MMC 内部环流的产生机理进行了理论推导和分析,并根据内部环流的特点,将比例—积分控制与重复控制相结合,提出了一种基于正、负序双同步旋转坐标系下复合控制的环流抑制方法。该方法同时适用于三相平衡和三相不平衡系统。同时,为了提高三相不平衡条件下直流输电系统的波形质量,引入了基于 dq 解耦控制的负序电流补偿方法。仿真结果证明,无论交流系统侧三相是否平衡,该控制策略对环流都具有良好的抑制效果,同时能够确保系统交流侧的三相电流保持平衡。
模塊化多電平換流器(MMC)在中高壓直流輸電中得到瞭廣汎的研究和應用。三相不平衡交流電網下的功率波動引起 MMC 三相橋臂能量不均衡,導緻內部環流的產生。針對三相不平衡直流輸電繫統,對 MMC 內部環流的產生機理進行瞭理論推導和分析,併根據內部環流的特點,將比例—積分控製與重複控製相結閤,提齣瞭一種基于正、負序雙同步鏇轉坐標繫下複閤控製的環流抑製方法。該方法同時適用于三相平衡和三相不平衡繫統。同時,為瞭提高三相不平衡條件下直流輸電繫統的波形質量,引入瞭基于 dq 解耦控製的負序電流補償方法。倣真結果證明,無論交流繫統側三相是否平衡,該控製策略對環流都具有良好的抑製效果,同時能夠確保繫統交流側的三相電流保持平衡。
모괴화다전평환류기(MMC)재중고압직류수전중득도료엄범적연구화응용。삼상불평형교류전망하적공솔파동인기 MMC 삼상교비능량불균형,도치내부배류적산생。침대삼상불평형직류수전계통,대 MMC 내부배류적산생궤리진행료이론추도화분석,병근거내부배류적특점,장비례—적분공제여중복공제상결합,제출료일충기우정、부서쌍동보선전좌표계하복합공제적배류억제방법。해방법동시괄용우삼상평형화삼상불평형계통。동시,위료제고삼상불평형조건하직류수전계통적파형질량,인입료기우 dq 해우공제적부서전류보상방법。방진결과증명,무론교류계통측삼상시부평형,해공제책략대배류도구유량호적억제효과,동시능구학보계통교류측적삼상전류보지평형。
The modular multilevel converter (MMC) has been widely researched and applied in high-voltage direct-current (HVDC) transmission.MMC three-phase bridge arm energy imbalance is caused by power fluctuations in the three-phase unbalanced alternating current(AC) grid,which generates internal circulating current.In light of the three-phase unbalanced DC transmission system,the internal circulating current mechanism of MMC is derived and analyzed.According to the characteristics of internal circulating current,a compound control method combining proportional-integral (PI) control and repetitive control is proposed for circulating current suppression based on positive and negative sequence in a double synchronous rotating coordinate system.This method is suitable for both three-phase balanced and three-phase unbalanced systems.Meanwhile,in order to improve the waveform quality of the direct current(DC)transmission system under the three-phase unbalanced condition,the negative sequence current compensation method based on dq decoupling control is introduced. The simulation results have verified that no matter whether the AC system three phases are balanced or not,the control strategy always has good performance in circulating current suppression,while ensuring the balance of the system”s three-phase AC. This work is supported by the State Key Program of National Natural Science Foundation of China(No.5 1237002).