推导了ab 变换和dq0变换间存在对偶的变换特性，利用两者间的相互变换能解决某一类型的交叉耦合问题。针对基于dq0系统统一电能质量调节器(unified power quality conditioner，UPQC)模型中存在双环强耦合问题，证明了该耦合问题可通过ab 和dq0间的变换实现完全解耦。在此基础上提出了基于两相同步旋转dq坐标系的UPQC完全解耦的新型控制策略，控制过程中由于dq两相完全解耦，使控制更加简单、易实现，控制品质得到提高。大量基于EMTDC/PSCAD软件的仿真证明了该控制方法的有效性。

Dual transformation character was deduced from the relationship between ab transformation and dq0 transformation. It can be used to deal with a category of cross coupling problems. The double-loop strong coupling problem exists in the model of unified power quality conditioner (UPQC) based on dq0 system. By transformation between ab and dq0, it is deducted and proved that the cross coupling problem can be decoupled completely. A novel control strategy of UPQC based on the two-phase synchronous rotating dq coordinate system was proposed, through which the entire decoupling could be achieved. As each of dq phases can be completely decoupled during the control process, the control would be simpler, easier to be realized and meanwhile the control quality would be significantly improved. The validity and correctness of such control strategy were proved by lots of simulation results using EMTDC/PSCAD software.

国家自然科学基金项目(90610024，50467002，50347026)；云南省科技攻关项目(2003GG10)；云南省自然科学基金项目(2005F0005Z，2004E0020M，2002E0025M)。