基于Fryze功率定义的三相系统广义无功实时检测方法

Fast Harmonics Detection for Three-Phase System Based on Fryze Power Definition

以Fryze非正弦单相系统下的功率定义为指导思想,将其进行扩展,得到三相系统的非正弦周期电流的时域分解方法,同时提出动态平均功率和电压有效值的计算方法,消除了一般意义上的一个周期的延时。当电压电流无畸变并平衡时,测量有功电流无过渡过程,是实时精确的;当系统对称,电压无畸变,电流有畸变时,测量的过渡过程为1/3个周期;当电流只含有奇数次谐波时的过渡过程仅为1/6个周期;当系统不平衡,电压对称无畸变,电流畸变时,测量的过渡过程为1个周期。仿真验证了这种算法的正确性和有效性。

On the basis of Fryze＇ s power definition under single-phase nonsinusoidal condition, an expanded decomposition approach in time domain for the nonsinusoidal period current in three-phase systems is proposed, in which the calculations for dynamic average power and dynamic voltage virtual value eliminate the one-period delay in common sense. In the sinusoidal systems, active current detecting is real-time with no delay. In the symmetry system having symmetry voltage and aberrance current, the detecting transition process is declined to 1/3 of the work period. When the aberrance currents only have odd harmonics, the detecting transition process is declined to 1/ 6 of the work period. In the imbalance system having symmetry voltage and aberrance current, the detecting transition is the work period. The correctness and validity of the proposed measurement approach are clearly shown by the simulation studies.