一种新的谐波检测方法及其在APF中的应用

有源电力滤波器作为改善电能质量的装置被广泛地应用在各种场合,其中谐波检测环节在有源滤波器中扮着重要角色。针对在网侧电压波形发生畸变、幅值跌落等恶劣环境中,传统锁相环无法准确对电压相位进行锁相的情况,提出一种基于双同步坐标系解耦的柔性锁相环的有效值谐波检测方法,并在模拟某相电压跌落和相位偏移的情况下,将其与基于传统锁相环的方均根值谐波检测方法进行对比分析。仿真结果表明,此方法是可行的,可以在电网恶劣环境下,准确检测出电网电压正序基波电压的相位信息,同时将其应用于有源电力滤波器中,网侧谐波的补偿达到了预期的效果。

A New Harmonic Detection Method and Its Application in Active Power Filter

Active power filter,a device for improving power quality,is used widely in various occasions, in which the harmonics detection plays an important role in the active filters. Aiming to such severe condi-tion as voltage wave distortion and amplitude drop at the network side and the case of not locking voltage phase accurately by traditional phase locked loop (PLL),a kind of Root-Mean-Square(RMS)harmonic detection method based on Decoupled Double Synchronous Reference Frame Software Phase Locked Loop(DDSRF-SPLL) is proposed. And it is compared with RMS harmonic detection method based on PLL in case of simulating voltage drop and phase shift. It is shown by the simulation result that this method is feasible and can detect the phase information of positive sequence fundamental voltage of grid voltage accurately at severe condition and,at the same time,it is used in the active power filter and desired compensation result of harmonics at the grid side is achieved.