A series active power filter adopting hybrid control approach

The series active power filter (APF) is suitable for compensating voltage t ype harmonics-producing load, whereas the control approach it adopts may di rectly influence its compensation characteristics. This paper first discuss es the control approach of detecting source current in terms of the basic o peration principle of a series APF, then developing a control approach of d etecting load voltage. On the basis of these, a hybrid control approach is proposed. In this approach, the reference signal of the compensation voltag e needed by the series APF is obtained by detecting both source current and load voltage. Thus, this approach has the advantages of the first and the second control approaches and at the same time, it can overcome their respe ctive drawbacks. For practical realization, the control methods of PWM inve rter in the series APF and for regulating its de side voltage are discussed in detail. A prototype of the series APF is manufactured and corresponding experiment investigation is done. The results show that when the series AP F, if adopting the hybrid control approach instead of the other two, compen sates for the voltage type harmonics-producing load, its performance can be improved greatly.