Research Of The Series Hybrid Active Power Filter Based On Fundamental Magnetic Flux Compensation Technology

As the modern power electronic technology is developing with the increase of harmonic pollution in electric power system,a lot of research on active power filter is carried out like a raging fire in order to improve the power quality.The traditional active filter uses the inverter to produces the current which is contrary to the harmonic current.So it need to control the inverter to tracking the harmonic current but it’s very difficult.Different from the traditional active filter, the series hybrid active power filter with the fundamental magnetic flux compensation only need to control the inverter to track the fundamental current and it’s very easy.This paper studied the working principle of the series hybrid active power filter with the fundamental magnetic flux compensation,set up the mathematical model based on the current control circuit,and analyses the influence of each parameter of the current control circuit to filter effect by simulink.This paper uses a switched capacitor filter to design a fundamental detection circuit and its phase shift circuit for the fundamental detection.Simulation shows that the fundamental detection effect is good.The author compares the advantages and disadvantages of several frequently-used current control methods,and focuses on two current control methods-the hysteresis current control and the triangle wave current control.Through theoretical analysis and simulation results show that the hysteresis current control method, the tracking error is small, fast response speed, but the switching frequency is not fixed; the switching frequency of the triangular wave comparison control is fixed,equal to the frequency of the triangular wave, and the tracking precision is higher, but the system robustness and response rate are not as good as hysteresis control method.At the end of this paper,it introduces an active filter with low self inductance series transformer.For the routine active filter,the load power will stop working when the active filter circuit break down.But the new filter can quit the operation when the active filter circuit break down and limit the short-circuit current when load short circuit.Simulation shows it is working well.The series hybrid active power filter with the fundamental magnetic flux compensation is different from the routine active filter.It has both advantages and disadvantages,and need more research to make it better.