Design Of Active Power Filter Based On FPGA

The electrical power as a kind of energy has been widely used in society, and thepower quality has an important influence on social production and people’s life. Due tothe widespread use of various non-linear power electronic equipments, the power gridhas been caused serious harmonic pollution. At the same time, along with thedevelopment of modern digital technology, the electrical equipment is more sensitive tothe interference and abnormity of the power grid. ON one hand, the power systemharmonic pollution is worsening with the increase in the number and capacity of thenon-linear load; on the other hand, the requirements of the electricity side to the powerquality are improving. So it is very meaningful to develop active power filter which caneffectively improve power quality. This paper describes a control system design ofactive power filter based on FPGA+Cortex-M3.From the beginning, this paper introduces the topology of the active power filter,the harmonic current detection algorithm and the compensation control method.Followed by the consideration on the real situation and practicality aspects, the designof shunt active power filter based on instantaneous reactive power theory and thetriangular-wave current control mode is determined. In orderto ensurethat the system isable to fast-track and compensate the grid harmonic current, the design of instantaneousreactive power algorithm and triangle wave compensation control method can berealized in the FPGA. And the FPGA control system mainly contains the AD controlinterface, Clark transform, digital low-pass filter, sine and cosine function, Clarkinverse transformand triangular wave module.In the system design stage, the PSIM power simulation software was used toestablish the model of the shunt active power filter, which includes the main circuitstructures and implementation of instantaneous power algorithm. Followed by thedetermination of the main circuit parameters and the effect of compensation aftersimulation, which combine verify the feasibility of the algorithm. In addition, somedevelopment functions, such as the man-machine interface, fault records, key control,serial communications and Ethernet communication, etc., are realized in the processor of Cortex-M3core. There is a good simulation effect for the active power filter torealize the function of tracking and compensate the grid harmonic current fastly andaccurately.