Research Of Harmonic Detection And Some Parameters Design On Hybrid-shunt Active Power Filter

Power electronics technology has brought convenient, efficient and huge profitsto mankind, at the same time, its harmonics, nonlinear, shock and unbalancedelectricity characteristics have brought serious pollution to the quality of the powergrid, the grid injection of a large number of harmonics and reactive power. A largenumber of grid harmonics will bring a series of questions, such as relay protection andautomatic equipment malfunction, etc. Reactive power will increase the heat loss ofthe circuit, and also increase the capacity of the generators and transformers.Traditional harmonic suppression and reactive power compensation is passive powerfilter, but passive power filter has congenital lacks, it can’t meet requirements of usersof power. At this time active power filter came into being, the active power filter cansuppress harmonic current and compensate reactive power with real-time and dynamicnature, but its capacity is limited by switch. Though passive power filter doesn’t havereal-time and dynamic characteristics, its capacity is large. Therefore, the hybridactive power, which is a combination of active power filter and passive power filter isa best choice. Hybrid active power filter, as a device that can suppress harmonics andcompensate for reactive power, is becoming a hot topic.There are three key points in the development of hybrid active power filter, thedetection of harmonic current; control of the output of the compensation current;design of parameter of various parts, these are the focus of research of hybrid activepower filter. In order to quickly and effectively detect the harmonics generated bynonlinear loads, the paper applys a harmonic real-time detection method based on theFBD used in the hybrid active power filter, compared to the detection method basedon instantaneous reactive power theory, the method based on FBD has no complexpark and d-q transformation, it can be used to detect the fundamental and harmoniccurrent real-time for single-phase, three-phase, and three-phase four-wire system; Inorder to improve control accuracy and enhance the robustness of the control system,the space vector voltage control strategy is more mature technology which is used tocontrol the compensation current; When the hybrid active power is designed,thedesign principles of various parts are discussed in detail. At last, the simulation modelwas established in MATLAB according to proposed detector and control strategies,the simulation results showed the correctness of the detection and effectiveness of the control strategy.