Double-Band hysteresis current control method for three-phase shunt active power filters

ABSTRACT: The widespread use of nonlinear loads in all branches of industry and in the power electronic equipment has increased the harmonic current distortion on the power system which leads to poor power factor, increased heating losses, and harmful disturbance to other loads connected at the same point of common coupling (PCC). For harmonic elimination and improving the power factor, passive LC filters have conventionally been used although, they have many drawbacks. Alternatively, shunt active power filters (APFs) have been considered as a potential candidate. In recent publications, diverse control strategies have been introduced for three-phase APFs. Among the current-control strategies, the conventional single-band hysteresis current-control (SBHCC) has received much attention due to its major advantages such as higher accuracy, fast dynamic response, robustness and simplicity in implementation. Despite these advantages, the SBHCC has a major disadvantage that the switching frequency is very high which increases the switching losses. These losses can be decreased by increasing the hysteresis band, at the expense of decreasing the switching frequency. In this thesis, a double-band hysteresis current-control (DBHCC) scheme is introduced for three-phase shunt active filters. First, the mathematical modeling of the three-phase APF is developed. Then, it is implemented by using SIMULINK/MATLAB. Finally, the results are compared with that of obtained by the SBHCC method. Keywords: Active Power Filter, Power Electronics, Hysteresis Current Control Method. …………………………………………………………………………………………………………………………