The nonlinear loads generate harmonic currents which distorts the power quality in the distribution network, so it can be considered as a pollutant which pollutes the entire power system. To overcome problems due to harmonics, Shunt Active Power Filters are used as a solution. Shunt active power filters (SAPFs) are conventionally used to reduce current harmonics. The active harmonic filters introduce compensating currents into the source to mitigate the harmonics injected by the load current. The compensating currents will be derived by sensing three-phase voltages at the Point of Common Coupling (PCC) and load currents. The paper presents performance of Hybrid nine-level inverter based shunt active power filter for improve power quality in the distribution network. The proposed inverter is realized using a T-type neutral point-clamped inverter connected in series to a flying capacitor (FC) H-bridge. A self-voltage balancing based on superfluous switching state is developed and integrated with PWM controller, which is responsible for constrain the FC voltage at one-fourth of the input dc source voltage. This is achieved using only ten power switches (among which two are operated at line frequency). Only one FC is incorporated in the circuit for generating the 9L output voltage. Further, it is confirmed that the proposed inverter structure has improved reliability and by cascading additional FCs, it can be effortlessly extended to obtain even higher number of voltage levels. In addition, a sensor less PWM technique based on the principle of energy balance for regulating the voltage of FC is suggested Instantaneous reactive power theory (IRPT) technique is selected to extract the harmonic components and this a new hybrid nine-level inverter switching signals are generated through proposed three-level hysteresis current controller (HCC) that achieves significant reduction in the magnitude and variation of the switching frequency; it is indicating improved performance compared to 2-level HCC. The simulation results reveal that the shunt active power filter is effectively compensating the current harmonics at point of common coupling that facilitates improves power quality in the distribution network.
کلید واژگان :Shunt Active Power Filter, Instantaneous Reactive Power Theory (IRPT), T-Type Neutral Point Clamped (TNPC), Flying Capacitor (FC), Three-Level Hysteresis Current Controller (HCC), Power Quality.
ارزش ریالی : 300000 ریال
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