Enhancing grid stability by maintaining power quality in distribution network using FOPID and ANN controlled shunt active filter

In our everyday life we are confronting power quality issues due to primary importance of employing power electronic devices in power system network and by extensive practice of enforcing distributed generation in distribution network. Further, the key invention of electric vehicles will reduce the carbon emission to the environment. These electric vehicles need charging stations which get energy either from grid or through renewable sources. If a greater number of electric vehicles are to be charged by grid, then it gets overloaded which lead to poor power quality. Apart from this aspect presence of line inductor, capacitor and shunt capacitor equipped at consumer premises may lead to harmonic magnification in power network which ensue in voltage deformation. Because of this technological revolution harmonic is infused into the distribution network which leads to instability of grid connected system. In mere future harmonic penalty may be imposed on the end clients similar to that of maximum demand limits. So, it is very important for a consumer to avoid harmonic injection in his appliances. In existing method, passive filters are introduced to reduce the level of harmonics in the system. But it leads to resonance problem when overloaded. Thus, the main objective of this research work is to furnish the customer with quality power by diminishing the harmonic penetration throughout the power distribution using shunt active filter. To accomplish this a 10-bus radial distribution system is considered here. This system is associated with a single source and supplying nonlinear loads at bus terminus 5 and 9. The harmonic penetration is eliminated by connecting shunt active filter at the buses. The total harmonic distortion is analyzed at bus terminus 5,9 with and without active filter using MATLAB/Simulink. The simulation is carried out for both open- and closed-loop systems. A FOPID and ANN controllers are employed in closed-loop control system. The output voltage, THD, real and reactive power are measured at 5th and 9th bus. Since the distortion level increases with distance from source, the performance of controllers is examined at 9th bus. Also, the total voltage distortion in closed-loop system should comply with IEEE 519. It is well proved that as per IEEE 519 - 2014 both the controllers have the ability to manage voltage distortions within permissible limits. From the simulation results it is demonstrated that the ANN controller can eradicate harmonic injection in the radial network than FOPID controller. The THD observed in ANN controlled unit at bus 9 is 2.34, whereas it is 3.3 in FOPID controlled unit. This in turn improves the power quality of proposed network.