09-11-2016, 04:18 PM
Design & Analysis of ANFIS for Power quality enhancement using Hybrid Filter Plug in Vehicle
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Abstract: The main objective of this paper is the mitigation of current harmonics and the protection of point of common coupling from voltage distortions. Power quality issues related to plug in vehicles and focuses on improving electric vehicle load connection to the grid. While protecting the sensitive loads from voltage sags and swells ridded of the series transformer. A transformer less hybrid series active filter with ANFIS controller is proposed to enhance the power quality in single phase systems with critical loads. By controlling these control strategy which will present current harmonic distortion of nonlinear loads to flow in the utility side and corrects the power factor. ANFIS controller which will reduce the current harmonics and control implementation in simple, fast dynamic response and insensitive to load parameters. MATLAB/SIMULINK simulation results show the effectiveness of the proposed model.
Key words: Current harmonics, Power quality, Electric vehicle, Hybrid series active filter, ANFIS controller.
1. INTRODUCTION
The estimation of future Smart Grids associated with electric vehicle charging stations has created a severe concern on all aspects of power quality of the power system,while widespread electric vehicle battery charging units [1],[2] have detrimental effects on harmonic voltage levels [3]. On the other hand, the development of harmonics fed from nonlinear loads like electric vehicle propulsion battery chargers [4],[5],which indeed have detrimental impacts on the power system and affect plant equipment, should be considered in the development of modern grids. The increased level of distortions in current which will increase the heating losses and cause the failure of
electric equipment so the system efficiency will be reduced [6].
Now a days the usage of power electronic devices increases the current and voltage harmonics generated causing harmonic distortion which will decrease the power quality. Due to harmonic distortion so many problems are occur which are increased heat losses, life span reduction of transformer, operation problems on protecting relays,
Circuit breakers and fuses. The solution of reducing the total harmonic distortion is by using filters are the best. There are two types of active power devices which are shunt and series active filters including hybrid ones. In these the first category includes the series active filters including hybrid type. In these series active filters are used due to more advantages compared to shunt active filters. Series active filters (SeAFs) are less scattered than shunt type filters [7].There are so many advantage compared to series type filters than shunt type. The second category of these filters is developed for the voltage issues on sensitive loads.
The hybrid series active filter are capable to mitigate current harmonics, thus ensures the power factor correction and eliminates the distortions of voltage at PCC [8] . The three-phase SeAFs are well research works are reported but single phase applications of SeAFs has limited research work in the literature. In this paper, a single-phase transformerless HSeAF is proposed and capable of cleaning up the grid-side connection bus bar from current harmonics generated by a nonlinear load
. SYSTEM ARCHITECTURE
a) System configuration
The transformerless hybrid series active filter electrical diagram is shown in fig.2 which is composed of an H-bridge and passive filter. H-bridge is the electronic circuit which enables a voltage to be applied across the load in any direction. H-bridge is connected in between the source and the load. A passive capacitor which ensures low impedance path for harmonics in current. A dc auxillary source could be connected to inject power during voltage drop.
The system is implemented for a rated power of 2.2kVA.The system configuration parameters are shown in Table 1.A source voltage of 120Vrms is connected to a 1100 VA nonlinear load and a 998 VA linear load with a power factor of 0.46.The THSeAF is connected in series to inject the compensation of voltage. On the dc side of the compensator the auxiliary dc-link energy storage system is installed. HSeAF are used to compensate distortions of the current type of nonlinear loads.
The THSeAF is avoided , the current harmonics flowed directly into the grid. As one can perceive, even during normal operation, the THD for current harmonics 4.4% distort the PCC, resulting in a voltage THD of 0.44%.The behavior of the system when the grid is highly polluted with 4.4% of THD is instanced. The proposed configuration could be solely connected to the grid with no need of a bulky and costly series injection transformer, making this topology capable of compensating source current harmonics and voltage distortion at the PCC. Even if the number of switches has increased, the transformer less configuration is more cost-effective than any other series compensators, which generally uses a transformer to inject the compensation voltage to the power grid. The optimized passive filter is composed of 5th, 7th, and high pass filters.