-This paper presents an algorithm of a compensation of the grid current distortion caused by the grid voltage unbalance and distortion in 3-phase bi-directional DC to AC inverter. Usually 3-phase grid system has unbalance and distortion because of connecting 1-phase and non-linear load with 3-phase load using same input node. Controlling 3-phase inverter by general method under the unbalanced and distorted grid voltage, the grid current has distortion. This distortion of the grid current cause the grid voltage distortion again. So, it need to control the grid current balanced and non-distorted, even the grid voltage gets unbalanced and distorted. There are some complex method to compensate the gird current distortion. it suggest simple method to solve the problem. Simulation and experiment is used to validate the proposed algorithm.
Fuel cell power system is one of the most promising energy source for the alternative energy because it has unique advantages such as high energy density, no power drop during operation, and feasible to make compact size. However, due to very low response time, fuel cell is difficult to correspond to drastic load changes and start-up operation. For solving these problem, fuel cell power system must include energy storage device such as Li-Poly battery or super capacitor. Therefore, bi-directional DC-DC converter must be required for this storage device and fuel cell-PCS control. This paper presents a design and modeling of the bi-directional DC/DC converter. Firstly, we present modeling the boost and buck mode of the bi-directional converter through both PWM switch model and state space averaging technique. Secondly, in order to minimize output ripple and transient response overshoot, we have two identical DC-DC converters interleaved and adopt two-loop voltage-current controller. The proposed bi-directional DC-DC converter's modeling method and control design have been verified with computer simulation and experimentation.
td a t e:2 0 1 3 .1 1 .4 . ,J u d g me n td a t e:2 0 1 3 .1 1 .4 . ,P u b l i c a t i o nd e c i d ed a t e:2 0 1 3 .1 2 .2 2 . ) Abstract:Th i sp a p e rp r o p o s e sDCo f f s e tc u r r e n tc o mp e n s a t i o nme t h o do ft r a n s f o r me r l e s sf u e l c e l l /P V P C S . DCo f f s e t c u r r e n ti sg e n e r a t e db yt h eu n b a l a n c e di n t e r n a lr e s i s t a n c eo ft h es wi t c h i n gd e v i c e si nf u l lb r i d g et o p o l o g y . Th eo t h e r c a u s ei st h es e n s i t i v i t yo ft h ec u r r e n ts e n s o r , wh i c hi sl o we rt h a nDS Pi nr e s o l u t i o n .I fp o we rc o n v e r t e rs y s t e m h a s t h e s ec a u s e s , t h eACo u t p u tc u r r e n ti nt h ei n v e r t e rwi l l g e n e r a t et h eDCo f f s e t . I nc a s eo ft r a n s f o r me r l e s sg r i d -c o n n e c t e d i n v e r t e rs y s t e m,DC o f f s e tc u r r e n ti sf a t a lt og r i d -s i d e , wh i c hr e s u l t si ns a t u r a t i n gg r i ds i d et r a n s f o r me r . S e v e r a ls i mu l a t i o n r e s u l t ss h o w t h ed i f f i c u l t i e so fd e t e c t i n g DC o f f s e tc u r r e n t .De t e c t i n g DC o f f s e tc u r r e n t me t h o dc o n s i s t so ft h ed i f f e r e n t i a l a mp l i f i e r sa n dP WM i sc o mp e n s a t e db yt h eo u t p u to ft h eOpa mpc i r c u i twi t h i n t e g r a t o rc o n t r o l l e r . P S I M s i mu l a t i o nv e r i f i e st h a tt h ep r o p o s e dme t h o di ss i mp l e ra n dmo r ee f f e c t i v et h a nu s i n g l o w r e s o l u t i o nc u r r e n ts e n s o ra l o n e .Key Words:직류분( DC o f f s e t ) , 인버터( I n v e r t e r ) , 무변압기형( Tr a n s f o r me r l e s s ) , 태양광( P h o t oVo l t a i c ) , 연료전지( F u e lC e l l )
As a worldwide trend, the spatial information that is established by country, institution and purpose is integrated into the data with a single spatial reference to improve the data connectivity and usability. In this study, a new national single origin plane rectangular coordinate system was studied to efficiently respond to the changes in the spatial reference according to the introduction of a new national geodetic standard and to the demand of seamless data service in the spatial information sector. For this purpose, the Korean Peninsula was set as the projection region and the projection distortion in the projection region was analyzed. The projection parameters were defined to homogenize and minimize the projection distortion, and their standardization and registration on the international organizations were conducted. The study on the required optimal projection equation resulted in the Hooijberg projection equation and projection parameters (φ λ , φ λ , Κ, Ν, Ε) resulted in 38° N and 128° E projection origin, and a scale factor of 0.99924. The proper false northing and easting were 700,000m N and 400,000m E, respectively, considering the introduction of country station index system. This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http:// creativecommons.org/licenses/by-nc/3.0) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.
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