Losses Calculation And Efficiency Optimization Of Photovoltaic Reactor

Photo-Voltaic Reactor(PVR)is one of the key components in photovoltaic generating system(PVGS).It plays an important role to reduce high frequency harmonics,improve power quality,and ensure the reliability of PVGS.Its efficiency influences on the whole efficiency of PVGS.Therefore,one focuses on minimizing losses of PVR.Different from normal reactors,PVRs are required for much more reliability.Because of the complexity of leakage magnetic field,hot spots,which influence the PVR's life,may occur in coil endings,iron core,and structural components.Precision calculation of losses is the fundamental of further efficiency optimization.Core loss calculation has been research difficulty.The precission is not satisfied by traditional formula used in finite element method(FEM)to fit the experimental loss curve.As a result,an eddy current loss extraction method is proposed in this paper in order to fit the hysteresis loss of iron core.Phase current waveforms of PVR are obtained by using MATLAB/SIMULINK platform and their amplitudes and phases are calculated by fast Fourier transformation(FFT).These data are fundamentals for losses calculation of PVR.The formula of eddy current loss is derived from infinite thin plate according to harmonic electromagnetic field.Then hysteresis loss curves are fitted by extracting eddy current loss from experimental iron loss curves.These theoretical formular can be used to estimate the iron losses of PVR.In addition,losses of PVR are calculated by FEM based on ANSYS MAXWELL software.Furthermore,air gap structures and sectional sizes of iron core are detailed analysis to find their influences on coil losses.Various measures including electromagnetic shield are taken to reduce stray loss of structural plates and to avoid local hotspots in coil endings,iron core and auxiliary components,thus optimization design method is concluded to raise the efficiency of PVR by adjusting the sizes of its structure and adding shields.According to the aforementioned results,combination method is adopted to optimize the inverter side reactor.It is proved to be more efficient than the original reactor.