Research Article

Data-Driven Photovoltaic System Modeling Based on Nonlinear System Identification

Table 2

Best fit with different input and output nonlinearity.

Hammerstein-Wiener model
Input nonlinearityOutput nonlinearityFinal predicted error (FPE)Loss functionBest fit (%)

Piecewise linearPiecewise linear6.7236.72380.25
Piecewise linearSigmoid network5.0365.03686.11
Piecewise linearSaturation1.7511.75192.83
Piecewise linearDead zone1.0231.02392.24
Piecewise linearWavelet network2.0832.08288.11
Sigmoid networkPiecewise linear1.2651.26577.94
Sigmoid networkSigmoid network3.5473.54781.05
Sigmoid networkSaturation2.0162.01689.45
Sigmoid networkDead zone4.9524.95185.37
Sigmoid networkWavelet network0.16940.169363.09
SaturationPiecewise linear1.2621.26292.22
SaturationSigmoid network1.1991.19992.44
SaturationSaturationFEFEFE
SaturationDead zoneFEFEFE
SaturationWavelet network0.76060.760185.83
Dead zonePiecewise linear0.39740.397493.4
Dead zoneSigmoid network1.4641.46493.98
Dead zoneSaturationFEFEFE
Dead zoneDead zoneFEFEFE
Dead zoneWavelet network0.29720.297290.86
Wavelet networkPiecewise linear1.7171.71691.42
Wavelet networkSigmoid network2.0382.03789.61
Wavelet networkSaturation131.5131.5āˆ’0.7279
Wavelet networkDead zone2.0542.05490.09
Wavelet networkWavelet network0.36430.36493.81

FE: failed estimation.