Smart Grids and Micro-Grids. Umashankar Subramaniam

is accurate with minimum convergence error compared to GS method. Similarly, the results obtained under varying irradiance and temperature conditions for PV panel such as KD245GX and Shell SP70 using GS and NR techniques are given in Tables 1.4 and 1.5, respectively. It is seen that the parameters such as A, R_se, I_LG, I_sat increases as there is increase in operating temperature of PV panel. On the flipside, the shunt resistance R_sh decreases with increasing in temperature. Similar observation is found in both the techniques, however the maximum power obtained from NR technique is higher than the GS method.

Table 1.2 Estimated values of five parameters using GS method at STC [15].

PV module	Estimated parameters at STC
	A	Rse (Ω)	Rsh (Ω)	Ilg (A)	Isat (A)
KD245GX	1.43	0.156	623.23	8.91	4.71E-07
U5-80	1.606	0.009	68.1	5.21	2.79E-06
Shell SP70	1.553	0.324	321.22	4.7	1.56E-06

Table 1.3 Estimated values of five parameters using NR method at STC.

PV module	Estimated parameters at STC
	A	Rse (Ω)	Rsh (Ω)	Ilg (A)	Isat (A)
KD245GX	1.429	0.1562	623.235	8.9122	4.67E-07
U5-80	1.6043	0.0086	66.6312	5.2107	2.76E-06
Shell SP70	1.5536	0.3242	321.2234	4.2543	1.42E-06

Table 1.4 Estimation of PV module parameters under change in irradiance and temperature using GS method [15].

PV Modules	G (W/m2)	T(°C)	A	Rse (Ω)	Rsh (Ω)	Ilg (A)	Isat (A)	Vmpp (V)	Impp (A)	Pmpp (W)
KD245GX	1000	30	1.432	0.157	621.37	8.94	8.39E-07	29.11	8.23	239.61
	1000	50	1.45	0.159	614.02	9.05	7.04E-06	26.38	8.21	216.64
	1000	70	1.483	0.16	606.84	9.15	4.62E-05	23.68	8.16	193.14
	800	25	1.449	0.125	779.04	7.13	5.89E-07	29.69	6.58	195.47
	600	25	1.47	0.094	103.87	5.35	7.89E-07	29.34	4.93	144.72
Shell SP70	1000	25	1.553	0.324	321.22	4.7	1.56E-06	16.51	4.25	70.16
	800	25	1.577	0.259	401.53	3.76	1.57E-06	16.59