HT instruments SOLAR I-V - Manual (Page 24)

I-V400 - SOLAR I-V
EN - 22
6. HOW TO OPERATE
6.1. TESTING PV SYSTEMS (ONLY SOLAR I-V)
For the sake of simplicity, further in this manual, the word “string” will be used, although
often the term “photovoltaic field” would be more correct. From the point of view of the
instrument, the management of a single string or of more parallel strings (photovoltaic field)
is identical. Furthermore, the acronym MPPT (Multiple Power Point Tracker) shall indicate
the characteristic of the DC/AC converter (inverter), capable of maximizing the DC power
which can be taken from the photovoltaic field (see the § 11.2 for further details), the
acronym PRp shall indicated the Performance ratio (evaluated on active powers).
CAUTION
 For the evaluation of the PRP only, the measurement of the DC (voltage
and current) is not strictly necessary
 Conversely it is necessary if you want to evaluate the performance of the
photovoltaic section (ndc) and DC / AC conversion (nac)
Simbol Description Unit
PRp Performance Ratio (calculated through Active power)
Irr Irradiance W/m 2
Pnom Total Nominal power of the PV section under test. kW
Tc Module Temperature °C
Te Environment Temperature °C
Pdc, Pdcx Total DC power measured, DC power of PV field x (x=1,2,3) kW
Pac, Pacx Total AC power measured, AC power of phase x (x=1,2,3,) kW
ndc DC efficiency
nac AC efficiency
Vdc, Vdcx DC Voltage, DC voltage of PV field x (x=1,2,3) V
Idc, Idcx DC current, DC current of PV field x (x=1,2,3) A
Vac, Vacx AC Voltage, AC voltage of PV field x (x=1,2,3) V
Iac, Iacx AC current, AC current of PV field x (x=1,2,3) A
Symbols description