Title :
Data sampling speed versus energetic measurement errors in photovoltaic system monitoring
Author :
Kurokawa, Kosuke
Author_Institution :
Electrotech. Lab., Japan
Abstract :
To measure solar irradiation and photovoltaic array output energy, measuring accuracy cannot be guaranteed unless the data sampling interval is appropriately selected. From this viewpoint, actual irradiance had been measured by comparatively high speed sampling of 1 to 4 seconds for 44 months and the daily errors of numerical integral has been estimated for various step sizes. Approximation formulae of the error versus the step size have been statistically obtained as well as their probability density function covering ±4σ. Finally a nomograph is presented to decide an appropriate sampling interval. A concluding example shows that the deviating component of the error exceeding ±1% can happen once for every 1 month or 6 months if the step size is selected as 105 seconds or 65.5 seconds, in each of which the total error becomes -0.0485±1% or -0.0336±1% including an average error component
Keywords :
data acquisition; measurement errors; measurement theory; photovoltaic power systems; power system measurement; probability; solar cell arrays; solar cells; 1 to 4 s; 105 s; 44 month; 65.5 s; PV power system monitoring; data sampling interval; error; measuring accuracy; nomograph; numerical integral; output energy measurement; photovoltaic array; probability density function; solar irradiation; step size; Energy measurement; Measurement errors; Monitoring; Photovoltaic systems; Probability density function; Sampling methods; Size measurement; Solar power generation; Time measurement; Velocity measurement;
Conference_Titel :
Photovoltaic Energy Conversion, 1994., Conference Record of the Twenty Fourth. IEEE Photovoltaic Specialists Conference - 1994, 1994 IEEE First World Conference on
Conference_Location :
Waikoloa, HI
Print_ISBN :
0-7803-1460-3
DOI :
10.1109/WCPEC.1994.520061
