IEC 61724:1998 pdf download – Photovoltaic system performance monitoring -Guidelines for measurement, data exchange and analysis

IEC 61724:1998 pdf download – Photovoltaic system performance monitoring -Guidelines for measurement, data exchange and analysis.
IEC 61724 recommends procedures for the monitoring of energy-related PV system characteristics such as in-plane irradiance, array output. storage input and output and power conditioner Input and output: and for the exchange and analysis of monitored data. The purpose of these procedures is to assess the overall performance of PV systems configured as stand-alone or utility grid-connected, or as hybridised with rion-PV power sources such as engine generators and wind turbines,
This standard may not be applicable to small stand-alone systems due to the relatively high cost of the measurement equipment.
2 Normative references
The following normative documents contain provisions which, through reference In this text. constitute provisions of this International Standard. At the time of publication, the editions indicated were valid. All normative documents are subject to revision, and parties to agreements based on this International Standard are encouraged to investigate the possibility of applying the most recent editions of the normative documents indicated below. Members of lEG and ISO maintain registers of currently valid International Standards.
lEG 60904-2:1969, Photovoltaic devices — Part 2: Requirements for reference solar cells Amendment 1 (1998)
IEC 60904-6:1994, Photovoltaic devices — Part 6: Requirements for reference solar modules Amendment 1(1998)
lEG 61194:1992, Characteristic parameters of stand-alone photovoltaic (PV) systems
lEG 61829:1995, Crystalline silicon photovoltaic (PV) array — On-site measurement of
I-V characteristics
3 Measured parameters
Parameters to be measured are shown In table I and figure 1. Other parameters can be calculated from the measured data in real time by the data acquisition system’s software. Note that all blocks In figure 1 can represent multiple components. The measured parameters and array characteristics are defined in IEC 61194.
The parasitic power drawn by all ancillary systems shall be considered a power loss of the PV plant and shall not be considered a load. All monitoring systems not essential for the operation of the PV plant shall be considered part of the load. The monitoring equipment may present a malor part of the overall power consumption, and the end user should be made aware that supplemental power may be required to satisfy the total load requirement.
4 Monitoring method
4.1 Measurement of Irradlance
lrradance data are recorded in the plane of the array for use in the performance analysis of the PV system. Horizontal data may also be recorded to permit comparisons with standard meteorological data from other locations.
In-plane irradiance shall be measured in the same plane as the pliotovottaic array by means of calibrated reference devices or pyranometers. If used, reference cells or modules shall be calibrated and maintained In accordance with IEC 609042 or IEC 609046. The location of these sensors shall be representative of the irradiance conditions of the array- The accuracy of irradiance sensors, including signal conditioning, shall be better than 5 % of the reading.
4.2 Measurement of ambient air temperature
Ambient air temperature shall be measured at a location which is representative of the array conditions, by means of temperature sensors located In solar radiation shields. The accuracy of air temperature sensors, including signal conditioning, shall be better than I K.
4.3 Measurement of wind speed
Where applicable, wind speed shall be measured at a height and location which are representative of the array conditions. The accuracy of the wind speed sensors shall be better than 0,5 ms’ for wind speeds > 5 ms, and better than 10 % of the reading for wind speeds greater than 5 m•s.