光伏器件第10部分:线性相关和线性测量方法

[中文适用范围]： 本部分IEC 60904描述了用于测量光伏（PV）器件的任一电参数（Y）相对于测试参数（X）的依赖关系，并确定该依赖关系接近理想线性（直线）函数的程度。它还提供了如何处理与理想线性依赖关系的偏差，以及一般来说如何处理光伏器件电参数非线性的一般指南。典型的器件参数是短路电流I SC、开路电压V OC和最大功率P max。典型的测试参数是温度T和辐照度G。然而，本文档中描述的原则可以应用于任何其他测试参数，只需对用于改变该参数本身的过程进行适当调整。光伏模块和系统的性能评估，以及从一个温度和辐照度集到另一个温度和辐照度集的性能转换，通常依赖于线性方程的使用（例如参见IEC 60891、IEC 61853-1、IEC 61829和IEC 61724-1）。本文档规定了线性依赖测试方法、数据分析以及结果接受限值的要求，以确保这些线性方程能给出令人满意的结果。此类要求还规定了温度范围，在该范围内可以使用的辐照度线性方程。本文档还给出了如何校正光伏器件的短路电流I SC相对于辐照度的理想线性依赖关系（线性）的偏差的程序，无论它们是根据9.7设定的限值被分类为线性还是非线性。对于使用太阳能模拟器以及自然阳光下的测量，都考虑了光谱辐照度分布和光谱失配的影响。此处描述测量方法适用于所有光伏器件，对于多结光伏器件需稍加注意，并旨在对稳定器件或具有相同技术的等效器件上执行，其稳定性符合IEC 61215相关部分设定的标准。这些测量旨在在所有需要线性器件或规定非线性器件限制的测量和校正程序之前进行。本文档使用的主要方法基于拟合过程，将线性（直线）函数拟合到一组测量数据点{X i ,Y i}。线性函数使用最小二乘拟合计算例程，在更先进的分析中，也考虑了测量的扩展组合不确定度（k=2）。在短路电流数据相对于辐照度的情况下，线性函数穿过原点。计算测量数据与理想线性函数的偏差，并规定了允许的百分比偏差限值。第6章（自然阳光和太阳能模拟器下的测量）、第7章（微分光谱响应测量）和第8章（通过双灯法和N灯法测量）描述了确定Y（X）依赖关系与线性（直线）函数偏差的程序。第9章给出了确定与线性函数偏差的数据分析。当器件满足特定测量依赖关系Y（X）的9.7要求时，该器件被认为是线性的。 [外文原描述]： IEC 60904-10:2020 describes the procedures used to measure the dependence of any electrical parameter (Y) of a photovoltaic (PV) device with respect to a test parameter (X) and to determine the degree at which this dependence is close to an ideal linear (straight-line) function. It also gives guidance on how to consider deviations from the ideal linear dependence and in general on how to deal with non-linearities of PV device electrical parameters. This third edition cancels and replaces the second edition published in 2009. This edition includes the following significant technical changes with respect to the previous edition: a. Modification of title. b. Inclusion of an Introduction explanatory of the changes and the reasoning behind them. c. Inclusion of a new Clause Terms and Definitions (Clause 3), with distinction between generic linear dependence and linear dependence of short-circuit current versus irradiance (linearity). d. Explicit definition of equivalent sample (Clause 4). e. Technical revision of the apparatus (Clause 5), of the measurement procedures (Clause 6 to Clause 8) and of the data analysis (Clause 9), with separation of the data analysis for a generic linear dependence from the data analysis specific to linearity (i.e. short-circuit current dependence on irradiance) assessment. Additionally, inclusion of impact of spectral effects on both linearity and linear dependence assessment. f. Introduction of specific data analysis for two-lamp method, making it fully quantitative. Addition of extended version called N-lamp method. g. Modification of the linearity assessment criterion with inclusion of a formula that can be used to correct the irradiance reading of a PV reference device for non-linearity of its short-circuit current versus irradiance. A linearity factor is specifically newly defined for this purpose. h. Revision of the requirements for the report (Clause 10) in order to improve clearness about what information is always necessary and what is dependent on the procedure actually followed to measure the linear dependence, including the type of dependence measured (generic or linearity).