# pvl_huld_parameter_estimation

PVL_HULD_PARAMETER_ESTIMATION estimates parameters for the Huld module performance model

## Contents

- Syntax
- Description
- Inputs
- Output
- Example
- Reference

## Syntax

`Model = pvl_huld_parameter_estimation(Pmp, Ee, Tm)`

## Description

`pvl_huld_parameter_estimation` returns parameters for the Huld module performance model [1]. The estimation uses robust regression to fit the Huld model, a polynomial in Tm and log(Ee), to Pmp.

## Inputs

- `Pmp` - a N x 1 vector of power (W) at the maximum power point.
- `Ee` - a N x 1 vector of effective irradiance (suns).
- `Tm` - a N x 1 vector of module (not cell) temperature (C).

## Output

- `Model` - a structure containing the model parameters:
- `Model.Pmp0` - estimated Pmp at STC.
- `Model.k` - a vector of length 6 containing the coefficients k1 through k6.

## Example

    clearvars

    % load IV curve data for a 36 cell Mitsubishi cSi module
    load 'Desoto_demo.mat'

    % Extract Pmp, Ee, and Tm data.  Actual data give cell temperature Tc, not
    % Tm, but here we'll use Tc as if it is Tm to illustrate the parameter estimation.

    Ee = [IVCurves.Ee]'/1000;
    Tm = [IVCurves.Tc]';
    Pmp = [IVCurves.Imp]'.*[IVCurves.Vmp]';

    Model = pvl_huld_parameter_estimation(Pmp, Ee, Tm);

    pPmp = pvl_huld(Model,Ee,Tm);

    figure
    plot(Ee*1000,Pmp,'x')
    hold all
    plot(Ee*1000,pPmp,'.')
    xlabel('POA irradiance (W/m^2)');
    ylabel('Power (W)')

## Reference

[1] A power-rating model for crystalline silicon PV modules, T. Huld, G. Friesen, A. Skoczek, R. Kenny, T. Sample, M. Field, E. Dunlop, Solar Energy Materials and Solar Cells 95(2011), pp 3359-3369.