Reivindicaciones
1. A method for estimating equivalent temperature in photovoltaic modules that comprises: - performing, simultaneously and at random test conditions, the following measurements: ∘ current intensity vs. voltage curve of a reference photovoltaic module (1), of which the current intensity vs. voltage curve thereof is known at standard test conditions; ∘ current intensity vs. voltage curve of at least one first test photovoltaic module (2), from which the electrical characteristics thereof at standard test conditions are to be obtained; ∘ temperature of a specific area of the reference photovoltaic module (1) and of the at least one first test photovoltaic module (2); - estimating the equivalent temperature of the reference photovoltaic module (1) by means of the following expression: T eq , R = T eq , R ∗ + V 0 R V 0 R ∗ − 1 × β − 1 <img class="EMIRef" id="688725024-ib0013" /> wherein Teq,R is the equivalent temperature of the reference photovoltaic module (1) at the mentioned random test conditions; T eq , R ∗ <img class="EMIRef" id="688725024-ib0014" /> is the equivalent temperature of the reference photovoltaic module (1) at standard test conditions; V0 R is the open-circuit voltage of the reference photovoltaic module (1) obtained from the current intensity vs. voltage curve at the mentioned random test conditions; V 0 R ∗ <img class="EMIRef" id="688725024-ib0015" /> is the open-circuit voltage of the reference photovoltaic module (1) obtained from the current intensity vs. voltage curve at standard test conditions; β is a predetermined temperature coefficient of the reference photovoltaic module (1); characterized in that it comprises - estimating the equivalent temperature of the at least one first test photovoltaic module (2) by means of the following expression: T eq , C = T eq , R + T Z , C − T Z , R <img class="EMIRef" id="688725024-ib0016" /> wherein Teq,C is the equivalent temperature of the at least one first test photovoltaic module (2) at the mentioned random test conditions; TZ,C is the measured temperature of a specific area of the at least one first test photovoltaic module (2); TZ,R is the measured temperature of a specific area of the reference photovoltaic module (1). 2. The method for estimating equivalent temperature in photovoltaic modules according to claim 1, wherein it comprises using at least one infrared-pointer temperature sensor to measure the temperature of a specific area of the reference photovoltaic module (1) and of the at least one first test photovoltaic module (2). 3. The method for estimating equivalent temperature in photovoltaic modules according to claim 2, wherein it comprises focusing, respectively, each of the infrared pointers on the centre of the back face of each photovoltaic module. 4. The method for estimating equivalent temperature in photovoltaic modules according to any of the preceding claims, wherein the specific area of the reference photovoltaic module (1) and of the at least one first test photovoltaic module (2) where the temperature is measured, is an area of said photovoltaic modules that is accessible and free of obstacles in a permanent work location of said modules. 5. The method for estimating equivalent temperature in photovoltaic modules according to any of the preceding claims, wherein it comprises associating an effective solar irradiance with the estimated equivalent temperatures of the reference photovoltaic module (1) and of the at least one first test photovoltaic module (2), wherein said effective solar irradiance is calculated starting from the current intensity vs. voltage curve of the reference photovoltaic module (1) at the mentioned random test conditions, and depending on the current intensity vs. voltage curve of the reference photovoltaic module (1) at standard test conditions, by means of the following expression: G = G ∗ × I SC , R I SC , R ∗ <img class="EMIRef" id="688725024-ib0017" /> wherein G is the effective solar irradiance to be associated with the estimated equivalent temperatures of the reference photovoltaic module (1) and of the at least one first test photovoltaic module (2); G* is the effective solar irradiance associated with the standard test conditions; I SC , R ∗ <img class="EMIRef" id="688725024-ib0018" /> is the short-circuit current intensity of the reference photovoltaic module (1) obtained from the current intensity vs. voltage curve at standard test conditions; ISC,R is the short-circuit current intensity of the reference photovoltaic module (1) obtained from the current intensity vs. voltage curve at the mentioned random test conditions. 6. A device (4) for estimating equivalent temperature in photovoltaic modules characterised in that it comprises: - a first set of equipment for tracing current intensity vs. voltage curves, configured to measure the current intensity vs. voltage curve of a reference photovoltaic module (1) at random test conditions; - at least one second set of equipment for tracing current intensity vs. voltage curves, configured to measure the current intensity vs. voltage curve of at least one first test photovoltaic module (2) at random test conditions; - a first device for measuring temperature, configured to measure a temperature in an area of the reference photovoltaic module (1); - at least one second device for measuring temperature, configured to measure a temperature in an area of the at least one first test photovoltaic module (2); - synchronisation means of the modules for registering current intensity vs. voltage curves, and; - processing means configured to estimate the equivalent temperature of the reference photovoltaic module (1) and of the at least one first test photovoltaic module (2) at the mentioned random test conditions. 7. The device for estimating equivalent temperature in photovoltaic modules according to claim 5, wherein at least one of the modules for measuring temperature is an infrared-pointer temperature sensor. 8. The device for estimating equivalent temperature in photovoltaic modules according to any of claims 6 or 7, wherein the modules for registering current intensity vs. voltage curves are capacitive loads. 9. The device for estimating equivalent temperature in photovoltaic modules according to any of claims 6 to 8, wherein the synchronisation means comprise a button, configured to send a simultaneous firing signal to the sets of equipment for tracing current intensity vs. voltage curves. 10. The device for estimating equivalent temperature in photovoltaic modules according to any of claims 6 to 9, wherein the processing means are configured to estimate the equivalent temperature of the reference photovoltaic module (1), by means of the following expression: T eq , R = T eq , R ∗ + V 0 R V 0 R ∗ − 1 × β − 1 <img class="EMIRef" id="688725024-ib0019" /> wherein Teq,R is the equivalent temperature of the reference photovoltaic module at the mentioned random test conditions; T eq , R ∗ <img class="EMIRef" id="688725024-ib0020" /> is the equivalent temperature of the reference photovoltaic module at standard test conditions (typically 25 °C); V0 R is the open-circuit voltage of the reference photovoltaic module obtained from the current intensity vs. voltage curve at the mentioned random test conditions; V 0 R ∗ <img class="EMIRef" id="688725024-ib0021" /> is the open-circuit voltage of the reference photovoltaic module obtained from the current intensity vs. voltage curve at standard test conditions; β is a predetermined temperature coefficient of the reference photovoltaic module (1); and wherein the processing means are configured to estimate the equivalent temperature of the at least one first test photovoltaic module (2) by means of the following expression: T eq , C = T eq , R + T Z , C − T Z , R <img class="EMIRef" id="688725024-ib0022" /> wherein Teq,C is the equivalent temperature of the at least one first test photovoltaic module at the mentioned random test conditions; TZ,C is the temperature measured from a specific area of the at least one first test photovoltaic module (2); TZ,R is the temperature measured from a specific area of the reference photovoltaic module (1). 11. The device for estimating equivalent temperature in photovoltaic modules according to any of claims 6 to 10, wherein the processing means are configured to calculate an effective solar irradiance value associated with the estimated equivalent temperatures of the reference photovoltaic module (1) and of the at least one first test photovoltaic module (2), wherein said calculation is made by means of the following expression: G = G ∗ × I SC , R I SC , R ∗ <img class="EMIRef" id="688725024-ib0023" /> wherein G is the effective solar irradiance to be associated with the estimated equivalent temperatures of the reference photovoltaic module (1) and of the at least one first test photovoltaic module (2); G* is the effective solar irradiance associated with the standard test conditions; I SC , R ∗ <img class="EMIRef" id="688725024-ib0024" /> is the short-circuit current intensity of the reference photovoltaic module (1) obtained from the current intensity vs. voltage curve at standard test conditions; ISC,R is the short-circuit current intensity of the reference photovoltaic module (1) obtained from the current intensity vs. voltage curve at the mentioned random test conditions. 12. The device for estimating equivalent temperature in photovoltaic modules according to any of claims 6 to 11, wherein the processing means are configured to calculate the electrical characteristics of the at least one first test photovoltaic module (2) at standard test conditions, starting from the current intensity vs. voltage curve of said first test photovoltaic module (2) at the mentioned random test conditions and starting from the estimated equivalent temperature of said at least one first test photovoltaic module (2) at the mentioned random test conditions, wherein said calculation is made by means of the following expression: P M , C ∗ = P M , C P M , R × P M , R ∗ × 1 + γ × T eq , R − T eq , R ∗ 1 + γ × T eq , C − T eq , C ∗ <img class="EMIRef" id="688725024-ib0025" /> wherein P M ∗ <img class="EMIRef" id="688725024-ib0026" /> is the maximum power delivered by the photovoltaic module at standard test conditions; wherein "M" indicates maximum and "*" indicates standard test conditions; and wherein the subscripts "C" and "R" indicate, respectively, the at least one first test photovoltaic module (2) and the reference photovoltaic module (1); wherein T eq , R ∗ = T eq , C ∗ , <img class="EMIRef" id="688725024-ib0027" /> which is equal to the temperature at the standard test conditions, and wherein the gamma coefficient "γ" is the coefficient of variation of the power of the photovoltaic module with the temperature. 13. The device for estimating equivalent temperature in photovoltaic modules according to claims 11 and 12, wherein the processing means are configured to calculate the electrical characteristics of the at least one first test photovoltaic module (2) at standard test conditions, being based on the effective solar irradiance value associated with the estimated equivalent temperature of the test photovoltaic module (2).
