Classifications

• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02S—GENERATION OF ELECTRIC POWER BY CONVERSION OF INFRARED RADIATION, VISIBLE LIGHT OR ULTRAVIOLET LIGHT, e.g. USING PHOTOVOLTAIC [PV] MODULES
  • H02S50/00—Monitoring or testing of PV systems, e.g. load balancing or fault identification
• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02S—GENERATION OF ELECTRIC POWER BY CONVERSION OF INFRARED RADIATION, VISIBLE LIGHT OR ULTRAVIOLET LIGHT, e.g. USING PHOTOVOLTAIC [PV] MODULES
  • H02S50/00—Monitoring or testing of PV systems, e.g. load balancing or fault identification
  • H02S50/10—Testing of PV devices, e.g. of PV modules or single PV cells
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
  • Y02E10/00—Energy generation through renewable energy sources
  • Y02E10/50—Photovoltaic [PV] energy

Definitions

• a photovoltaic power plant generally comprises several chains of photovoltaic modules (also called photovoltaic panels or solar panels) connected in parallel.
• each photovoltaic module in a chain must be monitored regularly in order to identify any faults that could cause a loss of production.
• the defect may be of different natures, in particular permanent if it is a hardware problem, or temporary if it is for example the presence of shading or dust on the photovoltaic module.
• the step of acquiring environmental parameters includes a step of measuring said parameters.
• the step of determining the corrected environmental parameters is implemented by solving a nonlinear optimization problem defined by the following constraints:
• Tamb c (i) is the corrected ambient temperature for group i of photovoltaic modules
• WindSpeed c (C) is the corrected wind speed for group i of photovoltaic modules
• Pmppt( ⁇ ) corresponds to the power delivered by group i of photovoltaic modules at the maximum power point
• Pelec c ( i , j ) corresponds to the corrected electric power of each photovoltaic module of the group i of photovoltaic modules
• Modules Ref (i) corresponds to the reference photovoltaic module(s) present in group i of photovoltaic modules;
• ⁇ is a power loss factor as a function of temperature
• P STC (W) is a reference electrical power delivered by a photovoltaic module under standard operating conditions
• the method comprises steps of: Determining the current at the maximum power point which passes through the group i of photovoltaic modules and the voltage at the maximum power point at the terminals of the group i of photovoltaic modules, Determination of the voltage at the terminals of each photovoltaic module of the group i of photovoltaic modules,
• the method includes a step for carrying out diagnostics and/or maintenance of the target photovoltaic module when said determined electrical power loss is greater than said threshold value.
• a module for acquiring the following environmental parameters for group i of photovoltaic modules o Gh (W/m2): global irradiance at the horizontal level; o Tamb (°C): Ambient temperature; o WindSpeed (m/s): Wind speed;
• the system includes means for measuring environmental parameters.
• the system comprises a module for determining a temperature of each photovoltaic module, which is configured to determine the temperature of each photovoltaic module of the group i of photovoltaic modules from a thermal image acquired for each photovoltaic module of group i of modules.
• the module for determining the corrected environmental parameters is configured to solve a nonlinear optimization problem defined by the following constraints:
• Pmppt( ⁇ ) corresponds to the power delivered for group i of photovoltaic modules at the maximum power point
• the system comprises:
• AP corresponds to an accepted power tolerance for each photovoltaic module of the group i of photovoltaic modules
• FIG. 1 schematically represents a conventional photovoltaic power plant
• FIG. 4 shows the different steps of the method of the invention and the different functional software modules involved during the execution of this method; Detailed description of at least one embodiment
• Control means integrated or not in the converter, are able to control the inverter to perform the voltage conversion.
• each photovoltaic module is referenced j, with j ranging from 1 to M.
• Each photovoltaic module Mi ,j has a thermal image denoted Irrii j.
• the system of the invention is intended to estimate, ultimately, the loss of production or energy power of a photovoltaic module that is defective in operation.
• the estimate can be made when the photovoltaic plant is in operation.
• in operation or “during operation”, it is meant that the photovoltaic module or the photovoltaic power plant is in the process of producing electrical energy, by conversion of incident light energy.
• the estimation system comprises the following elements:
• the computer 5 is intended to estimate the electric power of a photovoltaic module, called target, potentially defective.
• the computer 5 comprises several functional software modules described below, which make it possible to carry out intermediate calculations necessary for estimating the electrical power of the photovoltaic module.
• the acquisition means can also be configured to acquire the electric current supplied by each photovoltaic module of the group i of photovoltaic modules at the maximum power point, referenced I mp pt(i>D (A), and the voltage at the terminals of each photovoltaic module of group i of photovoltaic modules at the maximum power point, referenced V mppt (i,D (V).
• the method of the invention firstly makes it possible to estimate the electrical power of a photovoltaic module present in a group i of photovoltaic modules.
• the process follows the steps described below.
• WindSpeed (m/s): Wind speed; Furthermore, as the inclination and orientation of the photovoltaic modules in each group i of photovoltaic modules are known, the computer 5 can determine the parameter:
• Step E1 Acquisition of temperature data at the level of each photovoltaic module and determination of the average temperature of each photovoltaic module
• the reference module Mref is a photovoltaic module analogous to the monitored and targeted photovoltaic module (that is to say with the same technical characteristics - with the same orientation and the same inclination) and not defective. It is part of the same group i of photovoltaic modules as the monitored photovoltaic module. It has a uniform temperature distribution over all of its zones. In other words, it does not include any hot thermal zone in the sense defined above during step E1.
• two modules M1, 1, M1, 2 of group 1 of photovoltaic modules have been shown. One of the two is defective and the other photovoltaic module is healthy and can thus be chosen as the reference photovoltaic module Mref.
• the computer 5 can estimate the theoretical electrical power that a healthy photovoltaic module, that is to say the reference module, would be able to supply.
• the calculator is based on the following formula (equation (2)):
• One of the principles of the invention consists in determining corrected environmental parameters taking into account constraints on the energy balance of the modules and on the electrical power P mppt (i) delivered at the maximum power point by the group i of photovoltaic modules , and a weighting function applied to the acquired environmental parameters.
• the calculator can also rely on the following expression f:
• CP mppt which corresponds to the tolerance allowed with respect to the power P mppt (i) acquired during step E2.
• the tolerance can be set at 3%;
• Tamb c (P) Tamb c (i,j)Vj
• step E2 in an improved version, it is possible to have measurements of the current l mppt (S) which crosses the entire chain of photovoltaic modules (i.e. the group i) and voltage V mppt (i) at the terminals of group i of photovoltaic modules.
• G(i) being the measured or estimated irradiance, respectively on a photovoltaic module of the group i of photovoltaic modules.
• the computer 5 will estimate the voltage at the terminals of each other photovoltaic module of the group i of photovoltaic modules. For each photovoltaic module of group i of photovoltaic modules, it must be taken into account that its voltage V mppt (i,j) can be reduced depending on the number of active bypass diodes. We can therefore add a variable which corresponds to the number of diodes activated for each photovoltaic module, referenced DiodeActive(i,_r) e ⁇ 0,1,2, .. , N diode ⁇ . N diode is the total number of diodes in the photovoltaic module. A continuous degradation factor is also added: Degrade (iJ) e [0.1], This factor makes it possible to take account of the level of aging of each module, which may vary from one module to another.
• the computer 5 is required to solve the optimization problem mentioned above (step 5.1 and step 5.2 if executed). This is a non-linear optimization problem that can be solved with "fmincon" type solvers.
• the computer 5 By determining this power loss for each photovoltaic module, the computer 5 is able to identify, within a group of several photovoltaic modules, the photovoltaic modules which are defective, for example by comparing the power loss calculated for the photovoltaic module with a stored threshold value. Each photovoltaic module declared as defective may be subject to specific diagnostic and/or maintenance actions.
• the step EO is implemented by the environmental data acquisition means of the system. This means, for example, measuring wind speed, ambient temperature and irradiance. This data can also be retrieved by the computer by connecting to a remote weather server.
• a remote weather server in a non-limiting manner, we have represented the various sensors 2, 3, 4 necessary for taking these measurements.
• Step E1 is implemented both by the temperature data acquisition device and by a processing module MT of the computer 5, responsible for processing the measurement data to assign an average temperature to each photovoltaic module.
• the data acquisition is carried out by the thermal camera 1 .
• Step E2 is implemented thanks to the inverter 6 responsible for transmitting the electrical data of the group i of photovoltaic modules and to a module for acquiring the electrical data relating to the group i of photovoltaic modules, this acquisition module being integrated into the calculator.
• the optional step E3 is implemented by a selection module MS of the computer 5, the latter being responsible for selecting at least one reference photovoltaic module Mref.
• the optional step E4 is implemented by a first calculation module MC1 of the computer 5, intended to calculate the theoretical electric power P eiec (i,_T) supplied to a healthy photovoltaic module.
• Step E5 is implemented by a second calculation module MC2 of the computer, intended to solve the optimization problem with a view to determining the three environmental parameters sought.
• the module MC2 can in particular use the measurements of current / mppt (0 (A) of the voltage V mppt (i) (V) at the level of group i of modules photovoltaic cells and estimate the corrected electrical power P eiec (i,j) in order to facilitate obtaining the desired environmental parameters.
• Step E6 is implemented by a third calculation module MC3 of the computer, intended to estimate the actual electrical power Pelec c (i,f) supplied by each photovoltaic module Mi,j and the power loss PowerLoss(i,f ) of each photovoltaic module.
• G arr(0 which is the solar irradiance received by the rear face of the photovoltaic module; It can come from a measurement or an estimate from a model;

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• Photovoltaic Devices (AREA)
• Supply And Distribution Of Alternating Current (AREA)

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• 2020
  • 2020-12-17 FR FR2013440A patent/FR3118363B1/fr active Active
• 2021
  • 2021-12-13 WO PCT/EP2021/085524 patent/WO2022128933A1/fr unknown
  • 2021-12-13 EP EP21854869.1A patent/EP4264824A1/de active Pending

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