US-12620933-B2 - Method for forecasting electrical power in real time of a photovoltaic plant

US12620933B2US 12620933 B2US12620933 B2US 12620933B2US-12620933-B2

Abstract

A is a method for forecasting electrical power in real time of a photovoltaic plant includes recording a set of operating data; entering for each set of operating data a respective electrical power value recorded in a cell for insertion of a power matrix and dividing the recorded electrical power value to obtain an efficiency value. The efficiency value in a cell of an efficiency matrix is entered and a power value contained in a cell of the power matrix and an efficiency value contained in a cell of the efficiency matrix identified. The power value and the efficiency value are multiplied to derive an expected electrical power value and the expected electrical power value is compared with the corresponding electrical power value acquired in real time identifying an operating condition of the photovoltaic plant as a function of the comparison.

Inventors

Alessandro BUSCEMI

Assignees

AVATR S.R.L. STARTUP COSTITUITA AI SENSI DELL'ART. 4 COMMA 10 BIS D.L. 3/2015 CONV. CON LEGGE 33/2015
Alessandro BUSCEMI

Dates

Publication Date: 20260505
Application Date: 20220117
Priority Date: 20210125

Claims (9)

1 . A method for providing electrical power in real time of a photovoltaic plant comprising the steps of: providing that said photovoltaic plant comprises a plurality of photovoltaic modules interconnected with each other, a plurality of sensors each operatively connected with at least one of said plurality of photovoltaic modules, a plurality of inverters each operatively connected with a respective group of said plurality of photovoltaic modules and a processing and control unit configured to perform said steps below; i. recording, in each predetermined time interval of a recording period, a set of operating data of the photovoltaic plant, said set of operating data comprising at least: an average overall solar radiation received from the photovoltaic plant; an average temperature of modules of the photovoltaic plant; a solar height with respect to the photovoltaic plant; a solar azimuth with respect to the photovoltaic plant; an electrical power output from the photovoltaic plant; said step of recording the set of operating data of the photovoltaic plant being performed by acquiring at least some data of the set of operating data at least by said plurality of sensors; at the end of the recording period the method comprising the steps of: ii. initializing a power matrix and an efficiency matrix, said power matrix having a plurality of columns each representing a range of global solar radiation values and a respective plurality of rows each representing a range of average temperature values, said efficiency matrix having a plurality of columns each representing a range of solar height values and a respective plurality of rows each representing a range of solar azimuth values; iii. entering for each set of operating data a respective electrical power value recorded in a cell for inserting in said power matrix having coordinates corresponding, respectively, to the value of the average overall solar radiation and the average temperature recorded for the same set of operating data; iv. if in said insertion cell there is a previous value relative to an average power, updating the value of the average power using the electrical power value recorded and recording the updated average power value in said insertion cell; v. dividing said recorded electrical power value by said updated average power to obtain an efficiency value; vi. inserting said efficiency value in a cell of said efficiency matrix having coordinates corresponding, respectively, to the value of the solar height and of the solar azimuth recorded for the same set of operating data; vii. if in said insertion cell there is a previous value relative to an average efficiency, updating the value of the average efficiency with said efficiency value and recording, in said insertion cell, the updated value of the average efficiency; viii. repeating the steps from iii to vii until an interruption criterion is verified; the method then comprises the following steps: ix. acquiring, in real time, the set of operating data of the photovoltaic plant; x. identifying a power value contained in a cell of said power matrix identified by intervals of overall solar radiation values and average temperature values which contain the values corresponding to said average overall solar radiation and to said average temperature acquired in real time; xi. identifying a further efficiency value contained in a cell of said efficiency matrix identified by intervals of solar height values and solar azimuth values which contain the values corresponding to said solar height and to said solar azimuth acquired in real time; xii. multiplying said power value and said further efficiency value to derive an expected electrical power value; xiii. comparing said expected electrical power value with the corresponding electrical power value acquired in real time; xiv. identifying an operating condition of the photovoltaic plant as a function of said comparison; xv. sending an alarm signal if an operating condition is identified representing a malfunction of said photovoltaic plant.
2 . The method according to claim 1 , wherein said recording step comprises the sub-steps of storing each set of operating data in a respective row of a storage matrix.
3 . The method according to claim 2 , wherein, after said recording step, the method further comprises the steps of: defining a plurality of conditions of acceptance of the values contained in each set of operating data recorded; applying said plurality of conditions of acceptance to each row of said storage matrix to cause an acceptance or a rejection of said set; creating a training matrix containing, in each row, a set of operating data of said storage matrix respecting the acceptable conditions.
4 . The method according to claim 1 and further comprising the steps of: initializing a first counter matrix and a second counter matrix, said first counter matrix having a plurality of columns and a plurality of rows representing the same intervals as said plurality of columns and rows of the power matrix, said second counter matrix having a plurality of columns and a plurality of rows representing the same intervals as said plurality of columns and rows of the efficiency matrix; and for each set of operating data: increasing by a unit the value contained in a cell having coordinates defined by the value of the average overall solar radiation and the average temperature recorded for said set of operating data; increasing by a unit the value contained in a cell having coordinates defined by the value of solar height and the solar azimuth recorded for said set of operating data.
5 . The method according to claim 4 , wherein said updating steps comprise the following sub-steps: multiplying the value present in the insertion cell with the value contained in the corresponding cell of the first or second counter matrix; adding the value obtained from the multiplying step with the value inserted in said power matrix or in said efficiency matrix in the insertion step; dividing the value obtained by said adding step by the value in said cell of the first or second counter matrix increased by a unit.
6 . The method according to claim 1 , wherein during said step of repeating the steps from iii to vii, the method also comprises for each set of operating data the steps of: identifying a power value contained in a cell of said power matrix identified by intervals of overall solar radiation values and average temperature values which contain the values corresponding to said average overall solar radiation and to said average temperature of the same set of operating data; identifying said further efficiency value contained in a cell of said efficiency matrix identified by intervals of solar height values and solar azimuth values which contain the values corresponding to said solar height and to said solar azimuth of the same set of operating data; multiplying said power value and said further efficiency value identified to derive an expected electrical power value; calculating a relative error between said expected electrical power and the electrical power of said set of operating data; determining the interruption criterion as a function of said relative error.
7 . The method according to claim 1 , wherein the step of identifying a power value comprises a sub-step of interpolating said power value with power values of said power matrix adjacent to the cell containing said power value and wherein said step of identifying said further efficiency value comprises a sub-step of interpolating said further efficiency value with efficiency values of said efficiency matrix adjacent to the cell containing said further efficiency value, the interpolations being bi-linear.
8 . A photovoltaic plant for producing electrical power comprising: a plurality of photovoltaic modules interconnected with each other; a plurality of sensors each operatively connectedassociated with at least one of said plurality of photovoltaic modules; a plurality of inverters each operatively connected with a respective group of said plurality of photovoltaic modules; a processing and control unit configured to perform a method for providing electrical power in real time of the photovoltaic plant comprising the steps of: i. recording, in each predetermined time interval of a recording period, a set of operating data of the photovoltaic plant, said set of operating data comprising at least: an average overall solar radiation received from the photovoltaic plant; an average temperature of modules of the photovoltaic plant: a solar height with respect to the photovoltaic plant: a solar azimuth with respect to the photovoltaic plant; an electrical power output from the photovoltaic plant; said step of recording the set of operating data of the photovoltaic plant being performed by acquiring at least some data of the set of operating data at least by said plurality of sensors; at the end of the recording period the method comprising the steps of: ii. initializing a power matrix and an efficiency matrix, said power matrix having a plurality of columns each representing a range of global solar radiation values and a respective plurality of rows each representing a range of average temperature values, said efficiency matrix having a plurality of columns each representing a range of solar height values and a respective plurality of rows each representing a range of solar azimuth values; iii. entering for each set of operating data a respective electrical power value recorded in a cell for inserting in said power matrix having coordinates corresponding, respectively, to the value of the average overall solar radiation and the average temperature recorded for the same set of operating data; iv. if in said insertion cell there is a previous value relative to an average power, updating the value of the average power using the electrical power value recorded and recording the updated average power value in said insertion cell; v. dividing said recorded electrical power value by said updated average power to obtain an efficiency value; vi. inserting said efficiency value in a cell of said efficiency matrix having coordinates corresponding, respectively, to the value of the solar height and of the solar azimuth recorded for the same set of operating data; vii. if in said insertion cell there is a previous value relative to an average efficiency, updating the value of the average efficiency with said efficiency value and recording, in said insertion cell, the updated value of the average efficiency; viii. repeating the steps from iii to vii until an interruption criterion is verified; the method then comprises the following steps: ix. acquiring, in real time, the set of operating data of the photovoltaic plant; x. identifying a power value contained in a cell of said power matrix identified by intervals of overall solar radiation values and average temperature values which contain the values corresponding to said average overall solar radiation and to said average temperature acquired in real time; xi. identifying a further efficiency value contained in a cell of said efficiency matrix identified by intervals of solar height values and solar azimuth values which contain the values corresponding to said solar height and to said solar azimuth acquired in real time; xii. multiplying said power value and said further efficiency value to derive an expected electrical power value; xiii. comparing said expected electrical power value with the corresponding electrical power value acquired in real time; xiv. identifying an operating condition of the photovoltaic plant as a function of said comparison; xv. sending an alarm signal if an operating condition is identified representing a malfunction of said photovoltaic plant.
9 . The photovoltaic plant according to claim 8 , wherein said processing and control unit is configured to perform said method for each group of modules connected to an inverter of the plurality of inverters of said photovoltaic plant.

Description

This application is the National Phase of International Application PCT/IB2022/050343 filed Jan. 17, 2022 which designated the U.S. This application claims priority to Italian Patent Application No. 102021000001346 filed Jan. 25, 2021, which applications are incorporated by reference herein. This invention relates to a method for analysing and forecasting in real time the electrical power of a photovoltaic plant which is widely used in the field of renewable energy, in particular in the field of solar energy. A photovoltaic plant is an electricity plant equipped with a solar energy collection system which uses photovoltaic modules and produces electricity. It is known that photovoltaic modules are subject to temporary or permanent drops in efficiency in the production of electrical power due to different factors such as, for example, temperature variations, amounts of dirt of the surface areas, total or partial breakages of the modules, total and partial shading, spontaneous deterioration of the modules, environmental conditions and the like. Currently, the need is particularly felt for monitoring the production of electrical power of the photovoltaic plants in such a way as to monitor their production of energy in order to better manage the request and the demand for the energy market and in such a way as to better manage the economic aspects of the plants. For this purpose, there are prior art systems and methods which are able to collect data which can be detected by the photovoltaic plant for providing a function of simple display or statistical processing of the data. Disadvantageously, many of the monitoring systems currently used are able to identify faults and malfunctions of the various components of the plant (modules and inverters) but are not able to measure efficiency drops linked to the variations of the ambient conditions of the plant such as, for example, the effect of the presence of shading on the modules. Disadvantageously, the prior art systems are not able to automatically perform the calibration and the checking of accuracy of the models for forecasting the electrical power at the output from the plant without the aid of operators who can carry out technical and statistical analyses of the data collected by the plant. Disadvantageously, the prior art methods are not able to automatically detect the effect of shading by buildings or vegetation on the efficiency of the plant as a function of the position of the sun or are not able to determine the lack of electrical production due to the presence of snow covering on the modules. The technical purpose of the invention is therefore to provide a method for forecasting in real time the electrical power of a photovoltaic plant which is able to overcome some of the drawbacks of the prior art including the possibility of taking into account the effect of shading on the efficiency of the photovoltaic plant. The aim of the invention is therefore to provide a method for forecasting in real time the electrical power of a photovoltaic plant which is automated and fast. A further aim of the invention is to provide a method for forecasting in real time the electrical power of a photovoltaic plant which can be easily implemented. A further aim of the invention is to provide a method for forecasting in real time the electrical power of a photovoltaic plant which is able to forecast the electrical power of the photovoltaic plant in an efficient and reliable manner. A further aim of the invention is to provide a method for forecasting in real time the electrical power of a photovoltaic plant which is able to derive information regarding the presence and the energy impact of any malfunction or decrease of performance not highlighted by faults detected by the traditional systems for monitoring the plants. The technical purpose indicated and the aims specified are substantially achieved by a method for forecasting in real time the electrical power of a photovoltaic plant comprising the technical features described in one or more of the appended claims. The dependent claims correspond to possible embodiments of the invention. Further features and advantages of the invention are more apparent in the non-limiting description which follows of a non-exclusive embodiment of a method for forecasting in real time the electrical power of a photovoltaic plant. The description is set out below with reference to the accompanying drawings which are provided solely for purposes of illustration without restricting the scope of the invention and in which: FIG. 1 is a plan diagram of a photovoltaic plant; FIGS. 2A and 2B show respective approximate reconstructions of power and efficiency functions. With reference to the accompanying drawings, the numeral 100 denotes a photovoltaic plant comprising a plurality of modules 10 interconnected with each other. The modules 10 may be connected to each other according to connections in series or in parallel. In particular, the module