Method and device for mapping operating conditions of mini wind turbines

Abstract

The invention describes a device (2) and a computer-implemented method for mapping operating conditions of mini wind turbines, comprising the following steps: - receiving records of the operation of a mini wind turbine (1); - forming a map of operating conditions of the mini wind turbine (1) using the received records, the records being included in the map as recorded points, according to the following particularities: any record inconsistent with a reference state of the mini wind turbine (1), corresponding to the moment at which the method is initiated, is discarded and, consequently, not included in the map; and when a record is received that is consistent with the reference state but inconsistent with the map formed up to that point, new records stop being included in the map and mapping finishes.

Description

[0001]DESCRIPTION Method and equipment for mapping the operating conditions of mini-wind turbines. TECHNICAL SECTOR The present invention relates generally to the field of wind turbines, and more specifically to the field of characterizing the operation of mini-wind turbines. BACKGROUND OF THE INVENTION The generation of energy by means of mini-wind turbines has differential characteristics with respect to wind power due to the fact that the cost per kW of the equipment and installations is much higher than that of the latter, which determines the inclusion of complex monitoring systems to achieve generation costs competitive with other technologies.Properly constructing a mini-wind turbine's operating conditions map is important for understanding its performance and providing a comparison base that is as accurate as possible to reality. This allows for later evaluation of the mini-wind turbine's performance; for example, to detect potential malfunctions, anticipate breakdowns, obtain energy production estimates, improve operating efficiency, etc.Traditionally, mini-wind turbine operating data recording is carried out, in any case, through two distinct alternatives: a) collecting data on very basic operating aspects (such as, for example, temporary records of generated power) within the grid-connected converter itself; or b) collecting data on more complete and detailed operating aspects (usually because this is deemed appropriate after detecting a substantial and sustained loss of generating capacity over time), using measuring and recording equipment that is not part of the standard installation. Option a) collects very basic operating data that does not allow for the establishment of correlations that could be considered a map of the mini-wind turbine's operating conditions.According to option b), expensive measurement and data acquisition equipment is required, as well as the time of qualified technical personnel to install the equipment, operate it, collect the data, process it, analyze it and draw conclusions. In short, neither option is suitable for generating an operating condition map, either because they are not effective or because they are not economically efficient. SUMMARY OF THE INVENTION The present invention overcomes the drawbacks of the prior art by providing a method and equipment for mapping the operating conditions of mini-wind turbines. More specifically, according to a first aspect of the invention, a computer-implemented method for mapping the operating conditions of mini-wind turbines is provided, comprising the following actions: - Records of the operation of a mini-wind turbine are received.Each record consists of voltage and current values ​​from a series of samples of an electrical signal from the mini-wind turbine at a respective operating moment. - A map of the operating conditions of the mini-wind turbine is created with the received records, and these records are integrated into the map in the form of recorded points, also referred to as "points" for short. The map is created according to the following specific features: ^ Any record that is inconsistent with a reference state of the mini-wind turbine, which is the state of the mini-wind turbine at the start of the method, is discarded and, consequently, not integrated into the map. ^ When a record is received that is consistent with the reference state but is not consistent with the map created up to that point, the incorporation of new records into the map is stopped, and the mapping is considered complete.As used herein, the term "computer" is to be understood in a broad and non-limiting sense, encompassing both a computer and any other programmable medium, for example, a microcontroller, a console, an electronic tablet, a PDA, a mobile phone, a computer network, etc. In this document, mapping the operating conditions of a mini-wind turbine is to be understood as the generation of correlations between different operating magnitudes of the mini-wind turbine that characterize its operating state over an operating range similar to that expected at its installation site. In the present invention, said correlations are represented in the form of points that, together, make up a map of operating conditions. The magnitude values ​​corresponding to these points are called "mapping values."A point can be integrated into the operating conditions map in various ways, consistent with the typology of the operating conditions map. For example, it can be graphically integrated into one or more coordinate graphs, it can be integrated into one or more tables of values, etc. In this document, the terms "operating map" or simply "map" are also used to refer in a simplified manner to the "operating conditions map." Regarding the action corresponding to receiving records of the operation of a mini-wind turbine: The method of the present invention can develop the mapping from received record data, without having to deal with the actual acquisition of said records.However, according to a particular embodiment, the method can also handle the actual acquisition of the records by means of a sensor means (preferably consisting of a voltage sensor and a current sensor) that captures voltage and current values. Preferably, each record includes 36 samples per period at a constant time step, up to 10 periods. According to a particular embodiment, the received records are subjected to digital filtering at a cutoff frequency equal to twice the fundamental frequency. Regarding the action corresponding to forming a map of the operating conditions of the mini-wind turbine with received records: According to a particular embodiment, the operating conditions map is made up of values ​​corresponding to two or more of the following electrical quantities: frequency, voltage, current, power.According to a more particular embodiment, frequency is one of the electrical quantities whose values ​​make up the operating conditions map. Thus, according to this more particular embodiment, the operating conditions map is made up of values ​​corresponding to two or more electrical quantities, one of which is frequency and the rest are one or more of the following: voltage, current, power. Preferably, the following particularities are taken into account: - the voltage value of a record integrated into the map corresponds to the average of the voltage spatial phasor module (^). ^^^ ) for the samples that make up the record, obtaining ^ ^^^ , for example, by the following equation: in which: ^ ^^ , ^ ^^ line voltages; - the current value of a record that is integrated into the map corresponds to the average of the current spatial phasor module (^ ^^^) for the samples that make up the record, obtaining ^ ^^^ , for example, by the following equation: in which: ^ ^ , ^ ^ , ^ ^ the instantaneous line currents; - the power value of a record integrated into the map corresponds to the average of the instantaneous powers in a sample ^ (^(^)) for the samples that make up the record, obtaining ^(^), for example, by the following equation (VI): where: ^ the function ^^ returns the real part of the complex to which it is applied; ^ ^ ^^^ ( ^ ) : is the spatial phasor of stress in the sample ^; ^ ^ ∗ ^̅^^(^): is the complex conjugate of the current spatial phasor in the sample ^. According to a particular embodiment, the operating conditions map is made up of several two-dimensional graphs in which the values ​​of the following pairs of magnitudes are represented, in a related manner: - a two-dimensional graph with frequency values ​​and current spatial phasor modulus values; - a two-dimensional graph with frequency values ​​and voltage spatial phasor modulus values; - a two-dimensional graph with frequency values ​​and power values. According to a particular embodiment, the operating conditions map is formed between a minimum frequency and a maximum operating frequency, according to the following particularities: - The map is divided into nf frequency intervals, which, preferably, have the same amplitude in frequency.More preferably, the value of nf is the smallest positive integer that causes the width of the frequency intervals in percent of the minimum operating frequency to be less than the smaller of a set of transient discrimination thresholds (ℎ. ^^ , ℎ ^^ ), which are defined below. - The record or records belonging to the same frequency interval are integrated into the map as a recorded point, whose mapping values ​​are average values ​​of the record or records of said interval. For clarification, a record belongs to a frequency interval if the frequency value of the record is within the frequency interval. According to a particular embodiment, the integration of a new record into the operating conditions map entails updating each of the mapping values ​​corresponding to the frequency interval to which the new record belongs, according to the following equation: (VII) in which: - ^ ^^,^^^ : is the updated mapping value corresponding to a magnitude ^, taking into account the new record; - ^: is the number of records that have contributed to the formation of the recorded point before the new record; - is the mapping value corresponding to the magnitude ^ before the new record; - ^ ^ : is the received value corresponding to the magnitude ^ of the new record. For clarification, in view of equation VII, if the new record is the first record of a frequency interval, the updated mapping value corresponding to a magnitude ^ is the received value itself corresponding to the magnitude ^ of the record (X ^^,^^^ = ^ ^), since, in this case, ^ = 0. According to a particular embodiment, the mapping method comprises the following actions: - Once mapping starts, the first stationary record is always mapped. - Starting from that first stationary record, each additional stationary record is integrated or not into the map depending on the following options: a. If the additional stationary record corresponds to a frequency interval that has not yet received any mapped points: the point corresponding to the additional stationary record is stored waiting to be validated. b. if the additional stationary record corresponds to a frequency interval that has previously received some mapped points, one of the following actions is performed, depending on the consistency of the record with the existing map: b.i) If the point corresponding to the additional stationary record does not deviate from the existing map, that point and all previously stored points are mapped, each in its corresponding frequency interval. Once mapped: If the minimum number of records that have contributed to obtaining the mapping values ​​in each of all the frequency intervals is greater than or equal to a minimum number (nmin) established, preferably with a value set to 3, the mapping is finished. Otherwise, the mapping continues. b.ii) If the point corresponding to the additional stationary record deviates from the existing map, the mapping is finished.Regarding the specific feature of map formation related to record discarding: In this document, a record is understood to be inconsistent with the reference state when the record corresponds to a non-stationary state; that is, when the series of samples comprising the record is not stationary. In contrast, a record is understood to be consistent with the reference state when the record corresponds to a stationary state; that is, when the series of samples comprising the record is stationary. As is well known, the stationarity of a time series of data is a property that gives an idea of ​​how permanent the statistical properties of the series (e.g., the mean, variance, covariance) are over time; and the transience of a time series of data is defined in the opposite sense to stationarity.Thus, a time series of data is considered stationary if its statistical properties remain constant over the time in which the series is observed. Conversely, a time series of data is considered transient if its statistical properties do not remain constant over the time in which the series is observed. During the operation of a mini-wind turbine, small alterations that affect the operating state are very likely to occur, so it is very easy for a state to become non-stationary in the strict sense. Strict consideration of stationarity in the application of this method would lead to results that are overly restrictive and of little use in most cases, and could even arise situations in which it would not be possible to create a map of operating conditions.Therefore, the present invention uses the concept of stationarity in a broader sense, accepting a tolerance in its analysis. Consequently, in this document, when the term "stationary" or derivatives is used in reference to a series of samples, a record, or an operating state, it refers to a series of samples, a record, or an operating state with low transience; this is understood as a transience whose value is below an established stationarity limit condition. The stationarity limit condition is established based on the precision required for the operating map, as well as the amount of resources and time worth investing in the mapping. The more restrictive the stationarity limit condition, the more precise a map can be achieved, but this requires more time and resources (e.g., more processing capacity, greater energy expenditure, etc.).); since it is more difficult to find valid points to be integrated into the map, and, consequently, a greater number of records must be captured to be able to integrate enough points into the map. Preferably, the stationarity boundary condition consists of two transient discrimination thresholds: a voltage transient discrimination threshold (ℎ. ^^ ), and a current transient discrimination threshold (ℎ ^^ ). More preferably, both the voltage transient discrimination threshold (ℎ ^^ ) as the current transient discrimination threshold (ℎ ^^) are set to 0.05. Various methods are known in the art for determining the stationarity of a time series of data, such as, for example, visual methods in which the data series represented in the form of a graph is visually analyzed; Dickey-Fuller method, etc. In the present invention, the stationarity of each record is preferably determined by analyzing the series of samples that make up the record, comprising the following actions: - the spatial voltage phasor (^) is calculated ^^^ ) using the following equation: 1 1 ^ ^^^ = 3 ( 2^ ^^ + ^ ^^ ) + ^ ^ (I) √ 3 ^^ in which ^ ^^ , ^ ^^ are the line voltages; - the spatial current phasor (^) is calculated ^^^ ) using the following equation: in which ^ ^ , ^ ^ , ^ ^are the instantaneous line currents; - the instantaneous speed of the voltage space phasor is calculated and the instantaneous velocity of the current space phasor each sample of the record, using the following equation: ∗ ^ ( k ) · ^ ( k − 1 ^^^ ^ ^^^ ^^^ ) ∗ ^ ^^ ^^^ ( k ) ^ · ^^ ^^^ ( k − 1 ) ^ ω ^^^^ ( ^ ) = Δ^ ( III ) where: ^ k refers to a k-th sample from the series of samples obtained corresponding to the record, ^ ω ^^^^ (^) is the instantaneous velocity of the spatial phasor of magnitude x in sample k, the magnitude x being able to refer to voltage or current, depending on whether , respectively, ^ ^^^ refers to the mathematical function “argument”, It is the spatial phasor of the magnitude X in a sample k, the magnitude X being able to refer to voltage or current, in coherence with the magnitude x referred to in ∗ ^ ^ ^^^ ( k − 1 ) is the complex conjugate of the spatial phasor of the magnitude X in the sample k-1, the magnitude X being able to refer to voltage or current, in coherence with the magnitude x referred to in ω ^^^^ ( ^ ) , ^ Δ^ refers to the sampling time step between sample k and the previous sample k-1; - the moving average of the instantaneous velocity of the spatial voltage phasor (^) is calculated ) ), and the moving average of the instantaneous velocity of the spatial current phasor (^ ) ) using equation IV, preferably for half the period of the electrical signal: in which: ^ ω^ ^^^^ ( ^ )is the moving average of the instantaneous velocity of the spatial phasor of magnitude x for mm samples; the magnitude x may refer to voltage or current, depending on whether ω^ ^^^^ (^) refers to ω^ ^^^^ (^) or ω ^^^^ (^), respectively, ^ ^ refers to the summation index, ^ ω ^^^^ ( ^ + 1 − ^ ) is the instantaneous velocity of the spatial phasor of the corresponding magnitude x in the sample ^ + 1 − ^; the magnitude x can be referred to voltage or current in coherence with the magnitude x referred to in ω^ ^^^^ (^); - the transient voltage discrimination coefficient (^) is calculated ^^ ) and the transient current discrimination coefficient (^ ^^ ) using the following equation: in which: ^ ^ ^^is the transient discrimination coefficient of a magnitude x for a period with m samples in which m‐mm moving averages are calculated; the magnitude x may refer to voltage or current, depending on whether ^ ^^ refers to ^ ^^ oa ^ ^^ , respectively, ^ the max functions They return the maximum, minimum and average values, respectively, corresponding to the set of moving averages that are defined for the instantaneous velocity of the spatial phasor of the corresponding magnitude x over a complete sample record; the magnitude x can be referred to voltage or current, in coherence with the magnitude x referred to in ^ ^^ ; - the stationarity of the record is determined by comparing the calculated value of the voltage transient discrimination coefficient ( ^ ^^ ) with a voltage transient discrimination threshold established, and the calculated value of the transient current discrimination coefficient ( ^ ^^ ) with a current transient discrimination threshold (ℎ ^^ ) established. Preferably, a record is considered to be stationary only if the voltage transient discrimination coefficient (^ ^^ ) is lower than the voltage transient discrimination threshold (ℎ ^^ ) and, in addition, the transient current discrimination coefficient is lower than the current transient discrimination threshold (ℎ ^^); otherwise, the record is considered to be non-stationary. Regarding the particularity of map formation regarding stopping the incorporation of new records into the map and completing the mapping: In this document, a record is to be understood as not being consistent with the map formed up to the time at which the record was obtained, when it deviates from said map by an amount equal to or greater than an established deviation threshold. Preferably, the condition for considering that a record deviates from the operating conditions map formed up to the time at which the record was obtained is that the absolute value of the deviation of the corresponding recorded point is not less than the established deviation threshold for one of the magnitudes under study.Preferably, the deviation of the recorded point, for one of the quantities under study, is defined as the difference between the following two values: - the absolute percentage difference between the value of the magnitude of the point to be mapped and the previous mapped value of that magnitude in the corresponding frequency interval; and - the percentage frequency difference between the point to be mapped and the previous mapped frequency in the corresponding frequency interval. The value of the "deviation threshold" parameter is set according to the accuracy required for the operating conditions map. The lower the deviation threshold value, the more accurate the values ​​integrated into the map, but the more likely it is that a deviated recorded point will appear, and the mapping will be terminated before it can be completed (and, consequently, the map will not have the desired level of detail).Preferably, the deviation threshold is set as twice the largest of the established transient discrimination thresholds (ℎ. ^^ , ℎ ^^), multiplied by 100. According to a second aspect, the present invention also provides equipment for mapping the operating conditions of mini-wind turbines, comprising programmable processing means adapted to carry out the method according to the first aspect of the present invention. According to a particular embodiment, the equipment also comprises sensor means, preferably consisting of a voltage sensor and a current sensor, intended for the following functions: - capturing voltage values ​​and current values ​​of electrical signals from a mini-wind turbine under study, preferably in a link line between the mini-wind turbine and a grid converter; - transmitting the captured values ​​to the programmable processing means. The equipment may also comprise an AC-DC converter between the mini-wind turbine and the programmable processing means. According to a particular embodiment,The equipment comprises a communication means by which data can be received and / or transmitted (for example, to provide access to mapping results). The communication means can be made up of a transmitting means and a receiving means, either of which can be, for example, wireless. The present invention also relates to a computer program with instructions which, when the program is executed on a computer, cause the computer to carry out the method according to the first aspect of the invention. The present invention also relates to a computer-readable data storage medium, comprising the computer program. Advantages of the present invention with respect to the prior art: - The implemented methodology makes it possible to discriminate records corresponding to transient operating states or those with a high degree of transience,This reduces the dispersion of the points defining the mini-wind turbine's operating map, allowing lower deviation thresholds relative to the map to be set, thus achieving a more precise operating map and a better-defined discrimination of the current state with respect to the reference state. - The operating map produced is self-validated, since a record outside the previous map only contributes to the map if the consistency of a subsequently acquired record is checked with a record for which consistency with the reference state has previously been recorded (and which therefore forms part of the partial map). - As a consequence of self-validation, the map may or may not contain complete information on the operating range assigned to the mini-wind turbine.but the information it contains represents the reference state of the mini-wind turbine for a period of time in which the map is consistent with the actual operation of the mini-wind turbine and which starts at the time the mapping starts. - According to a preferred embodiment, the transience discrimination procedure is based on the variability of the instantaneous velocity of the voltage and current spatial vectors, proportional to their instantaneous frequency. This avoids the use of the concept of frequency associated with a period and the associated search for specific patterns in consecutive periods to define its duration (zero crossings, peaks, etc.), significantly improving the precision of the parameter thus defined. - According to a preferred embodiment, the discrimination process uses moving averages to reduce the irrelevant variability of the instantaneous velocity of the voltage and current spatial vectors produced, for example,due to noise in the measurement or due to the effect on the measurement of the filtering stage before and after digitization. This avoids the dispersion in the frequency estimation that gives rise to less precise recordings. Throughout the description and claims, the word "comprises" and its variants are not intended to exclude other technical features, additives, components or steps. Furthermore, the word "comprises" includes the case "consists of". For those skilled in the art, other objects, advantages and characteristics of the invention will be derived partly from the description and partly from the practice of the invention. The following examples are provided by way of illustration, and are not intended to be limiting of the present invention. Furthermore, the present invention covers all possible combinations of embodiments indicated herein. BRIEF DESCRIPTION OF THE DRAWINGS The present invention will be better understood with reference to the following figures,wherein, for illustrative and non-limiting purposes, the following is represented: Figure 1 is a diagram showing the operational sequence of a method for mapping the operating conditions of mini-wind turbines, according to a preferred embodiment of the present invention. Figures 2 to 14 show an example 1 of mapping the operation of a mini-wind turbine, in which the state of the mini-wind turbine does not change throughout the mapping process. Figure 15 shows an example 2 of mapping the operation of a mini-wind turbine, in which the state of the mini-wind turbine changes throughout the mapping. Figure 16 shows equipment for mapping the operation of a mini-wind turbine, according to a preferred embodiment of the invention. MODES OF EMBODIMENT OF THE INVENTION According to a first aspect of the invention, a method for mapping the operating conditions of mini-wind turbines, implemented by computer, is disclosed. In general,The mapping method according to the present invention comprises the following actions: - records of the operation of a mini-wind turbine (1) are received, each record being made up of voltage and current values ​​of a series of samples of an electrical signal from the mini-wind turbine (1) at a respective moment of operation; - a map of the operating conditions of the mini-wind turbine (1) is formed with the received records, the records being integrated into the map in the form of recorded points, according to the following particularities: ^ any record that is not consistent with a reference state is discarded and, consequently, is not integrated into the map, since it corresponds to a non-stationary operating state; the reference state being understood as the state of the mini-wind turbine (1) at the time of the start of the method; ^ when a record is received that is consistent with the reference state,but is not consistent with the map formed up to that moment, the incorporation of new records to the map is stopped, and the mapping is considered finished; understanding that a record is not consistent with the map formed up to that moment when it deviates from said map by an amount equal to or greater than an established deviation threshold. Preferably, the mapping of a mini-wind turbine (1) according to the method of the present invention is carried out at the place where the mini-wind turbine (1) is put into service. However, the method of the present invention can be carried out in other environments such as, for example, in a test bench (for example,forming part of a product development and / or improvement phase). The mapping method according to the present invention is self-validating based on the following aspect: Records whose coherence with the reference state cannot be guaranteed because they correspond to operating states with a high degree of transience are discarded. Specifically, the method uses an algorithm that prevents records that are inconsistent with the reference state from being incorporated into the operating map, thereby obtaining an operating map that is consistent with the operation of the mini-wind turbine (1) in the reference state. More specifically, according to a preferred embodiment, a preliminary operating data selection process is carried out taking into account the variability of the instantaneous frequency, such that data corresponding to operating situations with a high degree of transience can be discarded. In this document,The reference state is defined as the state of the mini-wind turbine (1) at the time the mapping starts. According to a preferred embodiment, the mapping method is also based on the following aspect: When a record is received with a low degree of transience but is not consistent with the map generated up to that point, the incorporation of new information into the map is stopped and the mapping is considered complete, even if the generated map does not have the detail established as the objective (in this way, the validity of the map to reflect the reference state is prioritized over its state of completion). According to a preferred embodiment, the operating map is made up of values ​​of the following electrical characteristics: frequency; complex space vector module of voltage, complex space vector module of current; and power. In this document,The terms "space voltage vector" or "voltage vector" are also used to refer in a simplified manner to the "complex space voltage vector". Likewise, the terms "space current vector" or "current vector" are also used to refer in a simplified manner to the "complex space current vector". According to a preferred embodiment, the invention features improvements to the transience discrimination methodology based on processing the instantaneous velocity of the wind turbine's voltage and current space vectors using moving averages, which reduces the dispersion of results and allows for lower deviation margins to be established. According to a preferred embodiment, the mapping method generally comprises: - Receiving data from operating logs of a mini-wind turbine,the data corresponding to values ​​of basic electrical magnitudes of the mini-wind turbine (1) at a respective moment of its operation; - processing said recording data to obtain significant operating parameters; - analyzing said parameters of each of the records to discriminate their degree of transience; and associated with this, analyzing the convenience of integrating each of the records into the operation map; and - generating the operation map. According to a more preferred embodiment, the method comprises the following steps: 1. Receiving operating data from the mini-wind turbine (1). Preferably, a record is acquired by capturing samples of voltage and current values ​​of an electrical signal from the mini-wind turbine (1) at a moment of its operation. The capture of the samples is carried out by means of a sensor means (4),which preferably comprises a voltage sensor and a current sensor. Preferably, data capture is performed at a constant time step of 36 samples per period, preferably, up to a total of 10 periods. 2. Data filtering. In order to reduce the impact of disturbances on the signal (e.g., noise, distortion, interference, etc.), according to a preferred embodiment, data filtering is preferably performed with a cut-off frequency twice the fundamental frequency. 3. Determining the stationarity of the record. Preferably, the stationarity of a record is assessed by means of a voltage transient discrimination coefficient (^, ^^ ) and a transient current discrimination coefficient (^ ^^). Preferably, the stationarity of the record is binary, so that it can take the values ​​true or false. These two values ​​can also be denoted in other ways, such as 1 or 0, respectively. According to a preferred embodiment, the stationarity of the record is considered to be true only if the voltage transient discrimination coefficient (^ ^^ ) is lower than a voltage transient discrimination threshold (ℎ ^^ ) and, in addition, the transient current discrimination coefficient (^ ^^ ) is less than a current transient discrimination threshold That is, both voltage and current transient discrimination coefficients must be lower than their respective transient discrimination threshold (ℎ ^^). In this document, a record with true stationarity is referred to as a “stationary record”; and a record with false stationarity is referred to as a “transient record”. The respective values ​​of the voltage transient discrimination thresholds (ℎ ^^ ) and current (ℎ ^^) can be adjusted to suit a specific installation, taking into account the following circumstance: if the number of records with low transience per unit of time is low (in the case where the stationarity of the record is binary, this condition means: if the number of stationary records is low), it is advisable to increase the transient discrimination thresholds; if the number of records with low transience is high (in the case where the stationarity of the record is binary, this condition means: if the number of stationary records is high), it is advisable to decrease the transient discrimination thresholds. Preferably, both the voltage transient discrimination threshold (ℎ ^^ ) as the current transient discrimination threshold (ℎ ^^) are set to the respective minimum possible value compatible with the natural dispersion of the records associated with the operation of the system and the measurement and recording process. According to a particular embodiment, both the voltage transient discrimination threshold (ℎ ^^ ) as the current transient discrimination threshold (ℎ ^^ ) are set to 0.05. Preferably, the value of the transient discrimination coefficient of a magnitude “x” is obtained according to the following sub-stages: calculation of spatial phasor (^̅ ^^^ ), calculation of instantaneous velocity from the spatial phasor calculation of the moving average of the instantaneous velocity of the spatial phasor Calculation of the transient discrimination coefficient. Each of these sub-stages is explained in more detail below: 3a) Calculation of the spatial phasor. Preferably, the voltage spatial phasor (^ ^^^) is obtained in the form of a complex space vector, from the instantaneous line voltages (^ ^^ , ^ ^^ ) by the following equation (I): The subscript "maq" that appears next to a magnitude in this equation and in the rest of the equations in this document refers to the fact that it is a magnitude corresponding to the electrical machine (in the present invention, the generator) that forms part of the wind turbine. The index "^" that appears in this equation and in the rest of the equations in this document refers to the fact that it is the imaginary part of the complex spatial vector. Preferably, the spatial current phasor (^ ^^^ ) is obtained in the form of a complex space vector, from the instantaneous line currents (^ ^ , ^ ^ , ^ ^ ) by the following equation (II): b) Calculation of the instantaneous velocity. Preferably, the instantaneous velocity of a spatial phasor in a sample ^ is obtained by the quotient of the angle difference between the time difference between sample ^ and the previous sample ^ − 1 of the spatial phasor; more preferably by the following equation (III): in which: - The symbol “^” refers to a k-th sample from a sequence of captured samples corresponding to a record. This clarification also applies to the remaining instances where the symbol “^” appears in this document, either in reference to this same equation (III) or to other equations. It is the instantaneous velocity of the spatial phasor of magnitude “x” in sample k; magnitude “x” may refer to voltage or current. - ^^^: refers to the mathematical function “argument”. - ^ ^^^ ( k ): is the spatial phasor of the magnitude “^” in a sample k; the magnitude “^” may refer to voltage or current, in coherence with the magnitude “x” referred to in - : is the complex conjugate of the spatial phasor of the magnitude “^” in sample k-1; the magnitude “^” may refer to voltage or current, in coherence with the magnitude “x” referred to in ω ^^^^ ( ^ ) . - Δ^: refers to the sampling time step between sample k and the previous sample k-1. c) calculation of the moving average of the instantaneous velocity of the spatial phasor. Preferably, the moving average of the instantaneous velocity of a spatial phasor is obtained by the following equation (IV): in which: is the moving average of the instantaneous velocity of the spatial phasor of the magnitude “x” for mm samples; the magnitude “x” may refer to voltage or current, depending on whether ω^ ^^^^ ( ^ ) refers to ω^^^^^ ( ^ ) ora ω ^^^^ ( ^ ) , respectively. - ^: refers to the summation index (summation notation expressed with the capital Greek letter sigma Σ). - + 1 − ^ ) : is the instantaneous velocity of the spatial phasor of the magnitude “x” corresponding to the sample ^ + 1 − ^; the magnitude “x” may be referred to voltage or current in coherence with the magnitude “x” referred to in Preferably, the moving average It is calculated for half the period of the signal. For example, according to the preferred implementation in which 36 samples are taken per period, the moving average It is calculated for 18 samples. d) Calculation of the transient discrimination coefficient. Preferably, the voltage transient discrimination coefficient and the transient current discrimination coefficient (^ ^^ ) are obtained by the following equation (V): in which: - ^ ^^: It is the transient discrimination coefficient of a magnitude “x” for a period with m samples in which m-mm moving averages are calculated; the magnitude “x” may refer to voltage or current, depending on whether ^ ^^ refers to ^ ^^ oa ^ ^^ , respectively. - The functions They return the maximum, minimum and average values, respectively, corresponding to the set of moving averages that are defined for the instantaneous velocity of the spatial phasor of the corresponding magnitude “x” over a complete sample record; the magnitude “x” may refer to voltage or current, in coherence with the magnitude “x” referred to in ^ ^^. Stage 3 can be carried out in various ways, such as according to the options explained below: - According to one option, in each sub-stage 3a-3d, calculations are performed to obtain the value of the corresponding voltage-related operating parameter, as well as the value of the corresponding current-related operating parameter, before continuing to the next stage. That is, in stage 3a, the voltage space phasor (^) is calculated ^^^ ) and the spatial current phasor (^ ^^^ ); subsequently, in step 3b the instantaneous velocity of the spatial voltage phasor is calculated and the instantaneous velocity of the current space phasor Next, in step 3c, the moving average of the instantaneous velocity of the spatial voltage phasor is calculated. and the moving average of the instantaneous velocity of the spatial current phasor and finally, in step 3d the transient voltage discrimination coefficient is calculated and the transient current discrimination coefficient (^ ^^ ). - According to another option, step 3 is performed once to calculate the parameters related to one of the quantities (voltage or current), and again to calculate the parameters related to the other of the quantities (current or voltage). That is, a cycle of steps 3a, 3b, 3c, 3d is performed to calculate the spatial voltage phasor (^ ^^^ ), the instantaneous velocity of the spatial voltage phasor the moving average of the instantaneous velocity of the spatial voltage phasor and the transient voltage discrimination coefficient (^ ^^ ), respectively; and another cycle of steps 3a, 3b, 3c, 3d is performed to calculate the spatial current phasor (^ ^^^ ), the instantaneous velocity of the current space phasor (ω ^^^^(^)), the moving average of the instantaneous velocity of the current spatial phasor and the current transient discrimination coefficient respectively. These two cycles can be performed one after the other or simultaneously. 4. Decision on whether to integrate the record into the operating map. Preferably, the record is discarded if it corresponds to an operating state with a high degree of transience (in the case of binary record stationarity, "high degree of transience" means false stationarity); otherwise, the record is accepted as valid information for forming the mini-wind turbine operating map (1). In this document, the term "valid record" will be used for simplified purposes to refer to the record accepted as valid information for forming the mini-wind turbine operating map (1). 5. Integration of the record into the operating map if it is a valid record.The valid record is integrated into the operating map as a recorded point, also referred to as a "point" for short. A point can be integrated into the operating map in a variety of ways, consistent with the operating map typology. For example, it can be graphically integrated into one or more coordinate graphs, it can be integrated into one or more tables of values, etc. According to a preferred embodiment, the operating map is represented in the form of one or more graphs that include values ​​for at least two of the following magnitudes of the valid record: frequency, magnitude of the complex space vector of voltage, magnitude of the complex space vector of current, and power. Preferably, the power value of a record that is integrated into the map corresponds to the average of the instantaneous powers in a sample ^ ^(^) for the samples that make up the record, ^(^) being obtained by the following equation (VI):. where: - the function ^^ returns the real part of the complex to which it is applied; - ^ ^^^ ( ^ ) : is the spatial phasor of stress in the sample ^; - ^ ∗ ^̅^^(^): is the complex conjugate of the spatial phasor of current in the sample ^. According to a more preferred embodiment, the performance map is made up of several two-dimensional graphs in which the values ​​of the following pairs of magnitudes are represented, in a related manner: - a two-dimensional graph with frequency values ​​and values ​​of the current complex space vector module; - a two-dimensional graph with frequency values ​​and values ​​of the voltage complex space vector module; - a two-dimensional graph with frequency values ​​and power values. Repeating steps 1 to 5 for new recordings. According to a preferred embodiment, for each recording, steps 1 to 5 are carried out according to the following particularities: The performance map is divided into nf frequency intervals between the minimum operating frequency and the maximum operating frequency.Preferably, all nf frequency intervals have the same amplitude in frequency. More preferably, the value of nf is the smallest positive integer that makes the amplitude of the frequency intervals, in percent of the minimum operating frequency, less than the lower of the transient discrimination thresholds (ℎ). ^^ , ℎ ^^). Preferably, the final operating map is made up of averaged information from the points recorded in each of nf intervals. The operation of mapping a valid record is performed by calculating a new average value for each of the calculated values ​​of the respective magnitudes under study of the record, for the frequency interval to which the record belongs, weighting it aliquotally with the points previously mapped in that interval. According to the preferred embodiment, each time a new valid record is integrated into the map, each of the mapping values ​​of the respective magnitudes is updated, for the interval to which it belongs; that is, the values ​​of the point recorded in the corresponding interval change their value to the new calculated values.Thus, according to the preferred embodiment, the final operating map includes at most one representative point for each interval; a representative point is understood to be the point recorded with the latest updated mapping values, which represents the operating conditions of the mini-wind turbine (1) in the corresponding interval. Preferably, the mapping value of a magnitude corresponding to a new valid record is an average value calculated using the following equation (VII): ( VII ) , in which: - ^ ^^,^^^ : is the updated mapping value corresponding to a magnitude ^ l, taking into account the new record, for the frequency interval ^^ to which the new record belongs; - ^: is the number of records that have contributed to the formation of the point recorded before the new record; - ^ ^^,^: is the mapping value corresponding to the magnitude ^ before the new record, for the frequency interval ^^ to which the new record belongs; - ^ ^: is the received value corresponding to the magnitude ^ of the new record. For example, let a given frequency interval ^^ be considered, which had previously received information from n previous records to form the previous average value, for that frequency interval ^^, of the following magnitudes ^: frequency, current vector modulus, voltage vector modulus and power. In this case, to map a new record, each of the respective average values ​​of frequency, current vector modulus, voltage vector modulus and power are updated, preferably using equation (VII). Therefore, in this case, each point on the map implicitly includes five values: the values ​​of the four magnitudes indicated plus the value corresponding to the number of records ^ that have previously contributed to the formation of the point on the map.According to a preferred embodiment, the process of mapping the operating conditions of a mini-wind turbine (1) is carried out in accordance with the following procedural conditions, as shown in Figure 1: - Once the mapping process is started, the first record received corresponding to a low transience state is always mapped, without waiting to receive more records. - From that first record onwards, each additional record corresponding to a low transience state is integrated or not into the map depending on the following options: a. If said additional record corresponds to an operating frequency range that has not yet received any mapped points, the point corresponding to the additional record is stored awaiting validation. b.If said additional record corresponds to an operating frequency range that has previously received a mapped point, the action to be taken depends on the consistency with the existing map: bi) If the point corresponding to the additional record does not deviate from the existing map, that point and all the previously stored points are mapped, each in its corresponding frequency range. According to a preferred embodiment, the condition for considering that a point does not deviate from the existing map is that the absolute value of the deviation is less than a deviation threshold; preferably, that the absolute value of the deviation is less than a deviation threshold simultaneously for all the magnitudes under study in the record, preferably, for the voltage vector module, the current vector module and for the power.Preferably, the deviation of a value corresponding to the voltage vector modulus, the current vector modulus, or the power is defined as the difference between the following two values: - the absolute percentage difference between the value of the magnitude of the point to be mapped and the previous mapped value of that magnitude in the corresponding frequency interval; and - the percentage frequency difference between the point to be mapped and the previous mapped frequency in that frequency interval. The value of the “deviation threshold” parameter is set according to the accuracy required for the operating condition map. Preferably, the deviation threshold is set as twice the highest of the established transient discrimination thresholds (ℎ. ^^ , ℎ ^^), multiplied by 100. Once the incorporation of the point and the previously stored points into the map is complete, if the map is complete, the mapping is terminated. Otherwise, the mapping continues. Preferably, the condition for considering the map complete is that the minimum number of records that have contributed to obtaining the mapping values ​​in each of all the frequency intervals is greater than or equal to nmin. The value of the parameter "nmin" is set based on the precision required for the operating map, as well as the amount of resources and time worth investing in the mapping. Preferably, the value of nmin is set to 3. b.ii) If the point in the additional record deviates from the existing map, the mapping is terminated.According to the preferred embodiment, the condition for considering that a recorded point deviates from the existing map is that the absolute value of the deviation is not less than the deviation threshold; preferably, that the absolute value of the deviation is not less than the deviation threshold for one of the magnitudes under study in the record, preferably for the voltage vector module, the current vector module or the power. Below are several examples of the method for mapping the operation of a mini-wind turbine (1), according to the present invention. Example 1: Operation mapping of a mini-wind turbine (1) in which the state of the mini-wind turbine does not change throughout the mapping process. Example 1 corresponds to a normal operating situation, in which the mapping is started and there is no degradation in the state of the mini-wind turbine (1) while the mapping process lasts.This would be the 'normal' situation when installing mapping equipment (2) on a newly installed mini-wind turbine (1) or one that has been in operation for an indefinite period, since typical degradation is progressive and develops relatively slowly. According to example 1, the following starting conditions are established: - The operating map is made up of the following two-dimensional graphs: ^ a two-dimensional graph with frequency values ​​f(Hz) / complex space vector module of current I(A); ^ a two-dimensional graph with frequency values ​​f(Hz) / complex space vector module of voltage U(V); ^ a two-dimensional graph with frequency values ​​f(Hz) / power P(W). - The voltage transient discrimination threshold (ℎ. ^^ ) is set to 0.05. - The current transient discrimination threshold (ℎ ^^) are set to 0.05. - The operating map is divided into 27 frequency intervals, as justified below: As a starting parameter, the value of nf is established as the smallest positive integer that makes the amplitude of the frequency intervals in percent of the minimum operating frequency less than the smallest of the transient discrimination thresholds (ℎ ^^ , ℎ ^^). The minimum operating frequency fmin is 24 Hz. The maximum operating frequency fmax is 56 Hz. According to the conditions established for nf: The lowest of the transient discrimination thresholds is 0.05. The maximum reference value for determining the width of the frequency intervals is 0.05 * 24 = 1.2. Then, the following circumstance must be met: (fmax – fmin) / nf < 1.2. The lowest positive integer for nf that meets this circumstance is 27, since in the case of 28 intervals: (56-24) / 28=1.1428; in the case of 27 intervals: (56-24) / 27=1.185; and in the case of 26 intervals: (56-24) / 26=1.2307. - The nmin parameter is set to 3. - A maximum of one representative point will be included in each frequency interval of the final operating map.- The condition for considering that a recorded point does not deviate from the existing map is that the absolute value of the deviation is less than a deviation threshold, simultaneously for the voltage vector module, the current vector module, and the power. The deviation of a value corresponding to the voltage vector module, the current vector module, or the power, is defined as the difference between the following two values: ^ the absolute percentage difference between the value of the corresponding magnitude at the point to be mapped and the previous mapped value of that magnitude in that frequency interval; and ^ the percentage frequency difference between the point to be mapped and the previous mapped frequency in that frequency interval. The value of the deviation threshold is set to twice the highest transient discrimination threshold expressed as a percentage; that is, 2 * 0.05 * 100 = 10.The process of mapping the operation of a mini-wind turbine (1) according to example 1 is developed as follows: 1. Reception of operating data from the mini-wind turbine (1). A record is received at an operating time of the mini-wind turbine (1). For this purpose, current and voltage values ​​of an electrical signal from the mini-wind turbine (1) are captured in the connection line between the mini-wind turbine (1) and the grid converter (5) (“electronic converter” in figure 16). The current and voltage values ​​are captured by means of a voltage sensor and a current sensor, respectively. The captured data are subjected to a previous analog adaptation stage and are digitalized.The digitization of the record is performed at a constant time step of 36 samples per period, until a total of 10 periods are completed (i.e., 360 samples are taken per record) with respect to the fundamental frequency of the current detected before the start of the recording. Figure 2 shows a graph with the digitized current and voltage values, corresponding to the captured record. In this figure, i1 is the line current R (also symbolized as i. R ), i2 is the line current S (also symbolized as i S ), v1 is the line voltage RS (also symbolized as u RS), v2 is the line voltage ST (also symbolized as uST), v3 is the line voltage TR (also symbolized as uTR). Being a three-wire line, the line current T used in the calculation of the space current vector with equation (II) is calculated as iT = -(iR+iS)). 2. Data filtering. During the digitization of stage 1, a certain level of noise in the digitized values ​​​​is inevitable (noise that appears even in the analog adaptation stage prior to digitization) that affects the values ​​​​of the quantities used to form the map. Furthermore, the type of electronic grid-link converter ("low voltage line" in figure 16) and the control used in it can introduce distortions with respect to the signals that would be obtained in operation with linear loads.To reduce the impact of noise on the digitization and the distortion introduced by the electronic converter, low-pass filtering (order 2, Butterworth equivalent) is applied at a cutoff frequency equal to twice the fundamental frequency. Since the sampling rate is fixed with respect to the fundamental frequency (36 times greater), the digital filtering coefficients are constant and do not depend on the fundamental frequency of the current. Figure 3 shows a graph with the current and voltage values ​​resulting from data filtering (i1zf, i2zf, v1zf, v2zf, v3zf). 3. Determining the stationarity of the record. The stationarity of the record is assessed by the current transient discrimination coefficient (^. ^^ ) and the transient voltage discrimination coefficient (^ ^^), whose values ​​are obtained using the equation V explained above. In the equation V, the symbol “x” refers to current or voltage, depending on whether the equation is used to calculate the current or voltage transient discrimination coefficient, respectively. The stationarity of the record is true if the current transient discrimination coefficient (^ ^^ ) is lower than the current transient discrimination threshold (ℎ ^^ ), and, in addition, the transient voltage discrimination coefficient (^ ^^ ) is lower than the voltage transient discrimination threshold (ℎ ^^ ). In this example, the value 0.05 is set for both ℎ ^^ as for ℎ ^^ . The following process is performed to calculate the value of the transient current discrimination coefficient (^ ^^ ): 3a) Calculation of the spatial current phasor (^ ^^^ ). The spatial current phasor (^ ^^^) is obtained in the form of a complex space vector, from the instantaneous line currents (^ ^ , ^ ^ ) using equation II explained above. From the expression obtained using equation II, the real and imaginary parts of the spatial current phasor are obtained, as well as its magnitude and argument. Figure 4 shows a graph with the values ​​corresponding to the real part (ia), imaginary part (ib), and magnitude (im) of the spatial current phasor. 3b) Calculation of the instantaneous velocity of the spatial current phasor ( ^ ) ). The instantaneous velocity of the current spatial phasor at each sample of the record (ω ^^^^ ( ^ )) is calculated using equation III explained above, where the symbols “x” and “^” refer to current. Equation III takes into account the difference in argument between consecutive samples; specifically between sample ^ and the previous sample ^ − 1. 3c) Calculation of the moving average of the instantaneous velocity of the spatial phasor of current The moving average of the instantaneous velocity of the spatial current phasor It is calculated using equation IV, for half a period of the signal; more specifically for 18 samples (as indicated above, in this example, data capture is performed at a constant time step of 36 samples per period). The symbol "x" in equation IV refers to current. Figure 5 shows a graph with the values ​​corresponding to the instantaneous velocity of the current space phasor (wimaq in Figure 5) and the moving average of the instantaneous velocity of the current space phasor (wimaqmm in Figure 5). 3d) Calculation of the current transient discrimination coefficient Equation V is applied, obtaining a value of ^ ^^ = 0.019. The following process is performed to calculate the value of the voltage transient discrimination coefficient (^ ^^ ): 3a) Calculation of the spatial voltage phasor (^ ^^^ ). The spatial voltage phasor (^ ^^^) is obtained in the form of a complex space vector, from the filtered instantaneous line voltages (^ ^^ = ^1^^, ^ ^^ = ^2^^), using equation I explained above. From the expression obtained using equation I, the real and imaginary parts of the spatial voltage phasor are obtained, as well as its magnitude and argument. Figure 6 shows a graph with the values ​​corresponding to the real part (va), imaginary part (vb), and magnitude (vm) of the spatial voltage phasor. 3b) Calculation of the instantaneous velocity of the spatial voltage phasor (ω ^^^^ ( ^ ) ). The instantaneous velocity of the spatial voltage phasor at each sample of the record (ω ^^^^(^)) is calculated using equation III explained above; the symbols “x” and “^” refer to voltage. Equation III takes into account the difference in argument between consecutive samples; specifically between sample ^ and the previous sample ^ − 1. 3c) Calculation of the moving average of the instantaneous velocity of the spatial voltage phasor The moving average of the instantaneous velocity of the spatial voltage phasor It is calculated using equation IV, for half a period of the signal; more specifically for 18 samples (as indicated above, in this example, data capture is performed at a constant time step of 36 samples per period). The symbol "x" in equation IV refers to voltage. Figure 7 shows a graph with the values ​​corresponding to the instantaneous velocity of the voltage space phasor (wumaq in Figure 7) and the moving average of the instantaneous velocity of the voltage space phasor (wumaqmm in Figure 7). 3d) Calculation of the voltage transient discrimination coefficient Equation V is applied, obtaining a value of ^ ^^ = 0.036. According to the calculated values ​​of the transient current discrimination coefficients and tension (^ ^^), the conditions are met for the record to be considered a record with true stationarity (or, in other words, a record with low transience), and are detailed below: The transient current discrimination coefficient (^ ^^ =0.019) is lower than the current transient discrimination threshold (ℎ ^^ =0.05), and, in addition, the transient voltage discrimination coefficient is lower than the voltage transient discrimination threshold (ℎ ^^=0.05). Decision on the integration of the record into the operation map. In this case, the conditions for the record to be considered a valid record are met (a record with low transience) and, therefore, it is accepted to form the operation map of the mini-wind turbine (1). As explained, Figures 2 to 7 show values ​​of magnitudes and parameters according to case A corresponding to a record with low transience, so it is considered a valid record to form the operation map of the mini-wind turbine (1). 5. Integration of the record into the operation map if it is a valid record. Since it is a valid record, it is integrated into the operation map as a recorded point.As can be seen in Figure 10, the recorded point is integrated into several two-dimensional graphs that reflect the values ​​of the following pairs of magnitudes: - a two-dimensional graph with values ​​of frequency f(Hz) / current complex space vector module I(A); - a two-dimensional graph with values ​​of frequency f(Hz) / voltage complex space vector module U(V); - a two-dimensional graph with values ​​of frequency f(Hz) / power P(W). The value of the power included in the two-dimensional graph “frequency f(Hz) / power P(W)” corresponds to the average of the instantaneous powers in a sample ^ (^(^)) for the samples that make up the record. ^(^) is calculated using the equation VI explained above. 6. Repeating steps 1 to 5 for new records.For each record, steps 1 to 5 are carried out, taking into account that each time a new valid record is integrated into the map, each of the respective average values ​​of frequency, current vector module, voltage vector module and power are updated by means of equation (VII). The record mapping process is governed by the procedural conditions explained above with reference to Figure 1. Figures 10 to 14 show the status of the operating map at different times of the mapping.At the top of each of these figures is an identifying name made up of two parts: a first part with the abbreviated term LL (referring to the word "full"), which reflects that the final map generated is complete (the final map is shown in Figure 14; the condition for considering the map complete is that the minimum number of records that have contributed to obtaining the mapping values ​​in each of all the frequency intervals is greater than or equal to 3); and a second part composed of the letter "R" (referring to the word "record") accompanied by a number, which indicates the record on which the method is being performed at the time shown in the figure. The process carried out to generate the operating map in Example 1 is explained below: - The mapping process begins.- A first record is captured (step 1), the obtained data are filtered (step 2), and the stationarity of the record is determined (step 3). Figures 2 to 9 show the results obtained in the different steps applied to the first captured record (record 1). As justified previously (step 4 of example 1), the first record in example 1 does not have high transience, so it is accepted as a valid record to form the operation map of the mini-wind turbine (1). - As this is the first valid record, it is mapped directly without waiting for new records (step 5). The corresponding mapping values ​​are shown in Figure 10. The membership interval of this first record is 29.63-30.81 Hz. - A new record is captured and the process is repeated to determine its transience.In this case, the new record (record 2) also does not have high transience, so it is accepted as a valid record to create the mini-wind turbine operation map (1). In this case, it is not the first valid record, so an analysis is made to see if the frequency interval to which this record belongs has previously received any mapped points. In this case, there are no previously recorded points in the range to which it belongs, so the point corresponding to the new record is stored. - The process is repeated again on new records. Figure 11 shows the status of the map once the method has been carried out on 26 records.In this case, the map does not change with respect to the map in record 1, either because the captured records have high transience and are not valid for forming the map, or because valid records have been captured but the respective membership intervals do not have previously mapped points, and, consequently, they have been stored awaiting validation. As an illustrative example, Figures 8 and 9 show magnitude and parameter values ​​for case B corresponding to a record in which, during its capture, there was a slight reduction in the rotation speed of the mini-wind turbine (1). This circumstance means that, in contrast to case A, the record in case B has high transience, since the transient current discrimination coefficient (^. ^^ =0.0688) is not lower than the current transient discrimination threshold (ℎ ^^=0.05), or the transient voltage discrimination coefficient (^ ^^ =0.072) is not lower than the voltage transient discrimination threshold (ℎ ^^ =0.05). Consequently, it is not considered a valid record and is therefore not included in the performance map. For simplification purposes, not all the values ​​obtained from Case B are provided in this case; only the instantaneous velocity of the current space phasor (wimaq in Figure 8), the moving average of the instantaneous velocity of the current space phasor (wimaqmm in Figure 8), and the transient current discrimination coefficient (^) are provided. ^^ in Figure 8), instantaneous velocity of the voltage space phasor (wumaq in Figure 9), moving average of the instantaneous velocity of the voltage space phasor (wumaqmm in Figure 9), voltage transient discrimination coefficient (^ ^^in Figure 9). - Figure 12 shows the status of the map once the method has been carried out on 51 records. At this point, the map consists of 22 recorded points corresponding to the respective frequency intervals. There are still 5 intervals on the map (32-33.18 Hz; 46.22-47.41 Hz; 48.89-50.07 Hz; 50.07-51.26 Hz; 54.81-56 Hz) that do not include recorded points. This is because, for those intervals, no records have yet been captured; no captured records are valid; or a valid record has been captured but has not yet been mapped because the respective recorded point is awaiting validation. Comparing Figure 12 with Figure 11, it can be seen that the mapping values ​​corresponding to the recorded point in the 29.63-30.81 Hz interval have been updated (the point in this interval has slightly changed its location on the map),and that more points recorded in other intervals are included. This is due to the following: At some point, a new record has been captured whose recorded point corresponds to an operating frequency interval that had previously received a mapped point; and the recorded point of the new record is not deviated from the existing map. At that moment, the point of the new record is mapped, as well as all the previously stored points, each in its respective frequency interval. This generates a "bump" filling process. A "bump" of this type is very noticeable at first because it is normal for it to take some time to receive a record again in an interval that has previously received a mapped point, since there is only one mapped point, the first one with low transience (which is always mapped). - Figure 13 shows the state of the map once the method has been carried out on 126 records. At this moment,The map is made up of 27 recorded points corresponding to respective frequency intervals; that is, all frequency intervals include respective recorded points. Comparing Figure 13 with Figure 12, it can be observed that the values ​​of multiple recorded points have been updated, and that points are included in the intervals that previously appeared empty. Although all intervals include respective recorded points, the condition for considering the map complete has not yet been met (i.e., the minimum number of records that have contributed to obtaining the mapping values ​​in each of all the frequency intervals is less than 3), so new records continue to be captured. - Figure 14 shows the state of the map once the method has been carried out on 197 records. At this point,All intervals include a representative point whose value is made up of the contribution of at least three records. Thus, the condition for considering the map complete is met and the mapping is completed; therefore, this figure corresponds to the final operating map of the mini-wind turbine (1). The final operating map of the mini-wind turbine (1) in Example 1 (also that of Example 2 shown below) is a 27x5 value matrix; that is, 5 values ​​for each representative point in each of the respective 27 intervals: one value corresponding to the number of records that contributed to obtaining the representative point, as well as the four mapped values ​​of the representative point corresponding to the frequency, the current vector module, the voltage vector module,and power. Figure 14 also includes a black line in each of the two-dimensional graphs. This line represents a theoretical operating map corresponding to the reference state, and is only included for reference purposes, to justify the validity of the method of the present invention. This theoretical map has been generated by taking the average with a number of records per point much higher than that usually taken into account. Due to the dispersion existing in the recorded data with respect to the reference state (inevitable in the measurement process on a real system) it can be seen that the map generated by each two-dimensional graph represents a slight dispersion with respect to the theoretical map corresponding to the reference state. Comparing Figure 14 with the rest of the figures (Figures 10 to 13), it can be observed that the aforementioned dispersion of the generated map is reduced as the map receives points,centering the generated map on the theoretical map represented by the black line. Example 2: Operational mapping of a mini-wind turbine (1) in which the state of the mini-wind turbine changes throughout the mapping. Unlike Example 1, Example 2 corresponds to a mapping process during which a progressive degradation in the state of the wind turbine has occurred. In Example 2, the starting conditions, process steps and procedural conditions of the mapping are the same as in Example 1, so, for simplification purposes, they are not included again in this document. Likewise, for simplification purposes, figures corresponding to different mapping times prior to the final map are not included; only Figure 15 is included, which corresponds to the final operation map of the mini-wind turbine (1), in which the effects derived from the state of the mini-wind turbine (1) changing throughout the mapping can be observed,as explained below. Similarly to Figures 10-14, the top part of Figure 15 includes an identifying designation consisting of two parts: a first part with the abbreviated term DESV (referring to the word “deviated”), which reflects that there is a degradation in the state of the wind turbine that introduces high deviations from the reference state; and a second part composed of the letter “R” (referring to the word “record”) accompanied by a number, which indicates the record on which the method is being performed at the time shown in the figure. As in Figure 14, Figure 15 includes a black line in each of the two-dimensional graphs, which represents a theoretical operating map corresponding to the reference state (this black line is only included for reference purposes,to justify the validity of the method of the present invention). As explained above with reference to Example 1, in Example 2 records are acquired and the different stages of the method are applied, such that the records are integrated into the map or not, depending on the mapping procedural conditions represented in Figure 1. Unlike Example 1, Example 2 corresponds to a mapping process during which a progressive degradation in the state of the wind turbine has occurred. Specifically, a progressive degradation has occurred from record 100,which has been detected in record 119. The degradation detection has been carried out by applying procedural condition b.ii). Specifically, the degradation has been detected because the deviation of the corresponding recorded point with respect to the previously mapped point in the corresponding interval exceeded the deviation threshold established in terms of the voltage vector module and the generated power. As shown in Figure 15, all intervals (27 intervals) include respective recorded points (27 recorded points), but the final map is not a complete map, since the conditions established for it are not met; that is, the minimum number of records that have contributed to obtaining the mapping values ​​in each of all the frequency intervals is less than 3. Under normal conditions (see example 1, in which the state of the mini-wind turbine does not change throughout the mapping),New records would continue to be captured until a complete map is obtained; however, in this case, having detected a degradation in the operation of the mini-wind turbine (1), the mapping is terminated. As a curiosity, it has been observed that in record 119 the degradation in terms of voltage vector module and generated power had reached 3.8% with respect to the reference state. This degradation is compatible, for example, with a demagnetization of the wind turbine's permanent magnets. Since the degradation of the wind turbine introduces high deviations with respect to the map generated up to that record, the algorithm detects this deviation and stops the mapping, in order to ensure that, from that moment on, there is a map that, although less precise (in Figure 15 it can be seen that the points of the map are more deviated from the reference state than in Figure 14), serves as a reference for comparison with future records (i.e.,the validity of the map is given priority over its completeness). Below are some comments on the benefits derived from the use of moving averages over half a period (these comments affect sub-stage 3c for both the calculation of the moving average of the instantaneous velocity of the current space phasor and the calculation of the moving average of the instantaneous velocity of the voltage space phasor): The distortion introduced by the converter (electronic converter in Figure 16) and, to a lesser extent, the noise captured in the acquired signal, cause the variability of the instantaneous frequency to be very high. The use of moving averages over half a period drastically reduces this variability because the most pronounced distortion in this type of signals corresponds to the 6th order harmonic and its multiples. Since half a period (the record section used to calculate the moving averages),contains exactly three periods of the 6th order harmonic (and a multiple of three periods of its multiples),Its influence on the moving average would be nullified in the theoretical case. In practice, this results in a very low variability of the moving average of the vector rotation speed in low transience situations, which can be observed by comparing the instantaneous speed with the moving average of the speed in the figures for case A (see figures 5 and 7) and case B (see figures 8 and 9). Another advantage of using moving averages compared to other types of filtering is that it causes the variability of the moving average to increase significantly in the face of progressive variations (slower than those associated with the fundamental component of the signal and the 6th order harmonics and their multiples mentioned above) due to the loss of synchronism between the capture step and the evolution of the signal: when the fundamental frequency (and the associated 6th order harmonics) changes within a record, a change in the half-period duration occurs.which no longer coincides with the time to capture the 18 samples used to calculate the moving averages and, as a consequence, the variability of the instantaneous vector velocity, which is almost completely eliminated when such synchronism does exist, is added to the base variability, giving rise to a total variability of the velocity calculated with the moving averages much higher than that corresponding to states with low transience. This variability can be clearly seen increasing in the right half of case B (see figures 8 and 9) while it barely exists in case A (see figures 5 and 7). A more conventional filtering system, such as a type IIR digital filter (similar to that used to filter instantaneous voltages and currents,in stage 2) with an attenuation similar to that achieved with filtering using moving averages, it would have a longer settling time of 18 samples (forcing the discarding of a larger set of samples at the beginning of the record) and, above all, it would be insensitive to the variability present in the moving averages, because the attenuation (associated with the frequency) would occur in a very similar proportion to that of the first half of the record of case B (see figures 8 and 9), due to the fact that the fundamental frequency undergoes a very slight progressive modification during this record of case B. The result is a very low transient discrimination coefficient for regimes with reduced transience, which allows the establishment of low transience thresholds. Establishing low transience thresholds allows, in turn, to discriminate and discard records even with a relatively low level of transience. The greater the transience, the greater the dispersion,for the same operating frequency, between the current, voltage and power values ​​corresponding to different records. As a result, being able to use low transience thresholds makes it possible to obtain operating maps with very low dispersion and which therefore define the reference state very precisely. According to a second aspect, the present invention also provides equipment (2) for mapping the operating conditions of mini-wind turbines, comprising programmable processing means (3), preferably a microcontroller, adapted to carry out the method according to the first aspect of the present invention. According to a preferred embodiment shown in Figure 16, the mapping equipment (2) also comprises: - a sensor means (4) consisting of a voltage sensor and a current sensor,intended for the following functions: Capturing voltage values ​​and current values ​​of electrical signals from a mini-wind turbine (1) under study, on a link line between the mini-wind turbine (1) and a grid converter (5); and transmitting the captured values ​​to the programmable processing means (3). - An AC-DC converter (6) between the mini-wind turbine (1) and the programmable processing means (3). The present invention also relates to a computer program with instructions which, when the program is executed on a computer, cause the computer to carry out the method according to the first aspect of the invention. The present invention also relates to a computer-readable data storage medium, comprising the computer program. Although the present invention has been described with reference to particular options and embodiments thereof,Those skilled in the art may make modifications and variations to the above teachings without departing from the scope and spirit of the present invention.

Claims

1. A computer-implemented method for mapping the operating conditions of mini-wind turbines, characterized in that it comprises the following actions: - records of the operation of a mini-wind turbine (1) are received, each record being made up of voltage and current values ​​from a series of samples of an electrical signal from the mini-wind turbine (1) at a respective moment of operation; - a map of the operating conditions of the mini-wind turbine (1) is formed with the received records, the records being integrated into the map in the form of recorded points, according to the following particularities: ^ any record that is not consistent with a reference state is discarded and, consequently, not integrated into the map,because it corresponds to a non-stationary operating state; the reference state being understood as the state of the mini-wind turbine (1) at the time the method is started; when a record is received that is consistent with the reference state, but is not consistent with the map formed up to that moment, the incorporation of new records into the map is stopped, and the mapping is terminated; it being understood that a record is not consistent with the map formed up to that moment when it deviates from said map by an amount equal to or greater than an established deviation threshold.

2. Method according to claim 1, wherein the operating records of the mini-wind turbine (1) are acquired by means of a sensor means (4) that captures voltage values ​​and current values.

3. Method according to any of the preceding claims, wherein each record includes 36 samples per period at a constant time step,4. Method according to any of the preceding claims, wherein the received records are subjected to digital filtering at a cut-off frequency equal to twice the fundamental frequency.

5. Method according to any of the preceding claims, wherein the operating conditions map is made up of values ​​corresponding to two or more electrical magnitudes, one of which is the frequency and the rest one or more of the following: voltage, current, power; taking into account the following particularities: - the voltage value of a record that is integrated into the map corresponds to the average, of the voltage spatial phasor module (^ ^^^ ) for the samples that make up the record, obtaining ^ ^^^ using the following equation: 1 1 ^ ^^^ = ( 2^ + ^ ) + ^ ^ (I) 3 ^^ ^^ √3 ^^ in which: ^ ^^ , ^ ^^are line voltages; - the current value of a record that is integrated into the map corresponds to the average of the current spatial phasor module (^ ^^^ ) for the samples that make up the record, obtaining ^ ^^^ using the following equation: in which: ^ ^ , ^ ^ , ^ ^ are instantaneous line currents; - the power value of a record that is integrated into the map corresponds to the average of the instantaneous powers in a sample ^ (^(^)) for the samples that make up the record, obtaining ^(^) by the following equation (VI): where: ^ the function ^^ returns the real part of the complex to which it is applied; ^ ^ ^^^ (^): is the spatial phasor of stress in the sample ^; ^ ^ ∗ ^̅^^(^): is the complex conjugate of the current space phasor in the sample ^.

6. Method according to claim 5, wherein the operating conditions map is made up of several two-dimensional graphs in which the values ​​of the following pairs of magnitudes are represented, in a related manner: - a two-dimensional graph with frequency values ​​and current space phasor module values; - a two-dimensional graph with frequency values ​​and voltage space phasor module values; - a two-dimensional graph with frequency values ​​and power values. 7.Method according to any of the preceding claims, wherein the operating conditions map is formed between a minimum frequency and a maximum operating frequency, according to the following particularities: - the map is divided into nf frequency intervals; - the record or records belonging to the same frequency interval are integrated into the map as a recorded point, whose values ​​of respective magnitudes, called "mapping values", are average values ​​of the record or records of said interval.

8. The method of claim 7, wherein all nf frequency intervals have the same amplitude in frequency.

9. The method of claim 8, wherein the value of nf is the smallest positive integer that causes the amplitude of the frequency intervals in percent of the minimum operating frequency to be less than the smallest of a set of transient discrimination thresholds, said thresholds being: a voltage transient discrimination threshold (ℎ), a voltage transient discrimination threshold (ℎ), and a voltage transient discrimination threshold (ℎ). ^^ ), and a current transient discrimination threshold (ℎ ^^ ).

10. Method according to any of claims 7 to 9, wherein the integration of a new record into the operating conditions map entails the updating of each of the mapping values ​​corresponding to the frequency interval to which the new record belongs, according to the following equation: (VII) in which: - ^ ^^,^^^: is the updated mapping value corresponding to a magnitude ^, taking into account the new record; - ^: is the number of records that have contributed to the formation of the recorded point before the new record; - is the mapping value corresponding to the magnitude ^ before the new record; - ^ ^: is the received value corresponding to the magnitude ^ of the new record.

11. Method according to any one of claims 7 to 10, comprising the following actions: - once mapping starts, the first stationary record is always mapped; - starting from that first stationary record, each additional stationary record is integrated or not into the map depending on the following options: a. if the additional stationary record corresponds to a frequency interval that has not yet received any mapped points: the point corresponding to the additional stationary record is stored awaiting validation; b. if the additional stationary record corresponds to a frequency interval that has previously received some mapped points, one of the following actions is performed, depending on the consistency of the record with the existing map: b.i) If the point corresponding to the additional stationary record is not deviated from the existing map, that point and all previous ones are mapped. stored, each in its corresponding frequency interval; and, once mapped, if the minimum number of records that have contributed to obtaining the mapping values ​​in each of all the frequency intervals is greater than or equal to a set minimum number (nmin), the mapping is terminated; b.ii) if the point corresponding to the additional stationary record is deviated from the existing map, the mapping is terminated.

12. Method according to claim 11, wherein the value of nmin is set to 3.

13. Method according to any of the preceding claims, wherein the stationarity of each record is determined by analyzing the series of samples that make up the record, comprising the following actions: - the voltage spatial phasor (^) is calculated ^^^) using the following equation: 1 1 ^ ^^^ = ( 2^ ^^ + ^ ^^ ) + ^ ^ (I) 3 √ 3 ^^ in which ^ ^^ , ^ ^^ are the line voltages; - the spatial current phasor is calculated (^ ^^^ ) using the following equation: in which ^ ^ , ^ ^ , ^ ^ are the instantaneous line currents; - the instantaneous velocity of the voltage space phasor is calculated and the instantaneous velocity of the current space phasor in each sample of the record, using the following equation: ( III ) where: ^ k refers to a k-th sample from the series of samples obtained corresponding to the record, ^ is the instantaneous velocity of the spatial phasor of magnitude x in sample k, the magnitude x being able to refer to voltage or current, depending on whether ω ^^^^ ( ^ ) refers to ω ^^^^ ( ^ ) ora ω ^^^^ ( ^ ) , respectively, ^ ^^^ refers to the mathematical function “argument”, ^ is the spatial phasor of the magnitude X in a sample k, the magnitude X being able to refer to voltage or current, in coherence with the magnitude x referred to in , ^ (k − 1) is the complex conjugate of the spatial phasor of the magnitude X in the sample k-1, the magnitude X being able to refer to voltage or current, in coherence with the magnitude x referred to in ω ^^^^ ( ^ ) ,^ Δ^ refers to the sampling time step between sample k and the previous sample k-1; - the moving average of the instantaneous velocity of the voltage space phasor is calculated, and the moving average of the instantaneous velocity of the current space phasor is calculated. using the following equation: in which: ^ ( ^ ) is the moving average of the instantaneous velocity of the spatial phasor of magnitude x for mm samples; magnitude x may refer to voltage or current, depending on whether ω^ ^^^^ ( ^ ) refers to ω^ ^^^^ ( ^ ) ora ω ^^^^ ( ^ ) , respectively, ^ ^ refers to the summation index, ^ ω ^^^^ ( ^ + 1 − ^ )is the instantaneous velocity of the spatial phasor of the magnitude x corresponding to the sample ^ + 1 − ^; the magnitude x can be referred to voltage or current in coherence with the magnitude x referred to in ( ^ ) ; - the transient voltage discrimination coefficient (^) is calculated ^^ ) and the transient current discrimination coefficient (^ ^^ ) using the following equation: in which: ^ ^ ^^ is the transient discrimination coefficient of a magnitude x for a period with m samples in which m-mm moving averages are calculated; the magnitude x may refer to voltage or current, depending on whether ^ ^^ refers to ^ ^^ oa ^ ^^ , respectively, ^ functions return the value maximum, minimum and average, respectively, corresponding to the set of moving averages that are defined for the instantaneous velocity of the spatial phasor of the corresponding magnitude x over a complete sample record; being able to refer the magnitude x to voltage or current, in coherence with the magnitude x referred to in ^ ^^ ; - the stationarity of the record is determined by comparing the calculated value of the voltage transient discrimination coefficient ( ^ ^^ ) with a voltage transient discrimination threshold established, and the calculated value of the transient current discrimination coefficient ( ^ ^^ ) with a current transient discrimination threshold (ℎ ^^ ) established.

14. The method of claim 13, wherein the moving average is calculated for half the period of the electrical signal.

15. Method according to any of claims 13 or 14, wherein the stationarity of the record is determined based on the following conditions: - a record is considered to be stationary only if the voltage transient discrimination coefficient is lower than the voltage transient discrimination threshold (ℎ ^^ ) and, in addition, the transient current discrimination coefficient is lower than the current transient discrimination threshold (ℎ ^^); - otherwise, the record is considered not to be stationary.

16. Method according to any of the preceding claims, wherein the condition for considering that a record deviates from the operating conditions map formed up to the time of obtaining the record is that the absolute value of the deviation of the corresponding recorded point is not less than the established deviation threshold, for one of the magnitudes under study.

17. Method according to claim 16, wherein the deviation of the recorded point, for one of the magnitudes under study, is defined as the difference between the following two values: - the absolute percentage difference between the value of the magnitude of the point to be mapped and the previous mapped value of that magnitude in the corresponding frequency interval; and - the percentage difference in frequency between the point to be mapped and the previous mapped frequency in the corresponding frequency interval. 18.Method according to any of the preceding claims, wherein the deviation threshold is set as twice the highest of established transient discrimination thresholds, multiplied by 100; said thresholds being: a voltage transient discrimination threshold (ℎ. ^^ ), and a transient discrimination threshold of current (ℎ ^^ 19. Method according to any of claims 9, 13, 15 or 18, wherein both the voltage transient discrimination threshold (ℎ ^^ ) as the current transient discrimination threshold (ℎ ^^) are set to 0.

05.

20. Equipment for mapping (2) the operating conditions of mini-wind turbines, characterized in that it comprises programmable processing means (3) adapted to carry out the method according to any of the preceding claims.

21. Mapping equipment (2) according to claim 20, comprising: - sensor means (4) intended for the following functions: ^ capturing voltage values ​​and current values ​​of electrical signals from a mini-wind turbine (1) under study; ^ transmitting the captured values ​​to the programmable processing means (3). - an AC-DC converter (6) between the mini-wind turbine (1) and the programmable processing means (3).

22. Mapping equipment (2) according to any of claims 20 to 21, comprising wireless communication means, giving access to the mapping results. 23.A computer program comprising instructions that, when the program is executed on a computer, cause the computer to carry out the method according to any one of claims 1 to 19. A computer-readable data storage medium comprising the computer program of claim 23.

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