Patent Application
20120271593
The present disclosure relates to monitoring wind turbine performance.
Wind turbines can be used to harvest energy from the wind. Many wind turbines operate in severe and/or remote environments, which may lead to deterioration of the components of the wind turbine and/or performance degradation of the wind turbine. Accordingly, wind turbines may need frequent maintenance in order to operate properly and effectively.
Maintenance of wind turbines may be performed on a scheduled basis (e.g., at a particular time interval and/or after a particular amount of operation time). However, such scheduled wind turbine maintenance may have low reliability and/or high costs. For example, the wind turbine may be operating properly and effectively (e.g., may not need maintenance) at the scheduled maintenance time, resulting in unnecessary maintenance being performed on the wind turbine at the scheduled maintenance time. As an additional example, if the wind turbine is not operating properly or effectively (e.g., needs maintenance), but the next scheduled maintenance will not occur for a long period of time, a large amount of production time may be lost before the next scheduled maintenance is performed.
Condition based maintenance of wind turbines can have a greater reliability and/or lower cost than scheduled maintenance. Previous condition based maintenance approaches may include, for example, monitoring the performance (e.g., power output) of a wind turbine, and comparing the performance of the wind turbine to an expected performance of the wind turbine. If the performance of the wind turbine deviates from its expected performance, maintenance may be performed.
However, in some instances, the deviation of the performance of the wind turbine from its expected performance may not be due to the wind turbine not operating properly or effectively. That is, the deviation may not be due to maintenance being needed by the wind turbine. Accordingly, such previous condition based maintenance approaches may also result in unnecessary maintenance being performed on the wind turbine.
Monitoring wind turbine performance is described herein. One or more device embodiments include a memory and a processor. The processor is configured to execute executable instructions stored in the memory to determine a number of power outputs of a wind turbine at a number of wind speeds, determine a number of power residuals of the wind turbine at the number of wind speeds based on the determined power outputs and an expected power output curve associated with the wind turbine, adjust the power residuals based on a number of characteristics associated with a location of the wind turbine, analyze performance of the wind turbine based on the adjusted power residuals, and generate and display a number of health indicators associated with the wind turbine.
Monitoring wind turbine performance in accordance with one or more embodiments of the present disclosure can be more reliable and/or less costly than previous scheduled maintenance approaches and previous condition based maintenance approaches. For example, monitoring wind turbine performance in accordance with one or more embodiments of the present disclosure may reduce and/or eliminate occurrences of unnecessary maintenance being performed on the wind turbine (e.g., may reduce and/or eliminate occurrences of maintenance being performed on the wind turbine when the wind turbine does not need maintenance). Additionally, monitoring wind turbine performance in accordance with one or more embodiments of the present disclosure may reduce the delay between when the wind turbine needs maintenance and when the maintenance is performed, thereby reducing the amount of production time that is lost before the maintenance is performed.
In the following detailed description, reference is made to the accompanying drawings that form a part hereof. The drawings show by way of illustration how one or more embodiments of the disclosure may be practiced. These embodiments are described in sufficient detail to enable those of ordinary skill in the art to practice one or more embodiments of this disclosure. It is to be understood that other embodiments may be utilized and that process, electrical, and/or structural changes may be made without departing from the scope of the present disclosure.
As will be appreciated, elements shown in the various embodiments herein can be added, exchanged, combined, and/or eliminated so as to provide a number of additional embodiments of the present disclosure. The proportion and the relative scale of the elements provided in the figures are intended to illustrate the embodiments of the present disclosure, and should not be taken in a limiting sense.
As used herein, “a” or “a number of” something can refer to one or more such things. For example, “a number of sensors” can refer to one or more sensors. Additionally, the designators “M” and “N” as used herein, particularly with respect to reference numerals in the drawings, indicate that a number of the particular feature so designated can be included with a number of embodiments of the present disclosure.
Wind turbines 110-1, 110-2, . . . , 110-M can be used to harvest energy from the wind at the location of the wind turbines (e.g., the site at which the wind turbines are installed). For example, wind turbines 110-1, 110-2, . . . 110-M can convert kinetic energy from the wind at the location of the wind turbines to electrical energy, as will be understood by one of ordinary skill in the art.
As shown in
Sensors 112-1, 112-2, . . . , 112-N can sense (e.g., detect, measure, collect, and/or record) supervisory control and data acquisition (SCADA) data associated with wind turbines 110-1, 110-2, . . . , 110-M. For example, sensors 112-1, 112-2, . . . , 112-N can sense wind speeds at the location of wind turbines 110-1, 110-2, . . . , 110-M, power outputs of the wind turbines (e.g., the amounts of power generated by the wind turbines) at the sensed wind speeds, speeds of the rotors of the wind turbines at the sensed wind speeds, temperatures of the gearboxes of the wind turbines, and/or temperatures and/or currents of the generators of the wind turbines, among other types of SCADA data.
Additionally, sensors 112-1, 112-2, . . . , 112-N can sense additional characteristics (e.g., additional data) associated with the location of wind turbines 110-1, 110-2, . . . , 110-M (e.g., operating conditions specific to the location of the wind turbines), such as, for instance, terrain and/or meteorological conditions associated with the wind turbines. For example, sensors 112-1, 112-2, . . . , 112-N can sense the air temperature at the location of wind turbines 110-1, 110-2, . . . , 110-M, the air pressure at the location of the wind turbines, the air density at the location of the wind turbines, the altitude of the location of the wind turbines, the wind direction of the wind at the location of the wind turbines, wind shear at the location of the wind turbines, turbulence intensity at the location of the wind turbines, and/or whether the terrain at the location of the wind turbines is complex or benign, among other types of operating conditions specific to the location of the wind turbines.
Sensors 112-1, 112-2, . . . , 112-N can send (e.g., transmit) the sensed data (e.g., the sensed SCADA data associated with the wind turbines and the sensed additional data associated with the location of the wind turbines) to computing device 120. That is, computing device 120 can receive the sensed data from sensors 112-1, 112-2, . . . , 112-N.
For example, sensors 112-1, 112-2, . . . , 112-N can send the sensed data to computing device 120 via a wired or wireless network (not shown in
A network may provide connections to the Internet and/or to the networks of other entities (e.g., organizations, institutions, etc.). Users may interact with network-enabled software applications to make a network request, such as to get a file or print on a network printer. Applications may also communicate with network management software, which can interact with network hardware to transmit information between devices on the network.
As shown in
Memory 124 can be volatile or nonvolatile memory. Memory 124 can also be removable, e.g., portable memory, or non-removable, e.g., internal memory. For example, memory 124 can be random access memory (RAM) and/or read-only memory (ROM) (e.g., dynamic random access memory (DRAM), electrically erasable programmable read-only memory (EEPROM), flash memory, phase change random access memory (PCRAM), compact-disk read-only memory (CD-ROM)), and/or a laser disk, a digital versatile disk (DVD) or other optical disk storage, and/or a magnetic medium such as magnetic cassettes, tapes, or disks, among other types of memory.
Further, although memory 124 is illustrated as being located in computing device 120, embodiments of the present disclosure are not so limited. For example, memory 124 can be located in a stand alone device and/or can be located internal to another computing resource, e.g., enabling computer readable instructions to be downloaded over the Internet or another type of wired or wireless connection.
Memory 124 can store executable instructions, such as, for example, computer readable instructions (e.g., software), for monitoring the performance of wind turbines 110-1, 110-2, . . . , 110-M (e.g., the performance of the components of the wind turbines and/or the efficiency with which the wind turbines convert wind kinetic energy to electrical energy) in accordance with one or more embodiments of the present disclosure. Processor 122 can execute the executable instructions stored in memory 124 to monitor the performance of wind turbines 110-1, 110-2, . . . , 110-M in accordance with one or more embodiments of the present disclosure. For example, processor 122 can execute the executable instructions stored in memory 124 to monitor the performance of wind turbines 110-1, 110-2, . . . , 110-M using the sensed data (e.g., the sensed SCADA data associated with the wind turbines and the sensed additional data associated with the location of the wind turbines) received from sensors 112-1, 112-2, . . . , 112-N by computing device 120 and an expected power output curve associated with the wind turbines, as will be further described herein (e.g., in connection with
As shown in
In some embodiments, computing device 120 can be located at the location (e.g., site) of wind turbines 110-1, 110-2, . . . , 110-M. That is, the instructions for monitoring the performance of wind turbines 110-1, 110-2, . . . , 110-M in accordance with one or more embodiments of the present disclosure can be deployed at the location of the wind turbines.
In some embodiments, computing device 120 can be located remotely from the location of wind turbines 110-1, 110-2, . . . , 110-M (e.g., at a different location than the wind turbines). That is, the instructions for monitoring the performance of wind turbines 110-1, 110-2, . . . , 110-M in accordance with one or more embodiments of the present disclosure can be deployed remotely from the location of the wind turbines.
At block 230, method 201 includes determining a number of power outputs of a wind turbine at a number of different wind speeds. The wind turbine can be, for example, one or more of wind turbines 110-1, 110-2, . . . , 110-M.
The number of power outputs of the wind turbine can be, for example, the amounts of power generated by the wind turbines at the number of different wind speeds. The power outputs can be sensed, for example, by sensors 112-1, 112-2, . . . , 112-N previously described in connection with
The power outputs of the wind turbine can be determined over a period of time, such as, for example, three months. For instance, the power outputs of the wind turbine can be determined during a season of the year. However, embodiments of the present disclosure are not limited to a particular period of time in which the power outputs of the wind turbine can be determined. For example, the period of time can be adjusted (e.g., the performance of the wind turbine over different time scales can be monitored). As an example, a longer period of time may allow long-term changes in the performance of the wind turbine (e.g., deterioration of the aerodynamic performance of the rotor blades of the wind turbine) to be monitored, while a shorter period of time may expose symptoms of an impending component failure of the wind turbine.
Further, the power outputs of the wind turbine can be determined at a particular interval during the period of time. For example, the power outputs of the wind turbine may be determined every minute, every ten minutes, or every hour. However, embodiments of the present disclosure are not limited to a particular interval. The interval may depend on, for example, the power output capability of the wind turbine (e.g., the more power the wind turbine can generate, the smaller the interval may be).
At block 232, method 201 includes determining a number of power residuals of the wind turbine at the number of wind speeds based on (e.g. by comparing) the determined power outputs and a pre-determined expected power output curve associated with the wind turbine. The pre determined expected (e.g., nominal) power output curve can be an indicator of the expected performance of the wind turbine at different wind speeds and a particular air density. That is, the pre-determined expected power output curve can be based on (e.g., determined using) a number of expected power outputs associated with the wind turbine at a number of wind speeds and a particular air density, and different points along the curve can provide the expected power output of the wind turbine at different wind speeds and the particular air density.
The pre-determined expected power output curve can be a performance specification provided by the manufacturer of the wind turbine. For example, for specific wind turbine operation, power curves can be derived from non-dimensional power coefficient versus tip speed ratio performance curves of the wind turbine design, and can be established by the wind turbine manufacturer following published guidelines of power performance measurements of electricity producing wind turbines. The power curve can be used to estimate the average energy production at a particular location for a given Rayleigh wind profile and to monitor the power production performance of installed wind turbines.
The pre-determined expected power output curve can be for an operational wind speed range that is between the cut-in speed and the cut-out speed of the wind turbine. The cut-in speed is the wind speed at which the wind turbine begins to generate power, and the cut-out speed is chosen to protect the wind turbine from high loads.
The number of power residuals of the wind turbine at the number of wind speeds can be determined, for example, by subtracting the expected power output of the wind turbine at the number of wind speeds from the determined power outputs of the wind turbine at the number of wind speeds. That is, the number of power residuals can be the difference between the determined power outputs and the expected power outputs (e.g., the deviation of the determined power outputs from the expected power outputs). For example, the power residual of the wind turbine at a particular wind speed can be the difference between the determined power output of the wind turbine at the particular wind speed and the expected power output of the wind turbine at the particular wind speed provided by the pre-determined expected power output curve associated with the wind turbine.
The pre-determined expected power output curve, however, may not account for characteristics associated with the location of the wind turbine (e.g., operating conditions specific to the location of the wind turbines) and/or changes in the condition of the components of the wind turbine. That is, the actual power output of the wind turbine may deviate from the expected power output curve due to characteristics associated with the location of the wind turbine and/or changes in the condition of the components of the wind turbine. Accordingly, at block 234, method 201 includes adjusting the power residuals based on (e.g., to account for) a number of characteristics associated with (e.g., operating conditions specific to) a location of the wind turbine.
The number of characteristics associated with the location of the wind turbine can include, for example, terrain and/or meteorological conditions associated with the wind turbine, such as the air temperature at the location of wind turbine, the air pressure at the location of the wind turbine, the air density at the location of the wind turbine, the altitude of the location of the wind turbine, the wind direction of the wind at the location of the wind turbine, wind shear at the location of the wind turbine, turbulence intensity at the location of the wind turbine, and/or whether the terrain at the location of the wind turbine is complex or benign, among other types of operating conditions specific to the location of the wind turbine. The characteristics associated with the location of the wind turbine can be sensed, for example, by sensors 112-1, 112-2, . . . , 112-N previously described in connection with
In some embodiments, adjusting the power residuals based on the number of characteristics associated with the location of the wind turbine can include, for example, assigning each power residual to one of a number of data bins (e.g., determining the power residuals for each bin), and determining statistics (e.g., the mean and/or variance) associated with each of the data bins. Each data bin can have a boundary based on wind speed and/or a baseline variation boundary (e.g., a nominal operational boundary that is a multiple of the standard deviation for that bin in baseline data). For example, an n-sigma boundary can indicate the variability of the power residuals in each data bin, which can provide a characterization of the shape of the power residual curve. This can form the basis for generating condition indicators that can separate nominal operation from faulty or deteriorated operation. Such condition indicators will be further described herein.
At block 236, method 201 includes analyzing performance of the wind turbine based on the adjusted power residuals. The performance analysis of the wind turbine can include, for example, determining whether the performance of the wind turbine is degrading (e.g., whether the efficiency with which the wind turbine converts wind kinetic energy to electrical energy is decreasing) and/or whether the performance of the components of the wind turbine is degrading (e.g., whether one or more components of the wind turbine are failing or about to fail). For instance, the performance analysis of the wind turbine can determine that blade aerodynamic degradation is occurring (e.g., due to leading and/or trailing edge losses and/or dirt and/or ice buildup on the blades), power loss is occurring (e.g., due to drivetrain misalignment and/or friction caused by bearing and/or gear faults), pitch control system degradation is occurring, and/or the gear box of the wind turbine is failing, among other types of degradation.
The performance of the wind turbine can be analyzed by, for example, performing a statistical analysis of the adjusted power residuals. The statistical analysis can include, for instance, determining an average (e.g., mean) adjusted power residual at each of the number of wind speeds (e.g., for each wind speed data bin), determining a standard deviation associated with the adjusted power residuals at each of the number of wind speeds, determining a skewness associated with the adjusted power residuals at each of the number of wind speeds, and/or determining a kurtosis associated with the adjusted power residuals at each of the number of wind speeds. The skewness can provide a measure of distribution symmetry for each wind speed bin, and the kurtosis can provide a measure of the shape of the distribution for each distribution bin (e.g., of how peaked or flat each distribution bin is).
The performance analysis of the wind turbine can include generating a number of condition indicators and/or health indicators. The condition indicators can be a measure(s) of the state of the wind turbine, and the health indicators can be a decision and/or conclusion based on the condition indicators. The condition indicators can graphically (e.g., numerically) represent the performance of the wind turbine. For example, the condition indicators can be a graphical representation(s) of the statistical analysis performed on the adjusted power residuals. The health indicators can describe the performance of the wind turbine in words to associated the wind turbine health with Normal or Abnormal (e.g., Anomaly), or to isolate the condition to one or more failure modes. For example, if the statistical analysis performed on the adjusted power residuals indicates the gear box of the wind turbine is failing, the health indicator can be “gear box failure”. Health indicators can further post-process the condition indicators and their historical trend to make a decision on the health. For example, if one or more condition indicators have been trending higher or lower than normal, a health indicator may take the history and interaction among condition indicators to make a conclusion of failure or normality.
As an example, in some instances (e.g., when many years of data is not available), the average adjusted power residuals may provide an indication of an anomaly, but may not be able to indicate whether the anomaly can be explained by (e.g., is due to) seasonal variations.
However, in such instances, the skewness and/or kurtosis associated with the adjusted power residuals may be able to indicate whether the anomaly is due to seasonal variations and not performance degradation. For example, the skewness and/or kurtosis may indicate that the anomaly is not due to seasonal variations (e.g. is due to performance degradation) if they include small variations between seasonal (e.g., quarterly) data sets that are dominated by the indicator curve for the quarter with the failure.
Such an analysis example may be based on lumped data for certain quarters. Diagnostics and/or prognostics may depend on the sensor measurements. For instance, exclusive sensor measurements for particular failure modes can provide more accurate and/or earlier warnings of the failure. Such deviations can be detected by, for example, performing a similar analysis for moving windows having a duration of 30 days, with one day progression intervals. In such an example, the skewness and/or kurtosis associated with the adjusted power residuals in each wind speed bin can provide the approximate day (e.g., a three day window) when the deviation has begun.
At block 238, method 201 includes providing the performance analysis to a user. For example, the number of condition indicators and/or health indicators can be provided to the user. The user can be, for example, a user of computing device 120, and the performance analysis can be provided (e.g., displayed and/or presented) to the user via user interface 126 previously described in connection with
At block 350, method 302 includes determining an expected power output curve associated with a wind turbine. The wind turbine can be, for example, one or more of wind turbines 110-1, 110-2, . . . , 110-M. In the embodiment illustrated in
The determined expected (e.g., nominal) power output curve can be an indicator of the expected performance of the wind turbine at different wind speeds and a particular air density. That is, is the determined expected power output curve can be based on (e.g., determined using) a number of expected power outputs associated with the wind turbine at a number of wind speeds and a particular air density, and different points along the curve can provide the expected power output of the wind turbine at different wind speeds and the particular air density. Further, the determined expected power output curve can be for an operational wind speed range that is between the cut-in speed and the cut-out speed of the wind turbine.
The expected power output curve can be determined by, for example, determining a number of power outputs of the wind turbine (e.g., the amounts of power generated by the wind turbine) at a number of wind speeds over a period of time during which the wind turbine is known to be performing normally (e.g., operating within expected performance parameters and/or generating an expected amount of power), and determining the expected power output curve based on the determined power outputs of the wind turbine over the period of time.
The determined power outputs of the wind turbine can be, for example, part of the SCADA data sensed by sensors 112-1, 112-2, . . . , 112-N previously described in connection with
In addition to wind speed, the power output of the wind turbine can also additionally depend on the air mass at the location of the turbine. Accordingly, in addition to wind speed, the expected power output curve may also be additionally based on (e.g., determined using) the air density at the location of the wind turbine. For example, the expected power output curve may be based on an expected power output of the wind turbine at a number of wind speeds and the air density at the location of the turbine. That is, a family of expected power output curves may be determined for different air densities.
The air density at the location of the turbine can be given by:
ρ=p/RT
where ρ is the air density at the location of the wind turbine in kg/m3, p is the air pressure at the location of the wind turbine in N/m2, R is the specific gas constant (287 J/kgK), and T is the air temperature at the location of the wind turbine in Kelvins. Accordingly, determining the expected power output curve can include determining an expected power output of the wind turbine at a number of wind speeds based, at least in part, on the air pressure at the location of the air turbine and the air temperature at the location of the wind turbine.
Additionally and/or alternatively, the air density at the location of the turbine can be given by:
ρ=(ρo/RT)exp(gz/RT)
where ρ is the air density at the location of the wind turbine in kg/m3, ρo is the standard sea level atmospheric pressure, R is the specific gas constant (287 J/kgK), T is the air temperature at the location of the wind turbine in Kelvins, and z is the elevation (e.g., altitude) of the location of the wind turbine in meters. Accordingly, determining the expected power output curve can include determining an expected power output of the wind turbine at a number of wind speeds based, at least in part, on the air temperature at the location of the wind turbine and the elevation of the location of the wind turbine.
At block 352, method 302 includes determining a number of power outputs of the wind turbine at a number of different wind speeds. Block 352 can be analogous to block 230 of method 201 previously described herein in connection with
At block 354, method 302 includes determining a number of power residuals of the wind turbine at the number of wind speeds by comparing the determined power outputs to the determined power output curve. The number of power residuals of the wind turbine at the number of wind speeds can be determined, for example, by subtracting the expected power output of the wind turbine at the number of wind speeds from the determined power outputs of the wind turbine at the number of wind speeds. That is, the number of power residuals can be the difference between the determined power outputs and the expected power outputs (e.g., the deviation of the determined power outputs from the expected power outputs). For example, the power residual of the wind turbine at a particular wind speed can be the difference between the determined power output of the wind turbine at the particular wind speed and the expected power output of the wind turbine at the particular wind speed provided by the determined expected power output curve associated with the wind turbine.
The determined expected power output curve, however, may not account for characteristics associated with the location of the wind turbine (e.g., operating conditions specific to the location of the wind turbines) and/or changes in the condition of the components of the wind turbine. That is, the actual power output of the wind turbine may deviate from the expected power output curve due to characteristics associated with the location of the wind turbine and/or changes in the condition of the components of the wind turbine.
Accordingly, at block 356, method 302 includes adjusting the power residuals to account for a number of characteristics associated with (e.g., operating conditions specific to) a location of the wind turbine. Block 356 can be analogous to block 234 of method 201 previously described herein in connection with
At block 358, method 302 includes analyzing performance of the wind turbine based on the adjusted power residuals, and at block 360 method 302 includes providing the performance analysis to a user. Blocks 358 and 360 can be analogous to blocks 236 and 238, respectively, of method 201 previously described in connection with
Although specific embodiments have been illustrated and described herein, those of ordinary skill in the art will appreciate that any arrangement calculated to achieve the same techniques can be substituted for the specific embodiments shown. This disclosure is intended to cover any and all adaptations or variations of various embodiments of the disclosure.
It is to be understood that the above description has been made in an illustrative fashion, and not a restrictive one. Combination of the above embodiments, and other embodiments not specifically described herein will be apparent to those of skill in the art upon reviewing the above description.
The scope of the various embodiments of the disclosure includes any other applications in which the above structures and methods are used. Therefore, the scope of various embodiments of the disclosure should be determined with reference to the appended claims, along with the full range of equivalents to which such claims are entitled.
In the foregoing Detailed Description, various features are grouped together in example embodiments illustrated in the figures for the purpose of streamlining the disclosure. This method of disclosure is not to be interpreted as reflecting an intention that the embodiments of the disclosure require more features than are expressly recited in each claim.
Rather, as the following claims reflect, inventive subject matter lies in less than all features of a single disclosed embodiment. Thus, the following claims are hereby incorporated into the Detailed Description, with each claim standing on its own as a separate embodiment.
The subject matter of this disclosure was made with government support under Contract Number DE-EE0001368 awarded by the US Department of Energy. Accordingly, the U.S. Government has certain rights to subject matter disclosed herein.
