System and method for controlling a power generation facility

Abstract

Systems and methods for controlling a power generation facility are provided. Thus, a facility-level controller determines a reactive power transfer coefficient for each power generation asset of the power generation facility. The reactive power transfer coefficient includes at least one of a reactive power generation coefficient and a reactive power transmission coefficient. The reactive power transfer coefficient represents the impact on the active power generation capability of each power generation asset in the power generation assets due to a change in the amount of reactive power transferred to an interconnection point. At least partially based on the reactive power transfer coefficient, the facility-level controller determines a portion of a demand signal to be met by each power generation asset in the power generation assets.

Description

Technical Field

[0001] This disclosure generally relates to power generation facilities, and more particularly to systems and methods for controlling power generation facilities having multiple power generation assets. Background Technology

[0002] Renewable energy is considered one of the cleanest and most environmentally friendly energy sources available today, and power generation facilities that include renewable energy assets are receiving increasing attention in this regard. An example of such a renewable energy asset is the wind turbine. A modern wind turbine typically comprises a tower, a generator, a gearbox, a nacelle, and one or more rotor blades. The nacelle includes a rotor assembly coupled to the gearbox and to the generator. The rotor assembly and gearbox are mounted on a base support frame located within the nacelle. One or more rotor blades capture the kinetic energy of the wind using known airfoil principles. The rotor blades transfer this kinetic energy as rotational energy to rotate a shaft that couples the rotor blades to the gearbox, or, if no gearbox is used, directly couples the rotor blades to the generator. The generator then converts the mechanical energy into electrical energy, which can be transmitted to a converter and / or transformer housed within the tower and subsequently deployed to the public power grid. Modern wind power systems typically take the form of wind farms with multiple such wind turbine generators operable to power transmission systems that supply electricity to the grid.

[0003] Modern power grid regulations often require power generation facilities (such as wind farms) to produce a certain amount of reactive power when requested by the grid. Depending on the operating status of each power generation asset (such as a wind turbine), an increase of one unit of reactive power can lead to a decrease in the active power generated by that asset. Since active power is the component of power that is typically sold to the grid by the power generation facility, it is often desirable to limit the reduction in active power generation.

[0004] Furthermore, modern renewable energy generation facilities can comprise more than one hundred generating assets managed at a single point of interest (POI) connected to the grid. To maximize power generation, these assets are typically distributed over large areas of land. However, a drawback of such an arrangement is that a significant portion of the power generated by the generating assets may be lost during transmission as the current travels the distance from the assets to the POI. These losses can result in a significant difference between the amount of power generated by the assets and the amount delivered to the grid. Thus, it is generally desirable to limit the power losses caused by the distance the generated power must travel to reach the POI.

[0005] Modern renewable energy generation assets are typically arranged along feeders. This arrangement often results in voltage tiering effects on assets at the ends of the feeders. Voltage tiering occurs when assets along the same feeder recursively increase or decrease the voltage of adjacent assets due to reactive power injection or absorption. This voltage increase / decrease causes assets at the ends of the feeder to spend most of their lifespan operating at higher or lower voltages when injecting or absorbing reactive power. In other words, voltage tiering can force assets farther from the point of origin (POI) to operate at non-nominal voltages, reducing their lifespan. Limiting or mitigating the effects of voltage tiering on assets furthest from the POI is often desirable.

[0006] Therefore, the art is constantly seeking new and improved systems to control power generation facilities and adjust reactive power generation demand to minimize the impact on active power generation capacity. Accordingly, this disclosure relates to systems and methods for controlling power generation facilities to establish reactive power setpoint commands for each power generation asset based on the reactive power transfer factor of each asset in the power generation asset portfolio. Summary of the Invention

[0007] The aspects and advantages of the invention will be set forth in part in the description which follows, or may be obvious from the description, or may become apparent by practice of the invention.

[0008] In one aspect, this disclosure relates to a method for controlling a power generation facility connected to a power grid. The power generation facility may have multiple power generation assets. The method may include receiving a demand signal from the power grid using a facility-level controller of the power generation facility. The method may also include using the facility-level controller to determine a reactive power transfer factor for each of the power generation assets. The reactive power transfer factor may include at least one of a reactive power generation factor and a reactive power transfer factor. The reactive power transfer factor may represent the impact on the active power generation capacity of each of the power generation assets due to changes in the amount of reactive power transferred to the interconnection point (POI) of the power generation facility. Additionally, the method may include using the facility-level controller to determine a portion of the reactive power demand signal to be satisfied by each of the multiple power generation assets based on the reactive power transfer factor of each of the power generation assets. The portion of the reactive power demand signal satisfied by at least one power generation asset may be greater than the portion satisfied by at least one other power generation asset. The method may also include using the facility-level controller to generate a setpoint command for each of the power generation assets. In addition, the method may include transmitting setpoint commands to each of the multiple power generation assets in order to control the reactive power output of each of the multiple power generation assets.

[0009] In an embodiment, determining which portion of the reactive power demand signal should be satisfied by each of the multiple generation assets may further include ranking the reactive power transfer coefficients of each of the generation assets using a facility-level controller. A higher reactive power transfer coefficient can indicate a greater impact on the active power generation capacity of one of the generation assets compared to a lower reactive power transfer coefficient of another of the multiple generation assets. The distribution of said portions of the reactive power demand signal may be based on this ranking.

[0010] In an additional embodiment, determining the reactive power transfer factor may include using a facility-level controller to determine the reactive power transfer factor for each of the generating assets. The reactive power transfer factor may represent the ability of each generating asset to transfer reactive power to the POI. The reactive power transfer factor may be based at least in part on the distance between each generating asset and the POI.

[0011] In another embodiment, determining the reactive power transfer factor may include using a facility-level controller to combine the POI impedance of the generating facility with the dynamic transfer efficiency of each generating asset within the generating assets. The transfer efficiency may correspond to the ability of each generating asset to transfer reactive power to the POI at a given power setpoint.

[0012] In another embodiment, multiple power generation assets can be divided into multiple asset groups. Each asset group can be coupled to a corresponding feeder for series coupling to the POI. The method may also include receiving an indication of the operating status of each power generation asset using a facility-level controller. The operating status may include the active power generation, reactive power generation, voltage setpoint, and operating temperature of each power generation asset. The method may also include determining the dynamic transmission efficiency of each power generation asset using the facility-level controller based on the operating status of each power generation asset within each asset group and the position of each power generation asset within each asset group relative to the POI.

[0013] In an embodiment, determining the reactive power transfer factor may include using a controller to determine the operating state of each power generation asset. The operating state may include the active power generation, reactive power generation, voltage setpoint, and operating temperature of each power generation asset. The method may also include using the controller to determine the reactive power generation factor of each power generation asset. The reactive power generation factor may represent, in kilowatts, the reduction in active power generation capacity of each power generation asset for every unit increase in reactive power generation under the determined operating state.

[0014] In an additional embodiment, determining the reactive power transfer factor may include using a facility-level controller to determine the reactive power transfer factor for each of the generating assets. The reactive power transfer factor may represent the ability of each generating asset to transfer reactive power to the POI. The reactive power transfer factor may be based at least in part on the distance between each generating asset and the POI. The method may also include calculating the reactive power transfer factor by combining the reactive power generation factor and the reactive power transfer factor using a facility-level controller.

[0015] In another embodiment, the operating state may be an operating state configured to maximize power generation, and determining the reactive power generation factor may include modeling an incremental cost in kilowatts using a controller, the incremental cost corresponding to the reduction in active power generation capacity required for an increase in the amount of reactive power generated in the operating state. The reactive power generation factor may be equal to the incremental cost in kilowatts for each additional unit of reactive power.

[0016] In another embodiment, the operating state may be configured to limit power generation, and determining the reactive power generation factor may include using a controller to determine a source energy level sufficient to support an increased power generation amount for at least one of the power generation assets. The increased power generation amount may be below an asset threshold. The increased power generation amount may include an increase in reactive power generation while active power generation remains constant. Active power generation may result in a reactive power generation factor of zero.

[0017] In an additional embodiment, the operating state may be an operating state configured to limit power generation, and determining the reactive power generation factor may include using a controller to determine a source energy level sufficient to support an increased power generation of at least one of the power generation assets. The method may also include using a controller to determine a first portion of the increase in reactive power generation satisfied by the increased power generation without exceeding an asset threshold. The method may further include using a controller to model an incremental cost in kilowatts, the incremental cost corresponding to a reduction in active power generation capacity required by a second portion of the increased reactive power generation. The reactive power generation factor may be equal to the incremental cost in kilowatts for each additional unit of reactive power not satisfied by the increased power generation.

[0018] In this embodiment, the power generation facility may include a wind farm and multiple power generation assets may include multiple wind turbines.

[0019] In an additional embodiment, multiple power generation assets may include multiple substations of the power generation facility.

[0020] In another aspect, this disclosure relates to a system for controlling a power generation facility. The system may include multiple power generation assets coupled to a power grid. The system may also include a facility-level controller communicatively coupled to the multiple power generation assets and coupled to the power grid. The facility-level controller may include at least one processor configured to perform multiple operations. The multiple operations may include receiving a reactive power demand signal from the power grid. The operations may also include determining a reactive power transfer factor for each of the power generation assets, the reactive power transfer factor including at least one of a reactive power generation factor and a reactive power transmission factor. The reactive power transfer factor may represent the impact on the active power generation capacity of each of the power generation assets due to an increase in the amount of reactive power transferred to the POI of the power generation facility. Additionally, the operations may include determining a portion of the reactive power demand signal to be satisfied by each of the multiple power generation assets based on the reactive power transfer factor of each of the power generation assets. The portion of the reactive power demand signal satisfied by at least one power generation asset is greater than the portion satisfied by at least one other power generation asset. The operations may also include generating a reactive power setpoint command for each of the power generation assets. Furthermore, the operation may include transmitting reactive power setpoint commands to each of the multiple generating assets to control the reactive power output of each of the multiple generating assets. It should be understood that the system may further include any additional steps and / or features described herein.

[0021] These and other features, aspects, and advantages of the invention will be better understood by referring to the following description and the appended claims. The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention. Attached Figure Description

[0022] The complete and enabling disclosure of the invention, including its best mode, is set forth in the description with reference to the accompanying drawings, for those skilled in the art, wherein:

[0023] Figure 1 A perspective view illustrating one embodiment of a power generation asset according to this disclosure is provided;

[0024] Figure 2 A schematic diagram illustrating one embodiment of a power generation facility configured as a wind farm having multiple wind turbines, according to the present disclosure;

[0025] Figure 3 This describes the asset groups that are coupled in series to the corresponding feeders according to the specific description in this disclosure. Figure 2 A schematic diagram of a portion of the power generation facilities;

[0026] Figure 4This describes the hybrid power generation facility configured according to this disclosure. Figure 2 A schematic diagram of an embodiment of a power generation facility;

[0027] Figure 5 This explains the relationship between this disclosure and... Figure 2 A schematic diagram of one embodiment of a controller used in conjunction with power generation facilities is shown in the figure;

[0028] Figure 6 A schematic diagram illustrating an embodiment of the control logic of a system for operating a power generation facility according to the present disclosure is shown.

[0029] Figure 7 This explains the provisions of this disclosure. Figure 6 Part of the control logic; and

[0030] Figure 8 This disclosure illustrates the power curves related to the source energy level used for power generation assets.

[0031] The repeated use of reference numerals in this specification and figures is intended to represent the same or similar features or elements in this invention. Detailed Implementation

[0032] Reference will now be made in detail to embodiments of the invention, one or more examples of which are illustrated in the figures. Each example is provided by way of explanation rather than limitation of the invention. Indeed, it will be apparent to those skilled in the art that various modifications and variations may be made to the invention without departing from the scope or spirit thereof. For example, features described or illustrated as part of one embodiment may be used with another embodiment to produce yet another embodiment. Therefore, it is intended that the invention cover such modifications and variations as included within the scope of the appended claims and their equivalents.

[0033] As used herein, the terms “first,” “second,” and “third” may be used interchangeably to distinguish one component from another, and the terms “first,” “second,” and “third” are not intended to indicate the position or importance of the individual components.

[0034] Unless otherwise stated herein, the terms “coupled,” “fixed,” “attached to,” etc., refer to direct coupling, fixing, or attachment, as well as indirect coupling, fixing, or attachment through one or more intermediate components or features.

[0035] As used throughout the specification and claims, approximate language is applied to modify any quantitative representation that may allow variation without causing a change in the essential function associated with it. Therefore, values ​​modified by one or more terms such as “approximately,” “about,” or “substantially” are not limited to specified precise values. In at least some cases, approximate language may correspond to the precision of the instrument used to measure the value or to the precision of the method or machine used to construct or manufacture the part and / or system. For example, approximate language may refer to a margin of error of 10%.

[0036] Unless the context or language otherwise indicates, scope limitations are combined and interchanged herein and throughout the specification and claims, and such scope is identified and includes all subscopes contained herein. For example, all scopes disclosed herein include endpoints, and endpoints are independently combinable with each other.

[0037] Generally, this disclosure relates to systems and methods for controlling power generation facilities (e.g., wind farms) connected to a power grid. In particular, this disclosure may include systems and methods that can facilitate the adjustment of power generation output of various power generation assets (e.g., wind turbines in a wind farm) to meet demand signals from the power grid. Therefore, a facility-level controller can determine a reactive power transfer factor for each power generation asset. The reactive power transfer factor may include a reactive power generation factor and / or a reactive power transmission factor.

[0038] The reactive power transfer factor indicates the incremental cost for each generating asset to send an additional unit of reactive power to the point of interest (POI) of the generating facility. This incremental cost can be attributed to static impedance due to site layout and cable size, and to dynamic transmission efficiency related to the location of each generating asset on the feeder.

[0039] The reactive power generation factor indicates the impact on the active power generation capacity of each of the generating assets when additional reactive power generation is requested from each of the generating assets. The reactive power generation factor can be based on the operating status of each generating asset. Operating status can include the active power generation level, reactive power generation level, voltage setpoint, and operating temperature of each generating asset.

[0040] Based on the reactive power transfer factor, the controller of a power generation facility can rank various power generation assets and allocate demand signals based on this ranking. In other words, the controller can assign a larger portion of the demand signals to those power generation assets best suited to meet the demand, as indicated by the reactive power transfer factor, while minimizing the impact on the amount of active power generated that is transferred to the Point of Interest (POI) and ultimately sold to the grid.

[0041] Now refer to the diagram, Figure 1 A perspective view illustrating one embodiment of the power generation asset 100 according to this disclosure is shown. Figure 1 As depicted, in one embodiment, power generation asset 100 may be a wind turbine. However, in additional embodiments, power generation asset 100 may be any other suitable power generation asset, such as a hydroelectric turbine, a solar system, a fossil fuel generator, and / or a combination thereof. In yet another embodiment, power generation asset 100 may be a sub-station of multiple individual power generation assets 100.

[0042] like Figure 1 As depicted, when configured as a wind turbine, the power generation asset 100 typically includes a tower 102 extending from a support surface 104, a nacelle 106 mounted on the tower 102, and a rotor 108 coupled to the nacelle 106. The rotor 108 includes a rotatable hub 110 and at least one rotor blade 112 coupled to and extending outward from the hub 110. For example, in the illustrated embodiment, the rotor 108 includes three rotor blades 112. However, in alternative embodiments, the rotor 108 may include more than three or fewer rotor blades 112. Each rotor blade 112 may be spaced apart around the hub 110 to facilitate rotation of the rotor 108, thereby enabling kinetic energy from the wind to be converted into usable mechanical energy and subsequently into electrical energy. For example, the hub 110 may be rotatably coupled to a generator (not shown) positioned within the nacelle 106 to allow electrical energy to be generated.

[0043] The power generation asset 100 may also include a controller 200. When configured as a wind turbine, the controller 200 may be centralized within the nacelle 106. However, in other embodiments, the controller 200 may be located within any other component of the power generation asset 100 or at a location outside the power generation asset 100. Furthermore, the controller 200 may be communicatively coupled to any number of components of the power generation asset 100 to control those components. In this way, the controller 200 may include a computer or other suitable processing unit. Therefore, in several embodiments, the controller 200 may include suitable computer-readable instructions that, when executed, configure the controller 200 to perform various functions, such as receiving, transmitting, and / or executing power generation asset control signals.

[0044] Still referencing Figure 1One or more sensors 156, 158 can be installed on the power generation asset 100 to monitor the performance of the power generation asset 100 and / or environmental conditions affecting the power generation asset 100. It should also be appreciated that, as used herein, the term "monitoring" and its variations indicate that various sensors on the power generation asset 100 can be configured to provide direct or indirect measurements of the parameter being monitored. Therefore, the sensors described herein can, for example, be used to generate signals relating to the parameter being monitored, which can then be used by the controller 200 to determine the condition of the power generation asset 100.

[0045] For example, as shown, each power generation asset in power generation asset 100 may include an environmental sensor 158 configured to collect data representing at least one environmental condition. The environmental sensor 158 may be operable to controller 200. Therefore, in embodiments, one or more environmental sensors 158 may be, for example, wind vanes, anemometers, lidar sensors, thermometers, barometers, or other suitable sensors. Data collected by the environmental sensors 158 may include measurements of wind speed, wind direction, wind shear, gusts, wind direction, atmospheric pressure, and / or temperature. In at least one embodiment, the environmental sensors 158 may be mounted to nacelle 106 at a leeward location of rotor 108. In alternative embodiments, the environmental sensors 158 may be coupled to rotor 108 or integrated with rotor 108. It should be appreciated that the environmental sensors 158 may include a network of sensors and may be positioned remotely from power generation asset 100. It should be further appreciated that, in embodiments, the environmental sensors 158 may provide data representing energy levels of the energy source to power generation asset 100.

[0046] In addition to one or more environmental sensors 158, the power generation asset 100 may also include one or more asset condition sensors 156. The asset condition sensors 156 may be configured, for example, to monitor the electrical characteristics of the output of the generator of each power generation asset in the power generation asset 100, such as current sensors, voltage sensors, temperature sensors, or power sensors that monitor power output directly based on current and voltage measurements. In at least one embodiment, the asset condition sensors 156 may include any other sensors that can be used to monitor the operating status of the power generation asset 100.

[0047] Now for reference Figure 2 This illustrates a schematic diagram of a power generation facility 152 controlled according to the system and method of this disclosure. In embodiments, such as... Figure 2As depicted, power generation facility 152 can be configured as a wind farm. However, in additional embodiments, power generation facility 152 can be any other suitable power generation facility, such as a hydroelectric power plant, a solar power plant, a fossil fuel generator site, and / or a combination thereof, such as hybrid power generation facility 160. Figure 4 As shown in the figure, power generation facility 152 may include multiple power generation assets 100 as described herein, as well as a controller 200. The controller 200 may be configured as a facility-level controller 202. For example, as shown in the illustrated embodiment, power generation facility 152 may include twelve power generation assets 100. However, in other embodiments, power generation facility 152 may include any other number of power generation assets 100, such as fewer than twelve or more than twelve power generation assets 100. In one embodiment, the controllers 200(of one or more) of the power generation assets 100 may be communicatively coupled to the facility-level controller 202 via a wired connection, such as by means of connecting the controllers 200(of one or more) via a suitable communication link 154 (e.g., a suitable cable). Alternatively, the controllers 200(of one or more) may be communicatively coupled to the facility-level controller 202 via a wireless connection, such as by means of any suitable wireless communication protocol known in the art. Additionally, the facility-level controller 202 may generally be configured similarly to the controller 200 of each of the individual power generation assets 100 within power generation facility 152.

[0048] In an embodiment, the facility-level controller 202 may also be operatively coupled to at least one grid sensor 162. One or more grid sensors 162 may be operatively coupled to the power grid. One or more grid sensors 162 may be configured to detect demand signals from the power grid. In at least one embodiment, the demand signal may be a reactive power demand signal 302. Figure 6 It should be recognized that, in the additional embodiments, the demand signal may also be a voltage setpoint, a reactive power setpoint, or other power factor setpoint.

[0049] Now for reference Figure 3In several embodiments, the power generation facility 152 may include at least one feeder 130. One or more feeders 130 may electrically couple the power generation asset 100 to an interconnection point (POI) 132 of the power generation facility 152 and ultimately to the power grid. In embodiments, power may be transferred between the power generation asset 100 and the POI 132 along one or more feeders 130. For example, in at least one embodiment, power generated by the power generation asset 100 may be transferred along one or more feeders 130 to the POI 132 and ultimately to the power grid. In additional embodiments, active and / or reactive power may be transferred to the power generation asset 100 via one or more feeders 130.

[0050] In at least one embodiment, a portion of the power generation assets 100 may be distributed in series as an asset group 134 along a single feeder 130. In such an embodiment, voltage steps or voltage bowls may occur in said portion of the power generation assets 100 distributed along feeder 130. A voltage step may occur when the power generation asset 100 closest to the POI 132 generates a certain percentage more power than required to drive the generated power to POI 132. This can result in the line voltage at subsequent power generation assets 100 in series being the required power generation plus the excess percentage generated by the preceding power generation asset 100. As a result, subsequent power generation assets 100 may generate an additional percentage of power to overcome the increase in line voltage. For example, in an embodiment where three power generation assets 100 may be arranged in series, the first power generation asset 100(a) may generate 105% of the required voltage, the second power generation asset 100(b) may generate 107% of the required voltage, while the third power generation asset 100(c) located furthest from POI 132 may be required to generate 112% of the required power generation. In this case, the third power generation asset 100 could be required to operate at a non-nominal voltage. It should be recognized that the increased power generation level of the subsequent power generation asset 100 may be associated with a decrease in the asset's ability to meet reactive power generation requirements.

[0051] like Figure 4 As depicted, in one embodiment, power generation facility 152 may be configured as a hybrid power generation facility 160. For example, power generation facility 152 may include a wind turbine 136, solar panels 138, a hydroelectric power generation facility 140, and / or a fossil fuel generator 142. In one embodiment, the wind turbine 136, solar panels 138, hydroelectric power generation facility 140, and / or fossil fuel generator 142 may be coupled to multiple substations 144 of power generation facility 152. In at least one embodiment, the multiple substations 144 may be considered as power generation asset 100.

[0052] Now for reference Figure 5-7Schematic diagrams of several embodiments of a system 300 for controlling a power generation facility 152 according to the present disclosure are presented. In particular, as Figure 4 The diagram illustrates an embodiment of suitable components that can be included within controller 200. For example, as shown, controller 200 may include one or more processors 206 and / or associated memory devices 208, configured to perform various computer-implemented functions (e.g., performing methods, steps, calculations, etc., and storing related data, as disclosed herein). Additionally, controller 200 may include a communication module 210 to facilitate communication between controller 200 and various components of power generation asset 100. Furthermore, communication module 210 may include a sensor interface 212 (e.g., one or more analog-to-digital converters) to allow signals transmitted from one or more sensors 156, 158, 162 to be converted into signals that can be understood and processed by processor 206. It should be appreciated that any suitable means can be used to communicatively couple sensors 156, 158, 162 to communication module 210. For example, as... Figure 5 As shown, sensors 156, 158, and 162 are coupled to sensor interface 212 via a wired connection. However, in other embodiments, sensors 156, 158, and 162 may be coupled to sensor interface 212 via a wireless connection, such as by using any suitable wireless communication protocol known in the art. Additionally, communication module 210 may also be operatively coupled to operating state control module 214, which is configured to change the operating state of at least one power generation asset.

[0053] As used herein, the term "processor" refers not only to an integrated circuit known in the art as included in a computer, but also to a controller, microcontroller, microcomputer, programmable logic controller (PLC), application-specific integrated circuit, and other programmable circuits. Additionally, memory device(s) 208 typically includes memory elements(s), including but not limited to computer-readable media (e.g., random access memory (RAM)), computer-readable non-volatile media (e.g., flash memory), floppy disks, optical disc read-only memory (CD-ROM), magneto-optical disc (MOD), digital versatile optical disc (DVD), and / or other suitable memory elements. One or more such memory devices 208 may typically be configured to store suitable computer-readable instructions that, when executed by one or more processors 206, configure controller 200 to perform various functions as described herein, including but not limited to determining the reactive power transfer factor of each of the power generation assets, determining a portion of a demand signal to be satisfied by each of the power generation assets based on the reactive power transfer factor of each of the power generation assets, generating a reactive power setpoint command for each of the power generation assets and transmitting the reactive power setpoint command to each of the power generation assets to control the reactive power output of each of the power generation assets, and various other suitable computer-implemented functions.

[0054] Special Reference Figure 6 In one embodiment, the facility-level controller 202 of system 300 may be configured to receive a demand signal from the power grid, which may be a reactive power demand signal 302. In some embodiments, the reactive power demand signal 302 may indicate the amount of increased reactive power to be supplied to the power grid by the generation facility 152. In an additional embodiment, the demand signal 302 may indicate the amount of decreased reactive power to be supplied to the power grid by the generation facility 152.

[0055] In an embodiment, such as Figure 6 As shown, the facility-level controller 202 can also be configured to determine a reactive power transfer factor 304 for each of the power generation assets 100. The reactive power transfer factor 304 may include at least one of a reactive power generation factor 306 and a reactive power transfer factor 308. The reactive power transfer factor 304 may represent the impact on the active power generation capacity of each of the power generation assets 100 due to an increase in the amount of reactive power transferred to the POI 132 of the power generation facility 152.

[0056] Still referencing Figure 6In one embodiment, the facility-level controller 202 may be configured to determine a portion 310 of a reactive power demand signal 302 to be satisfied by each of a plurality of power generation assets 100. This determination may be based on a reactive power transfer factor 304 for each of the power generation assets 100. In one embodiment, the portion 310 of the reactive power demand signal 302 to be satisfied by at least one power generation asset 100 may be greater than the portion 310 to be satisfied by at least one other power generation asset 100.

[0057] like Figure 6 Further described, in at least one embodiment, the facility-level controller 202 can be configured to generate setpoint commands 312 for each of the power generation assets 100. In at least one embodiment, the setpoint command 312 can be a reactive power setpoint command 312. At 314, the reactive power setpoint command 312 can be transmitted to each of the plurality of power generation assets 100 to control the reactive power output of each of the plurality of power generation assets 100.

[0058] In an embodiment, the facility-level controller 202 of system 300 may be configured to determine a reactive power transfer factor 308 for each of the generating assets 100. The reactive power transfer factor 308 may represent the ability of each of the generating assets 100 to transfer reactive power to POI 132. In at least one embodiment, the reactive power transfer factor 308 may be based at least in part on the distance between each of the generating assets 100 and POI 132. For example, as discussed earlier, in embodiments where a portion of the generating assets 100 may be arranged as asset group 134 along feeder 130, voltage tiering effects may reduce the ability of some of the generating assets 100 to provide an increased level of reactive power to POI 132.

[0059] In at least one embodiment, the effect of voltage bowl or voltage step effect can be determined as dynamic transfer efficiency 316 by facility-level controller 202. Dynamic transfer efficiency 316 can correspond to the ability of each power generation asset 100 in the power generation asset group 134 to transfer reactive power to POI 132 at a given power setpoint. In such an embodiment, facility-level controller 202 can receive data from one or more asset condition sensors 156 representing the operating state 318 of each power generation asset 100 along the asset group 134 of feeder 130. For example, the asset condition sensors 156 can provide real-time measurements of active power generation, reactive power generation, voltage setpoint, and operating temperature corresponding to each power generation asset 100. Thus, in at least one embodiment, facility-level controller 202 can determine the dynamic transfer efficiency 316 of each power generation asset 100 in the power generation asset group 134 based on the operating state 318 of each power generation asset 100 within each asset group 134 and the position of each power generation asset 100 within each asset group 134 relative to POI 132. It should be recognized that the ability of a single power generation asset 100 to transfer reactive power to POI 132 for a given setpoint can vary based on the behavior of each of the other power generation assets 100 on the same feeder 130.

[0060] In an additional embodiment, the reactive power transfer factor 308 may further include the point of interest (POI) impedance 320 of the power generation facility 152. The POI impedance 320 may be the impedance between the power generation asset 100 and the POI 132. In this embodiment, the POI impedance 320 can be derived from knowledge of the layout and cable dimensions of the power generation facility 152. In another embodiment, the POI impedance 320 of each power generation asset 100 location can be determined by an algorithm that individually tests each power generation asset 100 to derive the POI impedance 320 of each power generation asset 100. For example, the POI impedance 320 of each power generation asset 100 can be determined during commissioning of the power generation facility 152. In yet another embodiment, the facility-level controller 202 may analyze operational data to determine the POI impedance 320 of each power generation asset 100 during operational use.

[0061] In another embodiment, the facility-level controller 202 of system 300 can be configured to determine a reactive power transfer factor 308 by combining the POI impedance 320 and the dynamic transfer factor 316 of each of the generating assets 100 at 322. It should be appreciated that, in such an embodiment, the reactive power transfer factor 308 can reflect the incremental cost of each generating asset 100 sending an additional unit of reactive power to POI 132. In at least one embodiment, this incremental cost can be measured in kilowatts per kilovolt-ampere reactive power (kW / kVAR). In other words, the reactive power transfer factor 308 can reflect the reduction in the amount of active power that can be transferred to POI 132 by each of the generating assets 100 and ultimately sold to the grid.

[0062] In an embodiment, the controller 200 of system 300 may be configured to determine the operating state 318 of each of the power generation assets 100. The operating state may include the active power generation level, reactive power generation level, voltage setpoint, and / or operating temperature of each of the power generation assets 100. The controller 200 may also be configured to determine the reactive power generation factor 306 of each of the power generation assets 100. The reactive power generation factor 306 may represent, in kilowatts, the reduction in active power generation capacity of each power generation asset 100 for each unit increase in reactive power generation under the determined operating state 318. In other words, the reactive power generation factor 306 may represent the impact on the ability of each power generation asset 100 to generate active power that is ultimately sold to the grid when instructed to increase reactive power generation.

[0063] Still referencing Figure 6 306 and also refer to Figure 7 and Figure 8 In an embodiment, the controller 200 can determine at 324 whether the operating state 318 of the power generation asset 100 is configured to maximize power generation 326. For example, in Figure 8 In this context, various operating states 318 can be graphically depicted through the illustration of power curves related to the source energy level of power generation asset 100. For example... Figure 8 As depicted, the power level 328 can increase linearly with the increase of the source energy level until it reaches a threshold 330. In an embodiment, as the source energy level crosses the threshold 330, the power generation asset 100 can transition from an operating state configured to limit active power generation 332 to an operating state configured to maximize power generation 326, or vice versa.

[0064] In at least one embodiment, the operating state configured to limit active power generation 332 can be considered as the rated power of the power generation asset 100. It should be appreciated that the limit on active power generation can be implemented for various reasons related to component limitations, lifecycle limitations, and / or grid requirements. However, in embodiments, the rated power may not be the maximum power that the power generation asset 100 can generate based on the source energy level. Thus, in embodiments, an increased power generation 334 above the rated power may be available until an asset threshold 336 of the power generation asset 100 is reached. In at least one embodiment, the increased power generation 334 may take the form of an increase in reactive power generation.

[0065] In an embodiment where operating state 318 is configured to maximize power generation, controller 200 can be configured at 338 to model incremental costs in kilowatts, the incremental costs corresponding to a reduction in active power generation capacity required for an increase in the amount of reactive power generated under operating state 318. For example, in an embodiment where generator asset 100 is maximizing power generation at setpoint 340(A), an increase in power generation at a given source level may not meet the demand signal for the increased reactive power generation at setpoint 340(B). In such an embodiment, any increase in reactive power generation may require a reduction in active power generation. A reduction in active power generation may result in a reduction in the amount of active power that can be passed to POI 132 for eventual sale to the grid. In such an embodiment, reactive power generation factor 306 may be equal to the incremental cost in kilowatts for each additional unit of reactive power generated by generator asset 100.

[0066] In an additional embodiment, operating state 318 may be an operating state configured to limit power generation 332 (e.g., at rated power). In such an embodiment, the controller 200 of system 300 may be configured to determine a source energy level 342 sufficient to support an increased power generation 334 of at least one of the power generation assets 100. In such an embodiment, the controller 200 may determine at 344 whether the increased power generation 334 due to the increased reactive power generation is below an asset threshold 336. In embodiments where the increased power generation 334 is below the asset threshold 336, the increased power generation 334 may indicate an increase in reactive power generation while active power generation remains constant, resulting in a zero reactive power generation factor 306.

[0067] For example, in one embodiment, power generation asset 100 may be limiting power generation at setpoint 346(A). In such an embodiment, the reactive power demand signal 302 for the increased reactive power generation at setpoint 346(B) can be met by maintaining the active power generation level at 348 (e.g., setpoint 346(A)) and increasing the reactive power generation of power generation asset 100 at 350. In other words, the demand for the increased reactive power generation can be met by utilizing an increased power generation 334 that may be available above the rated power at the source energy level.

[0068] In another embodiment, when operating state 318 is configured to limit power generation 332, controller 200 can determine that the increased power generation required to satisfy reactive power demand signal 302 may exceed asset threshold 336. In such an embodiment, controller 200 can determine at 354 any first portion 356 of any increase in reactive power generation to be satisfied by the increased power generation 334 without exceeding asset threshold 336. In this embodiment, the first portion 356 can be subtracted from reactive power demand signal 302 at 360 to produce a second portion 358 of the increase in reactive power generation to be satisfied by a reduction in active power generation capacity. Controller 200 can model the incremental cost in kilowatts at 362, the incremental cost corresponding to the reduction in active power generation capacity required by the second portion 358 of the increased reactive power generation. The reactive power generation factor 306 can then be equal to the incremental cost in kilowatts for each additional unit of reactive power not satisfied by the increased power generation 334.

[0069] For example, in one embodiment, power generation asset 100 may be limiting power generation at setpoint 364(A). In such an embodiment, satisfying reactive power demand signal 302 may require an increased reactive power generation at setpoint 364(B). However, since setpoint 364(B) may exceed asset threshold 336, only the first portion 356 of the increase can be satisfied by the increased power generation 334. The remaining portion of the increase (e.g., the second portion 358) can then be satisfied by derated the power generation asset 100 to reduce active power generation. In at least one embodiment, derated power generation asset 100 may result in the establishment of a reduced active power generation setpoint 364(C).

[0070] Refer again Figure 6In one embodiment, the facility-level controller 202 can calculate the reactive power transfer factor 304 by combining the reactive power generation factor 306 and the reactive power transfer factor 308 at 366. In such an embodiment, the combination of the reactive power generation factor 306 and the reactive power transfer factor 308 can indicate the impact on the active power generation capacity of each of the power generation assets 100 due to the increase in the amount of reactive power transferred to the POI 132 of the power generation facility 152. In other words, in one embodiment, the reactive power transfer factor 304 can reflect the reduction in active power generation due to the incremental cost of each power generation asset 100 sending additional reactive power to the POI 132 and the loss of generation capacity required by the reactive power demand signal 302.

[0071] Still referencing Figure 6 In this embodiment, the facility-level controller 202 can rank the reactive power transfer factor 304 of each of the power generation assets 100 at 368. Therefore, a higher reactive power transfer factor 304 can indicate a greater impact on the active power generation capacity of one of the power generation assets 100 compared to a lower reactive power transfer factor 304 of another power generation asset 100. Conversely, a power generation asset 100 with a lower reactive power transfer factor 304 may be more capable of providing an increased amount of reactive power generation while minimizing the impact on active power generation. Thus, it is desirable to prioritize the reactive power generation of those power generation assets 100 with relatively lower reactive power transfer factors 304. Based on the ranking, the facility-level controller 202 can determine at 310 the distribution of portions of the reactive power demand signal 302 to be satisfied by each of the power generation assets 100 of the power generation facility 152. It should be recognized that a portion of the reactive power demand signal 302 satisfied by each of the generating assets can be adjusted to reflect the asset's ability to transfer reactive power to POI 132, as indicated by the reactive power transfer factor 304. It should be further recognized that a portion of the reactive power demand signal 302 satisfied by at least one of the generating assets 100 may differ from a portion of the reactive power demand signal 302 satisfied by at least one other generating asset 100.

[0072] Furthermore, those skilled in the art will recognize the interchangeability of various features from different embodiments. Similarly, those skilled in the art can mix and match the various method steps and features described, as well as other known equivalents of each such method and feature, to construct additional systems and techniques in accordance with the principles of this disclosure. Of course, it is to be understood that not all such objects or advantages described above may be achieved according to any particular embodiment. Therefore, for example, those skilled in the art will recognize that the systems and techniques described herein can be embodied or performed in a manner that achieves or optimizes one or a set of advantages as taught herein, without necessarily achieving other objects or advantages as may be taught or suggested herein.

[0073] This written description uses examples to disclose the invention, including the best mode, and also enables any person skilled in the art to implement the invention, including making and using any device or system and performing any combined methods. The patentable scope of the invention is defined by the claims, and the patentable scope of the invention may include other examples that would occur to a person skilled in the art. Such other examples are determined to be within the scope of the claims if they include structural elements that are not different from the literal language of the claims, or if such other examples include equivalent structural elements that are not substantially different from the literal language of the claims.

[0074] Further aspects of the invention are provided through the subject matter of the following clauses:

[0075] Clause 1: A method for controlling a power generation facility connected to a power grid, the power generation facility having multiple power generation assets, the method comprising: receiving a reactive power demand signal from the power grid using a facility-level controller of the power generation facility; determining a reactive power transfer coefficient for each of the power generation assets using the facility-level controller, the reactive power transfer coefficient including at least one of a reactive power generation coefficient and a reactive power transmission coefficient, wherein the reactive power transfer coefficient represents the impact on the active power generation capacity of each of the power generation assets due to an increase in the amount of reactive power transmitted to the interconnection point (POI) of the power generation facility; determining, using the facility-level controller, a portion of the reactive power demand signal to be satisfied by each of the multiple power generation assets based on the reactive power transfer coefficient of each of the power generation assets, wherein the portion of the reactive power demand signal satisfied by at least one power generation asset is larger than the portion satisfied by at least one other power generation asset; generating a reactive power setpoint command for each of the power generation assets using the facility-level controller; and transmitting the reactive power setpoint command to each of the multiple power generation assets to control the reactive power output of each of the multiple power generation assets.

[0076] Clause 2: The method described in any of the preceding clauses, wherein determining which portion of the reactive power demand signal is to be satisfied by each of the plurality of generating assets further comprises: ranking the reactive power transfer coefficients of each of the generating assets using a facility-level controller, wherein a higher reactive power transfer coefficient indicates a greater impact on the active power generation capacity of one of the generating assets compared to a lower reactive power transfer coefficient of another of the plurality of generating assets, and wherein the distribution of portions of the reactive power demand signal is based on the ranking.

[0077] Clause 3: The method described in any of the preceding clauses, wherein determining the reactive power transfer factor further comprises: using a facility-level controller to determine the reactive power transfer factor for each of the generating assets, wherein the reactive power transfer factor represents the ability of each of the generating assets to transfer reactive power to the POI, the reactive power transfer factor being based at least in part on the distance between each of the generating assets and the POI.

[0078] Clause 4: The method described in any of the preceding clauses, wherein determining the reactive power transfer factor further comprises: using a facility-level controller to combine the POI impedance of the generating facility with the dynamic transfer efficiency of each generating asset in the generating assets, wherein the transfer efficiency corresponds to the ability of each generating asset in the generating assets to transfer reactive power to the POI at a given power setpoint.

[0079] Clause 5: The method as described in any of the preceding clauses, wherein multiple power generation assets are divided into multiple asset groups, each asset group being coupled to a corresponding feeder for being serially coupled to a POI, the method further comprising: receiving an indication of the operating status of each power generation asset using a facility-level controller, the operating status including the active power generation, reactive power generation, voltage setpoint, and operating temperature of each power generation asset; and determining the dynamic transmission efficiency of each power generation asset based on the operating status of each power generation asset within each asset group and the position of each power generation asset within each asset group relative to the POI using the facility-level controller.

[0080] Clause 6: The method described in any of the preceding clauses, wherein determining the reactive power transfer factor further comprises: using a controller to determine the operating state of each of the power generation assets, the operating state including the active power generation, reactive power generation, voltage setpoint, and operating temperature of each of the power generation assets; and using a controller to determine the reactive power generation factor of each of the power generation assets, wherein the reactive power generation factor represents the reduction in active power generation capacity in kilowatts for each unit increase in reactive power generation of each power generation asset under the determined operating state.

[0081] Clause 7: The method described in any of the preceding clauses, wherein determining the reactive power transfer factor further comprises: using a facility-level controller to determine the reactive power transfer factor for each of the generating assets, wherein the reactive power transfer factor represents the ability of each of the generating assets to transfer reactive power to the POI, the reactive power transfer factor being at least partially based on the distance between each of the generating assets and the POI; and calculating the reactive power transfer factor by using a facility-level controller in combination with the reactive power generation factor and the reactive power transfer factor.

[0082] Clause 8: The method as described in any of the preceding clauses, wherein the operating state is configured to maximize power generation, and wherein determining the reactive power generation factor further comprises: modeling an incremental cost in kilowatts using a controller, the incremental cost corresponding to a reduction in active power generation capacity required for an increase in the amount of reactive power generated in the operating state, wherein the reactive power generation factor is equal to the incremental cost in kilowatts for each additional unit of reactive power.

[0083] Clause 9: The method as described in any of the preceding clauses, wherein the operating state is an operating state configured to limit the amount of power generation, and wherein determining the reactive power generation factor further comprises: using a controller to determine a source energy level sufficient to support an increase in the amount of power generation of at least one of the power generation assets, wherein the increase in the amount of power generation is below an asset threshold, and wherein the increase in the amount of power generation includes an increase in the amount of reactive power generation while the amount of active power generation remains constant, wherein the amount of active power generation produces a reactive power generation factor of zero.

[0084] Clause 10: The method as described in any of the preceding clauses, wherein the operating state is configured to limit power generation, and wherein determining the reactive power generation factor further comprises: using a controller to determine a source energy level sufficient to support an increase in power generation for at least one of the power generation assets; using a controller to determine a first portion of the increase in reactive power generation satisfied by the increased power generation without exceeding an asset threshold; and using a controller to model an incremental cost in kilowatts, the incremental cost corresponding to a reduction in active power generation capacity required by a second portion of the increase in reactive power generation, wherein the reactive power generation factor is equal to the incremental cost in kilowatts for each additional unit of reactive power not satisfied by the increased power generation.

[0085] Clause 11: As described in any of the foregoing clauses, the power generation facility includes a wind farm and the multiple power generation assets include multiple wind turbines.

[0086] Clause 12: As described in any of the foregoing clauses, the plurality of power generation assets includes a plurality of substations of power generation facilities.

[0087] Clause 13: A system for controlling a power generation facility, the system comprising: a plurality of power generation assets coupled to a power grid; and a facility-level controller communicatively coupled to the plurality of power generation assets and to the power grid, the facility-level controller including at least one processor configured to perform a plurality of operations, the plurality of operations including: receiving a reactive power demand signal from the power grid; determining a reactive power transfer coefficient for each of the power generation assets, the reactive power transfer coefficient including at least one of a reactive power generation coefficient and a reactive power transmission coefficient, wherein the reactive power transfer coefficient represents an increase in the amount of reactive power transferred to the interconnection point (POI) of the power generation facility. The impact on the active power generation capacity of each of the power generation assets is determined based on the reactive power transfer coefficient of each of the power generation assets, wherein a portion of the reactive power demand signal to be satisfied by each of the plurality of power generation assets is determined, wherein the portion of the reactive power demand signal to be satisfied by at least one power generation asset is larger than the portion to be satisfied by at least one other power generation asset, a reactive power setpoint command is generated for each of the power generation assets, and the reactive power setpoint command is transmitted to each of the plurality of power generation assets to control the reactive power output of each of the plurality of power generation assets.

[0088] Clause 14: A system as described in any of the preceding clauses, wherein determining which portion of the reactive power demand signal is to be satisfied by each of the plurality of generating assets further comprises: ranking the reactive power transfer coefficients of each of the generating assets, wherein a higher reactive power transfer coefficient indicates a greater impact on the active power generation capacity of one of the generating assets, compared to a lower reactive power transfer coefficient of another of the plurality of generating assets, and wherein the distribution of portions of the reactive power demand signal is based on the ranking.

[0089] Clause 15: A system as described in any of the preceding clauses, wherein determining the reactive power transfer factor further comprises: combining the POI impedance of the generating facility with the dynamic transfer efficiency of each generating asset, wherein the transfer efficiency corresponds to the ability of each generating asset to transfer reactive power to the POI at a given power setpoint; and determining a reactive power transfer factor for each generating asset, wherein the reactive power transfer factor represents the ability of each generating asset to transfer reactive power to the POI, the reactive power transfer factor being at least partially based on the distance between each generating asset and the POI.

[0090] Clause 16: A system as described in any of the preceding clauses, wherein multiple power generation assets are divided into multiple asset groups, each asset group being coupled to a corresponding feeder for being serially coupled to a POI, the method further comprising: receiving an indication of the operating status of each power generation asset, the operating status including the active power generation, reactive power generation, voltage setpoint, and operating temperature of each power generation asset; and determining the dynamic transmission efficiency of each power generation asset based on the operating status of each power generation asset within each asset group and the position of each power generation asset within each asset group relative to the POI.

[0091] Clause 17: A system as described in any of the preceding clauses, wherein determining the reactive power transfer factor further comprises: using a controller to determine the operating state of each of the power generation assets, the operating state including the active power generation, reactive power generation, voltage setpoint, and operating temperature of each of the power generation assets; and using a controller to determine the reactive power generation factor of each of the power generation assets, wherein the reactive power generation factor represents, in kilowatts, the reduction in active power generation capacity of each power generation asset for each unit increase in reactive power generation under the determined operating state.

[0092] Clause 18: A system as described in any of the preceding clauses, wherein determining the reactive power transfer factor further comprises: calculating the reactive power transfer factor by combining the reactive power generation factor and the reactive power transmission factor.

[0093] Clause 19: A system as described in any of the preceding clauses, wherein the operating state is configured to limit power generation, and wherein determining the reactive power generation factor further comprises: using a controller to determine a source energy level sufficient to support an increase in power generation for at least one of the power generation assets; using a controller to determine a first portion of the increase in reactive power generation satisfied by the increased power generation without exceeding an asset threshold; and using a controller to model an incremental cost in kilowatts corresponding to a reduction in active power generation capacity required by a second portion of the increase in reactive power generation, wherein the reactive power generation factor is equal to the incremental cost in kilowatts for each additional unit of reactive power not satisfied by the increased power generation.

[0094] Clause 20: A system as described in any of the preceding clauses, wherein the power generation facilities include wind farms and multiple power generation assets include multiple wind turbines.

Claims

1. A method for controlling a power generation facility connected to a power grid, the power generation facility having multiple power generation assets, the method comprising: The reactive power demand signal from the power grid is received using the facility-level controller of the power generation facility; The reactive power transfer coefficient of each power generation asset in the power generation assets is determined using the facility-level controller. The reactive power transfer coefficient includes a reactive power generation coefficient and a reactive power transmission coefficient, wherein the reactive power transfer coefficient represents the impact of changes in the amount of reactive power transferred to the interconnection point (POI) of the power generation facility on the active power generation capacity of each power generation asset in the power generation assets. The facility-level controller uses the reactive power transfer coefficient of each of the power generation assets to determine a portion of the reactive power demand signal to be satisfied by each of the plurality of power generation assets, wherein the portion of the reactive power demand signal to be satisfied by at least one power generation asset is larger than the portion to be satisfied by at least one other power generation asset. The facility-level controller generates reactive power setpoint commands for each of the power generation assets; and The reactive power setpoint command is transmitted to each of the plurality of power generation assets in order to control the reactive power output of each of the plurality of power generation assets. Determining the reactive power transfer coefficient further includes: The controller determines the operating status of each power generation asset, including its active power generation, reactive power generation, voltage setpoint, and operating temperature. The controller is used to determine the reactive power generation coefficient for each of the power generation assets, wherein the reactive power generation coefficient represents the reduction in active power generation capacity in kilowatts for each unit increase in reactive power generation under a given operating condition.

2. The method as described in claim 1, wherein, Determining which portion of the reactive power demand signal should be satisfied by each of the plurality of power generation assets further includes: The reactive power transfer coefficient of each of the power generation assets is ranked using the facility-level controller, wherein a higher reactive power transfer coefficient indicates a greater impact on the active power generation capacity of one of the power generation assets compared to a lower reactive power transfer coefficient of another power generation asset among the plurality of power generation assets, and wherein the distribution of the portion of the reactive power demand signal is based on the ranking.

3. The method as described in claim 1, wherein, Determining the reactive power transfer coefficient further includes: The reactive power transfer factor for each of the power generation assets is determined using the facility-level controller, wherein the reactive power transfer factor represents the ability of each of the power generation assets to transfer reactive power to the POI, and the reactive power transfer factor is based at least in part on the distance between each of the power generation assets and the POI.

4. The method of claim 3, wherein, Determining the reactive power transmission coefficient further includes: The facility-level controller combines the POI impedance of the power generation facility with the dynamic transmission efficiency of each power generation asset, wherein the dynamic transmission efficiency corresponds to the ability of each power generation asset to transmit reactive power to the POI at a given power setpoint.

5. The method of claim 4, wherein, The plurality of power generation assets are divided into a plurality of asset groups, each asset group being coupled to a corresponding feeder for being serially coupled to the POI, the method further comprising: The facility-level controller receives indications of the operating status of each of the power generation assets, including the active power generation, reactive power generation, voltage setpoint, and operating temperature of each asset. The facility-level controller uses the operating status of each power generation asset within each asset group and the position of each power generation asset within each asset group relative to the POI to determine the dynamic transmission efficiency of each power generation asset.

6. The method of claim 1, wherein, Determining the reactive power transfer coefficient further includes: The reactive power transfer factor for each of the power generation assets is determined using the facility-level controller, wherein the reactive power transfer factor represents the ability of each of the power generation assets to transfer reactive power to the POI, and the reactive power transfer factor is based at least in part on the distance between each of the power generation assets and the POI; and The reactive power transfer coefficient is calculated by using the facility-level controller in conjunction with the reactive power generation coefficient and the reactive power transfer coefficient.

7. The method of claim 1, wherein, The operating state is configured to maximize power generation, and determining the reactive power generation coefficient further includes: The controller is used to model the incremental cost in kilowatts, which corresponds to the reduction in the active power generation capacity required for an increase in the amount of reactive power generated in the operating state, wherein the reactive power generation factor is equal to the incremental cost in kilowatts for each additional unit of reactive power.

8. The method of claim 1, wherein, The operating state is a state configured to limit the amount of power generated, and wherein determining the reactive power generation coefficient further includes: The controller is used to determine the source energy level sufficient to support an increased power generation amount for at least one of the power generation assets. Wherein, the increased power generation is below the asset threshold, and The increased power generation includes an increase in reactive power generation while the active power generation remains constant, wherein the reactive power generation coefficient is zero.

9. The method of claim 1, wherein, The operating state is a state configured to limit the amount of power generated, and wherein determining the reactive power generation coefficient further includes: The controller is used to determine the source energy level sufficient to support an increased power generation amount for at least one of the power generation assets; The controller determines a first portion of the increase in reactive power generation that is satisfied by the increased power generation without exceeding an asset threshold; and The controller is used to model the incremental cost in kilowatts, which corresponds to the reduction in the active power generation capacity required by the second portion of the increase in reactive power generation, wherein the reactive power generation factor is equal to the incremental cost in kilowatts for each additional unit of reactive power not satisfied by the increased power generation.

10. The method of claim 1, wherein, The power generation facilities include wind farms and the multiple power generation assets include multiple wind turbines.

11. The method of claim 1, wherein, The plurality of power generation assets include a plurality of substations of the power generation facilities.

12. A system for controlling a power generation facility, the system comprising: Multiple power generation assets coupled to the power grid; as well as A facility-level controller communicatively coupled to the plurality of power generation assets and communicatively coupled to the power grid, the facility-level controller including at least one processor configured to perform a plurality of operations, the plurality of operations including: Receive reactive power demand signals from the power grid. Determine the reactive power transfer factor for each of the power generation assets, wherein the reactive power transfer factor includes a reactive power generation factor and a reactive power transmission factor, wherein the reactive power transfer factor represents the impact on the active power generation capacity of each of the power generation assets due to the increase in the amount of reactive power transferred to the interconnection point (POI) of the power generation facility. A portion of the reactive power demand signal to be satisfied by each of the plurality of power generation assets is determined based on the reactive power transfer coefficient of each of the power generation assets, wherein the portion of the reactive power demand signal satisfied by at least one power generation asset is larger than the portion satisfied by at least one other power generation asset. Generate a reactive power setpoint command for each of the power generation assets, and, The reactive power setpoint command is transmitted to each of the plurality of power generation assets in order to control the reactive power output of each of the plurality of power generation assets. Determining the reactive power transfer coefficient further includes: The controller determines the operating status of each power generation asset, including its active power generation, reactive power generation, voltage setpoint, and operating temperature. The controller is used to determine the reactive power generation coefficient for each of the power generation assets, wherein the reactive power generation coefficient represents the reduction in active power generation capacity in kilowatts for each unit increase in reactive power generation under a given operating condition.

13. The system of claim 12, wherein, Determining which portion of the reactive power demand signal should be satisfied by each of the plurality of power generation assets further includes: The reactive power transfer coefficient of each of the power generation assets is ranked, wherein a higher reactive power transfer coefficient indicates a greater impact on the active power generation capacity of one of the power generation assets compared to a lower reactive power transfer coefficient of another power generation asset among the plurality of power generation assets, and wherein the distribution of the portion of the reactive power demand signal is based on the ranking.

14. The system of claim 12, wherein, Determining the reactive power transfer coefficient further includes: The POI impedance of the power generation facility is combined with the dynamic transmission efficiency of each power generation asset, wherein the dynamic transmission efficiency corresponds to the ability of each power generation asset to transmit reactive power to the POI at a given power setpoint; and Determine the reactive power transfer factor for each of the power generation assets, wherein the reactive power transfer factor represents the ability of each of the power generation assets to transfer reactive power to the POI, and the reactive power transfer factor is based at least in part on the distance between each of the power generation assets and the POI.

15. The system of claim 14, wherein, The plurality of power generation assets are divided into a plurality of asset groups, each asset group being coupled to a corresponding feeder for being serially coupled to the POI, and the plurality of operations further include: Receives an indication of the operating status of each of the power generation assets, the operating status including the active power generation, reactive power generation, voltage setpoint, and operating temperature of each power generation asset; and The dynamic transmission efficiency of each power generation asset in the power generation assets is determined based on the operating status of each power generation asset in each asset group and the position of each power generation asset in each asset group relative to the POI.

16. The system of claim 12, wherein, Determining the reactive power transfer coefficient further includes: The reactive power transfer coefficient is calculated by combining the reactive power generation coefficient and the reactive power transfer coefficient.

17. The system of claim 12, wherein, The operating state is a state configured to limit the amount of power generated, and wherein determining the reactive power generation coefficient further includes: The controller is used to determine the source energy level sufficient to support an increased power generation amount for at least one of the power generation assets; The controller determines a first portion of the increase in reactive power generation that is satisfied by the increased power generation without exceeding an asset threshold; and The controller is used to model the incremental cost in kilowatts, which corresponds to the reduction in the active power generation capacity required by the second portion of the increase in reactive power generation, wherein the reactive power generation factor is equal to the incremental cost in kilowatts for each additional unit of reactive power not satisfied by the increased power generation.

18. The system of claim 12, wherein, The power generation facilities include wind farms and the multiple power generation assets include multiple wind turbines.

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