System and method for plant-level coordination of inertial power response of inverter-based resources for grid formation

Abstract

A method of coordinating inertial power responses of a plurality of inverter-based resources in a power plant connected to a power grid includes receiving, via a plant-level controller of the power plant, at least one of a desired plant inertia or a desired plant inertial power capability. The method also includes continuously determining, via the plant-level controller, at least one of an inertia power limit, a virtual inertia setting, or an active power reference change and sending it to each of the plurality of inverter-based resources. Further, the method includes coordinating an inertial power response of the power plant via the plant-level controller by allowing a respective controller of each of the plurality of inverter-based resources to independently respond to a grid frequency event without exceeding the inertial power limit, to satisfy at least one of the desired plant inertia or the desired plant inertia power capability.

Description

Technical Field

[0001] The present disclosure relates generally to inverter-based resources, such as wind turbine power systems, and more particularly to systems and methods for plant-level coordination of inertial power responses of inverter-based resources for grid formation. Background Art

[0002] Wind power is considered one of the cleanest, most environmentally friendly energy sources currently available, and wind turbines are gaining increasing attention in this regard. A modern wind turbine typically comprises a tower, a generator, a gearbox, a nacelle, and one or more rotor blades. The rotor blades capture the kinetic energy of the wind using the known airfoil principle. For example, the rotor blades typically have an airfoil-shaped cross-sectional profile so that during operation, air flows over the blades, creating a pressure difference between the two sides. Consequently, a lift force acts on the blades from the pressure side toward the suction side. This lift force generates torque on the main rotor shaft, which is typically meshed with a generator for generating electricity.

[0003] Wind turbines can be categorized into two types: fixed-speed and variable-speed turbines. Typically, variable-speed wind turbines are controlled as current sources connected to the power grid. In other words, variable-speed wind turbines rely on the grid frequency, detected by a phase-locked loop (PLL), as a reference and inject a specified amount of current into the grid. Conventional current source control of wind turbines is based on the assumption that the grid voltage waveform is a fundamental voltage waveform with a fixed frequency and amplitude, and that wind power penetration into the grid is sufficiently low to not interfere with the grid voltage amplitude and frequency. Therefore, the wind turbine injects only a specified current into the grid based on the fundamental voltage waveform. However, with the rapid growth of wind power, wind power penetration into some grids has increased to the point where wind turbine generators have a significant impact on the grid voltage and frequency. When wind turbines are located in weak grids, wind turbine power fluctuations can lead to increased variations in the amplitude and frequency of the grid voltage. These fluctuations can adversely affect the performance and stability of the PLL and wind turbine current control.

[0004] Many existing renewable generation converters (e.g., doubly-fed wind turbine generators) operate in a "grid-following" mode. Grid-following devices utilize a fast current regulation loop to control the active and reactive power exchanged with the grid. More specifically, Figure 1The main circuit and basic elements of the converter control structure of a doubly-fed wind turbine generator for grid following are shown. As shown, the active power reference for the converter is formed by the energy source regulator (e.g., the turbine control section of the wind turbine). This is communicated as a torque reference representing the smaller of the maximum available power from the energy source at that moment or a curtailment command from a higher-level grid controller. The converter control then determines a current reference for the active component of the current to achieve the desired torque. Therefore, the doubly-fed wind turbine generator includes functionality to manage voltage and reactive power in a manner that results in a command for the reactive component of the current. A wide-bandwidth current regulator then forms a command for the voltage applied to the system by the converter so that the actual current closely tracks the command.

[0005] Alternatively, a grid-forming converter provides a voltage source characteristic in which the angle and magnitude of the voltage are controlled to achieve the regulation function required by the grid. With this structure, current will flow according to the grid's needs, while the converter helps establish the voltage and frequency for the grid. This characteristic is comparable to a conventional generator based on a turbine driving a synchronous machine. Therefore, a grid-forming source must include the following basic functions: (1) support grid voltage and frequency for any current flow within the device's rating, both real and reactive; (2) prevent operation beyond the device's voltage or current capabilities by allowing the grid voltage or frequency to change without disconnecting the device (disconnection is only allowed when the voltage or frequency exceeds the limits established by the grid entity); (3) remain stable for any grid configuration or load characteristic including: serving isolated loads or connecting to other grid-forming sources, and switching between such configurations; (4) share the total load of the grid among other grid-forming sources connected to the grid; (5) ride across major and minor grid disturbances; and (6) meet requirements (1)-(5) without requiring rapid communication with other control systems present in the grid or externally generated logic signals associated with grid configuration changes.

[0006] In the early 1990s, basic control structures for achieving the above-mentioned grid-forming objectives were developed and field-proven for battery systems (e.g., see U.S. Patent No. 5,798,633, entitled “Battery Energy Storage Power Conditioning System”). Applications to full-converter wind and solar generators are disclosed in U.S. Patent No. 7,804,184, entitled “System and Method for Control of a Grid-Connected Power Generating System” and U.S. Patent No. 9,270,194, entitled “Controller for controlling a power converter.” Applications to grid-forming control for doubly-fed wind turbine generators are disclosed in PCT / US2020 / 013787, entitled “System and Method for Providing Grid-Forming Control for a Double-Feb Wind Turbine Generator.”

[0007] As an example, Figure 2 A schematic diagram of an embodiment of the main circuit of a grid forming system is shown. As shown, the main circuit comprises a power electronic converter with connections on the DC and AC sides. This converter receives gating commands from a controller, which generates an AC voltage phasor Vcnv at an angle Thvcnv. The DC side is supplied with devices capable of generating or absorbing power even for short durations. Such devices may include, for example, batteries, solar panels, rotating machines with rectifiers, or capacitors. In addition, as shown, the circuit comprises connecting the converter to the rectifier shown as Figure 2 The inductive impedance Xcnv of its interconnection point at a voltage Vt and an angle ThVt is shown. The electrical system behind the interconnection point is shown as a Thevenin equivalent with an impedance Zthev and a voltage Vthev at an angle ThVthev. This equivalent can be used to represent any circuit, including grid connections with loads and island circuits. In practical situations, the impedance Zthev will be primarily inductive.

[0008] Still refer to Figure 2 The closed loop portion of the main control receives feedback signals from the voltage and current at the interconnection point. Additional inputs are received from higher level controls (not shown). Figure 2 A single converter is shown as an example, but any grouping of devices that can produce the electrical equivalent of a controlled voltage Vcnv across an impedance Xcnv can apply the disclosed control scheme to achieve the same performance benefits.

[0009] Now refer to Figure 3 , illustrates a control diagram for providing grid forming control according to a conventional configuration. As shown, the converter controller 1 receives references (e.g., Vref and Pref) and limits (e.g., VcmdLimits and PcmdLimits) from a higher-level control 2. These higher-level limits are physical quantities of voltage, current, and power. The main regulator comprises a fast voltage regulator 3 and a slow power regulator 4. These regulators 3, 4 have control logic applied to them for voltage magnitude (e.g., VcnvCmd) and angle (e.g., θ Pang and θ PLL ) to achieve constraints on the reactive and real components of the current, respectively. Furthermore, such limits are based on predetermined fixed values ​​as default values, wherein if the current exceeds the limit, closed-loop control is performed to reduce the limit.

[0010] To be effective, the inverter-based resources (IBRs) of grid formation (GFM) must be able to maintain internal voltage phasors that do not shift rapidly when there are changes in grid conditions, such as the sudden addition / removal of loads, or the opening or closing of grid connections that result in phase jumps and / or rapid changes in frequency. In other words, the power from the grid formation resources must be able to change suddenly to stabilize the grid, followed by a slow reset to power commands from higher-level control functions. Furthermore, the grid formation resources must be able to quickly enforce power limits imposed by constraints on the power handling portion of the device (e.g., batteries, solar arrays, and / or DC voltage / current in wind power systems). This response is required for severe disturbances on the grid, such as faults where power limits are dynamically adjusted to coordinate with grid conditions for safe recovery from the fault. Furthermore, the grid formation resources should be able to quickly follow changes in commands from higher-level controls, such as for attenuating mechanical vibrations in wind turbines.

[0011] As IBRs continue to replace synchronous generators, they become even more important in providing some of the grid support services currently provided by synchronous generators, namely frequency and voltage support. However, a downside to the growing adoption of IBRs is the erosion of the high system inertia naturally provided by synchronous machines. GFM inverters have the ability to rapidly inject or absorb energy during frequency disturbances to simulate the natural inertial energy injection exhibited by synchronous machines.

[0012] Therefore, the present disclosure is directed to a control strategy in which a GFM IBR with inertial power response capability that mimics synchronous machines is allowed to quickly respond to grid frequency disturbances in an autonomous manner. Summary of the Invention

[0013] Aspects and advantages of the invention will be set forth in part in the following description, or may be obvious from the description, or may be learned through practice of the invention.

[0014] In one aspect, the present disclosure relates to a method for coordinating the inertial power response of a plurality of inverter-based resources in a power plant connected to a power grid. The method includes receiving, via a plant-level controller of the power plant, at least one of a desired plant inertia or a desired plant inertial power capability. The method also includes continuously determining, via the plant-level controller, at least one of an inertial power limit, a virtual inertial setting, or a real power reference change and sending it to each of the plurality of inverter-based resources. In addition, the method includes coordinating the inertial power response of the power plant, via the plant-level controller, to meet at least one of the desired plant inertia or the desired plant inertial power capability by allowing the respective controllers of each of the plurality of inverter-based resources to independently respond to grid frequency events without exceeding the inertial power limit.

[0015] In another aspect, the present disclosure relates to a system for coordinating the inertial power response of multiple grid-forming inverter-based resources in a power plant connected to a power grid. The system includes a plurality of local controllers and a plant-level controller communicatively coupled to the plurality of local controllers. The plant-level controller includes at least one processor configured to perform a plurality of operations, including but not limited to: receiving at least one of a desired plant inertia or a desired plant inertia power capability; continuously determining and sending at least one of an inertia power limit, a virtual inertia setting, or an active power reference change to each of the plurality of inverter-based resources; and coordinating the inertial power response of the power plant to meet at least one of the desired plant inertia or the desired plant inertia power capability by allowing the respective controllers of each of the plurality of inverter-based resources to independently respond to grid frequency events without exceeding the inertia power limit.

[0016] In yet another aspect, the present disclosure relates to a method for controlling a wind farm connected to a power grid, the wind farm having a plurality of wind turbines, wherein at least one of the plurality of wind turbines is a grid-forming wind turbine. The method includes receiving at least one of a desired instantaneous power or energy availability for the wind farm. The method also includes receiving at least one of transient power or energy availability feedback from each of the plurality of wind turbines. Furthermore, the method includes receiving steady-state power capabilities from each of the plurality of wind turbines. Furthermore, the method includes determining an expected portion of the desired transient power or energy availability of the wind farm to be met by each of the plurality of wind turbines based on the transient power or energy availability feedback from each of the plurality of wind turbines. Furthermore, the method includes determining at least one of a power limit for each of the plurality of wind turbines and a wind farm active power reduction setpoint based on the steady-state power capabilities from each of the plurality of wind turbines and the expected portion of the desired transient power or energy availability of the wind farm to be met by each of the plurality of wind turbines based on the transient power or energy availability feedback from each of the plurality of wind turbines. Additionally, the method includes controlling the wind farm based on the power limit to provide a desired transient power or energy to the power grid when a grid frequency or phase angle change occurs.

[0017] These and other features, aspects and advantages of the present invention will become better understood with reference to the following description and appended claims.The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the present invention and, together with the description, serve to explain the principles of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] A complete and enabling disclosure of the invention, including the best mode thereof, to one skilled in the art is set forth in the specification with reference to the accompanying drawings, in which:

[0019] Figure 1 illustrates a single line diagram of a doubly-fed wind turbine generator having a structure of converter control for grid following applications according to conventional construction;

[0020] Figure 2 A schematic diagram illustrating one embodiment of a main circuit of a grid forming system according to a conventional configuration;

[0021] Figure 3 illustrates a control diagram for providing grid forming control according to a conventional configuration;

[0022] Figure 4 illustrates a perspective view of one embodiment of a wind turbine according to the present disclosure;

[0023] Figure 5 illustrates a simplified interior view of one embodiment of a nacelle according to the present disclosure;

[0024] Figure 6 The diagram is suitable for Figure 1 A schematic diagram of one embodiment of a wind turbine electrical power system for use with the wind turbine shown in FIG;

[0025] Figure 7 A schematic diagram illustrating one embodiment of a wind farm having a plurality of wind turbines according to the present disclosure;

[0026] Figure 8 Picture provided Figure 1 A schematic diagram of another embodiment of a wind turbine electric power system for use with the wind turbine shown in ;

[0027] Figure 9 A block diagram illustrating one embodiment of a controller according to the present disclosure is shown;

[0028] Figure 10 A flow chart illustrating an embodiment of a method of coordinating the inertial power response of multiple grid-forming inverter-based resources in a power plant connected to a power grid according to the present disclosure;

[0029] Figure 11 and Figure 12 a control diagram illustrating an embodiment of a plant-level controller for coordinating the inertial power response of multiple grid-forming inverter-based resources in a power plant connected to a power grid in accordance with the present disclosure; and

[0030] Figure 13 A flow chart illustrating an embodiment of a method according to the present disclosure for controlling a wind farm connected to an electric power grid, the wind farm having a plurality of wind turbines. DETAILED DESCRIPTION

[0031] Reference will now be made in detail to embodiments of the present invention, one or more examples of which are illustrated in the accompanying drawings. Each example is provided by way of explanation of the present invention, rather than by way of limitation. In fact, it will be apparent to those skilled in the art that various modifications and variations may be made in the present invention without departing from the scope or spirit of the present invention. For example, a feature illustrated or described as part of one embodiment may be used together with another embodiment to produce yet another embodiment. Therefore, it is intended that the present invention covers such modifications and variations as fall within the scope of the appended claims and their equivalents.

[0032] Grid-forming inverter-based resources (GFM IBRs) have control functionality that mimics the physical aspects of synchronous machines, including inertial power regulators. Therefore, the present disclosure relates to a control strategy in which, for example, in a power plant such as a wind farm, GFM IBRs with the ability to mimic the inertial power response of synchronous machines are enabled to rapidly respond to grid frequency disturbances in an autonomous manner. Furthermore, in embodiments, during transient events, i.e., under- and over-frequency periods, the inertial power response of the GFM IBRs can be constrained within limits set by a plant-level controller to meet the required inertial power and energy at the plant's point of interconnection. Using the proposed control scheme, each GFM IBR in a power plant can independently detect transient events and respond rapidly, e.g., without waiting for prompts from the plant-level controller, without exceeding the inertial power limits. Thus, in embodiments, the plant's aggregate inertial power response profile is coordinated by the plant-level controller to meet one or more grid code requirements and / or the electricity market at the point of interconnection (POI) throughout the frequency disturbance event. During this time, each independent response in the GFMIBR functions in response to the grid frequency while constraining its response to the continuous power limit specified by the plant-level controller. It should be understood that the inverter-based resources described herein may include, but are not limited to, wind turbine power systems, solar power systems, energy storage power systems, or combinations thereof.

[0033] Referring now to the accompanying drawings, Figure 4 A perspective view of one embodiment of a wind turbine 10 according to the present disclosure is illustrated. As shown, the wind turbine 10 may generally include a tower 12 extending from a support surface 14, a nacelle 16 mounted on the tower 12, and a rotor 18 coupled to the nacelle 16. The rotor 18 includes a rotatable hub 20 and at least one rotor blade 22 coupled to the hub 20 and extending outwardly from the hub 20. For example, in the illustrated embodiment, the rotor 18 includes three rotor blades 22. However, in alternative embodiments, the rotor 18 may include more or less than three rotor blades 22. Each rotor blade 22 may be spaced about the hub 20 to facilitate rotating the rotor 18 so that kinetic energy can be converted from the wind into usable mechanical energy, and subsequently into electrical energy. For example, the hub 20 may be rotatably coupled to a generator 24 ( Figure 5 ) to allow the generation of electrical energy.

[0034] The wind turbine 10 may also include a wind turbine controller 26 centralized within the nacelle 16. However, in other embodiments, the controller 26 may be located within any other component of the wind turbine 10 or at a location external to the wind turbine 10. Furthermore, the controller 26 may be communicatively coupled to any number of components of the wind turbine 10 in order to control the operation of such components and / or implement corrective or control actions. Thus, the controller 26 may include a computer or other suitable processing unit. Thus, in several embodiments, the controller 26 may include appropriate computer-readable instructions that, when implemented, configure the controller 26 to perform a variety of different functions, such as receiving, transmitting, and / or executing wind turbine control signals. Thus, the controller 26 may generally be configured to control various operating modes (e.g., startup or shutdown sequences), derate or uprate the wind turbine, and / or individual components of the wind turbine 10.

[0035] Now see Figure 5 , diagram Figure 4 , a simplified interior view of an embodiment of a nacelle 16 of a wind turbine 10 is shown in FIG. As shown, a generator 24 may be disposed within the nacelle 16 and supported atop a base plate 46. Typically, the generator 24 may be coupled to the rotor 18 for generating electrical power from the rotational energy generated by the rotor 18. For example, as shown in the illustrated embodiment, the rotor 18 may include a rotor shaft 34 coupled to the hub 20 for rotation therewith. The rotor shaft 34 may, in turn, be rotatably coupled to a generator shaft 36 of the generator 24 via a gearbox 38. As is generally understood, the rotor shaft 34 may provide a low-speed, high-torque input to the gearbox 38 in response to rotation of the rotor blades 22 and the hub 20. The gearbox 38 may then be configured to convert the low-speed, high-torque input into a high-speed, low-torque output to drive the generator shaft 36, and thereby drive the generator 24.

[0036] Wind turbine 10 may also include one or more pitch drive mechanisms 32 communicatively coupled to wind turbine controller 26, wherein each pitch adjustment mechanism 32 is configured to rotate a pitch bearing 40 and, thereby, an individual rotor blade 22 about its respective pitch axis 28. Additionally, as shown, wind turbine 10 may include one or more yaw drive mechanisms 42 configured to change the angle of nacelle 16 relative to the wind (e.g., by engaging a yaw bearing 44 of wind turbine 10 disposed between nacelle 16 and tower 12 of wind turbine 10).

[0037] In addition, the wind turbine 10 may also include one or more sensors 66, 68 for monitoring various wind conditions of the wind turbine 10. For example, the incoming wind direction 52, wind speed, or any other suitable wind condition near the wind turbine 10 may be measured, for example, using a suitable weather sensor 66. Suitable weather sensors may include, for example, a light detection and ranging ("LIDAR") device, a sound detection and ranging ("SODAR") device, an anemometer, a wind vane, a barometer, a radar device (e.g., a Doppler radar device), or any other sensing device now known in the art or later developed that can provide wind direction information. Additional sensors 68 may also be utilized to measure additional operating parameters of the wind turbine 10, such as voltage, current, vibration, etc., as described herein.

[0038] Now refer to Figure 6 , a schematic diagram illustrating one embodiment of a wind turbine power system 100 according to aspects of the present disclosure. Although reference will generally be made herein to Figure 4 The present disclosure is described with respect to the wind turbine 10 shown in FIG. 1 , but one of ordinary skill in the art, using the disclosure provided herein, will appreciate that aspects of the present disclosure may also be applied to other power generation systems and, as noted above, the invention is not limited to wind turbine systems.

[0039] exist Figure 6 In the embodiment and as described above, the wind turbine 10 ( Figure 4 ) can optionally be coupled to a gearbox 38, which in turn is coupled to a generator 102, which can be a doubly fed induction generator (DFIG). As shown, the DFIG 102 can be connected to a stator bus 104. Additionally, as shown, a power converter 106 can be connected to the DFIG 102 via a rotor bus 108 and to the stator bus 104 via a line-side bus 110. Thus, the stator bus 104 can provide output multi-phase power (e.g., three-phase power) from the stator of the DFIG 102, while the rotor bus 108 can provide output multi-phase power (e.g., three-phase power) from the rotor of the DFIG 102. The power converter 106 can also include a rotor-side converter (RSC) 112 and a line-side converter (LSC) 114. The DFIG 102 is coupled to the rotor-side converter 112 via the rotor bus 108. Additionally, RSC 112 is coupled to LSC 114 via a DC link 116, across which is a DC link capacitor 118. LSC 114 is in turn coupled to line-side bus 110.

[0040] The RSC 112 and the LSC 114 can be configured for a normal mode of operation in a three-phase pulse width modulation (PWM) arrangement using one or more switching devices, such as insulated gate bipolar transistor (IGBT) switching devices. Additionally, the power converter 106 can be coupled to a converter controller 120 to control the operation of the rotor-side converter 112 and / or the line-side converter 114, as described herein. It should be noted that the converter controller 120 can be configured as an interface between the power converter 106 and the turbine controller 26 and can include any number of control devices.

[0041] In a typical configuration, various line contactors and circuit breakers (including, for example, grid breaker 122) may also be included for isolating various components necessary for normal operation of DFIG 102 during connection to and disconnection from a load (e.g., power grid 124). For example, system circuit breaker 126 may couple system bus 128 to transformer 130, which may be coupled to power grid 124 via grid breaker 122. In alternative embodiments, fuses may replace some or all of the circuit breakers.

[0042] In operation, the alternating current generated at the DFIG 102 by the rotating rotor 18 is provided to the power grid 124 via a dual path defined by the stator bus 104 and the rotor bus 108. On the rotor bus side 108, sinusoidal multi-phase (e.g., three-phase) alternating current (AC) power is provided to the power converter 106. The rotor-side converter 112 converts the AC power provided from the rotor bus 108 into direct current (DC) power and provides the DC power to the DC link 116. As is generally understood, the switching elements (e.g., IGBTs) used in the bridge circuit of the rotor-side converter 112 can be modulated to convert the AC power provided from the rotor bus 108 into DC power suitable for the DC link 116.

[0043] Additionally, line-side converter 114 converts the DC power on DC link 116 into AC output power suitable for power grid 124. Specifically, switching elements (e.g., IGBTs) used in the bridge circuit of line-side converter 114 may be modulated to convert the DC power on DC link 116 into AC power on line-side bus 110. The AC power from power converter 106 may be combined with power from the stator of DFIG 102 to provide multi-phase power (e.g., three-phase power) having a frequency substantially maintained at the frequency of power grid 124 (e.g., 50 Hz or 60 Hz).

[0044] Additionally, various circuit breakers and switches (e.g., grid breaker 122, system breaker 126, stator synchronizing switch 132, converter breaker 134, and line contactor 136) may be included in wind turbine power system 100 to connect or disconnect corresponding buses, for example, when excessive current may flow and damage components of wind turbine power system 100 or for other operational considerations. Additional protection components may also be included in wind turbine power system 100.

[0045] In addition, the power converter 106 can receive control signals from, for example, the turbine controller 26 via the converter controller 120. The control signals can be based on, among other things, sensed states or operating characteristics of the wind turbine power system 100. Generally, the control signals provide control over the operation of the power converter 106. For example, feedback in the form of sensed speed of the DFIG 102 can be used to control the conversion of output power from the rotor bus 108 to maintain a proper and balanced multi-phase (e.g., three-phase) power supply. Other feedback from other sensors can also be used by the controller(s) 120, 26 to control the power converter 106, including, for example, stator and rotor bus voltage and current feedback. Using various forms of feedback information, switching control signals (e.g., gate timing commands for the IGBTs), stator synchronization control signals, and circuit breaker signals can be generated.

[0046] Power converter 106 also compensates or adjusts the frequency of the three-phase power from the rotor for variations in, for example, wind speed at hub 20 and rotor blades 22. Thus, the mechanical and electrical rotor frequencies are decoupled, and electrical stator and rotor frequency matching is facilitated substantially independent of mechanical rotor speed.

[0047] Under certain conditions, the bidirectional nature of power converter 106, and in particular the bidirectional nature of LSC 114 and RSC 112, facilitates feeding at least some of the generated electrical power back into the generator rotor. More specifically, electrical power can be transmitted from stator bus 104 to line-side bus 110, and then through line contactor 136 and into power converter 106, in particular LSC 114, which acts as a rectifier and rectifies the sinusoidal three-phase AC power into DC power. The DC power is transmitted into DC link 116. Capacitor 118 facilitates mitigating DC link voltage amplitude variations by facilitating mitigation of DC ripple sometimes associated with three-phase AC rectification.

[0048] The DC power is then transmitted to RSC 112, which converts the DC power into three-phase sinusoidal AC power by regulating voltage, current, and frequency. This conversion is monitored and controlled via converter controller 120. The converted AC power is transmitted from RSC 112 to the generator rotor via rotor bus 108. In this way, generator reactive power control is facilitated by controlling rotor current and voltage.

[0049] Now refer to Figure 7 , the wind turbine system 100 described herein may be part of a wind farm 150. As shown, the wind farm 150 may include a plurality of wind turbines 152, including the wind turbine 10 described above, and an overall farm-level controller 156. For example, as shown in the illustrated embodiment, the wind farm 150 includes twelve wind turbines, including the wind turbine 10. However, in other embodiments, the wind farm 150 may include any other number of wind turbines, such as fewer than twelve wind turbines or more than twelve wind turbines. In one embodiment, the turbine controllers of the plurality of wind turbines 152 are communicatively coupled to the farm-level controller 156, for example, via a wired connection, such as by connecting the turbine controller 26 via a suitable communication link 154 (e.g., a suitable cable). Alternatively, the turbine controllers may be communicatively coupled to the farm-level controller 156 via a wireless connection, such as by using any suitable wireless communication protocol known in the art. In further embodiments, farm-level controller 156 is configured to send and receive control signals to and from each wind turbine 152 , such as, for example, to distribute real and / or reactive power demands across wind turbines 152 of wind farm 150 .

[0050] Now refer to Figure 8 , a schematic diagram illustrating another embodiment of a wind turbine power system 170 according to aspects of the present disclosure. Figure 6 on the contrary, Figure 7The wind turbine power system 170 is a full conversion system. Specifically, as shown, the wind turbine power system 100 includes a generator 172, a generator-side converter 174, and a grid-side converter 176. The wind turbine power system 170 also includes a grid-side controller 178, a generator-side controller 180, and a power grid 182. In addition, as shown, the power grid 182 typically includes a conventional synchronous generator 184 and an electrical load 186. A direct current (DC) link 188 connects the generator-side converter 174 and the grid-side converter 176. Thus, the generator-side converter 174 converts the alternating current (AC) power generated by the generator 172 into DC power. The grid-side converter 176 then converts the DC power into AC power at a frequency compatible with the power grid 182. Thus, in an embodiment, the combination of the grid-side controller 178 and the grid-side converter 176 serves as a current source for the power grid 182. In other words, the grid-side controller 178 controls the phase and amplitude of the output current of the grid-side converter 176.

[0051] Now see Figure 9 , illustrates a block diagram of one embodiment of suitable components that may be included within a controller (e.g., any of the converter controller 120, turbine controller 26, and / or farm-level controller 156 described herein) according to example aspects of the present disclosure. As shown, the controller may include one or more processors 158, computers, or other suitable processing units, and associated memory device(s) 160, which may include suitable computer-readable instructions that, when implemented, configure the controller to perform a variety of different functions, such as receiving, transmitting, and / or executing wind turbine control signals (e.g., performing the methods, steps, calculations, etc. disclosed herein).

[0052] As used herein, the term "processor" refers not only to what is known in the art as an integrated circuit included in a computer, but also to controllers, microcontrollers, microcomputers, programmable logic controllers (PLCs), application-specific integrated circuits, and other programmable circuits. Additionally, the memory device(s) 160 may generally include one or more memory elements, 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, compact disk read-only memory (CD-ROM), magneto-optical disks (MODs), digital versatile disks (DVDs), and / or other suitable memory elements.

[0053] Such memory device(s) 160 may generally be configured to store appropriate computer-readable instructions that, when implemented by the processor(s) 158, configure the controller to perform various functions as described herein. Additionally, the controller may also include a communication interface 162 for facilitating communication between the controller and various components of the wind turbine 10. The interface may include one or more circuits, terminals, pins, contacts, conductors, or other components for sending and receiving control signals. Furthermore, the controller may include a sensor interface 164 (e.g., one or more analog-to-digital converters) for allowing signals transmitted from the sensors 66, 68 to be converted into signals that can be understood and processed by the processor(s) 158.

[0054] Now refer to Figure 10 , provides a flow chart of one embodiment of a method 200 for coordinating the inertial power response of multiple inverter-based resources (which may include grid forming and / or grid tracking capabilities) in a power plant connected to a power grid according to the present disclosure. In general, this document refers to Figure 4-Figure 9 The wind turbine power system 100 and Figure 11-12 The method 200 is described with reference to the control diagrams 300 and 400 of FIG. However, it should be appreciated that the disclosed method 200 may be implemented with any other suitable power generation system having any other suitable configuration. Figure 10 For the purpose of illustration and discussion, the steps performed in a particular order are depicted, but the methods discussed herein are not limited to any particular order or arrangement. Using the disclosure provided herein, those skilled in the art will appreciate that the various steps of the methods disclosed herein may be omitted, rearranged, combined, and / or modified in various ways without departing from the scope of the present disclosure.

[0055] As shown at (202), the method 200 includes receiving, via a plant-level controller of the power plant, at least one of a desired plant inertia or a desired plant inertia power capability. As shown at (204), the method 200 includes continuously determining, via the plant-level controller, at least one of an inertia power limit, a virtual inertia setting, or a real power reference change and sending it to each of a plurality of inverter-based resources. As shown at (206), the method 200 includes coordinating, via the plant-level controller, an inertia power response of the power plant to meet at least one of the desired plant inertia or the desired plant inertia power capability by allowing a respective controller of each of the plurality of inverter-based resources to independently respond to a grid frequency event without exceeding the inertia power limit.

[0056] The inertia of a power plant (or virtual inertia) is a common term used in the art and reflects either the physical inertia of a conventional synchronous generator or the controller settings in a GFM IBR which may be intended to mimic the physical characteristics of a synchronous machine. The inertial response of these systems is characterized by a change in internal speed or frequency which is proportional to the integral of the power imbalance. This change in internal speed or frequency causes a change in angle and thus in active power. In a GFL system, a pseudo-inertial response may be provided based on a predetermined relationship between frequency feedback and temporary changes in the power set point of the inverter-based resource (e.g. these may also be referred to as Fast Frequency Response (FFR) control functions, see e.g. Figure 12 ). This GFL inertial response may be affected by frequency deadband and / or time delay. Inertial power capability refers to the IBR, which is the amount of power change from the initial condition for which the inertial response can be maintained before stopping the inertial response or constraining the inertial response in some other way. The inertial response may need to be constrained to comply with various equipment limitations (e.g., current limits or mechanical limitations of wind turbines) or to avoid tripping the resource. Typically, an inertial response occurs when the grid frequency changes suddenly, due to a loss of load within the grid or a tripping of a generator within the grid.

[0057] In addition, reference Figure 11-12 Can better understand Figure 10 Method 200. More specifically, as Figure 11 and Figure 12 As shown in FIG, a system is provided for coordinating multiple inverter-based resources in a power plant connected to a power grid. Figure 12 ) of the inertial power response of the plant-level controller 302 ( Figure 11 ). Thus, as shown, the plant-level controller 302 may include, for example, a plant inertia response coordinator module 304, an inertia power limit allocation module 306, an inertia power capacity aggregator module 308, a plant power regulator 310, and an active power allocation module 312.

[0058] Therefore, in an embodiment, based on the expected plant inertia response reference 314 (eg, ΔP InerRef ), the plant inertia response coordinator module 304 of the plant-level controller 302 is configured to calculate the capacity adjustment signal 334 (eg, ΔP InerCapAdj For example, in an embodiment, when the potential plant inertia capacity and the predicted plant inertia response 314 (eg, ΔP InerRef ) is insufficient, the capacity adjustment signal 334 (eg, ΔP InerCapAdj ) can be calculated as a non-zero value. In this particular embodiment, as shown, the plant power regulator 310 is configured to provide a power supply to the grid operator based on a power reference 332 (e.g., P Ref) and the capacity adjustment signal 334 (eg, ΔP ) from the plant inertial response coordinator module 304 . InerCapAdj ) to receive input 336. In such an embodiment, for example, capacity adjustment signal 334 allows power reference 332 to be adjusted based on the capacity of the inverter-based resources in the power plant to generate an inertial power response. For example, it may be beneficial to reduce the steady-state power output of the power plant during periods of high output to allow the inverter-based resources to operate further away from their own equipment limits, thereby increasing the inertial power capability.

[0059] Thus, in an embodiment, the plant power regulator 310 of the plant-level controller 302 regulates the power plant to an adjusted active power reference 336. The adjusted active power from the plant power regulator 310, used to implement a desired inertial capacity adjustment signal 334, is distributed by the active power distribution module 312 to each of the plurality of grid-forming and grid-tracking inverter-based resources in the plant. The active power commands for each of the inverter-based resources are communicated to the turbine controllers 406 and 408 of the GFM control 402 and the GFL control 404. The capacity adjustment signal 334 is continuously distributed to all inverter-based resources in the power plant via the power command signal 330 (e.g., Pcmd(i)). In certain embodiments, for example, the desired capacity adjustment signal 334 is configured to be distributed to each of the GFM inverter-based resources and / or the GFL inverter-based resources based on one or more steady-state power distribution signals 338 received from them. In such an embodiment, for example, the steady-state power allocation signal 338 may relate to the individual possible / potential power generation capacity, online status, etc. of the inverter-based resources. In addition, as shown, the active power allocation module 312 may also receive an inertia capability-based allocation bias signal 340 (e.g., InerTurbAdjBias(i)) generated from the plant inertia response coordinator module 304 (e.g., InerTurbAdjBias(i)), which may be used with the steady-state power allocation signal 338 to allocate the required adjustments to each of the plurality of GFM inverter-based resources accordingly (i.e., before a frequency disturbance event occurs). The inertia capability-based allocation bias signal 340 (e.g., InerTurbAdjBias(i)) allows for selection of inverter-based resources within the power plant that are potentially manipulated by the plant-level controller 302 to achieve a desired inertia capacity deficit (e.g., ΔP) reflected in the capacity adjustment signal 334. InerCapAdj ).

[0060] In addition, if Figure 11As shown in FIG, the plant-level controller 302 is configured to, upon receiving an indication of a frequency event occurring in the power plant, continuously determine and send a corresponding distributed inertia power limit 326, 328 to each of the plurality of grid-forming inverter-based resources. Thus, in an embodiment, the plant-level controller 302's plant inertia response coordinator module 304 is configured to receive a predicted inertia response 314 (e.g., ΔP InerRef ), one or more limits 316, 318 from the inertial power capacity aggregator module 308 (eg, ΔP AggPosInerCap and ΔP AggPosInerCap ), and / or one or more signals 320 from a local controller 402 of each of a plurality of grid forming (GFM) inverter-based resources (also referred to herein as GFM controls 402) or a local controller 404 of one or more grid tracking (GFL) inverter-based resources (also referred to herein as GFL controls 404). In such an embodiment, for example, the signal(s) 320 may include an online status or availability of the inverter-based resources in the power plant, an inertial power capability of the inverter-based resources in the power plant, an inertial energy content of the inverter-based resources in the power plant, and / or a possible power of the inverter-based resources in the power plant.

[0061] Using various inputs, the plant inertia response coordinator module 304 of the plant-level controller 302 is configured to determine the limits 322, 324 (eg, ΔP Iner Max and ΔP Iner Min Thus, as shown, the limits 322, 324 may be sent to the inertia power limit allocation module 306 of the plant level controller 302 for use in determining the inertia power limit that may be allocated to the GFM control 402 ( Figure 12 ) and the corresponding distributed inertial power limits 326 , 328 (eg, ΔP ) of the GFL control 404 . Iner_Max(l) and ΔP Iner_Min(l) ). In an embodiment, for example, the respective distributed inertial power limits 326, 328 may include a maximum inertial power limit ΔP Iner_Max(l) and minimum inertia power limit ΔP Iner_Min(l) .

[0062] Thus, the plant inertia response coordinator module 304 and the inertia power limit allocation module 306 of the plant-level controller 302 are configured to continuously determine corresponding allocated inertia power limits 326, 328 (eg, ΔP Iner_Max(l) and ΔP Iner_Min(l)) and sends it to each of the plurality of grid-forming inverter-based resources. In certain embodiments, for example, the plant inertia response coordinator module 304 and / or the inertia power limit allocation module 306 may continuously receive the signal 338 from the GFM control 402 and / or the GFL control 404 and, accordingly, may continuously determine the corresponding distributed inertia power limits 326, 328 for the GFM control 402 and / or the GFL control 404 based on the signal(s) 338. Furthermore, in certain embodiments, for example, GFM inverter-based resources with high energy availability and low power production (i.e., high generator speed) may be prioritized with a higher inertia power limit.

[0063] Thus, in certain embodiments, the plant-level controller 302 is configured to coordinate the inertial power response of the power plant during a frequency event by allowing the GFM control 402 to independently detect and quickly respond to the frequency event without exceeding the corresponding distributed inertial power limit to meet one or more grid code requirements and / or electricity markets. In another embodiment, if at any time there is a gap in the potential inertial power that can be generated or absorbed to meet the predefined inertial power reference specified by the grid code requirement(s) and / or electricity market, the plant-level controller 302 may adjust operations so as to meet the predefined inertial power reference specified by the grid code requirement(s) and / or electricity market. ref ) to increase the plant's inertial power capability.

[0064] Now special reference Figure 12 , inverter-based resources from multiple grids (from Figure 11 ) can initially serve as the corresponding distributed inertial power limit for the GFM's inverter-based resources to constrain the amount of inertial power that can be injected into the power grid upon detection of a frequency event. Furthermore, in an embodiment, the GFM control 402 is configured to independently detect frequency events by monitoring one or more grid feedbacks from the power grid. In such an embodiment, for example, the grid feedback(s) may include phase angle, frequency, voltage, current, or a combination thereof. Thus, upon detection of a frequency event, the GFM control 402 is configured to instantaneously inject a corresponding amount of inertial power within the corresponding distributed inertial power limits 326, 328, as required by the frequency deviation and continuously determined and updated as described herein. In such an embodiment, for example, the GFM control 402 can independently detect and quickly respond to frequency events without exceeding the corresponding distributed inertial power limits 326, 328, without having to wait for a signal from the plant-level controller 302.

[0065] Inverter-based resources can continuously provide their virtual inertia capabilities or inertia power capabilities back to plant-level control. These capabilities may be constrained due to operating point, equipment limitations, and stored energy (via batteries or stored kinetic energy in the wind turbine). For example, if the inverter-based resource is a wind turbine, its positive inertia power capability may be more constrained at low operating speeds due to the relatively low stored energy in the rotating mass and operating relatively close to the underspeed trip level.

[0066] Now refer to Figure 13 , provides a flow chart of another embodiment of a method 500 for controlling a wind farm connected to a power grid according to the present disclosure. In such an embodiment, for example, the wind farm includes a plurality of wind turbines, wherein at least one of the plurality of wind turbines is a grid-forming wind turbine. In general, this document refers to Figure 4-Figure 9 The wind turbine power system 100 and Figure 11-12 The method 500 is described with reference to the control diagrams 300 and 400 of FIG. However, it should be appreciated that the disclosed method 200 may be implemented with any other suitable power generation system having any other suitable configuration. Figure 13 For the purpose of illustration and discussion, the steps performed in a particular order are depicted, but the methods discussed herein are not limited to any particular order or arrangement. Using the disclosure provided herein, those skilled in the art will appreciate that the various steps of the methods disclosed herein may be omitted, rearranged, combined, and / or modified in various ways without departing from the scope of the present disclosure.

[0067] As shown at (502), method 500 includes receiving at least one of a desired instantaneous power or energy availability for a wind farm. As shown at (504), method 500 includes receiving at least one of transient power or energy availability feedback from each of a plurality of wind turbines. As shown at (506), method 500 includes receiving a steady-state power capability from each of a plurality of wind turbines. As shown at (508), method 500 includes determining an expected portion of the desired instantaneous power or energy availability of the wind farm to be satisfied by each of the plurality of wind turbines based on the transient power or energy availability feedback from each of the plurality of wind turbines. As shown at (510), method 500 includes determining at least one of a power limit for each of the plurality of wind turbines and a wind farm active power reduction set point based on the steady-state power capability from each of the plurality of wind turbines and the expected portion of the desired transient power or energy availability of the wind farm to be satisfied by each of the plurality of wind turbines based on the transient power or energy availability feedback from each of the plurality of wind turbines. As shown at (512), method 500 includes controlling the wind farm based on the power limit to provide a desired transient power or energy to the power grid when a grid frequency or phase angle change occurs.

[0068] Further aspects of the invention are provided by the subject matter of the following clauses:

[0069] A method for coordinating the inertial power response of a plurality of inverter-based resources in a power plant connected to an electric power grid, the method comprising: receiving, via a plant-level controller of the power plant, at least one of a desired plant inertia or a desired plant inertia power capability; continuously determining, via the plant-level controller, and sending, to each of the plurality of inverter-based resources, at least one of an inertia power limit, a virtual inertia setting, or an active power reference change; and coordinating, via the plant-level controller, the inertial power response of the power plant to meet at least one of the desired plant inertia or the desired plant inertia power capability by allowing a corresponding controller of each of the plurality of inverter-based resources to independently respond to a grid frequency event without exceeding the inertia power limit.

[0070] The method of any preceding clause, further comprising assigning, via a plant-level controller, an inertia power limit to each of the plurality of grid forming inverter-based resources based on at least one of a potential power of each of the plurality of grid forming inverter-based resources or an online status or availability of one or more of the plurality of grid forming inverter-based resources.

[0071] A method as described in any preceding clause, wherein the inertia power limit constrains the amount of inertia power that can be injected into the power grid for a grid frequency event.

[0072] A method as in any preceding clause, further comprising injecting, via a respective controller of each of the plurality of inverter-based resources, a required corresponding amount of inertial power based on a response of a respective inertial power regulator to the virtual inertial setting and within the inertial power limit.

[0073] A method according to any preceding clause, wherein continuously determining and sending at least one of an inertia power limit, a virtual inertia setting, or an active power reference change to each of a plurality of inverter-based resources further comprises: continuously receiving one or more signals from each of a plurality of inverter-based resources; and continuously determining the inertia power limit, the virtual inertia setting, or the active power reference change for each of the plurality of inverter-based resources based on the one or more signals.

[0074] A method as described in any preceding clause, wherein the one or more signals from each of the plurality of inverter-based resources include at least one of an online status or availability of one or more of the plurality of inverter-based resources, an inertial power capability of one or more of the plurality of inverter-based resources, an inertial energy capability of one or more of the plurality of inverter-based resources, a maximum virtual inertial capability, or a possible power of one or more of the plurality of inverter-based resources.

[0075] The method according to any of the preceding clauses further includes assigning, via a plant-level controller, a higher inertia power limit to inverter-based resources formed by a grid having a higher inertia power capability to compensate for other inverter-based resources having a lower inertia power capability or being offline, thereby enabling the net plant inertia capability of the power plant to meet the desired plant inertia power capability.

[0076] A method as defined in any preceding clause, further comprising allocating, via the plant-level controller, a reduced active power reference to a portion of the inverter-based resources to meet a desired inertial power capability of the plant.

[0077] A method as defined in any preceding clause, further comprising notifying a grid operator via a plant level controller if the desired plant inertia power capability or inertia power capability cannot be met by the power plant.

[0078] The method of any preceding clause, further comprising continuously determining and sending an inertia power limit to each of the plurality of inverter-based resources based on one or more grid code requirements of the power grid.

[0079] A method as in any preceding clause, wherein the inertia power limit comprises a maximum inertia power limit and a minimum inertia power limit.

[0080] A method as in any preceding clause, wherein grid-forming inverter-based resources of the plurality of inverter-based resources independently detect and quickly respond to grid frequency events up to inertia power limits without awaiting a signal from a plant-level controller.

[0081] The method of any preceding clause, wherein the inverter-based resource comprises at least one of a wind turbine power system, a solar power system, an energy storage power system, or a combination thereof.

[0082] A system for coordinating the inertial power response of a plurality of grid-forming inverter-based resources in a power plant connected to an electric power grid, the system comprising: a plurality of local controllers; and a plant-level controller communicatively coupled to the plurality of local controllers, the plant-level controller comprising at least one processor configured to perform a plurality of operations, the plurality of operations comprising: receiving at least one of a desired plant inertia or a desired plant inertia power capability; continuously determining and sending at least one of an inertia power limit, a virtual inertia setting, or an active power reference change to each of the plurality of inverter-based resources; and coordinating the inertial power response of the power plant to meet at least one of the desired plant inertia or the desired plant inertia power capability by allowing the respective controllers of each of the plurality of inverter-based resources to independently respond to grid frequency events without exceeding the inertia power limit.

[0083] The system of any preceding clause, wherein the plurality of operations further comprises assigning the inertia power limit to each of the plurality of grid forming inverter-based resources based on at least one of a possible power of each of the plurality of grid forming inverter-based resources or an online status or availability of one or more of the plurality of grid forming inverter-based resources.

[0084] A system as in any preceding clause, wherein the inertia power limit constrains the amount of inertia power that can be injected into the power grid for a grid frequency event.

[0085] A system according to any preceding clause, wherein the plurality of operations further comprises injecting, via a respective controller of each of the plurality of inverter-based resources, a corresponding amount of inertia power required based on a response of a respective inertia power regulator to the virtual inertia setting and within the inertia power limit.

[0086] A system as described in any preceding clause, wherein continuously determining and sending at least one of an inertia power limit, a virtual inertia setting, or an active power reference change to each of the plurality of inverter-based resources further comprises: continuously receiving one or more signals from each of the plurality of inverter-based resources; and continuously determining the inertia power limit of each of the plurality of inverter-based resources based on the one or more signals.

[0087] A system as described in any preceding clause, wherein the one or more signals from each of the plurality of inverter-based resources include at least one of the online status or availability of one or more of the plurality of inverter-based resources, the inertial power capability of one or more of the plurality of inverter-based resources, the inertial energy content of one or more of the plurality of inverter-based resources, or the possible power of one or more of the plurality of inverter-based resources.

[0088] A method for controlling a wind farm connected to an electric power grid, the wind farm having a plurality of wind turbines, wherein at least one of the plurality of wind turbines is a grid-forming wind turbine, the method comprising: receiving at least one of a desired transient power or energy availability for the wind farm; receiving at least one of transient power or energy availability feedback from each of the plurality of wind turbines; receiving a steady-state power capability from each of the plurality of wind turbines; determining an expected portion of the desired transient power or energy availability of the wind farm to be met by each of the plurality of wind turbines based on the transient power or energy availability feedback from each of the plurality of wind turbines; determining at least one of a power limit and a wind farm active power reduction set point for each of the plurality of wind turbines based on the steady-state power capability from each of the plurality of wind turbines and the expected portion of the desired transient power or energy availability of the wind farm to be met by each of the plurality of wind turbines based on the transient power or energy availability feedback from each of the plurality of wind turbines; and controlling the wind farm to provide the desired transient power or energy to the electric power grid based on the power limit when a grid frequency or phase angle change occurs.

[0089] This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the invention is defined by the claims and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they include structural elements that do not differ substantially from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal language of the claims.

Claims

1. A method of coordinating the inertial power response of a plurality of inverter-based resources in a power plant connected to a power grid, the method comprising: receiving, via a plant-level controller of the power plant, at least one of a desired plant inertia or a desired plant inertia power capability; continuously determining and sending, via the plant-level controller, at least one of an inertia power limit, a virtual inertia setting, or an active power reference change to each of the plurality of inverter-based resources; as well as The inertial power response of the power plant is coordinated via the plant-level controller to meet at least one of the desired plant inertia or the desired plant inertia power capability by allowing a respective controller of each of the plurality of inverter-based resources to independently respond to a grid frequency event without exceeding the inertia power limit.

2. The method of claim 1 , further comprising assigning, via the plant-level controller, the inertia power limit to each of the plurality of grid forming inverter-based resources based on at least one of a possible power of each of the plurality of grid forming inverter-based resources or an online status or availability of one or more of the plurality of grid forming inverter-based resources.

3. The method according to claim 2, wherein: The inertia power limit constrains the amount of inertia power that can be injected into the power grid for a grid frequency event.

4. The method of claim 1 , further comprising injecting, via the respective controller of each of the plurality of inverter-based resources, a required corresponding amount of the inertia power based on a response of a respective inertia power regulator to the virtual inertia setting and within the inertia power limit.

5. The method according to claim 1, wherein Continuously determining and sending at least one of the inertia power limit, the virtual inertia setting, or the active power reference change to each of the plurality of inverter-based resources further comprises: continuously receiving one or more signals from each of the plurality of inverter-based resources; and The inertia power limit, the virtual inertia setting, or the active power reference change is continuously determined for each of the plurality of inverter-based resources based on the one or more signals.

6. The method according to claim 5, wherein: The one or more signals from each of the plurality of inverter-based resources include at least one of an online status or availability of one or more of the plurality of inverter-based resources, an inertial power capability of one or more of the plurality of inverter-based resources, an inertial energy capability of one or more of the plurality of inverter-based resources, a maximum virtual inertial capability, or a possible power of one or more of the plurality of inverter-based resources.

7. The method of claim 5 , further comprising assigning, via the plant-level controller, a higher inertia power limit to inverter-based resources forming a grid having a higher inertia power capability to compensate for other inverter-based resources having a lower inertia power capability or being offline, thereby enabling the net plant inertia capability of the power plant to meet the desired plant inertia power capability. 8 . The method of claim 5 , further comprising assigning, via the plant-level controller, a reduced active power reference to a portion of the inverter-based resources to meet the desired inertia power capability of the plant.

9. The method of claim 5, further comprising notifying a grid operator via the plant-level controller if the desired plant inertia power capability or the inertia power capability cannot be met by the power plant.

10. The method of claim 1, further comprising continuously determining and sending the inertia power limit to each of the plurality of inverter-based resources based on one or more grid code requirements of the power grid.

11. The method according to claim 1, wherein The inertia power limit includes a maximum inertia power limit and a minimum inertia power limit.

12. The method according to claim 1, wherein The grid-forming inverter-based resources of the plurality of inverter-based resources independently detect and quickly respond to the grid frequency event without exceeding the inertia power limit and without waiting for a signal from the plant-level controller.

13. The method according to claim 1, wherein The inverter-based resource includes at least one of a wind turbine power system, a solar power system, an energy storage power system, or a combination thereof.

14. A system for coordinating the inertial power response of a plurality of grid-forming inverter-based resources in a power plant connected to a power grid, the system comprising: Multiple local controllers; as well as a plant-level controller communicatively coupled to the plurality of local controllers, the plant-level controller comprising at least one processor configured to perform a plurality of operations comprising: receiving at least one of a desired plant inertia or a desired plant inertia power capability; continuously determining and sending at least one of an inertia power limit, a virtual inertia setting, or an active power reference change to each of the plurality of inverter-based resources; and The inertial power response of the power plant is coordinated to meet at least one of the desired plant inertia or the desired plant inertia power capability by allowing a respective controller of each of the plurality of inverter-based resources to independently respond to a grid frequency event without exceeding the inertia power limit.

15. The system according to claim 14, wherein: The plurality of operations further include assigning the inertia power limit to each of the plurality of grid forming inverter-based resources based on at least one of a potential power of each of the plurality of grid forming inverter-based resources or an online status or availability of one or more of the plurality of grid forming inverter-based resources.

16. The system according to claim 15, wherein: The inertia power limit constrains the amount of inertia power that can be injected into the power grid for a grid frequency event.

17. The system of claim 14, wherein: The plurality of operations further include injecting, via the respective controller of each of the plurality of inverter-based resources, a required corresponding amount of the inertia power based on a response of a respective inertia power regulator to the virtual inertia setting and within the inertia power limit.

18. The system of claim 14, wherein: Continuously determining and sending at least one of the inertia power limit, the virtual inertia setting, or the active power reference change to each of the plurality of inverter-based resources further comprises: continuously receiving one or more signals from each of the plurality of inverter-based resources; and The inertial power limit of each of the plurality of inverter-based resources is continuously determined based on the one or more signals.

19. The system according to claim 18, wherein: The one or more signals from each of the plurality of inverter-based resources include at least one of an online status or availability of one or more of the plurality of inverter-based resources, an inertial power capability of one or more of the plurality of inverter-based resources, an inertial energy capability of one or more of the plurality of inverter-based resources, or a possible power of one or more of the plurality of inverter-based resources.

20. A method for controlling a wind farm connected to an electric power grid, the wind farm having a plurality of wind turbines, wherein at least one of the plurality of wind turbines is a grid-forming wind turbine, the method comprising: receiving at least one of a desired instantaneous power or energy availability for the wind farm; receiving at least one of transient power or energy availability feedback from each of the plurality of wind turbines; receiving a steady-state power capability from each of the plurality of wind turbines; determining an expected portion of the desired transient power or energy availability for the wind farm to be satisfied by each of the plurality of wind turbines based on the transient power or energy availability feedback from each of the plurality of wind turbines; determining at least one of a power limit for each of the plurality of wind turbines and a wind farm active power curtailment setpoint based on the steady-state power capability from each of the plurality of wind turbines and the expected portion of the desired transient power or energy availability of the wind farm to be satisfied by each of the plurality of wind turbines based on the transient power or energy availability feedback from each of the plurality of wind turbines; as well as When a grid frequency or phase angle change occurs, the wind farm is controlled based on the power limit to provide desired transient power or energy to the power grid.

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