Active power boost for wind power plants

Abstract

Aspects of the invention relate to a method (100) for controlling one or more wind turbine generators (14). The method (100) comprises receiving (102) a trigger signal, and in response to receiving the trigger signal, implementing (104) an active power boost mode during a predetermined time period. The active power boost mode comprises disregarding (106) further trigger signals; and generating (108) one or more active power upper limits for each of the one or more wind turbine generators (14), wherein the one or more active power upper limits are fixed (110) at an active power boost level that is greater than a nominal active power level of the one or more wind turbine generators (14) at least during a first portion of the predetermined time period.

Description

Technical Field

[0001] This disclosure relates to a method for controlling one or more wind turbine generators, and a power plant controller for implementing the method. Background Technology

[0002] Wind turbine generators are typically limited to their maximum active power output. Maximum active power output is usually the "rated power" of a wind turbine generator, which is the nominal value that the generator can produce over a relatively wide range of wind speeds without excessive mechanical load.

[0003] In some situations, it is useful to increase a generator's active power output beyond its rated power. This can be done by continuously boosting the active power output. A sustainable boost involves increasing the maximum active power beyond the generator's original rated power, but within the generator's overall generating capacity. This type of boost differs from the so-called "over-boost" of wind turbine generators, where the generator's rotor kinetic energy is utilized and released for a rapid burst of active power output, followed by a period of recovery. Instead, this sustainable boost is achieved without the need for recovery.

[0004] While sustainable improvements are useful in themselves, current implementations limit their use in specific energy markets, may result in undesirable mechanical loads on generators, and could lead to imbalances in power generation at wind farms.

[0005] The purpose of this invention is to address one or more drawbacks associated with the prior art. Summary of the Invention

[0006] According to one aspect of the present invention, a method for controlling one or more wind turbine generators is provided. The method includes: receiving a trigger signal indicating that a trigger criterion is met, and implementing an active power boosting mode for a predetermined time period initiated in response to receiving the trigger signal. The active power boosting mode includes: ignoring further trigger signals; and generating one or more active power limits for each of the one or more wind turbine generators. At least during a first portion of the predetermined time period, the one or more active power limits are fixed at an active power boosting level greater than the nominal active power level of the one or more wind turbine generators.

[0007] Active power enhancement level refers to the level achievable by a wind turbine generator within its physical capabilities and without requiring restoration. Active power enhancement level can be considered a sustainable enhancement level above the rated active power level. Active power enhancement level can include active power levels between the rated power level and the maximum power level achievable above the threshold wind speed.

[0008] The nominal active power level can be considered as the original or rated nominal power—the level of active power the turbine operates under normal conditions. This is typically the rated power of the generator at the time of installation. An increase level can be considered as an accrual or new nominal power, making it an increase on the upper limit of active power, rather than generating excess active power beyond the existing maximum value, as in the case known as "over-accrual."

[0009] One or more active power limits may be determined based on multiple factors. In some examples, the active power limit for a generator may be based on a predetermined level for that generator or all generators. In other examples, active power limits may be generated for individual generators based on expected wear and tear and other factors (including wind speed, maximum output power of the generator, and other factors) during the generator's lifespan. In some embodiments, a single power limit may be determined for each generator, while in other embodiments, multiple power limits may be determined for each generator and for each limit and / or for different time periods used by the limits selected based on the state.

[0010] By employing active power boosting modes and their use of triggering criteria, the provision of increased active power levels can be responsive and able to react quickly to demands. Simultaneously, a fixed boosting level ensures that changes in triggering criteria do not lead to fluctuating on / off cycles in the boosting mode, which could subject wind turbine generators to severe mechanical loads. Maintaining a fixed active power level, at least for the first part of the time period, also allows generators, and (when applied to multiple generators) a wider range of power plants, to participate in the ancillary services market over extended periods. For example, it allows participation in markets requiring specific power boosts within a defined time period.

[0011] One or more active power limits may be fixed during the first part by the following steps: activating a first timer and continuing the first part for a predetermined time period; setting the active power limit to an active power increase level; and preventing changes to the active power limit while the first timer is active.

[0012] The predetermined time period may include a second part that is consecutive to the first part. During the second part, one or more active power caps may be fixed at the nominal active power level of one or more wind turbine generators.

[0013] One or more active power limits may be fixed during the second part by the following steps: activating a second timer and continuing the second part for a predetermined period of time; setting the active power limit to a nominal active power level; and preventing changes to the active power limit while the second timer is active.

[0014] The second part, along with the accompanying fixed active power limit setting, further improves the characteristics of the method by incorporating a "down time" during which the upper limit of the wind turbine generator is at its normal level. This allows the wind turbine generator to reach its nominal level for a period of time before re-triggering, thus enabling better control over the generator's behavior.

[0015] The second part and its associated limits also help to comply with operator-set rules, ensuring that the amount of boost time remains below a threshold. For example, the first and second parts, along with the active power limit, can be set such that the cumulative time of the first part is less than or equal to the threshold over the entire time period. The second part can be set to occupy the remaining time. In this way, boost capacity is preserved and evenly distributed throughout the time period.

[0016] The length of the first part can be greater than the length of the second part.

[0017] The scheduled time period may include a first part and a second part.

[0018] The method may include, at the end of a predetermined time period: checking the trigger criteria; if the trigger criteria are still met, re-entering the active power boost mode; or if the trigger criteria are not met, setting the active power limit of one or more wind turbine generators to the nominal active power level of one or more wind turbine generators and waiting for a new trigger signal.

[0019] The triggering criteria can be based on one or more of the measured grid frequency and electricity price.

[0020] Additionally and / or alternatively, triggering criteria may be based on measured wind speed levels. Triggering criteria may include measured wind speeds exceeding wind speed thresholds. Wind speed thresholds may include wind speed levels at which one or more wind turbine generators are capable of producing an increased level of active power.

[0021] Triggering criteria may include a generator’s desired active power level exceeding the active power output that the generator can supply at its nominal rated power. Active power output may be based on the measured wind speed for each generator.

[0022] The active power enhancement level can include the level of active power that a wind turbine generator can supply without consuming the kinetic energy stored in the generator drive system.

[0023] During the active power boost mode, a ramp rate can be applied during the transition between active power limits. In other words, the active power boost level is achieved in stages as the first part of the time period begins. After the first part, the transition from the boost level to the original nominal level is also achieved in stages. The staged transition reduces overshoot in the active power production of wind turbine generators, thereby ensuring that the mechanical load remains at a safe level.

[0024] According to another aspect of the present invention, a power plant controller is provided, the power plant controller including a limit generation unit configured to perform the above-described method.

[0025] The limit generation unit may include a first timer and a second timer.

[0026] The power plant controller may include a distributor. A limit generation unit may be configured to send generated active power limits to the distributor. The distributor may be configured to: receive an active power reference from a power plant comprising multiple wind turbines; determine the active power setpoint of the wind turbine generators; apply the generated active power limits to the active power setpoint of each generator to achieve a restricted active power setpoint; and allocate each restricted active power setpoint to its corresponding wind turbine generator for controlling the active power output of the wind turbine generators.

[0027] A power plant controller may be provided, comprising a limit generation unit configured to generate an active power limit for each of a plurality of wind turbine generators, the active power limit being used to limit the setpoint of the plurality of wind turbine generators, and the limit generation unit including one or more timers activating in response to a trigger signal, wherein when the timers are active, the limit generation unit generates an active power limit at a predetermined value specific to the timer for the duration of the timer.

[0028] The power plant controller described above can be combined with any of the features described above or below.

[0029] Within the scope of this application, it is expressly indicated that aspects, embodiments, examples, and alternatives, and in particular their individual features, given in the foregoing paragraphs, claims, and / or the following description and drawings, may be used independently or combined in any way. That is, all embodiments and / or features of any embodiment may be combined in any way and / or in any combination, unless such features are incompatible. The applicant reserves the right to accordingly amend any originally filed claim or to file any new claim, including the right to modify any originally filed claim to include any feature subordinate to and / or incorporated into any other claim, even if the claim was not initially filed in this manner. Attached Figure Description

[0030] One or more embodiments of the invention will now be described by way of example only, with reference to the accompanying drawings, in which:

[0031] Figure 1 A schematic representation of a power network is shown;

[0032] Figure 2 A block diagram of an active power controller or control function for a power plant controller is shown.

[0033] Figure 3 It shows Figure 2 A block diagram of the active power controller or limit generation unit for control functions;

[0034] Figure 4 An example illustration is shown. Figure 3 The limit value generates a graph of the unit's operation; and

[0035] Figure 5 It shows the use of Figure 2 The flowchart shows the method of using a controller to operate a wind turbine generator. Detailed Implementation

[0036] In general, the invention described herein is a method for controlling a wind turbine generator, and more specifically, a method in which a maximum active power output or active power limit is set and fixed at a level higher than the original nominal or original rated power of each turbine, based on a trigger signal. The maximum output is fixed and maintained for a period of time to prevent repeated and unnecessary switching between different maximum values, which could result in loads being applied to the turbine that are detrimental to its lifespan. The invention may also include another fixed maximum output level at the rated power level for an immediately following period of time, such that the turbine operates at its rated power at least for a short period. This also prevents excessively rapid switching between different maximum values.

[0037] Figure 1A typical architecture is shown in which a wind power plant (WPP) (also referred to as a wind farm or wind farm) is connected to a main power grid as part of a broader power network. As a skilled reader will understand, a WPP includes at least one wind turbine generator (WTG) and is also referred to as a wind farm or wind farm. A WTG is generally referred to as a wind turbine. The example shown is merely representative, and a skilled reader will understand that other specific architectures are feasible, involving wind power plants, power plants using other renewable energy sources (such as solar power plants, bioenergy power plants, or ocean / wave / tidal energy power plants), and hybrid power plants with combinations of different types of renewable energy power plants. Therefore, the invention also relates to conventional renewable energy power plants and renewable energy generators, rather than being specific to wind power plants and generators as shown in the figures. The components of wind power plants and power grids are conventional and therefore familiar to a skilled reader. It is expected that, in addition to… Figure 1 The components shown and described, or as being in Figure 1 The replacement of the components shown and described may include other known components. Such modifications are within the capabilities of a person skilled in the art.

[0038] Figure 1 A power network comprising a WPP 12 and a power plant controller 22 (hereinafter referred to as PPC 22) is shown. The WPP 12 includes multiple WTGs 14. Each of the multiple WTGs 14 converts wind energy into electrical energy, which is transmitted from the WPP 12 as active power and / or current to the main transmission network or main grid 16 for distribution. In this description, each individual generator may be referred to as a "cell".

[0039] Although not shown in this figure, WPP 12 may also include compensation devices (such as a static synchronous compensator (STATCOM) or other types of synchronous compensators) configured to provide reactive power or reactive current support as needed. WPP 12 may also include a battery energy storage system.

[0040] Each of the WTGs 14 is associated with a corresponding WTG controller 15. In some examples, a group of WTGs may share a single semi-centralized WTG controller, resulting in a smaller number of WTG controllers than WTGs. As will be understood by those skilled in the art, the WTG controller 15 can be considered a computer system capable of operating the WTGs 14 in the manner specified herein, and may include multiple modules controlling individual components of the WTGs, or may include only a single controller. The computer system of the WTG controller 15 may operate based on software downloaded to it via a communication network or programmed onto it from a computer-readable storage medium.

[0041] During normal operation of WPP 12, WTG controller 15 operates to fulfill active and reactive current and / or power requests received from PPC 22 to provide frequency and voltage support to the main grid 16. Under special conditions, WTG controller 15 operates to meet predetermined network requirements and also serves to protect WTG 14 from any potentially harmful conditions.

[0042] WPP 12 is connected to the main power grid 16 (also known as the main power network) via connection network 18. WPP 12 and main power grid 16 are connected at interconnection point (PoI) 20, which is the interface between WPP 12 and main power grid 16. PoI 20 may also be referred to as the common connection point, and may be abbreviated as "PCC" or "PoCC".

[0043] The WTGs 14 are interconnected via local power grids 19 (also called local power networks or power plant grids). The function of the local power grid is to transmit power from each of the WTGs 14 to the connection network 18, and then to the main power grid 16.

[0044] The Power Plant Controller (PPC) 22 is connected to the main grid 16 at the Point of Measurement (PoM) 24 and to the WTG controller 15. The PPC 22 serves as the command and control interface between the WPP 12 and the grid 16, and more specifically, between the WPP 12 and the grid operator (such as the Transmission System Operator (TSO) or Distribution System Operator (DSO) 26). The PPC 22 is a suitable computer system for executing the aforementioned control and commands, and therefore includes a processing module 28, a connection module 30, a memory module 32, and a sensing module 34. The PPC 22 can also receive information about the grid 16 and / or local bus, substations, and networks from the energy management system (not shown). The WPP 12 can change its power or current output in response to commands received from the PPC 22.

[0045] As part of its operation, PPC 22 generates and sends a distribution signal to WTG controller 15. WTG controller 15 controls the WTG based on the setpoint contained in the distribution signal.

[0046] During normal operation, PPC 22 operates in one of several modes. One such mode is frequency regulation (also known as frequency control mode), in which PPC 22 issues a distribution signal configured to supply active power to the wider network via WTG 14 to regulate the frequency level of the power network. In another mode, PPC 22 operates to meet the power reference provided by TSO 26. In each of these modes, PPC 22 provides WTG 14 with a signal indicating the active power setpoint and can also distribute signals to suspend or release WTG 14 from a suspended state.

[0047] Figure 2 A schematic representation of the PPC active power control unit 40, also known as the control function, is shown and is included in the processing module 28 of the PPC 22. The control unit 40 is configured to receive or determine an active power reference value and generate multiple active power setpoints for the WTG 14, which together achieve the reference value. The PPC 22 then assigns these setpoints to the WTG controller 15.

[0048] like Figure 2 As shown, the PPC active power control unit 40 includes an active power controller 42. The active power controller 42 receives one or more inputs and generates an active power reference value. The inputs received by the active power controller 42 depend on the operating mode in which the active power controller 42 can operate. The active power controller 42 receives the active power reference value P from the TSO26 configured with a direct active power control mode. ref When the frequency control mode is configured, the active power controller 42 receives the measured frequency F. meas and the measured active power value P meas In this embodiment of the active power controller 42, all these values ​​are provided as inputs, and switching is operable to change the mode. In each mode, the output from the active power controller 42 is a power reference value P. ref_control .

[0049] The active power reference value P from the output of the active power controller 42 ref_control The value is received at differential connection point 44, and the difference between the reference value and the measured active power value of WPP 12 is determined. The output of differential connection point 44 is therefore the active power error value P. error .

[0050] The error value is transmitted to the active power distributor 46. A pause / release controller 48 is also shown in the control unit 40, which also receives the error value and determines whether to pause or release WTG 14 to satisfy the error signal.

[0051] The active power divider 46 receives the error value and determines the setpoint P for each WTG 14. setp_WTGi The setpoint for each WTG 14 is determined based on its capacity. In other words, the distributor 46 receives the value of the available active power of the WTG 14 and limits the setpoint to the maximum value.

[0052] In a conventional controller, the maximum setpoint value will be the rated power of the WTG 14. For example, the rated power can be read by the distributor from a lookup table in the data memory of the rated power for each WTG.

[0053] In this embodiment, the distributor 46 also receives input from the limit generation unit 50. The limit generation unit 50 determines an active power upper limit P for each WTG14. max_WTGi (It can also be referred to as the maximum active power value or output), and this set of values ​​is provided to the distributor 46 to limit the setpoint.

[0054] The following will combine Figures 3 to 5 Describe the operation of limit value generation unit 50. Figure 3 A block diagram of an exemplary limit generation unit 50 is shown. Figure 4 A diagram indicating the operation of generation unit 50 is shown. Figure 5 A flowchart is provided for a method 100 for operating as an overall management limit generation unit 50 and PPC 22.

[0055] exist Figure 3 In this unit, the limit generation unit 50 includes trigger selection logic 52, a boost controller 54, limit selection logic 56, and a limit controller 58. Typically, the boost controller 54 and the limit controller 58 generate a maximum active power value for each wind turbine and input these values ​​into the selection logic 56. The selection logic 56 selects one of these maximum active power values ​​and transmits it to the distributor 46.

[0056] Limit controller 58 is configured to apply predetermined active power limit rules set by the operator of WPP 12. For example, if the maximum active power output of a particular WTG 14 is reduced due to mechanical problems, limit controller 58 can specify a maximum active power lower than the rated power of the WTG. The operation of limit controller 58 is familiar to those skilled in the art and will not be discussed in detail in this application. Limit selection logic 56 is configured to receive the limit determined by limit controller 58. As will be discussed below, if limit selection logic 56 receives a limit for WTG 14 from limit controller 58, that limit will override the limit received from the boost controller 54 of WTG 14.

[0057] The boost controller 54 and trigger selection logic 52 are arranged to work together to generate a maximum active power value based on one or more trigger criteria. Trigger selection logic 52 receives input measurements of trigger parameters from WPP 12 and / or TSO 26. Figure 3 In this embodiment, the triggering parameters are the grid frequency and the electricity price. In other embodiments, alternative or different triggering parameters may be used.

[0058] Based on the measured input of the trigger parameters, trigger selection logic 52 determines whether a trigger criterion is met. Trigger criteria may include, for example, a threshold value exceeding or being exceeded by the average of multiple measurements over a predetermined time period. In a specific example, a frequency band between 49.5 and 50.5 Hz can be specified for a 50 Hz power grid, where any deviation outside this band would result in the trigger criterion being met. Trigger selection logic 52 can also be configured to determine a trigger for only one of the inputs, depending on the operating mode of PPC 22.

[0059] exist Figure 3 In this embodiment, the triggering criterion can be considered to include a wind speed component. That is, the trigger selection logic 52 also receives the measured wind speed as input. The measured wind speed is compared with a threshold wind speed. The trigger selection logic 52 uses this comparison as part of the triggering criterion and is configured to generate a trigger signal based on the triggering criterion only if the measured wind speed exceeds the threshold. In other words, the triggering criterion includes both a wind speed check and a trigger parameter. The trigger parameter can be compared with the threshold to determine whether the criterion is met, but a trigger signal is only sent to the boost controller 54 if the wind speed is above a certain level. Therefore, the wind speed check serves as a flag indicating whether a trigger signal can be generated. By performing both checks, it can be ensured that the boost controller 54 does not unnecessarily allow an increase in active power when there is insufficient wind speed.

[0060] In other embodiments, the triggering criteria may include only a wind speed check, or a combination of multiple different triggering parameters. In the above embodiments, the triggering criteria are issued for the entire WPP 12, but in other embodiments, the trigger may be specific to a subset of WTG 14.

[0061] If the triggering criteria are met, trigger selection logic 52 generates a trigger signal that is transmitted to boost controller 54. Boost controller 54 is configured to implement an active power boosting mode for a predetermined time period in response to receiving the trigger signal. In active power boosting mode, boost controller 54 provides a maximum active power value to limit selection logic 56 for each WTG, which sends these maximum active power values ​​to distributor 46 if no overlay limit is received from limit controller 58.

[0062] like Figure 3 As shown, the boost controller 54 includes a first timer 60 and a second timer 62. The first timer 60 is configured to run during a first portion of a predetermined time period, and the second timer 62 is configured to run during a second portion of the predetermined time period. The second portion is consecutive to the first portion, as will be described below.

[0063] The booster controller 54 activates the first timer 60 in response to receiving a trigger signal. Once the first portion of a predetermined time period has elapsed, the first timer 60 deactivates. The second timer 62 activates after the first portion, making the second portion continuous with the first. Therefore, the first timer 60 is activated and runs for a period of time in response to the trigger signal, then deactivates while the second timer 62 is activated and runs for another period of time. Once the second portion has elapsed, the second timer 62 also deactivates.

[0064] At the beginning of each section, that is, when each timer is activated, the maximum active power value is set. This value is fixed throughout its corresponding section. Therefore, the activation of the timer also activates a flag or indicator that the maximum active power value will be set to a predetermined level and prevented from being changed.

[0065] Since each timer has a fixed output value, the boost controller 54 is configured to ignore further triggers during a predetermined time period of timer operation. This means that further trigger signals may be received, or the trigger criteria may not be met during the predetermined time period, but this is not acknowledged by the boost controller 54. Instead, during the predetermined time period, and therefore when the timer is active, the boost controller 54 does not respond to external inputs related to triggering. This is useful when the trigger signal includes a flag with a value of 1 when the trigger criteria are met and a value of 0 when the trigger criteria are not met. If the boost controller 54 receives a signal indicating that the trigger criteria are met (i.e., the flag value is 1), it enters boost mode. Thereafter, changes in the value associated with the flag do not affect the operation of the boost controller 54 during the predetermined time period.

[0066] Two timers 60 and 62 are provided to allow different maximum active power levels to be transmitted to the distributor 46. When the first timer 60 is active, the maximum active power value is fixed at a boost level by the boost controller 54. The boost level is an active power value higher than the original rated or nominal power of each WTG 14. That is, it allows the distributor 46 to generate a higher setpoint for each WTG 14 than usual. Typically, the rated or nominal power of the WTG 14 is set at a level that the WTG can achieve over a wide range of wind speeds, so at higher wind speeds, the active power that the WTG 14 can generate is less than theoretically possible. Therefore, the capacity of the WTG 14 can be considered reduced to its rated power. The boost level utilizes this effective reduction by allowing the WTG 14 to generate power in a range above its rated power in order to provide an increase in active power from the WPP 12. An exemplary boost level is an active power increase of 10% above the rated power, such as 2.2MW for a 2MW WTG.

[0067] The boost level described here is over-rating and should not be confused with the so-called "super-boost" of WTG 14. Super-boost is the practice of providing a brief burst of active power by consuming the rotor's kinetic energy and reusing it as electrical energy, requiring a period of recovery during which the kinetic energy is regained. In contrast, the boost described here is sustainable because it can be maintained and extended by WTG 14 without requiring the recovery of kinetic energy.

[0068] However, sustained boosting does increase the load experienced by the turbine. A first timer prevents potentially disruptive practices of switching maximum values ​​between the boost level and the nominal level, where the maximum active power is fixed during a portion of the first timer's duration. A second timer 62 is provided to prevent repeated triggering immediately after a boost.

[0069] The second timer 62 is activated at the end of the first part and runs during the second part of the predetermined time period. During the second part, the maximum active power is set to the original rated active power of WTG 14, and therefore the maximum active power is reduced from the level set during the first part. Similar to the first timer 60, when the second timer 62 is running, the trigger is ignored and the maximum active power value is fixed.

[0070] Typically, the first timer 60 is used to limit the amount of time during which active power can be increased, while the second timer 62 is used to limit the amount of time during which active power cannot be increased.

[0071] After the second portion of the time period, the second timer 62 is deactivated, while the maximum active power value remains at its rated value. At this point, the boost controller can stop transmitting the maximum active power value to the selection logic 56, and the distributor 46 can determine the maximum active power value using only the nominal power supplied to it. In this embodiment, the time period includes a first portion and a second portion, such that at the end of the second portion, the active power boost mode is no longer active at the power plant controller.

[0072] At the end of the predetermined time period, once the second timer 62 has run and deactivated, the trigger signal is no longer ignored. The boost controller 54 checks to determine if a trigger signal was received at the end of the predetermined time period or recently. If so, it re-enters the active power boost mode and restarts the process. Otherwise, the nominal or rated power is used by the distributor 46 as the maximum active power value.

[0073] The running time of the first timer 60 and the second timer 62, i.e. the length of the first and second parts of the predetermined time period, can be changed depending on the desired result.

[0074] For example, in embodiments envisioned for WTG 14 to participate in the ancillary services market, the runtime of the first timer 60 is at least the duration of the minimum ancillary service for which WTG 14 is to participate. In some ancillary services, the duration of the first portion and the first timer 60 may be at least 6 seconds or at least 5 minutes. In some examples, the duration of the first timer and the first portion may be between 6 seconds and 5 minutes; in other examples, the length of the first timer may exceed 5 minutes. In some examples, the first timer may be within a 60-minute interval or an even longer interval. The second timer is set to avoid immediate, continuous triggering of higher maximum active power values ​​and is therefore likely to be relatively shorter compared to the first timer. In some examples, the length of the second timer 62 is less than or the same as the length of the first timer 60. In some examples, the length of the second timer 62, and therefore the length of the second portion, is at least 6 seconds; in other examples, it is 10 seconds. In other embodiments, the second timer may be set to provide over a longer period, such as between 5 and 60 minutes. In some examples implementing frequency support, the second timer 62 may be set to 0 seconds, allowing the first timer 60 to be retried very quickly and provide continuous frequency support. In this embodiment, the control module in the limit generation unit 50 may temporarily set the second timer to a length of 0 in order to allow this frequency support.

[0075] In other examples, the two timers can be set to minimize mechanical load. For instance, the number of times the hoist is turned on and off should be calculated based on the predicted wear of the WTG during hoisting and its expected lifespan relative to the WTG.

[0076] In another example, the first timer is set to include a period of at least 3 seconds to allow the WTG to reach a steady state. The duration of the timer can be set to avoid the resonant frequency range of the mechanical components within the WTG. This range is typically between 0.2 Hz and 5 Hz, so it is best to avoid setting the timer duration in the range of 0.2 s to 5 s.

[0077] Figure 4 This illustrates the relationship between the timer and active power. From Figure 4 As can be seen, a trigger signal is received at time T0. The trigger signal activates the active power boost mode and accordingly activates the first timer 60. In other words, the state of the first timer can change from "off" or a value of 0 to "on" or a value of 1. The first timer 60 operates during the first part of this time period (i.e., between the trigger time T0 and the end of the first part T1). Between T0 and T1, that is, while the first timer 60 is active, the maximum active power value is fixed at the boost level. At time T1, the first timer 60 deactivates, returning to the "off" or 0 state, while the second timer 62 becomes active. During the second part of this time period (i.e., between times T1 and T2), the second timer is active. Between T1 and T2, that is, while the second timer is active, the maximum active power value is fixed at the original nominal level. The predetermined time period is between times T0 and T2. Between times T0 and T2, the trigger signal is ignored. At time T2, the second timer 62 is inactive, and the boost controller 54 checks for a new trigger signal. If another trigger signal is received, the active power boost mode restarts. In this embodiment, at T2, another trigger signal is received, and the maximum active power value increases again and is fixed at the boost level, while the first timer is active.

[0078] although Figure 4 The diagram illustrates the variation between the nominal value of active power and the boost level, but in some embodiments, a ramp rate can be implemented. Implementing a ramp rate smooths the transition between different maximum active power values. The benefit of including a ramp rate is that it reduces the likelihood of overshoot or undershoot (which could be considered disturbance) on the power plant's active power curve due to slow allocation adjustments. In some examples, a maximum ramp rate can be set to prevent power levels from changing too rapidly, thereby reducing overshoot or undershoot.

[0079] The limit generation unit and active power controller for controlling the operation of WTG 14 can be described as method 100, an example of which is shown in Figure 5 As shown in the image.

[0080] from Figure 5As can be seen, method 100 begins at step 102 upon receiving a trigger signal indicating that the triggering criteria are met. As described above, the trigger signal can be received from trigger selection logic. The triggering criteria can be based on frequency level or electricity price. The triggering criteria may include a check of available power based on the wind speed measured at the generator or at the terminal. The available power without boost can be compared with the desired or preferred power level of the power plant, and the triggering criteria are met if the preferred power is greater than the available power. In some examples, the triggering criteria may include a direct wind speed check, where the measured wind speed is compared with a threshold, and a trigger signal is generated if the wind speed exceeds the threshold.

[0081] At the next step 104, an active power boosting mode is implemented. The active power boosting mode is implemented over a predetermined time period, which begins in response to the receipt of a trigger signal. As shown, the boosting mode includes steps 106 and 108, namely ignoring further trigger signals and generating one or more active power limits for each of one or more WTGs 14. Although ignoring the trigger signal 106 is described herein as an active step, it can be a passive action or a result of the mode's implementation.

[0082] At least during the first portion of a predetermined time period in which the active power enhancement mode is implemented, the active power limit is fixed at an active power enhancement level greater than the nominal active power level of WTG 14. This can be achieved by using one or more timers to measure those portions of the predetermined time period as described above, such that the active power enhancement level is fixed when the timer is active during the first portion, as shown in step 110. As an optional step, the method may include step 112, whereby during the second portion, the limit is fixed at the original nominal level. This step is optional because the first timer can exist alone, or the second timer can be set to zero seconds.

[0083] Although a single boost level and active power limit have been described above, it should be understood that multiple boost levels and active power limits may be used depending on the conditions. For example, a trigger signal may indicate a specific trigger criterion corresponding to a specific set of limits. Alternatively, more than one boost level may be set during the time period, such that the active power level is fixed at more than one boost level during that time period. It may be feasible to move between multiple boost levels and limits during the first part of the period, such that fixing the active power level at one level means fixing the active power level above the lowest boost level.

[0084] It should be understood that various changes and modifications can be made to this invention without departing from the scope of this application.

Claims

1. A method (100) for controlling one or more wind turbine generators (14), the method (100) comprising: Receive the first trigger signal indicating that the trigger criteria are met; In response to receiving a first trigger signal, the one or more wind turbine generators are operated in an active power boost mode for a predetermined time period, wherein operating the one or more wind turbine generators in the active power boost mode includes: In active power enhancement mode, a second trigger signal is received based on changes in the trigger standard; Ignore the second trigger signal; and One or more active power limits are set for each of the one or more wind turbine generators (14), wherein, at least during a first part of the predetermined time period, the one or more active power limits are fixed at an active power boost level that is greater than the nominal active power level of the one or more wind turbine generators (14).

2. The method (100) according to claim 1, wherein, During the first part, the one or more active power limits are fixed through the following steps: Activate the first timer (60) and continue the first portion of the predetermined time period; The upper limit of active power is set as the level of active power enhancement; as well as When the first timer (60) is active, the upper limit of active power is prevented from being changed.

3. The method (100) according to claim 1 or 2, wherein, During a second portion of the predetermined time period that is consecutive to the first portion of the predetermined time period, the one or more active power limits are fixed at the nominal active power level of the one or more wind turbine generators (14).

4. The method (100) according to claim 3, wherein, During the second part, the one or more active power limits are fixed through the following steps: Activate the second timer (62) and continue the second portion of the predetermined time period; The upper limit of active power is set to the nominal active power level; as well as When the second timer (62) is active, the upper limit of active power is prevented from being changed.

5. The method (100) according to claim 3, wherein, The length of the first part is greater than the length of the second part.

6. The method (100) according to claim 3, wherein, The predetermined time period consists of the first part and the second part.

7. The method (100) according to claim 1 or 2, wherein, The method includes the following steps at the end of the predetermined time period: Check the trigger criteria; and at least one of the following: If the triggering criteria are still met, then re-enter the active power enhancement mode; or If the triggering criteria are not met, the active power limit of the one or more wind turbine generators (14) is set to the nominal active power level of the one or more wind turbine generators (14), and a new triggering signal is awaited.

8. The method (100) according to claim 1 or 2, wherein, The triggering criteria are based on one or more of the measured grid frequency and electricity price.

9. The method (100) according to claim 1 or 2, wherein, The triggering criterion is based on the measured wind speed level.

10. The method (100) according to claim 1 or 2, wherein, The triggering criteria include the generator’s expected active power level exceeding the active power output that the generator can supply at its nominal rated power, wherein the active power output is based on the measured wind speed for each generator.

11. The method (100) according to claim 1 or 2, wherein, The active power enhancement level includes the level of active power that each wind turbine generator (14) can supply without consuming the kinetic energy stored in the transmission system of the generator.

12. The method (100) according to claim 1 or 2, wherein, During the active power boosting mode, a ramp rate is applied during the transition period between active power limits.

13. A power plant controller (22) including a limit generation unit (50) configured to perform the method (100) according to any one of claims 1 to 12.

14. The power plant controller (22) according to claim 13, wherein, The limit generation unit (50) includes a first timer (60) and a second timer (62).

15. The power plant controller (22) according to claim 13 or 14, wherein, The power plant controller includes a distributor (46), wherein the limit generation unit (50) is configured to send generated active power limits to the distributor (46), and the distributor (46) is configured to: Receive active power reference from the power station (12) including the plurality of wind turbine generators (14); Determine the active power setpoint of the wind turbine generator (14); The generated active power limit is applied to the active power setpoint of each generator to achieve a restricted active power setpoint. as well as Each restricted active power setpoint is assigned to its corresponding wind turbine generator (14) for controlling the active power output of the wind turbine generator (14).

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