A power adjustment method, apparatus and electronic device

Abstract

The application provides a power adjustment method and device and electronic equipment, wherein after determining that a preset fault occurs in a power grid, if the power loss of new energy is greater than the current power shortage of the power grid, that is, the new energy unit enters a low-pass control mode to reduce active power output, the active power of the new energy unit is adjusted according to a preset power adjustment strategy, or the active power of the new energy unit is adjusted according to a preset power adjustment strategy and the active power recovery slope of the new energy unit is adjusted in different time periods, so that the active power output by the new energy unit is increased in the manner of adjusting the active power of the new energy unit, thereby avoiding the problem of low frequency of the power grid caused by the loss of a large amount of active power.

Description

Technical Field

[0001] This invention relates to the field of power regulation, and more specifically, to a power regulation method, apparatus, and electronic device. Background Technology

[0002] In recent years, the installed capacity of new energy in regions rich in new energy resources, such as Northwest, North, and Northeast China, has grown rapidly, forming several new energy bases with a capacity of tens of millions of kilowatts. In response to the national policy of concentrated development of new energy resources, several large-capacity ultra-high voltage direct current (UHVDC) and supporting new energy base transmission projects have been put into operation. UHVDC transmission lines generally lack supporting conventional generating units and have weak electrical connections with the main grid, exhibiting the characteristics of "large DC capacity, large new energy capacity, and weak AC capacity," and weak frequency / voltage regulation capabilities in the DC near-field region.

[0003] Currently, in order to achieve stable operation without disconnecting from the grid and actively support the grid during grid faults, new energy generating units must have a fault low voltage ride-through control function. This function automatically switches between steady-state control mode and low voltage ride-through control mode based on the degree of voltage drop at the generator terminals (0.85pu~0.9pu).

[0004] For grids with a high proportion of renewable energy, after a severe AC / DC fault at the sending and receiving ends, the grid voltage drops, which in turn causes the voltage at the renewable energy grid-connected generator terminals to drop. The renewable energy units then enter the low-frequency control mode, reducing the output active power and causing the grid to lose a large amount of active power, thus triggering low-frequency grid activity. Summary of the Invention

[0005] In view of this, the present invention provides a power regulation method, device and electronic equipment to solve the problem that after a serious AC / DC fault at the sending and receiving ends, the new energy generating units enter the low-frequency control mode, the output active power is reduced, and the power grid loses a large amount of active power, thereby causing the power grid to be low-frequency.

[0006] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0007] A power regulation method, comprising:

[0008] After determining that a preset fault has occurred in the power grid, the current power deficit of the power grid and the power loss of new energy sources are determined; the power loss of new energy sources is the sum of the power loss of new energy sources disconnecting from the grid and the temporary power loss due to low voltage penetration.

[0009] If the power loss of the new energy source is greater than the current power deficit of the power grid, determine whether the temporary power loss due to low-voltage transmission is not greater than the current power deficit of the power grid.

[0010] If so, the active power of the new energy unit will be adjusted according to the preset power adjustment strategy;

[0011] If not, the active power of the new energy unit is adjusted according to the preset power adjustment strategy, and the active power recovery slope of the new energy unit is adjusted in different time periods to adjust the active power of the new energy unit.

[0012] Optionally, determining the current power deficit in the power grid includes:

[0013] The current power deficit is obtained from the online power grid system. The current power deficit is the power deficit determined by the online power grid system when the power grid transient minimum frequency drops to a specified frequency, based on the power grid power response curve obtained from the simulation of the current real-time operation status of the power grid.

[0014] Optionally, the power loss of the new energy source is determined, including:

[0015] Obtain the operating data of the new energy units, and calculate the power loss due to grid disconnection and the temporary power loss due to low-voltage operation based on the operating data;

[0016] The sum of the power loss due to grid disconnection of the new energy source and the power loss due to temporary low-voltage transmission is taken as the power loss of the new energy source.

[0017] Optionally, the active power of the new energy generating unit is adjusted according to a preset power regulation strategy, including:

[0018] The adjustable capacity of energy storage and the DC regulation power are obtained, and based on the adjustable capacity of energy storage and the DC regulation power, the active power of the new energy unit is adjusted by adopting the DC regulation strategy and / or the emergency power strategy of energy storage.

[0019] Optionally, adjusting the active power recovery slope of the new energy unit in different time periods includes:

[0020] Obtain the target time required for the power grid's transient minimum power to drop to a specified power;

[0021] The target time is divided into multiple time intervals, and the active power recovery slope of the time intervals is calculated.

[0022] The active power recovery slope of the new energy unit is adjusted according to the active power recovery slope of the time interval.

[0023] Optionally, adjusting the active power recovery slope of the new energy unit according to the active power recovery slope of the time interval includes:

[0024] Within the first time interval, the active power recovery slope of the new energy unit is controlled to be the active power recovery slope of the first time interval, or the active power recovery slope currently used by the new energy unit.

[0025] At the starting time point of the second or subsequent time interval, obtain the power grid frequency and the frequency threshold of the time interval;

[0026] When the grid frequency is not less than the frequency threshold of the time interval, the new energy unit is controlled to continue to adjust the active power according to the active power recovery slope of the currently used active power.

[0027] Optionally, if the power grid frequency is less than the frequency threshold of the time interval, the method further includes:

[0028] Determine whether the active power recovery slope currently used by the new energy unit is not less than the active power recovery slope of the time interval;

[0029] If so, the new energy unit is controlled to continue adjusting its active power according to the recovery slope of the currently used active power.

[0030] If not, the new energy unit is controlled to adjust its active power according to the active power recovery slope of the time interval.

[0031] Optionally, obtaining the frequency threshold of the time interval includes:

[0032] The frequency of the start time point of the time interval determined from the power grid response curve is obtained and used as the frequency threshold of the time interval.

[0033] A power regulation device, comprising:

[0034] The power determination module is used to determine the current power deficit of the power grid and the power loss of new energy sources after a preset fault is detected in the power grid; the power loss of new energy sources is the sum of the power loss of new energy sources disconnecting from the grid and the temporary power loss due to low voltage.

[0035] The power judgment module is used to determine whether the temporary power loss of low-voltage transmission is not greater than the current power deficit of the power grid when the power loss of the new energy source is greater than the current power deficit of the power grid.

[0036] The first adjustment module is used to adjust the active power of the new energy unit according to the preset power adjustment strategy if the condition is met.

[0037] The second adjustment module is used to adjust the active power of the new energy unit according to a preset power adjustment strategy if not, and to adjust the active power recovery slope of the new energy unit in different time periods to adjust the active power of the new energy unit.

[0038] An electronic device includes: a memory and a processor;

[0039] The memory is used to store programs;

[0040] The processor calls the program and executes the power regulation method described above.

[0041] Compared with the prior art, the present invention has the following beneficial effects:

[0042] This invention provides a power regulation method, device, and electronic equipment. After determining that a preset fault has occurred in the power grid, when the power loss of new energy sources exceeds the current power deficit of the power grid (i.e., when the new energy generating units enter low-voltage control mode to reduce active power output), the active power of the new energy generating units is adjusted according to a preset power regulation strategy, or the active power of the new energy generating units is adjusted according to a preset power regulation strategy, and the active power recovery slope of the new energy generating units is adjusted in different time periods. In order to adjust the active power of the new energy generating units, the active power output of the new energy generating units is increased, thereby avoiding the problem of low frequency in the power grid caused by the loss of a large amount of active power. Attached Figure Description

[0043] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0044] Figure 1 This invention provides active power response curves for different renewable energy converters during low-voltage ride-through and low-voltage recovery periods, as an embodiment of the invention.

[0045] Figure 2 A flowchart of a power regulation method provided in an embodiment of the present invention;

[0046] Figure 3 This invention provides a power grid power response curve when the power grid's transient minimum frequency drops to a specified frequency.

[0047] Figure 4 A flowchart illustrating a method for adjusting the active power recovery slope of a new energy generating unit in different time periods, as provided in an embodiment of the present invention;

[0048] Figure 5 A curve showing the active power recovery slope during low-voltage operation of a new energy source, provided as an embodiment of the present invention;

[0049] Figure 6 This is a schematic diagram of a power regulation device provided in an embodiment of the present invention. Detailed Implementation

[0050] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0051] In recent years, the installed capacity of new energy in regions rich in new energy resources, such as Northwest, North, and Northeast China, has grown rapidly, forming several new energy bases with a capacity of tens of millions of kilowatts. In response to the national policy of concentrated development of new energy resources, several large-capacity ultra-high voltage direct current (UHVDC) and supporting new energy base transmission projects have been put into operation. UHVDC transmission lines generally lack supporting conventional generating units and have weak electrical connections with the main grid, exhibiting the characteristics of "large DC capacity, large new energy capacity, and weak AC capacity," and weak frequency / voltage regulation capabilities in the DC near-field region.

[0052] Currently, in order to achieve stable grid connection and proactive grid support during grid faults, new energy generating units must possess low-voltage ride-through (LVRT) control functionality. This involves automatically switching between steady-state and LVRT control modes based on the voltage drop at the generator terminals (0.85 pu to 0.9 pu). However, the behavioral requirements for power electronic equipment during LVRT in new energy units are not yet clearly defined, leading to significant differences in transient characteristics between different manufacturers and models of power electronic equipment. Figure 1 During the low-voltage period: most converters directly reduce active power to below 20% of steady-state active power or even stop generating active power altogether. During the low-voltage recovery period: most converters restore active power at different slopes, resulting in a recovery time of 0.3s to 1.8s to 90% of the active power before the fault.

[0053] For power grids with a high proportion of renewable energy, severe AC / DC faults at both the sending and receiving ends (such as weak voltage regulation capabilities at the sending end of UHVDC and its supporting renewable energy centralized transmission lines, low short-circuit capacity of the near-field system, DC commutation failure, or severe AC faults in the near-field) cause a drop in grid voltage, which in turn leads to a drop in the voltage at the renewable energy grid-connected generator terminals. This causes the renewable energy units to enter low-frequency protection mode, reducing their output active power and resulting in a significant loss of active power in the grid, thus triggering low-frequency activity. If the short-term power loss is too large and the recovery time is not timely, it may lead to low-frequency activity in the sending-end system, triggering the third line of defense or the low-frequency protection settings of the renewable energy units, causing a disorderly chain reaction. As the proportion of renewable energy installed capacity in the sending-end grid gradually increases, the system's frequency regulation capability further decreases. The larger the capacity of the DC operation, the more renewable energy installed capacity in the near-field, and the more renewable energy units enter low-frequency protection mode after severe AC / DC faults, the greater the temporary active power loss in the grid, and the more prominent the aforementioned problems become.

[0054] In response to the problem of low-frequency grids caused by severe AC / DC faults at the sending and receiving ends of high-proportion renewable energy power grids, a large number of renewable energy sources enter the low-voltage ride-through phase, resulting in a temporary loss of a large amount of active power in the grid. This invention proposes a renewable energy active power recovery parameter switching technology based on real-time online simulation curve comparison. According to the grid frequency recovery situation, the active power recovery slope of renewable energy units is dynamically switched to accelerate system frequency recovery and reduce the risk of grid low frequency.

[0055] Specifically, this invention provides a power regulation method, device, and electronic device. After determining that a preset fault has occurred in the power grid, when the power loss of new energy sources exceeds the current power deficit of the power grid (i.e., when the new energy generating units enter low-voltage control mode to reduce active power output), the active power of the new energy generating units will be adjusted according to a preset power regulation strategy, or the active power of the new energy generating units will be adjusted according to a preset power regulation strategy, and the active power recovery slope of the new energy generating units will be adjusted in different time periods. In order to adjust the active power of the new energy generating units, the active power output of the new energy generating units will be increased, thereby avoiding the problem of low frequency in the power grid caused by the loss of a large amount of active power.

[0056] Based on the above, this invention provides a power regulation method. The main body executing this power regulation method is the controller in the new energy low-voltage emergency frequency control master station.

[0057] Reference Figure 2 A power regulation method may include:

[0058] S11. After determining that a preset fault has occurred in the power grid, determine the current power deficit of the power grid and the power loss of new energy sources.

[0059] The power loss of the new energy source is the sum of the power loss due to grid disconnection and the temporary power loss due to low-voltage transmission.

[0060] In practical applications, based on the power grid operation mode, the online power grid system acquires the current real-time operating status of the power grid every 5-10 minutes (time is configurable). Online time-domain simulation is then performed on the current real-time operating status to simulate the power grid frequency response curve under high power deficit conditions, such as... Figure 3 As shown, the simulation curve f(t) is obtained when the power grid's transient minimum frequency just drops to a specified frequency, such as the first round of low-frequency load shedding in the three-line defense (f0, with a set value of 49.25Hz for the first round of the special round). Simultaneously, the current power grid power deficit ΔP0 and the target time t required for the power grid's transient minimum frequency to drop to the specified frequency are recorded. s And it is sent to the controller in the emergency frequency control master station for new energy low-voltage transmission.

[0061] In this embodiment, the power grid frequency response curve is used to determine the current power grid deficit ΔP0, which can advance the power adjustment time. Before the problem of a severe drop in power grid frequency occurs, the simulation can predict the possibility of a severe drop in power grid frequency, rather than adjusting after the problem occurs. This can improve the response processing speed and prevent the occurrence of severe low frequency problems in the power grid in a timely manner.

[0062] In other words, determining the current power deficit in the power grid includes:

[0063] The current power deficit is obtained from the online power grid system. The current power deficit is the power deficit determined by the online power grid system when the power grid transient minimum frequency drops to a specified frequency, based on the power grid power response curve obtained from the simulation of the current real-time operation status of the power grid.

[0064] After receiving the grid frequency response curve under the current grid power deficit ΔP0, the controller in the new energy low-voltage emergency frequency control master station synchronously acquires frequency values ​​at multiple times, such as... The frequency value f1 corresponding to the time. The frequency value f2 corresponding to the time.

[0065] The controller in the new energy low-voltage emergency frequency control master station detects grid faults in real time and monitors the operating status and operating power of new energy units. When the controller equipped with the frequency emergency control system detects a preset fault in the grid after the grid has a pre-selected fault set {Xi} (the fault set refers to the set of faults that need attention determined by the operation dispatcher based on guidelines and experience), it collects the operating data of the grid new energy units, such as low-voltage signals, grid disconnection signals, and operating power.

[0066] Then, based on the aforementioned operational data, the power loss due to grid disconnection of new energy sources and the temporary power loss due to low-voltage transmission are calculated.

[0067] In detail, based on operational data, the power loss ΔP due to grid disconnection of new energy sources is determined. y-损失 Low-level temporary power loss ΔP z-损失 Energy storage adjustable capacity ΔP 储-支撑 DC regulating power ΔP 直-支撑 Such as DC power increase or decrease.

[0068] Among them, the power loss ΔP due to grid disconnection of new energy sources y-损失 This refers to the loss of active power caused by the disconnection of new energy generating units from the grid after a power grid system failure. This loss of active power is permanent.

[0069] Low-level temporary power loss ΔP z-损失This is because the new energy generating unit reduces its own active power output as a self-protection mechanism. Once the grid voltage recovers and the new energy generating unit breaks through the low voltage, its output returns to the level before the fault. This loss of active power is temporary.

[0070] Power loss ΔP when new energy is disconnected from the grid y-损失 Low-level temporary power loss ΔP z-损失 The calculation formula is:

[0071]

[0072]

[0073] Where: n is the number of off-grid renewable energy units, P i-脱网 P is the operating power of a single renewable energy unit before it is disconnected from the grid. m is the number of renewable energy units that have entered the low-voltage circuit. j-低穿-前 -P j-低穿-后 It is the operating power loss of a single low-voltage new energy unit, where i and j are variables, with i ranging from 1 to n and j ranging from 1 to m.

[0074] Then, the sum of the power loss due to grid disconnection of the new energy source and the power loss due to temporary low-voltage transmission is taken as the power loss of the new energy source.

[0075] That is, the power loss of new energy sources = ΔP y-损失 +ΔP z-损失 .

[0076] S12. Determine whether the power loss of new energy sources is greater than the current power deficit of the power grid; if so, proceed to step S13.

[0077] Specifically, if the power loss from new energy sources exceeds the current power deficit in the power grid ΔP0, i.e. ΔP y-损失 +ΔP z-损失 >ΔP0 indicates that the minimum transient frequency of the power grid has dropped to the specified frequency, which meets the emergency frequency control requirements for low-voltage power transmission of new energy sources, and an emergency power regulation operation is required.

[0078] If the power loss from new energy sources is no greater than the current power deficit in the power grid ΔP0, i.e. ΔP y-损失 +ΔP z-损失 If ≤ΔP0, it means that the minimum transient frequency of the power grid has not dropped to the specified frequency, which satisfies the requirement to exit the emergency frequency control for low-voltage transmission of new energy sources. No power regulation operation will be performed, and the process will return to step S11.

[0079] S13. Determine whether the temporary power loss due to low-voltage transmission is not greater than the current power deficit of the power grid; if yes, proceed to step S14; if no, proceed to step S15.

[0080] Specifically, based on the judgment result that the temporary power loss during low-voltage testing is not greater than the current power deficit of the power grid, different power regulation strategies are adopted for power regulation.

[0081] S14. Adjust the active power of the new energy unit according to the preset power adjustment strategy.

[0082] Specifically, if the temporary power loss due to low-voltage transmission is not greater than the current power deficit in the grid, i.e., ΔP z-损失 If the value is ≤ΔP0, it indicates that the active power loss is relatively small, and power regulation can be achieved by using DC regulation strategies (such as DC sag-off strategies) or emergency power storage strategies. At this point, the adjustable energy storage capacity ΔP is obtained. 储-支撑 and DC regulation power ΔP 直-支撑 And based on the energy storage adjustable capacity ΔP 储-支撑 and the DC regulation power ΔP 直-支撑 The active power of the new energy generating units is adjusted by adopting DC regulation strategies and / or energy storage emergency power strategies.

[0083] In specific adjustments, the DC regulation strategy and / or the energy storage emergency power strategy support a theoretical power of ΔP. 支撑(理论) =ΔP y-损失 +ΔP z-损失 -ΔP0, if ΔP 支撑(理论) ≥ΔP 储-支撑 +ΔP 直-支撑 The controller in the emergency frequency control master station for new energy low-voltage transmission issues control support for the actual power ΔP. 支撑(实际) =ΔP 储-支撑 +ΔP 直-支撑 .

[0084] If the DC regulation strategy or the energy storage emergency power strategy is unavailable, then when the DC regulation strategy is unavailable, ΔP 支撑(实际) =ΔP 储-支撑 If the emergency power strategy for energy storage is unavailable, ΔP 支撑(实际) =ΔP 直-支撑 .

[0085] S15. Adjust the active power of the new energy generator unit according to the preset power adjustment strategy, and adjust the active power recovery slope of the new energy generator unit in different time periods to adjust the active power of the new energy generator unit.

[0086] Specifically, if ΔP z-损失 A value greater than ΔP0 indicates that the temporary power deficit in the grid caused by low-frequency load shedding from renewable energy sources exceeds the maximum grid deficit, i.e., the current grid power deficit ΔP0 may trigger low-frequency load shedding, requiring control measures. The first step is to employ DC regulation strategies (such as DC sag / rapid-rise strategies) or emergency power storage strategies to support ΔP0. y-损失To balance the power deficit caused by the disconnection of new energy units from the grid.

[0087] In practical applications, the temporary disconnection of active power caused by the low-voltage transmission of renewable energy is not a permanent loss. After the low-voltage transmission is restored, the active power of the renewable energy unit will be restored. This part of the active power is only temporarily lost. However, if the temporary loss lasts too long, it may trigger low-frequency load shedding actions at a high frequency. Therefore, this invention accelerates the active power recovery rate during the low-voltage transmission of renewable energy through coordinated control, thereby reducing the risk of low-frequency load shedding actions.

[0088] In addition to adjusting the active power of the new energy generator according to the preset power adjustment strategy, the present invention will also adjust the active power recovery slope of the new energy generator in different time periods to adjust the active power of the new energy generator.

[0089] Specifically, refer to Figure 4 Adjusting the active power recovery slope of the new energy unit in different time periods may include:

[0090] S21. Obtain the target time required for the power grid's transient minimum power to drop to the specified power.

[0091] Specifically, the target time is t as mentioned above. s .

[0092] S22. Divide the target time into multiple time intervals and calculate the active power recovery slope of the time intervals.

[0093] In practical applications, taking into account the inherent mechanical properties of new energy sources, the target time can be divided into three equal time intervals, namely...

[0094] Reference Figure 5 t0 is the origin of the coordinate axis, which can generally be 0.

[0095] For each time interval, a corresponding active power recovery slope K will be configured. Pi The value of i ranges from 0 to 2, where the power recovery slope of the first time interval is... Power recovery slope in the second time interval The power recovery slope K in the third time interval P2 =∞.

[0096] S23. Adjust the active power recovery slope of the new energy unit according to the active power recovery slope of the time interval.

[0097] Specifically, within the first time interval, the active power recovery slope of the new energy unit is controlled to be the active power recovery slope of the first time interval, or the active power recovery slope currently used by the new energy unit.

[0098] In detail, the controller in the emergency frequency control master station for new energy low-voltage transmission determines ΔP. y-损失 +ΔP z-损失 >ΔP0 and ΔP z-损失 After ΔP0, an instruction is issued to all renewable energy units that have entered the low-temperature recovery phase. The active power recovery slope during the first time interval of the renewable energy low-temperature recovery period is the active power recovery slope K of the first time interval. Pi =K P0 If the active power recovery slope of the current new energy unit is ≥ K P0 Then the recovery slope of the active power currently used by the new energy units will remain unchanged.

[0099] At the starting time point of the second or subsequent time interval, obtain the power grid frequency and the frequency threshold of the time interval.

[0100] Specifically, obtaining the frequency threshold of the time interval means: obtaining the frequency of the start time point of the time interval determined from the power grid response curve, and using it as the frequency threshold of the time interval.

[0101] When the grid frequency is not less than the frequency threshold of the time interval, the new energy unit is controlled to continue to adjust the active power according to the active power recovery slope of the currently used active power.

[0102] In practical applications, The grid frequency f0 is constantly collected. If f0 ≥ f1, the current active power recovery slope is maintained until all the power of the new energy generating units entering the low-voltage circuit is restored. If f0 ≥ f1 is not satisfied, it is determined whether the current active power recovery slope of the new energy generating units is not less than the active power recovery slope of the time interval. If yes, the active power of the new energy generating units is controlled to continue to adjust according to the current active power recovery slope. If no, the active power of the new energy generating units is controlled to adjust according to the active power recovery slope of the time interval.

[0103] Specifically, during the recovery period of new energy power generation, in the second time interval, the active power recovery slope of the new energy units is adjusted by the active power recovery slope of the second time interval, which is related to the active power K. Pi =K P1 If the active power recovery slope of the current new energy unit is ≥ K P1 Then the recovery slope of the active power currently used by the new energy units will remain unchanged.

[0104] exist The grid frequency f0 is constantly collected. If f0 ≥ f2, the current active power recovery slope is maintained until all power from the low-voltage renewable energy units recovers. If f0 ≥ f2 is not satisfied, in the third time interval, the active power recovery slope of the renewable energy units is adjusted to the active power K based on the active power recovery slope of the third time interval. Pi =K P2 If the active power recovery slope of the current new energy unit is ≥ K P2 Then the recovery slope of the active power currently used by the new energy units remains unchanged until all the power of the new energy units entering the low-voltage circuit is restored, and the new energy low-voltage emergency frequency control is exited.

[0105] In this embodiment, after a preset fault is determined in the power grid, when the power loss of new energy sources exceeds the current power deficit of the power grid, i.e. when the new energy generating units enter the low-voltage control mode to reduce active power output, the active power of the new energy generating units will be adjusted according to a preset power adjustment strategy, or the active power of the new energy generating units will be adjusted according to a preset power adjustment strategy, and the active power recovery slope of the new energy generating units will be adjusted in different time periods. In order to adjust the active power of the new energy generating units, the active power output of the new energy generating units will be increased, thereby avoiding the problem of low frequency in the power grid caused by the loss of a large amount of active power.

[0106] In addition, in view of the lack of effective control measures for the transient low frequency problem caused by the temporary drop in active power during the low-frequency ride of new energy sources in the existing power grid, the present invention dynamically switches the active power recovery slope of new energy units according to the frequency recovery of the power grid, accelerates the system frequency recovery, reduces the risk of low frequency in the power grid, and can alleviate the problem of low frequency caused by the temporary power shortage in the system due to the low-frequency ride of new energy sources to a certain extent.

[0107] In addition, this invention can not only restore the active power of new energy sources as soon as possible to ensure the stability of the power grid frequency, but also take into account the inherent mechanical properties of new energy wind turbines, and accelerate the restoration of their own power from slow to fast.

[0108] Optionally, based on the embodiments of the power regulation method described above, another embodiment of the present invention provides a power regulation device, referring to... Figure 6 It can include:

[0109] The power determination module 11 is used to determine the current power deficit of the power grid and the power loss of new energy sources after a preset fault is determined to occur in the power grid; the power loss of new energy sources is the sum of the power loss of new energy sources disconnecting from the grid and the temporary power loss of low-voltage transmission.

[0110] Power determination module 12 is used to determine whether the temporary power loss of low-voltage transmission is not greater than the current power deficit of the power grid when the power loss of the new energy source is greater than the current power deficit of the power grid.

[0111] The first adjustment module 13 is used to adjust the active power of the new energy unit according to the preset power adjustment strategy if the condition is met.

[0112] The second adjustment module 14 is used to adjust the active power of the new energy unit according to a preset power adjustment strategy if not, and to adjust the active power recovery slope of the new energy unit in different time periods to adjust the active power of the new energy unit.

[0113] Furthermore, when determining the current power deficit in the power grid, the power determination module 11 is specifically used for:

[0114] The current power deficit is obtained from the online power grid system. The current power deficit is the power deficit determined by the online power grid system when the power grid transient minimum frequency drops to a specified frequency, based on the power grid power response curve obtained from the simulation of the current real-time operation status of the power grid.

[0115] Furthermore, when determining the power loss of new energy sources, the power determination module 11 is specifically used for:

[0116] Obtain the operating data of the new energy units, and calculate the power loss due to grid disconnection and the temporary power loss due to low-voltage operation based on the operating data;

[0117] The sum of the power loss due to grid disconnection of the new energy source and the power loss due to temporary low-voltage transmission is taken as the power loss of the new energy source.

[0118] Furthermore, the first adjustment module 13 is specifically used for:

[0119] The adjustable capacity of energy storage and the DC regulation power are obtained, and based on the adjustable capacity of energy storage and the DC regulation power, the active power of the new energy unit is adjusted by adopting the DC regulation strategy and / or the emergency power strategy of energy storage.

[0120] Furthermore, the second adjustment module 14 includes:

[0121] The time acquisition submodule is used to obtain the target time required for the power grid's transient minimum power to drop to a specified power.

[0122] The slope calculation submodule is used to divide the target time into multiple time intervals and calculate the active power recovery slope of the time intervals.

[0123] The slope adjustment submodule is used to adjust the active power recovery slope of the new energy unit according to the active power recovery slope of the time interval.

[0124] Furthermore, the slope adjustment submodule includes:

[0125] The first adjustment unit is used to control the active power recovery slope of the new energy unit to be the active power recovery slope of the first time interval, or the active power recovery slope currently used by the new energy unit, within the first time interval.

[0126] The data acquisition unit is used to acquire the power grid frequency and the frequency threshold of the time interval at the starting time point in the second or subsequent time interval.

[0127] The second adjustment unit is used to control the new energy unit to continue adjusting the active power according to the current active power recovery slope when the grid frequency is not less than the frequency threshold of the time interval.

[0128] Furthermore, the slope adjustment submodule also includes a third adjustment unit, used for:

[0129] If the grid frequency is less than the frequency threshold of the time interval, determine whether the active power recovery slope currently used by the new energy unit is not less than the active power recovery slope of the time interval. If yes, control the new energy unit to continue adjusting the active power according to the active power recovery slope currently used. If no, control the new energy unit to adjust the active power according to the active power recovery slope of the time interval.

[0130] Furthermore, when the data acquisition unit is used to obtain the frequency threshold of a time interval, it is specifically used for:

[0131] The frequency of the start time point of the time interval determined from the power grid response curve is obtained and used as the frequency threshold of the time interval.

[0132] In this embodiment, after a preset fault is determined in the power grid, when the power loss of new energy sources exceeds the current power deficit of the power grid, i.e. when the new energy generating units enter the low-voltage control mode to reduce active power output, the active power of the new energy generating units will be adjusted according to a preset power adjustment strategy, or the active power of the new energy generating units will be adjusted according to a preset power adjustment strategy, and the active power recovery slope of the new energy generating units will be adjusted in different time periods. In order to adjust the active power of the new energy generating units, the active power output of the new energy generating units will be increased, thereby avoiding the problem of low frequency in the power grid caused by the loss of a large amount of active power.

[0133] It should be noted that the working process of each module, submodule and unit in this embodiment is described in the corresponding description in the above embodiment, and will not be repeated here.

[0134] Optionally, based on the embodiments of the power regulation method and apparatus described above, another embodiment of the present invention provides an electronic device, including: a memory and a processor;

[0135] The memory is used to store programs;

[0136] The processor calls the program and executes the power regulation method described above.

[0137] In this embodiment, after a preset fault is determined in the power grid, when the power loss of new energy sources exceeds the current power deficit of the power grid, i.e. when the new energy generating units enter the low-voltage control mode to reduce active power output, the active power of the new energy generating units will be adjusted according to a preset power adjustment strategy, or the active power of the new energy generating units will be adjusted according to a preset power adjustment strategy, and the active power recovery slope of the new energy generating units will be adjusted in different time periods. In order to adjust the active power of the new energy generating units, the active power output of the new energy generating units will be increased, thereby avoiding the problem of low frequency in the power grid caused by the loss of a large amount of active power.

[0138] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A power regulation method, characterized in that, include: After determining that a preset fault has occurred in the power grid, the current power deficit of the power grid and the power loss of new energy sources are determined; the power loss of new energy sources is the sum of the power loss of new energy sources disconnecting from the grid and the temporary power loss due to low voltage penetration. If the power loss of the new energy source is greater than the current power deficit of the power grid, determine whether the temporary power loss due to low-voltage transmission is not greater than the current power deficit of the power grid. If so, the active power of the new energy unit will be adjusted according to the preset power adjustment strategy; If not, the active power of the new energy unit is adjusted according to the preset power regulation strategy, and the active power recovery slope of the new energy unit is adjusted in different time periods to regulate the active power of the new energy unit; the preset power regulation strategy includes DC regulation strategy or energy storage emergency power strategy.

2. The power regulation method according to claim 1, characterized in that, Determine the current power deficit in the power grid, including: The current power deficit is obtained from the online power grid system. The current power deficit is the power deficit determined by the online power grid system when the power grid transient minimum frequency drops to a specified frequency, based on the power grid power response curve obtained from the simulation of the current real-time operation status of the power grid.

3. The power regulation method according to claim 1, characterized in that, Determine the power loss of new energy sources, including: Obtain the operating data of the new energy units, and calculate the power loss due to grid disconnection and the temporary power loss due to low-voltage operation based on the operating data; The sum of the power loss due to grid disconnection of the new energy source and the power loss due to temporary low-voltage transmission is taken as the power loss of the new energy source.

4. The power regulation method according to claim 1, characterized in that, Adjusting the active power of new energy generating units according to a preset power regulation strategy includes: The adjustable capacity of energy storage and the DC regulation power are obtained, and based on the adjustable capacity of energy storage and the DC regulation power, the active power of the new energy unit is adjusted by adopting the DC regulation strategy and / or the emergency power strategy of energy storage.

5. The power regulation method according to claim 1, characterized in that, Adjusting the active power recovery slope of the new energy generating units in different time periods includes: Obtain the target time required for the power grid's transient minimum power to drop to a specified power; The target time is divided into multiple time intervals, and the active power recovery slope of the time intervals is calculated. The active power recovery slope of the new energy unit is adjusted according to the active power recovery slope of the time interval.

6. The power regulation method according to claim 5, characterized in that, Adjusting the active power recovery slope of the new energy unit according to the active power recovery slope of the time interval includes: Within the first time interval, the active power recovery slope of the new energy unit is controlled to be the active power recovery slope of the first time interval, or the active power recovery slope currently used by the new energy unit. At the starting time point of the second or subsequent time interval, obtain the power grid frequency and the frequency threshold of the time interval; When the grid frequency is not less than the frequency threshold of the time interval, the new energy unit is controlled to continue to adjust the active power according to the active power recovery slope of the currently used active power.

7. The power regulation method according to claim 6, characterized in that, If the power grid frequency is less than the frequency threshold of the time interval, the method further includes: Determine whether the active power recovery slope currently used by the new energy unit is not less than the active power recovery slope of the time interval; If so, the new energy unit is controlled to continue adjusting its active power according to the recovery slope of the currently used active power. If not, the new energy unit is controlled to adjust its active power according to the active power recovery slope of the time interval.

8. The power regulation method according to claim 6, characterized in that, Obtaining the frequency threshold of the time interval includes: The frequency of the start time point of the time interval determined from the power grid response curve is obtained and used as the frequency threshold of the time interval.

9. A power regulation device, characterized in that, include: The power determination module is used to determine the current power deficit of the power grid and the power loss of new energy sources after a preset fault is detected in the power grid; the power loss of new energy sources is the sum of the power loss of new energy sources disconnecting from the grid and the temporary power loss due to low voltage. The power judgment module is used to determine whether the temporary power loss of low-voltage transmission is not greater than the current power deficit of the power grid when the power loss of the new energy source is greater than the current power deficit of the power grid. The first adjustment module is used to adjust the active power of the new energy unit according to the preset power adjustment strategy if the condition is met. The second adjustment module is used to adjust the active power of the new energy unit according to a preset power adjustment strategy if not, and to adjust the active power recovery slope of the new energy unit in different time periods to adjust the active power of the new energy unit; the preset power adjustment strategy includes a DC adjustment strategy and / or an emergency power strategy for energy storage.

10. An electronic device, characterized in that, include: Memory and processor; The memory is used to store programs; The processor calls the program and is used to execute the power regulation method as described in any one of claims 1-8.

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