Coordinated control method and system for direct-current energy consumption device and offshore wind turbine

Abstract

The invention relates to a coordination control method and system for a direct-current energy consumption device and an offshore wind turbine. The method comprises the following steps that operation data of a flexible direct-current system are obtained; the voltage of the direct current bus is monitored in real time, and when it is monitored that the land large power grid breaks down, the surplus power of the flexible direct current system is calculated; if the direct-current bus voltage exceeds a preset voltage threshold value, a direct-current energy consumption device is started, and a power consumption distribution problem is constructed and comprises a target function constructed with minimization of direct-current bus voltage regulation deviation and offshore wind turbine power regulation deviation as a target and constraint conditions constructed based on operation data; the power consumption distribution problem is solved, and the optimal consumption power of the direct-current energy consumption device and the optimal consumption power of the offshore wind turbine are obtained; the target power adjustment amount of each offshore wind turbine is calculated based on the optimal offshore wind turbine consumption power and the corresponding variable pitch response weight; and controlling the flexible direct current system based on the target power adjustment amount and the consumed power of the direct current energy consumption device.

Description

Technical Field

[0001] The present application relates to a field, mainly a method and system for coordinated control of a DC energy consumption device and an offshore wind turbine. Background Art

[0002] During offshore wind power transmission, electricity is converted to DC at an offshore converter station, transmitted via a DC submarine cable to an onshore converter station, and then converted to AC. Onshore converter stations typically have DC energy dissipation devices installed. When a fault in the onshore grid prevents power delivery, the DC bus voltage rises, and the DC energy dissipation devices are activated to absorb the excess power. However, relying solely on DC energy dissipation devices to absorb excess power can result in the devices being unable to absorb excess energy in a timely manner, exceeding the insulation tolerance of the equipment, triggering overvoltage protection (such as tripping the DC circuit breaker), and even causing permanent damage to the converter station equipment. Therefore, offshore wind turbines can be introduced for coordinated regulation to reduce the burden on DC energy dissipation devices.

[0003] However, traditional control strategies do not establish coordinated control logic between offshore wind turbines and DC energy-consuming devices, and only use DC energy-consuming devices as the sole means of regulation. DC energy-consuming devices need to bear all surplus power alone, which is prone to overload or frequent start-up and shutdown, shortening the life of the equipment. At the same time, due to the different hardware configurations and control strategies of various offshore wind turbines, there are differences in pitch response speed. Traditional strategies use a fixed power distribution ratio (such as average distribution). Such a fixed distribution strategy cannot adapt to the time-varying needs of multi-fault scenarios and is prone to cause regulation delays or local overregulation.

[0004] For example, the Chinese invention patent with the publication number of "CN116031925A" discloses "A coordination device for AC and DC energy consumption devices and its power control method", which specifically discloses "real-time monitoring of the DC line voltage in the coordination system of AC and DC energy consumption devices; when it is detected that a fault occurs in the receiving system connected to the onshore converter station, the AC bus voltage decreases and the DC line voltage increases, and the surplus power required to be consumed by the AC energy consumption device and the DC energy consumption device is calculated; when it is detected that the DC line voltage in the coordination system of AC and DC energy consumption devices is greater than the voltage threshold and the surplus power is less than the power threshold, the DC energy consumption device is put into use; when it is detected that the DC line voltage in the coordination system of AC and DC energy consumption devices is greater than the voltage threshold and the surplus power is less than the power threshold, the DC energy consumption device is put into use; when it is detected that the DC line voltage in the coordination system of AC and DC energy consumption devices is greater than the voltage threshold and the surplus power is less than the power threshold, the DC energy consumption device is put into use; When the power rate is greater than the power threshold, the AC energy consumption device and the DC energy consumption device are put into use simultaneously. However, this method does not specify the power allocation principle (such as capacity ratio and response speed priority) for the AC and DC energy consumption devices when they are put into use simultaneously, which may cause one device to be overloaded. For example, after the DC energy consumption device reaches its maximum power, the AC device still has residual capacity that is not used. Moreover, this method does not mention the minimum / maximum power limits of the energy consumption devices, which may cause the devices to operate under extreme conditions for a long time, resulting in equipment loss. In addition, this method does not consider the coordination of other controllable devices in the same converter station and relies only on single-point adjustment of the energy consumption device. This cannot form system-level synergy effects and cannot quantitatively evaluate the contribution of different allocation schemes to voltage stability, resulting in insufficient adjustment accuracy. Summary of the Invention

[0005] In order to solve the above-mentioned problems existing in the prior art, the present application provides a method and system for coordinated control of a DC energy consumption device and an offshore wind turbine.

[0006] The technical solution of this application is as follows:

[0007] In one aspect, the present invention provides a method for coordinated control of a DC energy consumption device and an offshore wind turbine, the method comprising:

[0008] Obtaining operational data of the flexible direct current system, which includes offshore wind turbines, an onshore power grid, and an onshore converter station, where the onshore converter station includes direct current energy consumption devices;

[0009] Real-time monitoring of the DC bus voltage of the flexible DC system. When a fault in the onshore power grid is detected, the system's surplus power is calculated based on operational data. The system also determines whether the DC bus voltage exceeds a preset threshold. If so, the DC energy dissipation device is activated.

[0010] Construct a power consumption allocation problem, including an objective function built to minimize the DC bus voltage regulation deviation and the offshore wind turbine power regulation deviation, and constraints based on operating data. Solve the power consumption allocation problem to obtain the optimal DC energy consumption device power consumption and the optimal offshore wind turbine power consumption.

[0011] The target power adjustment of each offshore wind turbine is calculated based on the optimal offshore wind turbine power consumption and the corresponding pitch response weight;

[0012] The flexible DC system is controlled based on the target power adjustment and the power consumption of the DC energy consuming device.

[0013] Preferably, the method further comprises performing data cleaning on the operating data, wherein the data cleaning comprises processing missing values, outliers and standardizing the data format.

[0014] Preferably, the surplus power of the flexible DC system is calculated by multiplying the DC side capacitance by the square difference between the DC bus voltage and the rated voltage in the operating data at a preset sampling time.

[0015] Preferably, the power consumption allocation problem, wherein:

[0016] The objective function of the power consumption allocation problem is specifically to weightedly calculate the DC bus voltage regulation deviation and the offshore wind turbine power regulation deviation and their corresponding allocation weight coefficients, wherein the allocation weight coefficients include a first allocation weight coefficient and a second allocation weight coefficient;

[0017] The objective function is constructed with the goal of minimizing the DC bus voltage regulation deviation and the offshore wind turbine power regulation deviation. The DC bus voltage regulation deviation is specifically the square of the difference between the DC bus voltage and the rated voltage at the current moment, and the offshore wind turbine power regulation deviation is specifically the square of the difference between the output power of the offshore wind turbine at the current moment and the target power.

[0018] The constraints include wind turbine power regulation range constraints, DC energy consumption device power consumption capacity constraints and power balance constraints;

[0019] The wind turbine power adjustment range constraint specifically means that the target power of the offshore wind turbine should be within a preset adjustable power range;

[0020] The power consumption capacity constraint of the DC energy consuming device is specifically that the power consumption of the DC energy consuming device should be between the minimum power and the maximum power of the DC energy consuming device;

[0021] The power balance constraint is specifically that the sum of the power consumed by the DC energy consuming device and the power consumed by the offshore wind turbine is the surplus power.

[0022] Preferably, the objective function of the power consumption allocation problem further includes dynamically adjusting the allocation weight coefficient, specifically:

[0023] If the surplus power exceeds a preset surplus threshold, the first allocation weight coefficient is increased so that the DC energy consumption device operates at maximum power, and the remaining surplus power is consumed by the offshore wind turbine;

[0024] If the surplus power is less than a preset surplus threshold, the second allocation weight coefficient is increased to increase the power consumption of the offshore wind turbine and reduce the power consumption of the DC energy consuming device.

[0025] Preferably, the target power adjustment amount of each offshore wind turbine is calculated based on the optimal offshore wind turbine power consumption and the corresponding pitch response weight, specifically:

[0026] Obtaining a pitch response speed of each offshore wind turbine, and calculating a ratio of the pitch response speed of each offshore wind turbine to the total pitch response speeds of all offshore wind turbines, where the ratio is the pitch response weight of each offshore wind turbine;

[0027] The optimal offshore wind turbine power consumption is multiplied by the corresponding pitch response weight to obtain the target power adjustment of each offshore wind turbine; the optimal offshore wind turbine power consumption is the difference between the surplus power and the optimal DC energy consumption device power consumption.

[0028] Preferably, the method further comprises determining whether the DC bus voltage exceeds a preset voltage threshold; if not, the DC energy consumption device is not started, and only the offshore wind turbine is used for power consumption.

[0029] The present invention also proposes a DC energy consumption device and an offshore wind turbine coordinated control system, the system comprising a data acquisition module, a power distribution module and a control module, wherein:

[0030] The data acquisition module is used to acquire operating data of the flexible direct current system, which includes an offshore wind turbine, an onshore large power grid and an onshore converter station, wherein the onshore converter station includes a direct current energy consumption device;

[0031] Monitor the DC bus voltage of the flexible DC system in real time. When a fault in the onshore power grid is detected, calculate the surplus power of the flexible DC system based on the operating data. Determine whether the DC bus voltage exceeds a preset voltage threshold. If so, activate the DC energy consumption device. Transmit the operating data and surplus power to the power distribution module.

[0032] The power allocation module is used to construct a power consumption allocation problem, including an objective function constructed with the goal of minimizing the DC bus voltage regulation deviation and the offshore wind turbine power regulation deviation, and constraints constructed based on operating data; solve the power consumption allocation problem to obtain the optimal DC energy consumption device power consumption and the optimal offshore wind turbine power consumption;

[0033] The target power adjustment of each offshore wind turbine is calculated based on the optimal offshore wind turbine power consumption and the corresponding pitch response weight;

[0034] The control module controls the flexible DC system based on the target power adjustment amount and the power consumed by the DC energy consuming device.

[0035] On the other hand, the present invention also proposes an electronic device, comprising a memory, a processor, and a computer program stored in the memory and runnable on the processor. When the processor executes the program, a DC energy consumption device and an offshore wind turbine coordinated control method as described in any embodiment of the present invention is implemented.

[0036] On the other hand, the present invention further provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements a coordinated control method of a DC energy consumption device and an offshore wind turbine as described in any embodiment of the present invention.

[0037] Compared with the prior art, the present invention has the following beneficial effects:

[0038] 1) The present invention provides a coordinated control method and system for a DC energy dissipation device and an offshore wind turbine. This method breaks the traditional limitation of relying solely on passive consumption by the energy dissipation device. It utilizes the active power control capability of the offshore wind turbine's variable pitch angle adjustment to reduce surplus power generation at the source, thereby forming a two-way collaboration with the DC energy dissipation device. By using the offshore wind turbine to share part of the surplus power, the risk of overload caused by the energy dissipation device bearing all the power alone is avoided.

[0039] 2) The present invention provides a method and system for coordinated control of DC energy consumption devices and offshore wind turbines, which constructs a power consumption allocation problem with the goals of "minimizing DC bus voltage regulation deviation" and "minimizing offshore wind turbine power regulation deviation". Combining constraints such as the wind turbine's adjustable power range and energy consumption device capacity limitations, the target power of the energy consumption device and each wind turbine can be accurately calculated. Moreover, the power adjustment amount of the offshore wind turbine is limited within the adjustable range, avoiding equipment loss caused by mechanical overload of the wind turbine due to uneven distribution. At the same time, the energy consumption device operates in a safe power range, extending the service life of the device, enhancing system resource utilization efficiency, and reducing redundant energy consumption.

[0040] 3) The present invention provides a method and system for coordinated control of a DC energy consumption device and an offshore wind turbine, which automatically switches the power consumption distribution strategy by dynamically adjusting the weight distribution. At the same time, a pitch response speed weight is introduced to convert the difference in wind turbine pitch rate into a basis for power distribution, thereby avoiding the aggravation of voltage fluctuations due to insufficient power distribution for slow-responding wind turbines, or power limitation due to overload risks for fast-responding wind turbines, thereby improving energy utilization. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 is a flow chart of an embodiment of the present invention. DETAILED DESCRIPTION

[0042] The specific embodiments of the present invention are described below to facilitate understanding of the present invention by those skilled in the art. However, it should be clear that the present invention is not limited to the scope of the specific embodiments. For those skilled in the art, as long as various changes are within the spirit and scope of the present invention as defined and determined by the appended claims, these changes are obvious, and all inventions and creations utilizing the concepts of the present invention are protected.

[0043] The present invention provides the following technical solution: a DC energy consumption device and an offshore wind turbine coordinated control method and system.

[0044] Example 1:

[0045] See Figure 1 This embodiment provides a coordinated control method for a DC energy consumption device and an offshore wind turbine, the specific steps of which include:

[0046] S1. Obtaining operational data of the flexible direct current system, which includes offshore wind turbines, an onshore power grid, and an onshore converter station, wherein the onshore converter station includes a direct current energy consumption device;

[0047] The method further includes performing data cleaning on the operating data, wherein the data cleaning includes processing missing values, outliers and standardizing the data format;

[0048] S2: Real-time monitoring of the DC bus voltage of the flexible DC system. When a fault in the onshore power grid is detected, the surplus power of the flexible DC system is calculated based on the operating data.

[0049] When a fault occurs in the onshore power grid, the surplus power of the flexible DC system will cause the DC bus voltage to rise. To ensure equipment safety, the surplus power must be consumed or transferred in a timely manner. This embodiment uses DC energy consumption devices and offshore wind turbines to coordinate power consumption.

[0050] The calculation process of the surplus power of the flexible DC system is to multiply the square difference between the DC bus voltage and the rated voltage in the operating data by the DC side capacitance at a preset sampling time, which can be expressed as follows:

[0051]

[0052] Where, P surplus represents the surplus power of the flexible DC system; U dc Indicates DC bus voltage; C indicates DC side capacitance; U dcN Indicates rated voltage; Δs indicates sampling time;

[0053] S3, determining whether the DC bus voltage exceeds a preset voltage threshold, and if so, starting the DC energy consumption device;

[0054] S4. Constructing a power consumption allocation problem, including an objective function constructed with the goal of minimizing the DC bus voltage regulation deviation and the offshore wind turbine power regulation deviation, and constraints constructed based on operating data;

[0055] S41. The objective function of the power consumption allocation problem is specifically to calculate the DC bus voltage regulation deviation and the offshore wind turbine power regulation deviation and their corresponding allocation weight coefficients, wherein the allocation weight coefficients include a first allocation weight coefficient and a second allocation weight coefficient;

[0056] The objective function is constructed with the goal of minimizing the DC bus voltage regulation deviation and the offshore wind turbine power regulation deviation. The DC bus voltage regulation deviation is specifically the square of the difference between the DC bus voltage and the rated voltage at the current moment, and the offshore wind turbine power regulation deviation is specifically the square of the difference between the output power of the offshore wind turbine at the current moment and the target power.

[0057] The objective function of the power consumption allocation problem is expressed as follows:

[0058]

[0059] Where J represents the objective function of the power consumption allocation problem; U dc (s) represents the DC bus voltage at time s; λ1 represents the first allocation weight coefficient; λ2 represents the second allocation weight coefficient; n represents the number of offshore wind turbines; i represents the index value of the i-th offshore wind turbine; P i (s) represents the output power of the i-th offshore wind turbine at time s; P i_target (s) represents the target power of the i-th offshore wind turbine at time s; s represents the time;

[0060] S42, the constraints include wind turbine power adjustment range constraint, DC energy consumption device power consumption capacity constraint and power balance constraint;

[0061] The wind turbine power adjustment range constraint specifically means that the target power of the offshore wind turbine should be within a preset adjustable power range, expressed as P imin ≤P i_target ≤P imax , where P imin Indicates the lower limit of the adjustable power range; P imax Indicates the upper limit of the adjustable power range; P i_target represents the target power of the i-th offshore wind turbine;

[0062] The power consumption capacity constraint of the DC energy consumption device is specifically that the power consumption of the DC energy consumption device should be between the minimum power and the maximum power of the DC energy consumption device, expressed as P dccmin ≤P dcc ≤P dccmax , where P dccmin Indicates the minimum power of the DC energy consumption device; P dccmax Indicates the maximum power of the DC energy consumption device; P dcc Indicates the power consumed by the DC energy consuming device;

[0063] The power balance constraint is specifically that the sum of the power consumed by the DC energy consumption device and the power consumed by the offshore wind turbine is the surplus power, which is expressed as Among them, P i (0) represents the output power of the i-th offshore wind turbine before the fault;

[0064] S43, the objective function of the power consumption allocation problem further includes dynamically adjusting the allocation weight coefficient, specifically:

[0065] If the surplus power exceeds a preset surplus threshold, the first allocation weight coefficient is increased so that the DC energy consumption device operates at maximum power, and the remaining surplus power is consumed by the offshore wind turbine;

[0066] If the surplus power is less than a preset surplus threshold, the power consumption of the offshore wind turbine is increased and the power consumption of the DC energy consumption device is reduced by increasing the second allocation weight coefficient;

[0067] S5. Solve the power consumption allocation problem to obtain the optimal DC energy consumption device power consumption and the optimal offshore wind turbine power consumption;

[0068] S6. Calculate a target power adjustment for each offshore wind turbine based on the optimal offshore wind turbine power consumption and the corresponding pitch response weight;

[0069] Obtain the pitch response speed of each offshore wind turbine, and calculate the ratio of the pitch response speed of each offshore wind turbine to the total pitch response speed of all offshore wind turbines. The ratio is the pitch response weight of each offshore wind turbine, which is expressed as follows:

[0070]

[0071] Where w i represents the weight of the i-th offshore wind turbine; v i represents the pitch response speed of the i-th offshore wind turbine;

[0072] The optimal offshore wind turbine power consumption is multiplied by the corresponding pitch response weight to obtain the target power adjustment of each offshore wind turbine. The optimal offshore wind turbine power consumption is the difference between the surplus power and the optimal DC energy consumption device power consumption, which can be expressed as follows:

[0073] ΔP i_targer =w i ·P i ';

[0074] P i '=P surplus -P′ dcc ;

[0075] Where ΔP i_targer represents the target power adjustment of the i-th offshore wind turbine; P i ' represents the power consumption of the i-th optimal offshore wind turbine; P' dcc Indicates the power consumed by the optimal DC energy consumption device;

[0076] S7, controlling the flexible DC system based on the target power adjustment amount and the power consumed by the DC energy consuming device;

[0077] S8. The method further includes determining whether the DC bus voltage exceeds a preset voltage threshold; if not, not starting the DC energy consumption device and only using the offshore wind turbine for power consumption;

[0078] S9. The method further includes verifying whether the optimal DC energy consumption device power consumption, the optimal offshore wind turbine power consumption, and the target power adjustment amount of each offshore wind turbine meet the constraint conditions;

[0079] S10, the method further includes: if the current surplus power is still greater than 0 after the power is consumed by the DC energy consumption device and the offshore wind turbine, it is necessary to consume it in other ways;

[0080] The other methods include adding additional energy consumption devices, dynamically adjusting offshore wind turbine control parameters such as the pitch response speed of offshore wind turbines, and configuring battery energy storage systems.

[0081] In this embodiment, a sudden short circuit fault occurs in the onshore power grid, and the DC line power cannot be transmitted, causing the DC bus voltage to rise from the rated voltage of 500 kV to 520 kV. The preset voltage threshold is 520 kV, the DC bus capacitance C = 0.1 F, the maximum power of the DC energy consumption device is 20 MW, and the minimum power of the DC energy consumption device is 5 MW; the preset surplus threshold is 25 MW.

[0082] The flexible direct current system is connected to three wind turbines, namely A, B and C; the pitch response speed corresponding to wind turbine A is 5° / s, and the adjustable power range is [0, 15]; the pitch response speed corresponding to wind turbine B is 3° / s, and the adjustable power range is [0, 10]; the pitch response speed corresponding to wind turbine C is 4° / s, and the adjustable power range is [0, 12];

[0083] The DC bus voltage rises to 550kV, exceeding the preset voltage threshold of 520kV, triggering a fault response;

[0084] Set the sampling interval to 0.1 seconds and calculate the surplus power of the flexible DC system as:

[0085] Determine that the DC bus voltage 520kV is equal to the preset voltage threshold 520kV, and start the DC energy consumption device;

[0086] Constructing the objective function of the power consumption allocation problem

[0087] The wind turbine power regulation range constraint in the constraint condition is expressed as 0≤P A ≤15,0≤P B ≤10,0≤P C ≤12; the power consumption capacity constraint of DC energy consumption device is expressed as 5≤P dcc ≤20 and the power balance constraint is expressed as P dcc +P A +P B +P C =20.4MW;

[0088] The current surplus power is 20.4MW, which does not exceed the preset surplus threshold of 25MW. The second allocation weight coefficient is increased to prioritize power consumption by offshore wind turbines, reducing the burden on DC energy consumption devices.

[0089] Solve the power consumption allocation problem, assuming that the optimal DC energy consumption device power consumption is P' dcc =8.4MW, the remaining surplus power is allocated to the optimal offshore wind turbine with a power consumption of P A +P B +P C =20.4-8.4=12MW;

[0090] Calculate the weight of each offshore wind turbine and get w A =0.417, w B =0.25, w C =0.333;

[0091] Calculate the target power adjustment for each offshore wind turbine to obtain ΔP A =w A·(P A +P B +P C ) = 0.417 × 12 ≈ 5 MW, which is within the adjustable power range [0, 15] of wind turbine A;

[0092] Get ΔP B =w B ·(P A +P B +P C ) = 0.25 × 12 = 3 MW, which is within the adjustable power range [0, 10] of wind turbine B;

[0093] Get ΔP C =w C ·(P A +P B +P C ) = 0.333 × 12 ≈ 4 MW, which is within the adjustable power range [0, 12] of wind turbine C;

[0094] To verify, the total power consumption is P dcc +P A +P B +P C =P surplus , meeting the power balance constraint; the target power of the remaining offshore wind turbines is within the adjustable power range, and the power consumption of the DC energy consumption device is also between the minimum power and maximum power of the DC energy consumption device;

[0095] In another embodiment, a sudden short circuit fault occurs in the onshore power grid, and the DC line power cannot be transmitted, causing the DC bus voltage to rise from the rated voltage of 500 kV to 580 kV. The preset voltage threshold is 520 kV, the DC bus capacitance C = 0.2 F, the maximum power of the DC energy consumption device is 20 MW, and the minimum power of the DC energy consumption device is 5 MW; the preset surplus threshold is 25 MW.

[0096] The flexible direct current system is connected to four wind turbines, namely A, B, C and D; the pitch response speed corresponding to wind turbine A is 6° / s, and the adjustable power range is [0, 60]; the pitch response speed corresponding to wind turbine B is 4° / s, and the adjustable power range is [0, 40]; the pitch response speed corresponding to wind turbine C is 5° / s, and the adjustable power range is [0, 45]; the pitch response speed corresponding to wind turbine D is 3° / s, and the adjustable power range is [0, 30];

[0097] The DC bus voltage rises to 580kV, exceeding the preset voltage threshold of 520kV, triggering a fault response;

[0098] Set the sampling interval to 0.1 seconds and calculate the surplus power of the flexible DC system as:

[0099] It is determined that the DC bus voltage of 580kV is greater than the preset voltage threshold of 520kV, and the DC energy consumption device is started;

[0100] Constructing the objective function of the power consumption allocation problem

[0101] The wind turbine power regulation range constraint in the constraint condition is expressed as 0≤P A ≤60,0≤P B ≤40,0≤P C ≤40,0≤P D ≤20; the power consumption capacity constraint of DC energy consumption device is expressed as 5≤P dcc ≤20 and the power balance constraint is expressed as P dcc +P A +P B +P C +P D =172.8MW;

[0102] The current surplus power is 172.8MW, exceeding the preset surplus threshold of 25MW. The first allocation weight coefficient is increased, causing the DC energy consumption device to operate at maximum power, and the remaining surplus power is consumed by the offshore wind turbine.

[0103] Solve the power consumption allocation problem and get the optimal DC energy consumption device power consumption P′ dcc =20MW, which is the maximum power. The remaining surplus power is allocated to the optimal offshore wind turbine, which consumes power P A +P B +P C +P D =172.8-20=152.8MW;

[0104] Calculate the weight of each offshore wind turbine and get w A =0.333, w B =0.222, w C =0.278, w D =0.167;

[0105] Calculate the target power adjustment for each offshore wind turbine to obtain ΔP A =w A ·(P A +P B +P C +P D )=0.333×152.8≈50.93MW, which does not exceed the adjustable power range of wind turbine A [0, 60];

[0106] Get ΔP B=w B ·(P A +P B +P C +P D )=0.222×152.8≈33.96MW, which does not exceed the adjustable power range of wind turbine B [0, 40];

[0107] Get ΔP C =w C ·(P A +P B +P C +P D ) = 0.278 × 152.8 ≈ 42.44 MW, which is within the adjustable power range [0, 45] of wind turbine C;

[0108] Get ΔP D =w D ·(P A +P B +P C +P D ) = 0.167 × 152.8 ≈ 25.47 MW, which is within the adjustable power range [0, 30] of wind turbine C;

[0109] To verify, the total power consumption is P dcc +P A +P B +P C +P D =P surplus , meeting the power balance constraint; the target power of the remaining offshore wind turbines is within the adjustable power range, and the power consumption of the DC energy consumption device is also between the minimum power and maximum power of the DC energy consumption device;

[0110] In another embodiment, a sudden short circuit fault occurs in the onshore power grid, and the DC line power cannot be transmitted, causing the DC bus voltage to rise from the rated voltage of 500 kV to 600 kV. The preset voltage threshold is 520 kV, the DC bus capacitance C = 0.2 F, the maximum power of the DC energy consumption device is 20 MW, and the minimum power of the DC energy consumption device is 5 MW; the preset surplus threshold is 25 MW.

[0111] The flexible direct current system is connected to four wind turbines, namely A, B, C and D; the pitch response speed corresponding to wind turbine A is 6° / s, and the adjustable power range is [0, 60]; the pitch response speed corresponding to wind turbine B is 4° / s, and the adjustable power range is [0, 40]; the pitch response speed corresponding to wind turbine C is 5° / s, and the adjustable power range is [0, 45]; the pitch response speed corresponding to wind turbine D is 3° / s, and the adjustable power range is [0, 30];

[0112] The DC bus voltage rises to 600kV, exceeding the preset voltage threshold of 520kV, triggering a fault response;

[0113] Set the sampling interval to 0.1 seconds and calculate the surplus power of the flexible DC system as:

[0114] At this time, P surplus >P dcc +P A +P B +P C +P D , there is still surplus power of 220-20-60-40-45-30=25MW, which cannot be consumed by DC energy consumption devices and offshore wind turbines and needs to be consumed by other means.

[0115] Example 2:

[0116] The present invention also provides a DC energy consumption device and an offshore wind turbine coordinated control system, the system comprising a data acquisition module, a power distribution module and a control module, wherein:

[0117] The data acquisition module is used to acquire operating data of the flexible direct current system, which includes an offshore wind turbine, an onshore large power grid and an onshore converter station, wherein the onshore converter station includes a direct current energy consumption device;

[0118] Monitor the DC bus voltage of the flexible DC system in real time. When a fault in the onshore power grid is detected, calculate the surplus power of the flexible DC system based on the operating data. Determine whether the DC bus voltage exceeds a preset voltage threshold. If so, activate the DC energy consumption device. Transmit the operating data and surplus power to the power distribution module.

[0119] The power allocation module is used to construct a power consumption allocation problem, including an objective function constructed with the goal of minimizing the DC bus voltage regulation deviation and the offshore wind turbine power regulation deviation, and constraints constructed based on operating data; solve the power consumption allocation problem to obtain the optimal DC energy consumption device power consumption and the optimal offshore wind turbine power consumption;

[0120] The target power adjustment of each offshore wind turbine is calculated based on the optimal offshore wind turbine power consumption and the corresponding pitch response weight;

[0121] The control module controls the flexible DC system based on the target power adjustment amount and the power consumed by the DC energy consuming device.

[0122] Example 3:

[0123] This embodiment provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the program, a DC energy consumption device and an offshore wind turbine coordinated control method as described in any embodiment of the present invention is implemented.

[0124] Example 4:

[0125] This embodiment provides a computer-readable storage medium having a computer program stored thereon. When the program is executed by a processor, a coordinated control method of a DC energy consumption device and an offshore wind turbine as described in any embodiment of the present invention is implemented.

[0126] It is worth noting that the system, electronic device and computer-readable storage medium described in the present invention are all based on the same principles as the method described in Example 1, and will not be repeated here.

[0127] The above descriptions are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention's description and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A coordinated control method for a DC energy consumption device and an offshore wind turbine, characterized in that: The method comprises: Obtaining operational data of the flexible direct current system, which includes offshore wind turbines, an onshore power grid, and an onshore converter station, where the onshore converter station includes direct current energy consumption devices; Real-time monitoring of the DC bus voltage of the flexible DC system. When a fault in the onshore power grid is detected, the system's surplus power is calculated based on operational data. The system also determines whether the DC bus voltage exceeds a preset threshold. If so, the DC energy dissipation device is activated. Construct a power consumption allocation problem, including an objective function built to minimize the DC bus voltage regulation deviation and the offshore wind turbine power regulation deviation, and constraints based on operating data. Solve the power consumption allocation problem to obtain the optimal DC energy consumption device power consumption and the optimal offshore wind turbine power consumption. The target power adjustment of each offshore wind turbine is calculated based on the optimal offshore wind turbine power consumption and the corresponding pitch response weight; The flexible DC system is controlled based on the target power adjustment and the power consumption of the DC energy consuming device.

2. A coordinated control method for a DC energy consumption device and an offshore wind turbine according to claim 1, characterized in that: The method further includes performing data cleaning on the operating data, wherein the data cleaning includes processing missing values, outliers and standardizing data formats.

3. The coordinated control method of a DC energy consumption device and an offshore wind turbine according to claim 1, characterized in that: The surplus power of the flexible DC system is calculated by multiplying the DC link capacitance by the square difference between the DC bus voltage and the rated voltage in the operating data at a preset sampling time.

4. A coordinated control method for a DC energy consumption device and an offshore wind turbine according to claim 1, characterized in that: The power consumption allocation problem, wherein: The objective function of the power consumption allocation problem is specifically to weightedly calculate the DC bus voltage regulation deviation and the offshore wind turbine power regulation deviation and their corresponding allocation weight coefficients, wherein the allocation weight coefficients include a first allocation weight coefficient and a second allocation weight coefficient; The objective function is constructed with the goal of minimizing the DC bus voltage regulation deviation and the offshore wind turbine power regulation deviation. The DC bus voltage regulation deviation is specifically the square of the difference between the DC bus voltage and the rated voltage at the current moment, and the offshore wind turbine power regulation deviation is specifically the square of the difference between the output power of the offshore wind turbine at the current moment and the target power. The constraints include wind turbine power regulation range constraints, DC energy consumption device power consumption capacity constraints and power balance constraints; The wind turbine power adjustment range constraint specifically means that the target power of the offshore wind turbine should be within a preset adjustable power range; The power consumption capacity constraint of the DC energy consuming device is specifically that the power consumption of the DC energy consuming device should be between the minimum power and the maximum power of the DC energy consuming device; The power balance constraint is specifically that the sum of the power consumed by the DC energy consuming device and the power consumed by the offshore wind turbine is the surplus power.

5. A coordinated control method of a DC energy consumption device and an offshore wind turbine according to claim 4, characterized in that: The objective function of the power consumption allocation problem further includes dynamically adjusting the allocation weight coefficient, specifically: If the surplus power exceeds a preset surplus threshold, the first allocation weight coefficient is increased so that the DC energy consumption device operates at maximum power, and the remaining surplus power is consumed by the offshore wind turbine; If the surplus power is less than a preset surplus threshold, the second allocation weight coefficient is increased to increase the power consumption of the offshore wind turbine and reduce the power consumption of the DC energy consuming device.

6. The coordinated control method of a DC energy consumption device and an offshore wind turbine according to claim 1, characterized in that: The target power adjustment of each offshore wind turbine is calculated based on the optimal offshore wind turbine power consumption and the corresponding pitch response weight: Obtaining a pitch response speed of each offshore wind turbine, and calculating a ratio of the pitch response speed of each offshore wind turbine to the total pitch response speeds of all offshore wind turbines, where the ratio is the pitch response weight of each offshore wind turbine; The optimal offshore wind turbine power consumption is multiplied by the corresponding pitch response weight to obtain the target power adjustment of each offshore wind turbine; the optimal offshore wind turbine power consumption is the difference between the surplus power and the optimal DC energy consumption device power consumption.

7. The coordinated control method of a DC energy consumption device and an offshore wind turbine according to claim 1, characterized in that: The method further includes determining whether the DC bus voltage exceeds a preset voltage threshold; if not, the DC energy consumption device is not started, and only the offshore wind turbine is used for power consumption.

8. A DC energy consumption device and offshore wind turbine coordinated control system, characterized in that: The system includes a data acquisition module, a power distribution module and a control module, wherein: The data acquisition module is used to acquire operating data of the flexible direct current system, which includes an offshore wind turbine, an onshore large power grid and an onshore converter station, wherein the onshore converter station includes a direct current energy consumption device; Monitor the DC bus voltage of the flexible DC system in real time. When a fault in the onshore power grid is detected, calculate the surplus power of the flexible DC system based on the operating data. Determine whether the DC bus voltage exceeds a preset voltage threshold. If so, activate the DC energy consumption device. Transmit the operating data and surplus power to the power distribution module. The power allocation module is used to construct a power consumption allocation problem, including an objective function constructed with the goal of minimizing the DC bus voltage regulation deviation and the offshore wind turbine power regulation deviation, and constraints constructed based on operating data; solve the power consumption allocation problem to obtain the optimal DC energy consumption device power consumption and the optimal offshore wind turbine power consumption; The target power adjustment of each offshore wind turbine is calculated based on the optimal offshore wind turbine power consumption and the corresponding pitch response weight; The control module controls the flexible DC system based on the target power adjustment amount and the power consumed by the DC energy consuming device.

9. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein: When the processor executes the program, the method for coordinated control of a DC energy consumption device and an offshore wind turbine according to any one of claims 1 to 7 is implemented.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the program is executed by a processor, a coordinated control method of a DC energy consumption device and an offshore wind turbine as claimed in any one of claims 1 to 7 is implemented.

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