Method for determining frequency index of offshore oil and gas field power grid suitable for wind power access

Abstract

The present invention provides a method for determining frequency index of an offshore oil and gas field power grid suitable for wind power access, and relates to the technical field of microgrids. The method comprises: determining equivalent parameters of the power generation system according to the rated power, governor proportional coefficient, prime mover time constant, inertia time constant and damping coefficient of each generator set started in the power generation system of the offshore oil and gas field power grid, and the equivalent parameters include governor proportional coefficient, prime mover time constant, inertia time constant and damping coefficient; determining the output frequency index of the power generation system based on the equivalent parameters and the operating parameters of the wind turbine set connected to the offshore oil and gas field power grid, and the output frequency index includes the maximum frequency deviation and the steady-state frequency deviation. The present invention can realize the quantitative analysis of the frequency index of the offshore oil and gas field power grid to which wind power is added.

Description

Technical Field

[0001] The present invention relates to the field of microgrids, and in particular to a method for determining frequency indicators of offshore oil and gas field power grids suitable for wind power access. Background Art

[0002] As an integrated oil and gas production, gathering and transportation system, offshore oil and gas fields usually use gas or oil-fired generators on multiple platforms to supply energy during the production, gathering and transportation of offshore oil and gas. When offshore wind turbines are connected to the grid, the offshore oil and gas platform function system will change from the original isolated function system to a multi-energy system operated in coordination with offshore wind power and gas / oil turbine generators. This system is an offshore wind power coordinated energy supply system with wind, gas and oil as the main body. Excess oil and gas are transported by ship or pipeline through oil pumps and compressors.

[0003] The operation of offshore wind turbines is affected by the weather and has natural uncertainty. After offshore wind power is connected to the grid, turbine generator sets become the only power source to smooth out the uncertainty of wind power. In the off-grid operation mode, the energy system of the offshore platform group, which is synergistically powered by offshore wind power, achieves energy self-sufficiency through offshore wind power and turbine generator sets. During the off-peak period of offshore wind power, it mainly relies on turbine generator sets to consume self-produced natural gas and crude oil to supply electricity. During the peak period of offshore wind power, turbine generator sets will reduce their output to improve the absorption level of offshore wind power.

[0004] When offshore wind power, an uncertain function, is connected to the normal operation of the offshore oil and gas platform power grid, the energy demand fluctuation of the offshore oil and gas platform is small, so when smoothing the frequency fluctuation, the frequency fluctuation impact caused by wind power access must be considered. However, in the prior art, the output frequency index fluctuation analysis of the power generation system of offshore oil and gas fields is mainly applicable to conventional offshore oil and gas platforms, and there is no quantitative analysis method for the output frequency index of the offshore oil and gas field power grid connected to wind power. Summary of the invention

[0005] The present invention provides a method for determining frequency index of an offshore oil and gas field power grid suitable for wind power access, so as to solve the defect that there is no output frequency fluctuation index analysis method for an offshore oil and gas field power grid connected to wind power in the prior art, and realize the output frequency index fluctuation analysis of an offshore oil and gas field power grid suitable for wind power access.

[0006] The present invention provides a method for determining frequency index of offshore oil and gas field power grid applicable to wind power access, the method comprising:

[0007] Determine equivalent parameters of the power generation system according to the rated power, governor proportional coefficient, prime mover time constant, inertia time constant and damping coefficient of each generator set started in the power generation system of the offshore oil and gas field power grid, wherein the equivalent parameters include the governor proportional coefficient, prime mover time constant, inertia time constant and damping coefficient;

[0008] The output frequency index of the power generation system is determined based on the equivalent parameters and the operating parameters of the wind turbine group connected to the offshore oil and gas field power grid. The output frequency index includes the maximum frequency deviation when the wind turbine group is in normal operating state, and the maximum frequency deviation and steady-state frequency deviation when the wind turbine group is in a fault-off-grid state.

[0009] According to a method for determining a frequency index of an offshore oil and gas field power grid suitable for wind power access provided by the present invention, the output frequency index of the power generation system is determined based on the equivalent parameter and the operating parameters of the wind turbine generator set connected to the offshore oil and gas field power grid, including:

[0010] The maximum frequency deviation of the wind turbine generator set when it is in a normal operating state is determined based on a first preset formula, where the first preset formula is:

[0011] ;

[0012] in, represents the maximum frequency deviation of the power generation system when the wind turbine is in normal operation, It represents the fluctuation ratio of the wind power of the wind turbine in unit time, , represents the governor proportional coefficient in the equivalent parameters of the power generation system, and D represents the damping coefficient in the equivalent parameters of the power generation system.

[0013] According to a method for determining a frequency index of an offshore oil and gas field power grid suitable for wind power access provided by the present invention, the output frequency index of the power generation system is determined based on the equivalent parameter and the operating parameters of the wind turbine generator set connected to the offshore oil and gas field power grid, including:

[0014] The maximum frequency deviation when the wind turbine generator set is in an off-grid fault state is determined based on a second preset formula, where the second preset formula is:

[0015] ;

[0016] ;

[0017] ;

[0018] ;

[0019] , ;

[0020] in, represents the maximum frequency deviation of the power generation system when the wind turbine is in a grid-off fault state, represents the upper limit of the output power of the wind turbine, H and D represent the inertia time constant and damping coefficient in the equivalent parameters of the power generation system respectively, represents the prime mover constant among the equivalent parameters of the power generation system, , It represents the governor proportional coefficient in the equivalent parameters of the power generation system.

[0021] According to a method for determining a frequency index of an offshore oil and gas field power grid suitable for wind power access provided by the present invention, the output frequency index of the power generation system is determined based on the equivalent parameter and the operating parameters of the wind turbine generator set connected to the offshore oil and gas field power grid, including:

[0022] The steady-state frequency deviation of the wind turbine generator set when it is in a grid-off fault state is determined based on a third preset formula, wherein the third preset formula is:

[0023] ;

[0024] in, represents the steady-state frequency deviation of the power generation system when the wind turbine is in a grid-off fault state, represents the upper limit of the output power of the wind turbine generator set, , represents the governor proportional coefficient in the equivalent parameters of the power generation system, and D represents the damping coefficient in the equivalent parameters of the power generation system.

[0025] According to a method for determining a frequency index of an offshore oil and gas field power grid applicable to wind power access provided by the present invention, after determining the output frequency index of the power generation system based on the equivalent parameter and the operating parameters of the wind turbine generator set connected to the offshore oil and gas field power grid, the method comprises:

[0026] Based on the output frequency index of the power generation system, an operation constraint condition of the power generation system is constructed, and the operation constraint condition is used to adjust the scheduling plan of the offshore oil and gas field power grid.

[0027] According to a method for determining frequency index of an offshore oil and gas field power grid applicable to wind power access provided by the present invention, the operating constraint conditions of the power generation system are constructed based on the output frequency index of the power generation system, including:

[0028] Constructing a constraint condition function that the maximum frequency deviation of the wind turbine generator set when it is in a grid-off fault state is less than a maximum frequency deviation threshold;

[0029] The constraint condition function is converted into a quadratic convex constraint function about the inertia time constant in the equivalent parameters of the power generation system and the prime mover inter-constant in the equivalent parameters of the power generation system.

[0030] The present invention also provides a device for determining frequency index of offshore oil and gas field power grid suitable for wind power access, the device comprising:

[0031] An equivalent parameter determination module is used to determine the equivalent parameters of the power generation system according to the rated power, governor proportional coefficient, prime mover time constant, inertia time constant and damping coefficient of each generator set started in the power generation system of the offshore oil and gas field power grid, wherein the equivalent parameters include the governor proportional coefficient, prime mover time constant, inertia time constant and damping coefficient;

[0032] The frequency index determination module is used to determine the output frequency index of the power generation system based on the equivalent parameters and the operating parameters of the wind turbine group connected to the offshore oil and gas field power grid, and the output frequency index includes a maximum frequency deviation and a steady-state frequency deviation.

[0033] The present invention also provides 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 computer program, it implements any of the above-described methods for determining frequency indicators of offshore oil and gas field power grids applicable to wind power access.

[0034] The present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements any of the above-described methods for determining frequency indicators of offshore oil and gas field power grids applicable to wind power access.

[0035] The present invention also provides a computer program product, comprising a computer program, wherein when the computer program is executed by a processor, the method for determining a frequency index of an offshore oil and gas field power grid applicable to wind power access as described in any one of the above methods.

[0036] The method for determining frequency index of an offshore oil and gas field power grid suitable for wind power access provided by the present invention determines equivalent parameters of the power generation system according to the rated power, governor proportional coefficient, prime mover time constant, inertia time constant and damping coefficient of each generator set started in the power generation system of the offshore oil and gas field power grid, wherein the equivalent parameters include the governor proportional coefficient, prime mover time constant, inertia time constant and damping coefficient, and determines the frequency index of the power generation system including the maximum frequency deviation and the steady-state frequency deviation based on the equivalent parameters of the power generation system and the operating parameters of the wind turbine sets connected to the offshore oil and gas field power grid, thereby realizing quantitative analysis of the frequency index of the offshore oil and gas field power grid to which wind power is added. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0038] Figure 1 It is a flow chart of a method for determining frequency index of an offshore oil and gas field power grid applicable to wind power access provided by the present invention.

[0039] Figure 2 It is a structural schematic diagram of an experimental system for a method for determining frequency index of an offshore oil and gas field power grid suitable for wind power access provided by the present invention.

[0040] Figure 3 This is a schematic diagram of the experimental effect of the method for determining the frequency index of offshore oil and gas field power grid applicable to wind power access provided by the present invention. Figure 1 .

[0041] Figure 4 This is a schematic diagram of the experimental effect of the method for determining the frequency index of offshore oil and gas field power grid applicable to wind power access provided by the present invention. Figure 2 .

[0042] Figure 5 This is a schematic diagram of the experimental effect of the method for determining the frequency index of offshore oil and gas field power grid applicable to wind power access provided by the present invention. Figure 3 .

[0043] Figure 6 It is a structural schematic diagram of a frequency index determination device for an offshore oil and gas field power grid suitable for wind power access provided by the present invention.

[0044] Figure 7 It is a structural schematic diagram of the electronic device provided by the present invention. DETAILED DESCRIPTION

[0045] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0046] Combine the following Figure 1-5 The present invention provides a method for determining frequency index of offshore oil and gas field power grids applicable to wind power access. Figure 1 As shown, the method for determining the frequency index of an offshore oil and gas field power grid applicable to wind power access provided by the present invention comprises the following steps:

[0047] S110, determining equivalent parameters of the power generation system according to the rated power, governor proportional coefficient, prime mover time constant, inertia time constant and damping coefficient of each generator set started in the power generation system of the offshore oil and gas field power grid, the equivalent parameters including the governor proportional coefficient, prime mover time constant, inertia time constant and damping coefficient;

[0048] S120. Determine an output frequency index of the power generation system based on equivalent parameters and operating parameters of the wind turbine generator set connected to the offshore oil and gas field power grid. The output frequency index includes a maximum frequency deviation when the wind turbine generator set is in a normal operating state, and a maximum frequency deviation and a steady-state frequency deviation when the wind turbine generator set is in a fault-offline state.

[0049] In the method provided by the present invention, the power generation system of the offshore oil and gas field power grid includes multiple generator sets and is connected to wind power. The generator set is a turbine generator set, which can be a fuel generator set or a gas generator set. The frequency model of the generator set can be regarded as a combination of a speed governor, a prime mover, and a synchronous generator. That is, the frequency of the generator set is related to the parameters of the speed governor, the prime mover, and the synchronous generator. The speed governor, the prime mover, and the synchronous generator together constitute the frequency response dynamics of the generator set. In actual operation, multiple generator sets may be partially turned on and partially turned off. For the generator sets that are started, in the method provided by the present invention, all the generator sets that are started are regarded as an aggregated frequency response model, and the corresponding equivalent parameters include the speed governor proportional parameter, the prime mover time constant, the inertia time constant, and the damping coefficient. That is to say, for a single generator set, its speed governor proportional coefficient, the prime mover time constant, the inertia time constant, and the damping coefficient are determined, but in the method provided by the present invention, all the generator sets that are started are regarded as an aggregated generator set, and the frequency change is determined according to the speed governor proportional coefficient, the prime mover time constant, the inertia time constant, and the damping coefficient of the aggregated generator set.

[0050] Specifically, the calculation process of each equivalent parameter of the power generation system in the offshore oil and gas field power grid can be expressed by the formula:

[0051] ;

[0052] ;

[0053] ;

[0054] ;

[0055] Wherein, H and D represent the inertia time constant and damping coefficient of the equivalent parameters of the power generation system in the offshore oil and gas field power grid, respectively; is the collection of gas / oil generator sets in OPCES, and ; Turbine generator set The start and stop status of the generator set, such as At startup, ,otherwise ; and Indicates the generator set The inertia time constant and damping coefficient of the synchronous generator; s is the Laplace operator, Indicates the generator set Rated power, Expressing the governor proportionality factor in the equivalent parameters of the power generation system in the offshore oil and gas field power grid; Represents the prime mover constant in the equivalent parameters of the power generation system in the offshore oil and gas field power grid; Turbine generator set The proportional coefficient of the speed regulator; Turbine generator set The time constant of the prime mover.

[0056] In an offshore oil and gas field power grid connected to wind power, due to the strong volatility of wind power, the output frequency of the power generation system of the offshore oil and gas field power grid will change in response to changes in wind power output. In order to ensure that the fluctuation of the output frequency of the power generation system of the offshore oil and gas field power grid is smoothed, it is necessary to determine the various output frequency indicators of the power generation system of the offshore oil and gas field when the output power of the wind turbine group changes, and then quantify these output frequency indicators to determine whether these output frequency indicators meet the operating requirements of the offshore oil and gas field power grid, and then modify the scheduling plan of the offshore oil and gas field power grid, such as modifying the start and stop status of the engine group in the offshore oil and gas field power grid, modifying the configuration parameters of the wind turbine group in the offshore oil and gas field power grid, and modifying the configuration parameters of the generator group in the offshore oil and gas field power grid.

[0057] There are two operating states for wind turbines connected to the offshore oil and gas field power grid: normal operating state and fault-off-grid state. In the normal operating state, the power supply of the wind turbine will fluctuate but will not disappear directly. In the fault-off-grid state, the power supply of the wind turbine will be disconnected from the grid, that is, it will not supply power to the offshore oil and gas field power grid.

[0058] The output frequency index includes the maximum frequency deviation when the wind turbine is in normal operation, and the maximum frequency deviation and steady-state frequency deviation when the wind turbine is in a fault-offline state. The specific calculation method and formula derivation process of these three output frequency indexes are explained below.

[0059] The generator set includes a synchronous generator, a prime mover, and a speed regulator. The rotor motion equation of the synchronous generator can be expressed as:

[0060] ;

[0061] in, represents the initial value of the mechanical power output of the prime mover of the power generation system, Indicates wind power output change information, Represents the load of the offshore oil and gas field power grid.

[0062] The speed governor of the generator set uses a PI controller to achieve differential and non-differential frequency regulation. Since the current offshore oil and gas field power grid generator sets all use digital speed governor controllers with millisecond response capabilities, the delay of the frequency regulation command can be ignored. The response process of the prime mover is described by the first-order inertia link. Therefore, the prime mover output power change model caused by frequency deviation can be expressed as:

[0063] .

[0064] In view of the two different states of offshore wind turbines during operation, wind power fluctuation models are built to simulate wind power fluctuations under normal conditions and power mutations when wind power is disconnected from the grid under fault conditions. Specifically,

[0065] When the wind turbine connected to the offshore oil and gas field power grid operates normally, due to the volatility of wind power, the output power fluctuation model of the wind turbine is:

[0066] .

[0067] When a wind turbine connected to the offshore oil and gas field power grid fails and goes offline, the output power fluctuation model of the wind turbine is:

[0068] .

[0069] in, represents the wind power output change information, Indicates the fluctuation ratio of wind power per unit time, represents the time constant of offshore wind power, represents the upper limit of wind power output power connected to the offshore oil and gas field power grid, represents the Laplace operator.

[0070] Based on the model given above, the frequency domain expression of the frequency change of the power generation system of the offshore oil and gas field power grid caused by fluctuations during normal operation of the wind turbine can be obtained as follows:

[0071] ;

[0072] .

[0073] Since the inertia time constant of the synchronous generator set and the prime mover time constant have negligible effects on the transient process of the frequency response, the frequency response model of the offshore oil and gas field power grid connected to wind power under normal operating conditions of the wind turbine set can be simplified as follows:

[0074] .

[0075] Based on the frequency domain expression of the frequency change of the offshore oil and gas field power grid power generation system under normal operation of the wind turbine, the maximum frequency deviation calculation formula of the power generation system when the wind turbine of the offshore oil and gas field power grid is operating normally can be obtained, that is, the output frequency index of the power generation system is determined based on the equivalent parameters and the operating parameters of the wind turbine connected to the offshore oil and gas field power grid, including:

[0076] The maximum frequency deviation of the wind turbine generator set when it is in normal operation is determined based on a first preset formula, and the first preset formula is:

[0077] ;

[0078] in, It indicates the maximum frequency deviation of the power generation system when the wind turbine is in normal operation. It represents the fluctuation ratio of wind power of wind turbines per unit time. , represents the governor proportional coefficient in the equivalent parameters of the power generation system, and D represents the damping coefficient in the equivalent parameters of the power generation system.

[0079] The frequency domain expression of the frequency change caused by the failure of the wind turbine to disconnect from the grid is:

[0080] ;

[0081] ;

[0082] ;

[0083] Transfer Function The damping ratio is: .

[0084] because Therefore, in actual operation, we can Approximately equal to D.

[0085] In offshore oil and gas fields, , , , can be obtained ,therefore, It is an underdamped system.

[0086] Based on the frequency domain expression of the frequency change of the wind turbine generator set in the offshore oil and gas field power grid when it is off-grid due to a fault, the maximum frequency deviation calculation formula of the power generation system when the wind turbine generator set is off-grid due to a fault can be obtained, that is, the output frequency index of the power generation system is determined based on the equivalent parameters and the operating parameters of the wind turbine generator set connected to the offshore oil and gas field power grid, including:

[0087] The maximum frequency deviation when the wind turbine generator set is in a grid-off fault state is determined based on a second preset formula, and the second preset formula is:

[0088] ;

[0089] ;

[0090] ;

[0091] ;

[0092] , ;

[0093] in, Indicates the maximum frequency deviation of the power generation system when the wind turbine is in a faulty and disconnected state. represents the upper limit of the output power of the wind turbine, H and D represent the inertia time constant and damping coefficient in the equivalent parameters of the power generation system respectively. represents the prime mover constant in the equivalent parameters of the power generation system, , Represents the governor proportional coefficient in the equivalent parameters of the power generation system, is the time when the frequency is at its lowest point.

[0094] When the wind turbine is in a fault-offline state, the steady-state frequency deviation expression of the power generation system is:

[0095] ;

[0096] in, It indicates the steady-state frequency deviation of the power generation system when the wind turbine is in a faulty and disconnected state.

[0097] According to the above-mentioned method for determining the frequency index, the frequency index value of the offshore oil and gas field platform during operation can be determined according to the operating parameters of the offshore oil and gas field platform, including the operating parameters of the wind turbine, the parameters of the generator set, and the start and stop status of the generator set, so as to determine whether the frequency index value corresponding to the operating parameters of the offshore oil and gas field platform can meet the requirements, and adjust the scheduling plan of the offshore oil and gas field platform, such as adjusting the start and stop status of the generator set and adjusting the parameters of the started generator set. That is to say, after determining the output frequency index of the power generation system based on the equivalent parameters and the operating parameters of the wind turbine connected to the offshore oil and gas field power grid, it includes:

[0098] Based on the output frequency index of the power generation system, the operation constraints of the power generation system are constructed.

[0099] The operation constraint condition can constrain the effectiveness of the scheduling scheme of the offshore oil and gas field power grid, that is, the scheduling scheme of the power generation system can be determined based on the operation constraint condition. Of course, it is understandable that the operation constraint condition can be constructed based on other indicators in addition to the output frequency indicator.

[0100] Specifically, considering the two operating conditions of wind turbines, the constraint condition of the impact of wind power uncertainty on the output frequency of the power generation system can be expressed as:

[0101] ;

[0102] ;

[0103] ;

[0104] In the formula, for The upper boundary of . for The upper boundary of . for The upper limit boundary can be set according to actual conditions.

[0105] From the front From the calculation formula, we can know that For H and A strong nonlinear function, for the convenience of scheduling, can be solved by using a commercial solver such as GUROBI, etc. In the method provided by the present invention, Transformed into H and The quadratic convex constraint is that based on the output frequency index of the power generation system, the operating constraints of the power generation system are constructed, including:

[0106] Construct a constraint function that the maximum frequency deviation of the wind turbine generator set when it is in a grid-off fault state is less than the maximum frequency deviation threshold;

[0107] The constraint condition function is transformed into a quadratic convex constraint function about the inertia time constant in the equivalent parameters of the power generation system and the prime mover constant in the equivalent parameters of the power generation system.

[0108] Will Transformed into H and The result of the quadratic convex constraint can be expressed as:

[0109] ;

[0110] in, , , , , , is the fitting parameter, which can be obtained by pre-fitting calculation.

[0111] The method provided by the present invention provides a frequency index quantification method during normal operation of offshore wind power and a step frequency index quantification method when offshore wind power is disconnected from the grid. At the same time, the constraint conditions of the two different operating conditions are integrally constructed, and finally the transfer function is converted into a quadratic convex model to adapt to conventional commercial solvers for solution operations.

[0112] In order to verify the correctness and effectiveness of the method provided by the present invention, the present invention takes a certain offshore oil and gas field as an example for verification. The system structure of the offshore oil and gas field is as follows: Figure 2 As shown in the figure, the offshore oil and gas field system consists of four interconnected offshore oil and gas platforms. Platform A1 and platform A2 form a production unit, and platform B1 and platform B2 form another production unit. The two production units are interconnected by a 15km cable to ensure the overall power supply reliability. The offshore oil and gas field is equipped with a gas compressor (C1) and two oil pumps (P1~P2) with a rated power. In order to meet the power supply demand, a total of 9 generator sets are configured, including two gas generator sets (G1~G2) and 7 fuel generator sets (G3~G9). The offshore wind turbine can be connected to the platform power grid through platform A1.

[0113] In a microgrid power system consisting of an offshore oil and gas platform with offshore wind power access, the speed regulators of all turbine generator sets are set with the same proportional coefficient. When KP=25, The fitting results are as follows Figure 3 shown. Figure 3 For the fitted surface and the original surface, and for different H and The fitting error when . Figure 4 is the distribution characteristic of the fitting error. It can be seen that 95% of the fitting errors are within 2.0% and 50% of the fitting errors are within 0.7%. Therefore, when KP=25, the distribution characteristics of H and A quadratic polynomial that can be used for nonlinear surfaces It has a good fitting effect.

[0114] When the governor proportional coefficient KP takes different values, The maximum fitting error is Figure 5 As shown. It can be seen that when the proportional coefficient of the speed regulator is different The maximum fitting error of does not exceed 3.23%. Therefore, for different speed regulator proportional coefficients, the The quadratic polynomial can be used for nonlinear surfaces Has a good fitting effect, such as Figure 5 shown.

[0115] The following is a description of the offshore oil and gas field power grid frequency index determination device applicable to wind power access provided by the present invention. The offshore oil and gas field power grid frequency index determination device applicable to wind power access described below and the offshore oil and gas field power grid frequency index determination method applicable to wind power access described above can be referred to each other. Figure 6 As shown, the device for determining frequency index of offshore oil and gas field power grid applicable to wind power access provided by the present invention comprises the following modules:

[0116] The equivalent parameter determination module 610 is used to determine the equivalent parameters of the power generation system according to the rated power, governor proportional coefficient, prime mover time constant, inertia time constant and damping coefficient of each generator set started in the power generation system of the offshore oil and gas field power grid, and the equivalent parameters include the governor proportional coefficient, prime mover time constant, inertia time constant and damping coefficient;

[0117] The frequency index determination module 620 is used to determine the output frequency index of the power generation system based on equivalent parameters and the operating parameters of the wind turbine group connected to the offshore oil and gas field power grid. The output frequency index includes the maximum frequency deviation when the wind turbine group is in normal operation, and the maximum frequency deviation and steady-state frequency deviation when the wind turbine group is in a faulty and disconnected state.

[0118] Figure 7 An example of a physical structure diagram of an electronic device is shown in FIG. Figure 7 As shown, the electronic device may include: a processor 710, a communication interface 720, a memory 730 and a communication bus 740, wherein the processor 710, the communication interface 720 and the memory 730 communicate with each other through the communication bus 740. The processor 710 may call the logic instructions in the memory 730 to execute a frequency index determination method for an offshore oil and gas field power grid suitable for wind power access, the method comprising: determining equivalent parameters of the power generation system according to the rated power, governor proportional coefficient, prime mover time constant, inertia time constant and damping coefficient of each generator set started in the power generation system of the offshore oil and gas field power grid, the equivalent parameters including governor proportional coefficient, prime mover time constant, inertia time constant and damping coefficient; determining the output frequency index of the power generation system based on the equivalent parameters and the operating parameters of the wind turbine set connected to the offshore oil and gas field power grid, the output frequency index including the maximum frequency deviation when the wind turbine set is in a normal operating state, and the maximum frequency deviation and steady-state frequency deviation when the wind turbine set is in a fault disconnected state.

[0119] In addition, the logic instructions in the above-mentioned memory 730 can be implemented in the form of a software functional unit and can be stored in a computer-readable storage medium when it is sold or used as an independent product. Based on this understanding, the technical solution of the present invention can be essentially or partly embodied in the form of a software product that contributes to the prior art. The computer software product is stored in a storage medium, including several instructions to enable a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk, etc. Various media that can store program codes.

[0120] On the other hand, the present invention also provides a computer program product, which includes a computer program, which can be stored on a non-transitory computer-readable storage medium. When the computer program is executed by a processor, the computer can execute the frequency index determination method for offshore oil and gas field power grids suitable for wind power access provided by the above methods, the method including: determining equivalent parameters of the power generation system according to the rated power, governor proportional coefficient, prime mover time constant, inertia time constant and damping coefficient of each generator set started in the power generation system of the offshore oil and gas field power grid, the equivalent parameters including the governor proportional coefficient, prime mover time constant, inertia time constant and damping coefficient; determining the output frequency index of the power generation system based on the equivalent parameters and the operating parameters of the wind turbine set connected to the offshore oil and gas field power grid, the output frequency index including the maximum frequency deviation when the wind turbine set is in normal operating state, and the maximum frequency deviation and steady-state frequency deviation when the wind turbine set is in a fault-offline state.

[0121] On the other hand, the present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, is implemented to execute the frequency index determination method for an offshore oil and gas field power grid suitable for wind power access provided by the above-mentioned methods, the method comprising: determining equivalent parameters of the power generation system according to the rated power, governor proportional coefficient, prime mover time constant, inertia time constant and damping coefficient of each generator set started in the power generation system of the offshore oil and gas field power grid, the equivalent parameters including the governor proportional coefficient, prime mover time constant, inertia time constant and damping coefficient; determining the output frequency index of the power generation system based on the equivalent parameters and the operating parameters of the wind turbine set connected to the offshore oil and gas field power grid, the output frequency index including the maximum frequency deviation when the wind turbine set is in normal operating state, and the maximum frequency deviation and steady-state frequency deviation when the wind turbine set is in a fault-off-grid state.

[0122] The device embodiments described above are merely illustrative, wherein the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the scheme of this embodiment. Ordinary technicians in this field can understand and implement it without paying creative labor.

[0123] Through the description of the above implementation methods, those skilled in the art can clearly understand that each implementation method can be implemented by means of software plus a necessary general hardware platform, and of course, can also be implemented by hardware. Based on this understanding, the above technical solution is essentially or the part that contributes to the prior art can be embodied in the form of a software product, and the computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, a disk, an optical disk, etc., including a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in each embodiment or some parts of the embodiments.

[0124] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for determining frequency index of offshore oil and gas field power grid suitable for wind power access, characterized in that: The method comprises: Determine equivalent parameters of the power generation system according to the rated power, governor proportional coefficient, prime mover time constant, inertia time constant and damping coefficient of each generator set started in the power generation system of the offshore oil and gas field power grid, wherein the equivalent parameters include the governor proportional coefficient, prime mover time constant, inertia time constant and damping coefficient; Determine the output frequency index of the power generation system based on the equivalent parameters and the operating parameters of the wind turbine generator set connected to the offshore oil and gas field power grid, wherein the output frequency index includes the maximum frequency deviation when the wind turbine generator set is in a normal operating state, and the maximum frequency deviation and steady-state frequency deviation when the wind turbine generator set is in a fault-offline state; The step of determining the output frequency index of the power generation system based on the equivalent parameter and the operating parameters of the wind turbine generator set connected to the offshore oil and gas field power grid includes: The maximum frequency deviation when the wind turbine generator set is in an off-grid fault state is determined based on a second preset formula, where the second preset formula is: Where Δf trip,nadir represents the maximum frequency deviation of the power generation system when the wind turbine is in a grid-off fault state, represents the upper limit of the output power of the wind turbine, H and D represent the inertia time constant and damping coefficient in the equivalent parameters of the power generation system respectively, T t represents the prime mover constant among the equivalent parameters of the power generation system, D eq =D+K P , K P It represents the governor proportional coefficient in the equivalent parameters of the power generation system.

2. The method for determining frequency index of offshore oil and gas field power grid suitable for wind power access according to claim 1 is characterized in that: The step of determining the output frequency index of the power generation system based on the equivalent parameter and the operating parameters of the wind turbine generator set connected to the offshore oil and gas field power grid includes: The maximum frequency deviation of the wind turbine generator set when it is in a normal operating state is determined based on a first preset formula, where the first preset formula is: Where Δf nor,nadir represents the maximum frequency deviation of the power generation system when the wind turbine is in normal operation, k WT It represents the fluctuation ratio of wind power of the wind turbine in unit time, D eq =D+K P , K P represents the governor proportional coefficient in the equivalent parameters of the power generation system, D represents the damping coefficient in the equivalent parameters of the power generation system, Indicates the output power upper limit of the wind turbine.

3. The method for determining frequency index of offshore oil and gas field power grid suitable for wind power access according to claim 1, characterized in that: The step of determining the output frequency index of the power generation system based on the equivalent parameter and the operating parameters of the wind turbine generator set connected to the offshore oil and gas field power grid includes: The steady-state frequency deviation of the wind turbine generator set when it is in a grid-off fault state is determined based on a third preset formula, wherein the third preset formula is: Where Δf trip,ess represents the steady-state frequency deviation of the power generation system when the wind turbine is in a grid-off fault state, represents the upper limit of the output power of the wind turbine, D eq =D+K P , K P represents the governor proportional coefficient in the equivalent parameters of the power generation system, and D represents the damping coefficient in the equivalent parameters of the power generation system.

4. The method for determining frequency index of offshore oil and gas field power grid suitable for wind power access according to claim 1, characterized in that: After determining the output frequency index of the power generation system based on the equivalent parameter and the operating parameters of the wind turbine generator set connected to the offshore oil and gas field power grid, the method includes: Based on the output frequency index of the power generation system, an operation constraint condition of the power generation system is constructed, and the operation constraint condition is used to adjust the scheduling plan of the offshore oil and gas field power grid.

5. The method for determining frequency index of offshore oil and gas field power grid applicable to wind power access according to claim 4 is characterized in that: The step of constructing the operation constraint condition of the power generation system based on the output frequency index of the power generation system includes: Constructing a constraint condition function that the maximum frequency deviation of the wind turbine generator set when it is in a grid-off fault state is less than a maximum frequency deviation threshold; The constraint condition function is converted into a quadratic convex constraint function about the inertia time constant in the equivalent parameters of the power generation system and the prime mover inter-constant in the equivalent parameters of the power generation system.

6. A device for determining frequency index of offshore oil and gas field power grid suitable for wind power access, characterized in that: The device comprises: An equivalent parameter determination module is used to determine the equivalent parameters of the power generation system according to the rated power, governor proportional coefficient, prime mover time constant, inertia time constant and damping coefficient of each generator set started in the power generation system of the offshore oil and gas field power grid, wherein the equivalent parameters include the governor proportional coefficient, prime mover time constant, inertia time constant and damping coefficient; A frequency index determination module, used to determine the output frequency index of the power generation system based on the equivalent parameters and the operating parameters of the wind turbine generator set connected to the offshore oil and gas field power grid, wherein the output frequency index includes a maximum frequency deviation and a steady-state frequency deviation; The step of determining the output frequency index of the power generation system based on the equivalent parameter and the operating parameters of the wind turbine generator set connected to the offshore oil and gas field power grid includes: The maximum frequency deviation when the wind turbine generator set is in an off-grid fault state is determined based on a second preset formula, where the second preset formula is: Where Δf trip,nadir represents the maximum frequency deviation of the power generation system when the wind turbine is in a grid-off fault state, represents the upper limit of the output power of the wind turbine, H and D represent the inertia time constant and damping coefficient in the equivalent parameters of the power generation system respectively, T t represents the prime mover constant among the equivalent parameters of the power generation system, D eq =D+K P , K P It represents the governor proportional coefficient in the equivalent parameters of the power generation system.

7. 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 computer program, the method for determining frequency indicators of offshore oil and gas field power grids applicable to wind power access as described in any one of claims 1 to 5 is implemented.

8. A non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the method for determining frequency index of an offshore oil and gas field power grid applicable to wind power access as claimed in any one of claims 1 to 5 is implemented.

9. A computer program product, comprising a computer program, characterized in that When the computer program is executed by a processor, the method for determining frequency index of an offshore oil and gas field power grid applicable to wind power access as claimed in any one of claims 1 to 5 is implemented.

Images