A pumped storage unit and wind power direct current sending operation simulation method and device

Abstract

The application discloses a pumped storage unit and wind power DC external transmission operation simulation method and device, comprising: obtaining operation simulation data, and performing standardization processing on the operation simulation data; the operation simulation data comprises wind power output data, load data, boundary condition data of the pumped storage unit and power transmission channel capacity; a pumped storage model is constructed according to pumped water power, power generation power, power and operation state of the pumped storage unit; the pumped storage unit comprises a constant-speed pumped storage unit and a variable-speed pumped storage unit; an optimization function is constructed according to external transmission power fluctuation and anti-peaking characteristics, the pumped storage model is optimized according to the optimization function to participate in wind power DC external transmission operation simulation, and an optimized operation simulation model is output; simulation is performed according to the optimized operation simulation model, and pumped storage unit and wind power DC external transmission power fluctuation and anti-peaking characteristic indexes are obtained.

Description

Technical Field

[0001] The present invention relates to the field of wind power technology, and in particular to a method and device for simulating the operation of a pumped storage unit and wind power direct current transmission. Background Art

[0002] As wind power accounts for an increasing proportion of power in the power grid, its inherently highly volatile and peak-shaving characteristics make stable grid operation increasingly challenging. Adopting flexible direct current (HVDC) transmission technology, combined with regulating resources like pumped hydroelectric storage, is an effective means of ensuring stable wind power transmission. HVDC flexible transmission technology allows for rapid and flexible adjustment of both active and reactive power. Pumped hydroelectric storage, as the most mature and energy-efficient energy storage technology, can pump water to store large amounts of energy during periods of high wind power generation and continuously discharge it during periods of low wind power generation, improving transmission channel utilization. Currently deployed pumped storage units in China mostly use DC-excited constant-speed synchronous generators. When operating in pumping mode, they can only draw power from the grid at a fixed power level. If power adjustment is required, pumped storage units can only operate at a few intermittent power points, limiting their flexibility. With technological advancements, variable-speed pumped storage units are gaining attention due to their performance advantages. Compared with fixed-speed units, variable-speed pumped-storage units can achieve continuous power adjustment in the pumping state, have more flexible adjustment characteristics, and can better promote the absorption and smooth transmission of wind power.

[0003] In the existing wind power and pumped storage operation simulation method, by assuming that all units in the pumped storage power station are variable-speed units, the wind power and pumped storage joint transmission operation simulation is performed, which easily leads to the pumped storage model not being in line with reality and the operation results being inaccurate; at the same time, the objective function in the current wind power and pumped storage joint transmission operation simulation optimization model ignores the impact of the transmission power fluctuation and anti-peak characteristics on the operation simulation. Summary of the Invention

[0004] The present invention provides a method and device for simulating the operation of a pumped-storage unit and wind power DC transmission, so as to solve the technical problem that the pumped-storage model in the existing wind power and pumped-storage operation simulation method does not include fixed-speed and variable-speed units, and ignores the influence of the transmission power fluctuation and anti-peak regulation characteristics on the operation simulation, resulting in poor operation simulation effect.

[0005] In order to solve the above technical problems, the present invention provides a method for simulating the operation of a pumped storage unit and wind power DC transmission, comprising:

[0006] Acquiring operation simulation data and performing per-unit normalization processing on the operation simulation data; the operation simulation data includes wind power output data, load data, boundary condition data of the pumped storage unit, and transmission channel capacity;

[0007] Constructing a pumped storage model based on the pumping power, generating power, electricity and operating status of the pumped storage unit; the pumped storage unit includes a fixed-speed pumped storage unit and a variable-speed pumped storage unit;

[0008] Constructing an optimization function based on the fluctuation and anti-peak regulation characteristics of the transmitted power, optimizing the pumped storage model participating in the wind power DC transmission operation simulation based on the optimization function, and outputting the optimized operation simulation model;

[0009] A simulation is performed based on the optimized operation simulation model to obtain the fluctuation and anti-peak regulation characteristic indicators of the pumped storage unit and the wind power direct current transmission power.

[0010] This invention establishes a pumped-storage model that includes both fixed-speed and variable-speed pumped-storage units to match the current realities of wind power and pumped-storage operations, resulting in more accurate results from combined wind power and pumped-storage simulations. Furthermore, a multi-objective optimization model for combined wind power and pumped-storage transmission simulations considers both the volatility of transmitted power and the anti-peaking characteristics of the system. This model assigns weights to each of these characteristics, transforming multiple objectives into a single objective. By optimizing these objectives, the transmitted power in the combined wind power and pumped-storage transmission simulations becomes more stable, further contributing to the safe and stable operation of the power system.

[0011] Furthermore, the operation simulation data is obtained and normalized, specifically:

[0012] Preset a reference value, and perform per-unit normalization processing on the wind power, load real value, pumped storage unit capacity, and DC transmission channel capacity of the operation simulation data according to the reference value;

[0013] Obtaining the maximum storable electricity of the pumped-storage power station according to the single-unit capacity, number of units, and maximum generating hours of the pumped-storage units;

[0014] A first external power transmission curve of the pumped storage unit is determined according to the wind power, pumped storage pumping power and power generation power of the operation simulation data.

[0015] Furthermore, the pumped storage model is constructed according to the pumping power, generating power, electricity and operating status of the pumped storage unit, specifically:

[0016] According to the pumping power of the pumped storage unit, the pumping condition constraints of the fixed-speed pumped storage unit and the variable-speed pumped storage unit are constructed respectively;

[0017] Establishing power generation operating condition constraints of the pumped storage unit according to the power generation power of the pumped storage unit;

[0018] Establishing an operating condition constraint according to the operating state of the pumped storage unit, wherein the operating state includes pumping and power generation;

[0019] Establishing a pumped storage power constraint according to the pumping efficiency and operating time of the pumped storage unit;

[0020] A pumped storage model is constructed according to the pumping condition constraints, power generation condition constraints, operation condition constraints and pumped storage power constraints.

[0021] Furthermore, the optimization function is constructed according to the fluctuation of the transmitted power and the anti-peak regulation characteristics, and the pumped storage model participating in the wind power DC transmission operation simulation is optimized according to the optimization function, and the optimized operation simulation model is output, specifically:

[0022] Obtaining a first external power curve, calculating a variance of the first external power curve, and determining a weight of external power volatility based on the variance;

[0023] Calculating a square sum of load operation errors according to the first external power curve, and determining a weight of an anti-peak regulation characteristic according to the square sum of load operation errors;

[0024] An optimization function is constructed according to the weight of the transmission power fluctuation and the weight of the anti-peak regulation characteristic, and the pumped storage model participating in the wind power direct current transmission operation simulation is optimized according to the optimization function, and the optimized operation simulation model is output.

[0025] Furthermore, the simulation is performed based on the optimized operation simulation model to obtain the volatility and anti-peak regulation characteristic indicators of the pumped storage unit and the wind power DC transmission power, specifically:

[0026] When performing simulation according to a preset cycle iteration, the external power of the running simulation model in the current cycle is calculated according to the first solver and the branch and bound method; the simulation is stopped until the preset condition is reached, and all external powers are output according to the simulation sequence;

[0027] A second external power curve is generated according to all the external powers, and the fluctuation and anti-peak regulation characteristic index of the external power are calculated according to the second external power curve.

[0028] In a second aspect, the present invention provides a pumped storage unit and wind power DC transmission operation simulation device, comprising a per-unit module, a model building module, a model optimization module and a simulation module;

[0029] The per-unit normalization module is used to obtain operation simulation data and perform per-unit normalization processing on the operation simulation data; the operation simulation data includes wind power output data, load data, boundary condition data of pumped storage units and transmission channel capacity;

[0030] The model building module is used to build a pumped storage model according to the pumping power, power generation power, power and operating status of the pumped storage unit; the pumped storage unit includes a fixed-speed pumped storage unit and a variable-speed pumped storage unit;

[0031] The model optimization module is used to construct an optimization function based on the fluctuation of the transmitted power and the anti-peak regulation characteristics, optimize the pumped storage model participating in the wind power direct current transmission operation simulation according to the optimization function, and output the optimized operation simulation model;

[0032] The simulation module is used to perform simulation according to the optimized operation simulation model to obtain the fluctuation and anti-peak characteristic indicators of the pumped storage unit and the wind power direct current transmission power.

[0033] Furthermore, the per-unit normalization module is specifically used to:

[0034] Preset a reference value, and perform per-unit normalization processing on the wind power, load real value, pumped storage unit capacity, and DC transmission channel capacity of the operation simulation data according to the reference value;

[0035] Obtaining the maximum storable electricity of the pumped-storage power station according to the single-unit capacity, number of units, and maximum generating hours of the pumped-storage units;

[0036] A first external power transmission curve of the pumped storage unit is determined according to the wind power, pumped storage pumping power and power generation power of the operation simulation data.

[0037] Furthermore, the model building module is specifically used to:

[0038] According to the pumping power of the pumped storage unit, the pumping condition constraints of the fixed-speed pumped storage unit and the variable-speed pumped storage unit are constructed respectively;

[0039] Establishing power generation operating condition constraints of the pumped storage unit according to the power generation power of the pumped storage unit;

[0040] Establishing an operating condition constraint according to the operating state of the pumped storage unit, wherein the operating state includes pumping and power generation;

[0041] Establishing a pumped storage power constraint according to the pumping efficiency and operating time of the pumped storage unit;

[0042] A pumped storage model is constructed according to the pumping condition constraints, power generation condition constraints, operation condition constraints and pumped storage power constraints.

[0043] Furthermore, the model optimization module is specifically used to:

[0044] Obtaining a first external power curve, calculating a variance of the first external power curve, and determining a weight of external power volatility based on the variance;

[0045] Calculating a square sum of load operation errors according to the first external power curve, and determining a weight of an anti-peak regulation characteristic according to the square sum of load operation errors;

[0046] An optimization function is constructed according to the weight of the transmission power fluctuation and the weight of the anti-peak regulation characteristic, and the pumped storage model participating in the wind power direct current transmission operation simulation is optimized according to the optimization function, and the optimized operation simulation model is output.

[0047] Furthermore, the simulation module is specifically used to:

[0048] When performing simulation according to a preset cycle iteration, the external power of the running simulation model in the current cycle is calculated according to the first solver and the branch and bound method; the simulation is stopped until the preset condition is reached, and all external powers are output according to the simulation sequence;

[0049] A second external power curve is generated according to all the external powers, and the fluctuation and anti-peak regulation characteristic index of the external power are calculated according to the second external power curve. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] Figure 1 A schematic flow chart of a method for simulating the operation of a pumped storage unit and wind power DC transmission provided in the first embodiment of the present invention;

[0051] Figure 2 Another flow chart of a method for simulating the operation of a pumped storage unit and wind power DC transmission provided in the first embodiment of the present invention;

[0052] Figure 3 A schematic structural diagram of a pumped storage unit and wind power DC transmission operation simulation device provided in the first embodiment of the present invention;

[0053] Figure 4 A topological diagram of wind power and pumped storage energy bundled and transmitted using flexible direct current transmission technology, provided in the first embodiment of the present invention;

[0054] Figure 5 A schematic diagram of a wind power and pumped storage combined transmission power curve provided in the second embodiment of the present invention;

[0055] Figure 6 A 24-hour pumped storage scheduling result diagram provided in the second embodiment of the present invention;

[0056] Figure 7Another schematic diagram of the wind power and pumped storage combined transmission power curve provided in the second embodiment of the present invention;

[0057] Figure 8 Another 24-hour pumped storage scheduling result diagram provided in the second embodiment of the present invention. DETAILED DESCRIPTION

[0058] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0059] Example 1

[0060] Please refer to Figure 1 , Figure 1 A flowchart of a method for simulating the operation of a pumped storage unit and wind power DC transmission provided by an embodiment of the present invention includes steps 101 to 104, which are specifically as follows:

[0061] Step 101: Acquire operation simulation data and perform per-unit normalization processing on the operation simulation; the operation simulation data includes wind power output data, load data, boundary condition data of the pumped storage unit, and transmission channel capacity;

[0062] In this embodiment, annual wind power output data, load data, boundary condition data of pumped-storage units, and capacity of DC transmission channels are collected on an hourly basis, and the data is normalized. The boundary condition data of the pumped-storage units mainly include single-unit capacity, number of units, maximum generating hours, maximum and minimum pumping and power generation, and pumping efficiency.

[0063] In this embodiment, the operation simulation data is obtained and normalized, specifically:

[0064] Preset a reference value, and perform per-unit normalization processing on the wind power, load real value, pumped storage unit capacity, and DC transmission channel capacity of the operation simulation data according to the reference value;

[0065] Obtaining the maximum storable electricity of the pumped-storage power station according to the single-unit capacity, number of units, and maximum generating hours of the pumped-storage units;

[0066] A first external power transmission curve of the pumped storage unit is determined according to the wind power, pumped storage pumping power and power generation power of the operation simulation data.

[0067] In this embodiment, the actual value of wind power is assumed to be P wind ', the true value of the load is P load ', the capacity of a single pumped storage unit is P storage ', the number of pumped storage units is n, the maximum generating hours of pumped storage is T Gen_max , the DC transmission channel capacity is P line ', the preset reference value is P B ,κ'={wind',load',storage',line'}.

[0068] In this embodiment, the wind power data P κ' Perform normalization processing, specifically:

[0069]

[0070] Among them, P κ The wind power data is normalized.

[0071] In this embodiment, the upper limit of the pumping and generating power of each pumped storage unit is P storage , the maximum storable electricity E of the pumped storage power station max , specifically:

[0072] E max =P storage ×n×T Gen_max (2)

[0073] In this embodiment, after the normalization process is completed, hourly-level timing production simulation and timing simulation are started with an hourly cycle.

[0074] In this embodiment, the operation strategy of pumped storage is that when wind power is high, pumped storage pumps water to absorb electricity, and when wind power is low, pumped storage releases water to generate electricity. Therefore, the power P of the combined wind power and pumped storage transmission power curve at time t is out (t), specifically:

[0075] P out (t) = P wind (t)+P Pump (t)-P Gen (t) (3)

[0076] Among them, P wind (t), P Pump (t), P Gen (t) represent the wind power, pumped storage pumping power and power generation power at time t, respectively.

[0077] Step 102: constructing a pumped storage model based on the pumping power, generating power, electricity, and operating status of the pumped storage unit; the pumped storage unit includes a fixed-speed pumped storage unit and a variable-speed pumped storage unit;

[0078] In this embodiment, a pumped storage model is established for simulating the combined transmission of wind power and pumped storage, including both fixed-speed pumped storage units and variable-speed pumped storage units. The model is constructed based on the pumping and power generation constraints of the pumped storage units, as well as the pumped storage power constraints.

[0079] Suppose there are n1 fixed-speed pumped-storage units and n2 variable-speed pumped-storage units, where n1 + n2 = n. The parameters of the fixed-speed units are identical, and the parameters of the variable-speed units are also identical. To simplify the model, the n1 fixed-speed units are treated as a single entity, and the n2 variable-speed units are treated as a single entity.

[0080] In this embodiment, the pumped storage model is constructed according to the pumping power, generating power, electricity and operating status of the pumped storage unit, specifically:

[0081] According to the pumping power of the pumped storage unit, the pumping condition constraints of the fixed-speed pumped storage unit and the variable-speed pumped storage unit are constructed respectively;

[0082] Establishing power generation operating condition constraints of the pumped storage unit according to the power generation power of the pumped storage unit;

[0083] Establishing an operating condition constraint according to the operating state of the pumped storage unit, wherein the operating state includes pumping and power generation;

[0084] Establishing a pumped storage power constraint according to the pumping efficiency and operating time of the pumped storage unit;

[0085] A pumped storage model is constructed according to the pumping condition constraints, power generation condition constraints, operation condition constraints and pumped storage power constraints.

[0086] In this embodiment, the pumping condition constraints include pumping condition constraints of a fixed-speed pumped-storage unit and a variable-speed pumped-storage unit.

[0087] In this embodiment, the fixed-speed pumped-storage unit can only operate at a fixed power point under pumping conditions, specifically 1.1 times the capacity of the pumped-storage unit. The pumping power is:

[0088] P constant_Pump (t) = num1 × P storage ×1.1,num1=0,1,2,...n1 (4)

[0089] Among them, Pconstant_Pump (t) represents the pumping power of the pumped-storage constant-speed unit at time t.

[0090] In this embodiment, the variable-speed pumped storage unit can achieve continuous adjustment from 0 to a maximum value under pumping conditions, and the maximum value is 1.1 times the capacity of the pumped storage unit. The pumping power is:

[0091] 0≤P change_Pump (t)≤n2×P storage ×1.1 (5)

[0092] Among them, P change_Pump (t) represents the pumping power of the pumped storage variable speed unit at time t.

[0093] In this embodiment, the pumping power P of the entire pumped storage power station at time t is Pump (t) Specifically:

[0094] P Pump (t) = P constant_Pump (t)+P change_Pump (t) (6)

[0095] In this embodiment, both fixed-speed and variable-speed pumped storage units can be continuously adjusted under power generation conditions. Therefore, there is no need to distinguish between fixed-speed units and variable-speed units under power generation conditions. The power generation condition constraint is:

[0096] 0≤P Gen (t)≤n×P storage (7)

[0097] In this embodiment, to ensure operational stability of the pumped-storage power station, pumping and generating cannot occur simultaneously. Therefore, not only can the same pumped-storage unit not be in both pumping and generating states at the same time, but also, as long as any unit in the pumped-storage power station is pumping, all units cannot be in generating state. Similarly, as long as any unit is generating, all units cannot be pumping. The operating condition constraints are:

[0098] P Pump (t)×P Gen (t)=0 (8)

[0099] In this embodiment, the pumped storage power station must ensure that the storage capacity of the reservoir does not exceed the maximum storage capacity at any time during operation. This model uses electricity instead of storage capacity. In addition, the pumped storage power station has losses during actual operation. Assume that the pumping efficiency of the pumped storage power station is η pumpTo ensure the smooth operation of the pumped storage power station, assuming that the pumped storage power station is regulated daily and the total operation simulation time T is an integer multiple of 24, the power consumption at the end of each day must be equal to the power consumption at the initial time. Therefore, the pumped storage power consumption constraint is:

[0100] 0≤E(t)≤E max (9)

[0101] E(t+1)=E(t)+P Pump (t)×η Pump -P Gen (t) (10)

[0102] E(0)=E(24)=E(48)=L=E(T) (11)

[0103] Among them, E(t) represents the amount of electricity stored in the pumped storage power station at time t, and E(0) represents the amount of electricity stored in the pumped storage power station at the initial moment.

[0104] Step 103: constructing an optimization function based on the fluctuation of the transmitted power and the anti-peak regulation characteristics, optimizing the pumped storage model participating in the wind power DC transmission operation simulation based on the optimization function, and outputting the optimized operation simulation model;

[0105] In this embodiment, an optimization function is constructed based on the fluctuation of the transmitted power and the anti-peak regulation characteristics, and the pumped storage model participating in the wind power DC transmission operation simulation is optimized according to the optimization function, and the optimized operation simulation model is output, specifically:

[0106] Obtaining a first external power curve, calculating a variance of the first external power curve, and determining a weight of external power volatility based on the variance;

[0107] Calculating a square sum of load operation errors according to the first external power curve, and determining a weight of an anti-peak regulation characteristic according to the square sum of load operation errors;

[0108] An optimization function is constructed according to the weight of the transmission power fluctuation and the weight of the anti-peak regulation characteristic, and the pumped storage model participating in the wind power direct current transmission operation simulation is optimized according to the optimization function, and the optimized operation simulation model is output.

[0109] In this embodiment, in order to establish a wind power and pumped storage combined transmission operation simulation optimization target that takes into account both the transmission power volatility and anti-peak shaving characteristics, mathematical models that can be used to represent the transmission power volatility and anti-peak shaving characteristics are first established.

[0110] In this embodiment, a volatility model is established based on the variance of the external power curve. Specifically:

[0111]

[0112]

[0113] Where min1 represents the variance of the outbound power, which is used to measure volatility; T represents the total time of the simulation; and average represents the average value of the outbound power curve.

[0114] In this embodiment, the higher the matching degree between the external power curve and the load, the smaller the impact of the external power curve on the system's anti-peak regulation. Therefore, the anti-peak regulation characteristic model is established based on the square sum of the errors when the external power curve follows the load. Specifically:

[0115]

[0116] Among them, min2 represents the square sum of the errors of the external power following the load operation, which is used to measure the anti-peak regulation characteristics; P load (t) represents the load power value at time t.

[0117] In this embodiment, a multi-objective optimization model for the combined wind power and pumped storage power transmission operation simulation is established with the goal of minimizing the variance min1 of the transmitted power and the sum of squared errors min2 of the transmitted power following the load. The optimization function is specifically:

[0118] min=w1×min1+w2×min2 (15)

[0119] Among them, min represents the optimization function of the optimization model; w1 represents the weight coefficient of volatility, and w2 represents the weight coefficient of anti-peak characteristics.

[0120] In this embodiment, the pumped storage model is optimized according to the optimization function to participate in the wind power DC transmission operation simulation, and the transmission power P at each moment is considered. out (t) Due to the capacity limitation of the DC transmission channel, a wind power and pumped storage combined transmission operation simulation optimization model with both fixed-speed and variable-speed pumped storage is established. The optimized operation simulation model is as follows:

[0121] min=w1×min1+w2×min2

[0122]

[0123] In this example, a multi-objective optimization model for the combined wind power and pumped hydro transmission operation simulation, taking into account both the fluctuation of transmission power and the anti-peak shaving characteristics, was established. The model weighted the fluctuation and anti-peak shaving characteristics, transforming the multi-objective model into a single objective. Under this optimization objective, the combined wind power and pumped hydro transmission simulation achieved more stable transmission power, contributing to the safe and stable operation of the power system.

[0124] Step 104: Perform simulation based on the optimized operation simulation model to obtain the fluctuation and anti-peak regulation characteristic indicators of the pumped storage unit and the wind power direct current transmission power.

[0125] In this embodiment, the simulation is performed based on the optimized operation simulation model to obtain the volatility and anti-peak regulation characteristic indicators of the pumped storage unit and the wind power DC transmission power, specifically:

[0126] When performing simulation according to a preset cycle iteration, the external power of the running simulation model in the current cycle is calculated according to the first solver and the branch and bound method; the simulation is stopped until the preset condition is reached, and all external powers are output according to the simulation sequence;

[0127] A second external power curve is generated according to all the external powers, and the fluctuation and anti-peak regulation characteristic index of the external power are calculated according to the second external power curve.

[0128] In this embodiment, hourly-level time series production simulation is performed with hourly periods, and the gurobi solver is used to solve the above-mentioned wind power and pumped storage combined transmission operation simulation optimization model. The method nested in the solver is the branch and bound method, which obtains the transmission power of the pumped storage model in each period until the full-year time series simulation is completed, outputs the transmission power of the simulation operation every hour, generates a second transmission power curve, and calculates the volatility and anti-peak characteristic index of the transmission power based on the second transmission power curve.

[0129] In this embodiment, the fluctuation and anti-peak characteristic index are calculated based on the obtained external power curve. Specifically, the fluctuation magnitude can be calculated using formulas (12) and (13).

[0130] In this embodiment, for the anti-peak regulation characteristics, it is necessary to calculate the peak-to-valley difference of the load and the peak-to-valley difference of the net load curve obtained after the wind power and pumped storage power are integrated into the receiving grid.

[0131] In this embodiment, the peak-to-valley difference of the load is first calculated. Specifically:

[0132] diff load =max(P load )-min(P load ) (17)

[0133] Among them, diff load Indicates the peak-to-valley difference of the load curve; max(P load ) represents the maximum value of the load curve; min(P load ) indicates the minimum value of the load.

[0134] Next, calculate the peak-to-valley difference of the net load curve. Specifically:

[0135] P equal_load =P load -P out (18)

[0136] diff equal_load =max(P equal_load )-min(P equal_load ) (19)

[0137] Among them, P equal_load Indicates the net load curve; diff equal_load Indicates the peak-to-valley difference of the net load curve; max(P equal_load ) represents the maximum value of the net load curve; min(P equal_load ) represents the minimum value of the net load curve.

[0138] In this embodiment, if diff equal_load Less than diff load , it means that the combined transmission of wind power and pumped storage has a better effect of following the receiving load; if diff equal_load Greater than diff load , indicating that the effect of the external power following the receiving end load is poor; if diff equal_load Equal to diff load , indicating that the transmission power curve is smooth and has no impact on the peak-to-valley differences in the receiving-end load. By comparing the fluctuation and anti-peak regulation characteristics of transmission power before and after optimization, we can analyze the role of pumped storage in improving the fluctuation and anti-peak regulation characteristics of combined wind power and pumped storage transmission power, and verify the ability of pumped storage to improve the stability of transmission power.

[0139] Please refer to Figure 2 , Figure 2 Another flow chart of a method for simulating the operation of a pumped storage unit and wind power DC transmission provided by an embodiment of the present invention.

[0140] In this example, hourly annual wind power output data, load data, boundary conditions for pumped-storage units (primarily including unit capacity, number of units, maximum generating hours, maximum and minimum pumping and generating power, and generation efficiency), and DC transmission channel capacity are collected and normalized. After normalization, hourly time-series production simulations are performed.

[0141] In this embodiment, in each simulation cycle, a model for combined wind power and pumped storage transmission operation simulation, including both fixed-speed and variable-speed units, is established, defined as a pumped storage model. An optimization objective for the combined wind power and pumped storage transmission operation simulation is established, taking into account both transmission power fluctuation and anti-peak shaving characteristics. Next, based on the established pumped storage model and the operation simulation optimization objective, an optimization model for combined wind power and pumped storage transmission operation simulation, including both fixed-speed and variable-speed pumped storage, is established. Subsequently, the optimization model is solved using a Gurobi solver, employing a branch-and-bound nested solution method. The transmission power of the pumped storage model for each simulation cycle is output until the full-year time series simulation is completed. A transmission power curve is generated based on the transmission power of each hour of the simulation operation. The transmission power fluctuation and anti-peak shaving characteristics are calculated based on the transmission power curve, and the transmission power fluctuation and anti-peak shaving characteristics indicators are analyzed.

[0142] Please refer to Figure 3 , Figure 3 A schematic structural diagram of a pumped storage unit and wind power DC transmission operation simulation device provided by an embodiment of the present invention, comprising a normalization module 301, a model construction module 302, a model optimization module 303, and a simulation module 304;

[0143] The per-unit normalization module 301 is used to obtain operation simulation data and perform per-unit normalization processing on the operation simulation data; the operation simulation data includes wind power output data, load data, boundary condition data of pumped storage units and transmission channel capacity;

[0144] The model building module 302 is used to build a pumped storage model based on the pumping power, power generation power, power and operating status of the pumped storage unit; the pumped storage unit includes a fixed-speed pumped storage unit and a variable-speed pumped storage unit;

[0145] The model optimization module 303 is used to construct an optimization function based on the fluctuation of the transmitted power and the anti-peak regulation characteristics, optimize the pumped storage model participating in the wind power DC transmission operation simulation according to the optimization function, and output the optimized operation simulation model;

[0146] The simulation module 304 is used to perform simulation according to the optimized operation simulation model to obtain the fluctuation and anti-peak characteristic indicators of the pumped storage unit and the wind power direct current transmission power.

[0147] In this embodiment, the per-unit normalization module is specifically used to:

[0148] Preset a reference value, and perform per-unit normalization processing on the wind power, load real value, pumped storage unit capacity, and DC transmission channel capacity of the operation simulation data according to the reference value;

[0149] Obtaining the maximum storable electricity of the pumped-storage power station according to the single-unit capacity, number of units, and maximum generating hours of the pumped-storage units;

[0150] A first external power transmission curve of the pumped storage unit is determined according to the wind power, pumped storage pumping power and power generation power of the operation simulation data.

[0151] In this embodiment, the model building module is specifically used to:

[0152] According to the pumping power of the pumped storage unit, the pumping condition constraints of the fixed-speed pumped storage unit and the variable-speed pumped storage unit are constructed respectively;

[0153] Establishing power generation operating condition constraints of the pumped storage unit according to the power generation power of the pumped storage unit;

[0154] Establishing an operating condition constraint according to the operating state of the pumped storage unit, wherein the operating state includes pumping and power generation;

[0155] Establishing a pumped storage power constraint according to the pumping efficiency and operating time of the pumped storage unit;

[0156] A pumped storage model is constructed according to the pumping condition constraints, power generation condition constraints, operation condition constraints and pumped storage power constraints.

[0157] In this embodiment, the model optimization module is specifically used to:

[0158] Obtaining a first external power curve, calculating a variance of the first external power curve, and determining a weight of external power volatility based on the variance;

[0159] Calculating a square sum of load operation errors according to the first external power curve, and determining a weight of an anti-peak regulation characteristic according to the square sum of load operation errors;

[0160] An optimization function is constructed according to the weight of the transmission power fluctuation and the weight of the anti-peak regulation characteristic, and the pumped storage model participating in the wind power direct current transmission operation simulation is optimized according to the optimization function, and the optimized operation simulation model is output.

[0161] In this embodiment, the simulation module is specifically used to:

[0162] When performing simulation according to a preset cycle iteration, the external power of the running simulation model in the current cycle is calculated according to the first solver and the branch and bound method; the simulation is stopped until the preset condition is reached, and all external powers are output according to the simulation sequence;

[0163] A second external power curve is generated according to all the external powers, and the fluctuation and anti-peak regulation characteristic index of the external power are calculated according to the second external power curve.

[0164] In this embodiment, by establishing a pumped storage model that includes both fixed-speed and variable-speed pumped storage units to match the current realities of wind power and pumped storage, the results of the wind power and pumped storage combined operation simulation are more accurate. Furthermore, a multi-objective optimization model for the wind power and pumped storage combined transmission operation simulation, which considers both the fluctuation of transmitted power and the anti-peaking characteristics, assigns weights to the fluctuation and anti-peaking characteristics, transforming the multi-objective model into a single objective. By optimizing these objectives, the transmitted power of the wind power and pumped storage combined transmission operation simulation is stabilized, further contributing to the safe and stable operation of the power system.

[0165] Example 2

[0166] Please refer to Figure 4 , Figure 4 A topological structure diagram of offshore wind power and pumped storage bundled and transmitted using flexible direct current transmission technology provided in an embodiment of the present invention.

[0167] In this example, the offshore wind farm consists of three 2-megawatt sites, connected via an onshore switchyard. The pumped storage system consists of four turbines, three fixed-speed and one variable-speed. Each turbine has a capacity of 300,000 kilowatts, and the maximum pumping power of a single pumped storage unit is 1.1 x 300,000 kilowatts = 330,000 kilowatts. The pumped storage station can generate a maximum power of 1.2 million kilowatts for seven hours, with an initial power output of 0.2 x 1.2 million kilowatts x 7 hours = 1.68 million kWh. The pumping efficiency is set at 0.75. The capacity of the HVDC Flexible transmission channel is 6 million kilowatts.

[0168] In this embodiment, the operation simulation calculation of offshore wind power and pumped storage is carried out by taking 24 hours as an example, and two extreme scenarios are set, namely w1=1, w2=0 (only considering volatility) and w1=0, w2=1 (only considering anti-peak characteristics).

[0169] In this embodiment, when only the volatility is considered, the combined transmission power curve of offshore wind power and pumped storage is as follows: Figure 5As shown in the figure, the 24-hour pumped storage scheduling results are as follows: Figure 6 As shown;

[0170] In this embodiment, Figure 5 and Figure 6 As can be seen, offshore wind power has significant intraday volatility, with peak generation between 1:00 AM and 3:00 PM, and low generation between 4:00 PM and 12:00 AM. During periods of high offshore wind power generation, pumped hydro absorbs excess electricity by pumping water, while during periods of low offshore wind power generation, pumped hydro fills the power gap by releasing water, thereby reducing the volatility of offshore wind power. Figure 5 The results show that through peak shaving and valley filling of pumped storage, the output power is almost a straight line with good stability.

[0171] In this embodiment, when only the peak load regulation characteristic is used, the combined transmission power curve of offshore wind power and pumped storage is as follows: Figure 7 As shown in the figure, the 24-hour pumped storage scheduling results are as follows: Figure 8 shown.

[0172] In this embodiment, Figure 7 and Figure 8 It can be seen that offshore wind power exhibits obvious anti-peak characteristics, which is extremely detrimental to the stable operation of the system. Through the operation and scheduling of pumped storage, the combined transmission power curve of offshore wind power and pumped storage can be better realized to follow the load curve, which greatly weakens the impact of offshore wind power anti-peak. In addition, Figure 6 and 8 It can be seen that since the variable speed unit is taken into account in the model, the adjustment range of pumped storage under pumping conditions is wider and is no longer limited to a few discrete points, which makes it more flexible.

[0173] The specific embodiments described above further illustrate the objectives, technical solutions, and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the scope of protection of the present invention. In particular, it should be noted that any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included within the scope of protection of the present invention for those skilled in the art.

Claims

1. A method for simulating the operation of a pumped storage unit and wind power DC transmission, characterized in that: include: Acquiring operation simulation data and performing normalization processing on the operation simulation data; The operation simulation data includes wind power output data, load data, boundary condition data of pumped storage units and transmission channel capacity; Constructing a pumped storage model based on the pumping power, generating power, electricity and operating status of the pumped storage unit; the pumped storage unit includes a fixed-speed pumped storage unit and a variable-speed pumped storage unit; An optimization function is constructed based on the fluctuation and anti-peak regulation characteristics of the transmitted power. The pumped storage model participating in the wind power DC transmission operation simulation is optimized based on the optimization function, and the optimized operation simulation model is output. The pumped storage model participating in the wind power DC transmission operation simulation is optimized based on the optimization function, and considering that the transmitted power at each moment is limited by the capacity of the DC transmission channel, a wind power and pumped storage combined transmission operation simulation optimization model including both fixed-speed and variable-speed pumped storage is established. The optimized operation simulation model is specifically as follows: Among them, min represents the optimization function of the optimization model; w1 represents the weight coefficient of volatility, w2 represents the weight coefficient of anti-peak regulation characteristics, min1 is the variance of the external power, min2 is the sum of squares of the error of the external power following the load operation, P change_Pump (t) represents the pumping power of the pumped storage variable speed unit at time t, P constant_Pump (t) is the pumping power of the pumped storage constant speed unit at time t, P storage is the capacity of the pumped storage unit, num1 is the gear coefficient of the fixed-speed unit, n1 is the number of fixed-speed units, n2 is the speed of the variable-speed unit, n is the total number of units, P Gen (t) is the power generation capacity of the pumped storage unit, E max is the maximum storable electricity of the pumped storage power station, T Gen_max is the maximum power generation hours, P out (t) is the power sent out, P wind (t) is the wind power output, E(t) is the amount of electricity stored in the pumped storage power station at time t, E(0) is the amount of electricity stored in the pumped storage power station at the initial time, P line is the capacity of the DC transmission channel; A simulation is performed based on the optimized operation simulation model to obtain the fluctuation and anti-peak regulation characteristic indicators of the pumped storage unit and the wind power direct current transmission power.

2. The method for simulating the operation of a pumped storage unit and wind power DC transmission according to claim 1, characterized in that: The obtaining of the operation simulation data and normalization of the operation simulation data are specifically as follows: Preset a reference value, and perform per-unit normalization processing on the wind power, load real value, pumped storage unit capacity, and DC transmission channel capacity of the operation simulation data according to the reference value; Obtaining the maximum storable electricity of the pumped-storage power station according to the single-unit capacity, number of units, and maximum generating hours of the pumped-storage units; A first external power transmission curve of the pumped storage unit is determined according to the wind power, pumped storage pumping power and power generation power of the operation simulation data.

3. The method for simulating the operation of a pumped storage unit and wind power DC transmission according to claim 1, characterized in that: The pumped storage model is constructed according to the pumping power, generating power, electricity and operating status of the pumped storage unit, specifically: According to the pumping power of the pumped storage unit, the pumping condition constraints of the fixed-speed pumped storage unit and the variable-speed pumped storage unit are constructed respectively; Establishing power generation operating condition constraints of the pumped storage unit according to the power generation power of the pumped storage unit; Establishing an operating condition constraint according to the operating state of the pumped storage unit, wherein the operating state includes pumping and power generation; Establishing a pumped storage power constraint according to the pumping efficiency and operating time of the pumped storage unit; A pumped storage model is constructed according to the pumping condition constraints, power generation condition constraints, operation condition constraints and pumped storage power constraints.

4. A method for simulating operation of a pumped storage unit and wind power DC transmission according to any one of claims 1 to 3, characterized in that: The optimization function is constructed according to the fluctuation of the transmitted power and the anti-peak regulation characteristics, the pumped storage model is optimized according to the optimization function for participating in the wind power direct current transmission operation simulation, and the optimized operation simulation model is output, specifically: Obtaining a first external power curve, calculating a variance of the first external power curve, and determining a weight of external power volatility based on the variance; Calculating a square sum of load operation errors according to the first external power curve, and determining a weight of an anti-peak regulation characteristic according to the square sum of load operation errors; An optimization function is constructed according to the weight of the transmission power fluctuation and the weight of the anti-peak regulation characteristic, and the pumped storage model participating in the wind power direct current transmission operation simulation is optimized according to the optimization function, and the optimized operation simulation model is output.

5. The method for simulating the operation of a pumped storage unit and wind power DC transmission according to claim 1, characterized in that: The simulation is performed based on the optimized operation simulation model to obtain the fluctuation and anti-peak regulation characteristic indicators of the pumped storage unit and the wind power DC transmission power, specifically: When performing simulation according to a preset cycle iteration, the external power of the running simulation model in the current cycle is calculated according to the first solver and the branch and bound method; the simulation is stopped until the preset condition is reached, and all external powers are output according to the simulation sequence; A second external power curve is generated according to all the external powers, and the fluctuation and anti-peak regulation characteristic index of the external power are calculated according to the second external power curve.

6. A pumped storage unit and wind power DC transmission operation simulation device, characterized in that: Including normalization module, model building module, model optimization module and simulation module; The per-unit normalization module is used to obtain operation simulation data and perform per-unit normalization processing on the operation simulation data; the operation simulation data includes wind power output data, load data, boundary condition data of pumped storage units and transmission channel capacity; The model building module is used to build a pumped storage model according to the pumping power, power generation power, power and operating status of the pumped storage unit; the pumped storage unit includes a fixed-speed pumped storage unit and a variable-speed pumped storage unit; The model optimization module is used to construct an optimization function based on the fluctuation and anti-peak regulation characteristics of the transmitted power, optimize the pumped storage model participating in the wind power DC transmission operation simulation according to the optimization function, and output the optimized operation simulation model; optimize the pumped storage model participating in the wind power DC transmission operation simulation according to the optimization function, and consider that the transmitted power at each moment is limited by the capacity of the DC transmission channel, to establish a wind power and pumped storage combined transmission operation simulation optimization model that includes both fixed-speed and variable-speed pumped storage. The optimized operation simulation model is specifically: Among them, min represents the optimization function of the optimization model; w1 represents the weight coefficient of volatility, w2 represents the weight coefficient of anti-peak regulation characteristics, min1 is the variance of the external power, min2 is the sum of squares of the error of the external power following the load operation, represents the pumping power of the pumped storage variable speed unit at time t, P constant_Pump (t) is the pumping power of the pumped storage constant speed unit at time t, P storage is the capacity of the pumped storage unit, num1 is the gear coefficient of the fixed-speed unit, n1 is the number of fixed-speed units, n2 is the speed of the variable-speed unit, n is the total number of units, P Gen (t) is the power generation capacity of the pumped storage unit, E max is the maximum storable electricity of the pumped storage power station, T Gen_max is the maximum power generation hours, P out (t) is the power sent out, P wind (t) is the wind power output, E(t) is the amount of electricity stored in the pumped storage power station at time t, E(0) is the amount of electricity stored in the pumped storage power station at the initial time, P line is the capacity of the DC transmission channel; The simulation module is used to perform simulation according to the optimized operation simulation model to obtain the fluctuation and anti-peak characteristic indicators of the pumped storage unit and the wind power direct current transmission power.

7. The pumped storage unit and wind power DC transmission operation simulation device according to claim 6, characterized in that: The per-unit normalization module is specifically used for: Preset a reference value, and perform per-unit normalization processing on the wind power, load real value, pumped storage unit capacity, and DC transmission channel capacity of the operation simulation data according to the reference value; Obtaining the maximum storable electricity of the pumped-storage power station according to the single-unit capacity, number of units, and maximum generating hours of the pumped-storage units; A first external power transmission curve of the pumped storage unit is determined according to the wind power, pumped storage pumping power and power generation power of the operation simulation data.

8. The pumped storage unit and wind power DC transmission operation simulation device according to claim 6, characterized in that: The model building module is specifically used to: According to the pumping power of the pumped storage unit, the pumping condition constraints of the fixed-speed pumped storage unit and the variable-speed pumped storage unit are constructed respectively; Establishing power generation operating condition constraints of the pumped storage unit according to the power generation power of the pumped storage unit; Establishing an operating condition constraint according to the operating state of the pumped storage unit, wherein the operating state includes pumping and power generation; Establishing a pumped storage power constraint according to the pumping efficiency and operating time of the pumped storage unit; A pumped storage model is constructed according to the pumping condition constraints, power generation condition constraints, operation condition constraints and pumped storage power constraints.

9. A pumped storage unit and wind power direct current transmission operation simulation device according to any one of claims 6 to 8, characterized in that: The model optimization module is specifically used to: Obtaining a first external power curve, calculating a variance of the first external power curve, and determining a weight of external power volatility based on the variance; Calculating a square sum of load operation errors according to the first external power curve, and determining a weight of an anti-peak regulation characteristic according to the square sum of load operation errors; An optimization function is constructed according to the weight of the transmission power fluctuation and the weight of the anti-peak regulation characteristic, and the pumped storage model participating in the wind power direct current transmission operation simulation is optimized according to the optimization function, and the optimized operation simulation model is output.

10. The pumped storage unit and wind power DC transmission operation simulation device according to claim 6, characterized in that: The simulation module is specifically used for: When performing simulation according to a preset cycle iteration, the external power of the running simulation model in the current cycle is calculated according to the first solver and the branch and bound method; the simulation is stopped until the preset condition is reached, and all external powers are output according to the simulation sequence; A second external power curve is generated according to all the external powers, and the fluctuation and anti-peak regulation characteristic index of the external power are calculated according to the second external power curve.

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