Optimal dispatching method, device, equipment and medium considering the output of renewable energy

Abstract

The present invention relates to the technical field of optimized dispatching of power transmission from a new energy base, and in particular to an optimized dispatching method, device, equipment and medium considering power transmission from new energy bases. The method includes: establishing a joint peak-shaving dispatching strategy of pumped storage and thermal power; establishing a hierarchical optimization dispatching strategy according to the joint peak-shaving dispatching strategy, wherein the upper layer of the hierarchical optimization dispatching strategy takes the minimum volatility of the base transmission curve as the objective function, and establishes dispatching constraints based on the operating characteristics of the pumped storage unit; the lower layer takes the maximum wind and solar output of the base as the objective function, and considers dispatching constraints based on the stability of DC transmission and the stability of the operation of the power grid at the sending end; estimates the frequency safety margin through linear constraints, and establishes a hierarchical optimization dispatching model based on the objective function and constraints in the hierarchical optimization dispatching strategy; solves the hierarchical optimization dispatching model to obtain an optimized dispatching method. In the present invention, the utilization of wind and solar power resources is maximized, while ensuring the safe and stable operation of the power grid.

Description

Technical Field

[0001] The present invention relates to the technical field of optimized dispatching of external output of a new energy base, and in particular to an optimized dispatching method, device, equipment and medium considering external output of new energy. Background Art

[0002] With the rapid development of large-scale new energy bases in the Shagohuang area, the insufficient local consumption level and insufficient access space for existing channels have led to the key restriction of new transmission channels. After the large-scale grid connection of wind power and photovoltaic power, its randomness and volatility have greatly increased the difficulty of safe and stable operation of the power grid. As an important tool for peak load regulation and frequency regulation of the power grid, hydropower stations can use their rapid regulation to reduce the negative impact of wind power grid connection on the power system.

[0003] In recent years, domestic and foreign scholars have conducted some research on the joint dispatch of pumped storage power stations and wind and solar power, but multi-beam research has failed to consider the coordinated operation of pumped storage and thermal power as supporting power sources and wind and solar power. In order to ensure the safe, stable and economical operation of the power supply at the sending and receiving ends, the coordinated cooperation of multiple power sources is required. In addition, the existing studies have simplified the modeling of pumped storage power stations, and have given less consideration to the hydraulic constraints of pumped storage power stations and the impact of water head on the power generation and pumping characteristics of the units, resulting in the inability to accurately simulate the output plan of pumped storage power stations, making it difficult to give full play to the regulating role of pumped storage power stations on wind power.

[0004] Therefore, it is of great significance to use pumped storage to replace coal-fired power as a supporting power source, analyze the changes in the safe and stable support capacity of large-scale wind power and photovoltaic bases through the UHV DC transmission system, and study the impact performance of pumped storage replacing coal-fired power.

[0005] The information disclosed in this background technology section is only intended to deepen the understanding of the overall background technology of the present invention, and should not be regarded as acknowledging or suggesting in any form that the information constitutes the prior art already known to those skilled in the art. Summary of the invention

[0006] The present invention provides an optimization scheduling method, device, equipment and medium taking into account the output of new energy transmission, thereby effectively solving the problems in the background technology.

[0007] In order to achieve the above object, the technical solution adopted by the present invention is: an optimization scheduling method considering the output of new energy transmission, comprising:

[0008] Establish a joint peak-shaving dispatching strategy for pumped storage and thermal power;

[0009] A hierarchical optimization scheduling strategy is established according to the joint peak-shaving scheduling strategy. The upper layer of the hierarchical optimization scheduling strategy takes the minimum volatility of the base transmission curve as the objective function and establishes scheduling constraints based on the operating characteristics of the pumped storage unit; the lower layer takes the maximum output of the base wind and solar power as the objective function and considers the scheduling constraints of the DC transmission stability and the operation stability of the sending-end power grid;

[0010] The frequency safety margin is estimated by linear constraints, and a hierarchical optimization scheduling model is established based on the objective function and constraint conditions in the hierarchical optimization scheduling strategy;

[0011] The hierarchical optimization scheduling model is solved to obtain an optimization scheduling method.

[0012] Furthermore, the establishment of a joint peak-shaving dispatching strategy of pumped storage and thermal power includes:

[0013] Consider using pumped storage to smooth the volatility of the power transmission curve of the new energy base: when the power transmission of the new energy base exceeds the upper limit of the power transmission channel capacity, the pumped storage unit will pump water to absorb excess wind and solar power output, reducing the number and depth of deep peak regulation of thermal power units; when the power transmission of the new energy base is lower than the lower limit of the power transmission channel capacity, the pumped storage unit will coordinate power generation with the thermal power unit to reduce the peak pressure of the thermal power unit.

[0014] Furthermore, the objective function of the hierarchical optimization scheduling strategy includes:

[0015] Upper objective function:

[0016] ;

[0017] In the formula, for DC transmission power during the period;

[0018] The lower objective function is:

[0019] ;

[0020] In the formula, is the total electricity generated by wind power and photovoltaic power; is the number of time periods in the scheduling cycle; and Wind power and photovoltaic power generation Output during the period.

[0021] Furthermore, the upper-level scheduling constraints in the hierarchical optimization scheduling strategy include:

[0022] Pumped storage power station capacity constraints:

[0023] ;

[0024] In the formula, for The amount of water stored in the reservoir during the period; and are the minimum and maximum storage capacities of the upper reservoir, respectively; and They are Time period The flow rate of the pumped storage unit under power generation and pumping conditions; It is the water level control target of the upper reservoir at the end of the period; is the number of pumped storage units;

[0025] Power constraints of pumped storage units:

[0026] ;

[0027] ;

[0028] In the formula, , Respectively The minimum and maximum output values ​​of the pumped storage units under power generation conditions; For the The maximum output of a pumped storage unit under pumping conditions;

[0029] Output / water conversion efficiency constraints of pumped storage power stations:

[0030] ;

[0031] In the formula, , Respectively The power generation and pumping efficiency of the pumped storage units; The maximum water discharge volume under power generation state; It is the minimum water discharge volume under power generation status; It is the maximum pumping volume under pumping state.

[0032] Furthermore, the lower-level scheduling constraints considering the stability of DC transmission in the hierarchical optimization scheduling strategy include:

[0033] Sending end system stability constraints:

[0034] A simple wind power and photovoltaic base sending-end system is difficult to operate stably, and requires the coordinated operation of thermal power units, pumped storage units and wind power and photovoltaic units. That is, the number of thermal power units and pumped storage units in operation in each period must be guaranteed to a certain extent:

[0035] ;

[0036] Where: For the Thermal power units The operating status of the time period; for Time period The operating status of the pumped storage units under power generation conditions; for Time period The pumped storage unit is operating under pumping conditions; is the number of thermal power units; is the number of pumped storage units; The minimum number of thermal power units and pumped storage units that need to be started in each period.

[0037] Furthermore, the lower-level scheduling constraints that consider the stability of the sending-end power grid operation in the hierarchical optimization scheduling strategy include:

[0038] DC constant operation time constraints:

[0039] ;

[0040] ;

[0041] ;

[0042] In the formula, is a 0-1 variable indicating Whether the DC power is adjusted during the time period; Indicates the minimum DC constant operating time;

[0043] Voltage stability constraints:

[0044] ;

[0045] In the formula, is the voltage stability margin; is the total active power of the load under critical state; is the total active power of the load in the initial operating state; is the minimum stability margin, and its value range is 0~1;

[0046] Frequency safety constraints:

[0047] ;

[0048] ;

[0049] In the formula, is the frequency safety margin; is the initial frequency of the system; is the system frequency safety threshold; is the system equivalent inertia constant; are turbine parameters; is the speed regulator adjustment constant; Determined by the maximum disturbance, such as the maximum output of a thermal power unit;

[0050] Frequency response constraints of thermal power units:

[0051] ;

[0052] In the formula, For the A binary variable indicating whether the thermal power unit participates in the primary frequency response; For the A binary variable for the start and stop status of a thermal power unit;

[0053] Output constraints of thermal power units:

[0054] ;

[0055] In the formula, and Respectively The minimum and maximum output of each thermal power unit; express Thermal power units The operating status of

[0056] Wind power and photovoltaic output constraints:

[0057] ;

[0058] In the formula, and Wind power and photovoltaic power The maximum predicted output for the time period;

[0059] Grid support power constraints:

[0060] ;

[0061] ;

[0062] In the formula, for The grid support power during the period; for DC transmission power during the period; is the grid support factor, which is defined as the ratio of the grid support power ceiling to the DC transmission planned power; The number of calculation period periods for supporting balancing constraints for the power grid;

[0063] DC transmission channel capacity constraints:

[0064] ;

[0065] In the formula, for DC transmission power during the period; and for Wind power and photovoltaic output during the time period; for Output of thermal power units during the period; for Power generation capacity of pumped storage units during period; for Pumping power of pumped storage units during the period; for The grid support power during the period; It is the upper limit of DC channel transmission capacity.

[0066] Furthermore, in the estimation of the frequency safety margin by linear constraints, the parameter , , The frequency safety margin is estimated based on the constraints of

[0067] ;

[0068] ;

[0069] ;

[0070] In the formula, , , They are the predicted power generation of wind farms, photovoltaic power plants, and load demand; For the A binary variable for the start and stop status of a thermal power unit; No. Inertia constant of thermal power units; For the The maximum output of the thermal power units; , , Respectively A binary variable indicating whether a thermal power unit, wind farm, or photovoltaic power station participates in the primary frequency response; and are the comprehensive inertia constants of wind farm and photovoltaic power station respectively; For the Mechanical power gain coefficient of thermal power units; For the The proportion of electricity generated by high-pressure turbines in thermal power plants; For the The speed governor adjustment constant of each thermal power unit; and are the droop coefficients of wind farms and photovoltaic power plants, respectively;

[0071] The output space of the response unit is reserved to provide a primary frequency response, satisfying the following constraints:

[0072] ;

[0073] ;

[0074] ;

[0075] In the formula, the lowest frequency point Greater than the quasi-steady-state frequency; parameter The value of is less than 1.

[0076] Furthermore, solving the hierarchical optimization scheduling model includes:

[0077] The hierarchical optimization scheduling model is solved by calling the Gurobi solver using Yalmip to obtain the active output of thermal power units, wind farms, photovoltaic power stations, pumped storage power stations and other power grid support at each moment, thereby obtaining the output of the new energy base.

[0078] The present invention also includes an optimization scheduling device considering the output of renewable energy, using the above method, including:

[0079] Joint peak-shaving dispatching unit, used to establish a joint peak-shaving dispatching strategy for pumped storage and thermal power;

[0080] A hierarchical optimization dispatching unit is used to establish a hierarchical optimization dispatching strategy according to the joint peak-shaving dispatching strategy. The upper layer of the hierarchical optimization dispatching strategy takes the minimum volatility of the base transmission curve as the objective function and establishes dispatching constraints based on the operating characteristics of the pumped storage unit; the lower layer takes the maximum output of the base wind and solar power as the objective function and considers the dispatching constraints of the DC transmission stability and the operation stability of the sending-end power grid;

[0081] A modeling unit, used to estimate the frequency safety margin through linear constraints, and establish a hierarchical optimization scheduling model based on the objective function and constraint conditions in the hierarchical optimization scheduling strategy;

[0082] A solving unit is used to solve the hierarchical optimization scheduling model to obtain an optimization scheduling method.

[0083] The present invention also includes a computer device, including 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 described above is implemented.

[0084] The present invention also includes a storage medium on which a computer program is stored. When the computer program is executed by a processor, the method described above is implemented.

[0085] The beneficial effects of the present invention are as follows: the present invention fully considers the system weakness of the new energy base's own external power transmission, improves the system power transmission reliability through the joint operation of thermal power units and pumped storage units, takes into account the development of ultra-high voltage direct current transmission technology and the impact of direct current power adjustment frequency on the difficulty of scheduling work, adopts a stepped power transmission method, realizes the complementary operation of pumped storage and wind, solar and thermal power, and maximizes the use of wind and solar power resources by comprehensively utilizing the regulation capabilities of pumped storage power stations and thermal power plants, while ensuring the safe and stable operation of the power grid, providing reliable technical support for the new energy transmission of large-scale wind power and photovoltaic bases. BRIEF DESCRIPTION OF THE DRAWINGS

[0086] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0087] Figure 1 is a flow chart of the method in Example 1;

[0088] Figure 2 It is a structural schematic diagram of the device in Example 1;

[0089] Figure 3 is a flow chart of the method in Example 2;

[0090] Figure 4 This is the output result diagram of the pumped storage unit in Example 2;

[0091] Figure 5 This is a graph showing the output results of the thermal power unit in Example 2;

[0092] Figure 6 This is the wind and solar power output result diagram in Example 2;

[0093] Figure 7 This is a diagram showing the power grid support output results in Example 2;

[0094] Figure 8 It is the power diagram of the new energy base in Example 2;

[0095] Fig. 9 A schematic diagram of the structure of a computer device. DETAILED DESCRIPTION

[0096] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0097] Embodiment 1:

[0098] like Figure 1 As shown: An optimization scheduling method considering the output of renewable energy transmission includes the following steps:

[0099] Establish a joint peak-shaving dispatching strategy for pumped storage and thermal power;

[0100] A hierarchical optimization scheduling strategy is established based on the joint peak-shaving scheduling strategy. The upper layer of the hierarchical optimization scheduling strategy takes the minimum volatility of the base transmission curve as the objective function and establishes scheduling constraints based on the operating characteristics of the pumped storage unit; the lower layer takes the maximum output of the base wind and solar power as the objective function and considers the scheduling constraints of the DC transmission stability and the stability of the sending-end power grid operation;

[0101] The frequency safety margin is estimated through linear constraints, and the hierarchical optimization scheduling model is established based on the objective function and constraints in the hierarchical optimization scheduling strategy;

[0102] The hierarchical optimization scheduling model is solved to obtain the optimization scheduling method.

[0103] Fully consider the system weakness of the new energy base's own power transmission output, improve the system power transmission reliability through the joint operation of thermal power units and pumped storage units, take into account the development of ultra-high voltage direct current transmission technology and the impact of direct current power adjustment frequency on the difficulty of dispatching work, adopt a stepped power transmission method, realize the complementary operation of pumped storage and wind, solar and thermal power, and maximize the use of wind and solar power resources by comprehensively utilizing the regulation capabilities of pumped storage power stations and thermal power plants. At the same time, ensure the safe and stable operation of the power grid, and provide reliable technical support for the new energy transmission of large-scale wind power and photovoltaic bases.

[0104] In this embodiment, a combined peak-shaving dispatching strategy of pumped storage and thermal power is established, including:

[0105] Consider using pumped storage to smooth the volatility of the power transmission curve of the new energy base: when the power transmission of the new energy base exceeds the upper limit of the power transmission channel capacity, the pumped storage unit will pump water to absorb excess wind and solar power output, reducing the number and depth of deep peak regulation of thermal power units; when the power transmission of the new energy base is lower than the lower limit of the power transmission channel capacity, the pumped storage unit will coordinate power generation with the thermal power unit to reduce the peak pressure of the thermal power unit.

[0106] The objective functions of the hierarchical optimization scheduling strategy include:

[0107] Upper objective function:

[0108] ;

[0109] In the formula, for DC transmission power during the period;

[0110] The lower objective function is:

[0111] ;

[0112] In the formula, is the total electricity generated by wind power and photovoltaic power; is the number of time periods in the scheduling cycle; and Wind power and photovoltaic power generation Output during the period.

[0113] The upper-level scheduling constraints in the hierarchical optimization scheduling strategy include:

[0114] Pumped storage power station capacity constraints:

[0115] ;

[0116] In the formula, for The amount of water stored in the reservoir during the period; and are the minimum and maximum storage capacities of the upper reservoir, respectively; and They are Time period The flow rate of the pumped storage unit under power generation and pumping conditions; It is the water level control target of the upper reservoir at the end of the period; is the number of pumped storage units;

[0117] Power constraints of pumped storage units:

[0118] ;

[0119] ;

[0120] In the formula, , Respectively The minimum and maximum output values ​​of the pumped storage units under power generation conditions; For the The maximum output of a pumped storage unit under pumping conditions;

[0121] Output / water conversion efficiency constraints of pumped storage power stations:

[0122] ;

[0123] In the formula, , Respectively The power generation and pumping efficiency of the pumped storage units; The maximum water discharge volume under power generation state; It is the minimum water discharge volume under power generation status; It is the maximum pumping volume under pumping state.

[0124] The lower-level scheduling constraints that consider the stability of DC transmission in the hierarchical optimization scheduling strategy include:

[0125] Sending end system stability constraints:

[0126] A simple wind power and photovoltaic base sending-end system is difficult to operate stably, and requires the coordinated operation of thermal power units, pumped storage units and wind power and photovoltaic units. That is, the number of thermal power units and pumped storage units in operation in each period must be guaranteed to a certain extent:

[0127] ;

[0128] Where: For the Thermal power units The operating status of the time period; for Time period The operating status of the pumped storage units under power generation conditions; for Time period The pumped storage unit is operating under pumping conditions; is the number of thermal power units; is the number of pumped storage units; The minimum number of thermal power units and pumped storage units that need to be started in each period.

[0129] The lower-level dispatching constraints that consider the stability of the sending-end power grid in the hierarchical optimization dispatching strategy include:

[0130] DC constant operation time constraints:

[0131] ;

[0132] ;

[0133] ;

[0134] In the formula, is a 0-1 variable indicating Whether the DC power is adjusted during the time period; Indicates the minimum DC constant operating time;

[0135] Voltage stability constraints:

[0136] ;

[0137] In the formula, is the voltage stability margin; is the total active power of the load under critical state; is the total active power of the load in the initial operating state; is the minimum stability margin, and its value range is 0~1;

[0138] Frequency safety constraints:

[0139] ;

[0140] ;

[0141] In the formula, is the frequency safety margin; is the initial frequency of the system; is the system frequency safety threshold; is the system equivalent inertia constant; are turbine parameters; is the speed regulator adjustment constant; Determined by the maximum disturbance, such as the maximum output of a thermal power unit;

[0142] Frequency response constraints of thermal power units:

[0143] ;

[0144] In the formula, For the A binary variable indicating whether the thermal power unit participates in the primary frequency response; For the A binary variable for the start and stop status of a thermal power unit;

[0145] Output constraints of thermal power units:

[0146] ;

[0147] In the formula, and Respectively The minimum and maximum output of each thermal power unit; express Thermal power units The operating status of

[0148] Wind power and photovoltaic output constraints:

[0149] ;

[0150] In the formula, and Wind power and photovoltaic power The maximum predicted output for the time period;

[0151] Grid support power constraints:

[0152] ;

[0153] ;

[0154] In the formula, for The grid support power during the period; for DC transmission power during the period; is the grid support factor, which is defined as the ratio of the grid support power ceiling to the DC transmission planned power; The number of calculation period periods for supporting balancing constraints for the power grid;

[0155] DC transmission channel capacity constraints:

[0156] ;

[0157] In the formula, for DC transmission power during the period; and for Wind power and photovoltaic output during the time period; for Output of thermal power units during the period; for Power generation capacity of pumped storage units during period; for Pumping power of pumped storage units during the period; for The grid support power during the period; It is the upper limit of DC channel transmission capacity.

[0158] In this embodiment, the frequency safety margin is estimated by linear constraints, and the parameters , , The frequency safety margin is estimated based on the constraints of

[0159] ;

[0160] ;

[0161] ;

[0162] In the formula, , , They are the predicted power generation of wind farms, photovoltaic power plants, and load demand; For the A binary variable for the start and stop status of a thermal power unit; No. Inertia constant of thermal power units; For the The maximum output of the thermal power units; , , Respectively A binary variable indicating whether a thermal power unit, wind farm, or photovoltaic power station participates in the primary frequency response; and are the comprehensive inertia constants of wind farm and photovoltaic power station respectively; For the Mechanical power gain coefficient of thermal power units; For the The proportion of electricity generated by high-pressure turbines in thermal power plants; For the The speed governor adjustment constant of each thermal power unit; and are the droop coefficients of wind farms and photovoltaic power plants, respectively;

[0163] The output space of the response unit is reserved to provide a primary frequency response, satisfying the following constraints:

[0164] ;

[0165] ;

[0166] ;

[0167] In the formula, the lowest frequency point Greater than the quasi-steady-state frequency; parameter The value of is less than 1.

[0168] Among them, solving the hierarchical optimization scheduling model includes:

[0169] Yalmip is used to call the Gurobi solver to solve the hierarchical optimization scheduling model, and the active output of thermal power units, wind farms, photovoltaic power stations, pumped storage power stations and other power grid support at each moment is obtained, thereby obtaining the output of new energy bases.

[0170] like Figure 2 As shown, this embodiment also includes an optimization scheduling device considering the output of new energy transmission, using the above method, including:

[0171] Joint peak-shaving dispatching unit, used to establish a joint peak-shaving dispatching strategy for pumped storage and thermal power;

[0172] The hierarchical optimization dispatching unit is used to establish a hierarchical optimization dispatching strategy according to the joint peak-shaving dispatching strategy. The upper layer of the hierarchical optimization dispatching strategy takes the minimum volatility of the base transmission curve as the objective function and establishes dispatching constraints based on the operating characteristics of the pumped storage unit; the lower layer takes the maximum output of the base wind and solar power as the objective function and considers the dispatching constraints of the DC transmission stability and the stability of the sending-end power grid operation;

[0173] A modeling unit, used to estimate the frequency safety margin through linear constraints and establish a hierarchical optimization scheduling model based on the objective function and constraint conditions in the hierarchical optimization scheduling strategy;

[0174] The solving unit is used to solve the hierarchical optimization scheduling model to obtain the optimization scheduling method.

[0175] Embodiment 2:

[0176] like Figure 3 As shown, this embodiment includes an optimization scheduling method considering the output of new energy transmission, including the following steps:

[0177] S110: Combined peak-shaving dispatching strategy of pumped storage and thermal power;

[0178] S120: The upper layer optimizes the power of the pumped storage units with the goal of minimizing the volatility of the base transmission curve, and the lower layer optimizes the output of the thermal power units with the goal of maximizing the wind and solar power output of the base; the upper layer establishes the dispatching constraints of the pumped storage unit operation characteristics, and the lower layer establishes the dispatching constraints mainly considering the stability of DC transmission and the stability of the operation of the sending-end power grid;

[0179] S130: estimating the frequency safety margin through a series of linear constraints, and constructing a hierarchical optimization dispatch model of wind-solar-thermal-pumped storage based on the objective function and the constraint conditions;

[0180] S140: Solve the mixed integer linear programming model to obtain a wind-solar-thermal-pumped storage hierarchical optimization scheduling method.

[0181] Specifically, the combined peak-shaving dispatching strategy of pumped storage and thermal power includes:

[0182] Consider using pumped storage to smooth the volatility of the new energy base's transmission output curve. For example, when the new energy base's power transmission exceeds the upper limit of the power transmission channel's capacity, the pumped storage unit pumps water to absorb excess wind and solar power output, while reducing the number and depth of deep peak regulation of thermal power units. When the new energy base's power transmission is lower than the lower limit of the power transmission channel's capacity, the pumped storage unit and the thermal power unit coordinate power generation to reduce the peak pressure of the thermal power units and assist the base in completing the transmission plan.

[0183] Specifically, the objective function of hierarchical optimization scheduling of the transmission output of the new energy base in Shagohuang area is established, including:

[0184] Upper objective function:

[0185] ;

[0186] in, for DC transmission power during the period;

[0187] The lower objective function is:

[0188] ;

[0189] in, is the total electricity generated by wind power and photovoltaic power; is the number of time periods in the scheduling cycle; and Wind power and photovoltaic power generation Output during the period.

[0190] Specifically, the upper-level dispatch constraints of the pumped storage unit operation characteristics are established, including:

[0191] Pumped storage power station capacity constraints:

[0192] ;

[0193] in, for The amount of water stored in the reservoir during the period; and are the minimum and maximum storage capacities of the upper reservoir, respectively; and They are Time period The flow rate of the pumped storage unit under power generation and pumping conditions; It is the water level control target of the upper reservoir at the end of the period; is the number of pumped storage units;

[0194] Power constraints of pumped storage units:

[0195] ;

[0196] ;

[0197] in, , Respectively The minimum and maximum output values ​​of the pumped storage units under power generation conditions; For the The maximum output of a pumped storage unit under pumping conditions;

[0198] Output / water conversion efficiency constraints of pumped storage power stations:

[0199] ;

[0200] in, , Respectively The power generation and pumping efficiency of the pumped storage units; The maximum water discharge volume under power generation state; It is the minimum water discharge volume under power generation state; is the maximum water pumping capacity under pumping state;

[0201] like Figure 4 As shown, the example of the present invention includes the output of six pumped storage units. During the periods of 00:00-14:00 and 23:00-24:00, the pumped storage units are in the power generation state, providing a certain guarantee for the output of the entire external transmission system; during the period of 14:00-23:00, the pumped storage units are in the pumping state, providing a certain peak load regulation and wind and solar output absorption capacity for the normal operation of the system's external transmission output;

[0202] Specific pumped storage power station parameters are shown in Table 1 and Table 2:

[0203] Table 1 Pumped storage power station parameters

[0204] <![CDATA[Minimum storage capacity of the upper reservoir (m 3 )]]> 0 <![CDATA[Maximum storage capacity of the upper reservoir (m 3 ).]]> 2000 <![CDATA[Final reservoir capacity (m 3 ).]]> 1000 <![CDATA[Initial reservoir capacity (m 3 ).]]> 1000 Maximum number of starts and stops of pumped storage units under power generation conditions (times) 4 Maximum number of starts and stops of pumped storage units under pumping conditions (times) 4

[0205] Table 2 Pumped storage unit parameters

[0206] Pumped storage unit number 1 2 3 4 5 6 Minimum power generation (MW) 52.40 52.40 38.41 38.41 38.41 38.41 Maximum power generation (MW) 101.42 101.42 105.64 105.64 105.64 105.64 <![CDATA[Minimum water discharge (m 3 )]]> 28.79 28.79 21.10 21.10 21.10 21.10 <![CDATA[Maximum water discharge (m 3 )]]> 51.59 51.59 51.59 51.59 51.59 51.59 Maximum pumping power (MW) 158.28 158.28 158.28 158.28 158.28 158.28 <![CDATA[Maximum pumping volume (m 3 )]]> 61.90 61.90 61.90 61.90 61.90 61.90

[0207] Specifically, the lower-level dispatching constraints that take into account the stability of DC transmission are established, including:

[0208] Sending end system stability constraints:

[0209] A simple wind power and photovoltaic base sending-end system is difficult to operate stably, and requires the coordinated operation of thermal power units, pumped storage units and wind power and photovoltaic units. That is, the number of thermal power units and pumped storage units in operation in each period must be guaranteed to a certain extent:

[0210] ;

[0211] in: For the Thermal power units The operating status of the time period; for Time period The operating status of the pumped storage units under power generation conditions; for Time period The pumped storage unit is operating under pumping conditions; is the number of thermal power units; is the number of pumped storage units; The minimum number of thermal power units and pumped storage units that need to be started in each period.

[0212] Specifically, the lower-level constraints that take into account the stability of power grid operation are established, including:

[0213] DC constant operation time constraints:

[0214] Considering the development of UHV DC transmission technology and the impact of DC power adjustment frequency on the difficulty of dispatching, a step-by-step transmission method is adopted to meet the following constraints:

[0215] ;

[0216] ;

[0217] ;

[0218] in, is a 0-1 variable indicating Whether the DC power is adjusted during the time period; Indicates the minimum DC constant operating time;

[0219] Voltage stability constraints:

[0220] Power systems with high wind and solar penetration rates require sufficient voltage stability margin to prevent voltage collapse events. Voltage stability should be considered during operation optimization to improve voltage stability under different operating conditions:

[0221] ;

[0222] in, is the voltage stability margin; is the total active power of the load under critical state; is the total active power of the load in the initial operating state; is the minimum stability margin, and its value range is (0,1);

[0223] Frequency safety constraints:

[0224] When the wind and solar share is high, the online capacity of synchronous generators is reduced and the inertia level of the system is low. After a generation-load imbalance occurs in an accident situation, the system frequency will drop faster, which may lead to frequency security violations or even system-wide instability. Considering frequency dynamics in the dispatch model, more synchronous generators can be dispatched to provide inertia to ensure the frequency security of the system. According to the definition of the frequency safety margin, the upper bound of the power imbalance causes the frequency minimum point to be within a pre-defined threshold. Therefore, limiting the frequency minimum point is equivalent to limiting the power disturbance to below the frequency safety margin:

[0225] ;

[0226] ;

[0227] in, is the frequency safety margin; is the initial frequency of the system; is the system frequency safety threshold; is the system equivalent inertia constant; are turbine parameters; is the speed regulator adjustment constant; Determined by the maximum disturbance, such as the maximum output of a thermal power unit;

[0228] Frequency response constraints of thermal power units:

[0229] ;

[0230] in, For the A binary variable indicating whether the thermal power unit participates in the primary frequency response; For the A binary variable for the start and stop status of a thermal power unit;

[0231] Output constraints of thermal power units:

[0232] ;

[0233] in, and Respectively The minimum and maximum output of each thermal power unit; express Thermal power units The operating status of

[0234] like Figure 5As shown, the example of the present invention includes the output of ten thermal power units. During the period of 00:00-22:00, the thermal power units basically maintain a high and stable output, providing strong support for the external output of the system; during the period of 22:00-24:00, as some thermal power units are shut down, the output power of the thermal power units begins to gradually decrease until it reaches 0;

[0235] The specific parameters of the thermal power unit are shown in Table 3:

[0236] Table 3 Thermal power unit parameters

[0237] Unit No. 1 2 3 4 5 6 7 8 9 10 Output upper limit (MW) 250 677.871 650 632 508 650 560 540 830 1000 Output lower limit (MW) 100 271.148 260 252.8 203.2 260 224 216 332 400

[0238] Wind power and photovoltaic output constraints:

[0239] ;

[0240] in, and Wind power and photovoltaic power The maximum predicted output for the time period;

[0241] like Figure 6 As shown, the example of the present invention includes the output of one wind farm and one photovoltaic power station. During the periods of 00:00-10:00 and 19:00-24:00, due to the low intensity of solar radiation, photovoltaic power generation is almost non-existent, and wind power generation is the main form of power generation; during the period of 10:00-19:00, wind power and photovoltaic power generation work together, and the wind power generation power is basically higher than the photovoltaic power generation;

[0242] Specific wind farm and photovoltaic power station parameters are shown in Table 4:

[0243] Table 4 Wind farm and photovoltaic power station parameters

[0244] time Maximum wind power output (MW) Maximum photovoltaic output (MW) 1 560 0 2 640 0 3 720 0 4 640 0 5 560 0 6 320 0 7 160 10 8 80 20 9 80 40 10 160 80 11 120 120 12 80 160 13 120 170 14 160 60 15 240 120 16 320 80 17 400 40 18 480 20 19 520 0 20 600 0 21 480 0 22 560 0 23 640 0 24 720 0

[0245] Grid support power constraints:

[0246] In order to ensure the reliability of power transmission for bases with a high proportion of renewable energy and avoid the problem of overly conservative planning results due to extreme wind and solar output scenarios, support channels from other power grids at the sending end are considered to assist the base in completing the power transmission plan. In order to avoid long-term demand for additional power from other power grids, the support power must meet the periodic power balance constraint, that is, the net power supported within the specified period is equal to 0;

[0247] ;

[0248] ;

[0249] in, for The grid support power during the period; for DC transmission power during the period; is the grid support factor, which is defined as the ratio of the grid support power ceiling to the DC transmission planned power; The number of calculation period periods for supporting balancing constraints for the power grid;

[0250] like Figure 7 As shown, the example of the present invention includes the power support conditions of other sending-end power grids, and other power grids actively participate in the dispatching output of the system. Within the 24 hours of the main dispatching of this model, the power grid support output fluctuates, serving as both a power source and a load. In the subsequent time period of 168 hours in a week, the power grid support maintains a low power output to meet the net support power equal to 0 within the specified period (1 week).

[0251] DC transmission channel capacity constraints:

[0252] ;

[0253] in, for DC transmission power during the period; and for Wind power and photovoltaic output during the time period; for Output of thermal power units during the period; for Power generation capacity of pumped storage units during period; for Pumping power of pumped storage units during the period; for The grid support power during the period; The upper limit of the DC channel transmission capacity;

[0254] like Figure 8 As shown, the example of the present invention includes the output of the new energy base. During the period of 00:00-22:00, the output is in a stable state, and the transmission curve remains unchanged; during the period of 22:00-24:00, with the gradual withdrawal of the thermal power units, the transmission power of the system also gradually decreases.

[0255] Specifically, through the parameters , , A series of linear constraints are used to estimate the frequency safety margin, including:

[0256] ;

[0257] ;

[0258] ;

[0259] in, , , They are the predicted power generation of wind farms, photovoltaic power plants, and load demand; For the A binary variable for the start and stop status of a thermal power unit; No. Inertia constant of thermal power units; For the The maximum output of the thermal power units; , , Respectively A binary variable indicating whether a thermal power unit, wind farm, or photovoltaic power station participates in the primary frequency response; and are the comprehensive inertia constants of wind farm and photovoltaic power station respectively; For the Mechanical power gain coefficient of thermal power units; For the The proportion of electricity generated by high-pressure turbines in thermal power plants; For the The speed governor adjustment constant of each thermal power unit; and are the droop coefficients of wind farms and photovoltaic power plants, respectively;

[0260] A certain number of response units are reserved for output space to provide a frequency response, satisfying the following constraints:

[0261] ;

[0262] ;

[0263] ;

[0264] Among them, the lowest frequency Usually greater than the quasi-steady-state frequency; parameter The value of is less than 1.

[0265] Specifically, the wind-solar-thermal-pumped storage layered optimization scheduling model is solved to obtain a wind-solar-thermal-pumped storage layered optimization scheduling method, including:

[0266] Yalmip is used to call the Gurobi solver to solve the wind-solar-thermal-pumped storage hierarchical optimization scheduling model, and the active output of thermal power units, wind farms, photovoltaic power stations, pumped storage power stations and other power grid support at each moment is obtained, and the output of new energy bases is further obtained.

[0267] See also Fig. 9 A computer device 400 provided in an embodiment of the present application includes: a processor 410 and a memory 420, wherein the memory 420 stores a computer program executable by the processor 410, and when the computer program is executed by the processor 410, the above method is executed.

[0268] The embodiment of the present application further provides a storage medium 430 on which a computer program is stored. When the computer program is run by the processor 410, the above method is executed.

[0269] Among them, the storage medium 430 can be implemented by any type of volatile or non-volatile storage device or a combination thereof, such as static random access memory (SRAM), electrically erasable programmable read-only memory (EEPROM), erasable programmable read-only memory (EPROM), programmable red-only memory (PROM), read-only memory (ROM), magnetic storage, flash memory, disk or optical disk.

[0270] In the description of the present invention, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. "Multiple" means two or more, unless otherwise clearly and specifically defined.

[0271] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0272] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, unless they are contradictory.

[0273] Any process or method description in a flowchart or otherwise described herein may be understood to represent a module, segment or portion of code that includes one or more executable instructions for implementing the steps of a specific logical function or process, and the scope of the preferred embodiments of the present invention includes alternative implementations in which functions may not be performed in the order shown or discussed, including performing functions in a substantially simultaneous manner or in the reverse order depending on the functions involved, which should be understood by those skilled in the art to which the embodiments of the present invention belong.

[0274] The logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as an ordered list of executable instructions for implementing logical functions, and can be embodied in any computer-readable medium for use by an instruction execution system, device or apparatus (such as a computer-based system, a system including a processor, or other system that can fetch instructions from an instruction execution system, device or apparatus and execute instructions), or in combination with these instruction execution systems, devices or apparatuses. For the purposes of this specification, "computer-readable medium" can be any device that can contain, store, communicate, propagate or transmit a program for use by an instruction execution system, device or apparatus, or in combination with these instruction execution systems, devices or apparatuses. More specific examples (non-exhaustive list) of computer-readable media include the following: an electrical connection with one or more wires (electronic device), a portable computer disk box (magnetic device), a random access memory (RAM), a read-only memory (ROM), an erasable and programmable read-only memory (EPROM or flash memory), an optical fiber device, and a portable compact disk read-only memory (CDROM). In addition, the computer-readable medium may even be paper or other suitable medium on which the program is printed, since the program may be obtained electronically, for example, by optically scanning the paper or other medium and then editing, interpreting or processing in other suitable ways if necessary, and then stored in a computer memory.

[0275] It should be understood that the various parts of the present invention can be implemented by hardware, software, firmware or a combination thereof. In the above-mentioned embodiments, multiple steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented by hardware, as in another embodiment, it can be implemented by any one of the following technologies known in the art or their combination: a discrete logic circuit having a logic gate circuit for implementing a logic function for a data signal, a dedicated integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0276] A person skilled in the art may understand that all or part of the steps in the method for implementing the above-mentioned embodiment may be completed by instructing related hardware through a program, and the program may be stored in a computer-readable storage medium, which, when executed, includes one or a combination of the steps of the method embodiment.

[0277] The storage medium mentioned above may be a read-only memory, a magnetic disk or an optical disk, etc. Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limiting the present invention. A person of ordinary skill in the art may change, modify, replace and modify the above embodiments within the scope of the present invention.

Claims

1. An optimization scheduling method considering the output of renewable energy, characterized in that: The steps include: Establish a joint peak-shaving dispatching strategy for pumped storage and thermal power; A hierarchical optimization scheduling strategy is established according to the joint peak-shaving scheduling strategy, wherein the upper layer of the hierarchical optimization scheduling strategy takes the minimum volatility of the base transmission curve as the objective function and establishes scheduling constraints based on the operating characteristics of the pumped storage unit; The lower layer takes the maximum wind and solar power output of the base as the objective function, taking into account the dispatch constraints of DC transmission stability and the stability of the power grid operation at the sending end; The frequency safety margin is estimated by linear constraints, and a hierarchical optimization scheduling model is established based on the objective function and constraint conditions in the hierarchical optimization scheduling strategy; Solving the hierarchical optimization scheduling model to obtain an optimization scheduling method; The objective function of the hierarchical optimization scheduling strategy includes: Upper objective function: ； In the formula, is the DC transmission power in period t; The lower objective function is: ； Where, f is the total power generation of wind power and photovoltaic power; T is the number of time periods in the scheduling cycle; and are the output of wind power and photovoltaic power generation in period t respectively; The upper-level scheduling constraints in the hierarchical optimization scheduling strategy include: Pumped storage power station capacity constraints: ； In the formula, is the water storage capacity of the upper reservoir during period t; and are the minimum and maximum storage capacities of the upper reservoir, respectively; and are the flow rates of the nth pumped storage unit in power generation and pumping conditions during period t respectively; It is the water level control target of the upper reservoir at the end of the period; is the number of pumped storage units; Power constraints of pumped storage units: ； ； In the formula, , are the minimum and maximum output values ​​of the nth pumped storage unit under power generation conditions; is the maximum output of the nth pumped storage unit under pumping conditions; Output / water conversion efficiency constraints of pumped storage power stations: ； In the formula, , are the power generation and pumping efficiency of the nth pumped storage unit, respectively; The lower-level scheduling constraints that consider the stability of DC transmission in the hierarchical optimization scheduling strategy include: Stability constraints of the sending end system: A simple wind power and photovoltaic base sending-end system is difficult to operate stably, and requires the coordinated operation of thermal power units, pumped storage units and wind power and photovoltaic units. That is, the number of thermal power units and pumped storage units in operation in each period must be guaranteed to a certain extent: ； Where: is the operating status of the i-th thermal power unit in period t; is the operating status of the nth pumped storage unit under power generation conditions during period t; is the operating status of the nth pumped storage unit under pumping conditions during period t; is the number of thermal power units; is the number of pumped storage units; M is the minimum number of thermal power units and pumped storage units that need to be started in each period; The lower-level dispatching constraints that consider the stability of the sending-end power grid operation in the hierarchical optimization dispatching strategy include: DC constant operation time constraints: ； ； ； In the formula, is a 0-1 variable indicating whether the DC power is adjusted during period t; Indicates the minimum DC constant operating time; Voltage stability constraints: ； In the formula, is the voltage stability margin; is the total active power of the load under critical state; is the total active power of the load in the initial operating state; is the minimum stability margin, and its value range is 0~1; Frequency safety constraints: ； ； In the formula, is the frequency safety margin; is the initial frequency of the system; is the system frequency safety threshold; H is the system equivalent inertia constant; is the turbine parameter; R is the governor regulation constant; Determined by the maximum disturbance, such as the maximum output of a thermal power unit; Frequency response constraints of thermal power units: ； In the formula, is a binary variable indicating whether the i-th thermal power unit participates in the primary frequency response; is the binary variable of the start / stop status of the i-th thermal power unit; Output constraints of thermal power units: ； In the formula, and are the minimum and maximum outputs of the i-th thermal power unit respectively; Indicates the operating status of thermal power unit i during period t; Wind power and photovoltaic output constraints: ； In the formula, and are the maximum predicted outputs of wind power and photovoltaic power in period t respectively; Grid support power constraints: ； ； In the formula, is the grid support power in time period t; is the DC transmission power in period t; is the grid support coefficient, which is defined as the ratio of the grid support power upper limit to the DC transmission planned power; H is the number of calculation cycles for the grid support balance constraint; DC transmission channel capacity constraints: ； In the formula, is the DC transmission power in period t; and is the wind power and photovoltaic power output during period t; is the output of thermal power units during period t; is the power generation capacity of the pumped storage unit during period t; is the pumping power of the pumped storage unit during period t; is the grid support power in time period t; The upper limit of the DC channel transmission capacity; In estimating the frequency safety margin through linear constraints, the parameters , , The frequency safety margin is estimated based on the constraints of ； ； ； In the formula, , , They are the predicted power generation of wind farms, photovoltaic power plants, and load demand respectively; is the binary variable of the start / stop status of the i-th thermal power unit; Inertia constant of the i-th thermal power unit; is the maximum output of the i-th thermal power unit; , , are binary variables indicating whether the i-th thermal power unit, wind farm, and photovoltaic power station participate in the primary frequency response; and are the comprehensive inertia constants of wind farm and photovoltaic power station respectively; is the mechanical power gain coefficient of the i-th thermal power unit; is the proportion of power generation of the high-pressure turbine of the i-th thermal power unit; is the speed regulator regulation constant of the i-th thermal power unit; and are the droop coefficients of wind farms and photovoltaic power plants, respectively; The output space of the response unit is reserved to provide a primary frequency response, satisfying the following constraints: ； ； ； In the formula, the lowest frequency Greater than the quasi-steady-state frequency; parameter The value of is less than 1.

2. The optimization scheduling method considering the output of new energy according to claim 1 is characterized in that: The strategy of establishing a combined peak-shaving dispatching strategy of pumped storage and thermal power includes: Consider using pumped storage to smooth the volatility of the power transmission curve of the new energy base: when the power transmission of the new energy base exceeds the upper limit of the power transmission channel capacity, the pumped storage unit will pump water to absorb excess wind and solar power output, reducing the number and depth of deep peak regulation of thermal power units; when the power transmission of the new energy base is lower than the lower limit of the power transmission channel capacity, the pumped storage unit will coordinate power generation with the thermal power unit to reduce the peak pressure of the thermal power unit.

3. The optimization scheduling method considering the output of new energy according to claim 1 is characterized in that: The solving of the hierarchical optimization scheduling model includes: The hierarchical optimization scheduling model is solved by calling the Gurobi solver using Yalmip to obtain the active output of thermal power units, wind farms, photovoltaic power stations, pumped storage power stations and other power grid support at each moment, thereby obtaining the output of the new energy base.

4. An optimization scheduling device considering the output of new energy, characterized in that: Use of the method according to any one of claims 1 to 3, comprising: Joint peak-shaving dispatching unit, used to establish a joint peak-shaving dispatching strategy for pumped storage and thermal power; A hierarchical optimization dispatching unit is used to establish a hierarchical optimization dispatching strategy according to the joint peak-shaving dispatching strategy. The upper layer of the hierarchical optimization dispatching strategy takes the minimum volatility of the base transmission curve as the objective function and establishes dispatching constraints based on the operating characteristics of the pumped storage unit; the lower layer takes the maximum output of the base wind and solar power as the objective function and considers the dispatching constraints of the DC transmission stability and the operation stability of the sending-end power grid; A modeling unit, used to estimate the frequency safety margin through linear constraints, and establish a hierarchical optimization scheduling model based on the objective function and constraint conditions in the hierarchical optimization scheduling strategy; A solving unit is used to solve the hierarchical optimization scheduling model to obtain an optimization scheduling method.

5. A computer device comprising a memory, a processor and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, the method according to any one of claims 1 to 3 is implemented.

6. A storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the method according to any one of claims 1 to 3 is implemented.

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