A method and system for optimizing unit output considering wind-thermal combined frequency regulation

Abstract

The present application relates to a kind of unit output optimization method and system considering wind-fire combined frequency modulation, comprising: obtaining the primary frequency modulation reserve capacity required by power system;The primary frequency modulation reserve capacity required by power system is substituted into the unit output optimization model constructed in advance, the unit output optimization model is solved, and the optimal output of thermal power unit and the optimal output of wind turbine in power system are obtained;Wherein, the constraint condition of the pre-established unit output optimization model includes: primary frequency modulation capability constraint condition.The present application establishes unit output optimization model by considering the primary frequency modulation capability of thermal power unit when participating in deep peak shaving and the primary frequency modulation capability of wind turbine, and adjusts unit output by optimization model, so that power system has deep peak shaving capability while also having sufficient frequency modulation margin.

Description

Technical Field

[0001] The present invention relates to the field of load distribution of power systems, and in particular to a method and system for optimizing unit output considering wind-fire combined frequency regulation. Background Art

[0002] Renewable energy power generation has the characteristics of intermittency, randomness, and anti-peak regulation. As the penetration rate of new energy in the power system increases, the proportion of thermal power gradually decreases, and its anti-peak regulation characteristics have an increased impact on the power grid.

[0003] In order to minimize the occurrence of large-scale wind curtailment, regions rich in wind energy carry out deep peak-shaving modifications on thermal power units to significantly improve the system's peak-shaving capacity during low-load periods. However, when thermal power units participate in deep peak-shaving, their output range will decrease, and the frequency regulation capability of thermal power units is related to their operating range. That is, when thermal power units participate in deep peak-shaving, the frequency regulation capability of the power system will decrease.

[0004] In order to ensure the safe and stable operation of the system, it is necessary to ensure that the system has sufficient frequency regulation capabilities. Therefore, how to ensure that the system has sufficient frequency regulation margin when thermal power units participate in deep peak regulation is a difficult problem that we urgently need to solve.

[0005] At present, no corresponding solution strategy has been proposed. Summary of the Invention

[0006] In view of the shortcomings of the existing technology, the purpose of the present invention is to provide a unit output optimization method taking into account the combined frequency regulation of wind and thermal power units. The method establishes a unit output optimization model by considering the primary frequency regulation capability of thermal power units when participating in deep peak regulation and the primary frequency regulation capability of wind power units. The unit output is adjusted through the optimization model, so that the power system has sufficient frequency regulation margin while having deep peak regulation capability.

[0007] The purpose of the present invention is achieved by adopting the following technical solutions:

[0008] The present invention provides a method for optimizing unit output by considering wind-fire combined frequency regulation, wherein the method comprises:

[0009] Obtain the primary frequency regulation reserve capacity required by the power system;

[0010] Substituting the primary frequency regulation reserve capacity required by the power system into a pre-built unit output optimization model, solving the unit output optimization model, and obtaining the optimal output of the thermal power units and the optimal output of the wind power units in the power system;

[0011] The constraints of the pre-established unit output optimization model include: primary frequency regulation capability constraints;

[0012] The primary frequency regulation capability constraint condition is constructed based on the correspondence between the primary frequency regulation capability of the thermal power unit when participating in deep peak regulation and the output of the thermal power unit when participating in deep peak regulation, and the correspondence between the primary frequency regulation capability of the wind turbine unit and the output of the wind turbine unit.

[0013] Preferably, the primary frequency modulation capability constraint condition is determined as follows:

[0014]

[0015] In the above formula, ΔP Ti is the primary frequency regulation capability of the i-th thermal power unit in the power system when participating in deep peak regulation, ΔP Wj is the primary frequency regulation capability of the jth wind turbine in the power system, ΔP R is the primary frequency regulation reserve capacity required by the power system, i∈(1~N), N is the total number of thermal power units in the power system, j∈(1~M), M is the total number of wind turbines in the power system.

[0016] Furthermore, ΔP is determined as follows: Ti The output P of the i-th thermal power unit in the power system when participating in deep peak regulation Ti The corresponding relationship:

[0017]

[0018] Furthermore, the ΔP is determined as follows: Wj The output P of the jth wind turbine in the power system Wj The corresponding relationship:

[0019]

[0020] In the above formula, λ Wj is the minimum output decision variable of the j-th wind turbine in the power system, k 0j is the output coefficient of the j-th wind turbine in the power system, d Wj % is the load reduction level of the jth wind turbine generator set in the power system, v Wj is the wind speed that the j-th wind turbine in the power system is subjected to, P WN,j is the rated output of the jth wind turbine in the power system;

[0021] Wherein, the λ is determined as follows: Wj :

[0022]

[0023] In the above formula, P Wj is the output of the jth wind turbine in the power system;

[0024] Determine k as follows:0j :

[0025]

[0026] In the above formula, C p,max is the maximum wind energy capture coefficient of wind turbines in the power system, A Wj is the area swept by the rotor blades of the j-th wind turbine in the power system, and ρ is the atmospheric density.

[0027] Preferably, the objective function of the pre-established unit output optimization model is determined as follows:

[0028]

[0029] In the above formula, f is the objective function value of the unit output optimization model, C Ti is the coal consumption of the i-th thermal power unit in the power system, g Ti is the pollutant emission of the i-th thermal power unit in the power system, F Wj is the wind curtailment of the j-th wind turbine in the power system, i∈(1~N), N is the total number of thermal power units in the power system, j∈(1~M), M is the total number of wind turbines in the power system;

[0030] Wherein, the C is determined as follows: Ti :

[0031]

[0032] In the above formula, a Ti is the first coal consumption characteristic coefficient of the i-th thermal power unit in the power system, b Ti is the second coal consumption characteristic coefficient of the i-th thermal power unit in the power system, is the third coal consumption characteristic coefficient of the i-th thermal power unit in the power system, P Ti is the output of the i-th thermal power unit in the power system when participating in deep peak regulation;

[0033] Determine the g as follows: Ti (P Ti ):

[0034]

[0035] In the above formula, V Ti is the pollutant emission of the i-th thermal power unit in the power system when operating at rated output, α Ti is the first pollutant emission characteristic coefficient of the i-th thermal power unit in the power system, β Ti is the second pollutant emission characteristic coefficient of the i-th thermal power unit in the power system, γ Tiis the third pollutant emission characteristic coefficient of the i-th thermal power unit in the power system, λ Ti is the fourth pollutant emission characteristic coefficient of the i-th thermal power unit in the power system;

[0036] Determine the F as follows: Wj :

[0037] F Wj =(P opt，j -P Wj )T s

[0038] In the above formula, P opt，j is the optimal wind power captured by the j-th wind turbine in the power system, T s is the wind speed sampling interval, P Wj is the output of the jth wind turbine in the power system;

[0039] Determine the P as follows: opt，j :

[0040]

[0041] In the above formula, k 0j is the output coefficient of the jth wind turbine in the power system, v Wj is the wind speed that the j-th wind turbine in the power system is subjected to, P WN,j is the rated output of the jth wind turbine in the power system.

[0042] Furthermore, the constraints of the pre-established unit output optimization model further include: power balance constraints, thermal power unit output constraints, and wind power unit output constraints;

[0043] The power balance constraint condition is determined as follows:

[0044]

[0045] In the above formula, P L is the total load of the power system;

[0046] The output constraint condition of the thermal power unit is determined as follows:

[0047] P Ti,min ≤P Ti ≤P Ti,max

[0048] In the above formula, P Ti,min is the lower limit of the output of the j-th wind turbine in the power system, P Ti,max is the output upper limit of the j-th wind turbine in the power system;

[0049] The output constraint condition of the wind turbine generator set is determined as follows:

[0050] P Wj,min ≤P Wj ≤P Wj,max

[0051] In the above formula, P Wj,min is the lower limit of the output of the i-th thermal power unit in the power system when participating in deep peak regulation, P Wj,max is the output upper limit of the i-th thermal power unit in the power system when participating in deep peak regulation.

[0052] The present invention provides a unit output optimization system considering wind-fire combined frequency regulation, wherein the improvement is that the system comprises:

[0053] An acquisition module is used to obtain the primary frequency regulation reserve capacity required by the power system;

[0054] A solution module is used to substitute the primary frequency regulation reserve capacity required by the power system into a pre-built unit output optimization model, solve the unit output optimization model, and obtain the optimal output of the thermal power unit and the optimal output of the wind power unit in the power system;

[0055] The constraints of the pre-established unit output optimization model include: primary frequency regulation capability constraints;

[0056] The primary frequency regulation capability constraint condition is constructed based on the correspondence between the primary frequency regulation capability of the thermal power unit when participating in deep peak regulation and the output of the thermal power unit when participating in deep peak regulation, and the correspondence between the primary frequency regulation capability of the wind turbine unit and the output of the wind turbine unit.

[0057] Preferably, the primary frequency modulation capability constraint condition is determined as follows:

[0058]

[0059] In the above formula, ΔP Ti is the primary frequency regulation capability of the i-th thermal power unit in the power system when participating in deep peak regulation, ΔP Wj is the primary frequency regulation capability of the jth wind turbine in the power system, ΔP R is the primary frequency regulation reserve capacity required by the power system, i∈(1~N), N is the total number of thermal power units in the power system, j∈(1~M), M is the total number of wind turbines in the power system.

[0060] Furthermore, ΔP is determined as follows: Ti The output P of the i-th thermal power unit in the power system when participating in deep peak regulation Ti The corresponding relationship:

[0061]

[0062] Furthermore, the ΔP is determined as follows: Wj The output P of the jth wind turbine in the power system Wj The corresponding relationship:

[0063]

[0064] In the above formula, λ Wj is the minimum output decision variable of the j-th wind turbine in the power system, k 0j is the output coefficient of the j-th wind turbine in the power system, d Wj % is the load reduction level of the jth wind turbine generator set in the power system, v Wj is the wind speed that the j-th wind turbine in the power system is subjected to, P WN,j is the rated output of the jth wind turbine in the power system;

[0065] Wherein, the λ is determined as follows: Wj :

[0066]

[0067] In the above formula, P Wj is the output of the jth wind turbine in the power system;

[0068] Determine k as follows: 0j :

[0069]

[0070] In the above formula, C p,max is the maximum wind energy capture coefficient of wind turbines in the power system, A Wj is the area swept by the rotor blades of the j-th wind turbine in the power system, and ρ is the atmospheric density.

[0071] Compared with the closest prior art, the present invention has the following beneficial effects:

[0072] The technical solution provided by the present invention obtains the primary frequency regulation reserve capacity required by the power system; substitutes the primary frequency regulation reserve capacity required by the power system into a pre-constructed unit output optimization model, solves the unit output optimization model, and obtains the optimal output of the thermal power units and the optimal output of the wind turbine units in the power system; wherein the constraints of the pre-constructed unit output optimization model include: a primary frequency regulation capacity constraint; the primary frequency regulation capacity constraint is constructed based on the correspondence between the primary frequency regulation capacity of the thermal power units when participating in deep peak regulation and the output of the thermal power units when participating in deep peak regulation, as well as the correspondence between the primary frequency regulation capacity of the wind turbine units and the output of the wind turbine units. This solution establishes a unit output optimization model by considering the primary frequency regulation capacity of the thermal power units when participating in deep peak regulation and the primary frequency regulation capacity of the wind turbine units, and adjusts the unit output through the optimization model, so that the power system has sufficient frequency regulation margin while having deep peak regulation capability.

[0073] The technical solution provided by the present invention obtains the unit output that achieves the maximum wind curtailment, minimum coal consumption and minimum pollutant output by solving the unit output optimization model, thereby making the most reasonable use of resources while ensuring the environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0074] Figure 1 This is a flow chart of a method for optimizing unit output taking into account wind-fire combined frequency regulation;

[0075] Figure 2 This is the result of a frequency regulation test of a thermal power unit in an embodiment of the present invention;

[0076] Figure 3 Schematic diagram of active power control strategy of wind turbine generator system according to an embodiment of the present invention;

[0077] Figure 4 It is a structural diagram of the unit output optimization system taking into account the combined frequency regulation of wind and fire. DETAILED DESCRIPTION

[0078] The specific embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

[0079] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0080] The present invention provides a method for optimizing the unit output by considering the combined frequency regulation of wind and fire. Figure 1As shown, the method includes:

[0081] Step 101: Obtain the primary frequency regulation reserve capacity required by the power system;

[0082] Step 102 is for substituting the primary frequency regulation reserve capacity required by the power system into a pre-built unit output optimization model, solving the unit output optimization model, and obtaining the optimal output of the thermal power unit and the optimal output of the wind power unit in the power system;

[0083] The constraints of the pre-established unit output optimization model include: primary frequency regulation capability constraints;

[0084] The primary frequency regulation capability constraint condition is constructed based on the correspondence between the primary frequency regulation capability of the thermal power unit when participating in deep peak regulation and the output of the thermal power unit when participating in deep peak regulation, and the correspondence between the primary frequency regulation capability of the wind turbine unit and the output of the wind turbine unit.

[0085] In a specific embodiment of the present invention, a chaotic group teaching and learning optimization algorithm can be used to solve the unit output optimization model, thereby improving the practicality and accuracy of the solution results.

[0086] Specifically, the primary frequency regulation capacity constraint condition is determined as follows:

[0087]

[0088] In the above formula, ΔP Ti is the primary frequency regulation capability of the i-th thermal power unit in the power system when participating in deep peak regulation, ΔP Wj is the primary frequency regulation capability of the jth wind turbine in the power system, ΔP R is the primary frequency regulation reserve capacity required by the power system, i∈(1~N), N is the total number of thermal power units in the power system, j∈(1~M), M is the total number of wind turbines in the power system.

[0089] When thermal power units perform deep peak regulation, they inevitably cause a significant decrease in the primary frequency regulation capability of the power system. To understand the primary frequency regulation capability of thermal power units during deep peak regulation, a test was conducted on the operation of a 1000MW thermal power unit during deep peak regulation. The test showed that the peak regulation process of thermal power units can be divided into three stages: basic peak regulation, deep peak regulation without oil injection, and deep peak regulation with oil injection.

[0090] Typically, the boiler of a 1000MW high-parameter unit is designed to carry a base load and have a certain peak-shaving capability. The lower limit of the unit's basic peak-shaving capability is 40%-50% of the unit's rated power, and the lower limit of the unit's deep peak-shaving capability without oil injection is 35% of the unit's rated power.

[0091] The primary frequency regulation capability of a thermal power unit is achieved by varying the opening margin of the control valve. The higher the margin, the stronger the unit's frequency regulation capability. The opening margin of the control valve is controlled by the sliding pressure mode. When a thermal power unit is in deep peak regulation, its primary frequency regulation capability decreases to a certain extent due to factors such as heat storage, making it unable to fully meet the system's primary frequency regulation needs. Furthermore, the deeper the peak regulation depth, the weaker the primary frequency regulation capability. When a thermal power unit operates along the sliding pressure curve, its output varies across different load ranges, and its primary frequency regulation capability also varies. Therefore, the primary frequency regulation capability of a thermal power unit is a piecewise function of its current output.

[0092] When testing the operation of a 1000MW thermal power unit participating in deep peak regulation, the following results were obtained: Figure 2 The experimental results shown in the figure show that the larger the opening margin of the regulating valve is, the greater the primary frequency regulation capability of the thermal power unit is.

[0093] By changing the opening margin of the regulating valve to change the primary frequency regulation capacity of the thermal power unit, the output of the thermal power unit under each primary peak regulation capacity is recorded, and then the piecewise function of the primary frequency regulation capacity of the thermal power unit with respect to the output of the thermal power unit is obtained;

[0094] Where ΔP is determined by the following formula: Ti The output P of the i-th thermal power unit in the power system when participating in deep peak regulation Ti The corresponding relationship:

[0095]

[0096] To ensure that the power system has sufficient frequency regulation margin during deep peak regulation, the present invention considers the primary frequency regulation capability of wind turbines at different outputs. The primary frequency regulation constraint conditions of the unit output optimization model are constructed based on the primary frequency regulation capability of thermal power units participating in deep peak regulation and the primary frequency regulation capability of wind turbines. The optimal output of the wind turbines that meet the conditions is solved, and the output of the wind turbines is then adjusted to achieve the above-mentioned purpose.

[0097] The active power control strategy adopted by wind turbines during frequency regulation is achieved by coordinating the control of pitch angle and rotor kinetic energy, such as Figure 3 As shown in Figure 1, when the system generates frequency fluctuations due to power disturbances, the system determines that the output change command allocated to the wind turbine is optimized through the active power control strategy. At this time, since the response speed of the converter is faster than the pitch angle, the kinetic energy ΔE released by the rotor before the pitch angle control is:

[0098]

[0099] Where ω1 is the speed at which pitch angle control begins; ω0 is the initial speed of the wind turbine; and J is the inertia time constant of the wind turbine. When the wind turbine speed changes due to the release of kinetic energy from the rotor, this can be compensated by changing the pitch angle, thereby changing the energy captured by the wind turbine.

[0100] Compared to thermal power plants, wind turbines can provide rapid primary frequency regulation. However, because they cannot continuously participate in system frequency regulation, their primary frequency regulation time is relatively short, assuming 10 seconds. Furthermore, within this 10-second period, the impact of climate change on the wind turbine is negligible, assuming the wind energy captured by the turbine remains constant. When a system frequency disturbance occurs, the wind turbine output can be adjusted to a minimum of 10% of its rated value, at which point the wind turbine loses its primary frequency regulation capability.

[0101] The active reserve capacity of a wind turbine determines its primary frequency regulation capability. Specifically, a wind turbine's primary frequency regulation capability is related to wind speed, wind energy captured by the turbine, and load shedding level. When the system experiences frequency disturbances, not all wind turbines are capable of participating in primary frequency regulation, and the capabilities of participating wind turbines vary. Therefore, the primary frequency regulation capability of wind turbines under different operating conditions should be expressed separately.

[0102] Define the primary frequency regulation capability ΔP of the jth wind turbine generator set Wj as follows:

[0103] ΔP Wj =λ Wj ((ΔP Wj ) max ) (3)

[0104] Where: (ΔP Wj ) max is the maximum active reserve margin of the j-th wind turbine generator set, in MW; Wj is the decision variable for the minimum output of the j-th wind turbine group;

[0105] Among them, (ΔP Wj ) max =P Wj,max -P Wj =d Wj %P opt (v Wj ), P Wj,max is the maximum output of the j-th wind turbine in stable operation within 10s, in MW; P Wj is the output of the j-th wind turbine generator set, in MW; d Wj % is the load reduction level of the j-th wind turbine generator set in the power system; P opt (v Wj ) is the wind speed vWj The optimal captured wind power under the condition of MW, P opt (v Wj )>P Wj .

[0106] ρ is the atmospheric density; A j is the area swept by the wind rotor blades; C pmax for

[0107]

[0108] The maximum wind energy capture coefficient of the wind turbine; P WN,j is the rated output of the jth wind turbine in the power system.

[0109] Assuming that the regulation limit coefficient of the wind turbine participating in frequency regulation is 10%, and the output dead zone is set to 10% of the rated capacity, then

[0110] λ Wj = 0, the wind turbine has no active reserve capacity and no primary frequency regulation capability; when λ Wj =1, the wind turbine has sufficient active reserve capacity and can provide active support; when 0<λ Wj <1, although the wind turbine has active reserve capacity, if the 0.1P WN,j If the wind power output is adjusted, it may reach the minimum value, without active reserve capacity, which will harm the stable operation of the system. Therefore, when the wind power output is reduced to 0.1P WN When the frequency regulation stops, the wind turbine has no frequency regulation capability. It can be deduced that the ΔP Wj The output P of the jth wind turbine in the power system Wj The corresponding relationship:

[0111]

[0112] In the above formula, λ Wj is the minimum output decision variable of the j-th wind turbine in the power system, k 0j is the output coefficient of the j-th wind turbine in the power system, d Wj % is the load reduction level of the jth wind turbine generator set in the power system, v Wj is the wind speed that the j-th wind turbine in the power system is subjected to, P WN,j is the rated output of the jth wind turbine in the power system;

[0113] Wherein, the λ is determined as follows: Wj :

[0114]

[0115] In the above formula, P Wj is the output of the jth wind turbine in the power system;

[0116] Determine k as follows: 0j :

[0117]

[0118] In the above formula, C p,max is the maximum wind energy capture coefficient of wind turbines in the power system, A Wj is the area swept by the rotor blades of the j-th wind turbine in the power system, and ρ is the atmospheric density.

[0119] Specifically, the objective function of the pre-established unit output optimization model is determined as follows:

[0120]

[0121] In the above formula, f is the objective function value of the unit output optimization model, C Ti is the coal consumption of the i-th thermal power unit in the power system, g Ti is the pollutant emission of the i-th thermal power unit in the power system, F Wj is the wind curtailment of the j-th wind turbine in the power system, i∈(1~N), N is the total number of thermal power units in the power system, j∈(1~M), M is the total number of wind turbines in the power system;

[0122] Wherein, the C is determined as follows: Ti :

[0123]

[0124] In the above formula, a Ti is the first coal consumption characteristic coefficient of the i-th thermal power unit in the power system, b Ti is the second coal consumption characteristic coefficient of the i-th thermal power unit in the power system, c T * i is the third coal consumption characteristic coefficient of the i-th thermal power unit in the power system, P Ti is the output of the i-th thermal power unit in the power system when participating in deep peak regulation;

[0125] Determine the g as follows: Ti (P Ti ):

[0126]

[0127] In the above formula, V Tiis the pollutant emission of the i-th thermal power unit in the power system when operating at rated output, α Ti is the first pollutant emission characteristic coefficient of the i-th thermal power unit in the power system, β Ti is the second pollutant emission characteristic coefficient of the i-th thermal power unit in the power system, γ Ti is the third pollutant emission characteristic coefficient of the i-th thermal power unit in the power system, λ Ti is the fourth pollutant emission characteristic coefficient of the i-th thermal power unit in the power system;

[0128] Determine the F as follows: Wj :

[0129] F Wj =(P opt，j -P Wj )T s

[0130] In the above formula, P opt，j is the optimal wind power captured by the j-th wind turbine in the power system, T s is the wind speed sampling interval, P Wj is the output of the jth wind turbine in the power system;

[0131] Determine the P as follows: opt，j :

[0132]

[0133] In the above formula, k 0j is the output coefficient of the jth wind turbine in the power system, v Wj is the wind speed that the j-th wind turbine in the power system is subjected to, P WN,j is the rated output of the jth wind turbine in the power system.

[0134] Furthermore, the constraints of the pre-established unit output optimization model further include: power balance constraints, thermal power unit output constraints, and wind power unit output constraints;

[0135] The power balance constraint condition is determined as follows:

[0136]

[0137] In the above formula, P L is the total load of the power system;

[0138] The output constraint condition of the thermal power unit is determined as follows:

[0139] P Ti,min ≤P Ti ≤P Ti,max

[0140] In the above formula, P Ti,min is the lower limit of the output of the j-th wind turbine in the power system, P Ti,max is the output upper limit of the j-th wind turbine in the power system;

[0141] The output constraint condition of the wind turbine generator set is determined as follows:

[0142] P Wj,min ≤P Wj ≤P Wj,max

[0143] In the above formula, P Wj,min is the lower limit of the output of the i-th thermal power unit in the power system when participating in deep peak regulation, P Wj,max is the output upper limit of the i-th thermal power unit in the power system when participating in deep peak regulation.

[0144] The present invention provides a unit output optimization system considering wind-fire combined frequency regulation, such as Figure 4 As shown, the system includes:

[0145] An acquisition module is used to obtain the primary frequency regulation reserve capacity required by the power system;

[0146] A solution module is used to substitute the primary frequency regulation reserve capacity required by the power system into a pre-built unit output optimization model, solve the pre-built unit output optimization model, and obtain the optimal output of the thermal power units and the optimal output of the wind turbine units in the power system;

[0147] A regulating module, configured to regulate the output of a thermal power unit in a power system to be the optimal output of the thermal power unit, and the output of a wind power unit in a power system to be the optimal output of the wind power unit;

[0148] The constraints of the pre-established unit output optimization model include: primary frequency regulation capability constraints;

[0149] The primary frequency regulation capability constraint condition is constructed based on the correspondence between the primary frequency regulation capability of the thermal power unit when participating in deep peak regulation and the output of the thermal power unit when participating in deep peak regulation, and the correspondence between the primary frequency regulation capability of the wind turbine unit and the output of the wind turbine unit.

[0150] Specifically, the primary frequency regulation capacity constraint condition is determined as follows:

[0151]

[0152] In the above formula, ΔP Ti is the primary frequency regulation capability of the i-th thermal power unit in the power system when participating in deep peak regulation, ΔP Wjis the primary frequency regulation capability of the jth wind turbine in the power system, ΔP R is the primary frequency regulation reserve capacity required by the power system, i∈(1~N), N is the total number of thermal power units in the power system, j∈(1~M), M is the total number of wind turbines in the power system.

[0153] Furthermore, ΔP is determined as follows: Ti The output P of the i-th thermal power unit in the power system when participating in deep peak regulation Ti The corresponding relationship:

[0154]

[0155] Furthermore, the ΔP is determined as follows: Wj The output P of the jth wind turbine in the power system Wj The corresponding relationship:

[0156]

[0157] In the above formula, λ Wj is the minimum output decision variable of the j-th wind turbine in the power system, k 0j is the output coefficient of the j-th wind turbine in the power system, d Wj % is the load reduction level of the jth wind turbine generator set in the power system, v Wj is the wind speed that the j-th wind turbine in the power system is subjected to, P WN,j is the rated output of the jth wind turbine in the power system;

[0158] Wherein, the λ is determined as follows: Wj :

[0159]

[0160] In the above formula, P Wj is the output of the jth wind turbine in the power system;

[0161] Determine k as follows: 0j :

[0162]

[0163] In the above formula, C p,max is the maximum wind energy capture coefficient of wind turbines in the power system, A Wj is the area swept by the rotor blades of the j-th wind turbine in the power system, and ρ is the atmospheric density. Specifically, the objective function of the pre-established unit output optimization model is determined as follows:

[0164]

[0165] In the above formula, f is the objective function value of the unit output optimization model, C Ti is the coal consumption of the i-th thermal power unit in the power system, g Ti is the pollutant emission of the i-th thermal power unit in the power system, F Wj is the wind curtailment of the j-th wind turbine in the power system, i∈(1~N), N is the total number of thermal power units in the power system, j∈(1~M), M is the total number of wind turbines in the power system;

[0166] Wherein, the C is determined as follows: Ti :

[0167]

[0168] In the above formula, a Ti is the first coal consumption characteristic coefficient of the i-th thermal power unit in the power system, b Ti is the second coal consumption characteristic coefficient of the i-th thermal power unit in the power system, is the third coal consumption characteristic coefficient of the i-th thermal power unit in the power system, P Ti is the output of the i-th thermal power unit in the power system when participating in deep peak regulation;

[0169] Determine the g as follows: Ti (P Ti ):

[0170]

[0171] In the above formula, V Ti is the pollutant emission of the i-th thermal power unit in the power system when operating at rated output, α Ti is the first pollutant emission characteristic coefficient of the i-th thermal power unit in the power system, β Ti is the second pollutant emission characteristic coefficient of the i-th thermal power unit in the power system, γ Ti is the third pollutant emission characteristic coefficient of the i-th thermal power unit in the power system, λ Ti is the fourth pollutant emission characteristic coefficient of the i-th thermal power unit in the power system;

[0172] Determine the F as follows: Wj :

[0173] F Wj =(P opt，j -P Wj )T s

[0174] In the above formula, P opt，j is the optimal wind power captured by the j-th wind turbine in the power system, T sis the wind speed sampling interval, P Wj is the output of the jth wind turbine in the power system;

[0175] Determine the P as follows: opt，j :

[0176]

[0177] In the above formula, k 0j is the output coefficient of the jth wind turbine in the power system, v Wj is the wind speed that the j-th wind turbine in the power system is subjected to, P WN,j is the rated output of the jth wind turbine in the power system.

[0178] Furthermore, the constraints of the pre-established unit output optimization model further include: power balance constraints, thermal power unit output constraints, and wind power unit output constraints;

[0179] The power balance constraint condition is determined as follows:

[0180]

[0181] In the above formula, P L is the total load of the power system;

[0182] The output constraint condition of the thermal power unit is determined as follows:

[0183] P Ti,min ≤P Ti ≤P Ti,max

[0184] In the above formula, P Ti,min is the lower limit of the output of the j-th wind turbine in the power system, P Ti,max is the output upper limit of the j-th wind turbine in the power system;

[0185] The output constraint condition of the wind turbine generator set is determined as follows:

[0186] P Wj,min ≤P Wj ≤P Wj,max

[0187] In the above formula, P Wj,min is the lower limit of the output of the i-th thermal power unit in the power system when participating in deep peak regulation, P Wj,max is the output upper limit of the i-th thermal power unit in the power system when participating in deep peak regulation.

[0188] Those skilled in the art will appreciate that the embodiments of the present application can be provided as methods, systems, or computer program products. Therefore, the present application can adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the present application can adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to magnetic disk storage, CD-ROM, optical storage, etc.) that contain computer-usable program code.

[0189] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 a process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0190] These computer program instructions may also be stored in a computer readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 a process or multiple processes and / or boxes Figure 1 The function specified in one or more boxes.

[0191] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operational steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing the instructions executed on the computer or other programmable device for implementing the process. Figure 1 a process or multiple processes and / or boxes Figure 1 The steps for the function specified in one or more boxes.

[0192] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the field should understand that the specific implementation methods of the present invention can still be modified or replaced by equivalents. Any modification or equivalent replacement that does not depart from the spirit and scope of the present invention should be covered by the scope of protection of the claims of the present invention.

Claims

1. A method for optimizing unit output considering wind-fire combined frequency regulation, characterized in that: The method comprises: Obtain the primary frequency regulation reserve capacity required by the power system; Substituting the primary frequency regulation reserve capacity required by the power system into a pre-built unit output optimization model, solving the unit output optimization model, and obtaining the optimal output of the thermal power units and the optimal output of the wind power units in the power system; The constraints of the pre-built unit output optimization model include: primary frequency regulation capability constraints; The primary frequency regulation capacity constraint condition is constructed based on the corresponding relationship between the primary frequency regulation capacity of the thermal power unit when participating in deep peak regulation and the output of the thermal power unit when participating in deep peak regulation, and the corresponding relationship between the primary frequency regulation capacity of the wind turbine unit and the output of the wind turbine unit; The primary frequency regulation capacity constraint condition is determined as follows: In the above formula, ΔP Ti is the primary frequency regulation capability of the i-th thermal power unit in the power system when participating in deep peak regulation, ΔP Wj is the primary frequency regulation capability of the jth wind turbine in the power system, ΔP R is the primary frequency regulation reserve capacity required by the power system, i∈(1~N), N is the total number of thermal power units in the power system, j∈(1~M), M is the total number of wind turbines in the power system; Determine the ΔP as follows: Wj The output P of the jth wind turbine in the power system Wj The corresponding relationship: In the above formula, λ Wj is the minimum output decision variable of the j-th wind turbine in the power system, k 0j is the output coefficient of the j-th wind turbine in the power system, d Wj % is the load reduction level of the jth wind turbine generator set in the power system, v Wj is the wind speed that the j-th wind turbine in the power system is subjected to, P WN,j is the rated output of the jth wind turbine in the power system; Wherein, the λ is determined as follows: Wj : In the above formula, P Wj is the output of the jth wind turbine in the power system; Determine k as follows: 0j : In the above formula, C p,max is the maximum wind energy capture coefficient of wind turbines in the power system, A Wj is the area swept by the rotor blades of the j-th wind turbine in the power system, and ρ is the atmospheric density.

2. The method according to claim 1, wherein Determine ΔP as follows Ti The output P of the i-th thermal power unit in the power system when participating in deep peak regulation Ti The corresponding relationship:

3. The method according to claim 1, wherein The objective function of the pre-established unit output optimization model is determined as follows: In the above formula, f is the objective function value of the unit output optimization model, C Ti is the coal consumption of the i-th thermal power unit in the power system, g Ti is the pollutant emission of the i-th thermal power unit in the power system, F Wj is the wind curtailment of the j-th wind turbine in the power system, i∈(1~N), N is the total number of thermal power units in the power system, j∈(1~M), M is the total number of wind turbines in the power system; Wherein, the C is determined as follows: Ti : In the above formula, a Ti is the first coal consumption characteristic coefficient of the i-th thermal power unit in the power system, b Ti is the second coal consumption characteristic coefficient of the i-th thermal power unit in the power system, is the third coal consumption characteristic coefficient of the i-th thermal power unit in the power system, P Ti is the output of the i-th thermal power unit in the power system when participating in deep peak regulation; Determine the g as follows: Ti (P Ti ): In the above formula, V Ti is the pollutant emission of the i-th thermal power unit in the power system when operating at rated output, α Ti is the first pollutant emission characteristic coefficient of the i-th thermal power unit in the power system, β Ti is the second pollutant emission characteristic coefficient of the i-th thermal power unit in the power system, γ Ti is the third pollutant emission characteristic coefficient of the i-th thermal power unit in the power system, λ Ti is the fourth pollutant emission characteristic coefficient of the i-th thermal power unit in the power system; Determine the F as follows: Wj : F Wj =(P opt，j -P Wj )T s In the above formula, P opt，j is the optimal wind power captured by the j-th wind turbine in the power system, T s is the wind speed sampling interval, P Wj is the output of the jth wind turbine in the power system; Determine the P as follows: opt，j : In the above formula, k 0j is the output coefficient of the jth wind turbine in the power system, v Wj is the wind speed that the j-th wind turbine in the power system is subjected to, P WN,j is the rated output of the jth wind turbine in the power system.

4. The method according to claim 3, wherein The constraints of the pre-established unit output optimization model also include: power balance constraints, thermal power unit output constraints and wind power unit output constraints; The power balance constraint condition is determined as follows: In the above formula, P L is the total load of the power system; The output constraint condition of the thermal power unit is determined as follows: P Ti,min ≤P Ti ≤P Ti,max In the above formula, P Ti,min is the lower limit of the output of the j-th wind turbine in the power system, P Ti,max is the output upper limit of the j-th wind turbine in the power system; The output constraint condition of the wind turbine generator set is determined as follows: P Wj,min ≤P Wj ≤P Wj,max In the above formula, P Wj,min is the lower limit of the output of the i-th thermal power unit in the power system when participating in deep peak regulation, P Wj,max is the output upper limit of the i-th thermal power unit in the power system when participating in deep peak regulation.

5. A unit output optimization system considering wind and fire combined frequency regulation, characterized in that: The system comprises: An acquisition module is used to obtain the primary frequency regulation reserve capacity required by the power system; A solution module is used to substitute the primary frequency regulation reserve capacity required by the power system into a pre-built unit output optimization model, solve the unit output optimization model, and obtain the optimal output of the thermal power unit and the optimal output of the wind power unit in the power system; The constraints of the pre-established unit output optimization model include: primary frequency regulation capability constraints; The primary frequency regulation capacity constraint condition is constructed based on the corresponding relationship between the primary frequency regulation capacity of the thermal power unit when participating in deep peak regulation and the output of the thermal power unit when participating in deep peak regulation, and the corresponding relationship between the primary frequency regulation capacity of the wind turbine unit and the output of the wind turbine unit; The primary frequency regulation capacity constraint condition is determined as follows: In the above formula, ΔP Ti is the primary frequency regulation capability of the i-th thermal power unit in the power system when participating in deep peak regulation, ΔP Wj is the primary frequency regulation capability of the jth wind turbine in the power system, ΔP R is the primary frequency regulation reserve capacity required by the power system, i∈(1~N), N is the total number of thermal power units in the power system, j∈(1~M), M is the total number of wind turbines in the power system; Determine the ΔP as follows: Wj The output P of the jth wind turbine in the power system Wj The corresponding relationship: In the above formula, λ Wj is the minimum output decision variable of the j-th wind turbine in the power system, k 0j is the output coefficient of the j-th wind turbine in the power system, d Wj % is the load reduction level of the jth wind turbine generator set in the power system, v Wj is the wind speed that the j-th wind turbine in the power system is subjected to, P WN,j is the rated output of the jth wind turbine in the power system; Wherein, the λ is determined as follows: Wj : In the above formula, P Wj is the output of the jth wind turbine in the power system; Determine k as follows: 0j : In the above formula, C p,max is the maximum wind energy capture coefficient of wind turbines in the power system, A Wj is the area swept by the rotor blades of the j-th wind turbine in the power system, and ρ is the atmospheric density.

6. The system according to claim 5, wherein: Determine ΔP as follows Ti The output P of the i-th thermal power unit in the power system when participating in deep peak regulation Ti The corresponding relationship:

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