Control method of self-provided power plant participating in frequency regulation

Abstract

The present invention relates to the technical field of power plant participation in frequency regulation, and is a control method for self-provided power plants to participate in frequency regulation, which includes constructing a load model for self-provided power plants to participate in frequency regulation, a capacity loss model for self-provided power plants of different industrial types in the frequency regulation process, a coal consumption loss model for self-provided power plants of the same industrial type in the frequency regulation process, and a variable load rate selection model, and solving the optimal control scheme based on the model. The present invention constructs a model that takes into account the industrial type of the self-provided power plant, the capacity loss in the frequency regulation process, the change in coal consumption in the frequency regulation process, and the rate selection model in the frequency regulation process. On this basis, the multi-objective optimization problem is solved to obtain the optimal strategy, which ensures the stability and reliability of the self-provided power plant participating in the frequency regulation work when connected to the grid; the present invention fully taps the frequency regulation potential of the self-provided power plant while maximizing the enthusiasm of the self-provided power plant manufacturers to participate in the frequency regulation work, and can significantly reduce the frequency regulation burden of the power grid.

Description

Technical Field

[0001] The invention relates to the technical field of power plant participation frequency regulation methods, and is a control method for a self-provided power plant to participate in frequency regulation work. Background Art

[0002] With the accelerated development of renewable energy and clean electricity, the installed capacity of new energy has increased year by year. In some regions, the installed capacity of new energy accounts for 32% of the total installed capacity of the entire network, and the output fluctuates significantly. In addition, the capacity of adjustable power sources (public thermal power and hydropower with storage capacity) in most regions of the country is limited.

[0003] In recent years, blockchain, electrolytic aluminum, polysilicon, steel, chemical and other related industries have been booming, and these large industrial users have established self-owned power plants to ensure their own electricity supply. In some parts of my country, the power generation load of such large industrial users accounts for 42.87% of the province's maximum load. Integrating domestic self-owned power plants with interruptible loads to carry out peak and frequency regulation of the power grid is an important measure to ensure the stable operation of DC transmission and solve the timeliness and intermittent shortcomings of renewable energy.

[0004] However, due to the special nature of self-provided power plants, they generate electricity to meet the production needs of their own units. For some industries, a large reduction in load will have an irreversible impact on the machines. Therefore, it is necessary to propose a judgment system and strategy method for the feasibility of self-provided power plants participating in frequency regulation, so as to further enhance the frequency regulation potential of self-provided power plants. Summary of the invention

[0005] The present invention provides a control method for a self-provided power plant to participate in frequency regulation, which overcomes the shortcomings of the above-mentioned prior art. On the premise of meeting the electricity demand of the enterprise, it can enhance the potential of the self-provided power plant to participate in frequency regulation and reduce the frequency regulation burden of the power grid.

[0006] The technical solution of the present invention is achieved through the following measures: A control method for a self-provided power plant to participate in frequency regulation work, comprising the following steps:

[0007] Step 1: Based on different industrial types and process characteristics, a load model for self-provided power plants to participate in frequency regulation is constructed to determine whether self-provided power plants can participate in frequency regulation and the priority of participating in frequency regulation;

[0008] Step 2: Based on different industrial types and process characteristics, a capacity loss model of self-provided power plants of different industrial types during the frequency regulation process is constructed to quantify the economic losses of self-provided power plants when participating in frequency regulation;

[0009] Step 3: Based on the characteristics of different frequency regulation operations, a coal consumption loss model and a variable load rate selection model for captive power plants of the same industrial type during frequency regulation are constructed;

[0010] Step 4: Based on the model constructed in steps 1 to 3, when the self-owned power plant participates in the frequency regulation process, the optimal regulation scheme is solved with the goal of minimizing the impact on the self-owned power plant and its industrial production, minimizing the change in coal consumption, maximizing the load change rate, and maximizing the regulation range.

[0011] The following are further optimizations and / or improvements to the above technical solutions:

[0012] In the above step 1, it is determined according to different industrial types whether the production load of the self-provided power plant of the industrial type can be interrupted. If it cannot be interrupted, the subsequent related processes are terminated. If it can be interrupted, a self-provided power plant participating in frequency regulation load model is established to determine its priority in participating in frequency regulation:

[0013]

[0014] R i =x1θ i +x2z i +x3α i

[0015] R i =x1θ i +x2τ i +x3α i

[0016] The load model of the self-provided power plant participating in frequency regulation is:

[0017]

[0018] In the formula, R i is the value coefficient of the priority of the units participating in frequency regulation; R i The larger the value, the higher the order of participating in frequency regulation. x1 is the proportion of interruption load, x2 is the proportion of interruption duration, and x3 is the weighted coefficient of surplus capacity proportion; L i is the interruptible load, in MW, t i is the interruptible time, in seconds, t is the total interruptible time; τ i is the ratio of interruptible time to the total interruptible time of frequency regulating units; α i is the production capacity surplus coefficient of the self-provided power plant, which is the coefficient given by the market after investigation; θ i is the ratio of interruptible load to total interruptible load of frequency regulating units; p i is the total surplus capacity per unit time (output without orders), and p is the total capacity per unit time.

[0019] In the above step 2, the capacity loss model is:

[0020]

[0021] Where Q is the profit per unit time when frequency modulation is not performed; ΔQ is the loss profit per unit time during frequency modulation; θ i is the ratio of interruptible load to total interruptible load of frequency regulating units; i is the capacity loss coefficient (the first case y i =0, the second case 0 <y i <1, the third case y i =1); p i is the total surplus capacity per unit time, p is the total capacity per unit time; γ is the contract price per unit product; δ is the cost required to produce a unit product excluding coal consumption; B is the amount of coal required to produce a unit product during the load change process, kg; c is the real-time market coal price; t1 and t2 are the start and end times of the frequency modulation process.

[0022] In the above step 3, according to different frequency modulation types, load change rates, and load change ranges, the coal consumption loss model is:

[0023]

[0024] Δb=b S -b R

[0025]

[0026] Where b R is the real-time coal consumption rate during the variable load process, g / (kW·h), b S is the rated coal consumption rate during the variable load process, g / (kW·h), Δb is the fluctuation value of the coal consumption rate, μ is the difference between the real-time variable load process and the standard average standard coal consumption rate, g / (kW·h), which is the average coal consumption per kW·h of electricity generated during the variable load process, L i is the total load of the power plant; t1 and t2 are the start and end times of the frequency regulation process.

[0027] In the above step 3, the variable load rate selection model is:

[0028]

[0029] Where ε is the economic loss, i is a different self-provided power plant, j is the variable load rate of the self-provided power plant; μ j is the additional consumption value of coal consumption under different variable load rates; Z i is the market capacity surplus coefficient; L i is the total load of the power plant, t1 and t2 are the start and end times of the frequency modulation process; c is the real-time market coal price; θ iis the ratio of interruptible load to total interruptible load of frequency regulating units; i is the industrial type; β is the average profit per unit product produced during the variable load process.

[0030] The variable load rate that minimizes ε is selected as the frequency regulation rate most suitable for the captive power plant.

[0031] The present invention constructs a rate selection model that takes into account the industrial type of the self-provided power plant, the capacity loss in the frequency modulation process, the change in coal consumption in the frequency modulation process, and the rate selection model in the frequency modulation process. On this basis, the multi-objective optimization problem is solved to obtain the optimal strategy, thereby ensuring the stability and reliability of the self-provided power plant's grid connection and participation in the frequency modulation work. The present invention fully taps the frequency modulation potential of the self-provided power plant while maximizing the enthusiasm of the self-provided power plant manufacturers to participate in the frequency modulation work, and can significantly reduce the frequency regulation burden of the power grid. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Attached Figure 1 This is a flow chart of the control method for a self-provided power plant participating in frequency regulation work described in the present invention. DETAILED DESCRIPTION

[0033] The present invention is not limited by the following embodiments, and specific implementation methods can be determined based on the technical solution of the present invention and actual conditions.

[0034] The present invention will be further described below in conjunction with embodiments:

[0035] Example: As shown in the attached Figure 1 As shown, the control method for the self-provided power plant to participate in frequency regulation work includes the following steps:

[0036] Step 1: Based on different industrial types and process characteristics, a load model for self-provided power plants to participate in frequency regulation is constructed to determine whether self-provided power plants can participate in frequency regulation and the priority of participating in frequency regulation;

[0037] Step 2: Based on different industrial types and process characteristics, a capacity loss model of self-provided power plants of different industrial types during the frequency regulation process is constructed to quantify the economic losses of self-provided power plants when participating in frequency regulation;

[0038] Step 3: Based on the characteristics of different frequency regulation operations, a coal consumption loss model and a variable load rate selection model for captive power plants of the same industrial type during frequency regulation are constructed;

[0039] Step 4: Based on the model constructed in steps 1 to 3, when the self-owned power plant participates in the frequency regulation process, the optimal regulation scheme is solved with the goal of minimizing the impact on the self-owned power plant and its industrial production, minimizing the change in coal consumption, maximizing the load change rate, and maximizing the regulation range.

[0040] In step 1, it is determined according to different industrial types whether the production load of the self-provided power plant of the industrial type can be interrupted. If it cannot be interrupted, the subsequent related processes are terminated. If it can be interrupted, a self-provided power plant participating in frequency regulation load model is established to determine its priority in participating in frequency regulation:

[0041]

[0042] R i =x1θ i +x2z i +x3α i

[0043] R i =x1θ i +x2τ i +x3α i

[0044] The load model of the self-provided power plant participating in frequency regulation is:

[0045]

[0046] In the formula, R i is the value coefficient of the priority of the units participating in frequency regulation; R i The larger the value, the higher the order of participating in frequency regulation. x1 is the proportion of interruption load, x2 is the proportion of interruption duration, and x3 is the weighted coefficient of surplus capacity proportion; L i is the interruptible load, in MW, t i is the interruptible time, in seconds, t is the total interruptible time; τ i is the ratio of interruptible time to the total interruptible time of frequency regulating units; α i is the production capacity surplus coefficient of the self-provided power plant, which is the coefficient given by the market after investigation; θ i is the ratio of interruptible load to total interruptible load of frequency regulating units; p i is the total surplus capacity per unit time (output without orders), and p is the total capacity per unit time.

[0047] In step 2, it is determined according to different industrial types whether the industrial type self-contained power plant can continue to carry out industrial production after load reduction, which is divided into three situations: (1) interrupting part of the load has no effect on the continued production of the power plant, and the proportion of capacity loss is the same as the proportion of interrupted load; (2) the power plant can continue partial production after interrupting part of the load, and the proportion of capacity loss is higher than the proportion of interrupted load; (3) the power plant cannot continue production after interrupting part of the load, and the capacity is completely lost. Considering the above conditions, the capacity loss model is constructed as follows:

[0048]

[0049] Where Q is the profit per unit time when frequency modulation is not performed; ΔQ is the loss profit per unit time during frequency modulation; θ i is the ratio of interruptible load to total interruptible load of frequency regulating units; i is the capacity loss coefficient (the first case y i =0, the second case 0 <y i <1, the third case y i =1); p i is the total surplus capacity per unit time, p is the total capacity per unit time; γ is the contract price per unit product; δ is the cost required to produce a unit product excluding coal consumption; B is the amount of coal required to produce a unit product during the load change process, kg; c is the real-time market coal price; t1 and t2 are the start and end times of the frequency modulation process.

[0050] In step 3, according to different frequency modulation types, load change rates, and load change ranges, the coal consumption loss model is:

[0051]

[0052] Δb=b S -b R

[0053]

[0054] Where b R is the real-time coal consumption rate during the variable load process, g / (kW·h), b S is the rated coal consumption rate during the variable load process, g / (kW·h), Δb is the fluctuation value of the coal consumption rate, μ is the difference between the real-time variable load process and the standard average standard coal consumption rate, g / (kW·h), which is the average coal consumption per kW·h of electricity generated during the variable load process, L i is the total load of the power plant; t1 and t2 are the start and end times of the frequency regulation process.

[0055] In step 3, the variable load rate selection model is:

[0056]

[0057] Where ε is the economic loss, i is a different self-provided power plant, j is the variable load rate of the self-provided power plant; μ j is the additional consumption value of coal consumption under different variable load rates; Z i is the market capacity surplus coefficient; L i is the total load of the power plant, t1 and t2 are the start and end times of the frequency modulation process; c is the real-time market coal price; θ iis the ratio of interruptible load to total interruptible load of frequency regulating units; i is the industrial type; β is the average profit per unit product produced during the variable load process.

[0058] (1) For industrial type y i =1, even if it loses part of its load, it can still continue production and generate corresponding profits, and the corresponding coal consumption fluctuation is less affected. Therefore, the solution with the fastest load change rate is selected as the frequency regulation option for the self-provided power plant.

[0059] (2) For industrial types 0﹤y i For a self-contained power plant of ﹤1, when a part of the load is lost, its industrial production work is affected, and it can only complete part of the production work and obtain some industrial semi-finished products. The product profit is limited. Therefore, it is necessary to quantify the relationship between the coal consumption rate and the product profit in the variable load process, and analyze this type of power plant through the construction of a model to obtain its optimal variable load rate.

[0060] (3) For industrial type y i = 0, if part of the load is lost, industrial production cannot continue and there is no corresponding product profit. Therefore, the variable load rate with the smallest average standard coal consumption difference is selected as the frequency regulation rate of this industrial type of self-contained power plant.

[0061] When there is a surplus of industrial capacity in the market for the captive power plants participating in frequency regulation, 0﹤Z i ﹤1; When the market is short of industrial capacity for frequency regulation captive power plants, 1﹤Z i ﹤2.

[0062] The variable load rate that minimizes ε is selected as the frequency regulation rate most suitable for the captive power plant.

[0063] The above technical features constitute the embodiments of the present invention, which have strong adaptability and implementation effect. Non-essential technical features can be added or reduced according to actual needs to meet the requirements of different situations.

Claims

1. A control method for a self-provided power plant to participate in frequency regulation, characterized in that The following steps are involved: Step 1: Construct a load model for self-provided power plants to participate in frequency regulation, and determine whether self-provided power plants can participate in frequency regulation and the priority of participating in frequency regulation; Step 2: Construct a capacity loss model for captive power plants of different industrial types during frequency regulation to quantify the economic losses of captive power plants when participating in frequency regulation; Step 3: Construct the coal consumption loss model and variable load rate selection model of the same industrial type of self-provided power plants during frequency regulation; Step 4: Based on the model constructed in steps 1 to 3, when the self-provided power plant participates in the frequency regulation process, the optimal regulation scheme is solved with the goal of minimizing the impact on the self-provided power plant and its industrial production, minimizing the change in coal consumption, maximizing the load change rate, and maximizing the regulation range; Among them, in step 1, the load model of the self-provided power plant participating in frequency regulation is: In the formula, R i is the value coefficient of the priority of the frequency regulation units; x1 is the proportion of interruption load; x2 is the proportion of interruption duration; x3 is the weighted coefficient of surplus capacity proportion; L i is the interruptible load; t i is the interruptible time; p i is the total surplus capacity per unit time; p is the total capacity per unit time; In step 2, the capacity loss model is: Where Q is the profit per unit time when frequency modulation is not performed; ΔQ is the loss profit per unit time during frequency modulation; θ i is the ratio of interruptible load to total interruptible load of frequency regulating units; i is the capacity loss coefficient; p i is the total surplus capacity per unit time, p is the total capacity per unit time; γ is the contract price per unit product; δ is the cost of producing a unit product excluding coal consumption; B is the amount of coal required to produce a unit product during the load change process; c is the real-time market coal price; t1 and t2 are the start and end times of the frequency modulation process; In step 3, according to different frequency modulation types, load change rates, and load change ranges, the coal consumption loss model is: Δb=b S -b R Where b R is the real-time coal consumption rate during the variable load process; b S is the rated coal consumption rate during the variable load process; Δb is the fluctuation value of the coal consumption rate; μ is the difference between the real-time variable load process and the standard average standard coal consumption rate; L i is the total load of the power plant; t1 and t2 are the start and end times of the frequency regulation process; In step 3, the variable load rate selection model is: In the formula, ε is the economic loss; i is a different self-provided power plant; j is the variable load rate of the self-provided power plant; μ j is the additional consumption value of coal consumption under different variable load rates; Z i is the market capacity surplus coefficient; L i is the total load of the power plant; t1 and t2 are the start and end times of the frequency modulation process; c is the real-time market coal price; θ i is the ratio of interruptible load to total interruptible load of frequency regulating units; i is the industrial type; β is the average profit per unit product produced during the variable load process.

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