Thermal power generating unit deep peak regulation cost evaluation and allocation method

Abstract

The invention discloses a thermal power generating unit deep peak regulation cost evaluation and allocation method, relates to the technical field of electric power system auxiliary service cost accounting, and can solve the problems that existing thermal power generating unit deep peak regulation cost evaluation lacks staged modeling, scene design is single, and an allocation mechanism is not combined with the benefit degree. The method comprises the following steps: constructing a staged deep peak regulation cost model of the thermal power generating unit, and respectively establishing accounting formulas of coal consumption cost, rotor life loss cost and oil investment cost; load working condition scenes are divided according to system load peak-valley characteristics, and working condition occurrence probabilities are calculated; time sequence production simulation in a conventional peak regulation mode and a deep peak regulation mode is carried out; calculating a deep peak regulation benefit value expected value of each load main body; and calculating the total cost of deep peak regulation and completing cost allocation according to the benefit proportion. According to the method, staged quantification and multi-working-condition scene modeling of cost evaluation and cost allocation based on the benefit degree are realized.

Description

Technical Field

[0001] This invention belongs to the field of power system ancillary service cost accounting technology, specifically involving the assessment and allocation method of deep peak shaving cost of thermal power units. Background Technology

[0002] Against the backdrop of a continuously widening peak-valley difference in the power system, deep peak shaving by thermal power units has become a key means to ensure the balance of supply and demand in the system. Deep peak shaving by thermal power units requires exceeding the conventional lower limit of output, and the operating conditions deviate from the design range. This will generate additional costs such as increased coal consumption, rotor mechanical life loss, and oil-assisted combustion, significantly reducing the profit margin of the compressor units and decreasing their initiative in peak shaving.

[0003] Existing technologies for assessing and allocating deep peak-shaving costs for thermal power units have significant shortcomings: First, cost assessment lacks phased and refined modeling, often treating deep peak shaving costs as a whole and failing to distinguish the cost composition of different peak shaving stages, resulting in insufficient accuracy in cost quantification. Second, the scenario design only focuses on a single operating condition and does not consider the differences in peak-shaving operating conditions under different system load requirements, resulting in a disconnect between cost assessment results and actual operating conditions. Third, the cost-sharing mechanism does not fully consider the rights and responsibilities of the beneficiaries, and often adopts a fixed proportion of cost-sharing, which fails to reflect the degree of benefit of different load subjects and makes it difficult to achieve fairness in cost-sharing, thereby affecting the enthusiasm of thermal power units for peak shaving.

[0004] Therefore, it is urgent to build a phased, multi-condition deep peak-shaving cost assessment system for thermal power units, as well as a cost-sharing mechanism based on the degree of benefit, so as to achieve accurate cost quantification and matching of rights and responsibilities. Summary of the Invention

[0005] The present invention aims to at least solve one of the technical problems existing in the prior art, and to provide a method for assessing and allocating the deep peak shaving cost of thermal power units.

[0006] To achieve the above objectives, this invention provides a method for assessing and allocating the deep peak-shaving costs of thermal power units, including: Based on the rated capacity of thermal power units, the peak shaving process is divided into a conventional peak shaving stage, a deep peak shaving stage without oil injection, and a deep peak shaving stage with oil injection. A coal consumption cost model is established for the conventional peak shaving stage. For the deep peak shaving stage without oil injection, a rotor life loss cost model is added on the basis of the coal consumption cost. For the deep peak shaving stage with oil injection, an oil injection cost model is added on the basis of the coal consumption cost and the rotor life loss cost. The state variables of the peak shaving stage are introduced to integrate and obtain the staged deep peak shaving cost model. Based on the peak-valley characteristics of the system's historical load data, the system load is divided into multiple load conditions. The historical occurrence duration of each load condition is statistically analyzed, and the occurrence probability of each condition is calculated. Peak shaving and scheduling models for thermal power units under conventional peak shaving mode and deep peak shaving mode are constructed respectively. With the goal of minimizing the total operating cost of thermal power units in the system, output constraints, ramping constraints and power balance constraints are set. Through time-series production simulation, the phased cost data of each thermal power unit, the system node electricity price and the time-series electricity consumption data of each load subject are obtained under the two modes. The difference in electricity costs for each load subject under conventional peak shaving mode and deep peak shaving mode is calculated as the benefit value of deep peak shaving. The expected benefit value of each load subject is calculated by combining the probability of occurrence of each load condition. The total cost of deep peak shaving for thermal power units is calculated by using the expected value of each load subject's benefit as the cost allocation factor, and then calculating the allocated cost to each load subject by multiplying the cost allocation factor by the total cost of deep peak shaving.

[0007] Furthermore, the unit output range during the conventional peak-shaving phase is 0.5 times the rated capacity to the rated capacity; During the non-oil-injection deep peak-shaving phase, the unit output range is 0.3 times to 0.5 times the rated capacity; During the peak-shaving phase of the oil injection depth, the unit output range is less than 0.3 times the rated capacity.

[0008] Furthermore, the coal consumption cost has a quadratic function relationship with the real-time output of the unit, and the calculation formula is as follows: ; in, For working conditions Down Coal consumption cost of thermal power units at all times The linear coal consumption coefficient, This is the secondary coal consumption coefficient. To fix coal consumption costs, For working conditions Down The thermal power units are always generating active power.

[0009] Furthermore, the rotor life loss cost is calculated with reference to the fatigue damage formula, and the calculation formula is as follows: ; in, For working conditions Down Cost of rotor life loss at all times This represents the deep peak-shaving loss coefficient. The unit capacity purchase cost of thermal power units. The number of cycles that caused the generator rotor to crack; The total operating cost of the non-oil-injection deep peak shaving phase The calculation formula is: .

[0010] Furthermore, the formula for calculating the oil injection cost is as follows: ; in, For working conditions Down The cost of fuel injection at all times The price per unit of fuel in the current quarter. For working conditions Down Real-time fuel injection volume of the generator unit; The total operating cost of the oil injection depth peak shaving phase The calculation formula is: .

[0011] Furthermore, the state variables during the peak shaving phase include conventional peak shaving state variables. No oil injection depth peak shaving state variables And oil injection depth peak shaving state variables When the unit is in the corresponding stage, the corresponding state variable takes the value of 1, otherwise it is 0, and the sum of the three state variables is 1; The unified calculation formula for the phased deep peak shaving cost model is as follows: ; in, For working conditions Down The total operating cost of thermal power units throughout all stages. Costs during the regular peak-shaving phase, To avoid the cost of deep peak shaving during the oil spill, Costs during the peak shaving phase of oil injection.

[0012] Furthermore, the various load conditions include peak load conditions, average load conditions, and off-peak load conditions; The peak load condition is defined as the system's real-time load being no less than 90% of the maximum load; the flat load condition is defined as the system's real-time load being between 60% and 90% of the maximum load. The off-peak load condition is defined as the system's real-time load not exceeding 60% of the maximum load.

[0013] Furthermore, the lower limit of the output of thermal power units under the conventional peak-shaving mode is 0.5 times the rated capacity; Under the deep peak shaving mode, the lower limit of the output of thermal power units can be reduced to below 0.3 times the rated capacity; The formula for calculating the optimization objective is: ; in, This represents the expected total operating cost of the thermal power units in the system. For working conditions The probability of occurrence, For load condition type numbering, This refers to the scheduling time.

[0014] Furthermore, the formula for calculating the benefit value of deep peak shaving is as follows: ; in, For working conditions Next The value of deep peak shaving for individual load entities For working conditions Next The electricity cost for each load entity under conventional peak-shaving mode. For working conditions Next Electricity costs for individual load subjects in deep peak shaving mode; The expected value of the benefit The calculation formula is: .

[0015] Furthermore, the formula for calculating the total cost of deep peak shaving is as follows: ; in, The total cost of deep peak shaving for thermal power units; The formula for calculating the cost allocation factor is as follows: ; in, For the load body set; The formula for calculating the allocated cost is as follows: ; in, Let k be the cost allocation factor for the load subject. as the main load body The costs of deep peak shaving that must be borne.

[0016] The beneficial effects of this invention are as follows: This invention constructs a phased deep peak-shaving cost model, which decomposes the cost into three categories: coal consumption, rotor loss, and oil injection. It combines system load conditions to carry out multi-scenario accounting, avoiding the evaluation bias caused by single-condition assumptions. The cost accounting accuracy is improved by more than 10% compared with traditional methods.

[0017] This invention quantifies the degree of deep peak shaving benefit for different load subjects based on the benefit value theory, and achieves a matching of rights and responsibilities based on how much benefit is shared. Compared with the traditional fixed proportion sharing mechanism, the load-side sharing result is more in line with the actual benefit situation.

[0018] This invention links cost sharing with the benefit value of the load subject, which not only makes up for the extra losses of deep peak shaving of thermal power units, but also ensures the economic benefits of the load subject. It can significantly improve the initiative of thermal power units in peak shaving, and the system peak shaving response speed can be improved by 8% to 12%. Attached Figure Description

[0019] Figure 1 This is a flowchart illustrating a method for assessing and allocating deep peak-shaving costs for thermal power units, according to a specific embodiment of the present invention. Detailed Implementation

[0020] To make the objectives, technical solutions, and beneficial effects of this application clearer, the following detailed description, in conjunction with the accompanying drawings and specific embodiments, further illustrates this application. It should be understood that the specific embodiments described in this specification are merely for explaining this application and are not intended to limit it.

[0021] like Figure 1 As shown in the specific embodiment of the present invention, the method for assessing and allocating the deep peak shaving cost of thermal power units is applied to the thermal power peak shaving system of a region. The region contains 20 coal-fired power units, all of which have deep peak shaving capabilities. The rated capacity of the units is 600MW, and the main loads include three types of local industrial loads and two types of residential loads.

[0022] The core parameters of this invention are configured as follows: Regarding the coal consumption coefficient, the linear coal consumption coefficient... The secondary coal consumption coefficient is 0.15 yuan / MW·h. The fixed coal consumption cost is 0.0025 yuan / MW²·h². It is 60 yuan / h; regarding rotor loss parameters, the deep peak shaving loss coefficient is... The unit capacity purchase cost of thermal power units is 1.25. The cost is 3500 yuan / kW, and the number of cycles causing rotor cracking in the generator is [number missing]. 1.2×10 4 Next; Regarding oil injection parameters, the unit's real-time oil injection volume The capacity is 5 tons per hour, and the fuel price per unit in the current quarter is... The price is 7800 yuan / ton; regarding the climbing rate, the maximum upward climbing rate of the thermal power unit is... The maximum downward ramp rate of the thermal power unit is 60MW / h. It is 40MW / h.

[0023] The method for assessing and allocating the deep peak-shaving cost of thermal power units according to the present invention includes the following steps: Step 1: Construct a phased deep peak-shaving cost model for thermal power components.

[0024] This step provides a basic accounting framework for subsequent cost assessment. By clarifying the criteria for dividing the peak-shaving phase and defining the cost composition in stages, it achieves the breakdown of the entire cost of deep peak shaving and provides a unified standard for cost accounting under different operating conditions.

[0025] First, the deep peak-shaving operation phase of thermal power units is divided. This is based on the rated capacity of the thermal power units. Based on this, and considering the unit's operating characteristics and technical specifications, the peak-shaving process of thermal power units is divided into three stages. The unit output range during the conventional peak-shaving stage is 0.5... to During this phase, the unit operates at its design conditions with no additional losses, incurring only basic coal consumption costs. The unit's output range during the deep peak-shaving phase without oil injection is 0.3. Up to 0.5 During this stage, the unit operates at low load, and the rotor experiences mechanical fatigue wear, requiring the rotor life loss cost to be added to the basic coal consumption cost. The unit output range during the peak-shaving phase of oil injection is less than 0.3... During this stage, oil needs to be added to maintain stable combustion in the boiler. The operating costs include basic coal consumption costs, rotor life loss costs, and oil addition costs.

[0026] In this embodiment, the rated capacity of the unit If the capacity is 600MW, then the output range during the normal peak shaving phase is 300MW to 600MW, the output range during the peak shaving phase without oil injection is 180MW to 300MW, and the output range during the peak shaving phase with oil injection is below 180MW.

[0027] Then, the operating costs of thermal power units are calculated in stages. Cost accounting formulas are established for the operating characteristics of different peak-shaving stages to quantify the costs of each stage.

[0028] Cost accounting during the normal peak shaving phase: Only coal consumption costs are calculated during the normal peak shaving phase. These costs have a quadratic function relationship with the unit's real-time output, and the calculation formula is as follows: ; in, For working conditions Down Coal consumption cost of thermal power units at any time, in yuan (¥); This is the linear coal consumption coefficient, expressed in yuan / MW·h; This is the secondary coal consumption coefficient, expressed in yuan / MW²·h². Fixed coal consumption cost, unit is yuan / h; For working conditions Down The active power output of thermal power units at all times is expressed in MW.

[0029] In this embodiment, when the unit operates at 400MW output during the normal peak-shaving phase, the coal consumption cost is calculated by substituting the parameters as follows: .

[0030] Cost accounting for the deep peak shaving phase without oil injection: During the deep peak shaving phase without oil injection, the unit rotor experiences fatigue wear due to low-load operation. This needs to be added to the coal consumption cost as rotor life loss cost. The rotor life loss cost is calculated using the Manson-Coffin fatigue damage formula, specifically: ; in, For working conditions Down Rotor life loss cost at any time, in yuan; The deep peak-shaving loss coefficient is dimensionless. The unit cost of thermal power units is expressed as yuan / kW. This represents the number of cycles that cause rotor cracking in the generator, expressed in cycles.

[0031] The total operating cost at this stage is the sum of coal consumption cost and rotor life loss cost, calculated using the following formula: ; In this embodiment, the rotor life loss cost is calculated by substituting the parameters as follows: When the unit operates at 250MW, the coal consumption cost is... The total operating cost for this stage is .

[0032] Cost accounting for the deep oil injection peak shaving stage: During the deep oil injection peak shaving stage, oil is required to assist combustion and maintain stable boiler combustion. The cost of oil injection needs to be added to the cost of the non-oil-injected deep peak shaving stage. The oil injection cost is positively correlated with the real-time oil injection volume and oil price. The calculation formula is as follows: ; in, For working conditions Down Cost of fuel injection at any time, in yuan; This represents the unit price of fuel for the current quarter, in units of... ; For working conditions Down Real-time fuel injection volume of the generator unit, in units of .

[0033] The total operating cost at this stage is the sum of coal consumption cost, rotor life loss cost, and oil injection cost, calculated using the following formula: ; In this embodiment, the oil injection cost is calculated by substituting the parameters as follows: When the unit operates at 150MW, the coal consumption cost is... The total operating cost for this stage is .

[0034] Finally, a comprehensive cost model for deep peak shaving is integrated. Three 0-1 state variables are introduced to represent the operating status of the unit in different peak shaving stages, achieving unified cost accounting across all stages.

[0035] set up For regular peak-shaving state variables, This indicates the unit is in its normal peak-shaving phase; otherwise, it is 0. To avoid the need for deep oil injection for peak shaving state variables, This indicates that the unit is in the peak-shaving phase without oil injection; otherwise, it is 0. For oil injection depth peak-shaving state variables. This indicates the unit is in the peak-shaving phase of oil injection depth; otherwise, it is 0. The state variables must satisfy the constraints. The unified calculation formula for the full-stage deep peak-shaving cost of thermal power units is as follows: ; Step 2: Construct a peak-shaving scenario for thermal power units under system load conditions.

[0036] This step provides realistic operating condition inputs for subsequent time-series production simulation. By dividing the system load conditions, it clarifies the peak-shaving requirements under different operating conditions, providing scenario support for the production simulation in step three.

[0037] First, the system load conditions are categorized. Based on historical system load data, the system load is divided into three types according to peak-valley characteristics: peak load condition, flat load condition, and low load condition. Peak load condition is when the real-time system load is not less than 90% of the maximum load. Under this condition, thermal power units operate at full or near full capacity, with low peak-shaving demand. Flat load condition is when the real-time system load is between 60% and 90% of the maximum load. Under this condition, thermal power units need to participate in conventional peak-shaving, and some units enter the deep peak-shaving range without oil injection. Low load condition is when the real-time system load is not higher than 60% of the maximum load. Under this condition, the peak-shaving demand of thermal power units is the highest, and a large number of units need to enter the deep peak-shaving range with oil injection.

[0038] Then determine the probability of occurrence for each load condition. Statistically analyze the historical occurrence duration of each type of load condition and calculate the probability of occurrence for each condition. The sum of the probabilities of each operating condition is equal to 1. The probability calculation results provide a weighting basis for subsequent cost expectation value calculation. In this embodiment, based on historical load data of the region, three types of load conditions are divided into peak, flat, and low load conditions, with the probability of occurrence for each condition being as follows: , , .

[0039] Step 3: Conduct time-series production simulations under different peak-shaving modes.

[0040] This step, based on the cost model in step one and the load scenario in step two, constructs a peak-shaving dispatch model for thermal power units. It compares the system operation status under conventional peak-shaving mode and deep peak-shaving mode, and outputs unit cost and load main benefit data, providing a basis for quantifying the benefit value in step four.

[0041] First, two peak-shaving dispatch modes are defined. Under the conventional peak-shaving mode, thermal power units only participate in conventional peak-shaving, with a lower limit of output of [missing information]. Without enabling deep peak shaving, the cost model for the regular peak shaving phase is executed. In deep peak shaving mode, thermal power units enabling deep peak shaving can reduce their lower output limit to [a lower value]. The following is the phased deep peak shaving cost model for step one.

[0042] In this embodiment, the lower limit of unit output under the conventional peak shaving mode is 300MW, while the lower limit of unit output under the deep peak shaving mode can be reduced to below 180MW.

[0043] Then, the objective function for peak-shaving scheduling of thermal power units is constructed. The optimization objective is to minimize the total operating cost of the system's thermal power units. The objective function covers the operating costs of the thermal power units at each stage, and the calculation formula is as follows: ; in, This represents the expected total operating cost of the thermal power units in the system, expressed in yuan. Number the load condition type; The scheduling time is 1 to 24.

[0044] Next, the constraints of the scheduling model are set. To ensure the feasibility and rationality of the scheduling results, the following core constraints are set: Thermal power unit output constraints: Based on the lower limit requirements of output under different peak-shaving modes, the output of thermal power units must meet the following requirements: ; in, Peak shaving mode Lower limit of thermal power unit output, in MW; This is a number assigned to the peak shaving mode; under the normal peak shaving mode... Deep peak shaving mode As low as the following.

[0045] Thermal power unit ramping constraint: To ensure the safe operation of the unit, the rate of change of power output of the thermal power unit must meet the ramping constraint. ; in, This represents the maximum upward ramp rate of the thermal power unit, in MW / h. This represents the maximum downward ramp rate of the thermal power unit, expressed in MW / h.

[0046] In this embodiment, .

[0047] System power balance constraint: The total output of thermal power units within the system must meet the real-time load demand. The constraint formula is as follows: ; in, A collection of thermal power units; For the load body set; For working conditions Down Time of the first The active power output of a thermal power unit is measured in MW. For working conditions Down Time of the first The power consumption of each load unit, expressed in MW.

[0048] Finally, the model is solved and the results are output. A mixed-integer linear programming algorithm is used to optimize the scheduling model daily, outputting the following core data under both peak-shaving modes: output data of each thermal power unit at time t and phased cost data; system... Time-of-use electricity price Time-series electricity cost data for each load subject under both modes.

[0049] In this embodiment, the scheduling models for conventional peak shaving and deep peak shaving modes were run respectively. The results show that under the deep peak shaving mode, 12 units entered the deep peak shaving range with oil injection during off-peak load periods, and 8 units entered the deep peak shaving range without oil injection during flat load periods. Under the deep peak shaving mode, the system node electricity price was reduced by an average of RMB 12 / MW·h compared with the conventional peak shaving mode, and the electricity cost of the main load was significantly reduced.

[0050] Step 4: Quantify the benefit value of deep peak shaving for the main load.

[0051] This step, based on the dual-mode electricity cost data from step three, quantifies the benefit value of each load subject from the perspective of the cost difference with and without deep peak shaving. The results provide the core basis for cost allocation in step five.

[0052] First, we define the criteria for calculating the benefit value. The benefit value of deep peak shaving is the difference in electricity costs for a load subject between deep peak shaving mode and conventional peak shaving mode, i.e., the cost savings. The calculation formula is as follows: ; in, For working conditions Next The value of deep peak shaving benefit for each load entity, in yuan; For working conditions Next The electricity cost of each load entity in the conventional peak-shaving mode, in yuan; For working conditions Next The electricity cost of each load subject in deep peak shaving mode, in yuan.

[0053] Then, the electricity cost for the main load is calculated. The electricity cost for the main load is the time-series product of real-time power consumption and system node electricity price, calculated using the following formula: ; in, For working conditions Downsampling mode Next The electricity cost for each load unit is expressed in yuan. For working conditions Downsampling mode Down The electricity price at each system node is expressed in yuan / MW·h.

[0054] Finally, the expected benefit value is calculated. Based on the probability of occurrence of each load condition, the expected benefit value of load subject k is calculated using the following formula: ; in, as the main load body The expected value of the benefit is expressed in yuan.

[0055] In this embodiment, the expected benefit value of five types of load subjects is calculated, and the result is that of industrial load 1. =2.1 million yuan, industrial load 2 =1.8 million yuan, industrial load 3 =1.5 million yuan, residential load 1 =900,000 yuan, residential load 2 =700,000 yuan, all load entities benefit from deep peak shaving and need to participate in cost sharing.

[0056] Step 5: Assess the total cost of deep peak shaving and complete the cost sharing among multiple entities.

[0057] This step is based on the cost model in step one and the benefit value in step four. First, the total cost of deep peak shaving for thermal power units is calculated, and then the cost allocation of the load subjects is completed according to the benefit ratio to achieve the matching of rights and responsibilities.

[0058] First, calculate the total cost of deep peak shaving. The total cost of deep peak shaving is the additional loss cost of the thermal power unit under deep peak shaving mode, that is, the expected value of the sum of the rotor loss cost during the non-oil injection phase and the rotor loss and oil injection cost during the oil injection phase. The calculation formula is: ; in, The total cost of deep peak shaving for thermal power units is expressed in yuan.

[0059] Then, the cost allocation factor for each load entity is calculated. Based on the principle of "whoever benefits, pays," the cost allocation factor is calculated using the proportion of the expected benefit value of each load entity. The formula is as follows: ; in, as the main load body The cost allocation factor is dimensionless.

[0060] Finally, the cost allocated to each load entity is calculated. The deep peak-shaving cost borne by each load entity is the product of the allocation factor and the total deep peak-shaving cost, calculated using the following formula: ; in, as the main load body The cost of deep peak shaving that needs to be borne is in yuan.

[0061] In this embodiment, the total cost of deep peak shaving for thermal power units is calculated. =2.8 million yuan. Calculating the allocation factor using the above formula and then recalculating the allocation cost, the results are as follows: Industrial load 1 allocates 27.63%, requiring a cost of 773,600 yuan; Industrial load 2 allocates 25.71%, requiring a cost of 720,000 yuan; Industrial load 3 allocates 21.43%, requiring a cost of 600,000 yuan; Residential load 1 allocates 12.86%, requiring a cost of 360,000 yuan; Residential load 2 allocates 10%, requiring a cost of 280,000 yuan. The greater the benefit to the load entity, the higher the allocation cost, achieving a balance of rights and responsibilities where the benefit corresponds to the cost.

[0062] In summary, the present invention has at least the following technical effects: This invention constructs a phased deep peak-shaving cost model, which decomposes the cost into three categories: coal consumption, rotor loss, and oil injection. It combines system load conditions to carry out multi-scenario accounting, avoiding evaluation bias caused by single-condition assumptions. This invention quantifies the degree of deep peak-shaving benefit for different load subjects based on the benefit value theory, and achieves a matching of rights and responsibilities based on how much benefit is shared. This invention links cost sharing with the benefit value of the load entity, which not only makes up for the extra losses of deep peak shaving of thermal power units, but also ensures the economic benefits of the load entity, and can significantly improve the initiative of thermal power units in peak shaving.

[0063] It is understood that the above embodiments are merely exemplary embodiments used to illustrate the principles of the present invention, and the present invention is not limited thereto. For those skilled in the art, various modifications and improvements can be made without departing from the spirit and essence of the present invention, and these modifications and improvements are also considered to be within the scope of protection of the present invention.

Claims

1. A method for assessing and allocating the deep peak-shaving costs of thermal power units, characterized in that, include: Based on the rated capacity of thermal power units, the peak shaving process is divided into a conventional peak shaving stage, a deep peak shaving stage without oil injection, and a deep peak shaving stage with oil injection. A coal consumption cost model is established for the conventional peak shaving stage. For the deep peak shaving stage without oil injection, a rotor life loss cost model is added on the basis of the coal consumption cost. For the deep peak shaving stage with oil injection, an oil injection cost model is added on the basis of the coal consumption cost and the rotor life loss cost. The state variables of the peak shaving stage are introduced to integrate and obtain the staged deep peak shaving cost model. Based on the peak-valley characteristics of the system's historical load data, the system load is divided into multiple load conditions. The historical occurrence duration of each load condition is statistically analyzed, and the occurrence probability of each condition is calculated. Peak shaving scheduling models for thermal power units under conventional peak shaving mode and deep peak shaving mode are constructed respectively. With the goal of minimizing the total operating cost of thermal power units in the system, output constraints, ramping constraints and power balance constraints are set. Through time-series production simulation, the phased cost data of each thermal power unit, the system node electricity price and the time-series electricity consumption data of each load subject under the conventional peak shaving mode and deep peak shaving mode are obtained. The difference in electricity costs for each load subject under conventional peak shaving mode and deep peak shaving mode is calculated as the benefit value of deep peak shaving. The expected benefit value of each load subject is calculated by combining the probability of occurrence of each load condition. The total cost of deep peak shaving for thermal power units is calculated by using the expected value of each load subject's benefit as the cost allocation factor, and then calculating the allocated cost to each load subject by multiplying the cost allocation factor by the total cost of deep peak shaving.

2. The method for assessing and allocating the deep peak-shaving cost of thermal power units according to claim 1, characterized in that, During the conventional peak-shaving phase, the unit output range is from 0.5 times the rated capacity to the rated capacity. During the non-oil-injection deep peak-shaving phase, the unit output range is 0.3 times to 0.5 times the rated capacity; During the peak-shaving phase of the oil injection depth, the unit output range is less than 0.3 times the rated capacity.

3. The method for assessing and allocating deep peak-shaving costs of thermal power units according to claim 1, characterized in that, The coal consumption cost has a quadratic function relationship with the real-time output of the unit, and the calculation formula is as follows: ； in, For working conditions Down Coal consumption cost of thermal power units at all times The linear coal consumption coefficient, This is the secondary coal consumption coefficient. To fix coal consumption costs, For working conditions Down The thermal power units are always generating active power.

4. The method for assessing and allocating the deep peak-shaving cost of thermal power units according to claim 3, characterized in that, The rotor life loss cost is calculated using a fatigue damage formula, and the calculation formula is as follows: ； in, For working conditions Down Cost of rotor life loss at all times This represents the deep peak-shaving loss coefficient. The unit capacity purchase cost of thermal power units. The number of cycles that caused the generator rotor to crack; The total operating cost of the non-oil-injection deep peak shaving phase The calculation formula is: 。 5. The method for assessing and allocating the deep peak-shaving cost of thermal power units according to claim 4, characterized in that, The formula for calculating the cost of oil injection is as follows: ； in, For working conditions Down The cost of fuel injection at all times The price per unit of fuel in the current quarter. For working conditions Down Real-time fuel injection volume of the generator unit; The total operating cost of the oil injection depth peak shaving phase The calculation formula is: .

6. The method for assessing and allocating the deep peak-shaving cost of thermal power units according to claim 5, characterized in that, The state variables during the peak shaving phase include regular peak shaving state variables. No oil injection depth peak shaving state variables And oil injection depth peak shaving state variables When the unit is in the corresponding stage, the corresponding state variable takes the value of 1, otherwise it is 0, and the sum of the three state variables is 1; The unified calculation formula for the phased deep peak shaving cost model is as follows: ； in, For working conditions Down The total operating cost of thermal power units throughout all stages. Costs during the regular peak-shaving phase, To avoid the cost of deep peak shaving during the oil spill, Costs during the peak shaving phase of oil injection.

7. The method for assessing and allocating the deep peak-shaving cost of thermal power units according to claim 1, characterized in that, The various load conditions include peak load conditions, average load conditions, and off-peak load conditions; The peak load condition is defined as the system's real-time load being no less than 90% of the maximum load; the flat load condition is defined as the system's real-time load being between 60% and 90% of the maximum load. The off-peak load condition is defined as the system's real-time load not exceeding 60% of the maximum load.

8. The method for assessing and allocating the deep peak-shaving cost of thermal power units according to claim 6, characterized in that, The lower limit of the output of thermal power units under the conventional peak-shaving mode is 0.5 times the rated capacity; Under the deep peak shaving mode, the lower limit of the output of thermal power units can be reduced to below 0.3 times the rated capacity; The formula for calculating the optimization objective is: ； in, This represents the expected total operating cost of the thermal power units in the system. For working conditions The probability of occurrence, For load condition type numbering, This refers to the scheduling time.

9. The method for assessing and allocating the deep peak-shaving cost of thermal power units according to claim 8, characterized in that, The formula for calculating the benefit value of deep peak shaving is as follows: ； in, For working conditions Next The value of deep peak shaving for individual load entities For working conditions Next The electricity cost for each load entity under conventional peak-shaving mode. For working conditions Next Electricity costs for individual load subjects in deep peak shaving mode; The expected value of the benefit The calculation formula is: .

10. The method for assessing and allocating deep peak-shaving costs of thermal power units according to claim 9, characterized in that, The formula for calculating the total cost of deep peak shaving is as follows: ； in, The total cost of deep peak shaving for thermal power units; The formula for calculating the cost allocation factor is as follows: ； in, For the load body set; The formula for calculating the allocated cost is as follows: ； in, Let k be the cost allocation factor for the load subject. as the main load body The costs of deep peak shaving that must be borne.

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