CN107276122B - A decision-making method for peak shaving resources to adapt to large-scale renewable energy grid-connected - Google Patents

Abstract

The invention discloses a peak- _shaving resource _calling decision method suitable for large-scale renewable energy grid-connected. The time series predicted output P _W of the unit and the time series predicted output P _S of the solar generator set; determine the available peak shaving resources _Mi in the system, determine the adjustable measurement range of various peak shaving resources _Mi , the peak shaving capacity D _Mi and the corresponding peak shaving cost C _Mi , builds a mixed integer optimization model; obtains the optimized peaking resource calling sequence within a specific period. The invention constructs a mixed integer optimization model aiming at economy by establishing a technical economic model and a cost model of each peak regulation means, and obtains the best cost-effective peak regulation resource calling amount and calling sequence by solving the model, and adapts to the power system. The efficient consumption of renewable energy and the improvement of the peak shaving capacity of the power grid have good practical guiding significance and application value.

Description

A decision-making method for peak shaving resources to adapt to large-scale renewable energy grid-connected

technical field

The invention relates to the technical field of power simulation analysis, in particular to a peak-shaving resource calling decision method suitable for large-scale renewable energy grid-connected.

Background technique

With the large-scale development of renewable energy such as wind power and solar energy, its randomness and intermittency have an increasingly prominent impact on the safe and stable operation of the power system. The access of large-scale new energy sources has led to the increasing pressure of peak regulation faced by the system, especially the anti-peak regulation characteristics of wind power have significantly increased the difficulty of grid peak regulation.

Restricted by resource endowments, my country's power supply structure is dominated by coal-fired power with poor flexible adjustment capabilities, and the system's weak peak-shaving ability, resulting in limited consumption of renewable energy sources such as wind, solar, and water. The factors that affect wind power consumption can be classified into two aspects. One is the ability to absorb wind power, as long as the factors that determine the ability of wind power in a region include system regulation capacity, power transmission capacity, etc.; the second is the consumption level, which mainly refers to whether Making full use of the system's peak shaving resources, whether it can scientifically decide the amount and order of the limited peak shaving resources determines whether the maximum consumption of renewable energy can be achieved under the existing objective conditions.

At present, the invocation of peaking resources in my country is arbitrary, and the discretion of scheduling is very large, resulting in the gap between the invocation of various peaking resources and the actual demand, which is largely due to the lack of a reasonable decision-making process for the invocation of peaking resources. The scheduling of peak shaving resources in the scientific decision-making system needs to solve the following problems:

(1) How to accurately and scientifically define the available peak shaving resources in the system;

(2) How to carry out technical and economic modeling and peak-shaving cost modeling for various types of peak-shaving resources;

(3) How to construct a scientific and reasonable dispatching decision-making model to help dispatching agencies accurately realize the maximum consumption of renewable energy under the optimal economic situation.

However, there is currently no relevant appropriate model and method to describe the technical and economic characteristics of various peak shaving resources and quantify their peak shaving costs under a unified framework. sequential decision.

SUMMARY OF THE INVENTION

The invention proposes a peak-shaving resource calling decision-making system suitable for large-scale renewable energy grid-connected. Based on the mixed integer optimization method, the economical optimal peak-shaving resource calling capacity and calling sequence are obtained, and the access situation of large-scale renewable energy is improved. Reduce the rationality and scientificity of peak resource scheduling, and improve the renewable energy consumption capacity of the system. In order to solve the above-mentioned technical problems, the technical solution adopted in the present invention is to provide a peak-shaving resource invocation decision-making method suitable for large-scale renewable energy grid-connected, including the following steps:

Obtain the time-series load demand _PL in a specific time period in a specific area, and determine the peak-shaving demand A _t of the power dispatching agency in the specific area in a specific time period; determine the time-series predicted output _{P W} of the wind turbine and the time-series predicted output PS of the solar generating unit; determine the system The available peak shaving resources _Mi and their operating characteristics are determined according to the safety, stability and economic _constraints of the corresponding peak _shaving resources _Mi. The peak shaving cost C _Mi corresponding to the peak shaving resource _Mi is calculated, and a mixed integer optimization model is constructed; the optimal calling sequence of the peak shaving resource within a specific period is obtained; where i=1, 2, 3...n.

In the above method, the peak regulation demand A _t is specifically as follows:

结束时刻为t，结束时刻的时序负荷需求为且电力调度机构在时刻t₀预测到时刻t的调峰容量需求A_t为：Let the initial time of a specific period be t ₀ , and the sequential load demand at the initial time is

The end time is t, and the sequence load demand at the end time is And the peak shaving capacity demand A _t predicted by the power dispatching agency at time t ₀ to time t is:

In the formula, when A _t is positive, it represents the demand for peak adjustment, and when At _is negative, it represents the demand for peak reduction.

In the above method, the time series prediction output P _W of the wind turbine is specifically as follows:

表示该地区第g个风电场中第h_g台风机在该时刻预测风速下的理论出力；In the formula, a represents the number of wind farms in the area; b represents the number of wind turbines in the gth wind farm;

represents the theoretical output of the h _gth wind turbine in the gth wind farm in the region at the predicted wind speed at this moment;

The time-series prediction output P _S of the solar generator set is as follows:

表示该地区第g个太阳能电站中第h_g个光伏发电组件在该时刻预测光照强度下的理论出力。In the formula, c represents the number of solar power stations in the area; d represents the number of photovoltaic power generation modules in the gth solar power station;

Indicates the theoretical output of the h _gth photovoltaic power generation module in the gth solar power station in the region under the predicted light intensity at this moment.

In the above method, the peak shaving resources _Mi include: coal-fired power units, gas-fired power units, conventional hydropower units, pumped-storage units, nuclear power units, abandoning wind and solar, demand-side response, and output from tie lines.

In the above method, the adjustable measurement range of the various types of peak shaving resources _Mi , the peak shaving capacity D _Mi and the corresponding cost model C _Mi are specifically as follows:

Taking the coal-fired power unit as the peak shaving means M ₁ , the available peak-shaving capacity N _up of the coal-fired power unit is specifically as follows:

代表煤电机组当前出力；In the formula, Represents the maximum available output of the coal-fired power unit,

Represents the current output of coal-fired power units;

The available peak reduction capacity N _down of coal-fired power units is specifically as follows:

代表煤电机组最小可用出力；In the formula,

Represents the minimum available output of coal-fired power units;

The up-peak cost C _M1up of coal-fired power units is the fuel consumption cost, which is as follows:

即表示机组在

时出力的单位煤耗，其中P_M1,t0为初始时刻机组出力，

即初始时刻出力+上调峰容量，也就是当前时刻的出力；

表示t时刻调用的煤电机组上调峰容量；In the formula, β represents the coal consumption function of the coal-fired power unit,

means that the unit is

The unit coal consumption of the output at the time, among which P _{M1, t0} is the output of the unit at the initial time,

That is, the output at the initial moment + the peak capacity increase, that is, the output at the current moment;

Indicates the peak-shaving capacity of coal-fired power units called at time t;

The peak reduction cost C _M1down of coal-fired power units is the increased cost of unit coal consumption caused by the reduction of output, which is expressed by the following formula:

表示机组在

时出力的单位煤耗，

表示当前煤电机组出力，表示t时刻调用的煤电机组下调峰容量；In the formula, Indicates the unit coal consumption of the unit output at the initial moment;

Indicates that the unit is

The unit coal consumption of the time output,

Indicates the current output of coal-fired power units, Represents the peak-down capacity of coal-fired power units called at time t;

Taking the gas-fired unit as the peak-shaving means M ₂ , the available peak-shaving capacity N _up of the gas-fired unit is specifically as follows:

代表煤电机组最大可用出力，

代表煤电机组当前出力；In the formula,

Represents the maximum available output of the coal-fired power unit,

Represents the current output of coal-fired power units;

The available peak reduction capacity N _down of coal-fired power units is specifically as follows:

According to the actual dispatching demand, the gas-fired unit considers the different peak-shaving capabilities of LNG and ordinary gas, and the LNG is mainly set to start-stop peak-shaving. Therefore, the peak-shaving cost of the gas-fired unit is the fuel consumption cost, and the peak-shaving cost is 0;

The conventional hydropower unit is used as the peak shaving means M ₃ , and it is divided into the run-flow hydropower and the adjustable hydropower. Among them, the run-flow hydropower does not participate in the peak shaving, and the adjustable hydropower participates in the peak shaving during the dry season, and its peak shaving capacity is called. Reservoir water level constraints need to be met, as follows:

In the formula, W _to represents the initial water level of the reservoir, W _min represents the lowest water level of the reservoir, W _max represents the highest water level of the reservoir, and η is the conversion coefficient of power generation water;

The cost of conventional adjustable hydropower peaking is 0. When water is abandoned during peaking, the cost of peaking is as follows:

表示单位弃水成本，P_cur表示弃水量；In the formula,

Represents the unit cost of discarded water, and P _cur represents the amount of discarded water;

To use the pumped storage unit as the peak regulation means M ₄ , it needs to meet the water level constraints of the upper and lower reservoirs, as follows:

In the formula, W _to represents the initial water level of the reservoir, W _min represents the lowest water level of the reservoir, W _max represents the highest water level of the reservoir, and D _M4,t is the peak regulation capacity that the pumped storage unit is called to participate in;

The peak shaving cost of pumped storage units is represented by the pumping loss, and the peak shaving cost C _M4 is as follows:

C _M4 = (1-α)βD _M4,t

In the formula, α is the extraction conversion efficiency of the pumped-storage unit, and β is the rated unit coal consumption of the coal-fired power unit;

Taking the nuclear power unit as the peak shaving means M ₅ , the cost of increasing the peak shaving of the nuclear power unit is the fuel consumption cost, and the cost of reducing the peaking is 0; the specific formula of the peak shaving cost is as follows:

In the formula, ω represents the unit fuel cost of nuclear power, D _M5,t represents the peak capacity of nuclear power;

Abandoning wind and light is used as the peak shaving method M ₆ . When the peak shaving cannot be satisfied, the output of the abandoned wind and light is reduced in equal proportions, and the peak shaving cost is as follows:

为调用的弃风弃光调峰电量，λ为弃风弃光单位成本；In the formula,

It is the peak shaving electricity used for wind and light curtailment, and λ is the unit cost of curtailing wind and light;

The demand-side response is used as the peak shaving method M ₇ , and the peak shaving cost is as follows:

为调度需求侧响应资源参与的调峰容量，μ为需求侧响应单位调用成本；In the formula,

is the peak-shaving capacity of the dispatching demand-side response resource participation, and μ is the unit call cost of demand-side response;

The output of the tie line is used as the peak regulation method M ₈ , and the tie line outside the area is set as the first-level dispatchable line and the upper-level dispatching line. After the contact line plan is output, it is necessary to return the power that deviates from the plan at a suitable time later.

In the above method, the various types of peak shaving resources M _i need to meet the system peak shaving balance constraints, and the system peak shaving balance constraints are specifically as follows:

为各类调峰资源调用容量，

为风、光可再生能源发电预测出力偏差。in,

Call capacity for various peaking resources,

Predicted output deviation for wind and solar renewable energy power generation.

In the above method, the mixed integer optimization model includes three parts: decision variable, constraint condition and objective function, wherein the decision variable is the peak shaving capacity provided by various types of peak shaving resources _Mi in characteristic time periods; the constraint condition is the system shaving capacity. Peak balance constraints and security, stability and economic constraints; the objective function is the total cost of peak regulation.

In the above method, the objective function includes an objective function during peak-up regulation and an objective function during peak-down regulation;

The objective function of peak shaving time is the sum of coal power peak shaving fuel consumption cost, gas power generation fuel consumption cost, pumping storage loss cost, nuclear power fuel consumption cost and demand side response cost. The specific formula is as follows:

The objective function during peak reduction is the increase in coal consumption per unit of coal power output reduction, the peak regulation cost when conventional power units abandon water, the cost of pumping and storage losses, the sum of the cost of curtailing wind and light, and the cost of demand-side response, and other types of peaking resources. The cost is 0, expressed by the following formula:

The invention establishes a technical economic model and a cost model of each peak regulation means, and then builds a mixed integer optimization model aiming at economy, and obtains the best cost-effective peak regulation resource calling amount and calling sequence by solving the model. It has good practical guiding significance and application value to adapt to the efficient consumption of renewable energy and improve the peak regulation capacity of the power grid.

Description of drawings

Fig. 1 is the method flow chart provided by the present invention;

FIG. 2 is a flow chart of the specific implementation of the method provided by the present invention.

Detailed ways

The present invention will be described in detail below with reference to the specific embodiments and the accompanying drawings.

As shown in FIG. 1 , the present invention provides a decision-making method for peak shaving resources that is adapted to large-scale renewable energy grid-connected, including the following steps:

S1. Acquire the time-series load demand _PL in a specific time period in a specific area, and determine the peak regulation demand A _t of the power dispatching agency in the specific area in a specific time period.

结束时刻为t，结束时刻的时序负荷需求为

且电力调度机构在时刻t₀预测到时刻t的调峰容量需求A_t为：Assuming that the initial time of a specific period is t ₀ , the sequential load demand at the initial time is

The end time is t, and the sequence load demand at the end time is

And the peak shaving capacity demand A _t predicted by the power dispatching agency at time t ₀ to time t is:

In the formula, when A _t is positive, it represents the demand for peak adjustment, and when At _is negative, it represents the demand for peak reduction.

S2. Determine the time series predicted output P _W of the wind turbine and the time series predicted output P _S of the solar energy generator.

The time series predicted output P _W of the wind turbine is as follows:

表示该地区第g个风电场中第h_g台风机在该时刻预测风速下的理论出力。In the formula, a represents the number of wind farms in the area; b represents the number of wind turbines in the gth wind farm;

Indicates the theoretical output of the h _gth wind turbine in the gth wind farm in the region at the predicted wind speed at this moment.

The time-series prediction output P _S of the solar generator set is as follows:

表示该地区第g个太阳能电站中第h_g个光伏发电组件在该时刻预测光照强度下的理论出力。In the formula, c represents the number of solar power stations in the area; d represents the number of photovoltaic power generation modules in the gth solar power station;

Indicates the theoretical output of the h _gth photovoltaic power generation module in the gth solar power station in the region under the predicted light intensity at this moment.

S3. Determine the available peak shaving resources _Mi and its operating characteristics in the system, and determine the adjustable measurement range and peak shaving capacity D _Mi of various peak shaving resources _Mi according to the safety, stability and economic constraints of the corresponding peak shaving resources _Mi , and the peak shaving cost C _Mi corresponding to each peak shaving resource _Mi (where i=1, 2, 3...n), and build a mixed integer optimization model. Wake up the optimization model to obtain the calling sequence and calling amount of peak shaving resources.

In this embodiment, the peak shaving resources involved in peak shaving include but are not limited to coal-fired power units, gas-fired units, conventional hydropower units, pumped storage units, nuclear power units, abandoned wind and solar power, demand-side response, and tie line output, and correspond to The safety, stability and economic constraints are respectively peak shaving balance constraints, output constraints, reservoir dynamic capacity constraints, wind and solar curtailment constraints, unit ramping power constraints, unit continuous start-stop constraints and actual dispatch operation constraints.

First of all, determine the time series theoretical output _PF of wind turbines in a specific area, the operating characteristics of conventional power generators, and the time series load demand _PL , among which,

The time series theoretical output P _F of the wind turbine is as follows:

表示该地区第g个风电场中第h_g台风机在该时刻风速条件下的理论出力。In the formula, a represents the number of wind farms in the area; b represents the number of wind turbines in the gth wind farm;

Indicates the theoretical output of the h _gth wind turbine in the gth wind farm in the region under the wind speed conditions at this moment.

The time series load demand _PL is calculated based on the historical time series load curve of the corresponding time period in the region and the predicted load peak value of the research time period, and the specific formula is as follows:

是历史负荷，K_f是研究时段的预测的负荷峰值，K_h是历史负荷峰值。In the formula,

is the historical load, K _f is the predicted peak load during the study period, and K _h is the historical peak load.

The common operating characteristics of the above-mentioned types of peak shaving resources in the system mainly include parameters such as the maximum available output P _C,max , the minimum available output P _C,min , and the ramp rate of the unit; the sum of the maximum available output of conventional power units should be greater than the load and the maximum value of the sum of the planned outgoing power of the tie line, and a certain positive reserve capacity is reserved, the maximum available output P _C,max of the conventional power unit in this area is shown in the following formula:

In the formula, I represents the number of conventional power units in the area, P _Ci,max represents the maximum available technical output of the ith conventional unit, P _L(t) represents the load power in the area at time t, P _t,plan (t) Represents the planned outgoing power of the tie line at time t, and R ₊ represents the positive reserve capacity. It should be noted that conventional power sources refer to power sources other than wind power and solar power, that is, all resources in peak shaving resources except wind, light and load-side response.

1. Taking the coal-fired power unit as the peak shaving means M ₁ , the available peak-shaving capacity N _up of the coal-fired power unit is specifically as follows:

代表煤电机组最大可用出力，

代表煤电机组当前出力。In the formula,

Represents the maximum available output of the coal-fired power unit,

Represents the current output of the coal-fired power unit.

The available peak reduction capacity N _down of coal-fired power units is specifically as follows:

In the formula, P _M1,min represents the minimum available output of the coal-fired power unit. The above-mentioned peak up-regulation capability and peak down-regulation capability represent an adjustable measurement range.

According to the actual scheduling requirements, the coal power generators are composed of the first-level scheduling unit and the upper-level scheduling unit. The current-level scheduling unit is set to be called with high priority, and the upper-level scheduling unit is set to be unschedulable or low-priority calling. Considering the difference between the denitrification load and the load for stable combustion with oil input, the coal-fired power unit should reasonably set the peak-shaving cost, which is shown in the priority of reducing the coal-fired power unit to the de-nitrification load in the peak-down calling sequence, while the load of oil input and stable combustion is used as an unconventional adjustment method. , the peak-up cost C _M1up of coal-fired power units is the fuel consumption cost, which is as follows:

时出力的单位煤耗，其中P_M1,t0为初始时刻机组出力，

即初始时刻出力+上调峰容量，也就是当前时刻的出力；

表示t时刻调用的煤电机组上调峰容量。In the formula, β represents the coal consumption function of the coal-fired power unit, means that the unit is

The unit coal consumption of the output at the time, among which P _{M1, t0} is the output of the unit at the initial time,

That is, the output at the initial moment + the peak capacity increase, that is, the output at the current moment;

Indicates the up-peak capacity of the coal-fired power unit called at time t.

The peak reduction cost C _M1down of coal-fired power units is the increased cost of unit coal consumption caused by the reduction of output, which is expressed by the following formula:

表示机组在初始时刻出力的单位煤耗；

表示机组在时出力的单位煤耗，

表示当前煤电机组出力，

表示t时刻调用的煤电机组下调峰容量。In the formula,

Indicates the unit coal consumption of the unit output at the initial moment;

Indicates that the unit is The unit coal consumption of the time output,

Indicates the current output of coal-fired power units,

Indicates the peak-down capacity of coal-fired power units called at time t.

2. Taking the gas generating unit as the peak shaving means M ₂ , the available peak shaving capability N _up of the gas generating unit is as follows:

代表煤电机组最大可用出力，

代表煤电机组当前出力。In the formula,

Represents the maximum available output of the coal-fired power unit,

Represents the current output of the coal-fired power unit.

The available peak reduction capacity N _down of coal-fired power units is specifically as follows:

According to the actual scheduling requirements, the gas generating units consider the different peak shaving capabilities of LNG (Liquefied Nature Gas, liquefied natural gas) and ordinary gas.

The up-peak cost of gas-fired units is the fuel consumption cost, and the down-peak cost is 0.

3. The conventional hydropower unit is used as the peak shaving means M ₃ , which can be divided into run-flow hydropower and adjustable hydropower. Among them, the run-flow hydropower does not participate in the peak shaving, and the adjustable hydropower participates in the peak shaving during the dry season. The peak shaving capacity D _M3,t needs to be called. Satisfy the reservoir water level constraints, as follows:

In the formula, _{Wto represents the initial water level of the reservoir, Wmin represents} the lowest water level of the reservoir, _Wmax represents the highest water level of the reservoir, and η is the conversion coefficient of power generation water.

The conventional adjustable hydropower peaking cost is 0, and the peaking cost is as follows:

表示单位弃水成本，P_cur表示弃水量。In the formula,

Indicates the unit cost of discarded water, and P _cur represents the amount of discarded water.

4. The pumped storage unit is used as the peak shaving means M ₄ , which is similar to conventional hydropower, and needs to meet the water level constraints of the upper and lower reservoirs, as follows:

In the formula, W _to represents the initial water level of the reservoir, W _min represents the lowest water level of the reservoir, W _max represents the highest water level of the reservoir, and D _M4,t is the peak regulation capacity that the pumped storage unit is called to participate in.

The pumped storage unit has two working conditions of pumping and power generation, and the adjustable range is from the full pumping state to the full power generation state. The peak shaving cost is 0, and the peak shaving cost C _M4 is as follows:

C _M4 = (1-α)βD _M4,t

In the formula, α is the extraction conversion efficiency of the pumped-storage unit, and β is the rated unit coal consumption of the coal-fired power unit.

5. The nuclear power unit is used as a peak shaving method M ₅ , the cost of peak shaving of nuclear power units is the cost of fuel consumption, and the cost of peak shaving represents the reduction of nuclear power output, and the cost of peak shaving is 0, but the consideration of peak shaving of nuclear power units needs to be prepared for a long time in advance; The specific formula for the peak adjustment cost is as follows:

In the formula, ω represents the unit fuel cost of nuclear power, and D _M5,t represents the peak capacity of nuclear power.

6. Abandoning wind and light as the peak shaving means M ₆ , when the peak shaving cannot be satisfied, the output of the abandoned wind and light shall be reduced in equal proportions, and the specific peak shaving cost is as follows:

为调用的弃风弃光调峰电量，λ为弃风弃光单位成本。In the formula,

It is the peak shaving power of wind and light curtailment called, and λ is the unit cost of curtailing wind and light.

7. The demand-side response is used as the peak regulation method M ₇ , and the resource cost of calling the demand-side response is as follows:

为调度需求侧响应资源参与的调峰容量，μ为需求侧响应单位调用成本。In the formula,

is the peak-shaving capacity of the scheduling demand-side response resource participation, and μ is the unit call cost of the demand-side response.

8. Take the output of the tie line as the peak regulation method M ₈ , and set the tie line outside the district as the first-level dispatchable line and the upper-level dispatch line. The upper-level dispatch line is set as unschedulable or low-priority call, and the load support of the tie line is considered. The follow-up "return power" effect, that is, after adjusting the tie line at a certain time to plan the output, it is necessary to return the power that deviates from the plan at a suitable time later.

The above-mentioned various types of peak shaving resources Mi need to consider safety, stability and economic constraints, and also need to meet the system peak shaving balance constraints to ensure the balance of power supply and demand in the system. The system peak shaving balance constraints are as follows:

为各类调峰资源调用容量，为风、光可再生能源发电预测出力偏差，A_t为调峰需求。in,

Call capacity for various peaking resources, is the predicted output deviation of wind and solar renewable energy power generation, and A _t is the demand for peak regulation.

The mixed integer optimization model consists of three parts: decision variables, constraints and objective functions. The decision variables are the peak shaving capacity provided by various peak shaving resources _Mi in characteristic time periods; the constraints are the above-mentioned system peak shaving balance constraints and safety Stability and economic constraints. The objective function is the total cost of system peak shaving, and the objective function includes the objective function when peaking is increased and the objective function is when peaking is reduced. The sum of cost and demand-side response cost is as follows:

The objective function during peak reduction is the increase in coal consumption per unit of coal power output reduction, the peak regulation cost when conventional power units abandon water, the cost of pumping and storage losses, the sum of the cost of curtailing wind and light, and the cost of demand-side response, and other types of peaking resources. The cost is 0, expressed by the following formula:

S4. Sort and output the peak shaving cost C _Mi and peak shaving capacity of calling various types of peak shaving resources _Mi in ascending order, and obtain the optimal calling sequence of peak shaving resources within a specific period of time. The one with the smallest calling cost is the optimal one. Peak shaving resources.

The specific implementation steps of this embodiment are described below, as shown in Figure 2, including the following steps:

S11. Determine the peak shaving demand A _t of the power dispatching agency in a specific area in a specific time period.

S12. Obtain the time series theoretical output _{P W} of the wind turbine generator set, the time series predicted output power PS of the solar generator set, and the operation characteristics of the conventional power generator set and the time series load demand _PL .

S13. Determine available peak shaving resources _Mi in the system.

S14. Determine the operation characteristics of each peaking resource M _i , determine the adjustable measurement range of each peaking resource M _i according to the scheduling requirement, and construct a corresponding cost model.

S15. Determine the security, stability and economic constraints that need to be met when each peak shaving resource _Mi is called.

S16: Determine the peak shaving costs C _Mi of various types of peak shaving resources _Mi , and determine the objective functions of the peak-up and peak-down periods respectively.

S17. Build a mixed integer optimization model.

S18. Solve the model, and output the peak shaving cost C _Mi and peak shaving capacity of various types of peak shaving resources _Mi in descending order.

S19. End

The method provided by the invention is simple and clear to implement, establishes a technical and economic model and a cost model for each peak regulation means, and then builds a mixed integer optimization model aiming at economy, and obtains the best cost-effective peak regulation resource call amount and The calling sequence has good practical guiding significance and application value for the power system to adapt to the efficient consumption of renewable energy and to improve the peak regulation capacity of the power grid.

The present invention is not limited to the above-mentioned best embodiment, and anyone should know that structural changes made under the inspiration of the present invention, and all technical solutions that are the same or similar to the present invention, fall within the protection scope of the present invention.

Claims (4)

1. The peak-shaving resource calling decision method suitable for large-scale renewable energy grid connection is characterized by comprising the following steps of:

acquiring time sequence load demand P in specific time period of specific area_LDetermining the peak load regulation demand A of the power dispatching mechanism in the specific area in the specific time period_t(ii) a Determining a time sequence predicted output P of a wind turbine_WAnd the time sequence predicted output P of the solar generator set_S(ii) a Determining available peak shaver resources M in system_iAnd its operating characteristics, according to the corresponding peak shaving resource M_iThe safety, stability and economic constraint conditions of the method determine various peak regulation resources M_iAdjustable measuring range and peak-load capacity D_MiAnd each peak shaving resource M_iCorresponding peak shaver cost C_MiConstructing a mixed integer optimization model; obtaining an optimized peak-shaving resource calling sequence in a specific time period; wherein i is 1,2,3.. n;

the peak shaving requirement A_tSpecifically, the following formula:

let the initial time of a particular period be t₀The time sequence load requirement of the initial time is

T at the end time, the time sequence load requirement of the end time is

And the power dispatching mechanism is at the time t₀Predicting a peak shaving capacity demand A at time t_tComprises the following steps:

in the formula, when A_tIs positive, representing a demand for up-peaking, when A_tWhen negative, it represents a down-regulation peak demand;

the time sequence predicted output P of the wind turbine generator_WSpecifically, the following formula:

in the formula, a represents the number of wind power plants in the area; b represents the number of fans in the g wind power plant;

represents the h-th wind power plant in the g-th wind power plant of the area_gThe theoretical output of the platform fan under the wind speed is predicted in a specific time period;

time sequence predicted output P of solar generator set_SSpecifically, the following formula:

in the formula, c represents the number of solar power stations in the area; d represents the number of photovoltaic power generation components in the g-th solar power station;indicates the ith solar power station in the area_gThe theoretical output of each photovoltaic power generation assembly under the illumination intensity is predicted in a specific time period;

the peak shaving resource M_iThe method comprises the following steps: the system comprises a coal-electricity unit, a gas-fired unit, a conventional hydroelectric unit, a pumped storage unit, a nuclear power unit, a wind and light abandoning unit, a demand side response and a tie line output;

the peak shaving information of each kindSource M_iAdjustable measuring range and peak-load capacity D_MiAnd corresponding cost model C_MiSpecifically, the following formula:

using coal electric machine set as peak regulation means M₁Available peak regulation capacity N of coal-electric machine set_upSpecifically, the formula is as follows:

in the formula,

represents the maximum available output of the coal-electric machine set,

representing the current output of the coal-electricity unit;

available down-peak regulation capacity N of coal-electric unit_downSpecifically, the formula is as follows:

in the formula,

representing the minimum available output of the coal-electricity unit;

peak-shaving cost C of coal-electric machine set_M1upIs the fuel consumption cost, which is specifically given by the following formula:

in the formula,namely to indicate the unit at

Specific coal consumption per hour of output, where P_M1,t0The output of the machine set at the initial moment,

namely, the output at the initial moment and the peak-load capacity, namely the output at the current moment;

representing the peak shaving capacity of the coal-electric unit called at the time t;

peak reduction cost C of coal-electric unit_M1downThe cost per unit coal consumption is increased due to the low pressure output, and is represented by the following formula:

in the formula,

the unit coal consumption of the unit at the initial moment is represented;

indicating the units in

The unit coal consumption of the hour-output force,

the output of the current coal-electric machine set is shown,

the peak reduction capacity of the coal-electric unit called at the time t is represented;

using gas turbine as peak regulation means M₂The available peak-shaving capacity N of the gas engine set_upSpecifically, the formula is as follows:

in the formula,

represents the maximum available output of the coal-electric machine set,

representing the current output of the coal-electricity unit;

available down-peak regulation capacity N of coal-electric unit_downSpecifically, the formula is as follows:

according to the actual scheduling requirement, the gas turbine set considers different peak regulation capacities of liquefied natural gas and common gas, the liquefied natural gas is mainly set to be in a start-stop peak regulation mode, so that the peak regulation cost of the gas turbine set is the fuel consumption cost, and the peak regulation cost is 0;

taking a conventional hydroelectric generating set as a peak regulation means M₃The method is divided into runoff hydropower and adjustable hydropower, wherein the runoff hydropower does not participate in peak regulation, the adjustable hydropower participates in peak regulation in the dry season, and the peak regulation capacity D is called_M3,tReservoir water level constraints need to be met, and the method specifically comprises the following steps:

in the formula, W_toIndicating the initial water level of the reservoir, W_minIndicating the lowest water level of the reservoir, W_maxRepresenting the highest water level of the reservoir, wherein η is a conversion coefficient of the generated water quantity;

the conventional adjustable hydroelectric peak-regulation cost is 0, and when the peak-regulation cost is lowered and water abandon occurs, the peak-regulation cost is specifically as follows:

in the formula,

represents the unit water disposal cost, P_curRepresenting the water abandon amount;

the pumped storage unit is used as a peak regulation means M₄The upper and lower reservoir water level constraints need to be satisfied, as follows:

in the formula, W_toIndicating the initial water level of the reservoir, W_minIndicating the lowest water level of the reservoir, W_maxIndicating the highest water level of the reservoir, D_M4,tThe peak regulation capacity participated by the pumped storage unit is called;

the peak regulation cost of the pumped storage unit is expressed by pumping loss, and the peak regulation cost C_M4Specifically, the following formula:

C_M4＝(1-α)βD_M4,t

in the formula, α is the pumping conversion efficiency of the pump storage unit, and β is the rated unit coal consumption of the coal-electric unit;

nuclear power unit is taken as peak regulation means M₅The peak-load adjustment cost of the nuclear power unit is the cost of fuel consumption, and the peak-load adjustment cost is 0; the specific formula of the peak-up cost is as follows:

where ω represents the nuclear power unit fuel cost, D_M5,tRepresenting the nuclear power peak-shaving capacity;

the abandoned wind and abandoned light is used as a peak regulation means M₆When the peak regulation can not be met, the wind and light are abandoned and the power is reduced in equal proportion to operate, and the peak regulation cost is specifically as follows:

in the formula,

abandoning light and peak-shaving electric quantity for the called abandoned wind, wherein lambda is the unit cost of abandoning light for the abandoned wind;

using demand side response as peak regulation means M₇And the peak shaving cost is specifically as follows:

in the formula,

scheduling peak shaving capacity participated by response resources of a demand side, wherein mu is the calling cost of response units of the demand side;

the output of the tie line is taken as the peak regulation means M₈The off-area junctor is set as a local-level dispatchable line and a superior-level dispatchable line, the superior-level dispatchable line is set as an un-dispatchable line or a low-priority call, and the situation that after planned output of the junctor is adjusted at a certain moment, the electric quantity deviated from the plan at a proper moment needs to be returned is considered.

2. The method of claim 1, wherein each class of the peak shaver resource M_iThe system peak regulation balance constraint condition needs to be satisfied, and is specifically as follows:

wherein,

the capacity is called for various peak shaving resources,

and predicting output deviation for wind and light renewable energy power generation.

3. The method of claim 2, wherein the method is as set forth in claim 2The mixed integer optimization model comprises three parts of decision variables, constraint conditions and an objective function, wherein the decision variables are various peak-shaving resources M_iPeak shaving capacity provided during a particular time period; the constraint conditions are system peak regulation balance constraint conditions and safety, stability and economy constraint conditions; the objective function is the system peak shaver total cost.

4. The method of claim 3, wherein the objective function comprises an up-peaking objective function and a down-peaking objective function;

the objective function during peak-up regulation is the sum of the coal-electricity peak-regulation fuel consumption cost, the gas power generation fuel consumption cost, the pumping and pumping loss cost, the nuclear power fuel consumption cost and the demand side response cost, and is specifically as follows:

the objective function during the down peak regulation is the sum of the unit coal consumption increasing cost of coal power reduction output, the peak regulation cost during water abandoning of a conventional electric generating set, the pumped storage and pumping loss cost, the wind abandoning and light abandoning cost and the response cost of a demand side, and the cost of other types of down peak regulation resources is 0 and is represented by the following formula:

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