Power grid operation method considering participation of system self-contained power supply in day-ahead market peak

Abstract

The invention discloses a power grid operation method considering participation of a system self-contained power supply in a day-ahead market peak, and belongs to the field of self-contained power supply participation in market scheduling. The power grid operation method considering participation of the system self-contained power supply in the day-ahead market peak comprises the steps that feasibility of grid-connected operation of the self-contained power supply is analyzed, and operation cost models of a typical self-contained power supply are established and comprise a self-contained diesel generator operation cost model, a self-contained energy storage operation cost model and a triple co-generation dispatching cost model; setting a market mechanism of a self-contained power supply peak in a day-ahead market mode, and establishing a self-contained power supply user Bayesian quotation model based on the operation cost model of the typical self-contained power supply; and with the purpose of minimizing the operation cost of the power grid, solving the Bayesian quotation model of the self-contained power supply user by using MATLAB, and obtaining an optimal scheduling strategy of the operation of the power grid.

Description

Technical Field

[0001] The present invention belongs to the field of self-provided power supply participating in market dispatching, and in particular relates to a power grid operation method considering the participation of system self-provided power supply in the day-ahead market peak. Background Art

[0002] In the current context of increasingly tense power supply and demand, the power grid often faces the dilemma of imbalance between supply and demand during peak power consumption. With the increase in population and rapid economic development, power demand continues to rise, resulting in a serious shortage of power supply during peak hours. During the high temperature period in summer, the concentrated use of large power consumers such as air conditioners makes the power grid load almost reach its carrying limit. In order to solve this problem, using the company's own power supply to participate in the peak power grid dispatch has become a feasible way.

[0003] The enterprise's self-provided power supply has flexibility and instant response capabilities. When the load on the power grid increases, it can quickly start generating electricity to meet the urgent demand for electricity. Compared with traditional power grid power generation methods, self-provided power supply can not only reduce the pressure on the power grid, but also improve the stability of the system and reduce the risk of power failure caused by peak load fluctuations. Therefore, the reasonable design of a market mechanism for self-provided power supply to participate in power grid dispatch can not only optimize resource allocation, but also improve the economy and reliability of the power system.

[0004] However, at the current stage, there is a relative lack of peak participation mechanisms for enterprise self-provided power supplies. Although self-provided power supplies can play a good role in dealing with power peaks, there is a lack of effective market mechanisms to regulate and guide their participation in grid dispatching. This has caused many enterprises to be unable to incorporate their self-provided power supplies into grid dispatching in a timely manner during peak periods, missing the best opportunity to match power supply and demand. To this end, a grid operation method that considers the participation of system self-provided power supplies in the day-ahead market peak is proposed. Summary of the invention

[0005] In view of the deficiencies of the prior art, the purpose of the present invention is to provide a power grid operation method that takes into account the participation of the system's self-provided power supply in the day-ahead market peak, thereby solving the problems in the prior art.

[0006] The purpose of the present invention can be achieved by the following technical solutions:

[0007] The grid operation method considering the participation of the system's own power source in the day-ahead market peak includes the following steps:

[0008] Analyze the feasibility of grid-connected operation of self-provided power supply and establish the operation cost model of typical self-provided power supply, including: self-provided diesel generator operation cost model, self-owned energy storage operation cost model and trigeneration dispatch cost model;

[0009] Setting up a market mechanism for the peak of self-provided power supply under the day-ahead market model, and establishing a Bayesian quotation model for self-provided power supply users based on the operation cost model of the typical self-provided power supply;

[0010] The goal is to minimize the grid operation cost, and MATLAB is used to solve the Bayesian quotation model of the self-provided power user to obtain the optimal dispatching strategy for the grid operation.

[0011] Furthermore, the operating cost model of the self-provided diesel generator is:

[0012]

[0013] In the formula, C dg is the unit time cost of self-provided diesel generator, P dg Indicates the self-provided diesel power generation, a dg 、b dg 、c dg and d dg All are operating constants of self-contained power diesel generators.

[0014] Furthermore, the self-owned energy storage operation cost model is:

[0015] C s =α s P s / η d

[0016] Where P s is the energy storage output power, η d Represents the discharge efficiency of electrochemical energy storage, C s is the unit time cost of dispatching energy storage, α s Represents the unit capacity cost.

[0017] Furthermore, the trigeneration scheduling cost model is:

[0018]

[0019] In the formula, C tr is the trigeneration dispatching cost, P tr represents the gas turbine output power, a tr 、b tr and c tr is the trigeneration operation constant.

[0020] Furthermore, the Bayesian quotation model of the self-provided power supply user is:

[0021]

[0022] Q(P it )=mcp

[0023]

[0024] F(P)=kC(P)+b

[0025] Where F(P) represents the bid curve, C(P) represents the cost curve, P represents the declared capacity, k and b are the bid parameters, and Q is the unit bid with respect to the expected dispatch power P. it function, mcp is the compensation price of self-provided power supply; mcp t * represents the clearing electricity price at time t on the day, represents the average of the power grid clearing price at the same time t in the previous ten days, σ 2 (mcp t ) represents the variance of the clearing electricity price at the same time t in the previous ten days, N(μ,σ 2 ) indicates that today's clearing electricity price follows a normal distribution with μ as the central value and σ 2 is the variance; f(mcp) represents the probability distribution function of the power grid clearing price, Q imin represents the lowest unit electricity price declared by user i; E si represents the expected revenue of user i from the peak of self-provided power supply under the market competition mode, C i (P it ) indicates that user i is emitting power P it The unit time cost under i (k,b)≤0 is the restriction condition for user i.

[0026] Furthermore, the process of obtaining the optimal scheduling strategy is:

[0027] The goal of power grid dispatching is to minimize the power grid operation cost. The objective function is as follows:

[0028]

[0029] Where D s represents the grid operation cost under the market competition model, C ht (P ht ) represents the dispatching cost of thermal power units at time t, C zit (P zit ) represents the dispatch cost of user i at time t, which is also the quotation curve of self-provided power supply, and n is the number of self-provided power supply users;

[0030] The power grid dispatching must also meet the power grid power balance limit g(P ht ,P zt )=0, line transmission power limit h(P ht ,P zt )≤0, Self-provided power supply capacity limit m i (Pht ,P zt )≤0; denoted as:

[0031]

[0032] If only the equality constraints of the power grid are considered, the Lagrangian function under the market competition model can be obtained:

[0033]

[0034] Where P Lt represents the total load of the power grid at time t, λ t Represents the T Lagrangian factors introduced; respectively for P ht , P zit , t The partial derivatives are:

[0035]

[0036] From the self-provided power supply mathematical model established above, we know that the cost function of the self-provided power supply for peak capacity is quadratic at most. Therefore, the user's quotation function, that is, the cost function of the self-provided power supply dispatched by the power grid, is also quadratic at most. Therefore, About P zit A linear function with a positive slope is called the consumption increase rate; therefore, the dispatch under the market model can be regarded as the dispatch of equal consumption increase rate; at the same time, if the minimum consumption increase rate of self-provided power supply i is still higher than the grid increase rate during optimization, the self-provided power supply i is dispatched at the lowest capacity; if the maximum consumption increase rate of self-provided power supply i is still lower than the grid increase rate during optimization, the self-provided power supply i is dispatched at the highest capacity.

[0037] Furthermore, the constraints when using MATLAB to solve the Bayesian quotation model for self-provided power users include:

[0038] P dgmin ≤P dg ≤P dgmax

[0039]

[0040] P smin ≤P s ≤P smax

[0041]

[0042] 0.1SOC max ≤SOC t ≤0.9SOC max

[0043]

[0044] P e =η e P tr

[0045] P R =(1-η e ) tr

[0046] P ht =η h P R

[0047]

[0048] P trmin <P tr <P trmax

[0049] P emin <P e <P emax

[0050]

[0051] g(P ht ,P zt )=0

[0052] Where P dgmin and P dgmax They represent the minimum and maximum power output of the self-provided diesel generator respectively; Gd max Indicates the maximum climbing rate; P smin , P smax They represent the minimum and maximum values ​​allowed for energy storage output respectively; SOC0 is the state of charge at the beginning of scheduling, SOC max is the maximum state of charge of the energy storage device, SOC t is the state of charge at time t; C tr is the trigeneration dispatching cost, P tr Indicates the gas turbine output power; P e represents the power generation of the gas turbine, η e Indicates the efficiency of the gas turbine in generating electrical power; P R is the power generated by the waste heat boiler, P ht is the sum of the power generated by the waste heat boiler converted into cooling and heating power, η h is the conversion efficiency; P cool and P heat Represent the power required for cooling load and heating load respectively, η cool and η heat Describe the efficiency of cooling and heating equipment respectively; η grepresents the ratio of gas turbine input to generator, α represents the adjustable range of equivalent heat load; P trmin and P trmax They represent the minimum and maximum power output of the gas turbine, P emin and P emax Respectively represent the minimum and maximum power limits of the generator set output; P i is the injected power of node i, g(P ht ,P zt ) is the power system flow calculation algorithm, and 0 indicates power balance.

[0053] Considering the participation of the system's own power supply in the power grid operation system at the peak of the day-ahead market, including:

[0054] Cost model building module: Analyze the feasibility of grid-connected operation of self-provided power supply and establish the operation cost model of typical self-provided power supply, including: self-provided diesel generator operation cost model, self-owned energy storage operation cost model and trigeneration dispatch cost model;

[0055] The quotation model building module is used to set the market mechanism of the self-provided power supply peak under the day-ahead market model, and to establish a Bayesian quotation model for self-provided power supply users based on the operation cost model of the typical self-provided power supply;

[0056] Model solving module: With the goal of minimizing the grid operation cost, MATLAB is used to solve the Bayesian quotation model of the self-provided power supply user to obtain the optimal dispatching strategy for grid operation.

[0057] A computer storage medium stores a readable program, which, when running, can execute the above-mentioned power grid operation method considering the participation of the system's self-provided power supply in the day-ahead market peak.

[0058] An electronic device, comprising: a processor, a memory, a communication interface and a communication bus, wherein the processor, the memory and the communication interface communicate with each other through the communication bus;

[0059] The memory is used to store at least one executable instruction, and the executable instruction enables the processor to execute operations corresponding to the above-mentioned power grid operation method considering the system's self-provided power supply participating in the day-ahead market peak.

[0060] Beneficial effects of the present invention:

[0061] 1. The present invention establishes an operating cost function model of active distribution network with self-provided power supply, proposes a method for users' self-provided power supply to participate in the peak of the power market through the day-ahead market, establishes a Bayesian quotation model for users of self-provided power supply in the day-ahead market, and establishes an optimal dispatching model for the power market with the participation of self-provided power supply, thereby achieving the goal of safe and stable operation of the system, significantly reducing the operating cost of the power grid, and alleviating the transmission pressure of the distribution network during peak power consumption.

[0062] 2. The present invention sets up a scenario in which self-provided power users participate in the day-ahead market of the power system, establishes a Bayesian quotation model for self-provided power users in the day-ahead market scenario, provides a scientific decision-making basis for self-provided power users to participate in power system dispatching, effectively improves the benefits of self-provided power users, and provides guidance for the comprehensive utilization of self-provided power users' resources. BRIEF DESCRIPTION OF THE DRAWINGS

[0063] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0064] Figure 1 is a power grid topology diagram of Embodiment 2 of the present invention;

[0065] Figure 2 is a typical daily load curve of Example 2 of the present invention;

[0066] Figure 3 is the operating cost-maximum load curve under two scenarios in Example 2 of the present invention;

[0067] Figure 4 It is the power flow distribution diagram of the traditional power grid;

[0068] Figure 5 It is the power flow distribution diagram of the power grid considering the self-provided power supply;

[0069] Figure 6 It is a flow chart of the power grid operation method of the present invention. DETAILED DESCRIPTION

[0070] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0071] Example 1

[0072] like Figure 6 As shown, the grid operation method considering the participation of the system's self-provided power source in the day-ahead market peak includes the following steps:

[0073] S1, analyze the feasibility of grid-connected operation of self-provided power supply and establish the operation cost model of typical self-provided power supply;

[0074] Typical operating cost models of self-provided power sources include: self-provided diesel generator operating cost model, self-owned energy storage operating cost model and trigeneration scheduling cost model.

[0075] 1) The operating cost model of a self-provided diesel generator is:

[0076]

[0077] In the formula, C dg is the unit time cost of self-provided diesel generator, in RMB / hour, P dg Indicates the self-provided diesel power generation, a dg 、b dg 、c dg and d dg All are operating constants of self-contained diesel generators. From the formula, it can be seen that the operating cost of self-contained diesel generators can be composed of two parts, one of which is a quadratic function of the generated power. The other part is proportional to the rate of change of power, which is called the ramp cost.

[0078] The operating restrictions of the self-provided diesel generator are as follows:

[0079] Power upper and lower limits:

[0080] P dgmin ≤P dg ≤P dgmax (2)

[0081] Where P dgmin and P dgmax They respectively represent the minimum and maximum power allowed to be output by the self-contained diesel generator.

[0082] Climbing limit:

[0083]

[0084] Where: Gd max Indicates the maximum climbing rate.

[0085] 2) The operating cost model of self-owned energy storage can be expressed as the following formula:

[0086] C s =α s P s / η d(4)

[0087] Where P s is the energy storage output power, η d Represents the discharge efficiency of electrochemical energy storage, C s is the unit time cost of dispatching energy storage, unit time (yuan / hour), α s Represents the unit capacity cost.

[0088] When scheduling, self-owned energy storage must meet the following restrictions.

[0089] Output power limit:

[0090] P smin ≤P s ≤P smax (5)

[0091] Where: P smin , P smax They represent the minimum and maximum values ​​allowed for the energy storage output respectively.

[0092] State of Charge Limits:

[0093] 0.1SOC max ≤SOC t ≤0.9SOC max (6)

[0094] Where: SOC max is the maximum state of charge of the energy storage device, SOC t is the state of charge at time t. For electrochemical energy storage, the state of charge needs to be between the maximum and minimum allowable battery capacity. According to experience, the best value is 0.1 and 0.9 times the full charge state.

[0095] State of charge calculation:

[0096]

[0097] Where: SOC0 is the state of charge at the beginning of scheduling.

[0098] 3) The participation of trigeneration in self-generated power dispatch means participating in grid dispatch when meeting its own heat load demand, that is, operating in the FTL mode.

[0099] The trigeneration unit satisfies the following basic equation:

[0100]

[0101] P e =η e P tr (9)

[0102] P R =(1-η e ) tr (10)

[0103] P ht =η h P R (11)

[0104]

[0105] In formula (8), C tr is the trigeneration dispatching cost, P tr represents the output power of the gas turbine. The formula shows that the trigeneration scheduling cost is in a quadratic function relationship with the output power of the gas turbine. e represents the power generation of the gas turbine, η e Indicates the efficiency of the gas turbine in generating electrical power. R is the power generated by the waste heat boiler, P in formula (11) ht is the sum of the power generated by the waste heat boiler converted into cooling and heating power, η h is the conversion efficiency. In formula (12), P cool and P heat Represent the power required for cooling load and heating load respectively, η cool and η heat The above formulas show the conversion and quantitative relationship between various powers of trigeneration. The conversion between various powers of trigeneration is roughly as follows: the power output by the gas turbine is converted into electrical power through the power generation equipment, and the remaining power is the boiler preheating power. The waste heat power of the boiler is used to generate the power required for the cooling and heating loads through the cooling and heating equipment.

[0106] The following restrictions on adjustable heat load must be met during trigeneration operation:

[0107]

[0108] Where η g represents the ratio of gas turbine input to generator, and α represents the adjustable range of equivalent heat load.

[0109] In addition, trigeneration should also meet the gas turbine output power limit:

[0110] P trmin <P tr <P trmax (14)

[0111] Where P trmin and P trmax They represent the minimum and maximum power output of the gas turbine respectively.

[0112] Generator output power limit:

[0113] P emin <P e <P emax (15)

[0114] Where P emin and P emax Respectively represent the minimum and maximum power limits of the generator set output.

[0115] After the self-provided power supply is connected to the grid, it will affect the voltage of the power system because of the change in the impedance and reactive power flow of the grid. In general, the voltage of the access point will be raised when the self-provided power supply is connected to the system. If the self-provided power supply user sends power back to the grid at this time, the voltage rise phenomenon at the access point will be more obvious. If the self-provided power supply user chooses not to use the self-provided power supply because the city electricity price is low, and the user's power consumption happens to be large at this time, then the voltage at the access point will drop. In summary, the connection of the self-provided power supply to the grid will increase the voltage fluctuation at the access point. Therefore, in order to ensure the voltage quality of the power grid. It is necessary to use a combination of on-load voltage regulation and capacitor switching to connect the self-provided power supply to improve the ability of the power grid to regulate voltage. In addition, if there is a situation where a large self-provided power supply is connected to the end of the power grid, it is very likely that the fluctuation of the power grid voltage will exceed the regulation ability of the power grid, further increasing the difficulty of power grid voltage balance.

[0116] On the other hand, when a short-circuit fault occurs in the system, the grid-connected self-contained power supply will inject short-circuit current into the fault point through the access point. At the same time, the grid-connected operation of large self-contained power supplies will also increase the short-circuit capacity of the power grid, which may deteriorate the dynamic thermal stability of electrical equipment. If the short-circuit capacity at this time is close to the rated interrupting capacity of the selected circuit breaker, it may bring danger to the system. Therefore, when a large self-contained power supply is connected to the grid, it is necessary to consider appropriately adjusting the rated interrupting capacity.

[0117] The connection of the user's own power supply to the grid will change the power supply structure of the local power supply area, and the conventionally configured relay protection device can no longer meet the system requirements. The changed short-circuit current will also reduce the selectivity and sensitivity of the relay protection equipment and increase the difficulty of setting calculations. If the existing configuration and setting technology of relay protection and automatic devices cannot cope with this change well, it is very likely that the device will not operate correctly, causing damage to the equipment and even leading to the expansion of the accident. Therefore, after the self-provided power supply is connected to the grid, it is necessary to reconsider the neutral point grounding method of the system substation. At the same time, the reclosing, backup power supply automatic investment and main transformer backup protection devices need to be adjusted and modified accordingly. Thereby ensuring the safe and stable operation of the power grid.

[0118] In summary, the use of self-provided power to participate in the peak of the power system requires the power grid to have a good enough voltage regulation capability, and to make corresponding modifications and adjustments to the configuration of the corresponding relay protection and automatic devices to meet the requirements of the self-provided power supply to return power to the power grid under the market model. At the same time, when a power grid failure occurs, small self-provided power users must be quickly cut off to ensure the safe operation of the main grid and restore the main grid power supply as soon as possible.

[0119] S2, setting a market mechanism for the peak of self-provided power supply under the day-ahead market model, and establishing a Bayesian quotation model for self-provided power supply users based on the operation cost model of the typical self-provided power supply;

[0120] The market mechanisms of the day-ahead market model include:

[0121] In the current power system, there are still many obstacles to treating self-provided power supply as a regular power grid power generation enterprise and participating in market competition in the current power market. The most important of these is the problem of power transmission direction. In the research report on rooftop distributed photovoltaics by State Grid Corporation of China, it is mentioned that the current national requirements for rooftop photovoltaics are to consume nearby, balance on site, and not to reversely transmit power to the 220KV and above power grid. Otherwise, it will cause the problem of reverse overload of equipment. Although self-provided power supply has better controllability than rooftop photovoltaics, the hidden danger of reverse power transmission to the main grid still exists. Therefore, for the peak of self-provided power supply under the market mechanism, it is necessary to strictly control the power it generates to be completely consumed in the distribution network.

[0122] In the peak market, it is necessary to have an accurate grasp of the power that needs to be met during the peak period of electricity demand, so the time scale of the self-provided power supply peak must not be very large. Therefore, it is proposed here to open users to participate in the intraday peak market. Considering the intraday peak market of self-provided power supply means that within a few hours during the peak period of electricity demand, users and power generation companies participate in the bidding of the electricity market together, and use the newly generated quotation information of the power grid peak market for unified system scheduling.

[0123] The Bayesian quotation model construction process includes:

[0124] The user-side power supply bidding strategy used in the model is a linear bidding based on power generation cost:

[0125] F(P)=kC(P)+b (16)

[0126] In the formula, F(P) represents the quotation curve, C(P) represents the cost curve, that is, the cost of operating the self-contained power supply established in S1, P represents the declared capacity (power), k and b are quotation parameters. For the quotation curve, if both sides of the equation are divided by the declared power P, it can be regarded as the unit electricity price declared by the user, that is:

[0127]

[0128] When the unit electricity price declared by the user is the same as the unit peak compensation electricity price set by the government, the power at that time can be solved inversely, and the power at that time can be regarded as the capacity declared by the user, that is:

[0129] Q(P it )=mcp (18)

[0130] Where Q is the unit price with respect to the expected dispatch power P it function, mcp is the compensation price of self-provided power supply. In order to balance the power of the power grid in real time, it is necessary to introduce power generation equipment that can balance power into the model, which can be the main power grid.

[0131] Assume that the hourly clearing electricity price of the power grid in recent days can be considered to conform to the normal distribution, and take the hourly clearing electricity price of the past 10 days as a sample. The same treatment is performed on the load curve in recent days.

[0132]

[0133] In the formula, mcp t * represents the clearing electricity price at time t on the day, represents the average of the power grid clearing price at the same time t in the previous ten days, σ 2 (mcp t ) represents the variance of the clearing electricity price at the same time t in the previous ten days, N(μ,σ 2 ) indicates that today's clearing electricity price follows a normal distribution with μ as the central value and σ 2 is the variance.

[0134] Whether the user-side self-provided power supply can be dispatched by the power grid in the competition of the power market depends on whether the lowest unit price of the user's quotation is lower than the clearing price of the power grid. It is known that the clearing price of the power grid at time t on the same day obeys the normal distribution. Then, based on the observable information of user i, the probability that it can be dispatched is

[0135]

[0136] Where f(mcp) represents the probability distribution function of the grid clearing price, Q imin represents the lowest unit electricity price declared by user i; according to the expected profit function v of the Bayesian game model i =p i *u(A i ,θ i ) It can be seen that the user's expected benefits are as follows:

[0137]

[0138] In the formula, E sirepresents the expected revenue of user i from the peak of self-provided power supply under the market competition mode, C i (P it ) indicates that user i is emitting power P it The unit time cost under the condition of user-side self-provided power supply is finally obtained by adjusting the quotation parameters k and b to maximize the user's expected profit under the constraint of user-side self-provided power supply. The constraint condition of user i is m i The optimal quotation model with (k,b)≤0 can be expressed as:

[0139]

[0140] S3, taking the minimization of the grid operation cost as the goal, and using MATLAB to solve the Bayesian quotation model of the self-provided power supply user to obtain the optimal dispatching strategy for the grid operation.

[0141] The process of obtaining the optimal scheduling strategy is:

[0142] The goal of power grid dispatching is to minimize the power grid operation cost. The objective function is as follows:

[0143]

[0144] Where D s represents the grid operation cost under the market competition model, C ht (P ht ) represents the dispatching cost of thermal power units at time t, C zit (P zit ) represents the dispatch cost of user i at time t, which is also the quotation curve of self-provided power supply, and n is the number of self-provided power supply users; the difference here from the demand-side response mode is that the dispatch cost of the peak of self-provided power supply in the demand-side response mode is set by the government and has nothing to do with the user himself; while in the market mode, it is related to the quotation curve of each self-provided power supply;

[0145] At the same time, the power grid dispatching must also meet the power balance limit g(P ht ,P zt )=0, line transmission power limit h(P ht ,P zt )≤0, Self-provided power supply capacity limit m i (P ht ,P zt )≤0; denoted as:

[0146]

[0147] If only the equality constraints of the power grid are considered, the Lagrangian function under the market competition model can be obtained:

[0148]

[0149] Where P Lt represents the total load of the power grid at time t, λ t Represents the T Lagrangian factors introduced. ht , P zit , t The partial derivatives are:

[0150]

[0151] From the self-provided power supply mathematical model established above, we know that the cost function of the self-provided power supply for peak capacity is at most quadratic, so the user's quotation function, that is, the cost function of the grid dispatching the self-provided power supply, is also at most quadratic. About P zit A linear function with a positive slope is called the consumption increment rate. Therefore, the dispatch under the market model can also be regarded as the dispatch of equal consumption increment rate. At the same time, if the minimum value of the consumption increment rate of self-provided power supply i is still higher than the grid increment rate during optimization, the self-provided power supply i is dispatched at the lowest capacity; if the maximum value of the consumption increment rate of self-provided power supply i is still lower than the grid increment rate during optimization, the self-provided power supply i is dispatched at the highest capacity.

[0152] The constraints when solving the Bayesian quotation model for self-provided power users in MATLAB include:

[0153] (1) Diesel generator power constraints:

[0154] P dgmin ≤P dg ≤P dgmax

[0155] Where P dgmin and P dgmax They respectively represent the minimum and maximum power allowed to be output by the self-contained diesel generator.

[0156] (2) Diesel generator climbing limit:

[0157]

[0158] In the formula, Gd max Indicates the maximum climbing rate.

[0159] (3) Output power limit of own energy storage:

[0160] P smin ≤P s ≤P smax

[0161] Where P smin , P smax They represent the minimum and maximum values ​​allowed for the energy storage output respectively.

[0162] (4) Calculation and limitation of state of charge of self-owned energy storage:

[0163]

[0164] 0.1SOC max ≤SOC t ≤0.9SOC max

[0165] Where: SOC0 is the state of charge at the beginning of scheduling, SOC max is the maximum state of charge of the energy storage device, SOC t is the state of charge at time t.

[0166] (5) The trigeneration unit satisfies the basic equation:

[0167]

[0168] P e =η e P tr

[0169] P R =(1-η e ) tr

[0170] P ht =η h P R

[0171]

[0172] In the formula, C tr is the trigeneration dispatching cost, P tr Indicates the gas turbine output power; P e represents the power generation of the gas turbine, η e Indicates the efficiency of the gas turbine in generating electrical power; P R is the power generated by the waste heat boiler, P ht is the sum of the power generated by the waste heat boiler converted into cooling and heating power, η h is the conversion efficiency; P cool and P heat Represent the power required for cooling load and heating load respectively, η cool and η heat State the efficiency of cooling and heating equipment respectively.

[0173] (6) Restrictions on adjustable heat load of trigeneration:

[0174]

[0175] Where ηg represents the ratio of gas turbine input to generator, and α represents the adjustable range of equivalent heat load.

[0176] (7) Output power limits of trigeneration gas turbines and generators:

[0177] P trmin <P tr <P trmax

[0178] P emin <P e <P emax

[0179] Where P trmin and P trmax They represent the minimum and maximum power output of the gas turbine, P emin and P emax Respectively represent the minimum and maximum power limits of the generator set output.

[0180] (8) Power system power balance limit:

[0181]

[0182] g(P ht ,P zt )=0

[0183] Where P i is the injected power of node i, g(P ht ,P zt ) is the power system flow calculation algorithm, and 0 indicates power balance.

[0184] Based on similar inventive concepts, an embodiment of the present invention also provides a computer storage medium storing a readable program, which, when executed, can execute the above-mentioned power grid operation method considering the system's self-provided power supply participating in the day-ahead market peak.

[0185] Based on similar inventive concepts, an embodiment of the present invention provides an electronic device, comprising: a processor, a memory, a communication interface and a communication bus, wherein the processor, the memory and the communication interface communicate with each other through the communication bus;

[0186] The memory is used to store at least one executable instruction, and the executable instruction enables the processor to execute operations corresponding to the above-mentioned power grid operation method considering the system's self-provided power supply participating in the day-ahead market peak.

[0187] Based on similar inventive concepts, an embodiment of the present invention also provides a computer program product, including computer instructions, which instruct a computing device to execute operations corresponding to the above-mentioned power grid operation method considering the system's self-provided power supply participating in the day-ahead market peak.

[0188] Example 2

[0189] In this embodiment, the effectiveness of the power grid operation method proposed in Embodiment 1 is verified through an actual case. Figure 1 The grid topology diagram is an example. Three different types of self-provided power sources are connected to nodes 6, 12 and 17 respectively. They are self-provided diesel generators, trigeneration and self-owned energy storage.

[0190] The parameters used in the model are shown in the following table:

[0191] Table 1: Model parameters

[0192]

[0193] Through Figure 2 The daily load curve in the simulation is scaled proportionally to simulate the operation cost of the traditional power grid under different load curves and the peak power grid of the self-provided power supply under the day-ahead market mode. A typical daily load curve is taken as the power flow distribution diagram.

[0194] When the load is low, the operating cost is lower than the dispatching cost of the other two scenarios, but when the load is high, the dispatching cost will be higher than the dispatching cost under scenario 2, thus losing its advantage. This is because in the market competition mode of scenario 3, the self-provided power supply can transmit power to the distribution network, and there is no restriction that the output power is less than its own load. Therefore, when the total load is low, it can better stimulate the user's self-provided power generation potential, and the operating cost is lower in the market competition scenario. When the demand for the power grid is high, the power market is in short supply. At this time, users will increase their own quotations to obtain higher profits, so the peak effect of the self-provided power supply peak under the market model will deteriorate when the demand for the power grid is high.

[0195] Depend on Figure 3It can be seen that the total operating cost of the power grid increases with the increase of the maximum total load. After adding the self-provided power supply peak of the day-ahead market model, the total operating cost of the power grid is significantly lower than that of the traditional power grid. And with the increase of the maximum total load, the advantage of the self-provided power supply peak in the day-ahead market model gradually weakens. However, the operating cost of the power grid is significantly lower than that of the traditional power grid. However, the advantage in operating cost is very obvious when the maximum load is low. This is because when the total load is low, the self-provided power supply can transmit power to the distribution network in the day-ahead market model, and there is no restriction that the output power is less than its own load. Therefore, when the total load is low, it can better stimulate the user's self-provided power generation potential, and the operating cost is lower in the market competition scenario. When the demand for the power grid is high, the power market is in short supply. At this time, users will increase their own quotations to obtain higher profits, so the peak effect of the self-provided power supply peak in the market model will deteriorate when the demand for the power grid is high.

[0196] Figure 4 The red line indicates the overloaded line. Figure 5 The pink lines in the middle represent the lines that reverse power to the grid. Compared with the traditional grid and the grid considering the self-provided power supply, the latter has improved the power flow distribution during the peak of power consumption, and there is no cross-border phenomenon of the grid line. After the self-provided power supply participates in the peak, the load rate of the line in the distribution network is 59.72%, which is also a significant decrease compared with the 77.56% of the traditional grid. This is because the peak of the self-provided power supply under the day-ahead market model has weakened the load demand of the grid, reduced the terminal power demand, improved the power flow distribution of the grid, and improved the static safety of the power system. At the same time, the peak of the self-provided power supply under the market model under the day-ahead market model has reverse power at the trigeneration. The reversed power here is not transmitted to the grid but is only consumed in the distribution network, which is in line with the designed market mechanism. However, new requirements are put forward for the relay protection devices of the distribution network at the same time.

[0197] Example 3

[0198] In this embodiment, a grid operation system considering the participation of the system's self-provided power supply in the day-ahead market peak is proposed, specifically including:

[0199] Cost model building module: Analyze the feasibility of grid-connected operation of self-provided power supply and establish the operation cost model of typical self-provided power supply, including: self-provided diesel generator operation cost model, self-owned energy storage operation cost model and trigeneration dispatch cost model;

[0200] The quotation model building module is used to set the market mechanism of the self-provided power supply peak under the day-ahead market model, and to establish a Bayesian quotation model for self-provided power supply users based on the operation cost model of the typical self-provided power supply;

[0201] Model solving module: With the goal of minimizing the grid operation cost, MATLAB is used to solve the Bayesian quotation model of the self-provided power supply user to obtain the optimal dispatching strategy for grid operation.

[0202] The method of the present invention may be implemented in hardware, firmware, or as software or computer code that may be stored in a recording medium (such as a CDROM, RAM, floppy disk, hard disk, or magneto-optical disk), or as computer code that is originally stored in a remote recording medium or a non-temporary machine-readable medium downloaded over a network and will be stored in a local recording medium, so that the method described herein may be stored in such software processing on a recording medium using a general-purpose computer, a dedicated processor, or programmable or dedicated hardware (such as an ASIC or FPGA). It is understood that a computer, processor, microprocessor controller, or programmable hardware includes a storage component (e.g., RAM, ROM, flash memory, etc.) that can store or receive software or computer code, and when the software or computer code is accessed and executed by a computer, processor, or hardware, the method described herein is implemented. In addition, when a general-purpose computer accesses the code for implementing the method shown herein, the execution of the code converts the general-purpose computer into a dedicated computer for executing the method shown herein.

[0203] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments, and the above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, and these changes and improvements all fall within the scope of the present invention to be protected.

Claims

1. A power grid operation method considering the participation of the system's own power supply in the day-ahead market peak, characterized in that: The following steps are involved: Analyze the feasibility of grid-connected operation of self-provided power supply and establish the operation cost model of typical self-provided power supply, including: self-provided diesel generator operation cost model, self-owned energy storage operation cost model and trigeneration dispatch cost model; Setting up a market mechanism for the peak of self-provided power supply under the day-ahead market model, and establishing a Bayesian quotation model for self-provided power supply users based on the operation cost model of the typical self-provided power supply; The goal is to minimize the grid operation cost, and MATLAB is used to solve the Bayesian quotation model of the self-provided power user to obtain the optimal dispatching strategy for the grid operation.

2. The method for operating a power grid taking into account the participation of the system's self-provided power supply in the day-ahead market peak according to claim 1, characterized in that: The operating cost model of the self-provided diesel generator is: In the formula, C dg is the unit time cost of self-provided diesel generator, P dg Indicates the self-provided diesel power generation, a dg 、b dg 、c dg and d dg All are operating constants of self-contained power diesel generators.

3. The method for operating a power grid taking into account the participation of the system's self-provided power supply in the day-ahead market peak according to claim 2, characterized in that: The self-owned energy storage operation cost model is: C s =a s P s / or d Where P s is the energy storage output power, η d Represents the discharge efficiency of electrochemical energy storage, C s is the unit time cost of dispatching energy storage, α s Represents the unit capacity cost.

4. The method for operating a power grid taking into account the participation of the system's self-provided power supply in the day-ahead market peak according to claim 3 is characterized in that: The trigeneration scheduling cost model is: In the formula, C tr is the trigeneration dispatching cost, P tr represents the gas turbine output power, a tr 、b tr and c tr is the trigeneration operation constant.

5. The method for operating a power grid taking into account the participation of the system's self-provided power supply in the day-ahead market peak according to claim 4, characterized in that: The Bayesian quotation model of the self-provided power supply user is: Q(P it )=mcp F(P)=kC(P)+b Where F(P) represents the bid curve, C(P) represents the cost curve, P represents the declared capacity, k and b are the bid parameters, and Q is the unit bid with respect to the expected dispatch power P. it function, mcp is the compensation price of self-provided power supply; mcp t * represents the clearing electricity price at time t on the day, represents the average of the power grid clearing price at the same time t in the previous ten days, σ 2 (mcp t ) represents the variance of the clearing electricity price at the same time t in the previous ten days, N(μ,σ 2 ) indicates that today's clearing electricity price follows a normal distribution with μ as the central value and σ 2 is the variance; f(mcp) represents the probability distribution function of the power grid clearing price, Q imin Indicates the lowest unit electricity price declared by user i; E si represents the expected revenue of user i from the peak of self-provided power supply under the market competition mode, C i (P it ) indicates that user i is emitting power P it The unit time cost under i (k,b)≤0 is the restriction condition for user i.

6. The method for operating a power grid taking into account the participation of the system's self-provided power supply in the day-ahead market peak according to claim 5, characterized in that: The process of obtaining the optimal scheduling strategy is as follows: The goal of power grid dispatching is to minimize the power grid operation cost. The objective function is as follows: Where D s represents the grid operation cost under the market competition model, C ht (P ht ) represents the dispatching cost of thermal power units at time t, C zit (P zit ) represents the dispatch cost of user i at time t, which is also the quotation curve of self-provided power supply, and n is the number of self-provided power supply users; The power grid dispatching must also meet the power grid power balance limit g(P ht ,P zt )=0, line transmission power limit h(P ht ,P zt )≤0, Self-provided power supply capacity limit m i (P ht ,P zt )≤0; denoted as: If only the equality constraints of the power grid are considered, the Lagrangian function under the market competition model can be obtained: Where P Lt represents the total load of the power grid at time t, λ t Represents the T Lagrangian factors introduced; respectively for P ht , P zit , t The partial derivatives are: From the self-provided power supply mathematical model established above, we know that the cost function of the self-provided power supply for peak capacity is quadratic at most. Therefore, the user's quotation function, that is, the cost function of the self-provided power supply dispatched by the power grid, is also quadratic at most. Therefore, About P zit A linear function with a positive slope is called the consumption increase rate; therefore, the dispatch under the market model can be regarded as the dispatch of equal consumption increase rate; at the same time, if the minimum consumption increase rate of self-provided power supply i is still higher than the grid increase rate during optimization, the self-provided power supply i is dispatched at the lowest capacity; if the maximum consumption increase rate of self-provided power supply i is still lower than the grid increase rate during optimization, the self-provided power supply i is dispatched at the highest capacity.

7. The method for operating a power grid taking into account the participation of the system's self-provided power supply in the day-ahead market peak according to claim 6, characterized in that: The constraints for solving the Bayesian quotation model for self-provided power users using MATLAB include: P dgmin ≤P dg ≤P dgmax P smin ≤P s ≤P smax 0.1SOC max ≤SOC t ≤0.9SOC max P.S e Hη e P.S tr P.S R (1-η e )P tr P.S ht η h P.S R P trmin <P tr <P trmax P emin <P e <P emax g(P ht ,P zt )=0 Where P dgmin and P dgmax They represent the minimum and maximum power output of the self-provided diesel generator respectively; Gd max Indicates the maximum climbing rate; P smin , P smax They represent the minimum and maximum values ​​allowed for energy storage output respectively; SOC0 is the state of charge at the beginning of scheduling, SOC max is the maximum state of charge of the energy storage device, SOC t is the state of charge at time t; C tr is the trigeneration dispatching cost, P tr Indicates the gas turbine output power; P e represents the power generation of the gas turbine, η e Indicates the efficiency of the gas turbine in generating electrical power; P R is the power generated by the waste heat boiler, P ht is the sum of the power generated by the waste heat boiler converted into cooling and heating power, η h is the conversion efficiency; P cool and P heat Represent the power required for cooling load and heating load respectively, η cool and η heat Describe the efficiency of cooling and heating equipment respectively; η g represents the ratio of gas turbine input to generator, α represents the adjustable range of equivalent heat load; P trmin and P trmax They represent the minimum and maximum power output of the gas turbine, P emin and P emax Respectively represent the minimum and maximum power limits of the generator set output; P i is the injected power of node i, g(P ht ,P zt ) is the power system flow calculation algorithm, and 0 indicates power balance.

8. Considering the participation of the system's own power supply in the power grid operation system at the peak of the day-ahead market, the system is characterized by: include: Cost model building module: Analyze the feasibility of grid-connected operation of self-provided power supply and establish the operation cost model of typical self-provided power supply, including: self-provided diesel generator operation cost model, self-owned energy storage operation cost model and trigeneration dispatch cost model; The quotation model building module is used to set the market mechanism of the self-provided power supply peak under the day-ahead market model, and to establish a Bayesian quotation model for self-provided power supply users based on the operation cost model of the typical self-provided power supply; Model solving module: With the goal of minimizing the grid operation cost, MATLAB is used to solve the Bayesian quotation model of the self-provided power supply user to obtain the optimal dispatching strategy for grid operation.

9. A computer storage medium storing a readable program, characterized in that: When the program is running, it can execute the power grid operation method described in any one of claims 1 to 7 that takes into account the system's self-provided power supply participating in the day-ahead market peak.

10. An electronic device, characterized in that: include: A processor, a memory, a communication interface and a communication bus, wherein the processor, the memory and the communication interface communicate with each other via the communication bus; The memory is used to store at least one executable instruction, and the executable instruction enables the processor to perform operations corresponding to the power grid operation method considering the participation of the system's self-provided power supply in the day-ahead market peak as described in any one of claims 1-7.

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