CN113159980A - Optimal regulation and control method for wind-solar absorption-improving thermoelectric combined system - Google Patents
Optimal regulation and control method for wind-solar absorption-improving thermoelectric combined system Download PDFInfo
- Publication number
- CN113159980A CN113159980A CN202011519542.1A CN202011519542A CN113159980A CN 113159980 A CN113159980 A CN 113159980A CN 202011519542 A CN202011519542 A CN 202011519542A CN 113159980 A CN113159980 A CN 113159980A
- Authority
- CN
- China
- Prior art keywords
- stage
- model
- dirichlet
- unit
- constructing
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 238000000034 method Methods 0.000 title claims abstract description 53
- 238000009826 distribution Methods 0.000 claims abstract description 34
- 238000005457 optimization Methods 0.000 claims abstract description 28
- 238000010248 power generation Methods 0.000 claims abstract description 25
- 230000031700 light absorption Effects 0.000 claims abstract description 7
- 238000010276 construction Methods 0.000 claims abstract description 5
- 230000008569 process Effects 0.000 claims description 10
- 238000004422 calculation algorithm Methods 0.000 claims description 7
- 238000005516 engineering process Methods 0.000 claims description 7
- 239000002356 single layer Substances 0.000 claims description 7
- 238000006243 chemical reaction Methods 0.000 claims description 6
- 238000005485 electric heating Methods 0.000 claims description 6
- 238000012545 processing Methods 0.000 claims description 6
- 239000010410 layer Substances 0.000 claims description 5
- 239000000126 substance Substances 0.000 claims description 4
- IAZDPXIOMUYVGZ-UHFFFAOYSA-N Dimethylsulphoxide Chemical compound CS(C)=O IAZDPXIOMUYVGZ-UHFFFAOYSA-N 0.000 claims description 3
- 230000005540 biological transmission Effects 0.000 claims description 3
- 230000008878 coupling Effects 0.000 claims description 3
- 238000010168 coupling process Methods 0.000 claims description 3
- 238000005859 coupling reaction Methods 0.000 claims description 3
- 230000009977 dual effect Effects 0.000 claims description 3
- 238000005286 illumination Methods 0.000 claims description 3
- 238000007373 indentation Methods 0.000 claims description 3
- 125000004122 cyclic group Chemical group 0.000 claims 1
- 230000007246 mechanism Effects 0.000 abstract description 3
- 230000003044 adaptive effect Effects 0.000 abstract description 2
- 230000005622 photoelectricity Effects 0.000 description 4
- 230000001186 cumulative effect Effects 0.000 description 3
- 230000005611 electricity Effects 0.000 description 3
- 230000008901 benefit Effects 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 238000010438 heat treatment Methods 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 238000003462 Bender reaction Methods 0.000 description 1
- 238000013459 approach Methods 0.000 description 1
- 238000004364 calculation method Methods 0.000 description 1
- 230000000295 complement effect Effects 0.000 description 1
- 230000001276 controlling effect Effects 0.000 description 1
- 238000000354 decomposition reaction Methods 0.000 description 1
- 238000009795 derivation Methods 0.000 description 1
- 238000013461 design Methods 0.000 description 1
- 238000005315 distribution function Methods 0.000 description 1
- 230000002708 enhancing effect Effects 0.000 description 1
- 239000011159 matrix material Substances 0.000 description 1
- 230000001105 regulatory effect Effects 0.000 description 1
- 238000007619 statistical method Methods 0.000 description 1
Images
Classifications
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06Q—INFORMATION AND COMMUNICATION TECHNOLOGY [ICT] SPECIALLY ADAPTED FOR ADMINISTRATIVE, COMMERCIAL, FINANCIAL, MANAGERIAL OR SUPERVISORY PURPOSES; SYSTEMS OR METHODS SPECIALLY ADAPTED FOR ADMINISTRATIVE, COMMERCIAL, FINANCIAL, MANAGERIAL OR SUPERVISORY PURPOSES, NOT OTHERWISE PROVIDED FOR
- G06Q50/00—Systems or methods specially adapted for specific business sectors, e.g. utilities or tourism
- G06Q50/06—Electricity, gas or water supply
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F30/00—Computer-aided design [CAD]
- G06F30/20—Design optimisation, verification or simulation
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J3/00—Circuit arrangements for ac mains or ac distribution networks
- H02J3/38—Arrangements for parallely feeding a single network by two or more generators, converters or transformers
- H02J3/381—Dispersed generators
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F2111/00—Details relating to CAD techniques
- G06F2111/04—Constraint-based CAD
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F2113/00—Details relating to the application field
- G06F2113/06—Wind turbines or wind farms
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J2300/00—Systems for supplying or distributing electric power characterised by decentralized, dispersed, or local generation
- H02J2300/20—The dispersed energy generation being of renewable origin
- H02J2300/22—The renewable source being solar energy
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J2300/00—Systems for supplying or distributing electric power characterised by decentralized, dispersed, or local generation
- H02J2300/20—The dispersed energy generation being of renewable origin
- H02J2300/28—The renewable source being wind energy
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E10/00—Energy generation through renewable energy sources
- Y02E10/70—Wind energy
- Y02E10/76—Power conversion electric or electronic aspects
Abstract
The optimal regulation and control method for the combined heat and power system for improving wind and light absorption comprises the steps of establishing a combined heat and power model comprising a wind power generation system, a photovoltaic power generation system and a cogeneration system, establishing a Dirichlet fuzzy set, establishing a two-stage combined heat and power system distributed robust model, and solving the two-stage combined heat and power system distributed robust model. The fuzzy set constructed by the invention contains potential actual probability distribution, and a narrower fuzzy set can be constructed by more observation data so as to reduce model conservatism. The construction of the fuzzy set can be converted into a deterministic problem, so that the fuzzy set is connected with a traditional adaptive robust optimization model, and the constructed distributed robust model has inheritance. The model constructed by the invention is based on a thermoelectric system scheduling architecture, follows a self-adaptive mechanism between cooperative regulation and robust optimization, and the obtained result can be directly used for solving the system optimization regulation problem of the current thermoelectric system.
Description
Technical Field
The invention belongs to the technical field of optimization of a combined heat and power system, and particularly relates to a combined heat and power system optimization regulation and control method for improving wind and light absorption.
Background
In the winter heating period in northern China, a large number of cogeneration units work in a 'fixed power by heat' operation mode, so that the peak regulation capacity of the system is insufficient, and the situation of wind and light abandonment is severe. The wind power heat supply of abandoned wind can be effectively reduced, and the economic benefit problem and the scheduling platform are not perfect, so that the large-scale popularization and application are difficult. In addition, the increase of the grid-connected amount of the distributed energy greatly influences the safe and stable operation of the power system. Thus, the introduction of the cogeneration system greatly ameliorates the above-described problems. However, in optimizing the scheduling process, the cogeneration system faces many uncertainties, such as the production of renewable energy (wind or solar), market prices, load demands, etc. Obviously, the traditional deterministic optimization method cannot adapt to the combined heat and power optimization scheduling problem considering various uncertainties. Therefore, a reasonable scheduling method is adopted to quantify or weaken the influence of uncertainty on the scheduling strategy, and great attention is paid to people.
For uncertainty in the operation of cogeneration systems, the most basic optimization methods currently include Interval Optimization (IO), Stochastic Programming (SP), and Robust Optimization (RO). In the related technology I, a thermoelectric combined system economic dispatching model with interval uncertainty is established, and then the interval-based economic dispatching model is converted into a deterministic economic dispatching model for solving through probability degree definition. The method is convenient for solving the actual engineering problem, but the decision in the interval number form is not easy to be directly applied. The SP method is another popular method. The method presupposes probability density functions of uncertain parameters, e.g. wind speed models usually follow a weibull distribution. In order to minimize the day-ahead cost and balance the market of the cogeneration system, considering the uncertainty of the wind power and load demand, the second related art proposes a random two-tier optimization problem of renewable energy utilization. The SP method is based on known probability density, but is not suitable for practical situations where it is difficult to find the probability density function of uncertainty. In addition, the scenes generated by the SP method also cause an increase in the amount of calculation. And in the third related technology, under the condition of considering uncertainty of market price, a community energy hub optimal load scheduling model for reducing the total cost is provided. The method takes the boundary of uncertain parameters as a representative, and is difficult to select a proper robust set, so that the result becomes conservative.
In recent years, Distributed Robust Optimization (DRO) has been widely applied to solving uncertainty optimization problems. And combining the advantages of the SP and the RO, wherein the DRO implements a scheduling strategy under the worst uncertain probability distribution in the fuzzy set, and the construction of the fuzzy set is a key factor strategy for influencing scheduling. And a two-stage distribution robust model is established in the fourth related technology, and the optimal quotation strategy of a certain comprehensive wind power plant is deduced. The wind power generation output is used as an uncertain parameter and is characterized by a fuzzy set defining a distribution family. The optimal decision of the bidding strategy is robust to the expectation of the worst case distribution.
Disclosure of Invention
The invention aims to at least solve one of the technical problems in the prior art and provides a combined heat and power system optimization regulation and control method for improving wind and light absorption.
The invention provides a thermoelectric combined system optimization regulation and control method for improving wind and light absorption, which comprises the following steps:
establishing a combined heat and power model comprising a wind power generation system, a photovoltaic power generation system and a combined heat and power generation system;
constructing a Dirichlet fuzzy set;
constructing a two-stage electric heating combined system distributed robust model;
and solving the distributed robust model of the two-stage electric heating combined system.
In some optional embodiments, the building a cogeneration model including a wind power generation system, a photovoltaic power generation system, and a cogeneration system includes:
processing uncertainty of wind speed by using Weibull distribution to construct a wind power generation model;
processing the uncertainty of illumination by utilizing beta distribution to construct a photovoltaic power generation model;
and establishing an electric heat output model of the cogeneration technology according to the electric heat coupling characteristic of the cogeneration technology.
In some optional embodiments, said constructing the dirichlet fuzzy set comprises:
constructing a Dirichlet hybrid model according to the non-supervised classified Dirichlet process;
and constructing the Dirichlet fuzzy set by combining a variation inference principle.
In some optional embodiments, the constructing a dirichlet hybrid model according to the unsupervised classified dirichlet process includes:
the prior dirichlet probability density function is:
in the formula, Γ (—) is represented by a Gamma function, and r ═ r (r)1,r2,...,rn),riAs a prior parameter, satisfies r is more than or equal to 0iLess than or equal to 1 andrepresenting the parameter thetaiMean value, beta, under Dirichlet prior distributioni=sri,βiRepresentation priorWeighting or implicit observations of the information, s being set at [1,2 ]]Internal;
after obtaining the sample observation value M, the prior dirichlet probability density function is updated by the bayesian process to obtain a posterior distribution:
wherein M is the total number of sample observations, MiIndicating the situation xi in M observationsiThe number of occurrences;
after obtaining the data observations, the parameter θ is giveniMean value r of prior probabilitiesiThe situation ξ is estimated from the expected value of the posterior distribution shown in the following expression (3)iThe posterior probability of occurrence, i.e.:
the Dirichlet fuzzy set is constructed by combining a variation inference principle, and the construction method comprises the following steps:
obtaining the minimum value and the maximum value of the posterior expected value of the parameter by adopting a parameter estimation method:
in some optional embodiments, the constructing the two-stage electric-thermal combined system distributed robust model comprises:
constructing a two-stage objective function, wherein the first stage is to minimize the cost of a pre-dispatching stage, and the second stage is to minimize the cost of a readjusting stage;
and constructing the constraint condition of the two-stage objective function.
In some optional embodiments, the objective function of the first stage is:
wherein variables are aggregated Andis the supply price of the electric energy and the heat energy of the CHP unit c,andis the up/down reserve price of the CHP and CTP units,is the electric energy quotation of the CTP unit g, Sc/BcAnd Sg/BgThe starting and stopping costs of the CHP unit c and the CTP unit g are respectively,andis the output power of the electric energy and the heat energy of the CHP unit c,is the electric energy output power of the CTP unit g,andis the upper/lower spare consumption of the CHP/CTP unit, vc,t/zc,t/vg,t/zg,tIs a binary variable when v isc,t1 denotes time CHPStarting the unit h, then the starting cost ShIs calculated into the total cost, otherwise, the shutdown cost BhIs calculated into the total cost, SgAnd BgIs the start-stop cost of CTP set, phiCHPAnd phiCTPIs a CHP unit and a CTP unit set;
the constraints of the objective function of the first stage are:
wherein, BnmIs the admittance between transmission lines nm, deltan,tAnd deltam,tRespectively the phase angle between the busbars n and m,andis a WPP unit w and a PV unitpThe output power of the power converter (c),is the demanded rated power of load l;
andis the heat-electricity conversion proportion of the cogeneration unit,andrepresents an up/down reserve capacity;
In some optional embodiments, the objective function of the second stage is:
wherein, the variable setFor any time, it is the uncertain parameter, variable set of readjustment stageIs the decision variable of the second stage and,andthe upward/downward adjustment amounts of the CHP unit and the CTP unit respectively,the supply and demand after the rotating reserve is provided are unbalanced;
the constraints of the objective function of the second stage are:
wherein the constraint (20) is a power balance at real time operation,andand the phase angle between the buses n and m in the second adjustment stage, and the constraint (21) to (24) are constrained by the scheduling result of the first stage, so that each unit is limited and adjusted in real time.
In some optional embodiments, the solving the two-stage electric-thermal combined system distributed robust model comprises:
converting the second-stage double-layer problem into a single-layer problem by using a KKT condition;
and circularly solving the two-stage problem by using a C & CG algorithm.
In some optional embodiments, the two-stage electric-thermal combined system distributed robust model is:
in some optional embodiments, the solving the two-stage problem circularly using the C & CG algorithm includes:
decomposing the two-stage problem into a Main Problem (MP) and a Sub Problem (SP), and then carrying out iterative solution;
in each iteration, the optimal solution of the SP is transferred into the MP containing new variables and corresponding constraints;
the MP is described by the following equation (26), the worst uncertainty pi found from the SP of the previous iteration*The total cost is minimized in the case:
wherein the content of the first and second substances,
the conversion of the second stage double layer problem to a single layer problem using the KKT condition includes:
converting the SP to an equivalent single layer problem:
where λ is the dual parameter in equation (25) and j is the indentation of the corresponding constraint.
The fuzzy set constructed by the invention contains potential actual probability distribution, and a narrower fuzzy set can be constructed by more observation data so as to reduce model conservatism. The construction of the fuzzy set can be converted into a deterministic problem, so that the fuzzy set is connected with a traditional adaptive robust optimization model, and the constructed distributed robust model has inheritance. Compared with the traditional method for giving the uncertain set boundary, the model method provided by the invention does not need to know the specific probability distribution of wind power and photoelectricity, can construct the wind power photovoltaic output interval by using a small amount of information under the condition that the historical data of the wind power and the photoelectricity are limited, can realize the conservative control of the robust optimization model by adjusting the uncertainty parameter, and improves the applicability of the model and the method. The model constructed by the invention is based on a thermoelectric system scheduling architecture, follows a self-adaptive mechanism between cooperative regulation and robust optimization, and the obtained result can be directly used for solving the system optimization regulation problem of the current thermoelectric system.
Drawings
FIG. 1 is a flow chart of a method for optimizing and controlling a combined heat and power system for enhancing wind and light absorption according to an embodiment of the invention;
FIG. 2 is a schematic diagram illustrating the CDF confidence as the number of samples increases, in accordance with an embodiment of the present invention;
FIG. 3 is a diagram illustrating conversion of a fuzzy set into an uncertainty set according to another embodiment of the present invention.
Detailed Description
In order to make the technical solutions of the present invention better understood, the present invention will be described in further detail with reference to the accompanying drawings and specific embodiments.
As shown in fig. 1, a method S100 for optimally regulating a cogeneration system to improve wind and light absorption includes steps S110, S120, S130, and S140.
And S110, establishing a combined heat and power model comprising a wind power generation system, a photovoltaic power generation system and a cogeneration system. Step S110 specifically includes the following steps:
and processing uncertainty of wind speed by using Weibull (Weibull) distribution to construct a wind power generation model.
And (3) processing the uncertainty of illumination by utilizing Beta distribution to construct a photovoltaic power generation model.
And establishing a heat and power (CHP) electric heat output model according to the electric heat coupling characteristic of the CHP.
And S120, constructing a Dirichlet fuzzy set.
First, a dirichlet hybrid model is constructed according to the unsupervised classified dirichlet process.
Suppose there are N possible occurrences of an event, each with ξiIndicating that the sample space for this event is Ω ═ ξ1,ξ2,...,ξn}; each instance of the event has a completely uniform probability distribution, with the probability of each instance occurring being equal to (θ)1,θ2,...,θn) And (4) showing. With the aid of the bayesian statistical principle, the prior distribution of dirichlet in the deterministic dirichlet model of the random variable can be expressed by the shown dirichlet distribution, and the prior dirichlet probability density function is expressed by the following formula (1):
in the formula, Γ (×) is represented as a Gamma function; r ═ r (r)1,r2,...,rn),riAs a prior parameter, satisfies r is more than or equal to 0iLess than or equal to 1 andrepresenting the parameter thetaiAverage under Dirichlet prior distribution, for convenience of expression, specifies betai=sri,βiWeights or implicit observations representing a priori information, s being usually set at 1,2]And (4) the following steps.
After obtaining the sample observation value M, the prior dirichlet probability density function is updated by the bayesian process, and a posterior distribution can be obtained, as shown in the following formula (2):
wherein M is the total number of sample observations, MiIndicating the situation xi in M observationsiThe number of occurrences.
After obtaining the data observations, the parameter θ is giveniMean value r of prior probabilitiesiExpected according to the posterior distribution shown in the following formula (3)The value estimates the situation xiiThe posterior probability of occurrence, i.e.:
as can be seen from the derivation of the deterministic Dirichlet model shown in equation (3), it is necessary to perform statistical analysis on each riIs set, in other words, the probability of each occurrence of a random event is determined by the prior weight βiAnd (6) determining. However, the existing data information is limited, the samples are insufficient, and the r cannot be correctediGives reasonable guidance when r isiWhen the setting is not reasonable, the accuracy of probability estimation is affected.
In order to avoid the disadvantages of the deterministic dirichlet method, a parameter estimation method is adopted to obtain the minimum value and the maximum value of the parameter posterior expected value, as shown in the following formula (4):
the Cumulative Distribution Function (CDF) confidence band contains the true probability Distribution information of the random variable, but does not necessarily contain the estimated range [ ξ ] of the true value of the random variablel,ξu]. Notably, the purpose of fuzzy set design is to encode the information of the CDF confidence interval without assuming any a priori knowledge about the distribution type. As shown in fig. 2, a line (i) represents a lower boundary of a confidence interval of 200 samples, a line (ii) represents a lower boundary of a confidence interval of 2000 samples, a line (iii) represents a lower boundary of a confidence interval of 20000 samples, a line (iv) represents a real cumulative probability distribution, a line (v) represents an upper boundary of a confidence interval of 20000 samples, a line (c) represents a lower boundary of a confidence interval of 2000 samples, and a line (c) represents a lower boundary of a confidence interval of 200 samples. The fuzzy set becomes narrower and narrower by collecting more and more historical data according to the convergence of the confidence interval shown in fig. 2. Taking wind power as an example, when the random variable is the wind power output, the wind power output can be set according to the CDF confidence bandProbability point of (1-gamma)/2, (1+ gamma)/2]Finding out the corresponding real wind power output intervalFIG. 3 shows the process of converting a fuzzy set into an uncertain set, wherein the linesRepresenting the lower boundary of the confidence interval, lineLines representing the true cumulative probability distributionRepresenting the upper boundary of the confidence interval. As can be seen from fig. 3, the fuzzy set constructed according to the non-exact dirichlet allocation model method is mapped to the boundary of the wind power uncertain set. According to the method, the wind power uncertain interval can be effectively constructed under the conditions that wind power historical data are limited and wind power does not need to be assumed to obey any specific distribution, so that the requirements on wind power historical statistical data are greatly reduced, the universality of the model and the method is improved, and the distributed robust optimization problem is effectively constructed.
Fuzzy sets, in contrast to uncertain sets in conventional robust optimizationIs a set of probability distributions (metrics). In the traditional robust optimization, the worst wind power output in an uncertain set is optimized, and the worst probability distribution in a fuzzy set is optimized in the distributed robust optimization.
Compared with the traditional method for giving the uncertain set boundary, the non-precise Dirichlet model method of the embodiment does not need to know the specific probability distribution of wind power and photoelectricity, and can construct the wind power photovoltaic output interval by using a small amount of information under the condition that the historical data of the wind power and the photoelectricity are limited.
S130, constructing a two-stage electric heating combined system distributed robust model. Step S130 specifically includes:
and constructing a two-stage objective function, wherein the first stage is to minimize the cost of the pre-dispatching stage, and the second stage is to minimize the cost of the readjusting stage.
And constructing the constraint condition of the two-stage objective function.
In the first stage, the day-ahead pre-scheduling cost mainly comprises the electricity and heat production cost of a Combined Heat and Power (CHP) unit, the electricity generation cost of a thermal power (CTP) unit, the spare capacity cost and the start/stop cost.
The objective function of the first stage is:
wherein variables are aggregated Andis the supply price of the electric energy and the heat energy of the CHP unit c,andis the up/down reserve price of the CHP and CTP units,is the electric energy quotation of the CTP unit g, Sc/BcAnd Sg/BgThe starting and stopping costs of the CHP unit c and the CTP unit g are respectively,andis the output power of the electric energy and the heat energy of the CHP unit c,is the electric energy output power of the CTP unit g,andis the upper/lower spare consumption of the CHP/CTP unit, vc,t/zc,t/vg,t/zg,tIs a binary variable, e.g. when vc,tWhen the time t indicates that the CHP unit h starts, the starting cost S is 1hShould be calculated into the total cost, otherwise, the shutdown cost BhShould be calculated into the total cost, SgAnd BgIs the start-stop cost of CTP set, phiCHPAnd phiCTPIs a CHP and CTP unit set.
At this stage, since the power generation characteristics of different units in the cogeneration system are different, it is necessary to convert the outputs of the respective units into Direct Current (DC) in a unified manner in order to achieve power convergence in the scheduling stage. Therefore, a DC power flow model is adopted, as shown in the following formula (6), wherein BnmIs the admittance between transmission lines nm, deltan,tAnd deltam,tRespectively the phase angle between the busbars n and m.Andis a wind power generation (WPP) set w and a photovoltaic power generation (PV) setpThe output power of (1).Is the demanded rated power of the load l. Constraints (7) and (9) are the power generation capacity limits of the CHP unit and the CTP unit. It is worth mentioning that the CHP unit used by the system operates in the traditional "follow-up thermal load" mode, which is the feasible operating region of the scheduling level in timeThe domain is limited by (8).Andis the thermoelectric conversion proportion of the cogeneration unit.Andindicating an up/down reserve capacity. Constraints (10), (11), (12), (13) and (14) are ramp rate constraints for CHP and CTP.Andis a ramp rate up/down ramp rate limit. u. ofc,tAnd ug,tIs a binary variable describing the on/off state. Minimum continuous run/shut down time to ensure economy and safety of the systemAndare set at the constraints (15), (16), (17) and (18).
That is, the constraint of the objective function of the first stage is:
and in the second stage, modeling is carried out on uncertainty in wind power output, solar photovoltaic output and load requirements by using the fuzzy set generated in the previous step, so as to obtain a distributed robust optimization model. Notably, cogeneration systems can represent a price recipient. Therefore, the present embodiment ignores uncertainty of market price. In this sense, the present embodiment minimizes the real-time readjustment cost of the cogeneration system, which mainly includes the adjustment cost of the CHP unit and the CTP unit and the cost of the grid imbalance.
The objective function for the second stage is:
wherein, the variable setAt any time, are uncertain parameters of the readjustment phase, which follow the fuzzy set established in the previous step. It should be noted that the heat demand is provided by district heating, and therefore, its uncertainty is much less than at iiVPPThe uncertainty parameter of (1). Therefore, we assume that the thermal load demand of the second stage is equal to the predicted value of the first stage. Variable setIs the decision variable for the second stage.Andthe up/down adjustment amounts of the CHP unit and the CTP unit are respectively.Meaning the imbalance in supply and demand after the provision of rotating reserve. Since the cogeneration system is a grid connection system, unbalanced electric energy can pass through the priceAndis the electricity price of the CHP unit and the CTP unit in the second adjusting stage.
The second stage problem is formulated based on the worst case and day-ahead planning of the first stage uncertain fuzzy sets. The constraint (20) is a power balance at real-time runtime, wherein,andis the phase angle between the busbars n and m of the second adjustment phase. And the constraints (21) to (24) are constrained by the scheduling result of the first stage, and each unit is limited and adjusted in real time.
That is, the constraint conditions of the objective function in the second stage are:
according to the embodiment, the conservative property of the robust optimization model can be controlled by adjusting the uncertainty parameter, and the applicability of the model and the method is improved.
And S140, solving the distributed robust model of the two-stage electric heating combined system. Step S140 specifically includes:
the second stage double layer problem was converted to a single layer problem using karuo-Kuhn-Tucker (KKT) conditions.
And circularly solving the two-stage problem by using a column constraint generation (C & CG) algorithm.
The two-stage model constructed in the previous step is represented in a compact matrix form and a concise notation, that is, the two-stage electric-heat combined system distributed robust model is represented by the following formula (25):
the proposed two-stage distributed robust optimization is usually solved using a cut plane based approach. Compared with Benders decomposition technique in the related art, C&The CG algorithm has better convergence. C&The core of the CG algorithm is to decompose the two-stage problem into a Main Problem (MP) and a sub-problem (SP), and then solve iteratively. In each iteration, the optimal solution for the SP is transferred to the MP containing new variables and corresponding constraints. MP is described by the following equation (26), the worst uncertainty pi found from the SP of the previous iteration*The overall cost is minimized.
Wherein the content of the first and second substances,
since the max-min problem is not easily solved directly by commercial solvers, it is possible to convert SPs to an equivalent single-stage problem. The KKT condition may be used here because the internal minimum problem for SP is linear.
Where λ is the dual parameter in equation (25) and j is the indentation of the corresponding constraint.
Notably, the nonlinear complementary constraint can be linearized with a large M method.
The model constructed in the embodiment is based on a thermoelectric system scheduling architecture, and follows a self-adaptive mechanism between cooperative regulation and robust optimization, and the obtained result can be directly used for solving the problem of optimal regulation and control of the current thermoelectric system.
It will be understood that the above embodiments are merely exemplary embodiments taken to illustrate the principles of the present invention, which is not limited thereto. It will be apparent to those skilled in the art that various modifications and improvements can be made without departing from the spirit and substance of the invention, and these modifications and improvements are also considered to be within the scope of the invention.
Claims (10)
1. A thermoelectric combined system optimization regulation and control method for improving wind and light absorption is characterized by comprising the following steps:
establishing a combined heat and power model comprising a wind power generation system, a photovoltaic power generation system and a combined heat and power generation system;
constructing a Dirichlet fuzzy set;
constructing a two-stage electric heating combined system distributed robust model;
and solving the distributed robust model of the two-stage electric heating combined system.
2. The method of claim 1, wherein establishing a cogeneration model comprising a wind power generation system, a photovoltaic power generation system, and a cogeneration system comprises:
processing uncertainty of wind speed by using Weibull distribution to construct a wind power generation model;
processing the uncertainty of illumination by utilizing beta distribution to construct a photovoltaic power generation model;
and establishing an electric heat output model of the cogeneration technology according to the electric heat coupling characteristic of the cogeneration technology.
3. The method of claim 1, wherein said constructing a Dirichlet fuzzy set comprises:
constructing a Dirichlet hybrid model according to the non-supervised classified Dirichlet process;
and constructing the Dirichlet fuzzy set by combining a variation inference principle.
4. The method of claim 3,
the constructing of the dirichlet hybrid model according to the unsupervised classified dirichlet process includes:
the prior dirichlet probability density function is:
in the formula, Γ (—) is represented by a Gamma function, and r ═ r (r)1,r2,...,rn),riAs a prior parameter, satisfies r is more than or equal to 0iLess than or equal to 1 andrepresenting the parameter thetaiMean value, beta, under Dirichlet prior distributioni=sri,βiWeights or implicit observations representing a priori information, s being set at [1,2 ]]Internal;
after obtaining the sample observation value M, the prior dirichlet probability density function is updated by the bayesian process to obtain a posterior distribution:
wherein M is the total number of sample observations, MiIndicating the situation xi in M observationsiThe number of occurrences;
after obtaining the data observations, the parameter θ is giveniMean value r of prior probabilitiesiThe situation ξ is estimated from the expected value of the posterior distribution shown in the following expression (3)iThe posterior probability of occurrence, i.e.:
the Dirichlet fuzzy set is constructed by combining a variation inference principle, and the construction method comprises the following steps:
obtaining the minimum value and the maximum value of the posterior expected value of the parameter by adopting a parameter estimation method:
5. the method of claim 1, wherein constructing the two-stage electric-thermal combined system distributed robust model comprises:
constructing a two-stage objective function, wherein the first stage is to minimize the cost of a pre-dispatching stage, and the second stage is to minimize the cost of a readjusting stage;
and constructing the constraint condition of the two-stage objective function.
6. The method of claim 5, wherein the objective function of the first stage is:
wherein variables are aggregated Andis the supply price of the electric energy and the heat energy of the CHP unit c,andis the up/down reserve price of the CHP and CTP units,is the electric energy quotation of the CTP unit g, Sc/BcAnd Sg/BgThe starting and stopping costs of the CHP unit c and the CTP unit g are respectively,andis the output power of the electric energy and the heat energy of the CHP unit c,is the electric energy output power of the CTP unit g,andis the upper/lower spare consumption of the CHP/CTP unit, vc,t/zc,t/vg,t/zg,tIs a binary variable when v isc,tWhen the time t indicates that the CHP unit h starts, the starting cost S is 1hIs calculated into the total cost, otherwise, the shutdown cost BhIs calculated into the total cost, SgAnd BgIs the start-stop cost of CTP set, phiCHPAnd phiCTPIs a CHP unit and a CTP unit set;
the constraints of the objective function of the first stage are:
wherein, BnmIs the admittance between transmission lines nm, deltan,tAnd deltam,tRespectively the phase angle between the busbars n and m,andis the output power of the WPP unit w and the PV unit p,is the demanded rated power of load l;
andis the heat-electricity conversion proportion of the cogeneration unit,andrepresents an up/down reserve capacity;
7. The method of claim 6, wherein the objective function of the second stage is:
wherein, the variable setFor any time, it is the uncertain parameter, variable set of readjustment stageIs the decision variable of the second stage and,andthe upward/downward adjustment amounts of the CHP unit and the CTP unit respectively,the supply and demand after the rotating reserve is provided are unbalanced;
the constraints of the objective function of the second stage are:
8. The method of claim 7, wherein the solving the two-stage combined heat and power system distributed robust model comprises:
converting the second-stage double-layer problem into a single-layer problem by using a KKT condition;
and circularly solving the two-stage problem by using a C & CG algorithm.
10. the method of claim 9,
the cyclic solution of the two-stage problem by using the C & CG algorithm comprises the following steps:
decomposing the two-stage problem into a main problem MP and a sub problem SP, and then carrying out iterative solution;
in each iteration, the optimal solution of the SP is transferred into the MP containing new variables and corresponding constraints;
the MP is described by the following equation (26), the worst uncertainty pi found from the SP of the previous iteration*The total cost is minimized in the case:
wherein the content of the first and second substances,
the conversion of the second stage double layer problem to a single layer problem using the KKT condition includes:
converting the SP to an equivalent single layer problem:
where λ is the dual parameter in equation (25) and j is the indentation of the corresponding constraint.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CN202011519542.1A CN113159980A (en) | 2020-12-21 | 2020-12-21 | Optimal regulation and control method for wind-solar absorption-improving thermoelectric combined system |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CN202011519542.1A CN113159980A (en) | 2020-12-21 | 2020-12-21 | Optimal regulation and control method for wind-solar absorption-improving thermoelectric combined system |
Publications (1)
Publication Number | Publication Date |
---|---|
CN113159980A true CN113159980A (en) | 2021-07-23 |
Family
ID=76882642
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
CN202011519542.1A Pending CN113159980A (en) | 2020-12-21 | 2020-12-21 | Optimal regulation and control method for wind-solar absorption-improving thermoelectric combined system |
Country Status (1)
Country | Link |
---|---|
CN (1) | CN113159980A (en) |
-
2020
- 2020-12-21 CN CN202011519542.1A patent/CN113159980A/en active Pending
Similar Documents
Publication | Publication Date | Title |
---|---|---|
WO2022100091A1 (en) | Centralized control method for scheduling of generalized source storage system | |
CN108123492B (en) | A kind of generation schedule optimization method a few days ago considering thermoelectricity electric heat storage combined adjusting peak | |
CN106451566B (en) | multi-source coordination control method for island intelligent microgrid | |
CN108229865A (en) | A kind of electric heating gas integrated energy system low-carbon economy dispatching method based on carbon transaction | |
CN113850474B (en) | Thermoelectric hydrogen multi-energy flow comprehensive energy system and optimal scheduling method thereof | |
CN112990523B (en) | Hierarchical optimization operation method for regional comprehensive energy system | |
CN110601260B (en) | Light-storage system capacity optimization method for limiting power fluctuation on interconnection line | |
CN113256045A (en) | Park comprehensive energy system day-ahead economic dispatching method considering wind and light uncertainty | |
CN114169236A (en) | Phase-change heat storage type electric heating negative control system control method based on LSTM algorithm | |
Zhao et al. | Day-ahead robust optimal dispatch of integrated energy station considering battery exchange service | |
CN112836882A (en) | Regional comprehensive energy system operation optimization method considering equipment load rate change | |
CN113078684B (en) | Regional energy community planning method based on double-layer optimization | |
CN112365034B (en) | Electric heating comprehensive energy system scheduling method and system | |
CN111969591B (en) | Off-grid hybrid energy system optimization method based on complementation of optical energy storage hydropower station | |
CN117436773A (en) | Independent micro-grid resource planning method and system containing interruptible load | |
CN110336308B (en) | Opportunity constraint-based active power distribution network economic dispatching method | |
CN116805192A (en) | Comprehensive energy system double-layer planning optimization method considering optimal energy rejection rate and application thereof | |
CN117081143A (en) | Method for promoting coordination and optimization operation of park comprehensive energy system for distributed photovoltaic on-site digestion | |
CN115765034A (en) | Photo-thermal-photovoltaic-thermal power combined cooperative control method and system | |
CN115566731A (en) | Flexible power supply planning method based on system multi-energy complementation | |
CN113159980A (en) | Optimal regulation and control method for wind-solar absorption-improving thermoelectric combined system | |
Chang et al. | Research on low-carbon economic operation strategy of renewable energy-pumped storage combined system | |
CN115051406A (en) | Multi-stage coordination control risk scheduling method considering source network uncertainty | |
CN114188942A (en) | Power grid dispatching method comprising large-scale new energy base | |
CN115882460A (en) | Two-stage new energy micro-grid optimization scheduling method considering demand side management |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
PB01 | Publication | ||
PB01 | Publication | ||
SE01 | Entry into force of request for substantive examination | ||
SE01 | Entry into force of request for substantive examination |