CN106682933A - Direct trading method considering influence factors of grid losses for cross-district and cross-province power users - Google Patents

Abstract

The invention belongs to the field of direct transaction of large electric power users, and specifically relates to a method for direct transaction of cross-regional and inter-provincial electric power users in a centralized matching mode in consideration of the influence factors of transmission network loss, specifically including: (1) establishing a cross-regional transaction method considering transmission network loss Mathematical model of cross-provincial large user direct purchase transaction; (2) measurement method of transmission network loss impact factor; (3) cross-region and cross-provincial large user direct purchase transaction ordering rules considering transmission network loss; (4) consideration of transmission network loss The process of direct transaction matching of large power users across regions and provinces with network loss. The beneficial effect of the present invention is that: the proposed cross-regional and cross-provincial large user direct purchase ordering rules can consider the influence of transmission grid loss on the premise of following the principle of "price priority, energy conservation and environmental protection priority", so that the transaction method can be further refined and more efficient It is conducive to maintaining the fairness of electricity market transactions.

Description

A cross-regional and cross-provincial power user direct transaction considering the influence factors of transmission network loss method

technical field

The invention belongs to the field of direct transaction of large electric power users, and in particular relates to a direct transaction method for cross-regional and inter-provincial electric power users in a centralized matching mode in consideration of transmission network loss influence factors.

Background technique

Cross-regional and cross-provincial large-scale user direct transactions refer to the direct transactions between power generation companies in different power grids and power users who have access to higher voltage levels and have a certain power purchase scale, and sign transaction contracts. Utilize the advantages of power grid interconnection to promote resource allocation, energy conservation and emission reduction, and ensure power balance and safe supply. The market entities for direct transactions of large users across regions and provinces are divided into electricity sellers, transmission entities, and electricity buyers. The electricity sellers are mainly power generation companies that have obtained power generation business licenses; the power transmission entities are power grids that have obtained power transmission business licenses. Enterprises; power purchasers are qualified power users. Transaction organization methods include bilateral negotiation transactions, centralized matching transactions, and centralized listing transactions. Different transaction methods have different implementation methods, but they all need to follow different rules to complete transactions. Among them, the rules and algorithms of centralized matching transactions are the most complicated. Enterprises centrally declare transaction needs through the power trading platform, and the power trading platform performs transaction matching in accordance with the principle of centralized matching and clearing. According to the principle of "price priority, energy conservation and environmental protection priority", the direct transactions of large users across provinces and regions organized by the existing centralized matching method are sorted and matched, and the power purchase allocation sequence is calculated by comprehensively considering weight factors such as declared power purchases and power purchase prices .

In order to promote the development of clean energy and meet the needs of expanding the scope of direct transactions from within the province to a wider range, it is urgent to accelerate the development of direct transactions of large users across regions and provinces. Due to the geographical differences of market members participating in direct transactions of large users across provinces and regions, the transaction volume of each market member unit has different impacts on transmission network losses, and the ordering rules for transaction bidding should also take into account the factors affecting transmission network losses.

In the existing technology, Chen Xiying, Hu Jiangyi. Discussion on the direct transaction algorithm between large users and power generation enterprises. Electric Power System Automation. 2008, 32(24): 100-103, analyzing the practical significance and research of China's large-scale direct purchase of electricity Based on the advantages and disadvantages of large users' direct purchase of electricity transactions, a large user's direct purchase of electricity transaction model under the centralized matching method is built. The objective function is to maximize social welfare, that is, "big users declare transaction costs" and "power generation enterprises declare transaction costs" The difference is the largest, and the transaction cost is the product of the declared price and the declared amount of electricity. The constraints are the balance of power generation and consumption, the amount of transaction volume in the generation quotation section, the transaction volume constraint in the electricity purchase quotation section, and the allowable access to large users. Power generation quotation and transaction price constraints, etc.

Disadvantages of the existing technology: the geographical location of market members participating in cross-regional and cross-provincial direct transactions is relatively different, and the difference in transmission network loss due to geographical location cannot be ignored. When the existing technology deals with the direct transactions of large users across regions and provinces, it does not consider the impact of transmission network loss caused by different transactions, which may easily lead to unfair electricity market transactions.

Contents of the invention

The purpose of the present invention is to consider the differences in geographic locations of market members participating in cross-regional and cross-provincial direct transactions, resulting in different impacts of the transaction volume of each market member unit on transmission network loss, to propose a network loss factor measurement method, and to propose a method that takes into account the impact of transmission network loss Large cross-regional and cross-provincial users directly submit bidding ordering rules, thereby promoting the refinement of transaction methods and maintaining the fairness of electricity market transactions. Focus on solving 2 problems:

1) The measurement of the impact of the transaction volume of each market member unit on the transmission network loss in the direct transaction of cross-regional and cross-provincial power users;

2) The ranking rules for direct bidding of cross-regional and cross-provincial power users taking into account the impact of transmission grid loss.

Technical scheme of the present invention is as follows:

1. A method for direct trading of power users across regions and provinces considering the impact factors of transmission grid loss, characterized in that the method includes the following steps:

(1) Establish a mathematical model for direct power purchase transactions of large users across regions and across provinces considering transmission grid loss

The assumption of the model: only consider the cost of network loss related to active power; the correlation between network loss and active power is stronger than that of reactive power. The more nodes in the system, the longer the calculation time. In order to speed up the calculation, the influence of reactive power is ignored ;

Assuming that the number of users in the direct purchase transaction of large users is n, the number of power generation companies is m, the purchased electricity and quotations declared by user i are Q _Bi , C _Bi , respectively, and the sales electricity and quotations declared by power generation company j are Q _Si , C _Si ;

The goal of the mathematical model for the direct purchase of large users across provinces and regions is to maximize social benefits, and the optimization variable is the transaction volume between each user and each power generation company;

Objective function:

In the formula: Q _ij is the electricity purchased by user i from power generation company j, that is, the transaction volume; a _ij is the transmission price, that is, the network fixed cost of unit transaction power between user i and power generation company j; b _ij is the impact of transmission network loss Factor, that is, the network loss cost per unit of transaction electricity between user i and power generation company j;

Restrictions:

In the formula, The maximum value of power purchased for user i, which is the declared power Q _Bi in value; is the maximum value of power sold by power generation company j, which is the declared power Q _Si in value; p _b is the power of branch b after the transaction occurs, that is, the hourly power; The maximum transmission capacity of branch b; the total number of branches of BR;

The meaning of formula (2) is that the sum of the electricity purchased by user i from all power generation companies cannot exceed its declared power; the meaning of formula (3) is that the sum of the electricity sold by power company j to all users cannot exceed its declared power; formula (4) The meaning of is that the transaction will not cause network congestion; in formula (1), the transmission price a _ij is related to the path between user i and power generation company j, and the government pricing standard is adopted. When the location of the user and power company is determined, it can be regarded as a constant; formula ( 1) The influence factor b _ij of transmission network loss is also related to the path between user i and power generation company j, which involves network power flow and needs to be studied separately;

(2) Measurement method of transmission network loss influence factor

The transmission network loss influence factor of the present invention adopts the following method:

For an N-node system, the total network loss L formula is

Network loss is a function of the injected power of each node, denoted as L(P,Q);

J is the Jaccobi matrix of the power flow equation, which can be obtained from formula (6):

In the formula, It can be obtained from the partial derivative of formula (5); λ _P = [λ _P1 ,λ _P2 ,...λ _PN ] ^T is the active marginal network loss coefficient vector of each node; λ _Q =[λ _Q1 ,λ _Q2 ,. ..λ _QN ] ^T is the reactive power marginal network loss coefficient vector of each node;

For PV node i, the variable amount of reactive power of this node will be fully compensated by this node, so no additional network loss will be caused, that is, λ _Qi = 0; similarly, for balanced node S, λ _PS = λ _QS = 0;

Generally speaking, the total network loss of the system in the transmission network is mainly caused by active power, while the network loss caused by reactive power only accounts for a small part, so equation (8) can be further simplified as

The network loss caused by the unit electricity transaction between user i and power generation company j is

l _ij =λ _Pi -λ _Pj (10)

Considering the change of power grid operation mode and avoiding frequent adjustment of transmission network loss influence factors, calculate L _ij for M typical operation modes respectively, and take the average value of transmission network loss influence factor b _ij , namely

(3) Sorting rules for cross-regional and cross-provincial large-scale direct purchase transactions considering transmission grid loss

The ordering principle of matching transactions is as follows: the direct transactions of large users across provinces and regions organized by centralized matching are sorted and matched according to the principle of "price priority, energy conservation and environmental protection priority"; 1) After considering the influence factors of transmission price and transmission loss, first Match buyers and sellers with the highest price difference, and then the next highest until there is no transaction power; 2) Under the condition of the same price difference, power generation companies are sorted according to the principle of energy conservation and environmental protection, first wind/solar/water clean energy units, then thermal power units, first thermal power After the large unit, the small thermal power unit;

The criteria for the end of the matching transaction are: 1) All the sold power declared by all sellers has been traded; 2) All the purchased power declared by all buyers has been traded; 3) The unsold sellers’ quotations are higher than the unsettled buyers’ quotations .

(4) The process of direct transaction matching of large power users across regions and provinces considering transmission grid loss

The transaction process of the direct purchase of large users across provinces and regions in consideration of the loss of the transmission network proposed by the present invention is as follows:

8) The power trading center needs to release the information that should be submitted on the trading day to the trading subject 5 working days in advance, such as trading electricity, price, time, etc.;

9) Based on the principle of equality and voluntariness, the trading entities submit their own declaration information, including basic parameters such as declared electricity and declared quotations of both buyers and sellers;

10) The power trading center calculates the loss factor of the transmission network between nodes;

11) The power trading center forms a transaction matching table according to 5.3.1 based on the information submitted by each trading entity;

12) The power trading center forms an initial transaction queue in accordance with 5.3.2;

13) The power trading center corrects the transaction queue according to 5.3.3, forms the final matching transaction plan, determines each transaction subject and its transaction volume, and the transaction price is determined according to the middle price between the buyer and the seller;

14) After the security check, a bound transaction clearing result is formed.

Further, in the step (3), according to the ordering principle of matching transactions, the criterion of the end of the transaction, and considering the transmission price and the loss factor of the transmission network, the generation of the ordering rules for the direct purchase transactions of large users across regions and provinces proposed by this application mainly includes: 3 links: establish a transaction matching table; establish an initial transaction queue; modify the transaction queue; the details are as follows:

(1) Establish a transaction matching table

For n large users and m power generation companies participating in the transaction, a transaction matching table T with a scale of n*m is constructed with large users as rows and power generation companies as columns; for T, large users (i=1, 2,. .., n) Sort by declared price C _Bi from high to low; the column sorts power generation companies (j=1, 2,..., m) by declared price C _Sj from low to high;

The element T _ij in row i and column j is the difference between the price quoted by the large user and the power generation company after considering the transmission price and network loss. If the buyer and large user bear the cost of power transmission and network loss, then C' _Bi = C _Bi -a _ij -b _ij , C' _Sj ＝C _Sj , then T _ij ＝C' _Bi -C' _Sj ＝C _Bi -C _Sj -a _ij -b _ij ; T _ij <0 means that the corrected price of power purchase by large users is lower than that of electricity sales by power generation enterprises price, the transaction will have a negative social contribution and will not be matched; T _ij = 0 means that the revised price of electricity purchased by large users is equal to the electricity sales price of power generation companies, and the transaction will have zero social contribution and will not be matched; T _ij >0 Indicates that the revised price of power purchase by large users is greater than the price of electricity sold by power generation companies, then the transaction is positive for social contribution and can be matched;

(2) Establish an initial transaction queue

Form the initial transaction queue Z according to the transaction matching table T;

3) Scan each element in T line by line, skip if T _ij <0 or T _ij =0, and add T _ij to queue Z' if T _ij >0;

4) Arrange the values of each element in Z' in descending order from large to small to form the initial transaction queue Z. If the values are the same, the transactions related to energy-saving and environmental protection units will be placed first;

3) Record the large user and power generation enterprise number i, j (corresponding to the row and column of T) corresponding to each element of Z and their respective declared electric quantities Q _Bi , Q _Sj ;

4) Assume that large users and power generation enterprises have currently completed transaction power RQ _Bi = 0 (i = 1, 2, ..., n), RQ _Sj = 0 (j = 1, 2, ..., m);

(3) Modify the transaction queue

The elements in Z are scanned one by one from small to large according to the serial number, and the transaction queue is continuously corrected in the process, and the transaction power is determined at the same time;

1) Read the number i and j of the large user and power generation company corresponding to the current element;

2) Determine the transaction power corresponding to the current element as min{Q _Bi -RQ _Bi ,Q _Sj -RQ _Sj };

3) Correct the currently completed transaction power of large users RQ _Bi = RQ _Bi +min{Q _Bi -RQ _Bi ,Q _Sj -RQ _Sj }, and correct the current completed transaction power of power companies RQ _Sj =RQ _Sj +min{Q _Bi - RQ _Bi ,Q _Sj -RQ _Sj };

4) If RQ _Bi ＝Q _Bi , it means that all the declared transaction electricity of big user i is completed, then delete all the elements related to big user i after the current element in Z; if RQ _Sj ＝Q _Sj , it means all declarations of power company j After the electricity transaction is completed, delete all elements related to power company j after the current element in Z;

5) Update Z.

According to the above matching transaction sorting rules, all successful matching transactions can be obtained according to the revised transaction queue Z, and the corresponding power consumption of each transaction can be determined; in this process, the transaction sorting principle and the transaction end criterion are naturally satisfied, and also The solution of step (1) "mathematical model of direct power purchase transaction for large users across provinces and regions considering transmission grid loss" is automatically realized.

The beneficial effects of the present invention are:

1) The proposed cross-regional and cross-provincial large-scale user direct transaction model takes into account the influence of transmission network loss factors;

2) The proposed measurement method for the influence factor of transmission network loss comprehensively considers various operation modes of the power grid, and the calculation result is relatively stable, which can be solidified as an empirical value and is convenient for practical application;

3) Under the premise of complying with the principle of "price priority, energy conservation and environmental protection priority", the proposed cross-regional and cross-provincial large user direct purchase transaction ordering rules can consider the impact of transmission grid loss, making the transaction method further refined, and more conducive to maintaining the electricity market Transaction fairness.

Description of drawings

Fig. 1 is a flow chart of transaction matching in the present invention.

detailed description

The technical solution of the present invention will be described in detail below in conjunction with the accompanying drawings.

1. A method for direct trading of power users across regions and provinces considering the impact factors of transmission grid loss, characterized in that the method includes the following steps:

(1) Establish a mathematical model for direct power purchase transactions of large users across regions and across provinces considering transmission grid loss

The assumption of the model: only consider the cost of network loss related to active power; the correlation between network loss and active power is stronger than that of reactive power. The more nodes in the system, the longer the calculation time. In order to speed up the calculation, the influence of reactive power is ignored ;

Assuming that the number of users in the direct purchase transaction of large users is n, the number of power generation companies is m, the purchased electricity and quotations declared by user i are Q _Bi , C _Bi , respectively, and the sales electricity and quotations declared by power generation company j are Q _Si , C _Si ;

The goal of the mathematical model for the direct purchase of large users across provinces and regions is to maximize social benefits, and the optimization variable is the transaction volume between each user and each power generation company;

Objective function:

In the formula: Q _ij is the electricity purchased by user i from power generation company j, that is, the transaction volume; a _ij is the transmission price, that is, the network fixed cost of unit transaction power between user i and power generation company j; b _ij is the impact of transmission network loss Factor, that is, the network loss cost per unit of transaction electricity between user i and power generation company j;

Restrictions:

In the formula, The maximum value of power purchased for user i, which is the declared power Q _Bi in value; is the maximum value of power sold by power generation company j, which is the declared power Q _Si in value; p _b is the power of branch b after the transaction occurs, that is, the hourly power; The maximum transmission capacity of branch b; the total number of branches of BR;

The meaning of formula (2) is that the sum of the electricity purchased by user i from all power generation companies cannot exceed its declared power; the meaning of formula (3) is that the sum of the electricity sold by power company j to all users cannot exceed its declared power; formula (4) The meaning of is that the transaction will not cause network congestion; in formula (1), the transmission price a _ij is related to the path between user i and power generation company j, and the government pricing standard is adopted. When the location of the user and power company is determined, it can be regarded as a constant; formula ( 1) The influence factor b _ij of transmission network loss is also related to the path between user i and power generation company j, which involves network power flow and needs to be studied separately;

(2) Measurement method of transmission network loss influence factor

According to circuit theory, network losses cannot be calculated using the superposition principle. Therefore, the method of determining the influence factors of transmission network loss cannot be established on a strict theoretical basis. The determination of transmission network loss influencing factor b _ij should follow: ① reflect the degree of each user’s utilization of the network as truly as possible; ② provide correct economic signals to guide the optimal allocation of resources; Fixed, avoid frequent adjustments; ④ The trend based on it should be as consistent as possible with the real trend.

The transmission network loss influence factor of the present invention adopts the following method:

For an N-node system, the total network loss L formula is

Network loss is a function of the injected power of each node, denoted as L(P,Q);

J is the Jaccobi matrix of the power flow equation, which can be obtained from formula (6):

In the formula, It can be obtained from the partial derivative of formula (5); λ _P = [λ _P1 ,λ _P2 ,...λ _PN ] ^T is the active marginal network loss coefficient vector of each node; λ _Q =[λ _Q1 ,λ _Q2 ,. ..λ _QN ] ^T is the reactive power marginal network loss coefficient vector of each node;

For PV node i, the variable amount of reactive power of this node will be fully compensated by this node, so no additional network loss will be caused, that is, λ _Qi = 0; similarly, for balanced node S, λ _PS = λ _QS = 0;

Generally speaking, the total network loss of the system in the transmission network is mainly caused by active power, while the network loss caused by reactive power only accounts for a small part, so equation (8) can be further simplified as

The network loss caused by the unit electricity transaction between user i and power generation company j is

l _ij =λ _Pi -λ _Pj (10)

Considering the change of power grid operation mode and avoiding frequent adjustment of transmission network loss influence factors, calculate L _ij for M typical operation modes respectively, and take the average value of transmission network loss influence factor b _ij , namely

(3) Sorting rules for cross-regional and cross-provincial large-scale direct purchase transactions considering transmission grid loss

The ordering principle of matching transactions is as follows: the direct transactions of large users across provinces and regions organized by centralized matching are sorted and matched according to the principle of "price priority, energy conservation and environmental protection priority"; 1) After considering the influence factors of transmission price and transmission loss, first Match buyers and sellers with the highest price difference, and then the next highest until there is no transaction power; 2) Under the condition of the same price difference, power generation companies are sorted according to the principle of energy conservation and environmental protection, first wind/solar/water clean energy units, then thermal power units, first thermal power After the large unit, the small thermal power unit;

The criteria for the end of the matching transaction are: 1) All the sold power declared by all sellers has been traded; 2) All the purchased power declared by all buyers has been traded; 3) The unsold sellers’ quotations are higher than the unsettled buyers’ quotations .

According to a method for direct transaction of cross-regional and inter-provincial power users that considers the influence factors of transmission grid loss described in claim 1, the generation of the ordering rules for direct purchase transactions of large-scale cross-regional and inter-provincial users proposed in this application mainly includes three links: establishing transactions Matching table; establish the initial transaction queue; modify the transaction queue; the details are as follows:

(3.1) Establish a transaction matching table

For n large users and m power generation companies participating in the transaction, a transaction matching table T with a scale of n*m is constructed with large users as rows and power generation companies as columns; for T, large users (i=1, 2,. .., n) Sort by declared price C _Bi from high to low; the column sorts power generation companies (j=1, 2,..., m) by declared price C _Sj from low to high;

The element T _ij in row i and column j is the difference between the price quoted by the large user and the power generation company after considering the transmission price and network loss. If the buyer and large user bear the cost of power transmission and network loss, then C' _Bi = C _Bi -a _ij -b _ij , C' _Sj ＝C _Sj , then T _ij ＝C' _Bi -C' _Sj ＝C _Bi -C _Sj -a _ij -b _ij ; T _ij <0 means that the corrected price of power purchase by large users is lower than that of electricity sales by power generation enterprises price, the transaction will have a negative social contribution and will not be matched; T _ij = 0 means that the revised price of electricity purchased by large users is equal to the electricity sales price of power generation companies, and the transaction will have zero social contribution and will not be matched; T _ij >0 Indicates that the revised price of power purchase by large users is greater than the price of electricity sold by power generation companies, then the transaction is positive for social contribution and can be matched;

Table 1 Transaction Matching Table T

(3.2) Establish an initial transaction queue

Form the initial transaction queue Z according to the transaction matching table T;

1) Scan each element in T line by line, skip if T _ij <0 or T _ij =0, and add T _ij to queue Z' if T _ij >0;

2) Arrange the values of each element in Z' in descending order from large to small to form the initial transaction queue Z. If the values are the same, the transactions related to energy-saving and environmental protection units will be placed first;

3) Record the large user and power generation enterprise number i, j (corresponding to the row and column of T) corresponding to each element of Z and their respective declared electric quantities Q _Bi , Q _Sj ;

4) Assume that large users and power generation enterprises have currently completed transaction power RQ _Bi = 0 (i = 1, 2, ..., n), RQ _Sj = 0 (j = 1, 2, ..., m);

(3.3) Modify the transaction queue

The elements in Z are scanned one by one from small to large according to the serial number, and the transaction queue is continuously corrected in the process, and the transaction power is determined at the same time;

1) Read the number i and j of the large user and power generation company corresponding to the current element;

2) Determine the transaction power corresponding to the current element as min{Q _Bi -RQ _Bi ,Q _Sj -RQ _Sj };

3) Correct the currently completed transaction power of large users RQ _Bi = RQ _Bi +min{Q _Bi -RQ _Bi ,Q _Sj -RQ _Sj }, and correct the current completed transaction power of power companies RQ _Sj =RQ _Sj +min{Q _Bi - RQ _Bi ,Q _Sj -RQ _Sj };

4) If RQ _Bi ＝Q _Bi , it means that all the declared transaction electricity of big user i is completed, then delete all the elements related to big user i after the current element in Z; if RQ _Sj ＝Q _Sj , it means all declarations of power company j After the electricity transaction is completed, delete all elements related to power company j after the current element in Z;

5) Update Z;

According to the above matching transaction sorting rules, all successful matching transactions can be obtained according to the revised transaction queue Z, and the corresponding power consumption of each transaction can be determined; in this process, the transaction sorting principle and the transaction end criterion are naturally satisfied, and also The solution of step (1) "mathematical model of direct power purchase transaction for large users across provinces and regions considering transmission grid loss" is automatically realized.

(4) The process of direct transaction matching of large power users across regions and provinces considering transmission grid loss

The transaction process of the direct purchase of large users across provinces and regions in consideration of the loss of the transmission network proposed by the present invention is as follows:

1) The power trading center needs to release the information that should be submitted on the trading day to the trading subject 5 working days in advance, such as trading power, price, time, etc.;

2) Based on the principle of equality and voluntariness, the trading entities submit their own declaration information, including basic parameters such as declared electricity and declared quotations of both buyers and sellers;

3) The power trading center calculates the loss factor of the transmission network between nodes;

4) The power trading center forms a transaction matching table according to 5.3.1 based on the information submitted by each trading entity;

5) The power trading center forms an initial transaction queue in accordance with 5.3.2;

6) The power trading center corrects the transaction queue according to 5.3.3, forms the final matching transaction plan, determines each transaction subject and its transaction volume, and the transaction price is determined according to the middle price between the buyer and the seller;

7) After the security check, a binding transaction clearing result is formed.

Claims (2)

1. it is a kind of consider Transmission Loss factor of influence the transregional direct dealing method of power consumer transprovincially, it is characterised in that it is described Method comprises the steps：

(1) Mathematical Modeling of the transregional Direct Purchase of Electric Energy by Large Users transprovincially transaction for considering Transmission Loss is set up

The supposed premise of model：Only consider the Web-based exercise related to active power；Network loss is more idle with active power correlation Power is strong, and the system node number more multioperation time is longer, is to accelerate calculating speed, ignores the impact of reactive power；

If number of users is n in Direct Purchase of Electric Energy by Large Users transaction, electricity power enterprise is m, purchase electricity and report that user i is declared Valency is respectively Q_Bi、C_Bi, electricity sales amount and quotation respectively Q that electricity power enterprise j is declared_Si、C_Si；

Transprovincially area's Direct Purchase of Electric Energy by Large Users transaction Mathematical Modeling target be social benefit maximize, optimized variable be each user with it is each Conclusion of the business electricity between electricity power enterprise；

Object function：

$\max J=\underset{i=1}{\overset{n}{\mathrm{\&Sigma;}}}\underset{j=1}{\overset{m}{\mathrm{\&Sigma;}}}\left(C_{Bi}-C_{Sj}-a_{ij}-b_{ij}\right)Q_{ij}---\left(1\right)$

In formula：Q_ijFor the electricity that user i buys to electricity power enterprise j, alternating current amount；a_ijFor Wheeling rate, i.e. user i and generating The network fixed cost of unit transaction electricity between enterprise j；b_ijFor Transmission Loss factor of influence, i.e. user i and electricity power enterprise j it Between unit conclude the business electricity Web-based exercise；

Constraints：

In formula,For the maximum that user i buys electricity, numerically to declare electricity Q_Bi；For electricity power enterprise j sales The maximum of electricity, numerically to declare electricity Q_Si；p_bThe power of branch road b, i.e. hour electricity after occurring for transaction； The maximum transfer capacity of road b；The branch road sum of BR；

The implication of formula (2) is that user i declares electricity from the electricity summation that all electricity power enterprises buy no more than it；Formula (3) Implication is that electric power enterprise j declares electricity to the electricity summation that all users sell no more than it；The implication of formula (4) is to conclude the business not Block can network；Wheeling rate a in formula (1)_ijWith user i and electricity power enterprise's j path-dependents, the standard that valorizes is adopted Then, when user, electric power enterprise position can be considered constant when determining；Formula (1) Transmission Loss factor of influence b_ijAlso with user i and generating Enterprise's j path-dependents, are related to network trend, need individually research；

(2) measure of Transmission Loss factor of influence

Transmission Loss factor of influence of the present invention is adopted with the following method：

For the total network loss L formula of N node systems is

$L=\frac{1}{2}\underset{i=1}{\overset{N}{\&Sigma;}}\underset{j=1}{\overset{N}{\&Sigma;}}{G}_{ij}\&lsqb;V_i^2+V_j^2-2V_i{V}_{j}cos({\mathrm{\&theta;}}_i-{\mathrm{\&theta;}}_j)\&rsqb;,(i=1,2,...,N)---\left(5\right)$

Network loss is the function of each node injecting power, is designated as L (P, Q)；

$\begin{array}{c}\frac{\&part;L}{\&part;\mathrm{\&theta;}}=\frac{\&part;L}{\&part;P}\frac{\&part;P}{\&part;\mathrm{\&theta;}}+\frac{\&part;L}{\&part;Q}\frac{\&part;Q}{\&part;\mathrm{\&theta;}}\\ \frac{\&part;L}{\&part;V}=\frac{\&part;L}{\&part;P}\frac{\&part;P}{\&part;V}+\frac{\&part;L}{\&part;Q}\frac{\&part;Q}{\&part;V}\end{array},\left[\begin{array}{c}\frac{\&part;L}{\&part;\mathrm{\&theta;}}\\ \frac{\&part;L}{\&part;V}\end{array}\right]=J\left[\begin{array}{c}\frac{\&part;L}{\&part;P}\\ \frac{\&part;L}{\&part;Q}\end{array}\right]---\left(6\right)$

J is the Jaccobi matrixes of power flow equation, can be obtained by formula (6)：

$J=\left[\begin{array}{cc}\frac{\&part;P}{\&part;\mathrm{\&theta;}}& \frac{\&part;Q}{\&part;\mathrm{\&theta;}}\\ \frac{\&part;P}{\&part;V}& \frac{\&part;Q}{\&part;V}\end{array}\right]=\left[\begin{array}{cc}{J}_1& J_2\\ J_3& J_4\end{array}\right]---\left(7\right)$

$\left[\begin{array}{c}{\mathrm{\&lambda;}}_P\\ {\mathrm{\&lambda;}}_Q\end{array}\right]=\left[\begin{array}{c}\frac{\&part;L}{\&part;P}\\ \frac{\&part;L}{\&part;Q}\end{array}\right]=J^{-1}\left[\begin{array}{c}\frac{\&part;L}{\&part;\mathrm{\&theta;}}\\ \frac{\&part;L}{\&part;V}\end{array}\right]---\left(8\right)$

In formula,Can be tried to achieve by the local derviation of formula (5)；λ_P=[λ_P1,λ_P2,...λ_PN]^TFor the active marginal loss of each node Coefficient vector；λ_Q=[λ_Q1,λ_Q2,...λ_QN]^TFor the idle marginal loss coefficient vector of each node；

For PV node i, the variable quantity of the node reactive power will be compensated all by the node, thus will not cause extra Network loss, i.e. λ_Qi=0；In the same manner, for balance nodes S, there is λ_PS=λ_QS=0；

In general, total network loss of system is mainly what is caused by active power in power transmission network, and the network loss that reactive power causes Small part is only accounted for, so formula (8) can be further simplified as

${\mathrm{\&lambda;}}_P=J_1^{-1}\frac{\&part;L}{\&part;\mathrm{\&theta;}}---\left(9\right)$

It is by the network loss amount that causes of unit quantity of electricity transaction between user i and electricity power enterprise j

l_ij=λ_Pi-λ_Pj (10)

In view of the change of power system operating mode, it is to avoid Transmission Loss factor of influence Jing is often adjusted, to the typical method of operation of M kinds It is respectively calculated L_ij, Transmission Loss factor of influence b_ijIts mean value is taken, i.e.,

$b_{ij}=\frac{1}{M}\underset{k=1}{\overset{M}{\&Sigma;}}{l}_{ij}^k---\left(11\right)$

(3) the transregional large user transprovincially of meter and Transmission Loss directly purchases transaction ordering rule

Trade matching principle of ordering is：Concentration bring together large user transregional transprovincially direct dealing that mode organizes according to " price priority, Energy-conserving and environment-protective are preferential " principle be traded sequence and match；1) consider after Wheeling rate, Transmission Loss factor of influence, first Bring buyer and seller price differential soprano together, it is then secondary high until no deal electricity；2) under the conditions of price differential identical, electricity power enterprise presses It is ranked up according to the principle of energy-conserving and environment-protective, fired power generating unit after first wind/light/water clean energy resource unit, thermoelectricity after first thermoelectricity large-sized unit Little unit；

Trade matching ending-criterion is：1) what all sellers were declared go out electricity sales amount all concludes the business；2) all buyer institutes Shen The electricity of buying of report is all concluded the business；3) seller price quotations not struck a bargain are higher than the buyer's quotation not struck a bargain；

(4) consider that process is brought in the transregional larger power user transprovincially direct dealing of Transmission Loss together

The Direct Purchase of Electric Energy by Large Users trade matching process of area transprovincially for considering Transmission Loss proposed by the present invention is as follows：

1) power exchange needs the information that in advance 5 working days should submit to the transaction agent issue transaction same day, such as concludes the business Electricity, price, time etc.；

2) itself voluntary principle of equality, transaction agent submit to it is respective declares information, including purchase sell both sides declare electricity, Shen The basic parameters such as report quotation；

3) power exchange calculates the Transmission Loss factor between each node；

4) information that power exchange is submitted to according to each transaction agent, operates to form transaction and bring table together according to 5.3.1；

5) power exchange operates to form initial transaction queue according to 5.3.2；

6) power exchange forms final trade matching scheme according to 5.3.3 operation amendment transaction queues, determines each transaction master Body and its conclusion of the business electricity, conclusion of the business electricity price determines according to both parties' intermediate price；

7) Jing after Security Checking, constrained trading clearing result is formed.

2. it is according to claim 1 it is a kind of consider Transmission Loss factor of influence transregional power consumer direct dealing side transprovincially Method, it is characterised in that in the step (3), according to trade matching principle of ordering, closing the transaction criterion, while considering transmission of electricity electricity Valency and the Transmission Loss factor, the transregional large user transprovincially that the application is proposed directly purchases transaction ordering rule and generates mainly 3 links： Set up transaction and bring table together；Set up initial transaction queue；Amendment transaction queue；It is specific as follows：

(1) set up transaction and bring table together

For the n large user, the m electricity power enterprise that participate in transaction, with large user as row, electricity power enterprise be row construction scale as n* Table T is brought in the transaction of m together；For T, be about to large user (i=1,2 ..., n) press declared value C_BiHigh to low sequence；Row will generate electricity Enterprise (j=1,2 ..., m) press declared value C_SjSort from low to high；

I-th row jth column element T_ijThe difference of large user and electricity power enterprise's quotation after to consider Wheeling rate, network loss, if big by buyer Burden for users is transmitted electricity and cost of losses is C'_Bi=C_Bi-a_ij-b_ij, C '_Sj=C_Sj, then T_ij=C '_Bi-C’_Sj=C_Bi-C_Sj-a_ij-b_ij； T_ij<0 represents that large user's power purchase revised rate is less than electricity power enterprise's sale of electricity price, then the transaction is negative to contribution to society, is not scooped up Close；T_ij=0 represents that large user's power purchase revised rate is equal to electricity power enterprise's sale of electricity price, then the transaction is zero to contribution to society, no Give and brining together；T_ij>0 represents that large user's power purchase revised rate is more than electricity power enterprise's sale of electricity price, then the transaction to contribution to society for just, Can bring together；

(2) initial transaction queue is set up

Table T-shaped is brought together into initial transaction queue Z according to transaction；

1) each element in T is progressively scanned, if T_ij<0 or T_ij=0 is skipped, if T_ij>0 by T_ijPlus enqueue Z '；

2) by each element value in Z ' by descending arrangement form initial transaction queue Z from big to small, the energy-conserving and environment-protective if numerical value is identical Before unit relationship trading is put；

3) the corresponding large user of Z each element, electricity power enterprise's numbering i, j (the correspondingly row, column of T) are recorded and its electricity is each declared Q_Bi、Q_Sj；

4) large user, the current complete transaction electricity RQ of electricity power enterprise are set_Bi=0 (i=1,2 ..., n), RQ_Sj=0 (j=1, 2,...,m)；

(3) transaction queue is corrected

Element in Z is scanned one by one by sequence number is ascending, transaction queue is constantly corrected in the process, while determining transaction electricity Amount；

1) the corresponding large user of currentElement, electricity power enterprise's numbering i, j are read；

2) determine that the corresponding transaction electricity of currentElement is min { Q_Bi-RQ_Bi,Q_Sj-RQ_Sj}；

3) the current complete transaction electricity RQ of large user is corrected_Bi=RQ_Bi+min{Q_Bi-RQ_Bi,Q_Sj-RQ_Sj, correct electric power enterprise Current complete transaction electricity RQ_Sj=RQ_Sj+min{Q_Bi-RQ_Bi,Q_Sj-RQ_Sj}；

If 4) RQ_Bi=Q_Bi, represent that the whole of large user i is declared transaction electricity and completed, then delete in Z after currentElement with large user I related all elements；If RQ_Sj=Q_Sj, represent that the whole of electric power enterprise j is declared transaction electricity and completed, then delete current in Z The all elements related to electric power enterprise j after element；

5) Z is updated

Perform according to above trade matching ordering rule, all brining together successfully can be obtained according to revised transaction queue Z Transaction, and can determine the corresponding electricity of every transaction；In the process, transaction principle of ordering and closing the transaction criterion nature Meet, be also automatically obtained asking for step (1) " considering the Mathematical Modeling of the Direct Purchase of Electric Energy by Large Users transaction of area transprovincially of Transmission Loss " Solution.