CN110543609A - Classification and load flow calculation method for electric heating coupling nodes of comprehensive energy system - Google Patents
Classification and load flow calculation method for electric heating coupling nodes of comprehensive energy system Download PDFInfo
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Abstract
a classification and load flow calculation method for an electrothermal coupling node of an integrated energy system comprises the following steps: 1) defining electric heating coupling nodes according to the actual physical meaning of the coupling network, obtaining possible coupling node types through analysis, and dividing the coupling nodes into 4 types according to electric heating balance nodes; 2) analyzing the optimal solution modes (4 types in total) of different systems from the angle of the type and the number of the coupling nodes, and summarizing the characteristics of the systems corresponding to the different solution modes; 3) and analyzing the characteristics of the system, and selecting an optimal load flow calculation mode according to the analysis result. The node classification method and the calculation process provided by the invention can select an optimal mode to process load flow calculation of a network coupled by any form and any coupling node number, have certain universality, better accord with actual physical meaning, ensure the optimal solution mode of the network, improve the operation speed and provide important guidance for research and operation scheduling personnel of a comprehensive energy system.
Description
Technical Field
The invention belongs to the technical field of electric power, designs a comprehensive energy system, and particularly relates to a classification and load flow calculation method for an electrothermal coupling node of the comprehensive energy system.
Technical Field
The comprehensive energy system takes a power grid as a main body and a platform, and performs coupling complementation of various energy forms. At present, an electric heating coupling system which uses a cogeneration unit as a clean energy center to perform electric heating coupling is most commonly applied, and is one of the main expression forms of a comprehensive energy system. The combined heat and power generation unit is characterized in that different qualities of energy are utilized in a gradient mode, heat energy with higher temperature and larger available energy is used for generating electricity, and low-grade heat energy with lower temperature is used for heating or refrigerating. By doing so, not only is the utilization efficiency of energy improved, but also the emission of carbide and harmful gas is reduced, and good economic benefits and social benefits are achieved.
the network analysis of the comprehensive energy system is one of important research contents in the field of energy Internet, and is a calculation basis and foundation for operation regulation and energy transaction. The load flow calculation of the comprehensive energy system is an important component of network analysis of the electric power and thermodynamic systems, and provides important guidance for scheduling operators. The method can bring the scheduling of electric energy and heat energy into a unified decision system, solve the problem that an independent power grid and an independent heat supply network cannot overcome the scheduling of the electric energy and the heat energy, and realize the optimization of the whole large system. The load flow calculation of the power system adopts an alternating current load flow model, the thermodynamic system adopts a static thermal model, and the electric heating coupling system can adopt an integral solution or interactive iteration mode.
disclosure of Invention
The invention aims at a comprehensive energy system, and an electric power system and a thermodynamic system are combined into a coupling system through a coupling component. The traditional power flow analysis method of the coupling system still has some defects: the type of element coupling has limitations; the relationship between the heat generated by the coupling element and the electrical energy is stable, rather than variable; the process of balancing heat in the heat supply network cannot occur in a mode of ordering a power supply through heat; different methods cannot be selected according to the characteristics of the system. The invention provides a concept of an electrothermal coupling node and provides a classification method of the electrothermal coupling node of a comprehensive energy system. On the basis of traditional electric-thermal coupling load flow calculation, coupling nodes are abstracted into novel nodes, the novel nodes are divided into 4 types according to the concrete physical characteristics of the coupling nodes, and an optimal solving mode is selected according to the combination of different types of nodes of the system.
The technical scheme of the invention is as follows: a classification and load flow calculation method for electric heating coupling nodes of an integrated energy system is characterized in that on the basis of electric heating coupling load flow calculation, the coupling nodes are abstracted into a node, the node is classified according to the concrete physical characteristics of the coupling nodes, and an optimal solution mode is selected according to the combination of different types of nodes in the integrated energy system to be subjected to load flow calculation.
The invention comprises the following steps:
1) Defining an electrothermal coupling node according to the actual physical meaning of the coupling network, obtaining different forms of the coupling node through analysis, and dividing the type of the coupling node according to an electrothermal balance node;
2) Analyzing from the angles of the types and the numbers of the coupling nodes, analyzing the optimal load flow calculation solving modes of different comprehensive energy systems, and summarizing the characteristics of the comprehensive energy systems corresponding to the different solving modes;
3) and analyzing the characteristics of the comprehensive energy system, and selecting an optimal load flow calculation mode according to the analysis result.
The invention provides a node classification and load flow calculation method of an electrothermal coupling node and a load flow calculation process based on the method, which are used for processing the load flow calculation problem of an integrated energy system, improving the speed of system load flow analysis of electrothermal coupling and providing quantitative reference for integrated energy scheduling personnel.
the invention discloses a classification and load flow calculation method for electrothermal coupling nodes of an integrated energy system, which can select an optimal mode to process load flow calculation of networks coupled in any form and any number of coupling nodes, has universality, better accords with actual physical meanings, ensures an optimal solution mode of the network, overcomes conservatism to a certain extent and improves the operation speed. The invention can provide important guidance for research and operation scheduling personnel of the comprehensive energy system.
Drawings
FIG. 1 is a schematic diagram of a heat supply network structure and node temperature variations;
FIG. 2 is a schematic diagram of a single-node-containing coupling network according to an embodiment of the present invention;
FIG. 3 is a schematic diagram of a coupling network including two coupling nodes according to an embodiment of the present invention;
FIG. 4 shows possible combinations of coupling points and their solutions according to the method of the present invention;
FIG. 5 is a flow chart of load flow calculation based on node type analysis according to the present invention;
Fig. 6 shows a network topology of a 9-node coupled system according to an embodiment of the present invention.
Detailed Description
The invention aims at a comprehensive energy system, and an electric power system and a thermodynamic system are combined into a coupling system through a coupling component. The traditional power flow analysis method of the coupling system still has some defects: the type of element coupling has limitations; the relationship between the heat generated by the coupling element and the electrical energy is stable, rather than variable; the process of balancing heat in the heat supply network cannot occur in a mode of ordering a power supply through heat; different methods cannot be selected according to the characteristics of the system. To this end, the present invention is directed to increase the flexibility of analysis and provide a classification method of coupling nodes by defining a new concept, coupling node type, to classify coupling nodes and classify the relationship between heat and power as variables, thereby providing a unified coupling model. In addition, the invention also introduces a calculation method based on the new classification of the coupling nodes. Simulation shows that the calculation method has wider application and higher calculation speed, and the flexibility of coupling calculation of the electric heating system is increased to a certain degree.
the present invention will be described in further detail with reference to the accompanying drawings and examples.
1. Firstly, analyzing the load flow calculation of a thermodynamic system and an electric power system:
Power system load flow calculation is a problem of solving a voltage vector of each node by a complex power given by each node of the system. Therefore, the complex power is expressed as an equation of a voltage vector of each node, and the voltage vector of each node can be solved by a Newton method, which is a nonlinear equation. The node power may be expressed as:
Consider that:
it can be derived that:
wherein i and j represent node numbers, active power P, reactive power Q, voltage amplitude V, and voltage phase angle θ, θ ij ═ θ i- θ j represents the phase angle difference between the two nodes, Yij represents the admittance between node i and node j, Gij represents the conductance between node i and node j, and Bij represents the susceptance between node i and node j. Generally, nodes are divided into balanced nodes, PQ nodes, and PV nodes. The reactive equations have no constraints on the PV nodes and only the iterative active equations are needed. After the iteration is over, the reactive power consumed by the nodes is solved by the voltage vector of each node. Similarly, the information given by the balanced node is the voltage and its phase, so the balanced node does not participate in the iteration of the equation. The PQ node then needs to iterate the active and reactive power equations simultaneously.
the heat supply network system is described with reference to the network topology of the power system, and each pipe can be regarded as a branch. The direction of flow of the fluid is the direction of branching, and the pipe connection points, heat exchange stations and heat sources are considered as nodes, forming a directed graph of the heating network.
Fluid flows from a heat source through a supply pipe into a heat load and then out through a return pipe. After the thermal load absorbs the thermal energy in the fluid, the thermal energy contained in the fluid decreases and the fluid temperature decreases. According to this process, the nodes of the thermal network are divided into three types: a thermal load node, a heat source node, and a thermal balance node. The boundary conditions of different nodes are different. The schematic diagram of the heat supply network and the variable of the node temperature are shown in figure 1. The thermal model and the liquid model of the heat supply network are comprehensively considered, and a load flow calculation model of the heat supply network can be obtained as follows:
The heat supply network information includes heat energy phi, node water pressure H, supply water temperature Ts and output water temperature To, and there are 4n + M equations in equation (4), and there are 6n + M variables (M, Mq, Ts, Tr, To, phi, H) To be determined. When 2n variables are given, the equation can be solved. Where a represents the connection matrix of the network, M represents the mass flow per second in the pipe, H represents the water pressure at the node, Mq represents the mass flow per second in the inflow node, phi represents the thermal energy absorbed or released by the node, and Ts, Tr, To represent the temperature of the mass at different locations, as shown in fig. 1. The system of nonlinear equations may be solved using newton's method.
The coupled network of the heat supply network and the power grid is solved through a simultaneous heat supply network equation and a power grid equation, however, the heat supply network and the power grid are only coupled at a coupling node, a Jacobian matrix for solving a simultaneous equation set by a Newton method is highly sparse, and the order of the equation set is greatly increased through simultaneous solution, so that the power grid and the heat supply network can be decoupled and solved through analysis of the coupling node, the operation speed is improved, and convenience is provided for an analysis system of an operation dispatcher of a coupled system.
2. Defining and classifying the node types of the electrothermal coupling nodes:
the electrothermal coupling nodes in the electrothermal coupling system can be divided into two types: one is a coupling point capable of producing both thermal and electrical energy, and the other is a coupling point that consumes one energy to produce another. The operating characteristics of all coupled components can be used for description. For some components, the relationship is fixed, but some components are indeterminate. The coefficients of the function need to be calculated and adjusted according to the actual production. This operating characteristic can be expressed as:
Where α represents an electrical thermal coupling coefficient.
The coupling unit has a total of eleven parameters. The parameters on the heat supply network side are Mq, Ts, Tr, To, phi, H, and the parameters on the power network side are P, Q, V, theta, and the electrical-thermal coupling coefficient alpha. In order to solve the problem of solving the tidal current equation of the power grid and the heat supply network, the power grid node and the heat supply network node both need two parameters, and because the electric-thermal coupling coefficient alpha and the electric-thermal conversion characteristic equation are added at the coupling node, four parameters need to be completely given, and then the tidal current equation of the coupling network can be solved. Therefore, a new node type is generated at the coupling node, which is a quadruple and contains information about the heating network, the grid and the coupling components.
the computation load is greatly increased due to the simultaneous solution of the coupling network. Therefore, it is desirable to find a reasonable classification method by which the coupling network can be decoupled. The electric balance node of the power grid and the heat balance node of the heat supply network are respectively used for balancing energy inside the system. Coupling nodes are classified into four types according to whether they balance energy at the coupling node:
(1) Unbalanced thermal and electrical energy; (2) balanced electrical energy but unbalanced thermal energy;
(3) unbalanced electrical energy but balanced thermal energy; (4) balancing the electrical energy and the thermal energy.
According to the above classification method, all possible nodes are classified as shown in table 1. Thus, there are 21 forms of nodes that may be present at the coupling node.
TABLE 1 coupling node types
3. Analyzing the influence of the type of the coupling nodes and the number of the coupling nodes on whether the network can be decoupled:
The most ideal situation is that the power grid and the heat supply network can be completely decoupled, because after being decoupled into two independent networks, a mature power flow analysis method can be adopted. An analysis of whether the network can be decoupled will be made below by discussing the number and type of coupling nodes.
(1) the coupling network only has one coupling node
When the coupling network has only one coupling node, the type of the coupling node must be one of the above 21 node forms.
1) For the first type of nodes, two information of P, phi and alpha are known, the other one can be obtained through a coupling equation, and the coupling node is decomposed into a node in a power grid and a heat source node in a heat supply network. At the moment, the power grid and the heat supply network are decoupled and become two independent networks, and the tide is solved.
2) For the second type of nodes, the coupling nodes are used as balance nodes on the side of the heat supply network, the number of the side processes of the heat supply network is equal to the variable number, the heat supply network can be solved firstly, then the power grid is solved through a coupling equation and a power equation, and the tide is solved.
3) For the third kind of nodes, the coupling nodes are used as balance nodes on the side of the power grid, the number of the side processes of the power grid is equal to the number of the variables, the power grid can be solved first, and then the solution is carried out through a coupling equation and a heat supply network equation, so that the power flow is solved.
4) for the fourth type of node, the coupling part is simultaneously used as a balance node of the power grid and the heat supply network, the power grid and the heat supply network are naturally decoupled, and the tide is solved.
In conclusion, when the power grid and the heat supply network only have one coupling node, the power grid and the heat supply network can be decoupled and solved no matter what node type is at the coupling position, and the operation scale is greatly reduced.
(2) the coupling network only has two coupling nodes
When the grid and the heat supply network have two coupled nodes, we assume that the system does not have multiple electrical or thermal balance nodes simultaneously. Then the two coupling nodes may appear in several combinations:
TABLE 2 possible combinations of two coupling points
how the 5 combination methods are solved is discussed below:
1) Combination mode 1: the combination mode 1 is that a type 1 point is selected at both coupling points, the type 1 has 12 specific node types, so the combination 1 comprises 144 specific combinations. The 144 kinds of specific combinations are characterized in that two coupling points know two information of the three information of P, phi and alpha, and the other information can be obtained through a coupling formula. Therefore, the two coupling points are respectively decomposed into a node in a power grid and a heat source node in a heat supply network, the heat supply network and the power grid are decoupled, and the tide is resolved.
2) combination mode 2: the combination mode 2 is that the two coupling nodes respectively take the points of type 1 and type 2, the type 1 has 12 specific node types, the type 2 has 4 specific node types, so the combination 2 comprises 48 specific combinations. The characteristics of the 24 specific types are that one coupling point contains heat balance node information, and the other coupling point knows two information of the three information of P, phi and alpha and can obtain the other information through a coupling formula. For the characteristics, as the information that the type 1 node contains the heat source node is known, the heat supply network is solved to obtain a phi value of the heat balance node, and the P or alpha to be solved by the node is solved through a coupling formula, so that the power flow of the power grid can be solved, the heat supply network and the power grid are decoupled, and the power flow is solved.
3) Combination mode 3: the combination mode 3 is that the type 1 and type 3 points are respectively taken from two coupling nodes, the type 1 has 12 specific node types, the type 3 has 4 specific node types, and therefore the combination 3 comprises 48 specific combinations. The 12 specific types are characterized in that one coupling point contains electric balance node information, the other coupling point knows two information of the three information of P, phi and alpha, and the other information can be obtained through a coupling formula. For the characteristics, as the type 1 node is known to contain the information of the power grid node, the power grid is solved to obtain the P value of the electric balance node, and phi or alpha to be solved by the node is solved through a coupling formula, so that the power flow solution can be carried out on the heat supply network, the heat supply network is decoupled from the power grid, and the power flow is solved.
4) combination mode 4: the combination mode 4 is to take the points of type 1 and type 4 at two coupling nodes respectively, the type 1 has 12 specific node types, the type 4 has 1 specific node type, so the combination 4 includes 12 specific combinations. The 12 specific types are characterized in that one coupling point simultaneously contains information of electric balance nodes and thermal balance nodes, and the other coupling point knows two information of the three information of P, phi and alpha and can obtain the other information through a coupling formula. For the characteristics, the two coupling points are respectively decomposed into a node in a power grid and a heat source node in a heat supply network, the heat supply network and the power grid are decoupled, and the tide is solved.
5) Combination 5: the combination mode 5 is that the points of type 1 and type 4 are respectively taken from two coupling nodes, the type 1 has 12 specific node types, the type 4 has 1 specific node type, and therefore the combination 4 comprises 12 specific combinations. The method is divided into the following four types according to the difference of alpha information contained in two nodes:
TABLE 3 concrete Classification of combination 5
Combination 5-1: neither coupling node is aware of P and phi, so that direct decoupling solution cannot be realized, and iterative solution is required.
Combination 5-2: the number of the side processes of the power grid is equal to the unknown number, the power grid side is solved to obtain a value P of the electric balance point, phi is solved through a coupling equation, at the moment, the number of the side processes of the heat supply network is equal to the unknown number, and the value phi and alpha of the heat balance point are obtained. The heat supply network and the power grid are decoupled, and the tide is solved.
Combination 5-3: the number of the side processes of the heat supply network is equal to the unknown number, the heat supply network side is firstly solved to obtain a value phi of the heat balance point, P is solved through a coupling equation, and the number of the side processes of the power supply network is equal to the unknown number at the moment, so that the value P and the value alpha of the heat balance point are obtained. The heat supply network and the power grid are decoupled, and the tide is solved.
Combination 5-4: the two coupling points are respectively decomposed into a node in a power grid and a heat source node in a heat supply network, the heat supply network and the power grid are decoupled, and the tide is resolved.
in summary, when the power grid and the heat supply network have two coupling nodes, there are 268 specific combinations, of which 264 types can be obtained through power grid and heat supply network decoupling operations, and only 4 types need to be iteratively solved. The specific combination and its solution are shown in fig. 4. And the condition that the iterative solution is needed is that the two coupling nodes respectively contain the information of the electric balance node and the thermal balance node and the coupling nodes know alpha. In addition, the other 264 cases can be subjected to decoupling solution, and the solution is divided into two calculation methods, namely, first heating network and then power grid, and first power grid and then heating network. In all cases of decoupling, one coupling node is divided into a power grid node and a heat supply network node, the problem is converted into a power flow solving problem only comprising one coupling node, and a system only comprising one coupling node can be subjected to decoupling operation.
(3) The power grid and the heat supply network have three or more coupling nodes
since it is assumed that the system does not have a plurality of electrically balanced nodes or thermally balanced nodes at the same time, when three or more coupled nodes are present, the type 1 coupled node must be added on the basis of the two coupled nodes. While the node of type one knows P, phi, alpha, so that the coupled node can be decomposed into a grid node and a heat supply network node. This problem translates into a flow solving problem for two coupled nodes.
Therefore, the system with multiple coupled nodes needs to be solved iteratively with the following conditions: on the premise that the system only has one electric balance node and one thermal balance node, two nodes exist in the coupling node and respectively contain information of the electric balance node and the thermal balance node, and the coupling node knows alpha. In addition, the other situations can decompose the coupling node into a heat supply network node and a power grid node, convert the coupling node into the situation of one coupling node, and select the calculation mode of firstly heating the power grid and then heating the power grid and firstly heating the power grid and then heating the power grid by judging the equation number of the power grid and the heat supply network.
4. Determining a new calculation process according to different combination characteristics of the types of the coupling nodes:
From the analysis of the section of analyzing the influence of the type and the number of the coupling nodes on the decoupling of the network, the system with more than two coupling points can be simplified into a system with two coupling points for analyzing the electric-thermal coupling network coupled by the power grid and the heat supply network. While only 4 of the 268 coupling point combinations require iterative solution. Therefore, whether decoupling solution can be carried out or not can be judged by adopting a new calculation process, instead of carrying out simultaneous iterative solution on all the situations, and the calculation speed of load flow calculation is greatly increased.
The specific process is as follows:
(1) Inputting data of a power grid and a heat supply network, and inputting the number n of coupling nodes, the number m of the coupling nodes of the type 1 and the number r of the type 4.
(2) Judging whether r is equal to 1, if so, indicating that all the coupling nodes of the coupling system consist of 1 type 4 node and n-1 type 1 nodes, naturally decoupling the system, and turning to (5); if equal to 0, go to (3).
(3) all type-node decoupling, calculating P and phi, and calculating the difference between the total number of coupling nodes and the number of type 1, namely X is n-m.
(4) And if X is equal to 0, rotating to (5). If X is 1, it is described that only type 2 or type 3 nodes are included in addition to node type 1, if type two turns (6), if type 3 turns (7). If X is 2, the description also includes one each of the type 2 and 3 coupling nodes, and if both nodes contain α, go (8); if type 2 contains alpha, type 3 does not contain alpha, turning to (6); if type 3 contains alpha and type 2 does not contain alpha, turning to (7); if not, turning to (5).
(5) Decoupling solution is carried out, and the power grid heat supply network can be respectively calculated. And (9) turning.
(6) and solving the heat supply network and then solving the power grid, and performing decoupling operation. And (9) turning.
(7) and solving the power grid, then solving the heat supply network and performing decoupling operation. And (9) turning.
(8) Simultaneous equations and iterative solution. And (9) turning.
(9) And outputting a calculation result, and finishing the load flow solving.
The flow chart is shown in fig. 5. The calculation process can ensure that the simultaneous power grid heat supply network equation is selected only when iterative solution calculation is necessary, and iterative solution is carried out. In addition, for the decoupling network which can be directly decoupled or can be decoupled by selecting the prior-calculation heat supply network or the prior-calculation power grid, the most appropriate decoupling mode is adopted for decoupling solution. I.e. for any network coupled in any form and any number of coupled nodes, the solution can be performed in an optimal way by analyzing the type of coupled nodes and selecting a new calculation procedure.
Simulation analysis
1. Comparing the traditional simultaneous iterative solution with the combination 1 and the combination 4 with a computing process based on coupling node classification:
The method provided by the invention is tested by adopting a 9-node system, wherein the system has 4 power grid nodes and 5 heat supply network nodes. The four nodes of the power grid comprise two load nodes and two power supply nodes, and the four nodes of the heat supply grid comprise 2 power supply nodes and 3 load nodes. The network topology is shown in fig. 6.
in this embodiment, the node 3 of the power grid is coupled with the node 5 of the heat supply network to serve as an electric heating coupling node, and the node is a type 4 node, and meanwhile, the electric energy and the heat energy of the system are balanced. The calculation results are shown in table 4.
TABLE 4 Simultaneous iterative solution and comparison of calculation results based on coupled node classification
| Network parameters | Traditional simultaneous solution | Coupled node classification solution | error of the measurement |
| |V1| | 1.0183 | 1.0183 | 0.0000 |
| |V2| | 1.0084 | 1.0084 | 0.0000 |
| θ1 | -3.3637 | -3.3637 | 0.0000 |
| θ2 | -2.3165 | -2.3165 | 0.0000 |
| θ3 | -3.4326 | -3.4326 | 0.0000 |
| Ts1 | 98.0786 | 98.0786 | 0.0000 |
| Ts2 | 97.6787 | 97.6787 | 0.0000 |
| Ts3 | 97.7787 | 97.7787 | 0.0000 |
| φ4 | 0.6389 | 0.6389 | 0.0000 |
| P4 | 0.0856 | 0.0856 | 0.0856 |
The network can be directly decoupled because only the coupling nodes of the node type 1 and the node type 4 are included, elements for representing the coupling of the power grid and the heat supply network in the jacobian matrix of simultaneous solution are all 0, so that the matrix can be solved in a blocking mode, the calculation results of the two methods are completely the same, and the decoupling accuracy is also proved. The simultaneous calculation is carried out for 4 times, the decoupling calculation is carried out for 7 times (3 times for the power grid and 4 times for the heat grid), but the calculation amount and the calculation time of each iteration are greatly smaller than those of the simultaneous solution. Therefore, the method has advantages over the conventional algorithm in processing the networks of combination 1 and combination 4, and the advantage of the operation speed is more obvious as the network scale is increased.
2. And comparing the traditional simultaneous iterative solution with the combination 2 and the combination 5-2 with a computing process based on the coupling node classification:
in this embodiment, the grid node 4 and the heat supply network node 4 are coupled as a type two node, and the heat supply network node 4 is a heat balance node. Therefore, a decoupling method of solving the heat supply network firstly and then solving the power grid is adopted through a calculation process based on the coupling node classification.
TABLE 5 Simultaneous iterative solution and comparison of calculation results based on coupled node classification
| Network parameters | Traditional simultaneous solution | coupled node classification solution | Absolute value of error |
| |V2| | 1.0065 | 1.0065 | 0.0000 |
| |V3| | 1.0134 | 1.0134 | 0.0000 |
| θ1 | -2.9326 | -2.9312 | 0.0014 |
| θ2 | -2.1637 | -2.1634 | 0.0003 |
| θ3 | -2.5618 | -2.5623 | 0.0005 |
| Ts1 | 98.2649 | 98.2642 | 0.0007 |
| Ts2 | 97.3787 | 97.379 | 0.0008 |
| Ts3 | 96.9363 | 96.9374 | 0.0011 |
| φ4 | 0.8321 | 0.8325 | 0.0004 |
| P1 | 0.0766 | 0.0758 | 0.0008 |
in the embodiment, the network can be decoupled by solving the heat supply network first and then solving the power grid, and the maximum error of the calculation results of the two methods is 10-3 orders of magnitude, so that the accuracy requirement of load flow calculation is met. The simultaneous calculation is carried out for 5 times of iteration, the decoupling calculation is carried out for 7 times of iteration (3 times of power grid and 4 times of heat grid), but the operation amount and the operation time of each iteration are greatly smaller than those of the simultaneous solution. Therefore, the method has the advantages over the traditional algorithm in processing the networks of the combination 2 and the combination 5-2, and the advantage of the operation speed is more obvious as the network scale is increased.
For the combination 3 and the combination 5-3, decoupling can be realized by solving the power grid first and then solving the heat supply network, and the maximum error of the calculation results of the two methods is still 10-3 orders of magnitude, so that the accuracy requirement of load flow calculation is met. Similar to combination 2 and combination 5-2, the processing method has a significant advantage in speed for combination 3 and combination 5-3.
For the network which can not be decoupled and solved, the two methods are simultaneous equation iterative solution, and the calculation speed is the same. The flow calculation method based on node classification is adopted, for 268 specific combinations, only 4 combinations have the same speed as the simultaneous solution, and the calculation speed of the other 264 combinations is faster than that of the simultaneous solution.
in a word, the invention provides a classification and load flow calculation method for an electrothermal coupling node of an integrated energy system. On the basis of load flow calculation of a traditional electric heating coupling system, the type of an electric heating coupling node is defined according to the actual physical meaning of a coupling network, the optimal solution modes of different systems are analyzed from the aspects of the type and the number of the coupling nodes, the characteristics of the systems corresponding to the different solution modes are summarized, finally, a set of new calculation flow is provided, the characteristics of the systems are analyzed firstly, and the optimal load flow calculation mode is selected according to the analysis result. The simulation test is carried out on the 4 models by adopting the 9-node coupling system calculation example, and compared with the traditional electric heating coupling system load flow calculation mode, the result shows that three systems with four characteristics can obtain higher calculation speed, and the calculation error is ensured to be within an allowable range.
Claims (6)
1. A method for classifying electrothermal coupling nodes of an integrated energy system and calculating power flow is characterized in that the coupling nodes are abstracted into a node on the basis of electrothermal coupling power flow calculation, the node is classified according to the concrete physical characteristics of the coupling nodes, and an optimal solution mode is selected according to the combination of different types of nodes in the integrated energy system to be subjected to power flow calculation.
2. The classification and load flow calculation method for the electrothermal coupling nodes of the integrated energy system according to claim 1, which comprises the following steps:
1) Defining an electrothermal coupling node according to the actual physical meaning of the coupling network, obtaining different forms of the coupling node through analysis, and dividing the type of the coupling node according to an electrothermal balance node;
2) analyzing from the angles of the types and the numbers of the coupling nodes, analyzing the optimal load flow calculation solving modes of different comprehensive energy systems, and summarizing the characteristics of the comprehensive energy systems corresponding to the different solving modes;
3) And analyzing the characteristics of the comprehensive energy system, and selecting an optimal load flow calculation mode according to the analysis result.
3. the classification and load flow calculation method for the electrothermal coupling nodes of the integrated energy system according to claim 2, wherein the step 1) comprises the following steps:
101) Abstracting the electric heating coupling node into a node of the network according to the actual physical meaning;
102) Analyzing coupling node information, and determining the representation form of the coupling node as a quadruple, wherein the quadruple comprises power grid information, heat supply network information and electric-thermal coupling information, the power grid information comprises active power P, reactive power Q, voltage amplitude V and voltage phase angle theta, the heat supply network information comprises heat energy phi, node water pressure H, water supply temperature Ts and water outlet temperature To, and the electric-thermal coupling information refers To an electric-thermal conversion coefficient alpha;
103) Enumerating the possible information contained in the quadruple, and screening out the impossible situations to obtain 21 node information combinations;
104) the 21 types of node information are classified into 4 types according to whether the node information contains network balance node information: type 1 unbalanced thermal and electrical energy, type 2 balanced electrical energy but unbalanced thermal energy, type 3 unbalanced electrical energy but balanced thermal energy, and type 4 balanced electrical and thermal energy simultaneously.
4. The classification and load flow calculation method for the electrothermal coupling nodes of the integrated energy system according to claim 3, wherein the step 2) comprises the following steps:
201) respectively analyzing the comprehensive energy system containing the single coupling nodes of the four node types one by one, and determining that the single coupling node system is directly solved through decoupling operation;
202) Analyzing a coupling system containing two types of coupling nodes and more than two types of coupling nodes, enumerating all possible combination types of the four types of coupling nodes, and analyzing one by one: and 268 specific combinations are obtained through analysis, wherein four combinations need iterative solution, and the rest combinations can be subjected to decoupling solution and are divided into three decoupling modes, namely natural decoupling, calculation of the heat supply network first and then calculation of the power grid decoupling, and calculation of the power grid first and then calculation of the heat supply network decoupling.
5. the classification and load flow calculation method for the electrothermal coupling nodes of the integrated energy system according to claim 4, wherein the step 3) comprises the following steps:
301) inputting data of a power grid and a heat supply network and data of the number of coupling nodes into a comprehensive energy system to be subjected to load flow calculation to obtain the number of the coupling nodes of various node types;
302) and judging the characteristics of the comprehensive energy system according to the input information, and selecting a corresponding calculation method to ensure that only a system which needs iterative solution can select iterative solution, or else, selecting a proper decoupling method for decoupling solution.
6. The method for classifying the electrothermal coupling nodes of the comprehensive energy system and calculating the power flow as claimed in claim 5, wherein the specific process is as follows:
(a) inputting data of a power grid and a heat supply network, and inputting the number n of coupling nodes, the number m of the type 1 coupling nodes and the number r of the type 4 coupling nodes;
(b) Judging whether r is equal to 1, if the r is equal to 1, indicating that all the coupling nodes of the coupling system consist of 1 type 4 node and n-1 type 1 nodes, naturally decoupling the system, and turning to (e); if equal to 0, go to (c);
(c) decoupling all type-one nodes, calculating P and phi, and calculating the difference between the total number of coupled nodes and the number of type 1, namely X is n-m;
(d) If X is 0, go (e), if X is 1, it indicates that only type 2 or type 3 nodes are included except for node type 1, if type two go (f), if type 3 go (g); if X is 2, the description also includes one each of the type 2 and 3 coupled nodes, if both nodes contain α, turn (h); if type 2 contains alpha and type 3 does not contain alpha, turning to (f); if type 3 contains α, type 2 does not contain α, convert (g); if not, turning to (e);
(e) Decoupling solution, wherein the power grid heat supply network can be respectively calculated, and (i) is carried out;
(f) solving the heat supply network and then solving the power grid, decoupling operation, and turning to (i);
(g) Solving the power grid and then solving the heat supply network, decoupling operation, and turning to (i);
(h) Simultaneous equations, iterative solution, and (i) conversion;
(i) and outputting a calculation result, and finishing the load flow solving.
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Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111310310A (en) * | 2020-01-20 | 2020-06-19 | 东南大学 | Thermodynamic system static power flow fast decoupling calculation method for quantity adjustment |
| CN111340271A (en) * | 2020-02-13 | 2020-06-26 | 清华大学 | Electricity-heat multi-energy flow system optimal scheduling method based on heat supply phasor model |
| CN111555285A (en) * | 2020-04-03 | 2020-08-18 | 浙江工业大学 | Energy flow decoupling analysis and calculation method for distributed combined cooling heating and power comprehensive energy system |
| CN112751341A (en) * | 2020-12-29 | 2021-05-04 | 天津大学合肥创新发展研究院 | Island hydrogen-containing comprehensive energy system time sequence load flow calculation method considering energy coupling |
| WO2021164454A1 (en) * | 2020-02-22 | 2021-08-26 | 清华大学 | Heat supply network waterway modeling method for comprehensive energy system scheduling |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20120089264A1 (en) * | 2007-08-27 | 2012-04-12 | Patel Sureshchandra B | System and method of loadflow calculation for electrical power system |
| CN109347107A (en) * | 2018-09-29 | 2019-02-15 | 河海大学 | One kind be incorporated into the power networks electric heating interconnection integrated energy system tidal current computing method |
-
2019
- 2019-09-05 CN CN201910837395.3A patent/CN110543609B/en active Active
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20120089264A1 (en) * | 2007-08-27 | 2012-04-12 | Patel Sureshchandra B | System and method of loadflow calculation for electrical power system |
| CN109347107A (en) * | 2018-09-29 | 2019-02-15 | 河海大学 | One kind be incorporated into the power networks electric heating interconnection integrated energy system tidal current computing method |
Non-Patent Citations (1)
| Title |
|---|
| 时庆等: "基于综合潮流的电热耦合***分布式能源规划", 《湖北电力》 * |
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN111310310A (en) * | 2020-01-20 | 2020-06-19 | 东南大学 | Thermodynamic system static power flow fast decoupling calculation method for quantity adjustment |
| CN111310310B (en) * | 2020-01-20 | 2024-01-16 | 东南大学 | Thermodynamic system static state trend rapid decoupling calculation method for quantity adjustment |
| CN111340271A (en) * | 2020-02-13 | 2020-06-26 | 清华大学 | Electricity-heat multi-energy flow system optimal scheduling method based on heat supply phasor model |
| CN111340271B (en) * | 2020-02-13 | 2022-04-08 | 清华大学 | Electricity-heat multi-energy flow system optimal scheduling method based on heat supply phasor model |
| WO2021164454A1 (en) * | 2020-02-22 | 2021-08-26 | 清华大学 | Heat supply network waterway modeling method for comprehensive energy system scheduling |
| CN111555285A (en) * | 2020-04-03 | 2020-08-18 | 浙江工业大学 | Energy flow decoupling analysis and calculation method for distributed combined cooling heating and power comprehensive energy system |
| CN111555285B (en) * | 2020-04-03 | 2022-06-17 | 浙江工业大学 | Energy flow decoupling analysis and calculation method for distributed combined cooling heating and power comprehensive energy system |
| CN112751341A (en) * | 2020-12-29 | 2021-05-04 | 天津大学合肥创新发展研究院 | Island hydrogen-containing comprehensive energy system time sequence load flow calculation method considering energy coupling |
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