CN101141064A - Method for distributed tidal current analyzing by exchange boundary node state and net damage information - Google Patents
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Abstract
The invention discloses a method of completing the distributed tide analysis by exchanging the border node state and the network damage information, which comprises: establishing a distributed tide analyzing system according to the actual scheduling management manner of the electric power system; based on the topology connection relations of the electric power system and the operation situations of the practical system, dividing the interconnected electric network by the dividing method with border area, and clarifying the counting objects and the data sources of the counting server and the coordinating counting server; a domain tide counting server and the superior coordinating counting server are initialized by counting data and parameters, while the coordinating counting server calls the domain tide counting server to together complete the network integrative tide decomposition coordinating solve; besides, the servers call the processes, the domain tide counting server feeds back the result to the coordinating counting server so as to make the coordinating counting server obtain the convergent network integrative tide result.
Description
Technical Field
The invention relates to a method for completing distributed power flow analysis, in particular to a method for completing distributed power flow analysis by exchanging boundary node states and network loss information, and belongs to the technical field of distributed simulation of power systems.
Background
With the continuous strengthening of the interconnection of the power system, the power grid is more complex in structure, and the operation difficulty is greatly increased. When a local fault occurs, if the fault is not handled properly, a serious accident endangering the whole system can be developed. In order to improve the safety and stability of the interconnected power system, it is increasingly necessary to perform non-simplified integrated simulation analysis on the whole power grid.
The power grid of China is coordinately managed and controlled by a multi-level dispatching center, and a management system of 'hierarchical management, hierarchical control and distributed processing' is adopted. As shown in fig. 1, a regional power grid dispatching center with a lower level, such as provincial dispatching and local dispatching, is only responsible for maintaining power balance in the governed region, managing and maintaining system operating states and parameters; the dispatching center with higher level, such as network dispatching and national dispatching, is responsible for inter-regional power exchange control and coordinating regional power grid dispatching activities. Because the power system in China has the characteristics of wide area distribution, massive parameters and complex model, the high-level scheduling center cannot directly acquire the state and parameters of the governed power grid, and the low-level scheduling center needs to forward or report required data layer by layer. Therefore, the time required for acquiring, synchronizing and integrating national power grid parameters and real-time states is long, and the maintenance difficulty is high. Meanwhile, with the continuous deepening of the electric power marketization process, in the market competition, each scheduling mechanism pays more attention to the protection of data and information of the scheduling mechanism, the information barrier of each scheduling mechanism is thickened, and the sharing of the data and the information in the system is further hindered. Therefore, the traditional centralized whole-network integrated simulation calculation is difficult to realize on line.
The power grid analysis and calculation method adopting the distributed calculation technology can obtain the whole-network integrated simulation analysis result while keeping the independence of the data and calculation resources of each party participating in the calculation, and has the characteristics of high speed and efficiency, information safety, flexible application and easy expansion. The distributed load flow calculation has the important function of obtaining a unified simulation result of the whole network while keeping the calculation independence of each scheduling center, so that the technology is expected to become an effective means for solving the integrated simulation of the large-scale interconnected system. At present, the research on the interconnected power grid distributed tide and related fields at home and abroad mainly focuses on the following aspects:
1. a reasonable power network segmentation method;
2. parallel power flow solving is carried out on transplanting and testing in a normal distributed environment;
3. equivalent network calculation and system unbalanced power distribution in the flow decomposition coordination solving process;
it can be seen that research on the existing interconnected power grid integrated power flow decomposition and coordination calculation method mainly focuses on how to perform decomposition of power flow calculation according to the actual power system region condition and on the improvement of the existing parallel power flow algorithm. Most of the researches lack consideration on characteristics of high communication delay, data and computing resource heterogeneity and the like of a distributed computing environment in a wide area network environment, and a decomposition coordination computing model capable of uniformly processing flow balance and unbalanced power distribution of the whole network is not established, so that the application capability in an actual power system is insufficient.
Disclosure of Invention
The invention aims to provide a method for completing distributed power flow analysis by exchanging boundary node states and network loss information, which takes the current of a connecting line as a coordination variable, only needs to transmit a small amount of boundary information in the calculation process and can flexibly deal with the problem of unbalanced power distribution of the whole network.
The invention is realized by adopting the following technical means:
a method for completing distributed power flow analysis by exchanging boundary node state and network loss information comprises the following steps:
the system is defined as (S) 0 ) (ii) a Comprising a two-zone system (S) 1 ) And (S) 2 ) Are connected with each other through a connecting line l; wherein (B) 1 )(B 2 ) Respectively represent (S) 1 )(S 2 ) Boundary node of region (S) ln 1 )(S ln 2 ) Are respectively (S) 1 )(S 2 ) The network is composed of other nodes except the boundary node; border node B 1 And B 2 Splitting respectively, virtualizing boundary nodes
And
and connecting the connecting line l with the virtual boundary nodes at the two ends of the connecting line lAnd
viewed as a singleA S B Then the region plays a role of connecting all other regions and is defined as a boundary region;
the region S 1 And S 2 Belongs to the jurisdiction range of a regional power grid dispatching center, namely a region S B Belonging to the jurisdiction range of a superior dispatching center; under the segmentation mode, the convergence condition of the whole network flow is as follows: region S 1 And S 2 The medium power flow calculation reaches convergence, the internal node power reaches balance, and the boundary node state satisfies
Wherein u is B And theta B Is a boundary node B in the convergence result of the power flow calculation in the regional power grid 1 And B 2 Voltage magnitude and phase angle vector of;
andis a boundary region S B Boundary node B during convergence of internal load flow calculation 1 And B 2 Voltage magnitude and phase angle vector of;
is a boundary node B in the convergence result of regional power grid load flow calculation 1 And B 2 Taking the inflow as the positive direction of a vector formed by injection current phasors from a connecting line;
is a boundary region S B From the boundary node B when the medium power flow calculation is converged 1 And B 2 The vector formed by the current phasors injected into the connecting line takes the outflow direction as the positive direction.
step 3.1: a load flow calculation server in a regional power grid dispatching center initializes network parameters of the governed power grid, wherein the network parameters comprise types, loads and generator output set values of all network nodes participating in load flow calculation, generator end node voltage amplitude values, relaxation node phase angles and the like;
step 3.2: a load flow calculation server in a regional power grid dispatching center initializes boundary condition information, wherein the boundary condition information comprises the number, the name and the like of boundary nodes, and the composition of boundary conditions, namely a vector composed of injection current phasors of the boundary nodes and a regional power grid relaxation node phase angle;
step 3.3: a load flow calculation server in the regional power grid dispatching center initializes load flow calculation parameters, including an iteration solving method, maximum iteration times, upper and lower node voltage limits and minimum power deviation for judging load flow convergence;
step 3.4: a coordination calculation server in the superior dispatching center initializes the network parameters of the boundary area, including the name of the boundary node and the call wire impedance;
step 3.5: a coordination calculation server in a superior dispatching center sets control parameters of the whole-network integrated power flow coordination solution; the maximum iteration times, the proportional coefficient of the total network active network loss borne by each region and the boundary node power balance precision requirement are determined, namely the maximum amplitude of unbalanced current vectors on the boundary nodes required by the boundary node power balance is determined.
And 4, step 4: the coordination calculation server calls a regional power flow calculation server to jointly complete the whole network integrated power flow decomposition coordination solving process; the call flow between servers includes the following basic steps:
step 4.1: a coordination calculation server in the superior dispatching center initializes local basic network data and calculation parameters according to the steps 3.4 and 3.5, and an area load flow calculation server in the area dispatching center initializes the local basic network data and the calculation parameters according to the steps 3.1-3.3;
step 4.2: protocol for making a networkThe dispatching calculation server sets an initial boundary condition, namely a vector I consisting of injection current phasors from a connecting line on a boundary node of a regional power grid B And a vector theta formed by phase angle set values of relaxation nodes of each regional power grid, and sending corresponding injection current and the phase angle set values to a regional power grid load flow calculation server according to the networking division relationship in the step 2;
step 4.3: the regional power grid load flow calculation server starts the regional load flow calculation process, a regional load flow equation is solved according to the obtained boundary conditions and the internal node parameters, and the voltage V of the deviation boundary node is obtained from the converged load flow result B i And regional loss information P loss i I =1,2, and sends the information to the coordination calculation server;
step 4.4: the coordination calculation server calculates the current unbalance amount delta I of the boundary node and the unbalance amount delta P of the whole network active network loss borne by the regional power grid according to the obtained regional power flow calculation result information and parameters set in the initialization process;
step 4.5; if | [ Δ I, Δ P] T ‖ 2 And (5) judging the power flow convergence of the whole network if the value is less than or equal to xi, ending the calculation process, wherein | · | 2 Representing the two norms of the vector, and xi is a small normal number; otherwise according to [ Delta I, delta P] T Calculating a boundary condition correction amount [ Delta I [ ] B ，ΔΘ] T Then updating the boundary condition set value, and returning to the step 4.2;
and 5: and the regional power grid load flow calculation server feeds the calculation result back to the coordination calculation server so that the coordination calculation server obtains a converged whole-network integrated load flow calculation result.
Judging whether the integrated power flow of the whole network is consistent and convergent according to the calculated current unbalance of the boundary nodes and the unbalance of the active network loss of the regional power grid; the following basic conditions need to be satisfied simultaneously:
a: the power of the boundary nodes is balanced, namely, an equation is satisfied;
b: the active network loss of the whole network is reasonably distributed among the regional power networks, the following equations are satisfied,
wherein = { η = [ (+ ]) j Is regional grid S 1 And S 2 The proportion vector which bears the active network loss of the whole network, i =1,2,
P i loss the active network loss is counted from the regional power grid load flow calculation result;
the total network active power loss is obtained by adding the active power loss of each regional power network; delta P loss i The unbalance amount of the whole network active power loss borne by the regional power grid is defined as the unbalance amount of the regional power grid active power loss.
The aforementioned boundary conditions include: vector I consisting of injected current phasors from tie lines on boundary busbars of a regional power grid B And a phase angle set value theta of the relaxation node of the regional power grid.
The regional power flow calculation server calculates regional power flow according to given boundary conditions; wherein said area network S 1 ：
The power grid is composed of n nodes and a plurality of branches, and the load flow calculation model can be expressed in a nonlinear equation set form, namely
Whereini =1, 2.. N is the node voltage phasor, g is the node power balance equation, P i SP And Q i SP Is the given active and reactive power of node i,G ij +jB ij is the admittance between node i and node j, j e i representing all nodes associated with inode, including inode itself.
Foregoing S 1 All nodes in the area are composed of internal nodes S ln 1 And border node B 1 Two parts, respectively
A vector composed of voltage phasors representing the internal node, toA vector representing the composition of boundary node voltage phasors; correspondingly, the node power balance equation set described in equation (2) can be divided into two categories, i.e., the internal node S ln 1 System of power balance equations g ln 1 And the power balance equation set g of the boundary nodes B 1 (ii) a If the boundary node is not selected as a loose node when the regional power grid calculates the load flow, the power balance equation g of the internal node is obtained under the conditions of finishing the active output and the node voltage amplitude of the middle generator node of the given internal node, the active and reactive loads of the load node and the voltage amplitude and the phase angle of the loose node ln 1 Boundary node power balance equation g, related to internal node and boundary node voltages B 1 In relation to the internal node voltage, the boundary node voltage and its injected current phasor from the tie line, it is expressed in the form,
wherein
Is formed by a border node B 1 The vector consisting of the injected current phasors from the tie-line,representing the conjugate of the injected current phasor from the tie-line at node k, with the other variables having the same meaning(3)。
After the basic data initialization process in step 3.1 is completed, I is given B 1 And regional power grid S 1 Internal relaxation node voltage phase angle set value theta ref 1 The equation (4) can be solved by adopting a common Newton-Raphson method to obtain the regional power grid S 1 The tidal current inside.
In the step 4.3, the coordination calculation server needs to calculate the current unbalance amount Δ I of the boundary node and the unbalance amount Δ P of the regional power grid burdening the whole network active power loss according to the boundary condition, the tie line parameter and the regional power grid load flow calculation result, that is, [ Δ I, Δ P [ ]] T . The specific calculation flow is shown in fig. 6, and includes the following steps:
a: coordination calculation server setting boundary condition I B And theta are sent to the regional load flow calculation server;
b: the regional power flow calculation server calculates the regional power grid power flow according to the formula in the step (4), and extracts V from the power flow result B And P loss Information wherein V B Is a vector of boundary node voltage phasors, P loss The regional power grid active power loss information is sent to a coordination calculation server;
c: the coordination calculation server calculates the voltage V according to the boundary node B Calculating the theoretical value of the injection current of the boundary node from the connecting line according to the formula (5)
Taking the outflow boundary node as the positive direction,
a boundary condition current I set in B And injection current theoretical value
The sum is the boundary node current unbalance amount Delta I
d, the coordination calculation server loads the proportion vector n of the whole-network active network loss according to the set regional power grid and the active network loss information P counted in the tidal current results of each regional power grid loss Calculating a vector consisting of the active network loss unbalance amount of the regional power grid according to the formula (2)
The coordination calculation server adopts a modified Jacobian-freeNewton-GMRES (m) method to calculate the correction quantity of the boundary condition and iterates until II [ Delta I, delta P] T ‖ 2 Xi is less than or equal to xi, and the specific steps are as follows:
a. let k = -1, let x B ＝[Re(I B )，Im(I B )，Θ] T Is a vector of boundary conditions in which Re (I) B ) And Im (I) B ) Vectors respectively representing the real part and the imaginary part of the injection current phasor of the boundary node from the connecting line; given an initial boundary condition x B 0 Selecting any non-singular matrix M 0 Is a pre-processing matrix;
k = k +1, repeating steps a-I up to | [ Δ I, Δ P |)] T ‖ 2 Xi is less than or equal to or k is more than maxNIter, and the maxNIter is limited by the Newton iteration times, and the process is finished;
c. order to
As a boundary condition of x B k The boundary node current unbalance and the regional active network loss unbalance obtained through the calculation in the steps a to e are needed to be separated for calculation;
d.
l＝1，ρ＝β＝‖r 0 ‖ 2 ，v 1 ＝r 0 ，errtol G ＝ε‖r 0 ‖‖ 2 ＞0，1＞ε＞0；
e. if ρ > errtol G And l < maxGIter, maxGIter being the GMRES iteration number limit, then l = l +1, z l ＝M k v l ，
v l+1 ＝ΔG l W is a small normal number, typically 10 -5 ＞w＞0；
f. Modifying a pre-processing matrix
g. Orthogonalization of V l+1 ＝[v 1 ，v 2 ，...，v l+1 ]Obtaining a Hessenberg array
Solving a solutionGet ρ and y 1 If ρ < errtol G Then obtain
Otherwise, returning to the step e;
h. 
i. modifying a pre-processing matrix
Returning to the step b;
the foregoing steps f and i are inner and outer layer pre-processing matrix modifications.
Compared with the prior art, the invention has the following obvious advantages and beneficial effects:
the invention discloses a method for completing distributed power flow analysis by exchanging boundary node states and network loss information, which is used for solving the problems of unbalanced power distribution of the whole network by taking the current of a connecting line as a coordination variable and only transmitting a small amount of boundary information in the calculation process aiming at the distributed monitoring technology of a power system in China and the current situation of power grid interconnection.
Drawings
FIG. 1 is a schematic diagram of a prior art multi-level dispatch center connection;
FIG. 2 is a schematic diagram of a basic flow of distributed integrated power flow analysis;
FIG. 3 is a schematic diagram of a distributed power flow analysis system of a power system;
FIG. 4 is a schematic diagram of a systematic segmentation approach with boundary regions;
FIG. 5 is a schematic diagram of a whole-network integrated power flow decomposition coordination solving process;
FIG. 6 is a block diagram of a coordinated computation server computing [ Δ I, Δ P ]] T A process schematic;
FIG. 7 is a schematic diagram of coordination of interconnection of two areas;
FIG. 8 is a schematic diagram of a system segmentation approach with boundary regions;
fig. 9 is a schematic diagram of the division of the IEEE39 system.
Detailed Description
The following description of the embodiments of the present invention is provided with reference to the accompanying drawings:
fig. 2 is a schematic diagram of a basic flow of distributed integrated power flow analysis;
the method is a method for completing the coordination solution of the whole network tidal current by exchanging boundary node states and regional power grid active power network loss information on the premise of keeping the calculation independence of each scheduling center by means of a Jaobian-free Newton GMRES (m) iterative algorithm. The method can complete the whole-network integrated load flow calculation which meets the following basic requirements:
a. all nodes in the whole network meet power balance;
b. the whole-network active network loss is reasonably distributed among all regional power grids, namely the whole-network active network loss is shared by all the regional power grids according to a certain proportion;
c. independent voltage phase angle reference nodes can be adopted in the process of calculating the power flow of each regional power grid;
fig. 3 is a schematic diagram illustrating a connection of a whole network integrated power flow analysis; the tidal current calculation server in the regional dispatching center is responsible for tidal current calculation of a power grid managed by the regional dispatching center; and a coordination calculation server in the upper-level dispatching center is responsible for coordinating the power flow calculation process of each regional power grid, namely, the power flow calculation result of the regional power grid is influenced by changing boundary conditions required by the regional power grid power flow calculation until the power flow calculation of all the regional power grids simultaneously achieves the same power flow result as that of the whole-grid centralized solution convergence.
Please refer to fig. 4, which is a schematic diagram of a system segmentation method with boundary areas;
as can be seen from the figure, the system S 0 Comprising a two-zone system S 1 And S 2 They are connected to each other by a connecting line l. Wherein B is 1 Represents S 1 Boundary node of region, S ln 1 Is S 1 Except for the border nodes. S 2 The situation is similar. If the border node B is 1 And B 2 Split respectively, virtualize out boundary nodes
And
and connecting the connecting line l with the virtual boundary nodes at the two ends of the connecting line l
Andviewed individually as an S B Then a region serves to connect all other regions and may be referred to as a border region. Region S 1 And S 2 Belonging to the jurisdiction of a regional power grid dispatching center, and a region S B Belonging to the jurisdiction of a superior dispatching center. Under the segmentation mode, the convergence condition of the whole network flow is as follows: region S 1 And S 2 The medium power flow calculation reaches convergence, and the internal node power of the medium power flow calculation reaches convergenceAre all balanced and the boundary node state is satisfied
Wherein u is B And theta B Is a boundary node B in the convergence result of the power flow calculation in the regional power grid 1 And B 2 The voltage magnitude and phase angle vector of (a);
and
is a boundary region S B Boundary node B during convergence of internal load flow calculation 1 And B 2 Voltage magnitude and phase angle vector of;
is a boundary node B in the convergence result of regional power grid load flow calculation 1 And B 2 Adding a vector formed by injection current phasors from a connecting line, and taking inflow as a positive direction;
is a boundary region S B From boundary node B when medium load flow calculation is converged 1 And B 2 The vector formed by the current phasors injected into the connecting line takes the outflow direction as the positive direction.
Please refer to fig. 5, which is a schematic diagram of a whole-network integrated power flow decomposition and coordination solving process; as can be seen, the following steps are included;
a. a coordination calculation server in a superior dispatching center initializes local basic network data and calculation parameters according to steps 3.4 and 3.5, and an area load flow calculation server in an area dispatching center initializes the local basic network data and the calculation parameters according to steps 3.1-3.3;
b. the coordination calculation server sets an initial boundary condition, namely a vector I consisting of injection current phasors from a tie line on a boundary node of a regional power grid B And a vector theta consisting of phase angle set values of relaxation nodes of each regional power grid, and sending (network communication) corresponding injected current and the phase angle set values to a regional power grid load flow calculation server according to the networked division relationship in the step 2;
c. the regional power grid load flow calculation server starts the regional load flow calculation process, a regional load flow equation is solved according to the obtained boundary conditions and the internal node parameters, and the voltage V of the deviation boundary node is obtained from the converged load flow result B i And regional loss information P loss i I =1,2 and sends (network communication) this information to the coordinating computing server;
d. the coordination calculation server calculates the current unbalance amount delta I of the boundary node and the unbalance amount delta P of the active network loss of the whole regional power grid burden according to the obtained regional power flow calculation result information and the parameters set in the initialization process;
e. if | [ Δ I, Δ P] T ‖ 2 And (5) judging the power flow convergence of the whole network if the value is less than or equal to xi, ending the calculation process, wherein | · | 2 Representing the two-norm of the vector, ξ is a small normal number; otherwise according to [ Delta I, delta P] T Calculating a boundary condition correction amount [ Delta I [ ] B ，ΔΘ] T And (4) updating the set value of the boundary condition and returning to the step (4.2).
Referring to FIG. 6, a calculation of [ Δ I, Δ P ] for the coordination calculation server is shown] T A process schematic;
a. coordination calculation server setting boundary condition I B And theta are sent to the regional load flow calculation server;
b. the regional power flow calculation server calculates the regional power grid power flow according to the steps of 4.3.1-4.3.3, and V is extracted from the power flow result B And P loss Information wherein V B Is a vector of boundary node voltage phasors, P loss The regional power grid active power grid loss information is sent to a coordination calculation server;
c. the coordination calculation server calculates the voltage V according to the boundary node B Calculating boundary nodes from the junctor according to the equation (5)Theoretical value of injection current
Taking the outflow boundary node as the positive direction,
wherein the boundary condition current I set in the above-mentioned a B And injection current theoretical value
The sum is the boundary node current imbalance Δ I, i.e.
d. The coordination calculation server is used for calculating active network loss information P counted in the tidal current results of each regional power grid according to the set proportion vector II of the total active network loss borne by the regional power grid loss Calculating a vector consisting of the active network loss unbalance amount of the regional power grid according to the formula (2)
In a specific embodiment, the invention is carried out according to the following 3 stages
1. Stage 1: and starting from the topological connection relation of the power system, and segmenting the system by adopting a segmentation method with a boundary region according to the running condition of the actual system.
The power system has the characteristics of regional operation and distributed management, the coupling between regional power grids is weak, and a general interconnected power grid can be simplified into a two-regional interconnected system form through a few connecting lines. As shown in FIG. 7, the system S 0 Comprising a two-zone system S 1 And S 2 They are connected to each other by a connecting line l. Wherein B is 1 Represents S 1 Boundary node of region, S ln 1 Is S 1 Except for the border nodes. S. the 2 The situation is similar. If the border node B is 1 And B 2 Split respectively, virtualize out boundary nodesAndand connecting the connecting line l with the virtual boundary nodes at the two ends of the connecting line l
Andviewed individually as an S B Then a region serves to connect all other regions and may be referred to as a border region. Region S 1 And S 2 Belonging to the jurisdiction of regional power grid dispatching center, and a region S B Belonging to the jurisdiction of a superior dispatching center.
FIG. 8 is a schematic diagram of a system partition method with boundary areas;
fig. 9 is a schematic diagram of division of the IEEE39 system.
Taking IEEE39 node system as an example, it is divided into three areas, namely a grid area and a boundary area, and the specific division mode is shown in fig. 4. The branches 9-8, 3-4, 14-15 and 16-17 are connecting lines, the nodes 3, 4, 8, 9, 14, 15, 16 and 17 are boundary nodes, and they share a boundary region; the condition that three regional power grid regions contain the number of nodes is shown in table 1, and the node and branch parameters of each region are shown in tables 2-7
TABLE 1IEEE39 node system area situation
| Region(s) | 1 | 2 | 3 |
| Number of |
15 | 12 | 12 |
TABLE 2 regional grid regional 1 node parameters
| Node point Number (C) | Voltage of Amplitude value | Voltage of Phase angle | Active power Output force | Reactive power Output force | Active power Load(s) | Reactive power Load(s) | In parallel Electrical conductance | In parallel connection Sodium battery | Node point Types of |
| 1 | 1 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | |
| 2 | 1 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | |
| 3 | 1 | 0 | 0 | 0 | 3.22 | 0.024 | 0 | 0.1107 | |
| 9 | 1 | 0 | 0 | 0 | 0 | 0 | 0 | 0.1902 | PQ |
| 17 | 1 | 0 | 0 | 0 | 0 | 0 | 0 | 0.0671 | PQ |
| 18 | 1 | 0 | 0 | 0 | 1.58 | 0.3 | 0 | 0 | |
| 25 | 1 | 0 | 0 | 0 | 2.24 | 0.472 | 0 | 0 | |
| 26 | 1 | 0 | 0 | 0 | 1.39 | 0.17 | 0 | 0 | |
| 27 | 1 | 0 | 0 | 0 | 2.81 | 0.755 | 0 | 0 | |
| 28 | 1 | 0 | 0 | 0 | 2.06 | 0.276 | 0 | 0 | PQ |
| 29 | 1 | 0 | 0 | 0 | 2.835 | 0.269 | 0 | 0 | |
| 30 | 1.047 | 0 | 2.5 | 0 | 0 | 0 | 0 | 0 | |
| 37 | 1.027 | 0 | 5.4 | 0 | 0 | 0 | 0 | 0 | PV |
| 38 | 1.026 | 0 | 8.3 | 0 | 0 | 0 | 0 | 0 | |
| 39 | 1.03 | 0 | 10 | 0 | 11.04 | 2.5 | 0 | 0 | Vθ |
TABLE 3 regional grid region 1 Branch parameters
| Head node | Tail node | Resistance (RC) | Reactance | Charging | Transformation ratio | |
| 2 | 1 | 0.0035 | 0.0411 | 0.6987 | 1 | |
| 39 | 1 | 0.001 | 0.025 | 0.75 | 1 | |
| 3 | 2 | 0.0013 | 0.0151 | 0.2572 | 1 | |
| 25 | 2 | 0.007 | 0.0086 | 0.146 | 1 | |
| 18 | 3 | 0.0011 | 0.0133 | 0.2138 | 1 | |
| 39 | 9 | 0.001 | 0.025 | 1.2 | 1 | |
| 18 | 17 | 0.0007 | 0.0082 | 0.1319 | 1 | |
| 27 | 17 | 0.0013 | 0.0173 | 0.3216 | 1 | |
| 26 | 25 | 0.0032 | 0.0323 | 0.513 | 1 | |
| 27 | 26 | 0.0014 | 0.0147 | 0.2396 | 1 | |
| 28 | 26 | 0.0043 | 0.0474 | 0.7802 | 1 | |
| 29 | 26 | 0.0057 | 0.0625 | 1.029 | 1 | |
| 29 | 28 | 0.0014 | 0.0151 | 0.249 | 1 | |
| 2 | 30 | 0 | 0.0181 | 0 | 1.025 |
| 25 | 37 | 0.0006 | 0.0232 | 0 | 1.025 |
| 29 | 38 | 0.0008 | 0.0156 | 0 | 1.025 |
TABLE 4 regional grid regional 2 node parameters
| Node point Number (C) | Voltage of Amplitude value | Voltage of Phase angle | Active power Output force | Reactive power Output force | Active power Load(s) | Reactive power Load(s) | In parallel Conductance of electricity | In parallel Sodium battery | Node point Type (B) |
| 4 | 1 | 0 | 0 | 0 | 5 | 1.84 | 0 | 0.1107 | PQ |
| 5 | 1 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | PQ |
| 6 | 1 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | |
| 7 | 1 | 0 | 0 | 0 | 2.338 | 0.84 | 0 | 0 | |
| 8 | 1 | 0 | 0 | 0 | 5.22 | 1.76 | 0 | 0.1902 | PQ |
| 10 | 1 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | |
| 11 | 1 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | PQ |
| 12 | 1 | 0 | 0 | 0 | 0.085 | 0.88 | 0 | 0 | PQ |
| 13 | 1 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | |
| 14 | 1 | 0 | 0 | 0 | 0 | 0 | 0 | 0.183 | |
| 31 | 0.982 | 0 | 5.72 | 0 | 0.092 | 0.046 | 0 | 0 | Vθ |
| 32 | 0.983 | 0 | 6.5 | 0 | 0 | 0 | 0 | 0 | PV |
TABLE 5 regional grid region 2 Branch parameters
| Head node | Tail node | Resistance (RC) | Reactance | Charging capacitor | Transformation ratio |
| 5 | 4 | 0.0008 | 0.0128 | 0.1342 | 1 |
| 14 | 4 | 0.0008 | 0.0129 | 0.1382 | 1 |
| 6 | 5 | 0.0002 | 0.0026 | 0.0434 | 1 |
| 8 | 5 | 0.0008 | 0.0112 | 0.1476 | 1 |
| 7 | 6 | 0.0006 | 0.0092 | 0.113 | 1 |
| 11 | 6 | 0.0007 | 0.0082 | 0.1389 | 1 |
| 8 | 7 | 0.0004 | 0.0046 | 0.078 | 1 |
| 11 | 10 | 0.0004 | 0.0043 | 0.0729 | 1 |
| 13 | 10 | 0.0004 | 0.0043 | 0.0729 | 1 |
| 14 | 13 | 0.0009 | 0.0101 | 0.1723 | 1 |
| 6 | 31 | 0 | 0.025 | 0 | 1.07 |
| 12 | 11 | 0.0016 | 0.0435 | 0 | 1.006 |
| 12 | 13 | 0.0016 | 0.0435 | 0 | 1.006 |
| 10 | 32 | 0 | 0.02 | 0 | 1.07 |
TABLE 6 regional grid regional 3 node parameters
| Node point Number (C) | Voltage of Amplitude value | Voltage of Phase angle | Active power Output force | Reactive power Output force | Active power Load(s) | Reactive power Load(s) | In parallel connection Electrical conductance | In parallel connection Sodium battery | Node point Type (B) |
| 15 | 1 | 0 | 0 | 0 | 3.2 | 1.53 | 0 | 0.183 | |
| 16 | 1 | 0 | 0 | 0 | 3.29 | 0.323 | 0 | 0.0671 | |
| 19 | 1 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | |
| 20 | 1 | 0 | 0 | 0 | 6.8 | 1.03 | 0 | 0 | PQ |
| 21 | 1 | 0 | 0 | 0 | 2.74 | 1.15 | 0 | 0 | PQ |
| 22 | 1 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | |
| 23 | 1 | 0 | 0 | 0 | 2.475 | 0.846 | 0 | 0 | PQ |
| 24 | 1 | 0 | 0 | 0 | 3.086 | -0.922 | 0 | 0 | |
| 33 | 0.997 | 0 | 6.32 | 0 | 0 | 0 | 0 | 0 | PV |
| 34 | 1.012 | 0 | 5.08 | 0 | 0 | 0 | 0 | 0 | |
| 35 | 1.049 | 0 | 6.5 | 0 | 0 | 0 | 0 | 0 | Vθ |
| 36 | 1.063 | 0 | 5.6 | 0 | 0 | 0 | 0 | 0 | PV |
TABLE 7 regional grid region 3 Branch parameters
| Head node | Tail node | Resistance (RC) | Reactance | Charging | Transformation ratio | |
| 16 | 15 | 0.0009 | 0.0094 | 0.171 | 1 | |
| 19 | 16 | 0.0016 | 0.0195 | 0.304 | 1 | |
| 21 | 16 | 0.0008 | 0.0135 | 0.2548 | 1 | |
| 24 | 16 | 0.0003 | 0.0059 | 0.068 | 1 | |
| 19 | 20 | 0.0007 | 0.0138 | 0 | 1.06 | |
| 22 | 21 | 0.0008 | 0.014 | 0.2565 | 1 | |
| 23 | 22 | 0.0006 | 0.0096 | 0.1846 | 1 | |
| 24 | 23 | 0.0022 | 0.035 | 0.361 | 1 | |
| 19 | 33 | 0.0007 | 0.0142 | 0 | 1.07 | |
| 20 | 34 | 0.0009 | 0.018 | 0 | 1.009 | |
| 22 | 35 | 0 | 0.0143 | 0 | 1.025 | |
| 23 | 36 | 0.0005 | 0.0272 | 0 | 1 |
Based on the segmentation mode of the interconnected power system, the regional power grid load flow calculation server is responsible for calculating regional power grid load flow, the coordination calculation server in the superior dispatching center is responsible for updating and sending boundary conditions to each regional power grid, and judging whether the whole network integrated load flow is converged or not.
2. And (2) stage: and performing whole-network integrated power flow decomposition, coordination and calculation initialization. The process includes two parts, namely initialization of a regional power grid load flow calculation server and initialization of a coordination calculation server in a superior dispatching center, which are respectively introduced below.
(2.1) the regional power grid load flow calculation server completes initialization according to the following steps;
(2.1.1) reading in the node and branch parameters of the local region load flow calculation, such as the parameters shown in tables 2 and 3;
(2.1.2) initializing boundary condition information, including boundary node numbers and names, corresponding relations between boundary conditions and boundary nodes and the like;
(2.1.3) initializing load flow calculation control parameters, including a used iteration solving method, maximum iteration times, upper and lower limits of node voltage, convergence criterion and the like;
(2.2) the coordination calculation server in the superior dispatching center completes initialization according to the following steps;
(2.2.1) reading in boundary area network parameters including boundary node names, junctor impedances and the like;
(2.2.2) initializing a regional power grid to bear the whole-grid active power grid loss proportion parameter II;
and (2.2.3) setting control parameters for solving the boundary coordination equation by adopting JFNG (m), wherein the control parameters comprise the maximum Newton iteration times max NIter, the maximum GMRES iteration times maxGIter, the Newton iteration convergence precision ξ (the precision requirement of boundary node current balance and area burden whole network active network loss balance), the GMRES iteration convergence precision epsilon, the finite difference step length w and the like.
3. And (3) stage: and solving the boundary coordination equation by adopting an improved JFNG (m) method to realize the integrated solution of the whole network tide.
The specific solving process is as follows:
(3.1) let k = -1, let x B ＝[Re(I B )，Im(I B )，Θ] T Is a vector of boundary conditions in which Re (I) B ) And Im (I) B ) Respectively representing vectors formed by the real part and the imaginary part of the injection current phasor of the boundary node from the connecting line; given an initial boundary condition x B 0 Selecting any non-singular matrix M 0 As a pre-processing matrix, such as a unit matrix;
(3.2) k = k +1, repeating steps (3.2) to (3.9),
or k > maxNiter, end;
(3.3) entering GMRES (m) to iteratively solve a correction equation:
wherein G' (x) B k ) Represents the boundary coordination equation at x B k The first order inverse of (c), i.e. the Jacobian matrix of the boundary coordination equation, G (x) B k ) As a boundary condition of x B k The value of the time-boundary coordination function, the real and imaginary parts of Δ I need to be separated for calculation, order
(3.4)
l＝1，ρ＝β＝‖r 0 ‖ 2 ，v 1 ＝r 0 ，errtol G ＝ε‖r 0 ‖ 2 ＞0，1＞ε＞0；
(3.5) if ρ > errtol G And l < maxGIter, then l = l +1, calculate z l ＝M k v l ， 
v l+1 ＝ΔG l W is a small normal number, typically 10 -5 ＞w＞0；
(3.6) modifying the preprocessing matrix
(3.7) orthogonalization of V l+1 ＝[v 1 ，v 2 ，...，v l+1 ]Obtaining a Hessenberg array
Solving for
Get ρ and y l If ρ < errtol G Then obtain
Otherwise, returning to the step (3.5);
(3.8)
(3.9) modifying the preprocessing matrix
Returning to the step (3.2);
wherein the boundary coordination function G (x) B ) The evaluation process of (2) is completed according to the following steps:
(3.10) the coordination calculation server in the upper-level dispatching center sets boundary conditions, namely a vector I consisting of injection current phasors from the connecting lines on the boundary nodes of the regional power grid B And a vector theta formed by phase angle set values of relaxation nodes of each regional power grid, and sending corresponding injection current and the phase angle set values to a regional power grid load flow calculation server according to the region membership;
(3.11) regional grid load flow calculationThe server starts the load flow calculation process of the region, and solves S according to the obtained boundary conditions and the internal node parameters 1 And S 2 Power flow equation (4) to derive the voltage V of the deviated boundary node from the converged power flow result B And regional loss information P loss And sends the information to the coordination calculation server;
(3.12) the coordination calculation server calculates the current unbalance amount delta I of the boundary node according to the obtained regional power flow calculation result information and the parameters set in the initialization process according to the formulas (5) and (6), and according to the formulas
(2) Calculating the unbalance delta P of the total network active network loss borne by the regional power grid;
the computer simulation results for the present invention are as follows:
the simulation was performed using an IEEE39 node system. The network parameters and the area conditions are shown in tables 1 to 7. The calculation was carried out under the following conditions:
(1) The parameters of the power flow calculation server of each region are as follows:
(1.1) starting power flow of each regional power grid from flat start, namely, the voltage amplitude and the phase angle of a PQ node are respectively 1 and 0, the voltage phase angle of a PV node is set to be 0, and the phase angle of a relaxation (V theta) node is 0;
(1.2) solving a power flow equation (3) by adopting a Newton-Raphson iteration method;
(1.3) the maximum iteration number is 30, the upper limit and the lower limit of the node voltage amplitude are 1.5 and 0.5, and the power flow convergence precision is 10 -7 ；
(2) The coordination side calculates the server parameters as follows:
(2.1) setting a proportion vector of the regional power grid burdening the active power grid loss of the whole grid as = [0,1,0], namely, setting all the grid losses of the whole grid to be borne by loose nodes in the regional power grid region 2, wherein the setting is consistent with the setting of IEEE39 node standard data;
the control parameter of the (2.2) JFNG (m) algorithm is ξ =10 -4 ，ε＝0.1，max NIter＝30，maxGlter＝30， w＝10 -6 。
And performing integrated power flow decomposition coordination calculation on the IEEE39 node system according to the conditions.
Table 8 distributed load flow calculation test results
| System for controlling a power supply | Concentrated NR method Number of iterations | Improved JFNG (m) method | Node voltage amplitude Maximum deviation of value | Nodal voltage phase Maximum deviation of angle | ||
| Newton Iteration | GMRES Iteration | Evaluation Number of times | ||||
| IEEE39 | 3 | 4 | 0+7+4+4 | 19 | 6.37×10 -7 | 3.94×10 -6 |
As can be seen from table 8: the JFNG (m) algorithm is adopted to solve the boundary coordination equation, the outer layer iteration times of the boundary coordination equation are equivalent to those of the traditional serial NR method, and the boundary coordination equation has high convergence. The self-adaptive preprocessing technology can obviously improve the convergence of inner layer iteration, thereby reducing the times of solving the coordination equation, greatly improving the communication times of the algorithm in a distributed computing environment, and enabling the algorithm to be suitable for a high-delay wide area network communication environment. The whole-network integrated power flow decomposition coordination solving algorithm provided by the invention has higher calculation precision and can meet the practical calculation requirement.
Finally, it should be noted that: the above embodiments are only used to illustrate the present invention and not to limit the technical solutions described in the present invention; thus, while the invention has been described in detail with reference to the various embodiments thereof, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted; all such modifications and variations are intended to be included herein within the scope of this disclosure and the appended claims.
Claims (9)
1. A method for completing distributed power flow analysis by exchanging boundary node state and network loss information is characterized by comprising the following steps:
step 1; constructing a distributed power flow analysis system according to an actual scheduling management mode of the power system;
the electric power system is coordinated and consistent by a regional dispatching center and a superior dispatching center, and information is interconnected;
the distributed load flow calculation system is formed by connecting a load flow calculation server in a regional dispatching center and a coordination calculation server in a superior dispatching center through a network; wherein: the load flow calculation server is responsible for load flow calculation of the power grid managed by the load flow calculation server; a coordination calculation server in the upper-level dispatching center is responsible for coordinating the power flow calculation process of each regional power grid;
step 2; starting from the topological connection relation of the power system, segmenting the system by adopting a segmentation method with a boundary region according to the running condition of the actual system, and dividing the interconnected power grid according to the actual network connection condition to determine the calculation objects and data sources of a load flow calculation server and a coordination calculation server;
the system is defined as (S) 0 ) (ii) a Comprising a two-zone system (S) 1 ) And (S) 2 ) Are connected with each other through a connecting line l; wherein (B) 1 )(B 2 ) Respectively represent (S) 1 )(S 2 ) Boundary node of region (S) ln 1 )(S ln 2 ) Are respectively (S) 1 )(S 2 ) A network consisting of other nodes except the boundary node;
border node B 1 And B 2 Splitting respectively, virtualizing boundary nodes
Andand connecting the connecting line l with the virtual boundary nodes at the two ends of the connecting line l
Andviewed individually as an S B Then the region plays a role of connecting all other regions and is defined as a boundary region;
the region S 1 And S 2 Belongs to the jurisdiction range of a regional power grid dispatching center, namely a region S B Belongs to a superior dispatching center tubeScope of jurisdiction; under the segmentation mode, the convergence condition of the whole network flow is as follows: region S 1 And S 2 The medium power flow calculation reaches convergence, the internal node power reaches balance, and the boundary node state satisfies
Wherein u is B And theta B Is a boundary node B in the convergence result of the power flow calculation in the regional power grid 1 And B 2 Voltage magnitude and phase angle vector of;
and
is a boundary region S B Boundary node B during convergence of internal load flow calculation 1 And B 2 The voltage magnitude and phase angle vector of (a);
is a boundary node B in the convergence result of regional power grid load flow calculation 1 And B 2 Adding a vector formed by injection current phasors from a connecting line, and taking inflow as a positive direction;
is a boundary region S B From the boundary node B when the medium power flow calculation is converged 1 And B 2 The vector formed by the current phasors injected into the connecting line takes the outflow direction as the positive direction.
Step 3; the method for initializing the data and parameters for the calculation of the regional load flow calculation server and the superior coordination calculation server comprises the following steps of:
step 3.1: a load flow calculation server in a regional power grid dispatching center initializes network parameters of the governed power grid, wherein the network parameters comprise types, loads and generator output set values of all network nodes participating in load flow calculation, generator end node voltage amplitude values, relaxation node phase angles and the like;
step 3.2: a load flow calculation server in the regional power grid dispatching center initializes boundary condition information, wherein the boundary condition information comprises the number, the name and the like of boundary nodes and the composition of boundary conditions, namely a vector composed of injection current phasors of the boundary nodes and a regional power grid relaxation node phase angle;
step 3.3: a load flow calculation server in the regional power grid dispatching center initializes load flow calculation parameters including a used iteration solving method, maximum iteration times, upper and lower limits of node voltage and minimum power deviation for judging load flow convergence;
step 3.4: a coordination calculation server in the superior dispatching center initializes the network parameters of the boundary area, including the name of the boundary node and the call wire impedance;
step 3.5: a coordination calculation server in a superior dispatching center sets control parameters of the whole-network integrated power flow coordination solution; the maximum iteration times, the proportional coefficient of the whole network active power loss borne by each region and the boundary node power balance precision requirement are determined, namely the maximum amplitude of unbalanced current vectors on the boundary nodes required by the boundary node power balance is determined.
And 4, step 4: the coordination calculation server calls a regional power flow calculation server to jointly complete the whole network integrated power flow decomposition coordination solving process; the inter-server call flow comprises the following basic steps:
step 4.1: a coordination calculation server in the superior dispatching center initializes local basic network data and calculation parameters according to the steps 3.4 and 3.5, and an area load flow calculation server in the area dispatching center initializes the local basic network data and the calculation parameters according to the steps 3.1-3.3;
and 4.2: the coordination calculation server sets an initial boundary condition, namely a vector I consisting of injection current phasors from a connecting line on a boundary node of a regional power grid B And a vector theta consisting of phase angle set values of relaxation nodes of each regional power grid, and according to the networking division relationship in the step 2,sending the corresponding injected current and the phase angle set value to a regional power grid load flow calculation server;
step 4.3: the regional power grid load flow calculation server starts the regional load flow calculation process, a regional load flow equation is solved according to the obtained boundary conditions and the internal node parameters, and the voltage V of the deviation boundary node is obtained from the converged load flow result B i And regional loss information P loss i I =1,2, and sends the information to the coordination calculation server;
step 4.4: and the coordination calculation server calculates the current unbalance amount delta I of the boundary node and the unbalance amount delta P of the active network loss of the whole regional power grid according to the obtained regional power flow calculation result information and the parameters set in the initialization process:
step 4.5: if | [ Δ I, Δ P] T ‖ 2 Judging the power flow convergence of the whole network if the xi is not more than xi, and finishing the calculation process, wherein |. | 2 Representing the two-norm of the vector, ξ is a small normal number; otherwise according to [ Delta I, delta P] T Calculating a boundary condition correction amount [ Delta I [ ] B ，ΔΘ] T Then updating the boundary condition set value, and returning to the step 4.2;
and 5: and the regional power grid load flow calculation server feeds the calculation result back to the coordination calculation server so that the coordination calculation server obtains a converged whole-network integrated load flow calculation result.
2. The method of completing distributed power flow analysis by exchanging boundary node status and network loss information of claim 1, wherein: judging whether the integrated power flow of the whole network is consistent and convergent or not according to the calculated current unbalance of the boundary nodes and the unbalance of the active network loss of the regional power grid; the following basic conditions need to be satisfied simultaneously:
a: the power of the boundary nodes is balanced, namely, an equation is satisfied;
b: the active network loss of the whole network is reasonably distributed among the regional power networks, the following equations are satisfied,
wherein pi = { eta i Is regional grid S 1 And S 2 The proportion vector which bears the active network loss of the whole network, i =1,2,
P i loss the active network loss is counted from the regional power grid load flow calculation result;the total network active power loss is obtained by adding the active power loss of each regional power network; delta P loss i The unbalance amount of the whole network active power loss borne by the regional power grid is defined as the unbalance amount of the regional power grid active power loss.
3. The method of performing distributed power flow analysis by exchanging boundary node state and network loss information of claim 1, wherein: the boundary conditions include: vector I consisting of injected current phasors from tie lines on boundary busbars of a regional power grid B And a phase angle set value theta of the relaxation node of the regional power grid.
4. The method of performing distributed power flow analysis by exchanging boundary node state and network loss information of claim 1, wherein: the regional power flow calculation server calculates regional power flow according to given boundary conditions; wherein said regional power grid S 1 ：
The power grid is composed of n nodes and a plurality of branches, and the load flow calculation model can be expressed in a nonlinear equation set form, namely
Wherein
i =1,2, \ 8230, n is the node voltage phasor, g is the node power balance equation, P i SP And Q i SP Is given active and reactive power, G, of node i ij +jB ij Is the admittance between node i and node j, j e i representing all nodes associated with inode, including inode itself.
5. The method of performing distributed power flow analysis by exchanging boundary node state and network loss information of claim 1, wherein: s 1 All nodes of the area are composed of internal nodes S ln 1 And border node B 1 Two parts, respectively
A vector of voltage phasors representing the internal node, toA vector representing the composition of boundary node voltage phasors; correspondingly, the node power balance equation set described in equation (2) can also be divided into two categories, i.e.Partial node S ln 1 Power balance equation set g ln 1 And power balance equation set g of boundary nodes B 1 (ii) a If the boundary node is not selected as a loose node when the regional power grid calculates the load flow, the power balance equation g of the internal node is obtained under the conditions of finishing the active output of the middle generator node of the given internal node, the voltage amplitude of the node, the active and reactive loads of the load node and the voltage amplitude and phase angle of the loose node ln 1 Internal node and boundary node voltage correlation, boundary node power balance equation g B 1 In relation to the internal node voltage, the boundary node voltage and its injected current phasor from the link line, it is expressed in the form,
wherein
Is formed by a border node B 1 The vector consisting of the injected current phasors from the tie-line,
represents the conjugate of the injected current phasor from the tie line at node k, and the other variables have the same meaning as equation (3).
6. The method of performing distributed power flow analysis by exchanging boundary node state and network loss information of claim 1, wherein: when the basic data initialization process in step 3.1 is completed, I is given B 1 And regional power grid S 1 Internal relaxation node voltage phase angle set value theta ref 1 The equation (4) can be solved by adopting a common Newton-Raphson method to obtain the regional power grid S 1 The tidal current inside.
7. The method of performing distributed power flow analysis by exchanging boundary node state and network loss information of claim 1, wherein: 4.3, the coordination calculation server calculates the current unbalance amount delta I of the boundary node and the unbalance amount delta P of the whole network active power loss borne by the regional power grid according to the boundary condition, the tie line parameter and the regional power grid load flow calculation result; the method comprises the following steps:
a: coordination calculation server setting boundary condition I B And theta are sent to the regional load flow calculation server;
b: the regional power flow calculation server calculates the regional power grid power flow according to the formula (4), and V is extracted from the power flow result B And P loss . Information wherein V B Is a vector of boundary node voltage phasors, P loss The regional power grid active power grid loss information is sent to a coordination calculation server;
c: coordinating and calculating the voltage V of the server according to the boundary node B Calculating the theoretical value of the injection current of the boundary node from the connecting line according to the formula (5)
Taking the outflow boundary node as the positive direction,
a boundary condition current I set in B And injection current theoretical value
The sum is the boundary node current unbalance amount Delta I
d, the coordination calculation server loads the proportion vector n of the whole-network active network loss according to the set regional power grid and the active network loss information P counted in the tidal current results of each regional power grid loss Calculating a vector consisting of the active network loss unbalance amount of the regional power grid according to the formula (2)
8. The method of performing distributed power flow analysis by exchanging boundary node state and network loss information of claim 1, wherein: the coordination calculation server adopts a modified Jacobian-freeNewton-GMRES (m) method to calculate the correction quantity of the boundary condition and iterates until | [ delta I, delta P |)] T ‖ 2 Xi is less than or equal to xi, and the specific steps are as follows:
a. let k = -1, let x B ＝[Re(I B )，Im(I B )，Θ] T Is a vector of boundary conditions in which Re (I) B ) And Im (I) B ) Vectors representing the real and imaginary components of the injected current phasor from the link at the boundary node respectively(ii) a Given an initial boundary condition x B 0 Selecting any non-singular matrix M 0 Is a pre-processing matrix;
k = k +1, repeating steps a-I up to | [ Δ I, Δ P |)] T ‖ 2 Xi is less than or equal to or k is more than maxNIter which is the limit of Newton iteration times, and then the process is finished;
c. order to
As a boundary condition of x B k The boundary node current unbalance and the regional active network loss unbalance obtained through the calculation in the steps a to e are needed to be separated for calculation;
d.
l＝1，ρ＝β＝‖r 0 ‖ 2 ，v 1 ＝r 0 ，errtol G ＝ε‖r 0 ‖ 2 ＞0，1＞ε＞0；
e. if ρ > errtol G And l < maxGIter, maxGIter being the GMRES iteration number limit, then l = l +1, z l ＝M k v l ，
v l+1 ＝ΔG l W is a small normal number, typically 10 -5 ＞w＞0；
f. Modifying a pre-processing matrix
g. Orthogonalization of V l+1 ＝[v 1 ，v 2 ，L，v l+1 ]Obtaining a Hessenberg array
Solving forTo obtain rho and y l If ρ < errtol G Then obtain
Otherwise, returning to the step e;
h.
i. modifying a pre-processing matrix
Returning to the step b;
9. the method of completing distributed power flow analysis by exchanging boundary node status and network loss information of claim 8, wherein: wherein the steps f and i are inner and outer layer preprocessing matrix correction.
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