Self-adaptive device and method for analyzing global power flow of generation, transmission and distribution

Abstract

The invention provides a self-adaptive device and a method for analyzing global power flow of generation, transmission and distribution, which belongs to the technical field of power transmission and distribution of power systems. The device comprises an upper computer and a lower computer, wherein the lower computer comprises a power-flow feedback module; a global power system is divided into a master system and a slave system; according to the characteristics of each part of the power system, the master system adopts a Newton-Raphson power-flow analysis method, while the slave system adopts a forward-backward substitution power-flow analysis method; and the master system and the slave system are organically linked together through master-slave-system association nodes in the middle. The invention has the advantages that the device adopts the power-flow feedback module, uses slave-system node-voltage signals obtained from last power-flow calculation of the slave system for next power-flow calculation of the slave system, and realizes the optimization of the prior forward-backward substitution algorithms, and as the method adopts the forward-backward substitution method which reduces iterations compared with the prior forward-backward substitution method, the device for analyzing global power flow not only guarantees accurate power-flow analysis, but also raises convergence rate and saves storage space.

Description

technical field [0001] The invention belongs to the technical field of power transmission and distribution in electric power systems, and in particular relates to an adaptive power transmission and distribution global power flow analysis device and method. Background technique [0002] Power flow analysis is a basic electrical analysis operation for studying the steady-state operation of the power system. It has great practical value in all aspects of the power system. The task of conventional power flow analysis is to determine the operation of the entire system according to the given operating conditions and network structure. Status, such as the voltage on each bus, the power distribution in the network, and power loss. [0003] In most traditional power flow analysis, the analysis of the global power flow generally adopts the unified power flow analysis method, but in fact the characteristics of the power generation and transmission system and the power distribution syst...

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Problems solved by technology

[0004] (1) Differences in network structure: the power distribution system is usually radial, while the transmission system is usually a ring network; there are a large number of generator nodes in the power generation and transmission system, that is, PV nodes, and most of the load nodes in the power distribution system are At the PQ node, the linearity of the power flow equation of the distribution system is higher than that of the power generation and transmission system, which determines that the simple and efficient forward-backward generation is suitable for the power flow analysis of the distribution system, but for the power flow of the power generation and transmission system with high nonlinearity, the forward-pull It is difficult to obtain good convergence performance by the back-substitution rule

[0005] (2) Differences in network parameters: there are many short branches in the power distribution system, and the numerical conditions of the Jacobian matrix of the distribution power flow equation are generally poor; The difference is large, and the numerical condition of the Jacobian matrix is ​​poor, which causes serious numerical problems in the global power flow analysis. Therefore, if the global power flow adopts a unified Newton-like algorithm, the reliability of the analysis cannot be guaranteed, and the r / x is generally large, and the P-Q fast decomposition method cannot be used for global power flow analysis

[0006] (3) The difference in power flow size: the power unit of power generation and transmission power flow is MW, while the power unit of distribution power flow is generally kW. Therefore, the convergence accuracy requirements of power flow and distribution power flow should not be the same. The global power flow can be analyzed based on the base value and convergence accuracy. When the power flow of power generation and transmission converges, the error of the power flow of power distribution is still very large, and it is difficult to meet the requirements of both.

[0014] This effectively solves the problem of power and voltage mismatch to a large extent, but since it is not corrected during the conversion process of the associated node of the master-slave system, that is, the boundary node, this will seriously affect the accuracy of the analysis results, and Due to the large network structure of the global power system for transmission, transmission and distribution, the analysis and calculation are complex, and the calculation amount is even greater when considering reducing the boundary mismatch of the global network. Therefore, it is particularly important to find an analysis method with accurate calculation and fast convergence.

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