A Time-Space Decomposition and Coordination Algorithm for AC-DC Interconnected Power Grids

Abstract

The invention discloses an AC / DC interconnected network day-ahead unit commitment method employing time-space decomposition coordination and belongs to the technical field of electric power dispatching automation. The method includes obtaining unit commitment basic data; establishing a unit commitment main model and slave models of a plurality of time periods according to the unit commitment basic data, solving the unit commitment main model by adopting a linear hybrid integer programming algorithm, obtaining the optimal solution of the main model and transmitting to the slave models, and solving the slave models through parallel computing by adopting a non-linear interior point method; if the optimization targets of the slave models are 0, taking the result as the optimal solution of the AC / DC interconnected network day-ahead unit commitment and sending the result to the units as a AC / DC interconnected network day-ahead unit commitment scheduling scheme. The method provided by the invention can be used for optimizing power grids with large amount of high voltage DC power transmission wire access, improves the computation accuracy distinctively, effectively ensures the safety of a power generation and transmission scheme and has important reality significance and a good practical prospect.

Description

technical field [0001] The invention belongs to the technical field of electric power dispatching automation, and in particular provides a time-space decomposition and coordination method for combining AC and DC interconnected power grids. Background technique [0002] In recent years, UHVDC transmission technology has achieved leapfrog development in China, and large-scale AC-DC interconnection grids are playing an important role in cross-regional and cross-provincial resource allocation and renewable energy consumption. With the rapid development of AC-DC interconnected grids, the traditional safety-constrained unit combination plan and DC transmission plan have been difficult to adapt to the needs of future development and are facing huge challenges. [0003] In the AC-DC interconnection grid, since the DC transmission power directly affects the start-stop and power generation plan of the DC sending and receiving end grid units, and the operation mode of the DC system is ...

AI Technical Summary

Problems solved by technology

In order to reduce the scale of the problem and reduce the difficulty of solving the multi-area unit combination, the superior dispatching organization simply considered the DC power flow model. Due to the operating characteristics of the DC system, the result may cause local reactive power shortage and voltage problems. Therefore, the unit combination of the AC-DC interconnected grid must also be compatible with the practical constraints of various DC tie-lines, and realize the coordinated optimization and closed-loop feedback of the DC power plan. further complicating the issue

[0005] The existing safety constrained unit combination (SCUC) problem is generally only based on the DC power flow constraints, optimizing the start-stop and power generation schedule of the units, without considering the node voltage constraints and AC network loss

However, this method does not consider the constraints of DC steady-state operation, and it is difficult to meet the requirements of the current AC-DC interconnected power grid unit combination plan; The gap problem makes it difficult to ensure the optimal solution, and the selection of the iteration step size and iteration direction of the Lagrangian method depends on the rationality of the algorithm design, which is likely to cause iterative oscillations in the calculation process and the calculation time is too long

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