Multifunctional grid-connected parallel inverter group intelligent control method used in microgrid

Abstract

The invention relates to microgrid and power quality management and aims to provide a multifunctional grid-connected parallel inverter group intelligent control method used in a microgrid. According to the control method, aiming at selected harmonics and reactive current at PCC of a grid-connected point of the microgrid, a multifunctional inverter group intelligent control strategy is adopted; a full-distributed hierarchical control scheme based on a finite time consistency algorithm is adopted for compensation; and all distributed power supplies share compensation capacity according to respective surplus capacity proportions. On the condition of no increase of extra power quality control equipment of the microgrid, the control method disclosed by the invention overcomes the defect that a single inverter has surplus capacity deficiency in term of compensation of harmonics and reactive current; the function that a multifunctional inverter group shares compensation capacity according to surplus capacity proportions can be achieved without use of a central controller. With adoption of the control method, the investment and operation maintenance cost of the microgrid can be reduced, the power quality of the microgrid can be improved and high flexibility can be achieved.

Description

technical field [0001] The invention relates to a multifunctional inverter group control method imitating the intelligence of biological groups, which uses the communication between the grid-connected inverter and the adjacent inverters and the finite time consistency algorithm to realize the specified subharmonic at the PCC of the grid-connected point of the micro-grid A fully distributed hierarchical control method for wave and reactive current compensation, belonging to the fields of electrical engineering, distributed generation, microgrid and power quality management. Background technique [0002] As an important carrier for grid-connected renewable energy, microgrids, on the one hand, realize the integration of highly random new energy into the grid, and on the other hand, provide support for the stability of the grid, and have received extensive attention in recent years. However, with the application of more and more power electronic devices in the microgrid and the ...

AI Technical Summary

Problems solved by technology

Centralized control has the advantages of precise power distribution and no large output power deviation between inverters, but it has certain defects in "plug and play", "N+1" redundancy, etc., and the centralized controller High requirements on the central controller and poor reliability

In contrast, the control strategy without interconnection has flexible features such as "online hot swapping", but in the case of no interconnection, the power distribution between the inverters cannot achieve very accurate results, and it is likely to occur Some inverters work at full load all the time while others work at light load

Based on the above reasons, it is necessary to find a distributed multi-inverter group control strategy, which avoids the disadvantages of low reliability of centralized control, and at the same time realizes hierarchical control suitable for distributed power.

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