Micro-power-grid stabilization control method based on adaptive sliding mode control

Abstract

The invention discloses a micro-power-grid stabilization control method based on adaptive global sliding mode control. The method comprises the following steps of (1) aiming at operation characteristics of grid-connected operation and island operation of a micro power grid, establishing a mathematic mode of an inverter system respectively; (2) combining adaptive control and sliding mode control and constructing adaptive sliding mode control models of the inverter system during the grid-connected operation and the island operation respectively; (3) acting the adaptive sliding mode control models of the inverter system on pulse width modulation PWM, and controlling a three-phase inverter so as to realize three-phase-inverter adaptive sliding mode control of micro-power-grid stabilization. By using the micro-power-grid stabilization control method based on the adaptive global sliding mode control, stability of the micro power grid under different operation modes can be guaranteed; during micro-power-grid grid-connected operation, a micro power grid and main power grid exchange power fluctuation can be effectively restrained so that micro power grid and main power grid exchange power is controllable; and seamless switching of the micro power grid between 2 kinds of operation modes can be realized.

Description

technical field [0001] The invention belongs to the technical field of smart grids, in particular to a three-phase inverter self-adaptive sliding mode control method for realizing the stability of micro grids. Background technique [0002] Distributed generation (distributed generation, DG) has attracted more and more attention due to its advantages of small investment, clean and environmental protection, high power supply reliability and flexible power generation methods. Connecting DG and loads to form a micro-grid, and connecting it to the large grid and supporting each other in this form is the most effective way to exert the efficiency of the DG system. The microgrid is connected to the grid (generally the distribution network) and operates, and the active power and reactive power can be flexibly exchanged with the main grid. If the main grid fails, the microgrid will be disconnected from the main grid quickly and run in an island mode to ensure the power supply of imp...

AI Technical Summary

Problems solved by technology

Fernando S J et al. used sliding mode control to design the voltage loop. The control system has the advantages of fast response, strong robustness, and invariance to external disturbances and parameter disturbances. Disadvantages of error and unfixed switching frequency

In the actual control system, due to the influence of factors such as system parameter changes, external disturbances, and detection technology limitations, it is usually difficult to obtain an accurate model of the control object, and the matching conditions are often difficult to meet, so that the traditional sliding mode control cannot achieve ideal quality.

[0005] From the above analysis, it can be seen that the existing technology for three-phase inverter control requires high accuracy of the mathematical model of the inverter system, and does not consider the influence of the uncertainty of actual system parameters and external interference on the control performance. The robustness is not strong, it does not meet the requirements of practical application, and it is difficult to realize the project

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