Adaptive constraint optimization-based three-phase grid-connected inverter robust control method

Abstract

The invention discloses an adaptive constraint optimization-based three-phase grid-connected inverter robust control method. A mathematical model of the three-phase grid-connected inverter under a dq coordinate system is established through a mechanism analysis method and a coordinate conversion method; a power controller and a current robust controller are designed for realizing power outer loop and current inner loop control respectively; an infinite norm and a weighted stacking value of a current tracking error squared value of two robust performance indexes, including robust stability performance and interference suppression performance, are used as an optimization target function for evaluating the control performance; and a condition that the robust stability and the interference suppression performance are both smaller than 1 is used as a constraint condition, and an adaptive constraint optimization-based solver is designed to efficiently realize optimization and setting of a plurality of parameters of the current robust controller. By adoption of the adaptive constraint optimization-based three-phase grid-connected inverter robust control method, the grid-connected current waveform output by the three-phase grid-connected inverter has lower total harmonic distortion and higher robustness and other control performance.

Description

technical field [0001] The invention relates to intelligent control technology in the field of new energy microgrid and power electronics technology, in particular to a robust control method for a three-phase grid-connected inverter based on adaptive constraint optimization. Background technique [0002] As one of the key components in the new energy microgrid, the three-phase grid-connected inverter directly affects the stability, reliability and power quality of the distributed power grid-connected system. It has attracted extensive attention and research and development from academia and industry. Traditional control strategies for three-phase grid-connected inverters mainly include PI control, direct power control, zero-pole configuration control, repetitive control, etc., and have achieved good control effects in different applications, but it is difficult to meet the actual requirements of grid-connected systems. The stable operation requirements of three-phase grid-c...

AI Technical Summary

Problems solved by technology

However, the robust controller obtained by the existing standard H-infinite robust control method is usually a high-order model, which is difficult to be directly realized in actual engineering; the existing loop forming control and sensitivity function design methods are all three-phase grid-connected inverters first The robust control problem of the controller is transformed into a constrained optimization problem based on the minimum infinite norm of the sensitivity function or the minimum square of the current tracking error, and then the genetic algorithm is used to optimize the solution, but the optimization performance index used in this type of method is too simple to meet the actual conditions. The grid-connected system requires comprehensive performance indicators, and the genetic algorithm optimization tool used is too rough to deal with the constraints, it is difficult to obtain high-quality optimization results, and the genetic algorithm itself has many adjustable parameters, making parameter setting difficult

Images