Research on Grid-Tied Strategy of Matrix Converter Based on Source and Grid Currents Feedback

摘要

Background: A grid-tied strategy of matrix converter (MC) based on the dual-side current closed loop is presented here. Methods: This paper designs dual-closed-loop regulators in which source current and grid current are used as the outer-loop and the inner-loop controlled variables, derives the duty ratio expressions of MC in different time slot, and complete the prototype. The capacitor voltage and the inductance current of the filter are used as the state variables of the inner-loop in system and the virtual rectifier parameters of MC are corrected real time to improve accuracy and to get the unit input-power-factor when it is grid tied. Results: The paper studies the dynamic characteristics of the system in which the virtual-damping is applied, derives the augmented state feedback control equations and transfer functions, gets the optimized control parameters and more feasible closed-loop ac nodes, to enhance the stability of the system. Conclusion: The experiment results, which are involved in the source-side features, grid-tired process of MC, and load change response, show that the MC grid-tied system based on the new strategy has favorable features and unit-power-factor in both source and grid sides.