Active damping optimization method for grid-connected current control of l-type grid-connected inverter

Abstract

The invention discloses an active damping optimization method for grid-connected current control of an L-type grid-connected inverter, which solves the problem of instability of the control system due to the existence of digital control delay, and solves the problem caused by compensation delay The problem of insufficient phase margin in the mid-band. It specifically includes the following steps: Obtain the current reference given value i according to the system sampling L_ref and actual current sampling value i L The difference Δi of the one-beat delay output e . The current prediction method is added, and the predicted inductor current is taken as the research object, and the delay link is compensated. The essence of adding an active damping optimization method to the current loop is to add a second-order differential feedback link to the current loop, which solves the problem that the addition of the active high-frequency damping method causes the system The resonance peak caused by the time improves the system stability, expands the current control gain range, and reduces the system dynamic and static errors.

Description

technical field [0001] The invention belongs to the technical field of grid-connected current control for power quality optimization, and in particular relates to an active damping optimization method for grid-connected current control of an L-type grid-connected inverter. Background technique [0002] Due to the increasingly serious problems of environmental pollution and fossil energy crisis, in order to meet energy demand, new energy has been widely developed and utilized. Distributed power generation system has become a research hotspot in recent years. get rapid development. As the core part of distributed power generation, the grid-connected inverter is required to have extremely high output power factor (PF) and extremely low output current total harmonic distortion (THD). Since the grid-connected system has high requirements on power quality, it is necessary to control the output current of the power generation system in order to meet the grid-connected requirements...

AI Technical Summary

Problems solved by technology

[0005] The purpose of the present invention is to provide an active damping optimization method for grid-connected current control of an L-type grid-connected inverter, to solve the problem of low and high-frequency harmonics in the current loop of the existing grid-connected inverter, and to increase the control gain There is a contradiction between improving the system stability margin

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