Active damping stabilization control method for dual-active bridge type micro inverter

Abstract

The invention provides an active damping stabilization control method for a dual-active bridge type micro-inverter, which realizes two active damping stabilization control suitable for different conditions by respectively adopting two modes of connecting an inductor in series with a virtual resistor active damping controller and connecting a capacitor in parallel with the virtual resistor active damping controller. By sampling the voltage of a filter capacitor, connecting a virtual resistor to a grid-side output filter inductor in series or connecting virtual resistors to two ends of the filter capacitor in parallel, and setting a feedback item based on the characteristic of phase shift control of the dual-active bridge type micro-inverter, the grid-connected stability of the micro-inverter is greatly improved, and the total harmonic distortion (THD) of output current is improved. According to the invention, active damping in the control loop is adopted, so that the problems of loss and heat dissipation caused by passive damping are eliminated; meanwhile, the feedback coefficient of the active damping can be flexibly adjusted, so that the active damping stabilization control method can be suitable for different circuit parameters and circuit working conditions and has good universality.

Description

technical field [0001] The invention relates to the technical field of active damping control of micro-inverters, in particular, to a method for controlling active damping stabilization of dual-active bridge-type micro-inverters. Background technique [0002] Micro-inverter generally refers to an inverter with a power of less than or equal to 1000W in a photovoltaic power generation system and with the ability to track the maximum power point at the component level. Unlike centralized and string PV inverter systems, micro-inverters are directly connected to individual PV modules. The advantage is that each component can be independently controlled by MPPT, which can greatly improve the overall efficiency and avoid the DC high voltage, poor low light effect, and barrel effect of centralized inverters. [0003] According to the location and structural characteristics of the DC bus, microinverters can be divided into three categories: DC bus structure, pseudo DC bus structure ...

AI Technical Summary

Problems solved by technology

The active damping control method still has the following problems: the active damping control method is only applicable to the traditional three-phase full-bridge inverter, and the basic working principle and small-signal model of the dual active bridge micro-inverter are both Unlike full-bridge inverters, and dual active-bridge microinverters are single-phase inverters, this active damping method cannot be applied

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