Dual-mode switching control method and system for new energy grid-connected inverter

Abstract

The invention discloses a dual-mode switching control method and system for a new energy grid-connected inverter, and belongs to the field of power control. The control method comprises the following steps: operating in a self-synchronization control mode under a steady-state operation condition, and considering the performance of current while having an active support capability; when the voltage of the power grid drops, a constant AC voltage control mode is switched, reactive compensation is provided for the system, and good low-voltage ride-through capability is achieved; automatic switching is achieved through the grid-connected point voltage drop depth D, the switching time is shortened, the low-voltage ride-through active recovery requirement can be met by configuring the proper active recovery slope, and the stability of the new energy grid-connected system is improved.

Description

Technical field [0001] The invention relates to the field of power control, in particular to a new energy grid-connected inverter dual-mode switching control method and system. Background technique [0002] Our country is actively building a new generation power system with new energy power generation as the main body. With the rapid development of new energy and the continuous expansion of the scale of grid-connected power generation, power electronics grid-connected interface systems are becoming increasingly high-proportioned. However, new energy power generation such as photovoltaic and wind power is greatly affected by weather factors, resulting in a reduction in the voltage and frequency support capabilities of the new energy grid-connected system. Therefore, the study of control strategies for new energy grid-connected inverters with good voltage and frequency support capabilities has become a current research hotspot. [0003] In recent years, experts and scholars ...

AI Technical Summary

Problems solved by technology

This control method has good voltage and frequency support capabilities, but lacks current control capabilities

[0007] The Chinese Invention Patent Application Specification (CN113595147A) entitled "Virtual Synchronous Generator Control Method Based on Model Predictive Control" provides a control method for generating reference current by collecting system current and voltage in real time and using the virtual synchronous generator control method , this control method properly reduces power fluctuations and optimizes the transient process of the system, but it is not adaptable to the power grid and the control method is complicated

[0008] In short, the existing new energy grid-connected inverter control strategy is difficult to ensure good voltage and current waveform quality under steady-state operation and voltage and current amplitude within the rated range under transient operation.

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