Photovoltaic virtual synchronous control method based on power tracing

Abstract

The invention discloses a photovoltaic virtual synchronous control method based on power tracing. The method comprises the following steps: adopting a power superposition equation to obtain a power command, obtaining a direct current side reference voltage according to a power tracing method based on polynomial fitting, and after obtaining photovoltaic panel reference power through a voltage loop,obtaining a d-axis active power command through a power outer loop; obtaining a reactive power command through a once voltage regulation equation, and then obtaining a current dq-axis command to carry out current closed loop control. Flexible control for active power is reached by controlling the size and direction of the direct current side reference voltage, and the reactive power is adjusted through the once voltage regulation equation. The step length magnitude of the direct current side reference voltage is obtained through a polynomial fitting method, and the direction is obtained through a power tracing method. Energy storage equipment does not need to be added to an inverter, the frequency and voltage of a power grid can be adjusted, and the stability of the system and preferableregulation effect for frequency voltage can be guaranteed.

Description

technical field [0001] The invention belongs to the field of photovoltaic inverter grid-connected frequency modulation and voltage regulation control, and in particular relates to a photovoltaic virtual synchronous control method based on power tracking. Background technique [0002] With the deterioration of the environment and the aggravation of the energy crisis, new energy sources such as photovoltaics and wind power are playing an increasingly important role in social development. At the same time, distributed power generation technology is developing rapidly and has become a research hotspot at home and abroad. [0003] At present, with the continuous integration of new energy sources such as photovoltaics and wind power into the grid, the installed capacity of traditional synchronous generators continues to decline. Therefore, the penetration rate of new energy is gradually increasing, so that the rotational inertia and damping of the power grid are relatively reduced...

AI Technical Summary

Problems solved by technology

[0009] The purpose of the present invention is to solve the problem that the centralized photovoltaic inverter cannot regulate the frequency and voltage of the power grid, and provide a photovoltaic virtual synchronization control method based on power tracking. This method does not need to add additional energy storage equipment, so that the traditional photovoltaic inverter has FM and voltage regulation function

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