Electric car power-grid voltage compensation method based on virtual synchronous generator algorithm

Abstract

The invention discloses an electric car power-grid voltage compensation method based on a virtual synchronous generator algorithm, and the method comprises the following steps: 1), employing the virtual synchronous generator algorithm for an electric car grid-connected interface, and carrying out the droop control based on P-f and Q-V; 2), obtaining the output frequency w and phase angle theta of the grid-connected interface through simulating a mechanical equation of a synchronous generator; 3), employing a voltage and current double-closed-loop control strategy based on the dp coordinate system for an electrical equation part; 4), adding virtual impedance control at the electrical equation part, wherein the virtual impedance comprises constant virtual impedance and transient virtual resistance; obtaining virtual voltage drop, and taking a voltage instruction E obtained at step 1) as a voltage ring d-axis instruction ed, wherein eq is equal to zero; respectively calculating the differences between the ed and eq and the virtual voltage drops vvd and vvq, and obtaining a voltage ring output voltage instruction (shown in the description); 5), obtaining a dq-axis modulation signal of the grid-connected interface through the output of a current ring at step 3), and obtaining a switching control signal of a converter switching network through coordinate conversion and PWM, so as to drive a switching network.

Description

Technical field: [0001] The invention belongs to the field of electric vehicle friendly grid connection based on virtual synchronous generator technology, and in particular relates to a voltage compensation method for electric vehicle power grid based on virtual synchronous generator algorithm. Background technique: [0002] New energy electric vehicles can effectively reduce greenhouse gas emissions and reduce environmental pollution, which is one of the important ways to realize the low-carbon development of transportation at this stage. In response to the development and large-scale popularization of electric vehicles, it is of great significance to study the friendly grid connection of electric vehicles and use the charging and discharging capacity of electric vehicles with high penetration rate to provide support for the safe and stable operation of the power grid. [0003] As a mobile distributed energy storage system, new energy electric vehicles generally use power e...

AI Technical Summary

Problems solved by technology

[0004] The purpose of the present invention is to provide a virtual synchronous generator based on virtual synchronous generator technology based on the defect that the electric vehicle friendly grid-connected scheme cannot change the charging and discharging power adaptively to provide voltage compensation for the grid according to the voltage drop of the grid. Electric Vehicle Grid Voltage Compensation Method Based on Synchronous Generator Algorithm

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