A grid-connected control method and apparatus for a multi-machine parallel virtual synchronous inverter

Abstract

The invention discloses a grid-connected control method for a multi-machine parallel virtual synchronous inverter. When each virtual synchronous inverter is connected to a main power network in parallel, the voltage synchronization between each virtual synchronous inverter and the main power network can be realized by using the phase angle compensation amount and the angular frequency synchronouscompensation amount. In addition, the current virtual inertia of each virtual synchronous inverter is adjusted to the target virtual inertia by utilizing the equivalent reactance between each virtualsynchronous inverter and the main power network and the maximum angular frequency compensation amount, so as to achieve the purpose of suppressing power oscillation between each virtual synchronous inverter and the main power network. Therefore, when each virtual synchronous inverter is connected to the main power network, the synchronization between the output voltage of each virtual synchronousinverter and the voltage of the main power network is ensured, and the power oscillation problem caused by each virtual synchronous inverter can be avoided when each virtual synchronous inverter can not be connected to the main power network. In addition, the invention discloses a grid-connected control device for a multi-machine parallel virtual synchronous inverter, which has the effect as above.

Description

technical field [0001] The invention relates to the technical field of power grids, in particular to a grid-connected control method and device for multi-machine parallel virtual synchronous inverters. Background technique [0002] Distributed energy technology is an important development direction of future energy technology, which has the advantages of high energy utilization efficiency and small negative impact on the environment. Distributed energy is an energy supply method built on the user side, which can be operated independently or connected to the grid. It is a system that maximizes resources and environmental benefits to determine the mode and capacity, and integrates and optimizes the user's various energy needs and resource allocation conditions. [0003] Inverter-based grid-connection technology is one of the important research contents of distributed energy technology application. Distributed energy is generally connected to the grid through the inverter inte...

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Problems solved by technology

[0005] The purpose of the present invention is to provide a grid-connected control method and device for multi-machine parallel virtual synchronous inverters, so that when multiple virtual synchronous At the same time of voltage synchronization, it solves the problem of power oscillation caused by multiple virtual synchronous inverters connected to the grid

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