Control method, device and equipment for virtual synchronous inverters

Abstract

The invention discloses a control method for virtual synchronous inverters. After a power grid is judged to be in an asymmetric fault state by comparing the output current of a virtual synchronous inverter with a protection value, the virtual synchronous inverter is switched from the current virtual synchronous inversion control mode to a hysteresis comparison control mode, wherein the hysteresiscomparison control mode refers to controlling the transient impulse current of the virtual synchronous inverter by using the output of a hysteresis comparator. According to the scheme, because the hysteresis comparison control mode has the advantage of fast response, the fault response speed of the virtual synchronous inverter can be synchronized, and the transient impulse current produced by thevirtual synchronous inverter can be controlled quickly within the normal range of the reference current. The purpose of fast suppression of the transient impulse current produced by a virtual synchronous inverter is achieved. In addition, the invention discloses a control device and equipment for virtual synchronous inverters, which have the same effect.

Description

technical field [0001] The invention relates to the technical field of power grids, in particular to a control method, device and equipment for a virtual synchronous inverter. Background technique [0002] Grid-connected inverters are inverters that connect distributed power sources such as wind energy and solar energy to the grid. Grid-connected inverters are static devices with no mechanical inertia and extremely fast response speeds, and are susceptible to load fluctuations or short-circuit faults. The impact of grid fluctuations. To solve this problem, the grid-connected inverter simulates the inertia of the synchronous generator through the virtual synchronous control strategy, which greatly improves the anti-disturbance ability of the grid-connected inverter. Therefore, compared with other control strategies, the virtual synchronous control strategy is distributed There are absolute advantages in grid connection of conventional energy sources and maintaining stable op...

AI Technical Summary

Problems solved by technology

[0004] At present, the control strategy for the transient inrush current of the virtual synchronous inverter when the power grid is faulty is to switch the virtual synchronous control of the virtual synchronous inverter to PR control in the faulty device to achieve the purpose of controlling the transient inrush current, but Due to the large tr...

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