Method for improving wireless internet stability of multiple inverters in microgrid by utilizing virtual impedance

Abstract

The invention discloses a method for improving the wireless internet stability of a plurality of inverters in a microgrid by utilizing virtual impedance. The method comprises the following steps of: (1) calculating a droop control coefficient according to the requirement of the microgrid on power quality; (2) estimating a grid line parameter and calculating the stable range of the droop coefficient; (3) substituting the droop coefficient calculated in the step (1) into the range calculated in the step (2) for verifying; if the droop coefficient is not in the stable range, performing a step (4); if the droop coefficient can stabilize completely, performing a step (5); (4) according to a result calculated in the step (3), properly changing virtual inductance or resistance and repeating the step (2) and the step (3) in turn; and (5) realizing the droop control of the virtual impedance. In the method, feedback control is performed on an output voltage by utilizing output current of each micro power supply per se in the microgrid, so as to fulfill the aim of improving the stability of an overall microgrid system and save line conductors.

Description

Technical field: [0001] The technology relates to improving the stability of wireless networking of multiple inverters in a micro-grid, and belongs to a method for optimizing and improving the power distribution of multiple micro-sources in a micro-grid and improving the stability of the entire micro-grid system. Background technique: [0002] At present, the current sharing control technology of the microgrid is mainly divided into two types: master-slave control and peer-to-peer control. Because master-slave control requires communication lines, on the one hand, it will greatly increase the cost, on the other hand, the operation of the microgrid is greatly affected by the environment, and in some harsh environments, it may not be installed and used at all. In the peer-to-peer control technology, the most widely used technology is droop control, but the traditional droop control technology has relatively strict requirements on the impedance of the line. relatively strict. ...

AI Technical Summary

Problems solved by technology

At present, there are two solutions, one is to connect the inverters through communication lines, the cost is high, and communication is difficult under certain geographical conditions, it is difficult to be universally applicable; the other is to use droop control technology Perform wireless parallel connection between inverters

However, when the current technology deals with the wireless parallel connection of inverters, it often only relies on the selection of the droop coefficient or the improvement of the droop control method to achieve the purpose of providing system stability. lead to system instability

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