Adaptive power equalizing and voltage recovery control method for island micro-grid

Abstract

The invention provides an adaptive power equalizing and voltage recovery control method for an island micro-grid. Various inverters obtain respective output voltages and output currents through a voltage sensor and a current sensor; active powers and reactive powers output by the inverters are calculated; the mean active power and the mean reactive power are obtained through a low-pass filter; by a sampling period control method, the inverters achieve communication-free power equalization by communication-free improved voltage droop control and traditional frequency droop control; various inverters are distributed with the same voltage droop coefficients and frequency droop coefficients; given voltages of voltage closed-loops are synthesized; voltage recovery is added to improved voltage droop control; coordination control of power equalizing and voltage recovery is achieved by a local pulse; and meanwhile, power equalizing and voltage recovery are achieved. The adaptive power equalizing and voltage recovery control method has the advantages of being high in reliability, convenient to control and the like.

Description

technical field [0001] The invention relates to the field of micro-grid control, in particular to a self-adaptive power sharing and voltage recovery control method for isolated island micro-grid without communication. Background technique [0002] In recent years, microgrids have attracted widespread attention due to their miniature, clean, friendly, autonomous, and plug-and-play characteristics. It is an organic combination of distributed power generation units, loads, and energy storage devices. It can be connected to the public grid Connection - grid-connected operation mode, and off-grid operation - island operation mode, forming an environmentally friendly power generation method. [0003] Among them, the power sharing of each distributed generation unit in the island microgrid is very important to ensure its reliable, safe, and long-term stable operation. Traditional droop control has been widely used in microgrids because of its advantage of no interconnection wires. ...

AI Technical Summary

Problems solved by technology

However, in the island microgrid, the output power of traditional droop control inverters is distributed according to the line impedance, and the balance of active power cannot be adjusted adaptively; since the frequency is a global variable, the reactive power controlled by frequency is evenly distributed

Therefore, although the traditional droop control has the advantages of good redundancy, no communication, scalability, plug and play, etc., it also has defects such as uneven power sharing and voltage offset ratings.

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