Droop control method and device and current transformer

Abstract

The invention relates to a droop control method and device and a current transformer, and belongs to the field of microgrid control. The droop control method disclosed by the invention comprises the following steps: detecting the voltage, frequency, active power and reactive power at the output end of the current transformer in real time; if the voltage and frequency are not out-of-limit, carryingout controlling on a set droop control curve; if the voltage or frequency is out-of-limit, setting the output voltage and frequency of the current transformer in the droop control curve to be corresponding voltage constant value and frequency constant value, and adjusting rated active power and rated reactive power in the droop control curve so as to carry out controlling. The regulating range ofdroop coefficient is increased, and simultaneously, an out-of-limit condition cannot appear for the voltage and frequency; the method can preferably realize rapid adaptation on gird-connected point voltage and frequency change, so that when the load change is relatively complex, the voltage and frequency at a grid-connected point are relatively stable.

Description

technical field [0001] The invention relates to a droop control method, device and converter, belonging to the field of micro-grid control. Background technique [0002] With the rapid development of new energy technologies such as photovoltaics and wind power, their grid-connected capacity is increasing. However, new energy sources such as photovoltaics and wind power have large randomness, and the output power is not stable. In actual use, they often need to be used together with energy storage units. In actual use, because new energy sources often adopt distributed configurations to form micro-networks, and in actual use, it is likely that off-grid parallel operation will be required. At this time, a series of problems such as parallel circulating current are prone to occur. In order to avoid such problems, a common method is to add a droop control link in the control of the converter, so that the converter can run stably. [0003] Traditional droop control is based on ...

AI Technical Summary

Problems solved by technology

[0005] The purpose of the present invention is to provide a droop control method, device and converter, which are used to solve the problem that the traditional droop control method is difficult to balance the control sensitivity and regulation range

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