Safe operation control method of grid-connected converter under grid fault

Abstract

The invention provides a safety running control method for a grid-connected current transformer under a power grid fault. The method comprises the following steps of s1, determining a parameter limitation value for safety running of the grid-connected current transformer, wherein the parameter limitation value comprises an active power fluctuation margin limitation value and a phase current limitation value; s2, setting an active power reference value and a reactive power reference value containing a positive-sequence component and a negative-sequence component under a rotating coordinate system, allocating the positive-sequence components and the negative-sequence components of active power and reactive power according to the parameter limitation value, and outputting the active power reference value and the reactive power reference value after allocating; and s3, calculating an output current reference value of the grid-connected current transformer according to the allocated active power reference value and the reactive power reference value containing the positive-sequence component and the negative-sequence component under the rotating coordinate system, and controlling the grid-connected current transformer to output current according to the current reference value. Through the above method, factors such as phase current and power fluctuation are comprehensively considered, the reference current is accurately output and controlled, the safety running of the grid-connected current transformer under the power grid fault can be effectively ensured, the normal working and the service lifetime of the grid-connected current transformer are guaranteed, and an effective support can be formed for a power grid.

Description

technical field [0001] The invention relates to a control method of power grid equipment, in particular to a control method for safe operation of a grid-connected converter under a grid fault. Background technique [0002] With the extensive application of new energy power generation technology, the grid-connected inverter, as one of its core hardware, is the interface connecting the power grid and new energy power generation; as the scale of the power grid becomes larger and larger, a large number of grid-connected converters disconnect when the power grid fails. The network will have a non-negligible impact on the power grid. [0003] In order to realize the safe operation of grid-connected converters in the case of grid faults, commonly used control methods can limit the output current of the converters on the premise of meeting different positive and negative sequence voltage compensation objectives, and meet the requirement that the converters output no current flow. s...

AI Technical Summary

Problems solved by technology

[0003] In order to realize the safe operation of grid-connected converters in the case of grid faults, commonly used control methods can limit the output current of the converters on the premise of meeting different positive and negative sequence voltage compensation objectives, and meet the requirement that the converters output no current flow. Safe operating conditions, but do not take into account the limitation of active power fluctuations, resulting in impact on grid-connected converters

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