Inverter reactive current priority distribution method and system under voltage disturbance

Abstract

The invention discloses an inverter reactive current priority distribution method and system under voltage disturbance. The method comprises the following steps that: the power data of a grid-connected point of a new energy unit is acquired; when the new energy unit is in voltage disturbance, an original reactive current adjustment value is calculated according to the power data; a post-dynamic-distribution active current adjustment value is calculated according to the original reactive current adjustment value; the inverter of the new energy unit is adjusted according to the post-dynamic-distribution active current adjustment value and the original reactive current adjustment value, and the power data of the grid-connected point of the new energy unit are re-collected; whether the new energy unit recovers steady-state operation or not is judged according to the re-collected power data. According to the method and system, dynamic distribution control is carried out on the basis of voltage control output, and it is guaranteed that the new energy unit can effectively participate in the voltage control and frequency control of a power system.

Description

technical field [0001] The present invention relates to the field of electric power technology, and more specifically, to a method and system for preferentially distributing reactive current of an inverter under voltage disturbance. Background technique [0002] In the case of large-scale renewable energy penetration into the power system, the frequency regulation and voltage regulation of the power system are still undertaken by conventional synchronous units, while the intermittent, fluctuating and incomplete controllability of renewable energy lead to system frequency and The voltage problem is more prominent. At the same time, during the power grid failure, the new energy units may also be protected and disconnected from the grid, further deteriorating the system stability. Off-grid further deteriorates the system frequency, leading to low-frequency load shedding action, which removes about 5% of the load and causes a major blackout. Therefore, power electronic equipment...

AI Technical Summary

Problems solved by technology

[0003] In order to solve the problem existing in the background technology that in the case of voltage disturbances, abnormalities may be caused by unbalanced distribution of active and reactive currents, the present invention provides a method and system for prioritizing active current distribution of inverters under voltage disturbances. In the case of voltage disturbance, the method and system obtain a scheme that gives priority to reactive current distribution within the range of the inverter's tolerable current by performing dynamic distribution control on the basis of voltage control and frequency control output. The inverter active current priority allocation method under voltage disturbance includes:

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