Method and system for suppressing DC continuous commutation failure based on rapid forced excitation of phase modifier

Abstract

The invention discloses a method and system for suppressing DC continuous commutation failure based on transient forced excitation of a phase modifier. According to the technical scheme adopted by theinvention, the method comprises the steps of calculating a critical commutation bus voltage of DC commutation failure according to structural parameters and a current operation state of a DC system,and taking the critical commutation bus voltage as a starting threshold value and an exit threshold value of transient forced excitation control of the phase modifier; when a near-zone AC line of a DCconverter station breaks down, enabling the phase modifier to start transient forced excitation control and continuously work in a top value overexcitation state; in the DC commutation failure process, detecting the bus voltage, the active power, the reactive power and the extinction angle of the converter station in real time, and judging whether the risk of the next commutation failure occurs in the commutation failure recovery process of the direct current or not. The method can improve the prediction accuracy of the continuous commutation failure risk of the DC system, and shortens the transient forced excitation starting time of the phase modifier; and the transient reactive power supporting capability of the phase modifier is fully utilized, and the capability of inhibiting continuous commutation failure of the converter station of the phase modifier is improved.

Description

technical field [0001] The invention relates to the field of safety and stability analysis of power systems, in particular to a method and system for suppressing DC continuous commutation failure based on fast and forced excitation of capacitors. Background technique [0002] my country's energy distribution and load distribution show a trend of east-west differentiation. The northwest region has large-scale thermal power and photovoltaic and other new energy sources, and the southwest region has a large amount of hydropower resources, while the load centers are mostly concentrated in the central and eastern coastal areas. Therefore, long-distance and large-scale transmission of power resources has become the trend of my country's future power system. [0003] Compared with the AC transmission method, the DC transmission method has many obvious advantages. DC transmission lines are low in cost, long in life, large in transmission capacity, low in loss, and do not need to in...

AI Technical Summary

Problems solved by technology

[0009] Conventional camera control methods have certain shortcomings in suppressing DC continuous commutation failures, which are mainly reflected in: the start signal comes from the converter station’s prediction logic for continuous commutation failures, and the delay time is long; The excitation control logic remains unchanged, affected by the fluctuation of the AC bus voltage due to commutation failure, the reactive power support capability of the condenser itself is not fully utilized

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