Method for calculating power fluctuation peak value of alternating current tie line under impacts of direct current phase changing failure

Abstract

The invention provides a method for calculating a power fluctuation peak value of an alternating current tie line under impacts of direct current phase changing failure. The method includes the steps of firstly, obtaining a direct current power curve within a direct current phase changing failure period, and calculating n-circuit direct current equivalent phase changing failure lasting time tau and natural oscillation frequency omega<n> and the damping ratio zeta of a large regional grid regional oscillation mode; secondly, building a power oscillation linearization second-order model of the alternating current tie line; thirdly, obtaining the power fluctuation peak value, the peak value power transfer ratio and the peak value time of the alternating current tie line. Compared with the prior art, the method for calculating the power fluctuation peak value of the alternating current tie line under the impacts of the direct current phase changing failure has the advantages that various parameters of the power fluctuation peak value of the alternating current tie line can be rapidly and accurately obtained, a technical person can easily determine the tie line operation power limit and a power grid operation mode, and take effective power control and protection measures, and the safe and stable operation level of a power system can be improved.

Description

technical field [0001] The invention relates to a method for calculating the peak value of power fluctuation of an AC tie line, in particular to a method for calculating the peak value of power fluctuation of an AC tie line under the impact of DC commutation failure. Background technique [0002] HVDC transmission is widely used in the field of power grid networking due to its characteristics of large transmission capacity, long transmission distance and flexible and adjustable transmission power. However, when the AC system at the receiving end of the power grid fails, it is easy to cause the commutation failure of the HVDC transmission system. For example, in 2010, an event occurred in the Southern Power Grid where the commutation failure of 5 DC lines at the same time was caused by the failure of the AC line; on August 7, 2011 In the early morning of August 2012, affected by the typhoon "Plum Blossom", the 500kV line of the East China Power Grid had multiple failures, res...

AI Technical Summary

Problems solved by technology

With the high-density connection of multiple circuits of large-capacity DC to the AC grid, the interaction between AC and DC systems becomes more complex

During the failure of multiple DC commutation, a large amount of power is interrupted instantaneously, causing energy impact on the regional AC tie line, threatening the safe and stable operation of the regional power grid

In the existing technology, the research on the calculation of the power fluctuation amplitude of the tie-line is mainly the calculation of the peak power fluctuation of the tie-line after the power shortage fault occurs in the system, such as the shutdown and DC block, and the steady-state or random power fluctuation on the tie-line However, these methods are not suitable for calculating the peak value of tie-line power fluctuation under the impact of DC commutation failure

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