Checking method and system of high-cycle cutting machine configuration scheme

Abstract

The present invention provides a checking method and system of a high-cycle cutting machine configuration scheme of a multi-DC feed asynchronous operation grid. According to the checking method, through using simulation model simulation, the condition of a grid system after a fault in a forecast fault set happens is calculated to obtain a simulation calculation result, the forecast fault set comprises a traditional grid external feed section breaking fault and also comprises the influence of a non-synchronous operation grid fault on a researched grid frequency, and the high-cycle cutting machine configuration scheme can be checked and corrected so as to obtain a scheme which satisfies a configured multi-DC feed asynchronous operation grid operation requirement. According to the checking method of the high-cycle cutting machine configuration scheme of the multi-DC feed asynchronous operation grid, the factor consideration is comprehensive, the operability is strong, the practical value is high, and the market prospect is good.

Description

technical field [0001] The invention relates to the field of electric power system control, in particular to a method and system for checking the configuration of high-frequency cut-off machines in a power grid with multi-direct current transmission and asynchronous operation. Background technique [0002] With the increasing power of DC transmission, the risk of safe and stable operation of the system brought about by the parallel operation of AC and DC is becoming more and more prominent. In order to avoid large-scale power outages when multiple faults occur in the power grid, the grid planning gradually considers the implementation of asynchronous interconnection grids, that is, there is no AC connection line between the two AC systems, but only through the DC line, and the generator rotors in the two systems do not need to be connected. keep in sync. Although the asynchronous interconnected grid has greatly improved the stability of the system's transient power angle, t...

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Problems solved by technology

[0004] (1) When the outgoing DC is blocked, the frequency of the power grid at the sending end increases due to the instantaneous power surplus after the fault. For single-circuit large-capacity DC, unipolar blocking occurs, according to the "Guidelines for Safety and Stability of Power Systems (DL755-2001) 》, the system cannot take stable control measures, and the sending-end power grid may cause the first round of high-frequency cut-off due to the frequency increase, which does not meet the safety and stability standards of the power grid's ability to withstand large disturbances;

[0005] (2) Considering the more serious situation, when the outgoing DC multiple circuits are blocked at the same time and the stability control device refuses to operate, the power grid at the sending end is seriously overpowered. If the duration is long, it may cause the overspeed protection of the thermal power unit to operate disorderly;

[0006] (3) During the process of multiple DC commutation failures in the sending-end grid caused by the failure of the receiving-end grid, the frequency of the sending-end grid may cause the high-cycle switching device to operate. When the fault disappears and the DC power gradually recovers, the sending-end grid will resume The low frequency load shedding device will operate due to the frequency reduction due to power shortage

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