Calculation method of active power of stable section after UHVDC lockout fault

Abstract

The invention discloses a method for calculating the active power of a stable section after an ultra-high voltage direct current blocking fault. According to the active power imbalance caused by the direct current blocking fault, the method distributes the active power imbalance amount to each generator according to a synchronous power coefficient, and calculates the active power flow of the section at the fault instant. Aiming at the unbalance of active power caused by DC blocking fault and safety control system operation, the active power of generator and load node is determined according tothe static frequency characteristic, and the section active power flow from transient state to steady state is calculated. The active power of generator and load node is determined according to the spinning reserve and climbing rate of generator in the process of recovering to the rated frequency, and the section active power flow in the process of secondary frequency modulation is calculated. The invention respectively calculates the section active power flow in the instant of fault, the transient process transitioning to the steady state and the secondary frequency modulation operation process according to the DC blocking fault, and realizes the fast analysis of the stable section active power under the large-scale active power unbalance quantity.

Description

technical field The invention relates to a method for calculating the active power of a stable section after an UHV DC blocking fault, and belongs to the technical field of power system safety and stability analysis. Background technique UHV DC transmission provides a solid foundation for large-scale consumption of clean energy such as hydropower, wind power, and photovoltaics, and can give full play to the ability of large power grids to optimize energy allocation across regions. The step-wise increase in the scale of UHVDC transmission has led to an increasing proportion of the power delivered by UHVDC in some regional power grids. Once a fault such as UHV DC blocking occurs, the unbalanced power caused by it is very likely to cause the local power grid to run beyond the stable limit, and in severe cases may induce cascading faults or large-scale power outages. Since the frequency modulation power supply capacity of the local grid power supply has gradually approached the...

AI Technical Summary

Problems solved by technology

In the conventional power flow calculation model, the static frequency characteristics of generators and loads are ignored, and the active output of generators other than the balance machine is set to a fixed value, which cannot accurately reflect the adjustment of the output of generators with frequency modulation capabilities as the system frequency changes Happening

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