An Active Frequency Adjustment Method Considering Voltage Optimal Control Constraints

Abstract

The present invention proposes an active frequency adjustment method considering the constraints of voltage optimization control. The method includes: obtaining the grid-related data before and after the DC blocking fault of the sending-end power grid; constructing a comprehensive optimization mathematical model of active and reactive power after the DC-fault of the sending-end power grid; The optimal solution of reactive power output; according to the optimization results, determine the active and reactive power output adjustment amount of the generator in the system and the output adjustment amount of the reactive power compensation device after the DC fault of the sending end power grid. The present invention optimizes active power and reactive power at the same time, which not only can realize the active power frequency adjustment after the system DC blocking fault, but also considers the voltage optimization control constraints, and avoids the voltage over-limit phenomenon that may occur after the system active power adjustment. The invention comprehensively considers the requirements of system operation economy and safety, is easy to implement and has high accuracy, and is a practical active frequency adjustment method considering voltage optimization control constraints.

Description

technical field [0001] The invention relates to the technical field of power system operation optimization, in particular to an active frequency adjustment method considering voltage optimization control constraints. Background technique [0002] Due to the uneven distribution of resources and unbalanced regional development, the delivery of large-scale new energy via UHVDC is the preferred solution for the current delivery of new energy. A high proportion of new energy is connected to UHV DC for external transmission, which not only brings huge economic benefits, but also reduces the controllability of the power grid and changes the stability characteristics of the sending-end AC system. The sending-end AC system is prone to a series of frequency stability and Voltage stability problem. [0003] When the UHV DC has a blocking fault, the DC power transmission channel is blocked, and the sending end system has excess power generation, which leads to an increase in the freque...

AI Technical Summary

Problems solved by technology

However, if only the active power adjustment of the sending end system is performed, although it can meet the requirements of the system frequency adjustment control, since the power flow of the high-voltage AC transmission line is light-loaded after the active power adjustment, the line charging capacitor will release a large amount of reactive power, which may cause Steady-state overvoltage phenomenon in local system

[0004] The inventor found in the research that currently active power optimization is mostly used in system frequency adjustment, and the influence of voltage stability constraints and reactive power flow is not considered when performing active power optimization, and the system economy and safety are not well balanced.

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