Method for improving stability of sending-end power grid by utilizing static var compensator

Abstract

The invention discloses a method for improving the stability of a sending-end power grid by utilizing a static var compensator. The problems of voltage stability and dynamic stability of a sending-endpower grid are solved. Voltage control and damping control of the static var compensator are integrated, and the intensity of the voltage control and the damping control of the static var compensatoris adjusted through control parameters in different stages of power grid development, so that the voltage stability and the dynamic stability of a sending-end power grid both meet stable operation requirements. The method can enhance the adaptive capacity of the static var compensator, and has the advantages of improving the power supply reliability of the sending-end power grid and ensuring thestable operation of the power grid.

Description

technical field [0001] The invention belongs to the field of power system voltage and dynamic stability, and particularly relates to a method for improving the stability of a power grid at a sending end by using a static var compensator. Background technique [0002] With the rapid development of the power supply and load of the power grid, the transmission power of existing and new transmission lines is getting heavier and heavier. In order to increase the transmission power of existing transmission lines and minimize the loss of transmission lines, it is necessary to realize reactive power control of transmission lines. With the emergence and application of thyristors, a new type of thyristor-based reactive power control device has been produced, which has a very fast response speed. Using this fast response characteristic, the damping control function can also be added to the voltage and reactive power. In control, static var compensator, as a thyristor-based fast reactiv...

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Problems solved by technology

[0003] my country's current power grid is limited by the reverse distribution of energy and load centers. Domestic large-scale wind power and photovoltaics generally adopt the development model of "centralized development and long-distance transmission". Long distance, little or no load access, weak grid structure, and the characteristics of weakly connected sending-end grid, its voltage and reactive power fluctuate greatly, which is easy to cause voltage over-limit, etc., and may also be caused by low / High-voltage ride-through causes large-scale new energy off-grid, affecting the safe and stable operation of the grid

[0004] In addition to wind power and photovoltaic energy, some power grids also have some thermal power and hydropower energy. Because their scale is relatively small compared with new energy sources, and when power is supplied to distant places through weakly connected sending-end power grids, the power grid is prone to weakly damped oscillation modes. After the power grid suffers from small disturbances and serious faults, there will be long-term power oscillations in the power grid that cannot be calmed down quickly, which will also affect the safe and stable operation of the power grid

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