Variable adjustment interval whole-plant AVC-unit reactive power combined control method and system

Abstract

The invention discloses a variable adjustment interval whole-plant AVC-unit reactive power combined control method and system, so as to solve the problem that the whole-plant AVC commissioning rate ofa power plant is low and overcome the defects caused by the low commissioning rate, and belongs to the technical field of hydroelectric generation. The method comprises the following steps: 1, a linkof judging bus voltage of a whole plant and performing reactive power distribution of the whole plant; 2, a whole-plant AVC single-machine set value locking link: setting a single-machine reactive power distribution value lower limit to be locked, automatically exiting the whole-plant AVC when the reactive power distribution value lower limit exceeds the limit value, and giving an alarm; 3, a single-machine reactive power regulation link: dividing the operation conditions of the unit into three types, judging which working condition the unit is in, automatically regulating the reactive powerregulation interval of the unit, enabling the reactive power regulation interval of the unit to better adapt to the operation conditions of the unit, completing reactive power regulation, and responding to a single-machine reactive power set value issued by AVC of the whole plant. On the premise of ensuring the safety of the unit, the reactive power adjustable interval of the unit is dynamically adjusted according to different operating conditions of the unit, so that the reactive power adjusting capacity of the unit is reasonably and fully exerted.

Description

technical field [0001] The invention relates to a method and system for reactive power joint control of the whole plant AVC-units in a variable adjustment interval, in particular to a plant-wide AVC-unit reactive power joint control method in a variable adjustment interval that improves the AVC commissioning rate of the whole plant under a weak power grid. An optimization control method belongs to the technical field of hydropower generation. Background technique [0002] At present, domestic large and medium-sized hydropower plants all adopt plant-wide AVC control and unit reactive power control to achieve reactive power balance and plant-wide busbar voltage regulation. However, due to the high level of safety and stability of the domestic power grid, sufficient reactive power adjustment means, and frequent and large fluctuations in grid voltage rarely occur, the traditional AVC control and unit reactive power control methods can basically meet the operating needs of domest...

AI Technical Summary

Problems solved by technology

[0003] However, for some weak power grids in underdeveloped areas, there is a lack of reactive power adjustment technology, irregular load regulation, poor grid stability, and frequent system voltage fluctuations with large amplitudes are common.

Hydropower plants may need to frequently participate in system voltage regulation, the operating conditions are more complex, and contain higher operational risks. Traditional plant-wide AVC control and unit reactive power control methods are difficult to adapt to the operating needs of weak power grids. Typical phenomenon One is that the AVC commissioning rate of the whole plant is low, only 72.6% according to statistics

However, the low operation rate of AVC in the whole plant may further cause the voltage out of control of the whole plant, human misoperation, interference with operation monitoring, etc., which are not conducive to the safe and stable operation of the power plant.

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