Control method for combined selection and shedding of feeder loads in overload process of power line or power transformer

Abstract

The invention relates to a control method for combined selection and shedding of feeder loads in the overload process of a power line or a power transformer. The control method is characterized by including the following steps that firstly, according to the different overload degrees of the power line or the power transformer, five rounds of load shedding are set; secondly, the overload starting condition of the power line or the power transformer is defined; thirdly, the overload action selection and shedding condition of the power line or the power transformer is defined; fourthly, overload action selection and shedding of the power line or the power transformer are executed. The novel control method for combined selection and shedding of the feeder loads is used for reducing load losses as much as possible while continuous power supply to important users is guaranteed and guaranteeing safe and stable operation of a power grid. According to the control method, multiple independent round levels are set according to the magnitude of currents and overload time delay of the power line or the power transformer, a fixed current value and a fixed time delay value which are independent are set for each round level, the fixed values are set in an inverse time limit mode, and load selection and shedding are accelerated when overload is severe.

Description

technical field [0001] The invention relates to a control method for combined selection and cut-off feeder load of a power line or a power transformer. Background technique [0002] Some substations in the power system have heavy loads, and the capacity of the primary equipment of the power line (or transformer) is relatively high. When one of the power lines (or transformers) running in parallel trips due to a fault, it will cause the untripped power lines (or transformers) to run in overload. Long-term overload operation will cause damage to the power line (or transformer), and measures must be taken to eliminate the primary equipment overload state. [0003] Currently, there are two methods of overload load shedding: shedding loads according to the time-delay and stage-by-wheel shedding and shedding loads in one time according to the inverse time limit, or the total amount of load shedding is accumulated according to the historical load curve of the feeder. The total am...

AI Technical Summary

Problems solved by technology

The total amount of load shedding by these two methods is inaccurate. In order to reliably eliminate the overload operation state of the equipment, a large amount of over-cutting is generally required, and the loss of user load is relatively large.

There are also a small number of users who use the measured feeder load to select and cut, but the selection and cutting method still has a large amount of overcut

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