On-line tuning method and device for power system low-frequency load shedding based on frequency trajectory

Abstract

The present invention provides an on-line tuning method and device for low-frequency load shedding of power systems based on frequency locus. By measuring the on-site frequency of the installed bus bar in real time, the on-site frequency offset value and frequency change rate are calculated; the on-site frequency track offset of the bus bar is calculated. area, establish the relationship between the frequency track offset area and the system power deficit, and calculate the system power deficit; according to the ratio of the system power deficit to the total system capacity, determine different low-frequency load shedding schemes; select the load corresponding to the scheme , execute the low-frequency load shedding scheme; set the start mechanism of the power gap calculation program, and determine the start-up of the low-frequency load shedding power gap calculation algorithm according to the frequency change rate value. The present invention calculates the system power deficit by using the in-situ frequency track offset area, and the calculation result is more accurate; based on the calculation result of the system power deficit, the low-frequency load shedding setting scheme applicable to the system power deficit of different sizes is formulated online, and the low-frequency load shedding scheme is more targeted. .

Description

technical field [0001] The invention belongs to the technical field of electric power systems, and in particular relates to an online setting method and device for low-frequency load shedding of electric power systems based on frequency locus. Background technique [0002] Frequency is an important index for the stable operation of power system and power quality. The frequency of the power system is mainly determined by the balance between the active output and the load of the power system. Frequency stability, power angle stability and voltage stability are defined as the three major stability of the current power system. Most power systems use long-distance, high-capacity AC-DC transmission technology. Once the large-capacity transmission channel is out of operation, it will inevitably cause frequency stability problems in the receiving end system. If effective control measures are not taken, the system frequency may collapse, leading to large-scale blackouts in the powe...

AI Technical Summary

Problems solved by technology

There are two main shortcomings in the current low-frequency load shedding setting method: first, neither the traditional method, the semi-adaptive method nor the adaptive method can accurately calculate the power shortage of the current system, resulting in inaccurate low-frequency load shedding and load shedding; second , once the load shedding rounds and the amount of load shedding are set, they will not change due to the actual power shortage event that occurs in the system. For events with a large power shortage, the low-frequency load shedding action is slow, and the system frequency recovery is slow. Small practice, the first round of load shedding is relatively large, and the spinning reserve of the system cannot be fully utilized

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