Frequency full-response analytical model considering initial state of system

Abstract

The invention relates to a frequency full-response analytical model considering an initial state of a system. The model is characterized in that S1, a dynamic frequency full-response model is established according to a linearized model of each element of a power system and is simplified; S2, the initial state and input of the system are respectively ignored based on the full-response model in theS1, and analytic expressions of the frequency offset and the zero state response and zero input response of the power increment of a low-pressure cylinder in a steam turbine in the time period from tito ti+1 after a sudden change point i are obtained; S3, according to the superposition theorem, a full-response expression of the system frequency offset in the time period from ti to ti+1 after thesudden change point i is obtained through the S2; S4, i is made to be 1, and the process turns to a S5; S5, an analytical expression of the system frequency offset and the power increment of the low-pressure cylinder in the steam turbine in the time period from ti to ti+1 is solved; S6; if i is less than n, i is made to be equal to i+1, and the process turns to the S5; otherwise, the process turnsto a S7; and S7, an analytical expression of the whole dynamic frequency response process of the system is obtained. The model is advantaged in that the frequency response process of the system wheninput such as low-frequency load shedding and unit protection generator tripping occurs or parameters change suddenly when the frequency falls can be analyzed.

Description

technical field [0001] The invention belongs to the field of primary frequency modulation of electric power systems, and relates to a frequency full response analysis model considering the initial state of the system. Background technique [0002] Frequency reflects the balance between active power generation and load in the power system, and is related to the safe and stable operation of the power system. my country has strict requirements on it. When the frequency modulation capability of the system is insufficient, the frequency drop caused by the lack of high power may lead to problems such as low-frequency load shedding of the system. In severe cases, it will cause system disconnection or even system collapse, causing huge social and economic losses. [0003] In recent years, my country's power grid structure and energy structure have undergone tremendous changes. First of all, the installed capacity of new energy such as photovoltaics and wind power is increasing rapi...

AI Technical Summary

Problems solved by technology

[0006] At present, the existing system frequency response model does not consider the impact of the initial state on the system, and cannot analyze the frequency response of the system when the frequency drops, such as low-frequency load shedding, unit protection cut-off, etc.

Images