CN-121983978-A - Power grid equipment overload capacity assessment method and device based on thermal state monitoring

CN121983978ACN 121983978 ACN121983978 ACN 121983978ACN-121983978-A

Abstract

The invention discloses a method and a device for evaluating overload capacity of power grid equipment based on thermal state monitoring, and relates to the technical field of power grid equipment state monitoring. A power grid equipment overload capacity assessment method based on thermal state monitoring comprises the steps of collecting static parameters, real-time operation data, load prediction data and environment weather prediction data of each equipment, calculating equipment thermal rated values according to equipment types, environment temperatures, laying modes and operation states by combining the static parameters and the real-time operation data, assessing the equipment potential overload capacity based on the equipment thermal rated values and the real-time operation data, carrying out heating trend prediction according to the load prediction data and the environment weather prediction data to obtain equipment thermal trend prediction results, and generating alarm information and pushing when the equipment temperature exceeds a temperature threshold value in the equipment temperature exceeds a temperature threshold value, the load exceeds the equipment potential overload capacity or the equipment thermal trend prediction results. The invention obviously improves the safety of the operation of the power grid and the utilization rate of equipment.

Inventors

WANG MINGLI
SHI JINYUAN
SU BIAOLONG
SHAO SIYANG
DU HONGWEI
ZHANG YULIN
XIA DONG
ZHOU YAN
QIAO XUE

Assignees

国电南瑞南京控制系统有限公司
国电南瑞科技股份有限公司

Dates

Publication Date: 20260505
Application Date: 20251231

Claims (10)

1. A method for evaluating overload capacity of power grid equipment based on thermal state monitoring, comprising the steps of: Collecting static parameters, real-time operation data, equipment load prediction data and environment weather prediction data of each equipment; According to the equipment type, the environment temperature, the laying mode and the running state, combining the static parameters of the equipment and the real-time running data, dynamically calculating the thermal rated value of the equipment; Evaluating potential overload capabilities of the device based on the device thermal ratings and real-time operational data; According to the equipment load prediction data and the environmental weather prediction data, carrying out temperature rise trend prediction to obtain an equipment thermal trend prediction result; And when the equipment temperature exceeds the temperature threshold, the load exceeds the potential overload capacity of the equipment or the equipment temperature exceeds the temperature threshold in the equipment thermal trend prediction result, generating and pushing alarm information.
2. The method for evaluating the overload capacity of power grid equipment based on thermal state monitoring according to claim 1, wherein when the equipment type is a transformer, classified calculation is performed according to the capacity type, the cooling mode and the operation load type of the transformer, and a pre-stored temperature load coefficient relation table is queried in combination with the ambient temperature, so that a thermal rated value is obtained through calculation; The load types comprise a normal periodic load, a long-term emergency periodic load and a short-term emergency load, and each load type corresponds to different load current per-unit value limit values, hot spot temperature limit values and top-layer oil temperature limit values; the thermal rating is the product of the transformer capacity and the load current per-value limit.
3. The method for evaluating the overload capacity of power grid equipment based on thermal condition monitoring according to claim 1, wherein when the equipment type is a cable, real-time current-carrying capacity is obtained as a thermal rated value by inquiring one or more current-carrying capacity correction coefficient tables and calculating products according to a cable laying mode, an ambient temperature, the parallel laying quantity and a soil thermal coefficient.
4. A method for evaluating overload capacity of a power grid device based on thermal state monitoring according to claim 3, wherein the real-time current capacity calculation formula is: ; In the formula, In order to correct the current-carrying capacity after correction, For a nominal current-carrying capacity at the reference temperature, Is a comprehensive correction coefficient; The comprehensive correction coefficient K is determined by inquiring one or more correction coefficient tables, and the correction coefficients at least comprise one or more of an ambient temperature correction coefficient, an in-air parallel laying correction coefficient, a bridge multi-layer laying correction coefficient, a soil thermal resistance correction coefficient, an in-soil parallel laying correction coefficient and an outdoor sunshade-free correction coefficient.
5. The method for evaluating the overload capacity of the power grid equipment based on the thermal state monitoring according to claim 1, wherein when the equipment type is a transformer, the process of evaluating the potential overload capacity of the equipment is that a pre-stored overload capacity table is inquired according to the current load coefficient, the cooling mode and the environment temperature of the transformer, and the allowable overload coefficient and the duration time of the transformer under the short-term emergency load are obtained according to the initial load coefficient and the environment temperature of the transformer before the short-term emergency load.
6. The method for evaluating the overload capacity of the power grid equipment based on the thermal state monitoring according to claim 1, wherein when the equipment type is a cable, the process of evaluating the potential overload capacity of the equipment is that the real-time current-carrying capacity of the cable is obtained according to the type of the cable, the laying mode and the ambient temperature, and the potential overload capacity of the cable is obtained by subtracting the nameplate rated current of the equipment from the real-time current-carrying capacity of the cable.
7. The method for evaluating the overload capacity of power grid equipment based on thermal state monitoring according to claim 1, wherein the process of predicting the heating trend comprises: Acquiring equipment load prediction data and environment weather prediction data of a specific time period in the future; based on the thermal dynamic model, simulating and calculating a device temperature change track in a prediction period; Identifying a possible temperature peak value and the time for reaching the peak value according to the equipment temperature change track; When the device type is a transformer, the thermodynamic model is expressed as: ; In the formula, Is the difference between the transformer temperature and the ambient temperature; Is the load factor; Is no-load loss; Load loss at rated load; oil temperature rise at rated load; When the device type is cable, the thermodynamic model is expressed as: ; In the formula, Is the difference between the cable temperature and the ambient temperature; Is the effective value of the current flowing through the cable; cable resistivity at 20 ℃; Is the cable length; Is the cross-sectional area of the cable; Is the comprehensive heat transfer coefficient; is the outer surface area of the cable per unit length.
8. The method for evaluating the overload capacity of power grid equipment based on thermal state monitoring according to claim 1, wherein the alarm information at least comprises a unique equipment identifier, an out-of-limit parameter type, a current measured value, a set limit value and recommended treatment measures.
9. A power grid equipment overload capability assessment device based on thermal state monitoring, comprising: the data acquisition module is used for acquiring static parameters, real-time operation data, equipment load prediction data and environmental weather prediction data of each equipment; The overload capacity evaluation module is used for dynamically calculating the thermal rated value of the equipment according to the equipment type, the environmental temperature, the laying mode and the running state by combining the static parameters of the equipment and the real-time running data; Evaluating potential overload capabilities of the device based on the device thermal ratings and real-time operational data; According to the equipment load prediction data and the environmental weather prediction data, carrying out temperature rise trend prediction to obtain an equipment thermal trend prediction result; And when the equipment temperature exceeds the temperature threshold, the load exceeds the potential overload capacity of the equipment or the equipment temperature exceeds the temperature threshold in the equipment thermal trend prediction result, generating and pushing alarm information.
10. A computer readable storage medium having stored thereon a computer program/instruction, which when executed by a processor, implements the steps of the method for assessing overload capabilities of a power network device based on thermal condition monitoring according to any one of claims 1 to 8.

Description

Power grid equipment overload capacity assessment method and device based on thermal state monitoring Technical Field The invention relates to a method and a device for evaluating overload capacity of power grid equipment based on thermal state monitoring, and belongs to the technical field of power grid equipment state monitoring. Background In power system operation, the thermal state of the grid equipment (e.g., transformers, cables, overhead lines, etc.) directly affects its operational safety and life. The equipment is easy to cause insulation aging, equipment damage and even failure and power failure when running in overload or high-temperature environment, and the power supply reliability is seriously affected. At present, the thermal state monitoring of power grid equipment is mostly dependent on regular inspection or fixed rated value operation, and the dynamic evaluation of real-time thermal state and the accurate prediction of overload potential are lacking. Most of the prior art schemes are based on static evaluation of the current state, prospective thermal state prediction cannot be carried out by combining future load change and environmental trend, particularly, under the scene of large load fluctuation and frequent environmental temperature change, overheat risks of equipment are difficult to identify in time, potential overload capacity of the equipment cannot be effectively excavated, and the equipment utilization rate is low or the running risk is high. Disclosure of Invention The invention aims to provide a method and a device for evaluating overload capacity of power grid equipment based on thermal state monitoring, which are used for collecting equipment operation data and environmental parameters in real time, dynamically calculating a thermal rated value of the power grid equipment and accurately evaluating overload potential of the power grid equipment, and leading the thermal state of the equipment to be perceived and early-warned through a thermal trend prediction module so as to improve the safety of the power grid operation and the utilization rate of the equipment. In order to achieve the above purpose, the invention is realized by adopting the following technical scheme. In one aspect, the invention provides a method for evaluating overload capacity of power grid equipment based on thermal state monitoring, which comprises the following steps: Collecting static parameters, real-time operation data, equipment load prediction data and environment weather prediction data of each equipment; According to the equipment type, the environment temperature, the laying mode and the running state, combining the static parameters of the equipment and the real-time running data, dynamically calculating the thermal rated value of the equipment; Evaluating potential overload capabilities of the device based on the device thermal ratings and real-time operational data; According to the equipment load prediction data and the environmental weather prediction data, carrying out temperature rise trend prediction to obtain an equipment thermal trend prediction result; And when the equipment temperature exceeds the temperature threshold, the load exceeds the potential overload capacity of the equipment or the equipment temperature exceeds the temperature threshold in the equipment thermal trend prediction result, generating and pushing alarm information. Optionally, when the equipment type is a transformer, classifying and calculating according to the capacity type, the cooling mode and the operation load type of the transformer, inquiring a pre-stored temperature load coefficient relation table by combining the ambient temperature, and calculating to obtain a thermal rated value; The load types comprise a normal periodic load, a long-term emergency periodic load and a short-term emergency load, and each load type corresponds to different load current per-unit value limit values, hot spot temperature limit values and top-layer oil temperature limit values; the thermal rating is the product of the transformer capacity and the load current per-value limit. Optionally, when the equipment type is a cable, according to the cable laying mode, the environment temperature, the parallel laying quantity and the soil thermal resistance coefficient, obtaining the real-time current-carrying capacity as a thermal rated value by inquiring one or more current-carrying capacity correction coefficient tables and calculating the product. Optionally, the real-time current-carrying capacity calculation formula is: ; In the formula, In order to correct the current-carrying capacity after correction,For a nominal current-carrying capacity at the reference temperature,Is a comprehensive correction coefficient; The comprehensive correction coefficient K is determined by inquiring one or more correction coefficient tables, and the correction coefficients at least comprise one or more of an ambient temperature correction coe