CN-122021148-A - Method and device for determining heat flow coupling field of oil immersed transformer and electronic equipment

CN122021148ACN 122021148 ACN122021148 ACN 122021148ACN-122021148-A

Abstract

The invention discloses a method and a device for determining a heat flow coupling field of an oil-immersed transformer, and electronic equipment, and relates to the technical field of operation and maintenance of power equipment, wherein the method for determining the heat flow coupling field of the oil-immersed transformer comprises the steps of acquiring monitoring data of the oil-immersed transformer, and carrying out iterative computation on a heat flow coupling model based on all the monitoring data and a bulk heat source field to obtain a coupling simulation result; extracting features from the coupling simulation result and the body heat source field to obtain a time sequence feature set, calibrating the electromagnetic field finite element model and the heat flow coupling model based on the time sequence feature set and all monitoring data to obtain a target electromagnetic field finite element model and a target heat flow coupling model, performing dimension reduction treatment on the target heat flow coupling model to obtain a reduced order model, and determining the heat flow coupling field of the oil-immersed transformer under the current operation working condition by adopting the reduced order model. The invention solves the technical problem of lower efficiency of detecting the heat flow coupling field of the oil immersed transformer in the related technology.

Inventors

DONG XIANG
DUAN JIAYU
DAI RUICHENG
GAO WENSHENG
YAO LEI
ZHOU KAI
SHAO YANG
YI SHUWEI
JIA DONGMING

Assignees

国网北京市电力公司
清华大学

Dates

Publication Date: 20260512
Application Date: 20260123

Claims (10)

1. The method for determining the heat flow coupling field of the oil immersed transformer is characterized by comprising the following steps of: Acquiring monitoring data of the oil immersed transformer under different historical operation conditions, and carrying out iterative computation on a heat flow coupling model based on all the monitoring data and body heat source fields to obtain a coupling simulation result, wherein the body heat source field is obtained through simulation of a pre-constructed electromagnetic field finite element model, the heat flow coupling model at least comprises a plurality of equation expressions, the equation expressions are used for computing in different physical domains, the physical domains at least comprise a solid domain and an oil domain, and the coupling simulation result is obtained through iterative coupling computation on the equation expressions in all the physical domains; Extracting features from the coupling simulation result and the body heat source field to obtain a time sequence feature set; Calibrating the electromagnetic field finite element model and the heat flow coupling model based on the time sequence feature set and all the monitoring data to obtain a target electromagnetic field finite element model and a target heat flow coupling model; And performing dimension reduction treatment on the target heat flow coupling model to obtain a reduced order model, and determining a heat flow coupling field of the oil immersed transformer under the current operation condition by adopting the reduced order model, wherein the heat flow coupling field comprises a temperature field and an oil flow field.
2. The method for determining a thermal flow coupling field of an oil immersed transformer according to claim 1, further comprising, prior to obtaining monitoring data of the oil immersed transformer under different historical operating conditions: Determining a plurality of types of sensors and determining a plurality of candidate mounting positions inside the oil-immersed transformer for each type of sensor, wherein the sensors are used for acquiring the monitoring data; Determining a candidate set based on all of the candidate installation locations; A target mounting location and a target number of each type of the sensor is determined from the candidate set based on a greedy algorithm.
3. The method for determining a thermal flow coupling field of an oil immersed transformer according to claim 1, wherein before performing iterative computation on a thermal flow coupling model based on all the monitoring data and the thermal source field, the method further comprises: Determining structural parameters and material parameters of the oil immersed transformer, and constructing the electromagnetic field finite element model based on the structural parameters and the material parameters; Based on the electromagnetic field finite element model, calculating the volume power loss density of the oil-immersed transformer under a plurality of historical operation conditions, and carrying out grid interpolation on each volume power loss density to obtain a body heat source field, wherein the body heat source field is thermal power density data of each grid unit in an oil field inside the oil-immersed transformer, and the grid units are used for dispersing a physical field of the oil-immersed transformer.
4. The method for determining a thermal flow coupling field of an oil immersed transformer according to claim 1, wherein the step of performing iterative computation on the thermal flow coupling model based on all the monitoring data and the thermal source field to obtain a coupling simulation result comprises: Constructing boundary thermal continuity conditions and combining boundary conditions; And iterating the heat flow coupling model based on all the monitoring data, the body heat source field, the boundary thermal continuity condition and the combined boundary condition to obtain the coupling simulation result.
5. The method of determining a thermal flow coupling field of an oil immersed transformer according to claim 4, wherein the time series feature set at least includes simulation data under a plurality of historical operating conditions, and the step of calibrating the electromagnetic field finite element model and the thermal flow coupling model based on the time series feature set and all the monitoring data to obtain a target electromagnetic field finite element model and a target thermal flow coupling model includes: Calculating a deviation between the simulation data and the monitoring data for each of the historical operating conditions; And under the condition that the deviation is larger than a preset threshold, adjusting parameters of the electromagnetic field finite element model and the heat flow coupling model until all the deviation is smaller than the preset threshold, and obtaining the target electromagnetic field finite element model and the target heat flow coupling model.
6. The method for determining a thermal coupling field of an oil-immersed transformer according to claim 1, further comprising, after determining the thermal coupling field of the oil-immersed transformer under the current operating condition by using the reduced order model: Acquiring monitoring data of a sensor under a next operation condition, and judging a change value between the current operation condition and the monitoring data of the next operation condition; And under the condition that the change value is larger than a preset change threshold value, calibrating the reduced order model to obtain a target reduced order model, wherein the target reduced order model is used for detecting a temperature field and an oil flow field under the next operation condition.
7. The method for determining a thermal coupling field of an oil-immersed transformer according to claim 1, further comprising, after determining the thermal coupling field of the oil-immersed transformer under the current operating condition by using the reduced order model: Determining a plurality of risk indexes based on the temperature field and the oil flow field, and determining the numerical value of each risk index; Based on all the risk indexes and all the numerical values, determining the fault probability of the oil-immersed transformer by adopting a Bayesian network; And determining an operation and maintenance strategy for the oil-immersed transformer based on the fault probability.
8. The utility model provides a determining device of oil-immersed transformer heat flow coupling field which characterized in that includes: The calculation unit is used for acquiring monitoring data of the oil immersed transformer under different historical operation conditions, carrying out iterative computation on a heat flow coupling model based on all the monitoring data and a body heat source field to obtain a coupling simulation result, wherein the body heat source field is obtained through simulation of a pre-constructed electromagnetic field finite element model, the heat flow coupling model at least comprises a plurality of equation expressions, the equation expressions are used for carrying out calculation in different physical domains, and the physical domains at least comprise a solid domain and an oil domain, and the coupling simulation result is obtained through carrying out iterative coupling calculation on the equation expressions in all the physical domains; The extraction unit is used for extracting features from the coupling simulation result and the body heat source field to obtain a time sequence feature set; The calibration unit is used for calibrating the electromagnetic field finite element model and the heat flow coupling model based on the time sequence feature set and all the monitoring data to obtain a target electromagnetic field finite element model and a target heat flow coupling model; The dimension reduction unit is used for carrying out dimension reduction treatment on the target heat flow coupling model to obtain a reduced order model, and determining a heat flow coupling field of the oil immersed transformer under the current operation working condition by adopting the reduced order model, wherein the heat flow coupling field comprises a temperature field and an oil flow field.
9. A computer program product comprising a non-volatile computer readable storage medium storing a computer program which, when executed by a processor, implements a method of determining a thermal flow coupling field of an oil immersed transformer as claimed in any one of claims 1 to 7.
10. An electronic device comprising one or more processors and a memory for storing one or more programs, wherein the one or more programs, when executed by the one or more processors, cause the one or more processors to implement the method of determining the thermal flow coupling field of an oil immersed transformer of any of claims 1-7.

Description

Method and device for determining heat flow coupling field of oil immersed transformer and electronic equipment Technical Field The invention relates to the technical field of operation and maintenance of power equipment, in particular to a method and a device for determining a heat flow coupling field of an oil immersed transformer and electronic equipment. Background The oil immersed power transformer has the functions of voltage transformation and energy transmission, is key equipment for safe and stable operation of a power grid, and is subjected to multiple physical field coupling effects such as power supply, heat, current and the like in the operation process. Currently, the electric-thermal-flow coupling analysis mainly adopts a full-order three-dimensional model of electromagnetic loss, heat source mapping and thermal-flow solving, namely, the power density distribution of iron loss, copper loss, vortex and the like is calculated by using an electromagnetic field model, then mapped into a heat source, and the convection-conduction coupling temperature rise and oil flow field are solved on an oil duct and a structural domain. However, the product-level oil immersed transformer structure presents obvious multi-scale and strong nonlinear characteristics, so that the full-order three-dimensional model has high discrete degree of freedom and high iteration cost, single-working-condition simulation usually requires hours or even days, and online evaluation of an operation and maintenance side is difficult to support in time. And parameters such as heat source spatial distribution, boundary heat exchange coefficient and oil physical properties are different in values in different projects, and the model is highly sensitive to the boundary and the parameters, so that the hot spot temperature rise and the position prediction have larger deviation. Meanwhile, under dynamic working conditions such as abrupt load change, cooling mode switching or local oil duct blockage, the full-order three-dimensional model needs to be repeatedly rebuilt and recalculated, the calculation cost is high, and the heat flow coupling field detection efficiency is low. In view of the above problems, no effective solution has been proposed at present. Disclosure of Invention The embodiment of the invention provides a method and a device for determining a heat flow coupling field of an oil-immersed transformer and electronic equipment, and aims to at least solve the technical problem that the efficiency of detecting the heat flow coupling field of the oil-immersed transformer is low in the related technology. According to one aspect of the embodiment of the application, a method for determining a thermal flow coupling field of an oil-immersed transformer is provided, and comprises the steps of obtaining monitoring data of the oil-immersed transformer under different historical operation conditions, carrying out iterative computation on a thermal flow coupling model based on all the monitoring data and a bulk heat source field to obtain a coupling simulation result, wherein the bulk heat source field is obtained through simulation of a pre-built electromagnetic field finite element model, the thermal flow coupling model at least comprises a plurality of equation expressions, the equation expressions are used for computation in different physical fields, the physical fields at least comprise a solid field and an oil field, the coupling simulation result is obtained through iterative coupling computation on the equation expressions in all the physical fields, a time sequence feature set is obtained through extracting features from the coupling simulation result and the thermal flow source field, the electromagnetic field finite element model and the thermal flow coupling model are calibrated based on the time sequence feature set and all the monitoring data, carrying out dimension reduction processing on the target thermal flow coupling model to obtain a reduced model, and determining the coupling condition of the thermal flow field of the current operation transformer by adopting the reduced model, wherein the thermal flow field coupling condition of the oil-immersed transformer is determined. Further, before acquiring monitoring data of the oil immersed transformer under different historical operating conditions, the method further comprises the steps of determining a plurality of types of sensors, and determining a plurality of candidate installation positions inside the oil immersed transformer for each type of sensor, wherein the sensors are used for acquiring the monitoring data, determining a candidate set based on all the candidate installation positions, and determining target installation positions and target numbers of each type of sensors from the candidate set based on a greedy algorithm. Further, before the coupling simulation result is obtained by carrying out iterative calculation on the heat flow coupling model based on