Research On Real-time Dynamic Ampacity Evaluation System For Overhead Cables

As a main part of power transmission system,the current carrying capacity of power cable is an important parameter to ensure its stable operation.Too large current will accelerate the aging of the cable and affect the stability of the power system.Too small current will reduce the utilization rate of the power cable and waste the cost power cable.Therefore,it is necessary to study on the ampcacity of power cable and design a real-time dynamic current carrying capacity evaluation system for power cable.According to the operation condition of air cables,the specific contents of the study are as follows:1)DS18B20,wind speed sensor,illumination sensor and STM32 embedded microcontroller were used to design a real-time monitoring system for environmental parameters.The real-time collection of environmental temperature,environmental wind speed,environmental illumination and other parameters is realized.And the environment parameters were transferred to the host computer with GPRS data transmission module.2)The calculation model of electromagnetic loss of overhead cable is established by ANSYS,and the electromagnetic loss of conductor and metal sheath of cable is obtained.The method of iteration and finite element method were used to complete the evaluation scheme of real-time current carrying capacity,which provides theoretical support for the whole evaluation system.3)VB6.0 was used to design the interface of the system in the host computer and the database storage technology was used to read and write the parameters of power cables.The field calculation was realized by background call of ANSYS.This system can realize the functions of the storage cable parameter database,real-time monitoring and display of environmental parameters,real-time dynamic current carrying capacity calculation and so on.The real-time evaluation of ampacity was realized according to the environment condition.Systems using finite element,analytical calculations and hardware software can accurately calculate the loss of overhead cables and real-time current-carrying capacity.At the same time,the affection of air temperature,light,and wind speed are analyzed.This research can provide advice for the power sector to manage the real-time load.