A Distributed Infrared Temperature Monitoring System Based on Embedded Technology and Visualization Technology

Yuyin Zhang,Likai Liang 보안공학연구지원센터 2016 International Journal of Smart Home Vol.10 No.2

For the contradictory issues of the transmission rate and flexibility in the current temperature system, this paper puts forward a novel fast rate, high flexibility, and visualization monitor system, and presents its architecture principle design and software-hardware of the whole system. Controller area network (CAN) bus acting as multi-host and high-speed field bus is selected to design the distributed communication system, ZigBee technology based on CC2530 and embedded system centered with ARM Cortex-M3 microprocessor STM32F103VET6 are selected to design the flexible data acquisition network, and embedded Ethernet is select to design remote and distributed monitoring. Based on the distributed system, visual monitoring software is developed; it can achieve data display, data query, and real-time monitoring and give an early alarming of accidents caused by temperature. After a number of experiments show that the system is stable, temperature flexible, highly real-time, and the temperature measurement accuracy can be up to 99.37%.

Analysis on Ampacity of Overhead Transmission Lines Being Operated

Zhijie Yan,Yanling Wang,Likai Liang 한국정보처리학회 2017 Journal of information processing systems Vol.13 No.5

Dynamic thermal rating (DTR) system is an effective method to improve the capacity of existing overheadline. According to the methodology based on CIGRE (International Council on Large Electric systems)standard, ampacity values under steady-state heating balance can be calculated from ambient environmentalconditions. In this study, simulation analysis of relations between parameters and ampacity is described asfunctional dependence, which can provide an effective basis for the design and research of overheadtransmission lines. The simulation of ampacity variation in different rating scales is described in this paper,which are determined from real-time meteorological data and conductor state parameters. To test theperformance of DTR in different rating scales, capacity improvement and risk level are presented. And theexperimental results show that the capacity of transmission line by using DTR has significant improvement,with low probability of risk. The information of this study has an important reference value to the operationmanagement of power grid.

Analysis on Ampacity of Overhead Transmission Lines Being Operated

Yan, Zhijie,Wang, Yanling,Liang, Likai Korea Information Processing Society 2017 Journal of information processing systems Vol.13 No.5

Dynamic thermal rating (DTR) system is an effective method to improve the capacity of existing overhead line. According to the methodology based on CIGRE (International Council on Large Electric systems) standard, ampacity values under steady-state heating balance can be calculated from ambient environmental conditions. In this study, simulation analysis of relations between parameters and ampacity is described as functional dependence, which can provide an effective basis for the design and research of overhead transmission lines. The simulation of ampacity variation in different rating scales is described in this paper, which are determined from real-time meteorological data and conductor state parameters. To test the performance of DTR in different rating scales, capacity improvement and risk level are presented. And the experimental results show that the capacity of transmission line by using DTR has significant improvement, with low probability of risk. The information of this study has an important reference value to the operation management of power grid.

Short-Term Wind Speed Forecast Based on Least Squares Support Vector Machine

Wang, Yanling,Zhou, Xing,Liang, Likai,Zhang, Mingjun,Zhang, Qiang,Niu, Zhiqiang Korea Information Processing Society 2018 Journal of information processing systems Vol.14 No.6

There are many factors that affect the wind speed. In addition, the randomness of wind speed also leads to low prediction accuracy for wind speed. According to this situation, this paper constructs the short-time forecasting model based on the least squares support vector machines (LSSVM) to forecast the wind speed. The basis of the model used in this paper is support vector regression (SVR), which is used to calculate the regression relationships between the historical data and forecasting data of wind speed. In order to improve the forecast precision, historical data is clustered by cluster analysis so that the historical data whose changing trend is similar with the forecasting data can be filtered out. The filtered historical data is used as the training samples for SVR and the parameters would be optimized by particle swarm optimization (PSO). The forecasting model is tested by actual data and the forecast precision is more accurate than the industry standards. The results prove the feasibility and reliability of the model.

Dynamic Thermal Rating of Transmission Line Based on Environmental Parameter Estimation

Sun, Zidan,Yan, Zhijie,Liang, Likai,Wei, Ran,Wang, Wei Korea Information Processing Society 2019 Journal of information processing systems Vol.15 No.2

The transmission capacity of transmission lines is affected by environmental parameters such as ambient temperature, wind speed, wind direction and so on. The environmental parameters can be measured by the installed measuring devices. However, it is impossible to install the environmental measuring devices throughout the line, especially considering economic cost of power grid. Taking into account the limited number of measuring devices and the distribution characteristics of environment parameters and transmission lines, this paper first studies the environmental parameter estimating method of inverse distance weighted interpolation and ordinary Kriging interpolation. Dynamic thermal rating of transmission lines based on IEEE standard and CIGRE standard thermal equivalent equation is researched and the key parameters that affect the load capacity of overhead lines is identified. Finally, the distributed thermal rating of transmission line is realized by using the data obtained from China meteorological data network. The cost of the environmental measurement device is reduced, and the accuracy of dynamic rating is improved.

Short-Term Wind Speed Forecast Based on Least Squares Support Vector Machine

Yanling Wang,Xing Zhou,Likai Liang,Mingjun Zhang,Qiang Zhang,Zhiqiang Niu 한국정보처리학회 2018 Journal of information processing systems Vol.14 No.6

There are many factors that affect the wind speed. In addition, the randomness of wind speed also leads to lowprediction accuracy for wind speed. According to this situation, this paper constructs the short-timeforecasting model based on the least squares support vector machines (LSSVM) to forecast the wind speed. The basis of the model used in this paper is support vector regression (SVR), which is used to calculate theregression relationships between the historical data and forecasting data of wind speed. In order to improvethe forecast precision, historical data is clustered by cluster analysis so that the historical data whose changingtrend is similar with the forecasting data can be filtered out. The filtered historical data is used as the trainingsamples for SVR and the parameters would be optimized by particle swarm optimization (PSO). Theforecasting model is tested by actual data and the forecast precision is more accurate than the industrystandards. The results prove the feasibility and reliability of the model.

Electromagnetic Environment of Transmission Line Based on Full Parameter Online Estimation

Zidan Sun,Xiaofeng Zhou,Likai Liang,Yang Mo 한국정보처리학회 2020 Journal of information processing systems Vol.16 No.2

The parameters of transmission lines have an influence on the electromagnetic environment surrounding theline. This paper proposes a method based on phasor measurement unit (PMU) and supervisory control and dataacquisition (SCADA) to achieve online estimation of transmission line full parameters, such as resistance,reactance and susceptance. The proposed full parameter estimation method is compared with the traditionalmethod of estimating resistance independently based on SCADA system. Then, the electromagnetic environmentis analyzed based on the different parameter estimation methods. The example results illustrate that onlineestimation of transmission line full parameters is more accurate in the analysis of electromagnetic environment,which further confirms its necessity and significance in engineering application.

Dynamic Thermal Rating of Transmission Line Based on Environmental Parameter Estimation

Zidan Sun,Zhijie Yan,Likai Liang,Ran Wei,Wei Wang 한국정보처리학회 2019 Journal of information processing systems Vol.15 No.2

The transmission capacity of transmission lines is affected by environmental parameters such as ambienttemperature, wind speed, wind direction and so on. The environmental parameters can be measured by theinstalled measuring devices. However, it is impossible to install the environmental measuring devicesthroughout the line, especially considering economic cost of power grid. Taking into account the limitednumber of measuring devices and the distribution characteristics of environment parameters and transmissionlines, this paper first studies the environmental parameter estimating method of inverse distance weightedinterpolation and ordinary Kriging interpolation. Dynamic thermal rating of transmission lines based on IEEEstandard and CIGRE standard thermal equivalent equation is researched and the key parameters that affect theload capacity of overhead lines is identified. Finally, the distributed thermal rating of transmission line isrealized by using the data obtained from China meteorological data network. The cost of the environmentalmeasurement device is reduced, and the accuracy of dynamic rating is improved.

Power Cable Ampacity and Influential Factors Analysis under Operation

Tong, Qiang,Qi, Jianping,Wang, Yanling,Liang, Likai,Meng, Xiangxing,Zhang, Qiang Korea Information Processing Society 2018 Journal of information processing systems Vol.14 No.5

With the increasing of urban electricity demand, making the most use of the power cable carrying capacity has become an important task in power grid system. Contrary to the rated ampacity obtained under extremely conservative conditions, this paper presents the various steady value of cable ampacity by using the changing surrounding parameters under operation, which is based on cable ampacity calculation equation under the IEC-60287 standard. To some degree, the cable ampacity analysis of actual surroundings improves the transmission capacity of cables. This paper reveals the factors that influence cable ampacity such as insulating layer thickness, allowable long-term conductor temperature, the ambient temperature, soil thermal resistance coefficient, and so on, then gives the class of the influence of these parameters on the ampacity, which plays a great role in accurately calculating the real-time ampacity and improving the utilization rate of cable in the complex external environment condition. Furthermore, the transient thermal rating of the cable is analyzed in this paper, and temperature variation of the conductor under different overload conditions is discussed, which provides effective information for the operation and control of the system.

Dynamic Thermal Rating of Overhead Transmission Lines Based on GRAPES Numerical Weather Forecast

Yan, Hongbo,Wang, Yanling,Zhou, Xiaofeng,Liang, Likai,Yin, Zhijun,Wang, Wei Korea Information Processing Society 2019 Journal of information processing systems Vol.15 No.4

Dynamic thermal rating technology can effectively improve the thermal load capacity of transmission lines. However, its availability is limited by the quantity and high cost of the hardware facilities. This paper proposes a new dynamic thermal rating technology based on global/regional assimilation and prediction system (GRAPES) and geographic information system (GIS). The paper will also explore the method of obtaining any point meteorological data along the transmission line by using GRAPES and GIS, and provide the strategy of extracting and decoding meteorological data. In this paper, the accuracy of numerical weather prediction was verified from the perspective of time and space. Also, the 750-kV transmission line in Shaanxi Province is considered as an example to analyze. The results of the study indicate that dynamic thermal rating based on GRAPES and GIS can fully excavate the line power potential without additional cost on hardware, which saves a lot of investment.