Jiang Y.,Wanzhou Power Supply Bureau |
Zhou C.-H.,Guangan Power Generation Co. |
Guo J.-F.,Chongqing Runchuang Technology Co. |
Wang J.-G.,Chongqing Runchuang Technology Co.
Gaoya Dianqi/High Voltage Apparatus | Year: 2010
In this paper, a control method to prevent condensation in intelligent outdoor terminal box is presented. It prevents condensation forwardly by collecting the information of temperature and humidity inside and outside of the terminal box and processing the collected information by intelligent method to get the determinant control condition of the heater and the fan. In addition, the intelligent device to prevent condensation has been developed. With the long-term field test in several substations, the experimental device attains favorable effect. Comparing with the traditional device by heating and dehumidifying, the device controls the condensation point in the box directly, and has a better control curve and steady control performance. The new device uses the fan with less amount of exhaust and uses the infrared heater instead of the electrical heater in use, and it dehumidifies quickly, has small temperature rise, short time for heating and obvious energy-saving effect.
Zhu S.,Southwest University |
Wang J.,Southwest University |
Tang C.,Southwest University |
Dai S.,Wanzhou Power Supply Bureau |
Xu Y.,Southwest University
Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering | Year: 2013
The rural power networks play a very important role in the power network in China. The rural networks built in the old days are usually not standardized, and therefore, a lot of problems emerged these days. Such as, most of the transmission line is aged, the insulation ability of the transmission line degraded, the household voltage is relatively low, the distribution network line loss is very high, and so on. Moreover, making some branches and connections without any order, current leakage, as well as the fire risk exist in many places, especially in the rural areas of mainland China. In order to ensure the safety of electrical power supply, the electric network retrofit for the rural areas and the remote peasant households is needed to be performed urgently. As for the rural power network retrofit and newly built projects, it is quite important to reduce the electrical power loss and keep the normal power supply voltage from the economic and reliable points of view. To keep the deviation of 380 V power supply voltage within the range of -10%-7% rated voltage, the distribution transformers are usually located in the center of the load, and economic power supply radius is required to be less than 500 m. In this respect, it is quite important to choose a reasonable location of the distribution transformer for the safety, reliability and economic operation of power networks. As the core work of power transformer planning, the distribution transformer location optimization for rural power network basically indicated the location determination of the distribution transformer according to the local economic and technical index, which had to satisfy the electricity consumption at the same time. The goal of the distribution transformer location optimization is to minimize the loss of the distribution network while ensuring the stability and reliability of power supply. The distribution transformer location optimization, which was closely related with the future electricity demand forecasting for the load point, the requirements of the distribution network planning, and the electric power system operating index, has a great influence on the economic effect of the electric power department and social effect. At present, many researches has been done on the location optimization model and the optimization algorithms of the substation, though less attention has been paid on the location optimization of the distribution transformer. Therefore, it is very urgent to carry on the studies in the field mentioned above. In Chongqing city, as the rural power network mainly distributes in hills and mountainous, the altitude of the load points has an important impact to the location of distribution transformer, at the same time, because of the existence of the sag, the length of the transmission line is not a straight-line distance. For the reasons above, the traditional optimization model used in the location of distribution transformer was modified in this paper. The line correction coefficient (α) which was connected with the sag was introduced, the line distance computational formula according to the altitude of the load points was improved, and the modified optimization model (M-TLOM) was put forward. Then, an optimized location system of distribution transformer (DTLOS 1.0) was developed based on the Visual Basic 6.0. The instance analysis indicated that the modified model could reduce the loss of distribution network.
Zhang M.,Wanzhou Power Supply Bureau |
Zhang D.,Wanzhou Power Supply Bureau |
Yao C.,Chongqing University |
Mi Y.,Chongqing University |
Dong S.,Chongqing University
ICHVE 2012 - 2012 International Conference on High Voltage Engineering and Application | Year: 2012
The leakage current is a main characteristic quantity of contamination level of transmission lines insulator surfaces, measuring insulator leakage current is currently the principal means to monitor the contamination level, but because the environment of transmission lines is very complex, electromagnetic interference will must produce much noise at the time of collecting and testing leakage current, sometime we also get the full wave or half cycle, that means some ways to realize selective measurements, to improve the current sensor's abilities of anti-jamming, selectivity and accuracy when the sensors measure insulator leakage current, an optical fiber sensor was employed to measure leakage current of the insulator strings, which used LED as the photoelectric conversion and light signal stability to detect the current. Some tests in lab were operated that results approved that the optical fiber sensor could achieve selective measurement of leakage current waves, the positive half cycle or negative half cycle, and of cause the full cycle current could be monitored after the differential circuit was improved. It had a great degree of linearity fitting, its sensitivity reached 40mV/mA, and their pertinence coefficients of linear fitting are all more than 99.94%. Its frequency response was 1Hz∼10 kHz, which can meet the basic requirements of the leakage current measurement. © 2012 IEEE.
Ding M.-A.,Wanzhou Power Supply Bureau |
Xiong D.-B.,Wanzhou Power Supply Bureau |
Liu Z.,Wanzhou Power Supply Bureau
Dianli Xitong Baohu yu Kongzhi/Power System Protection and Control | Year: 2010
A principle of breaker control circuit of substation is analyzed, the process of breaker to trip and close on local control and remote control is introduced, and the reason that computerized five-prevention key can't normally jump at local synchronization closing is pointed out. Under the condition that don't increase any equipments and don't change an original operation method, this paper reasonably makes use of original equip inside of component, optimizes control circuit, which makes local control and remote control, synchronization and locking synchronization etc has no abnormality. It works out the problem that computerized five-prevention key don't jump at local synchronization closing.