| There are a lot of limitations in domestic power transmission network. The efficient and capacity of high voltage power transmission is low. Obstacles in power transmission have not been eliminated. The power transmission line is still lack of power supply ability. In fact, right now all the transmission lines of the provisions of the static capacity allow for a wide margin. The transmission line load capacity is not fully utilized. Therefore, if we can make full use of the existing transmission lines in the power transmission capacity, transmission capacity will increase 20%-70%. Theory shows that domestic power carrying capacity can be largely enhanced by using DLR(Dynamic Line Rating),so that less power transmission lines as well as relevant equipments need be installed. The parameters related to transmission line is measured and reported by the DLR system developed in our laboratory. The data is analyzed by the background server to make some decisions. The DLR system can increase the capacity of the transmission line well and truly. This paper mainly study the calculate method of the increasing of the capacity of the transmission line and the design and application of the power supply system.In the first two part of this thesis, the recent domestic and overseas development of DLR technique was introduced. And then, the principle of DLR was expatiated, the proper parameters such as tension, temperature, wind speed, wind direction were measured to calculate the temperature, arc droop, current quantity carried by transmission line,also calculate formular and process were listed in detail. The tension-based method to measure the temperature of line is the first to be pointed out domestic. At the same time, different important parts of the DLR system such as data acquisition system, power supply system, communication flat roof, monitoring management flat roof were introduced separately.In the third part, different parts of the solar photovoltaic (PV) power supply system were described in characteristic and function in detail, and a series design and appilication methods were proposed to meet the need. For example, the maximum power point tracking (MPPT) was proposed to ensure the maximum output of PV array and the charge efficiency, battery grouping and the charge and discharge strategy was proposed to ensure the life of the battery pack, designed and realized the I2C line agreement which was used to communicate between the SCM of the power supply system and the SCM of the data acquisition system, the capacity of PV array and battery was selected according to the need of the power consumption of devices and the weather condition the devices was placed,some methods was proposed to resist disturb from the transmission line in ways of hardware and software, and was applied to the DLR system. The EMC test shows the good disturb resist ability of the DLR system.In the fourth part, the method of realizing the MPPT was studied, Perturb & Observe was proposed to realize the MPPT, and experiments were done to validate it, battery grouping and the charge and discharge strategy were proposed and realized, Battery grouping and the charge and discharge strategy was an innovation in the design of the power supply system. The operation results show that perturb & observe methods excellently realize the MPPT, improve the charging efficiency of the PV array, battery grouping and the charge and discharge management extend the life of battery pack.Finally, the works of studying and developing in DLR system were summarized, and something still need to be improved was proposed. The function of the system was realized though the cooperation of the companions in the laboratory and the equipment had run in some transmission line in the southern power grid company. The results show that the equipments function very well and totally met the application need. |
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