| Nowadays, mankind is undergoing an energy transformation and the pattern of primary energy from renewable energy and other clean energy-based will become reality. Due to the reason that China’s national economic and social development will remain at a faster ratefor a long period of timein the future, natural growth in electricity demand over the next30-40years will maintain a relatively fast growth rate. China’s power resources and load resources do not match geographically, especially as the reason that renewable energy can not be transported by an ordinary means of transport like fossil. Therefore, in the long run, a lot of "West to East, North to South" electricity will continue to be China’s national basic needs. Expected in2030-2050, there will be about500million kilowatts of electricity needs to send to eastfrom the west, a large number of long-distance transmission of electricity in the selection of the transmission channel is a big challenge.There may even be no suitable transmission corridor situation. To achieve this vision of the future grid, new transmission technology is needed.According to the continued growth of load demand and energy planning of Hubei power grid, the paper takes Hubei power grid absorptive outside area power supply as the background, researches the key problems of UHV access in Hubei power grid. The national grid planning of UHV backbone network and the "Twelfth Five Year Planning","Thirteen Five Year Planning" in Hubei power grid planning are also considered in this research. The main contents of the paper and the results are as follows.Considering the characteristics of AC and DC transmission technology, a comprehensive evaluation system of AC and DC transmission scheme considering power transmission characteristics, security and stability, economy and other factors is established and the preferred method of gray comprehensive AC and DC transmission scheme is proposed; each transmission scenarios under AC and DC transmission scheme established a comprehensive comparison, scope of application of different voltage levels of AC and DC transmission method is obtained.A set of UHV AC placement evaluation system is established, constructed UHV placement preferred decision matrix, using heavy weight index calculating method based on improved AHP method to obtain the optimal weight of each index weight, choosing the best placement of UHV AC, and simulation verification. Based on this, further according to the grid structure and system parameters of Hubei UHV after new placement involved, the limit of Hubei Grid consumption of high-voltage power electricity isstudied and calculated. A multi-infeed systems is established to assess HVDC evaluation system, determined the Hubei Grid "Thirteen Five" period Western Inner Mongolia HVDC access way. A long-term daily load function based on non-parametric regression model type curve prediction methods is proposed. Daily load of Hubei Power Grid "Thirteen Five" during a typical day in the curve is gotten. Based on this, as the background that wind power from West Inner Mongolia to Hubei UHV, established a mixed integer linear programming model of a thermal power, hydropower, pumped storage and optimizing UHV joint peaking, a coordinated peaking optimization program operation of UHV with thermal power, hydropower, pumped storage inHubei power grid is given.Aiming at the problem of the environmental friendliness of UHV landing in Hubei, starting from the noise prediction and governance, the outdoor substation overall noise attenuation prediction, multi point noise source equivalent modeling and passive noise reduction technology are studied. A three-dimensional UHV substation noise attenuation model is estabilished and a transformer equivalent source method for multi point based on the acoustic model is obtained. Based on the proposed modeling method, the problem of converter station/substation noise source modeling and spatial distribution of the sound field prediction problems are well solved. By analyzing the influencing factors on the transmission line frequency electric field measurements, the humidity is a major factor leading to power-frequency electric field measurement value larger, and the theoretical analysis of frequency electric field distribution of transmission lines below is carried on, demonstrating the humidity increases caused the main reason for changes in performance measurement instruments. |
