Analysis And Research On The Impact Of Action Of The Line Protection In 220kV Weak Feed System (Power)

Energy is the national body's blood, is one of the three pillars of modern society. First, the energy shortage will cause the operation difficult in automotive, aerospace, construction, petrochemical, transport of goods and agricultural and other economic areas. It is predicted that the demand for energy in the next decade will be doubled. As China's economic growth rate accelerated further, coal supply and demand of oil was tight, the country suffers a large scale of the power cuts, very tight supply of coal, oil imports surge, the insufficiently energy supply has become an important constraint on economic development. In the long run, energy issues will continue to be the most important issue with China's economic development. The using of coal, natural gas, oil and other fuels can produce large amounts of greenhouse gases, environmental pollution and ecological deterioration of the environment triggered by the use of conventional energy has caused widespread concern around the world, the worsening living environment will have a serious impact on the human economy, cultural and social activities.To ensure the security of energy supplies, improve the environment and promote sustainable economic and social development, from a long-term perspective to look at energy development strategy, China must seek a road that social, economic and environmental sustainable development, clean energy accounted for a large proportion of the energy supply and consumption. Considering the situation of renewable energy, development and utilization of renewable energy has its inevitability. In the long run, it can not only ease the development of energy-related environmental pollution and promote sustainable economic and social development, but also gradually improve China's coal-dominated energy consumption structure. Therefore, the development and utilization of renewable energy is the inevitable choice for China. As an inexhaustible supply of clean, renewable energy, the wind energy has drown increasing attention around the world.With the developing need for green energy in power system, more and more wind power plants have been added into the system. For example, wind power plants in Bao Tou of Innermongolia province always located in vast areas where are isolated and windy, such as Bai Yun and Da Mao districts in Bao Tou. The construction of wind power plants provides green energy for the system also making great contributions to the peak load regulating in these local grids. But as the construction of these local grids of which wind power plants set in are relatively backward, 220Kv lines in these areas are connected in a way of single supply with open loop instead of forming rings thus the method used in channel protection is a combination of fiber channel and high frequency channel. Before the accession of wind power, the simplicity and stability of high frequency channel can perfectly make up the drawbacks caused by fiber multiplex channel. But the connection of wind power makes the districts show a typical character of week feed system which forms a great test for system relay protection especially in high frequency protection of which one line can falsely trip two times. This article aims at analysising the mentioned two trips, the reasons of falsely trip in week feed system, working of first order system and the distribution and working of second order system in order to puts forward some improvements.