Technical development strategy of the hottest coun

Technical development strategy of county-level power construction

Abstract: according to the characteristics of long-distance power supply, scattered load and significant seasonal change of county-level power in China, aiming at the problems of county-level power, This paper puts forward the principles that should be followed in the county-level power transformation and the main technical measures that should be taken in the county-level power transformation and construction

key words: county-level power principles, technical measures, construction and development strategies Untitled Document. According to the characteristics of China's county-level power supply, such as long distance, scattered load, significant seasonal changes and so on, in view of the current problems of weak power structure, poor power quality, large line loss and low technical level of county-level power, This paper puts forward the principles that should be followed in the county-level power transformation and the main technical measures that should be taken in the county-level power transformation construction, and emphasizes that the construction of dispatching automation, distribution automation, substation automation and unattended substation should be mainly considered. On this basis, the demand of county-level electricity for automation is analyzed and discussed. At the same time, it is pointed out that there is a broad development prospect for county-level electricity to realize the utilization and replacement of high carbon spring steel in agricultural machinery equipment and accessories. 1. Characteristics of county-level electricity in China

according to the traditional concept, power distribution in China is divided into urban and rural areas. Relatively speaking, the urban power supply load is concentrated, and the power supply environment is good; Rural power supply has a large range, poor environment, long line radius, high accident probability and difficult to find. The county-level electricity, which manages the vast majority of farmers, is an important part of the power system and one of the important infrastructure for the construction of modern small towns

the main characteristics of county-level electricity are:

(1) long power supply distance, large distance between load points, and scattered distribution

(2) the load has obvious seasonal changes and is greatly affected by the natural environment and climate

(3) most of them are single power supply and radioactive structure, and most of the load points are "connected in series" by lines, with few electrical branches

(4) in addition to "series connection", the form of electrical load distribution is mainly "T-shaped connection. American company launched a new composite membrane regeneration technology to break the non renewable magic line (T-connection)" and "cross connection (T-connection in two directions at the same point)"

(5) the county has high power load density, concentrated power consumption and high requirements for power supply reliability, which has some characteristics of the city

2. The main problems existing in county-level electricity at present

in recent years, the residential and industrial power consumption in county-level electricity has increased rapidly, the power consumption structure has become increasingly reasonable, and the rural electrification rate, per capita power consumption and other indicators have been greatly improved. However, compared with urban electricity, county-level electricity still has the following problems:

(1) weak electrical structure. Most county-level electricity is radiated, the range of ring power supply is small, the load transfer capacity is poor, the range of accident and maintenance power outage is large, the reliability of power supply is low, there are many single main transformer and single circuit power supply areas, the transfer power supply capacity between substations is poor, the protection configuration is incomplete, and the safety level and automation level are very low, so the reliability of power supply is generally low, even lower than 99% in some areas. Since 1998, large-scale agricultural technology transformation and equipment renewal have been implemented, and some new distribution equipment such as vacuum or SF6 circuit breakers have been selected, which has played an important role in reducing line loss, improving voltage quality and improving rural power supply conditions. However, due to the limitation of funds, the new equipment is mainly used in substations, and there is not much change to the outdoor distribution lines with frequent accidents. 109 intelligent manufacturing pilot demonstration projects have been selected; Arrange 47 directions and 61 projects of industrial strong foundation projects. Due to the early erection time, many lines have problems such as long power supply radius, low technical level, serious aging of equipment, poor safety and reliability, large line loss, poor power quality, unreasonable layout, etc. some lines carry hundreds of transformers, and the load distribution is seriously unreasonable, which often leads to the power failure of the whole line due to the failure of one user. Line 2 The main motor source of the pipe ring stiffness tester has power, but the equipment cannot move up and down. The more roads cross, the more safe, economical and reliable operation of the distribution line will be affected. Most county-level electricity is lack of unified planning, so it still needs further construction and transformation

(2) low power quality and high line loss rate. In recent years, the county-level power load has increased rapidly. Due to the thin wires, few loops, insufficient distribution and transformation points, and lack of reactive power compensation capacity, the voltage qualification rate of the existing medium voltage distribution is generally low, most 10kV distribution is less than 96%, the qualification rate of low-voltage power is lower, and the line loss rate in some areas is as high as more than 10%

(3) the technical level is relatively backward, the equipment is still old, and the automation level is low. Although some new technologies and equipment have been applied in recent years, there is still a big gap compared with the city. The automation level of substation is not high, the dispatching automation is still imperfect, and the distribution automation is basically in the pilot stage

(4) the electricity price level is high. In recent years, through rural electricity transformation, rural electricity system reform and the implementation of the same price, the electricity price level of county-level electricity has been reduced. However, because the perfect rural power market has not been formed, and the electricity price formation mechanism that meets the requirements of market economy has not been established, compared with cities, the electricity price level at the county level is still high, which limits the rapid development of rural power market

(5) the level of rural electrification is still low. Since the reform and opening up, rural electrification has developed rapidly, and farmers' living standards have improved rapidly, but the per capita electricity consumption level is still at a low level. In 2002, China's per capita electricity consumption was 1239.6kw · h, and the per capita annual electricity consumption at and below the county level was 591.9kw · h, less than half of the national average; In terms of domestic power consumption, the per capita domestic power consumption of Chinese residents in 2002 was 169.1kw · h, of which 233.2kw · h was for urban residents and only 78.2kw · h was for rural residents, far behind the power consumption level of urban residents. In addition, there are many rural people in the old, young, border and poor areas who still do not have access to electricity

(6) the development of rural power market has not received widespread attention. At present, the national power system has formed a new situation of strengthening marketing and developing the power market. However, due to the restriction of the level of economic development in rural areas, more attention should be paid to the development of rural power market, so as to facilitate the rapid development of rural power market and promote the improvement of rural economy and farmers' living standards

3. Principles to be followed in the construction and transformation of county-level electricity

according to the relevant documents issued by the former Ministry of electric power and the requirements of the technical guidelines for the construction and transformation of county-level electricity in the national electricity company system recently issued by the national household appliance company, the following principles should be followed in the construction and transformation of county-level electricity:

(1) optimize the county-level electricity network structure, improve the safe operation level, enhance the ability to resist natural disasters and accidents, and improve the reliability of power supply

(2) improve the overall power supply energy of electricity