(I) analysis of future market development of cable and other equipment

According to the state grid corporation of China's power grid planning and 2020 vision goal report during the 11th five-year plan period, the state grid corporation of China will add a transmission line of 330 kv or above for 60,000 km, with a transformer capacity of 300 million kva and an investment of about 900 billion yuan. By 2010, the cross-region transmission capacity will reach more than 40 million kilowatts, and the transmission capacity will exceed 180 billion kilowatt-hours. State grid company during the period of "11th five-year plan" of the average investment is 180 billion yuan a year, given the southern power grid company investment in general for the state grid corporation of 1/3 ~ 1/4, state grid and southern grid investment sum would be likely to reach 225 billion yuan, compared with "15" the growth rate reached 90%, electrical equipment and power transmission and transformation equipment industry is faced with more bright prospects for development. Our consulting experts believe that the transformer industry in China has two main development directions: one is to develop to the direction of high voltage, ultra high voltage, especially 750 kv, 1100 kv. The second is to develop toward energy-saving and miniaturization. The former is mainly used in long-distance power transmission and transformation lines, while the latter is mainly used in urban power transmission and transformation lines. Distribution transformer market capacity is larger, but due to the lower technical barriers, many manufacturers, and small enterprise size, industry concentration is low, the market competition is still very fierce. But on the whole, the development opportunity of distribution transformer industry is greater than difficulty. China business information network expects demand for dry transformers in China to reach 50 million kVA by 2010.

Power capacity every year to more than 30 gw in our country, and the matching transformer multiples of new capacity of power generation capacity, it is generally believed 11 times in the past, now can be up to 13 times, even more than, that is to say, transformer production to more than 400 gva every year, according to the China electrical equipment industry association analysis, transformer is expected to complete 600 gva 2007, up 9% from a year earlier, in recent years, China's power grid construction and renovation fund every year, more than 100 billion yuan, In addition, the electrical equipment used in power station engineering, such as power plant power equipment, booster station equipment, protection and monitoring equipment, etc., generally accounts for 16% ~ 20% of the investment in power station equipment.

(ii) future market technology development direction of power transmission and distribution equipment

At present, the transmission and distribution system is facing some new problems. For example, it will be more and more restricted by environmental protection. Due to the possible electromagnetic interference, noise, electrostatic induction and landscape coordination problems of high-voltage and ultra-high-voltage transmission lines and substations, the construction land needed for new transmission lines and substations is also restricted. Due to the imbalance of energy distribution and economic development, large-capacity long-distance power transmission still has a strong momentum of development. The huge benefits of interconnection operation of power grid make the trend of interconnection of large power grid and interconnection of transnational power transmission also develop. In the global scope, it is gradually implementing the market-oriented reform of power system, and power users have higher and higher requirements on power quality (preventing flicker, reducing harmonic, etc.).

This requires that the transmission and distribution system has good environmental performance, high reliability, high power quality and flexible control of power flow, etc., and that the transmission and distribution equipment can adapt to the new characteristics of the future power system and meet the new requirements of the power system. The development trend of transmission and distribution technology is roughly as follows:

In order to realize long-distance and large-capacity transmission, the voltage level of ac transmission has been gradually improved. In the late 1960s, the voltage of ac transmission has been increased to 735kV, 765kV and 800kV. Many countries have built 345kV, 400kV, 500kV, 750kV and 800kV power grids.

2. HVDC transmission technology develops rapidly. The main advantages of HVDC technology are: it is suitable for long-distance transmission without increasing the short-circuit capacity of the system; It is convenient to realize the non-synchronous networking operation of two power systems and the networking of power systems with different frequencies. Using the power modulation of dc system can improve the damping of power system, suppress the low-frequency oscillation and improve the transmission capacity of ac transmission lines running side by side.

The cost of HVDC transmission line is lower than that of ac transmission line, but the cost of converter station is much higher than that of ac substation. It is generally believed that the overhead line exceeds 600-800km, the cable line exceeds 40-60km, and the dc transmission is more economical than the ac transmission. With the development of high voltage and large capacity thyristor and control and protection technology, the cost of converter equipment is gradually reduced, and dc transmission has developed rapidly in recent years.

From the 11th five-year plan to 2020, China plans to build more than 10 HVDC transmission projects. In foreign countries, two-terminal HVDC transmission is a relatively mature technology. Moreover, multi-terminal HVDC transmission technology has been developed, and now three-terminal HVDC has been operated in Canada. There is also the development of light HVDC transmission, which has been studied and applied abroad (ABB company called HVDCLight, Siemens company called HVDCPlus). Light HVDC transmission system, which USES GTO, IGBT and other switchable components to form a converter, eliminating the converter transformer, the entire converter station can be relocated, so that medium capacity HVDC projects in a shorter transmission distance can also compete with ac transmission. In addition, it can be shut off device of converter, as a result of what use can be shut off the power electronic devices, can avoid the commutation failure problem, for the end system capacity did not demand, so it can be used to isolate the system (power supply) of offshore oil platform, island, in the future can also be used for urban power distribution system, and is used to access the fuel cell, photovoltaic power generation (PhotovoltaicPowerGeneration) distributed power supply.

At present, domestic VHVDC converter station equipment is mainly provided by ABB and Siemens, while domestic xd and other companies have introduced technology and carried out localization. More and more HVDC transmission lines have been built, which requires the localization of HVDC equipment to be accelerated.

3. FACTS about flexible ac transmission system technology

Flexible ac transmission technology (also known as flexible ac transmission technology) is a kind of transmission technology based on power electronics technology and modern control technology, which can flexibly and quickly adjust the impedance, voltage and phase of ac transmission system and improve the controllability, transmission capacity and stability of ac transmission system.

Flexible ac transmission system technology (FACTS) is a product of the "second silicon revolution" of power system control technology. The need of power grid development and large-scale interconnected power grid operation for power system power flow and stability control, together with the progress of power electronics technology, has greatly promoted the development and application of a new transmission technology -- flexible ac transmission system technology.

4. Compact transmission technology: compact transmission technology can reduce the phase distance and change the arrangement of transmission lines, so as to reduce the line reactance and increase the capacitance reactance, and increase the rated natural power under the condition that the rated voltage of the line remains unchanged. In 1999 China's north China built a 500 kv transmission line compact test (changping - well) is 85 km long, conductor adopted six division structure (e.g., 6 x240mmz), the diameter of the circle is 750 mm, and USES the nabla arrangement, and distance of 6.7 m, 10 m, lead to ground distance corridor width 16 m, natural power is 1/3 higher than conventional lines, compact transmission lines shall be installed at the appropriate location of line shunt reactor, and the capacity of the reactor should be controlled, so it can vary according to the load of the line system of reactive power current to achieve dynamic balance, Ensure the dynamic stability of the power grid. The controllable reactor used in this kind of compact transmission line is a key equipment which needs independent production.

5. Large-capacity transmission and distribution equipment

Large-capacity transmission and distribution equipment mainly includes: large-capacity transformer refers to the transformer of 500kV, l000MVA or above, which is mainly used to adapt to the power supply needs of the large-load center and save the land used by the substation. At present, such large-capacity transformer of 500kV and 1000MVA has been successively adopted in the load-intensive east China and nanjing power grid. Large section cable, such as 220kV, 2500mm2 power cable; Development and application of large section overhead conductor and large section heat-resistant conductor above 2x630m. Mz. The manufacture of circuit breakers with breaking capacity of 63kA and above.

6. Gas insulated transmission line (GIL)

The transmission capacity of SF6 gas-insulated transmission line is larger than that of cable transmission line, which can be laid on the ground and underground, and the cost is lower than that of cable line. At present, some major transmission and distribution manufacturers in the world have developed gas-insulated transmission lines.

7. HTS transmission has a promising future

The U.S. department of energy and southern wire have partnered on a high-temperature superconductor project for a 100ft(LFT =0.3048m), three-phase power cable system. The next ten years will be a decade of market development and material industrialization for HTS (including generators, transformers, motors, cables, etc.). It is predicted that the world superconductor market will reach $30 billion/year in 2010 and $244 billion/year in 2020.

8. Highly integrated, compact and intelligent transmission and distribution equipment

The most representative type of compact power transmission and distribution equipment is the gas insulated switch equipment (GIS) used in the high-voltage and ultra-high-voltage systems, the open combination switch equipment, and the inflatable cabinet (c-gis) and inflatable ring network cabinet used in the medium-voltage system. In order to meet the need of the development of modern substation miniaturization and automation, has been to a device (such as circuit breakers, isolating switch, grounding switch, current and voltage transformer, lightning arrester, etc.) and the second device (intelligent protection, measurement and monitoring system) together with high integration, compact power transmission and distribution equipment, such as ABB PASS system, Siemens HIS system, etc. A high-voltage generator using cable-wound (stator) has been developed abroad (it is called Powerformer in foreign countries, the output voltage of this generator is 132kV or higher, and the output voltage of the conventional large-capacity generator is 20kV). In this way, the power can be sent out without the need of booster transformer, which greatly simplifies the booster station of the power plant. Uhvdc converter station equipment and flexible ac transmission equipment are also perfect integration of high voltage, uhv and large capacity power conversion, control and digital monitoring technology. In the automatic monitoring system of modern power system, each transmission and distribution equipment at the equipment level will become the terminal equipment of the computer monitoring system to realize the information exchange with the interval layer, station control layer and network management layer of the substation. High reliability, maintenance-free, intelligent, communicable, on-line monitoring and remote fault diagnosis of transmission and distribution equipment will be the development trend.

9. New flexible and reliable intelligent power distribution system

The future power distribution system can provide multi-quality "flexible", "reliable", "agile" and "perfect" power services according to the needs of different users. Users are also free to choose the quality, type and supplier of electricity. The system has perfect distributed power supply and energy storage system to ensure uninterrupted power supply. Perfect demand side management and real-time two-way transmission of information and so on. At present, distribution management automation system (DMS) is a rapidly developing field, including distribution system SCADA, load control, fault automatic isolation, reactive power automatic compensation, power management and equipment management.

10. Pay attention to the environmental performance of transmission and distribution equipment

We should pay attention to the environmental performance of the products, especially to reduce the use of SF6 gas (because SF6 gas will produce greenhouse effect), foreign countries have begun to use nitrogen, part of nitrogen and part of SF6 gas mixture to replace SF6 gas and other programs. Contacts such as contactors do not use silver pick alloy (that is, silver oxide pick, AgCdO, now foreign has been replaced by silver oxide tin, AgSnO2) and other problems. About discarded electrical and electronic equipment (instruction) and on the limit the use of certain hazardous substances in electrical and electronic equipment directive) clear requirements from July 1, 2006 to ensure that the market of new electronic and electrical equipment does not include lead, mercury, picks, hexavalent chromium, Macao diphenyl biphenyls (PBB) and Australia (PBDE) six kinds of harmful substances. Therefore, in the low voltage apparatus and relay contactor material containing kam, such as silver, will be gradually by excluding picks component contact.