(I) Analysis of future market development of cable and other equipment
According to the State Grid Corporation's "11th Five-Year Plan" period of power network planning and 2020 vision report, during the "Eleventh Five-Year Plan" period, the State Grid Corporation of China will add 60,000 kV and above transmission lines to 60,000 kilometers, with 300 million kilovolts of transformer capacity. Anh, the investment is about 900 billion yuan. By 2010, the trans-regional transmission capacity will reach more than 40 million kilowatts, and the transmission of electricity will exceed 180 billion kilowatt-hours. During the “Eleventh Five-Year Plan†period, the State Grid Corporation invested an average of 180 billion yuan each year, taking into account that China Southern Power Grid Corporation’s investment is generally 1/3 to 1/4 of that of the State Grid Corporation, and the total investment of the State Grid and China Southern Power Grid may reach 225 billion yuan. Compared with the “10th Five-year Planâ€, the increase rate has reached 90%, and the electrical equipment and power transmission and transformation equipment industry are facing brighter development prospects. Our consulting experts believe that China's transformer industry has two main directions of development: First, it is developing in the direction of high pressure and ultra high voltage, especially 750 kV and 1100 kV. The second is the development of energy-saving and miniaturization. The former is mainly applied to long-distance power transmission and transmission lines, and the latter is mainly used in urban power transmission and transmission lines. The market capacity of distribution transformers is relatively large, but due to low technical barriers, numerous manufacturers, and small enterprises, the industry concentration is low, and market competition is still fierce. But overall, the development opportunities in the distribution transformer industry are greater than the difficulties. China Business Intelligence Network expects that by 2010, the demand for dry-type transformers in China will reach 50 million kVA.
China's annual installed power generation capacity exceeds 30 GW, and the corresponding new transformer capacity is a multiple of the power generation capacity. In the past, it was generally considered as 11 times, now it can reach 13 times, and even exceeds, that is to say, the annual output of transformers is required. More than 400GVA, according to the analysis of China Electrical Equipment Industry Association, transformers are expected to complete 600GVA in 2007, an increase of 9% year-on-year. In recent years, China's power grid construction and reconstruction funds have exceeded 100 billion yuan each year, plus the use of electrical equipment in power plant projects. Electric equipment, booster station equipment, protection and monitoring equipment generally account for 16% to 20% of investment in power station equipment.
(II) Development direction of future market technology for power transmission and distribution equipment
At present, the transmission and distribution system is facing some new problems, such as the degree of environmental restrictions will be greater and greater, due to electromagnetic interference, noise, electrostatic induction and landscape coordination issues such as high-voltage, ultra-high voltage transmission lines and substations, new transmission The construction land required for lines and substations is also limited; due to the imbalance of energy distribution and economic development, large-capacity long-distance power transmission still has a relatively strong development momentum; the huge benefits of grid interconnection operation enable large-scale power grid interconnection and multinational networking transmission. The trend is also developing; in the global scope, the reform of the marketization of power systems is being gradually implemented and power users are demanding higher and higher power quality (anti-flicker and harmonic reduction).
This requires the transmission and distribution system to have good environmental performance, high reliability, high power quality, and flexible control of the trend, and requires the transmission and distribution equipment to adapt to the new characteristics of the future power system and meet the new requirements of the power system. . The development trend of power transmission and distribution technology is roughly:
1. In order to realize long-distance and high-volume AC transmission, the voltage level of AC transmission gradually increases. At the end of the 1960s, the AC transmission voltage has been increased to 735kV, 765kV and 800kV, and 345kV has been built in many countries. , 400kV, 500kV, 750kV, 800kV power grid.
2. The HVDC transmission technology has developed rapidly. The main advantages of HVDC transmission technology are: It is suitable for long-distance transmission without increasing the short-circuit capacity of the system; it is convenient for the non-synchronous networked operation of two large power systems and the networking of power systems with different frequencies; Using the power modulation of the DC system can improve the damping of the power system, suppress the low-frequency oscillation, and increase the transmission capacity of the AC power transmission lines running in parallel.
The cost of DC transmission lines is lower than that of AC transmission lines, but the cost of converter stations is much higher than that of AC substations. It is generally believed that overhead lines exceed 600-800 km and cable lines exceed 40-60 km. DC transmission is more economical than AC transmission. With the development of high-voltage and large-capacity thyristors and control and protection technologies, the cost of converter equipment has gradually decreased, and DC transmission has developed rapidly in recent years.
From the “Eleventh Five-Year Plan†to 2020, there are more than 10 HVDC projects planned to be built in China. The DC transmission at both ends of the country is already a mature technology. Moreover, multi-end DC transmission technology has been researched. Now, three-terminal DC transmission has been operating in Canada. Light-duty DC transmission is also under development, and light DC transmission has been researched and applied abroad (ABB called HVDCLight, and Siemens called HVDCPlus). Light-duty DC transmission system, which uses components such as GTO and IGBT that can be turned off to form a converter, eliminating the need for a converter transformer and allowing the entire converter station to be relocated, enabling medium-capacity HVDC transmission projects to be operated at shorter distances. Can compete with AC transmission. In addition, the devices that can be turned off compose the inverter. Since the power electronics can be turned off, the problem of commutation failure can be eliminated, and there is no requirement for the capacity of the receiver system, so it can be used for isolated small systems (offshore oil platforms). Power supply for islands and islands can be used in the future for urban power distribution systems and for access to distributed power sources such as fuel cells, photovoltaic power generation (Photovoltaic Power Generation).
At present, the domestic UHV DC transmission project converter station equipment is mainly provided by ABB and Siemens, domestic companies such as Western Electric have been introducing technology for localization. The number of newly-built DC transmission lines is now relatively large, which also requires the acceleration of the localization of HVDC transmission equipment.
3. About Flexible AC Transmission System Technology (FACTS)
About flexible AC transmission technology (also known as flexible AC transmission technology) is based on power electronic technology and modern control technology on the AC transmission system impedance, voltage, phase implementation of flexible and rapid adjustment of transmission technology, can improve the AC transmission system controllability, Transmission capacity and stability.
The Flexible AC Transmission System Technology (FACTS) is known as a product of the "second silicon revolution" of power system control technology. The development of power grids and the need for large-scale interconnected power grids to control the power system's power flow and its stability, coupled with advances in power electronics technology, has greatly advanced the development and application of new transmission technologies—flexible AC transmission system technologies.
4. Compact transmission technology. The compact transmission technology reduces the phase distance between transmission lines and changes the arrangement, thereby reducing the line reactance, increasing capacitive reactance, and increasing the rated natural power under the condition that the line rated voltage is constant. A more economical transmission technology that improves the UHV AC transmission capability. In 1999, a 500 kV compact test transmission line (Changping--Fangshan) was built in North China in China and was 85 km long. The sub-conductor was a six-split structure (such as 6x240 mmz), and the diameter of the ring was 750 mm. The phase sequence was inverted triangle and the distance between phases was 6.7 m. The distance between the conductor and the ground is 10m, and the corridor width is 16m. The natural power is increased by 1/3 compared to the conventional line. The compact transmission line should be installed with shunt reactors at appropriate positions on the line, and the capacity of the reactor should be controlled so that it can be based on The load changes of the line make the reactive power flow of the system achieve dynamic balance and ensure the dynamic stability of the power grid. The controllable reactors used in such compact transmission lines are the key equipments that need to be autonomously produced.
5. Large-capacity power transmission and distribution equipment
Large-capacity power transmission and distribution equipment mainly includes: Large-capacity transformers are 500kV, l000MVA or more transformers, mainly to meet the needs of large-load central power supply, saving the land used by substations, currently used in China's load-intensive East China and Nanjing power grids. This 500kV, 1000MVA large capacity transformer. Large-section cable, such as 220kV, 2500mm2 power cable; 2x630m.mz above the large-area overhead wire and large cross-section heat-resistant wire development and application. Breakage capacity is 63kA and above circuit breaker manufacturing.
6. Gas insulated transmission lines (GIL)
The transmission capacity of SF6 gas insulated transmission lines is greater than the cable transmission lines, which can be laid on the ground and underground, and the cost is lower than the cable line. At present, some major transmission and distribution manufacturers in the world have developed gas-insulated transmission lines.
7. High-temperature superconducting power transmission has a bright future
A high-temperature superconducting project that the U.S. Department of Energy and Southern Wire Corporation cooperated with was a 100-ft (lft=0.3048m) 3-phase power cable system. The next decade is a decade of market development and material industrialization of high-temperature superconductors (including generators, transformers, motors, cables, etc.). It is predicted that in 2010 and 2020, the world superconducting market will reach US$30 billion/year and US$244 billion/year, respectively.
8. Highly-integrated, compact, and intelligent power transmission and distribution equipment
The most representative of the compact power transmission and distribution equipment is the gas-insulated switchgear (GIS) used in high-voltage and ultra-high-pressure systems, open-type combined switchgear, and the inflator (C-GIS) used in medium-voltage systems. Inflatable ring network cabinets. In order to meet the needs of the modernization of substations for miniaturization and automation, primary equipment (such as circuit breakers, disconnectors, earthing switches, current and voltage transformers, surge arresters, etc.) and secondary equipment (intelligent protection, measurement, and High-integration, compact power transmission and distribution equipment, such as ABB's PASS system and Siemens' HIS system. It has been developed abroad as a high-voltage generator using a cable-winding (stator) (known abroad as the Powerformer, whose output voltage is 132kV or higher, and the conventional large-capacity generator has an output voltage of 20kV). Power can be delivered without a step-up transformer, greatly simplifying the power station's boost station. The converter station equipment and flexible AC transmission equipment for UHVDC transmission are also the perfect integration of high-voltage, ultra-high-voltage large-capacity power conversion, control and digital monitoring technologies. In the modern power system's automatic monitoring system, each power transmission and distribution device at the equipment level will become the terminal equipment of the computer monitoring system, and realize the information exchange with the substation's bay level, station control layer and network management layer. The high reliability, maintenance-free, intelligent, communicable, on-line monitoring and remote fault diagnosis of power transmission and distribution equipment will be the trend.
9. New type of flexible and reliable intelligent power distribution system
The future distribution system can provide multi-quality "flexible", "reliable", "agile" and "perfect" electrical energy services according to the needs of different users; users can also freely choose the quality, types and suppliers of electricity. . The system has a perfect distributed power supply and energy storage system to ensure uninterrupted power supply; perfect demand side management and real-time bidirectional transmission of information and so on. The current distribution management automation system (DMS) is a very fast-growing area, including the SCADA of power distribution systems, load control, automatic fault isolation, automatic reactive compensation, power consumption management, and equipment management.
10. Pay attention to the environmental performance of power transmission and distribution equipment
We must pay attention to the environmental performance of our products, and we must pay particular attention to using less SF6 gas (because SF6 gas will produce a greenhouse effect). Foreign countries have begun to use nitrogen, some nitrogen, and some SF6 gas mixtures instead of SF6 gas. Contactors and other contacts do not use silver niobium alloys (ie, silver niobium oxide, AgCdO, silver tin oxide has been used abroad, AgSnO2 instead) and other issues. The "Regarding Waste Electrical and Electronic Equipment Directive" and the "Restriction on the Use of Certain Hazardous Substances in Electrical and Electronic Equipment" clearly require that starting from July 1, 2006, new electronic and electrical equipment placed on the market should not include lead, mercury, Hexavalent chromium, hexavalent chromium, polyphenylene oxide (PBB) and polyphenylene oxide (PBDE) are six harmful substances. Therefore, in the contact materials of low-voltage electrical appliances and relays, if the use of brocade, such as silver oxidized blessing, should gradually adopt the contact without helium component.
According to the State Grid Corporation's "11th Five-Year Plan" period of power network planning and 2020 vision report, during the "Eleventh Five-Year Plan" period, the State Grid Corporation of China will add 60,000 kV and above transmission lines to 60,000 kilometers, with 300 million kilovolts of transformer capacity. Anh, the investment is about 900 billion yuan. By 2010, the trans-regional transmission capacity will reach more than 40 million kilowatts, and the transmission of electricity will exceed 180 billion kilowatt-hours. During the “Eleventh Five-Year Plan†period, the State Grid Corporation invested an average of 180 billion yuan each year, taking into account that China Southern Power Grid Corporation’s investment is generally 1/3 to 1/4 of that of the State Grid Corporation, and the total investment of the State Grid and China Southern Power Grid may reach 225 billion yuan. Compared with the “10th Five-year Planâ€, the increase rate has reached 90%, and the electrical equipment and power transmission and transformation equipment industry are facing brighter development prospects. Our consulting experts believe that China's transformer industry has two main directions of development: First, it is developing in the direction of high pressure and ultra high voltage, especially 750 kV and 1100 kV. The second is the development of energy-saving and miniaturization. The former is mainly applied to long-distance power transmission and transmission lines, and the latter is mainly used in urban power transmission and transmission lines. The market capacity of distribution transformers is relatively large, but due to low technical barriers, numerous manufacturers, and small enterprises, the industry concentration is low, and market competition is still fierce. But overall, the development opportunities in the distribution transformer industry are greater than the difficulties. China Business Intelligence Network expects that by 2010, the demand for dry-type transformers in China will reach 50 million kVA.
China's annual installed power generation capacity exceeds 30 GW, and the corresponding new transformer capacity is a multiple of the power generation capacity. In the past, it was generally considered as 11 times, now it can reach 13 times, and even exceeds, that is to say, the annual output of transformers is required. More than 400GVA, according to the analysis of China Electrical Equipment Industry Association, transformers are expected to complete 600GVA in 2007, an increase of 9% year-on-year. In recent years, China's power grid construction and reconstruction funds have exceeded 100 billion yuan each year, plus the use of electrical equipment in power plant projects. Electric equipment, booster station equipment, protection and monitoring equipment generally account for 16% to 20% of investment in power station equipment.
(II) Development direction of future market technology for power transmission and distribution equipment
At present, the transmission and distribution system is facing some new problems, such as the degree of environmental restrictions will be greater and greater, due to electromagnetic interference, noise, electrostatic induction and landscape coordination issues such as high-voltage, ultra-high voltage transmission lines and substations, new transmission The construction land required for lines and substations is also limited; due to the imbalance of energy distribution and economic development, large-capacity long-distance power transmission still has a relatively strong development momentum; the huge benefits of grid interconnection operation enable large-scale power grid interconnection and multinational networking transmission. The trend is also developing; in the global scope, the reform of the marketization of power systems is being gradually implemented and power users are demanding higher and higher power quality (anti-flicker and harmonic reduction).
This requires the transmission and distribution system to have good environmental performance, high reliability, high power quality, and flexible control of the trend, and requires the transmission and distribution equipment to adapt to the new characteristics of the future power system and meet the new requirements of the power system. . The development trend of power transmission and distribution technology is roughly:
1. In order to realize long-distance and high-volume AC transmission, the voltage level of AC transmission gradually increases. At the end of the 1960s, the AC transmission voltage has been increased to 735kV, 765kV and 800kV, and 345kV has been built in many countries. , 400kV, 500kV, 750kV, 800kV power grid.
2. The HVDC transmission technology has developed rapidly. The main advantages of HVDC transmission technology are: It is suitable for long-distance transmission without increasing the short-circuit capacity of the system; it is convenient for the non-synchronous networked operation of two large power systems and the networking of power systems with different frequencies; Using the power modulation of the DC system can improve the damping of the power system, suppress the low-frequency oscillation, and increase the transmission capacity of the AC power transmission lines running in parallel.
The cost of DC transmission lines is lower than that of AC transmission lines, but the cost of converter stations is much higher than that of AC substations. It is generally believed that overhead lines exceed 600-800 km and cable lines exceed 40-60 km. DC transmission is more economical than AC transmission. With the development of high-voltage and large-capacity thyristors and control and protection technologies, the cost of converter equipment has gradually decreased, and DC transmission has developed rapidly in recent years.
From the “Eleventh Five-Year Plan†to 2020, there are more than 10 HVDC projects planned to be built in China. The DC transmission at both ends of the country is already a mature technology. Moreover, multi-end DC transmission technology has been researched. Now, three-terminal DC transmission has been operating in Canada. Light-duty DC transmission is also under development, and light DC transmission has been researched and applied abroad (ABB called HVDCLight, and Siemens called HVDCPlus). Light-duty DC transmission system, which uses components such as GTO and IGBT that can be turned off to form a converter, eliminating the need for a converter transformer and allowing the entire converter station to be relocated, enabling medium-capacity HVDC transmission projects to be operated at shorter distances. Can compete with AC transmission. In addition, the devices that can be turned off compose the inverter. Since the power electronics can be turned off, the problem of commutation failure can be eliminated, and there is no requirement for the capacity of the receiver system, so it can be used for isolated small systems (offshore oil platforms). Power supply for islands and islands can be used in the future for urban power distribution systems and for access to distributed power sources such as fuel cells, photovoltaic power generation (Photovoltaic Power Generation).
At present, the domestic UHV DC transmission project converter station equipment is mainly provided by ABB and Siemens, domestic companies such as Western Electric have been introducing technology for localization. The number of newly-built DC transmission lines is now relatively large, which also requires the acceleration of the localization of HVDC transmission equipment.
3. About Flexible AC Transmission System Technology (FACTS)
About flexible AC transmission technology (also known as flexible AC transmission technology) is based on power electronic technology and modern control technology on the AC transmission system impedance, voltage, phase implementation of flexible and rapid adjustment of transmission technology, can improve the AC transmission system controllability, Transmission capacity and stability.
The Flexible AC Transmission System Technology (FACTS) is known as a product of the "second silicon revolution" of power system control technology. The development of power grids and the need for large-scale interconnected power grids to control the power system's power flow and its stability, coupled with advances in power electronics technology, has greatly advanced the development and application of new transmission technologies—flexible AC transmission system technologies.
4. Compact transmission technology. The compact transmission technology reduces the phase distance between transmission lines and changes the arrangement, thereby reducing the line reactance, increasing capacitive reactance, and increasing the rated natural power under the condition that the line rated voltage is constant. A more economical transmission technology that improves the UHV AC transmission capability. In 1999, a 500 kV compact test transmission line (Changping--Fangshan) was built in North China in China and was 85 km long. The sub-conductor was a six-split structure (such as 6x240 mmz), and the diameter of the ring was 750 mm. The phase sequence was inverted triangle and the distance between phases was 6.7 m. The distance between the conductor and the ground is 10m, and the corridor width is 16m. The natural power is increased by 1/3 compared to the conventional line. The compact transmission line should be installed with shunt reactors at appropriate positions on the line, and the capacity of the reactor should be controlled so that it can be based on The load changes of the line make the reactive power flow of the system achieve dynamic balance and ensure the dynamic stability of the power grid. The controllable reactors used in such compact transmission lines are the key equipments that need to be autonomously produced.
5. Large-capacity power transmission and distribution equipment
Large-capacity power transmission and distribution equipment mainly includes: Large-capacity transformers are 500kV, l000MVA or more transformers, mainly to meet the needs of large-load central power supply, saving the land used by substations, currently used in China's load-intensive East China and Nanjing power grids. This 500kV, 1000MVA large capacity transformer. Large-section cable, such as 220kV, 2500mm2 power cable; 2x630m.mz above the large-area overhead wire and large cross-section heat-resistant wire development and application. Breakage capacity is 63kA and above circuit breaker manufacturing.
6. Gas insulated transmission lines (GIL)
The transmission capacity of SF6 gas insulated transmission lines is greater than the cable transmission lines, which can be laid on the ground and underground, and the cost is lower than the cable line. At present, some major transmission and distribution manufacturers in the world have developed gas-insulated transmission lines.
7. High-temperature superconducting power transmission has a bright future
A high-temperature superconducting project that the U.S. Department of Energy and Southern Wire Corporation cooperated with was a 100-ft (lft=0.3048m) 3-phase power cable system. The next decade is a decade of market development and material industrialization of high-temperature superconductors (including generators, transformers, motors, cables, etc.). It is predicted that in 2010 and 2020, the world superconducting market will reach US$30 billion/year and US$244 billion/year, respectively.
8. Highly-integrated, compact, and intelligent power transmission and distribution equipment
The most representative of the compact power transmission and distribution equipment is the gas-insulated switchgear (GIS) used in high-voltage and ultra-high-pressure systems, open-type combined switchgear, and the inflator (C-GIS) used in medium-voltage systems. Inflatable ring network cabinets. In order to meet the needs of the modernization of substations for miniaturization and automation, primary equipment (such as circuit breakers, disconnectors, earthing switches, current and voltage transformers, surge arresters, etc.) and secondary equipment (intelligent protection, measurement, and High-integration, compact power transmission and distribution equipment, such as ABB's PASS system and Siemens' HIS system. It has been developed abroad as a high-voltage generator using a cable-winding (stator) (known abroad as the Powerformer, whose output voltage is 132kV or higher, and the conventional large-capacity generator has an output voltage of 20kV). Power can be delivered without a step-up transformer, greatly simplifying the power station's boost station. The converter station equipment and flexible AC transmission equipment for UHVDC transmission are also the perfect integration of high-voltage, ultra-high-voltage large-capacity power conversion, control and digital monitoring technologies. In the modern power system's automatic monitoring system, each power transmission and distribution device at the equipment level will become the terminal equipment of the computer monitoring system, and realize the information exchange with the substation's bay level, station control layer and network management layer. The high reliability, maintenance-free, intelligent, communicable, on-line monitoring and remote fault diagnosis of power transmission and distribution equipment will be the trend.
9. New type of flexible and reliable intelligent power distribution system
The future distribution system can provide multi-quality "flexible", "reliable", "agile" and "perfect" electrical energy services according to the needs of different users; users can also freely choose the quality, types and suppliers of electricity. . The system has a perfect distributed power supply and energy storage system to ensure uninterrupted power supply; perfect demand side management and real-time bidirectional transmission of information and so on. The current distribution management automation system (DMS) is a very fast-growing area, including the SCADA of power distribution systems, load control, automatic fault isolation, automatic reactive compensation, power consumption management, and equipment management.
10. Pay attention to the environmental performance of power transmission and distribution equipment
We must pay attention to the environmental performance of our products, and we must pay particular attention to using less SF6 gas (because SF6 gas will produce a greenhouse effect). Foreign countries have begun to use nitrogen, some nitrogen, and some SF6 gas mixtures instead of SF6 gas. Contactors and other contacts do not use silver niobium alloys (ie, silver niobium oxide, AgCdO, silver tin oxide has been used abroad, AgSnO2 instead) and other issues. The "Regarding Waste Electrical and Electronic Equipment Directive" and the "Restriction on the Use of Certain Hazardous Substances in Electrical and Electronic Equipment" clearly require that starting from July 1, 2006, new electronic and electrical equipment placed on the market should not include lead, mercury, Hexavalent chromium, hexavalent chromium, polyphenylene oxide (PBB) and polyphenylene oxide (PBDE) are six harmful substances. Therefore, in the contact materials of low-voltage electrical appliances and relays, if the use of brocade, such as silver oxidized blessing, should gradually adopt the contact without helium component.
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