The “2012-2016 China High-voltage Switching Industry Investment Strategy and In-Depth Research Consultation Report†shows that it is recommended that during the “Twelfth Five-Year Plan†period, large-scale key enterprises in the high-voltage switch industry should further develop technical studies on the core technologies and key components of UHV switchgear. To achieve the goal of UHV equipment based on domestic, independent research and development, and fully realize localization. Combining the construction of smart grids, digital substations, and distribution automation, we will vigorously promote the intelligentization of switchgear. Since the intelligent technology of switchgear is still a weak point in the industry, it is recommended that it be developed first and then easily. For example: firstly develop intelligent circuit breakers for distribution networks, and then develop switchgear for intelligent distribution networks, smart grid GIS, GCB and others. Smart components, etc., focus on the overall integration of switch primary equipment and secondary control and the development of interface technologies. Actively carry out research in the field of switch simulation technology, 126-252kV GIS reliability theory system research, voltage, current sensing technology and power equipment online monitoring technology research. Increase the research and development efforts of energy-saving and environmental protection, high reliability and low (free) maintenance of switchgear. Strengthen miniaturization, large capacity, total box technology and product development. Actively develop the development of switches for special occasions, special switchgear and renewable energy generation (such as wind power). Efforts are made to develop research and development with forward-looking and directional technologies and equipment (such as high-voltage bypass switches, superconducting switches, etc.). Continue to carry out research on UHV power transmission projects, focusing on the construction of ±800kV UHV DC projects, conduct in-depth research on key technical issues in system research and complete sets of equipment, and carry out key issues involved in the pre-feasibility study of ±1000kV DC projects. The research focuses on the research and development of key technologies involved in the complete sets of UHV DC projects and double HVDC power transmission engineering systems on the same tower; continuing the research on the exchange of flexible transmission engineering systems and complete sets of technologies; and relying on projects to continue to work closely with power grid companies to develop Super, UHV DC project construction. At the same time, in the field of testing and testing technologies, the industry continues to conduct research on test and inspection technologies to further expand its testing service business. The focus is to further improve and upgrade the test and detection technologies of AC and DC UHV equipment; carry out large-scale generator short-circuit test methods, ±800kV DC converter valve operation test technology, UHV DC converter valve insulation test technology, and special environment test technology, High-voltage electrical equipment seismic performance test technology, switchgear reliability test technology, intelligent power equipment test technology research.
Research Institute of China Polytech Industries believes that China's distribution switch control equipment industry is in an unprecedented boom. In the eight years since 2003, the compound annual growth rate of sales revenue of the industry has reached 30%, and the momentum of development has been rapid. With the continuous growth of power grid construction investment projects, as well as the increasing demand for railway electrification and urban rail transit construction, the industry will usher in a broader market. At the same time, the competitiveness of domestic companies has risen rapidly, gradually breaking the situation in which foreign brands such as ABB and Siemens dominate the market. State-owned and private enterprises have competed with foreign brands on the same stage. Statistical data analysis shows that China’s power grid investment has grown rapidly since 2003, with a compound annual growth rate of 25%. Despite this, it still cannot solve the problem of inadequate transmission capacity of the power grid. The investment in urban rail transit infrastructure construction also shows an upward trend. According to market research, six cities, including Beijing and Shanghai, are planning or planning to expand the existing subway network. In addition, there are 25 cities planning to develop urban rail transit. According to the calculation of the demand for high and low voltage switchgear for the Guangzhou Metro Line 3, 46 to 50 sets of low-voltage switchgear equipment are required on an average per kilometer subway line, requiring 15 C-GIS units. Based on this calculation, before 2015, rail transit will require 75,000 low-voltage switchgears and 22,500 C-GISs. In addition, the construction of large-scale projects such as the West-East Gas Pipeline, the South-to-North Water Transfer Project, and airports will also provide a large market space for the distribution switch control equipment industry.
The “Twelfth Five-Year Plan†two-network company plans to complete 571.6 billion yuan of rural network transformation investment projects, an increase of 51.78% over the “Eleventh Five-Year Planâ€. In addition to the rural network, the investment in the urban network transformation of the two networks has continued, thus providing demand support for distribution switchgear. The technology level of domestic-funded enterprises' mature products has been quite similar to that of foreign brands and the cost performance is high. If the investment funds are tight, the cost-effectiveness advantage of domestic brands will gradually emerge, and the cakes of foreign brands will gradually be devoured. State Grid Corporation of China and other large users gradually adopt centralized bidding methods for distribution switches. SMEs that lack a competitive advantage are gradually marginalized. With the advancement of separation of main and auxiliary enterprises in power grid companies, the relationship marketing model of DDA has been gradually disintegrated. Lack of independent innovation capability, at the same time, its foreign brands that have been sold or rebranded have no advantage in terms of price. Therefore, the survival status of most of the diversified companies has changed dramatically. Concerned about having scale advantages and cost control capabilities, the downstream demand comes from the domestic leading enterprises with higher proportion of grid companies.
WDM (Wavelength Division Multiplexing) combines two or more optical carrier signals of different wavelengths (carrying various information) at the transmitting end through a multiplexer (also known as a multiplexer), and The technology of transmitting in the same optical fiber coupled to the optical line; at the receiving end, the optical carrier of various wavelengths is separated by a demultiplexer (also called a demultiplexer or demultiplexer), and then the optical carrier is The receiver performs further processing to restore the original signal. This technology of simultaneously transmitting two or more optical signals of different wavelengths in the same optical fiber is called wavelength division multiplexing.
Wavelength division multiplexing is a technology that uses multiple lasers to simultaneously send multiple lasers of different wavelengths on a single fiber. Each signal is transmitted in its unique color band after being modulated by data (text, voice, video, etc.). WDM can greatly increase the capacity of the existing fiber optic infrastructure of telephone companies and other operators. Manufacturers have introduced WDM systems, also called DWDM (Dense Wavelength Division Multiplexing) systems. DWDM can support the simultaneous transmission of more than 150 light waves of different wavelengths, and each light wave can reach a data transmission rate of up to 10Gb/s. This system can provide a data transmission rate of more than 1Tb/s on an optical cable that is thinner than a hair.
Optical communication is a way in which light carries signals for transmission. In the field of optical communications, people are accustomed to naming them by wavelength instead of frequency. Therefore, the so-called Wavelength Division Multiplexing (WDM) is essentially frequency division multiplexing. WDM is a system that carries multiple wavelengths (channels) on one optical fiber, and converts one optical fiber into multiple "virtual" fibers. Of course, each virtual fiber works independently on a different wavelength, which greatly improves the transmission capacity of the optical fiber. . Because of the economy and effectiveness of the WDM system technology, it has become the main means of expanding the capacity of the current optical fiber communication network. As a system concept, wavelength division multiplexing technology usually has three multiplexing methods, namely, wavelength division multiplexing with wavelengths of 1 310 nm and 1 550 nm, sparse wavelength division multiplexing (CWDM, Coarse Wavelength Division Multiplexing) and dense wave Division Multiplexing (DWDM, Dense Wavelength Division Multiplexing).
CWDM, DWDM, FWDM,AAWG WDM
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