First of all, what is an inverter? Simply put, it is an electronic device that converts low-voltage DC into AC. We usually convert alternating current into direct current for use, and the function of inverter is just the opposite, hence the name.
Simply speaking, frequency converter is a control device that converts unstable electric energy into constant voltage and frequency electric energy according to the principle of rectification and inverter. Include rectifier (AC to DC), inverter (DC to AC), AC converter and DC converter.
Photovoltaic inverter
Because solar photovoltaic generates direct current energy, it needs to be converted into alternating current energy with the same frequency and phase as the power grid by an inverter and merged into the power grid (the power grid is generally an alternating current grid, and direct current cannot be directly connected to the power grid). In addition, the inverter also has the functions of active operation and shutdown, maximum power tracking MPPT, islanding detection and control, power grid detection and grid connection. More specifically, the inverter not only changes from DC to AC, but also supervises the current operation, which is somewhat similar to the role of "housekeeper".
Wind converter
The electricity generated by wind power itself is alternating current, but because of the great instability of wind power, and the wind speed and the equipment itself will directly affect the rotation of the generator, it is necessary to sort out the wind power converter, and then turn alternating current into direct current, so as to improve the power quality. In wind power generation equipment, converter is a very important equipment in wind power generation. If the electric energy generated by wind power generation is to be connected to the power grid, the converter is an indispensable device, so it is also the core component to determine whether it can produce economic benefits.
Development mode and trend of photovoltaic inverter
In recent years, all countries in the world are vigorously developing new photovoltaic energy. The rapid growth of photovoltaic power generation installed capacity has also driven the continuous growth of photovoltaic inverter production and sales, and the industry has maintained rapid development. With the domestic photovoltaic inverter market showing great potential, the competition in the inverter market is more intense, and the price is getting closer to the profit critical point. The low price puts great demands on the technical research and development level and product production strength of photovoltaic inverter manufacturers. Small and medium-sized inverter manufacturers, which mainly purchase components and assemble them, will face the test of survival and it is difficult to achieve sustainable development.
Looking at the development and changes of the competition pattern of photovoltaic inverter market, the industry concentration has gradually increased since 10, and the market share of the top ten enterprises in the world has reached 73%. In terms of breakdown structure, 1-3 is stable, with a market share of about 45%, and 4- 10 is constantly rotating, with a market share of about 30%, with a stable head and fierce competition at the waist.
According to the application scenarios and power, photovoltaic inverters can be divided into three types: centralized inverter (28.5%), series inverter (66.5%) and micro inverter. Among them, series inverter is one of the three major trends in the future industry.
Centralized inverter: large-scale ground, water surface and industrial and commercial roof (500-3400kw)
Advantages: mature technology, few inverters and components, few fault points and high reliability.
Disadvantages: the total power is greatly influenced by a single solar cell, which requires a large space to arrange inverters, complicated later maintenance and high total cost.
Representative enterprises: Huawei, Sunshine Power, Shangneng Electric and other enterprises.
Series inverters: small distributed and ground stations-industrial and commercial roofs, complex mountainous areas (20-300kw) and household (below 20kw) have the best control effect;
Advantages: The inverter is small in size, light in weight, convenient to install, and can maximize the power generation.
Disadvantages: There are many inverters and electronic components, and the total failure rate is relatively high.
Representative enterprises: Jinlang Technology, Goodway, etc.
Micro inverter: Single machine capacity is generally below 1kw, and multi-channel MPPT+ single machine centralized inverter.
Advantages: simple and safe installation, and maximum power generation.
Disadvantages: high price and small scope of application.
Judging from the current market situation of photovoltaic inverter, the market share of micro inverter is small, and centralized inverter is the first choice in the early stage of photovoltaic development. Due to inconvenient installation, the total cost is high and the growth rate is not as good as before. Series inverters are favored by users because of their low price and convenient installation, and their market share is constantly improving. In just a few years, Huawei, which has become the world's largest supplier of photovoltaic inverters, focuses on a series of inverter products.
Series inverter is suitable for distributed photovoltaic application scenarios, and it is also extended to centralized ground power station scenarios. With the increase of downstream application scenarios, the proportion of distributed photovoltaic continues to increase. It is estimated that the market space of series inverters will reach 52.3 billion in 2020-2025, with a compound growth rate of 14%, which is huge!
202 1 top ten photovoltaic inverter brands list:
1, Huawei 2, Sunshine Power Supply
3. Shangneng Electric 4. Guruiwat
Highway 5.6. TBEA
7. Ke Hua data 8. Co-performer
9. Jinlang Technology 10, maiden voyage of new energy.
Competition pattern and development trend of wind power converter industry
Domestic wind power converter manufacturers started late. For a long time, wind power converters have been monopolized by several foreign electrical giants, such as ABB, Siemens, Emerson and so on, because of the difficulty in technical and technological design and high reliability requirements. However, with the rapid development of domestic wind power industry and the support of national policies, domestic inverter manufacturers have made great efforts. After continuous efforts and competition in the industry during the Twelfth Five-Year Plan period, domestic onshore wind power converters have become the dominant market in China, and the market share of imported products has been declining year by year, and some enterprises have even faded out of the competition in the domestic wind power market.
It is worth noting that compared with onshore wind power converters, offshore wind power converters have more stringent requirements on product power, reliability, stability and high humidity and high salt spray performance, and the technical barriers are extremely high. The converter products of large international electric companies are mainly used in offshore wind power in China.
At present, there are two main types of participants in the domestic wind power converter market: one is a wind power machine enterprise that can produce wind power converters or its subsidiary that mainly manufactures converters, and its products are mainly supplied to itself or its parent company, represented by Tiancheng Tongchuang, a subsidiary of Goldwind Technology; Second, independent converter manufacturers, represented by Wang He Electric, widely participate in market competition.
It is understood that industry leaders such as Goldwind Technology and Yangming Intelligent have their own converter subsidiaries, and the above-mentioned enterprises also use converter products produced by some third-party manufacturers. For other wind turbine manufacturers, converter products mainly come from third-party suppliers, such as Hopewell Electric, Sunshine Power and Nikko Electric.
Summary:
Inverter and converter are the core components of photovoltaic and wind power generation, and their technical content is relatively high. We have basically realized the localization of photovoltaic inverter; In terms of wind power converters, domestic onshore wind power converters have occupied a dominant position in the domestic market, but the technology of offshore wind power is still relatively weak. In the key technology of converter, there is still a certain gap between China and developed countries such as Europe and America. With the rapid development of wind power in China, especially the construction of offshore wind power, it is necessary to master the core technology. In the future, enterprises with high R&D investment and strong independent innovation ability will come out and master core technologies.