Areas
The high-power converter of a 100-megawatt smart photovoltaic power station belongs to the high-tech fields supported by the state: mechanical transmission technology, power electronics and control fields.

Technological innovation
Solar photovoltaics are one of the most effective ways to solve the energy crisis and environmental pollution. Photovoltaic power stations above 100 megawatts are the mainstream of power generation at home and abroad. According to IHS forecasts, the global installed capacity in 2016 will be 60GW, with a market scale of more than 650 billion yuan; China has 20GW per year during the 13th Five-Year Plan, with a market size of more than 160 billion yuan; the prospects are very broad. Power stations above 100 megawatts face problems such as failure rate and reliability caused by technical difficulties such as zero voltage ride through, PID effects and system resonance around the world, with annual losses reaching 10 billion yuan. Based on the 500/630KW series of high-power converters developed by 100-megawatt photovoltaic power stations, Chint Power has overcome many key technologies and achieved a series of innovative results, which has brought great significance to the efficiency, life improvement and cost reduction of solar power generation., promoting the development of the industry; the details are as follows:

A new converter power supply system is the first in China to solve the power supply problem of the system during zero-voltage ride-through period. It is used in conjunction with a new generation of positive and negative sequence control SVPWM technology to realize the zero-voltage ride-through function and complete the parallel connection of two converter modules, improving the conversion efficiency of 0.5%, ensuring that photovoltaic power stations complete fault ride-through, avoiding power accidents, and improving the reliability of the power system. U.S. invention patent US006985063 B2; Invention patent 201310482663.7; utility patent 201320637139.8;

Created a converter multi-input reverse connection detection circuit with self-diagnosis function, which can detect whether the DC input electrode of the converter is correct in time and avoid faults. This technology fills the domestic gap; invention patent 201310244808.X; utility model patent 201320353455.2;

Breakthrough two PID effect solutions for photovoltaic power stations, solve the problem of photovoltaic panel output power attenuation, and improve the service life of the power station by 20%. Invention patent 201410140647.4, practical patent 201420170349.5 and 201520669731.5; The unique virtual resistance software compensation and hardware resonance suppression circuit technology solve the resonance problem of the power station system, improve the reliability of the power system, and ensure a 25-year service life; soft copy 2014 SR093605;

Created a structural layout of a power module. This technology is the first in China. It solves the heat dissipation problem of 500/630KW series converters, increases the power density of the system by more than 30%, and reduces the cost by 10%. Practical patent 201320265338.0; The leakage current detection method based on the weighted sliding average prediction method can accurately detect the leakage current of the converter to ensure equipment and personal safety; invention patent 201110104215.4.

Application of results
The project's 500/630KW converter achieves a high conversion efficiency of 99%. Compared with products with only one power unit, the required start-up power is 50% less and the power generation is 10% higher. A total of 14 intellectual property rights have been obtained, of which 11 have been authorized, including 1 American invention, 1 China invention, and 3 other inventions that have completed the second substantive review. The 500kW converter has won the title of National Key New Product, and its product search performance indicators have reached the international advanced level. In 2015, it was awarded the title of Top 10 in the city's high-tech achievements transformation. In the past three years, it has achieved sales of 880 million yuan, an annual growth of over 50%. The products have been applied to mainstream countries such as China, Asia-Pacific, Europe and the United States, cultivating more than 200 professional talents in power electronics, saving electricity by 5 billion kilowatt-hours per year, reducing carbon emissions by 600,000 tons, and creating more than 2000 new jobs.