Generator content

In the practical application of parallel inverters, because of the control signal line of inverters, parallel interconnection line has become the main way of parallel inverters, and information sharing between inverter modules has been realized. Compared with parallel connection lines, parallel connection lines without parallel connection lines have the advantages of good redundancy, high reliability, convenient capacity and maintenance, and broad application prospect. Although the parallel without interconnection can not meet the requirements of practical application, it has greater value and significance for the development and application of parallel inverter technology.

For grid-connected inverters, it is generally believed that the grid is an infinite ideal power supply, so it is unnecessary to consider the parallel control problem. In recent years, with the rapid development of grid-connected photovoltaic power generation in the world and the vigorous promotion of our country, for single-phase grid-connected civil photovoltaic inverters running on the low-voltage side of the grid, the grid can not be simply idealized. At this point, the grid-connected PV inverter can be considered to operate in parallel mode without interconnecting lines. Therefore, it is very necessary to study the non-interconnected parallel technology of PV grid-connected inverters from this point of view.

Third, the application of solar photovoltaic technology

1. Economic benefits

Because solar energy resources are free, with the development of science and technology, the installation cost of the entire system has been within a reasonable range, the economic efficiency of solar photovoltaic system is very high. According to the simulation results, the daily and monthly measured power generation of photovoltaic power generation is analyzed, and the variation law of power generation from low solar radiation to high solar radiation is obtained. The average daily power generation is 31KW and the monthly power generation is 930kw. Due to environmental factors in Jilin Province, power generation efficiency can vary significantly from month to month throughout the year. Through the relationship between availability and month, the photovoltaic power generation efficiency of Jilin Province is obtained, and the annual power generation is 8300kw. Based on the simulation results, measured and calibrated power PV output per hour, measured and predicted instantaneous power comparison, measured and predicted energy PV output, the energy conversion efficiency is obtained.

2. Environmental benefits

There is no exhaust emission during the operation of the photovoltaic power generation system, which will not affect the ambient air quality. When there is no waste water, it will not affect the water environment and the soil environment. This project has no obvious noise source and will not affect the surrounding environmentally sensitive targets. After the completion of the project, the vegetation was not damaged and no large-scale civil works were used. Will not cause soil erosion, will not affect the landscape environment. After the completion of the project, the way of electricity will not affect the ecological environment.

In 2014, Jilin Province built its first civilian photovoltaic power station with the support of Power companies of China. The power plant is located in a residential area of Jilin City, Jilin province. Specific parameters for the installed capacity of 3.5kw, annual power generation of 4200 degrees. According to the domestic 0.42 yuan/degree calculation, the annual income may exceed 5,000 yuan, depending on the relevant project personnel. The annual output can reach about 12%, and the investment can be recovered after 8 years of normal work. It has significant social significance and can reduce a large amount of coal and carbon dioxide emissions every year.

In 2003, Konoweiye Technology Co., LTD., a leading enterprise in Beijing photovoltaic industry, first developed and built the 50KW Beijing Daxing Temple Tower photovoltaic system. This sets a precedent for the application of BIPV in China. For the first time, China has realized the perfect combination of photovoltaics and buildings. The completion and perfect operation of the project provides a good reference for the design of large-scale photovoltaic power stations in China, and lays the foundation for the combination of photovoltaic systems and buildings.

Fourth, the current problems and strategies of solar photovoltaic power generation

(1) The current problems of solar photovoltaic power generation

1. Relatively excess production capacity, guide the healthy development of the polysilicon industry, avoid excessive competition in the industry, and promote energy conservation and emission reduction. The state divides the polysilicon industry into excess capacity industries, and resolutely curbs the trend of polysilicon overcapacity and repetitive construction through economic and administrative means. China's regions and cities are facing a new wave of energy development. More than 100 cities have proposed to build new energy bases. In 2008, China's polysilicon production capacity was 20,000 tons, and production was about 4,000 tons. The capacity under construction is about 80,000 tons, which is obviously excess capacity. In just two years, a sunrise industry with high input, high yield and high threshold has rapidly transformed into an industry with excess capacity, which once again shows that in China's big industrial era, we have formed a common industry with insufficient supply, combination of large and small projects and excess capacity, and eliminated backward production capacity.