Energy is the foundation for human survival and the lifeline of modern society. At present, coal, oil, and natural gas, the three traditional fossil fuels, remain the three major energy pillars of the world economy. And these three major energy sources are non renewable, and their use will have an impact on the environment. Therefore, vigorously developing renewable energy has become a top priority for the development of the entire society.
Solar energy resources are abundant, widely distributed, and have broad prospects for development and utilization. The most widely used form of solar energy is solar photovoltaic power generation, which has received great attention from countries around the world. In recent decades, the country’s solar photovoltaic industry has developed rapidly and has gained great competitiveness in power generation technology and battery costs. From the perspective of future development, solar photovoltaic power generation has the conditions for development and utilization in terms of technology, economy, and scale, which can effectively reduce total consumption and achieve the goal of non fossil energy.
The process of solar photovoltaic power generation is simple and clean. The process of converting sunlight into electricity does not produce noise or pollution, and the power generation device is sturdy, reliable, and has a long lifespan. Due to the low output voltage of solar photovoltaic cells, we adopted a bipolar inverter grid connected system. Firstly, a Boost boost circuit with a simple structure and convenient control was adopted. Then, after passing through a three-phase full bridge inverter circuit, the inverter from DC to AC was completed and the system was connected to the grid for operation. The control chip adopts TMS320F2812, which collects the DC side voltage, inverter AC, and grid connected voltage signals through a sampling circuit, and then sends them to the DSP. After comparison and analysis, PWM control waveforms are generated to control the opening and closing of the switching tube, thereby achieving maximum power point tracking and grid connected operation for power generation.
The design of an inverter system must ensure that the system has good steady-state, dynamic characteristics, and high conversion efficiency, while also having strict requirements for system safety. To meet the above requirements, first of all, it is necessary to plan the main circuit and control circuit reasonably in hardware, control costs, and leave margin for device capacitance; Secondly, the software should optimize the design of the control system, which is the decisive part of the system’s functional implementation. The implementation of most performance indicators of the inverter cannot be separated from the control system, and the control strategy of the inverter system is also a hot and difficult research topic at present. Therefore, the research on solar photovoltaic inverter grid connected systems has important theoretical significance and engineering practical value.
Solar power generation is a relatively new energy technology, and now industrialized technologies include solar photovoltaic power generation and solar thermal power generation. The photovoltaic effect of solar photovoltaic cells is a prerequisite for making solar power generation possible. The modularity of modules, installation, maintenance, and flexibility in use are the biggest characteristics of solar photovoltaic cells, and have also become the most widely used technology.
The development and utilization of new energy sources such as solar photovoltaics is an important link in maintaining sustainable economic development. However, factors such as high prices of solar photovoltaic cells, low system conversion efficiency, and lack of scale are constraining the development of solar photovoltaic power generation. In recent years, due to the rising cost of conventional energy and the increasingly serious environmental pollution, as well as the continuous development and progress of technology and the improvement of solar photovoltaic module manufacturing processes, prices have decreased rapidly, providing necessary conditions for the further development of solar photovoltaic power generation. With the introduction of a series of national policies, China’s solar photovoltaic industry has entered a period of rapid growth and gradually formed significant technological advantages.
Since the discovery of the photovoltaic effect and the production of the first solar photovoltaic cell, breakthroughs have gradually emerged in the field of solar photovoltaic power generation. With the goal of the “Million Solar Photovoltaic Roof Plan” in the United States in 1997, many developed countries have drafted renewable energy bills based on their specific situations, further accelerating the growth of the solar photovoltaic industry. Since 2000, the global solar photovoltaic industry has been growing at a rate of over 30% for six consecutive years. In 2002, the global battery production was 560MW, and in 2003 it had already reached 750MW. In 2004, Germany revised the Renewable Energy Law, which led to the explosion of the German solar photovoltaic market. In 2004, the global solar photovoltaic production reached 1256MW, and in 2005, it reached 1818MW. It was precisely because of the comprehensive policies of developed countries such as the United States and Japan that the global solar photovoltaic market was able to develop, And unprecedented development prospects and vast horizons have emerged.
Many developed countries in the United States and the European Union have identified solar photovoltaic power generation as an important area of renewable energy and have formulated long-term development plans. By 2020, the total installed capacity of solar photovoltaic power in the European Union will reach 90 million kilowatts, with Germany’s total installed capacity reaching 51 million kilowatts and Spain reaching 10 million kilowatts. The European Union also plans to build large solar photovoltaic power plants in the Sahara Desert to deliver electricity to various parts of Europe, known as the “European Desert Action”. Meanwhile, Germany, Spain, the United States, and others have all enacted specialized laws to support the development of renewable energy.
As the most dynamic country in the world economy, China’s solar photovoltaic industry is developing rapidly. A large number of large-scale solar photovoltaic enterprises have emerged, accounting for a large proportion of the world’s solar photovoltaic production. In 1958, China developed its first silicon single crystal, laying a solid foundation for the research of solar photovoltaic cells. In 1998, the Chinese government began to attach importance to solar photovoltaic power generation and invested in the construction of a 3MW polycrystalline silicon battery and application system demonstration project, which laid the foundation for the rapid development of solar photovoltaic cells in the future. In 2001, Wuxi Shangde established a 10MW solar photovoltaic cell production line, which shortened the gap between China and the international solar photovoltaic industry by 15 years. In 2004, Luoyang Monocrystalline Silicon Factory and China Nonferrous Design Institute jointly established China Silicon High tech Company, which independently developed 12 pairs of energy-saving polycrystalline silicon reduction furnaces. On this basis, in 2005, the first 300 ton polysilicon production project in China was completed and put into operation, thus opening the prelude to the great development of polysilicon in China. In 2007, China became the country with the highest production of solar photovoltaic cells, and in 2011, China’s solar photovoltaic cell production reached 21.3GW.
From the perspective of resource orientation, China’s resources are very abundant, and the territory suitable for solar photovoltaic power generation is very large. For example, regions such as the Qinghai Tibet Plateau and the Loess Plateau account for two-thirds of our territory, with great potential for development and utilization. Although solar photovoltaic power generation has significant advantages in terms of resources, compared to conventional electricity, the following issues must be mainly addressed:
- Economic conditions are the main factor for development.
- Grid connected operation technology is a key factor in development.
- Relevant policy documents and regulations to promote solar power generation.
- The solar photovoltaic manufacturing industry needs transformation and upgrading.
So, the current development of China’s solar photovoltaic industry presents both opportunities and challenges. How to better address these two issues will determine the direction of China’s solar photovoltaic industry development in the future.