The grid connected photovoltaic power generation system consists of a photovoltaic cell array, a controller, and a grid connected inverter, which directly feeds electrical energy into the public grid through the grid connected inverter. By directly inputting electrical energy into the power grid, there is no need to configure batteries, which saves the process of battery energy storage and release, reduces energy loss, saves space occupied, system investment and maintenance, and reduces costs; On the other hand, the power generation capacity can be large and can ensure the reliability of the power supply for electrical equipment. However, due to the parallel connection between the inverter output and the power grid, it is necessary to maintain the consistency of electrical characteristics such as voltage, phase, and frequency between the two sets of power sources, otherwise it will cause mutual charging and discharging between the two sets of power sources, causing internal friction and instability of the entire power system.

1.并网光伏发电系统几种形式

1. Several forms of grid connected photovoltaic power generation system

并网光伏发电系统是目前发展为迅速的太阳能光伏发电应用方式，随着光伏建筑一体化的飞速发展，各种各样的并网光伏发电系统都得到了广泛的应用。并网光伏发电系统包括如下几种形式：

Grid connected photovoltaic power generation system is currently the fastest developing application of solar photovoltaic power generation. With the rapid development of photovoltaic building integration, various grid connected photovoltaic power generation systems have been widely used. The grid connected photovoltaic power generation system includes the following forms:

①纯并网光伏发电系统。

① Pure grid connected photovoltaic power generation system.

②具有UPS功能的并网光伏发电系统。

② A grid connected photovoltaic power generation system with UPS function.

③并网光伏发电混合系统。

③ Grid connected photovoltaic power generation hybrid system.

2.并网光伏发电系统优点

2. Advantages of grid connected photovoltaic power generation system

太阳能并网光伏发电系统通过把太阳能转化为电能，不经过蓄电池储能，直接通过并网逆变器，把电能并入电网。太阳能并网光伏发电系统代表了太阳能光伏发电系统的发展方向，是21世纪具吸引力的能源利用技术。与离网太阳能光伏发电系统相比，并网光伏发电系统具有以下优点：

The solar grid connected photovoltaic power generation system converts solar energy into electrical energy, without storage batteries, and directly integrates electrical energy into the grid through grid connected inverters. The solar grid connected photovoltaic power generation system represents the development direction of solar photovoltaic power generation systems and is the most attractive energy utilization technology in the 21st century. Compared with off grid solar photovoltaic power generation systems, grid connected photovoltaic power generation systems have the following advantages:

①利用清洁干净、可再生的太阳能发电，不耗用不可再生资源，使用中无温室气体和污染物排放，与生态环境和谐，符合经济社会可持续发展战略。

① Utilizing clean and renewable solar power generation, without consuming non renewable resources, without greenhouse gas and pollutant emissions during use, is in harmony with the ecological environment, and is in line with the sustainable development strategy of the economy and society.

②所发电能馈入电网，以电网为储能装置，省掉蓄电池，比离网太阳能光伏发电系统的建设投资可减少35％～45％，从而使发电成本大为降低。省掉蓄电池并可提高系统的平均无故障时间和蓄电池的二次污染。

② The generated energy is fed into the power grid and used as an energy storage device, eliminating the need for batteries. Compared to the construction investment of off grid solar photovoltaic power generation systems, the investment can be reduced by 35% to 45%, thereby greatly reducing the cost of power generation. Eliminating batteries can improve the average time between failures of the system and the secondary pollution of batteries.

③在设计中使太阳能电池组件与建筑物完美结合，既可发电又能作为建筑材料和装饰材料，使物质资源充分利用发挥多种功能，不但有利于降低建设费用，并且还使建筑物科技含量提高。

③ In the design, the perfect combination of solar cell modules with buildings can generate electricity and serve as building materials and decorative materials, fully utilizing material resources and exerting various functions. This not only helps to reduce construction costs, but also improves the technological content of buildings.

④分布式建设，就近就地分散发供电，并入和退出电网灵活，既有利于增强电力系统抵御自然灾害的能力，又有利于改善电力系统的负载平衡，并可降低输电线路损耗。

④ Distributed construction, with locally distributed power generation and supply, and flexible integration and exit from the power grid, not only enhances the ability of the power system to withstand natural disasters, but also improves the load balance of the power system and reduces transmission line losses.

⑤可起调峰作用。并网光伏发电系统是世界各发达在光伏应用领域竞相发展的热点和重点，是世界太阳能光伏发电的主流发展趋势，市场巨大，前景广阔。

⑤ It can play a peak shaving role. Grid connected photovoltaic power generation system is a hot and key development topic in the photovoltaic application field in developed countries around the world, and it is the mainstream development trend of solar photovoltaic power generation in the world. The market is huge and the prospects are broad.