Grid connected power generation system

光伏并网系统由组件支架并网逆变器并网柜组成，太阳能电池板发出的直流电，经逆变器转换成交流电送入电网。目前主要有有大型地面电站中型工商业电站和小型家用电站三种形式。

The photovoltaic grid connected system consists of component brackets, grid connected inverters, and grid connected cabinets. The direct current generated by the solar panels is converted into alternating current by the inverters and sent to the power grid. At present, there are mainly three forms: large ground power stations, medium-sized industrial and commercial power stations, and small household power stations.

由于并网光伏发电系统不需要使用蓄电池，节省了成本。发布的并网新政策已经明确表示，家庭光伏电站可以免费入网，多余的电还可以卖给电力公司。从投资的长远角度，按家庭光伏电站25年的使用寿命计算，6-10年左右可以回收成本，剩下的十几年就是赚到的。

Due to the fact that grid connected photovoltaic power generation systems do not require the use of batteries, costs are saved. The new grid connection policy released by the country has clearly stated that home photovoltaic power stations can be connected to the grid for free, and excess electricity can be sold to power companies. From the long-term perspective of investment, based on the 25 year service life of a household photovoltaic power plant, costs can be recovered in around 6-10 years, and the remaining ten years are earned.

但是，并网也有其缺点，就是当公共电网断电时，光伏发电也不能运行。但是如果把其中的并网逆变器换成储能逆变器，电站就可以正常运转。

However, grid connection also has its drawbacks, that is, when the public grid loses power, photovoltaic power generation cannot operate. But if the grid connected inverter is replaced with an energy storage inverter, the power plant can operate normally.

离网发电系统

Off grid power generation system

离网型光伏发电系统，不依赖电网而独立运行，广泛应用于偏僻山区无电区海岛通讯基站和路灯等应用场所。系统一般由太阳电池组件组成的光伏方阵太阳能控制器，逆变器蓄电池组负载等构成。光伏方阵在有光照的情况下将太阳能转换为电能，通过太阳能控制逆变一体机给负载供电，同时给蓄电池组充电；在无光照时，由蓄电池通过逆变器给交流负载供电。

Off grid photovoltaic power generation systems operate independently of the power grid and are widely used in remote mountainous areas, such as island communication base stations and street lights. The system generally consists of a photovoltaic array solar controller composed of solar cell components, an inverter battery pack load, etc. The photovoltaic array converts solar energy into electrical energy under illumination, and supplies power to the load through the solar controlled inverter integrated machine, while charging the battery pack; When there is no light, the battery supplies power to the AC load through the inverter.

这种系统由于必须配备蓄电池，且占据了发电系统30－50%的成本。而且铅酸蓄电池的使用寿命一般都在3－5年，过后又得更换，这更是增加了使用成本。而经济性来说，很难得到大范围的推广使用，因此不适合用电方便的地方使用。

This system requires batteries and accounts for 30-50% of the cost of the power generation system. Moreover, the service life of lead-acid batteries is generally 3-5 years, and they have to be replaced later, which further increases the cost of use. Economically speaking, it is difficult to promote and use it on a large scale, so it is not suitable for use in places where electricity is convenient.

对于无电网地区或经常停电地区家庭来说，离网系统具有很强的实用性。特别是单纯为了解决停电时的照明问题，可以采用直流节能灯，非常实用。因此，离网发电系统是专门针对无电网地区或经常停电地区场所使用的。

For households in areas without power grids or areas with frequent power outages, off grid systems have strong practicality. Especially to solve the lighting problem during power outages, DC energy-saving lamps can be used, which is very practical. Therefore, off grid power generation systems are specifically designed for use in areas without power grids or areas with frequent power outages.