太陽能供電系統(tǒng)中的主要部分，也是太陽能供電系統(tǒng)中價值最高的部件，光伏組件是將太陽光能直接轉變?yōu)橹绷麟娔艿年柟獍l(fā)電裝置。根據(jù)用戶對功率和電壓的不同要求，數(shù)個光伏組件經(jīng)過串聯(lián)（以滿足電壓要求）和并聯(lián)（以滿足電流要求），形成供電陣列提供更大的電功率。太陽電池的發(fā)電量隨著日照強度的增加按比例增加。隨著組件表面的溫度升高而略有下降。隨著溫度的變化，電池組件的電流、電壓、功率也將發(fā)生變化，組件串聯(lián)設計時必須考慮電壓負溫度系數(shù)。

光伏組件有單晶硅組件、多晶硅組件、薄膜組件三種，目前單晶組件占據(jù)主流，效率較高，相同面積采用單晶組件總功率較大，但如果是相同功率，三種組件的發(fā)電量相差不多。三種組件各有其優(yōu)缺點，可根據(jù)項目的特點選擇，單晶效率高，但單價也高，可用于安裝面積有限的場合，多晶效率稍低，但價格稍便宜，可用于經(jīng)費有限的場合，薄膜組件形式多樣，有柔情的、透光的，彩色的等多種，可用于BIPV等場合。

主要功能分為兩部分，太陽能控制器和逆變器，其作用是對太陽能電池組件所發(fā)的電能進行調節(jié)和控制，最大限度地對蓄電池進行充電，并對蓄電池起到過充電保護、過放電保護的作用，同時把組件和蓄電池的直流電逆變成交流電，給交流負載使用。

控制器的作用是把光伏組件發(fā)出來的電，經(jīng)過追蹤和變換，存于蓄電池之中，除此之外，還有保護蓄電池，防止蓄電池過充過放等功能?？刂破鞒Ｓ糜陔x網(wǎng)系統(tǒng)、直流耦合的儲能系統(tǒng)中?？刂破鬏敵鍪请娏麟?，也可以單獨給直流負載使用。

離網(wǎng)逆變器形式多樣化，按輸出波形分為修正波逆變器和正弦波逆變器；按電氣隔離方式又分為高頻正弦波逆變器和工頻正弦波逆變器；把控制器和逆變器分開設計，各自單獨接線，叫分體式，把控制器和逆變器合在一起，叫一體機，也叫逆控制一體機。

▲離網(wǎng)逆變器系列

其主要任務是儲能，以便在沒有光伏時間段保證負載用電。蓄電池是離網(wǎng)系統(tǒng)中的一個重要組成部分，它的優(yōu)劣直接關系到整個系統(tǒng)的可靠程度，然而蓄電池卻又是整個系統(tǒng)中平均無故障時間（MTBF）最短的一種器件。如果用戶能夠正常使用和維護，就能夠延長其使用壽命，反之其使用壽命會顯著縮短，目前光伏儲能系統(tǒng)通常的蓄電池都是電化學儲能，它是利用化學元素做儲能介質，充放電過程伴隨儲能介質的化學反應或者變化。主要包括鉛酸電池、液流電池、鈉硫電池、鋰離子電池等，目前應用以鋰電池和鉛蓄電池為主等，

Photovoltaic module

The main part of the solar power supply system is also the most valuable component of the solar power supply system. Photovoltaic modules are solar power generation devices that convert solar energy directly into direct current power. According to users' different requirements on power and voltage, several PV modules are connected in series (to meet voltage requirements) and in parallel (to meet current requirements) to form a power supply array to provide greater power. The amount of electricity produced by solar cells increases proportionally with the increase in sunlight intensity. It decreases slightly as the temperature of the component surface increases. With the change of temperature, the current, voltage and power of the battery module will also change. The negative voltage temperature coefficient must be considered when the module is designed in series.

There are three types of photovoltaic modules: monocrystal silicon module, polycrystalline silicon module and thin film module. At present, single crystal module occupies the mainstream with high efficiency. The total power of single crystal module is larger in the same area, but if it is the same power, the power generation of the three modules is similar. Each of the three components has its advantages and disadvantages, can be selected according to the characteristics of the project, single crystal efficiency is high, but the unit price is high, can be used for the installation area is limited occasions, polycrystal efficiency is a little lower, but the price is a little cheaper, can be used for the occasion of limited funds, thin film components in various forms, soft, transparent, color, etc., can be used for BIPV and other occasions.

02

Solar controller and inverter

The main function is divided into two parts, the solar controller and the inverter, its role is to adjust and control the solar cell module generated by the electric energy, the maximum charge of the battery, and the battery to play the role of over charge protection, over discharge protection, at the same time, the DC inverter module and battery into alternating current, to the AC load.

The role of the controller is to put the electricity emitted by the photovoltaic module, after tracking and transforming, stored in the battery. In addition, there are functions of protecting the battery, preventing the battery from overcharging and overdischarging. Controllers are often used in off-grid systems and DC coupled energy storage systems. The output of the controller is current, or can be used solely for DC loads.

Off-grid inverter forms are diversified, according to the output waveform can be divided into modified wave inverter and sine wave inverter; According to the electrical isolation mode is divided into high frequency sine wave inverter and power frequency sine wave inverter; The controller and inverter are designed separately and connected separately, which is called split type. The controller and inverter are combined together, which is called all-in-one machine, also called inverse control all-in-one machine.

The picture

▲ Off-grid inverter series

03

Storage battery bank

Its main task is to store energy in order to ensure the load of electricity in the absence of photovoltaic time. The battery is an important part of the off-grid system, its merits and disadvantages are directly related to the reliability of the whole system, but the battery is the whole system in the mean time to failure (MTBF) of a device shortest. If the user can use and maintain normally, its service life can be extended, on the contrary, its service life will be significantly shortened. At present, the usual battery of photovoltaic energy storage system is electrochemical energy storage, which uses chemical elements as the energy storage medium, and the charging and discharging process is accompanied by the chemical reaction or change of the energy storage medium. It mainly includes lead-acid battery, flow battery, sodium-sulfur battery, lithium-ion battery, etc. At present, lithium battery and lead battery are mainly used.