brief introduction
Usually, the process of converting AC power into DC power is called rectification, the circuit that completes the rectification function is called rectification circuit, and the device that realizes the rectification process is called rectification equipment or rectifier. Accordingly, the process of converting DC energy into AC energy is called inverter, the circuit that completes the inverter function is called inverter circuit, and the device that realizes the inverter process is called inverter equipment or inverter.
Inverter, also known as power regulator, can be divided into independent power supply and grid-connected power supply according to its application in photovoltaic power generation system. According to the waveform modulation mode, it can be divided into square wave inverter, step wave inverter, sine wave inverter and combined three-phase inverter. Inverters used in grid-connected systems can be divided into transformer inverters and transformerless inverters according to the presence or absence of transformers.
Structural principle and composition
Inverter is a power regulating device composed of semiconductor devices, which is mainly used to convert DC power into AC power. Generally, it consists of a booster circuit and an inverter bridge circuit. The boost circuit boosts the DC voltage of the solar cell to the DC voltage required for inverter output control; The inverter bridge circuit equivalently converts the boosted DC voltage into the same frequency AC voltage. Inverter is mainly composed of switching elements such as transistors. By regularly turning on and off the switching elements, the DC input is changed into an AC output. Of course, it is not practical to simply generate the inverter output waveform through the switching circuit. Generally, it is necessary to adopt high frequency pulse width modulation (SPWM) to narrow the voltage width near the two ends of the sine wave and widen the voltage width at the center of the sine wave, and always let the switching elements move in one direction at a certain frequency within half a period, thus forming a pulse train (quasi-sine wave). Then let the pulse wave pass through a simple filter to form a sine wave.
Photovoltaic inverter usually consists of three parts: 1, current sensor; 2. Current transformer; 3. Reactor.
Ranking of photovoltaic inverter manufacturers
Having said that, we can see that the quality of photovoltaic inverter is particularly important. According to the information obtained by Bian Xiao, the domestic and foreign PV inverter manufacturers are ranked as follows:
domestic
1. Sunshine Power Co., Ltd.
2. Shenzhen Costa Technology Co., Ltd..
3. Xiamen Ke Hua Hang Seng Co., Ltd.
4. Guangdong Zhicheng Champion Group Co., Ltd.
5. Beijing Kono Ye Wei Technology Co., Ltd.
6. Nanjing Guanya Power Equipment Co., Ltd..
7. Anhui Yihe New Energy Technology Co., Ltd
8. Li Yingwei New Energy Technology (Shanghai) Co., Ltd.
9. Nanjing Nanrui Solar Energy Technology Co., Ltd.
10. Nanjing Guodian Nanzi New Energy Engineering Technology Co., Ltd.
transmarine
Theme area (abbreviation of subject matter area)
1. Power One
2. Kako
3. Fronius
4. advanced? vitality
5.Enphase？ vitality
6.danfoss? Solar energy? inverter
7.Omron? company
8. Refugees
9. Schneider? electrical
So much for the introduction of photovoltaic inverter. After reading this article, friends should have a deeper understanding of the structure and principle of photovoltaic inverter and its position in photovoltaic power generation system. If you have friends who want to install photovoltaic power generation system, you should pay special attention to the quality of photovoltaic inverter. Behind the article is the comprehensive ranking of domestic and foreign photovoltaic production enterprises compiled by Bian Xiao, which can be used as a reference by friends in need.