PV inverters are used in the field of solar photovoltaic inverter dedicated . It will direct current generated by solar cells through the power electronic conversion technology converts directly into the grid , load sharing power. Photovoltaic system is indispensable core components.
The core of the inverter unit switching the inverter circuit , referred to as the inverter circuit . The circuit through the power electronic switch turn-on and turn-off to complete inverter function. For inverter classified in many ways, for example : According to the inverter output AC voltage phase can be divided into single-phase and three-phase inverter inverter ; inverter used according to different types of semiconductor devices , but also divided transistor inverter, thyristor inverters and turn-off thyristor inverters .
According to the principle of the invertercircuit different , can be divided into self-oscillating inverter, step wave superimposed pulse width modulation inverter and inverter and so on. Depending on the application and network systems , or in off-grid systems can be divided into grid-connected inverter and off-grid inverter.
Centralized Inverter: Inverter technology is the focus of a number of parallel PV strings are connected to the same central inverters DC input terminal , the general power of the IGB T three-phase power modules, power smaller using field-effect transistors , while the DSP switch controller to improve the quality of the produced electricity , making it very close to the sine wave current , generally used for large-scale photovoltaic power plants (> 10kW) system.
String inverters : string inverter is based on a modular concept based on each PV string (1-5kW) through an inverter , the DC side has a maximum peak power tracking , parallel to the AC side grid . Many large-scale photovoltaic power plants using string inverters .
Micro Inverter: in the micro- on grid inverter photovoltaic system , solar panels are access each one a micro inverter, when the solar panels can not have a good job , only this one will be affected, while other photovoltaic panels will be run in the best working condition , making the overall system more efficient, generating a greater amount .