Analysis of Various Inverter and Key Technical Indexes

   As an independent photovoltaic system, the DC power generation voltage is relatively low, so the power regulator, which is the inverter, is absolutely indispensable. In the grid-connected system, two types of inverters are mainly used for AC power generation:
(1) line rectification - the signal in the grid can be used as a reference for synchronization.
(2) self-rectification - through the inverter internal circuit structure to determine the signal waveform, and then enter the power grid.
We can also classify them according to the application of the product:
(1) Central inverter - used to rectify the output of large photovoltaic systems with rated power in the range of 20 to 400 kW. At this stage of the mainstream products with self-rectifier design, through the bipolar transistor and the effect of the transistor to achieve.
(2) series inverter - only allows the reception of signals through independent serial transmission, so the rated power of 1 ~ 3kw.
(3) Duplex series inverter - Equipped with a variety of independent DC-DC inverter, the inverter feedback to the signal to a central inverter device. This design can be applied to a variety of different component connection structure, which can make each row of solar cells on the line output maximum power.
(4) AC component inverter - supporting the installation of each PV module, and then all the components of the output into AC.
(5) Compatible with solar panels - Under standard operating conditions, the maximum output voltage of the solar panel must match the nominal DC input voltage of the inverter. The maximum open circuit voltage of the solar cell must also be within the rated voltage range that the inverter can withstand.
(6) Electromagnetic interference - must meet the relevant technical requirements of the local government.
(7) lightning and other pulse protection - the same, must comply with local technical requirements.
(8) Other - Other key technical indicators to be examined include electrical technical standards, dimensions, weight, installation and materials, protection against different weather conditions, interfaces and measuring equipment.
The price of the different inverters is very different. Despite the decline in prices in recent years, but for the maximum power of less than 5kw system inverter or will account for 20% of the cost, and for larger systems that part of the expenditure will be close to about 10%.