Solar power inverter is the main component and important part of solar photovoltaic power generation system. In order to ensure the normal operation of solar photovoltaic power generation system, the correct configuration and selection of Solar power inverter becomes important.The inverter configuration shall be determined according to the technical indicators of the whole photovoltaic power generation system and the product sample manual provided by the manufacturer.Generally also focus on the following several technical indicators.   

1. Rated output power

The rated output power represents the power supply capacity of the Solar power inverter to the load.Solar power inverter with high rated output power can carry more power load.When choosing Solar power inverter, we should first consider that it has enough rated power to meet the requirements of the equipment under the maximum load, as well as the expansion of the system and the access of some temporary loads.When the electrical equipment lives on pure resistive load or the power factor is greater than 0.9, the rated output power of Solar power inverter is generally selected to be 10% '15% higher than the total power of the electrical equipment.   

2, output voltage adjustment performance

The adjustment performance of output voltage represents the voltage stabilizing ability of output voltage of Solar power inverter.General Solar power inverter products are given when the dc input voltage is allowed to fluctuate in the range of variation, the Solar power inverter output voltage fluctuation of the percentage of deviation, usually called voltage adjustment rate.A high-performance Solar power inverter should also provide the deviation percentage of the output voltage of the photovoltaic inverter when the load changes from zero to 100 percent, which is usually called load adjustment rate.The voltage adjustment rate of Solar power inverter with good performance should be less than or equal to ±3%, and the load adjustment rate should be less than or equal to ±6%.   

3. Machine efficiency

The efficiency represents the power loss of Solar power inverter.The efficiency of the Solar power inverter with large capacity is also given at full load and at low load.Generally, the efficiency of inverters below KW level should be 80%~85%.The efficiency of 10KW class should be 85%~90%;The efficiency of higher power must be above 90%~95%.The efficiency of the inverter has an important impact on the photovoltaic power generation system to improve the effective power generation and reduce the cost of power generation. Therefore, the selection of Solar power inverter should be compared as far as possible and the products with higher overall efficiency should be selected.   

4. Startup performance

The Solar power inverter should be started reliably under rated load.The high performance Solar power inverter can start at full load for many times without damaging the power switch and other circuits.Small inverter for their own safety, sometimes use soft start or current limit start measures or circuits.   
Photovoltaic industry has become a hot industry in Europe, Australia and now China. Within a few years, domestic Solar power inverter manufacturers have sprung up like bamboo shoots. However, there are certain standards on how to choose Solar power inverter.   
The first consideration is the scale of photovoltaic power station, whether it is a family or an enterprise. However, the establishment of solar photovoltaic power station in China is still relatively few, mainly due to the limitations of housing structure and other conditions, so solar panels cannot be installed. Factories and enterprises still have advantages.Small home photovoltaic power station is mainly for foreign villa installation.   

The second concern is efficiency.The direct point of efficiency is the power generation directly linked, so now more and more Solar power inverter manufacturers on the efficiency of the inverter as the main final consideration is reliable.on grid photovoltaic power generation system is a system that converts the direct current generated by solar cells into alternating current of the same frequency and phase with the voltage of the power grid, and realizes the power supply to the load and the power generation to the power grid.The on grid photovoltaic power generation system consists of photovoltaic array, on grid inverter, controller and relay protection device.Photovoltaic array is the main component of on grid photovoltaic power generation system, which converts the received solar light energy directly into electric energy.Currently, the photovoltaic array used in engineering is generally composed of a certain number of crystalline silicon solar cell elements in series and parallel according to the voltage requirements of the system.   

on grid inverter is the core of the whole on grid photovoltaic power generation system, which inverts the electric energy generated by the photovoltaic array into a sinusoidal current of 220V / 50Hz and integrates it into the grid.Voltage-type inverters are mainly composed of power electronic switching devices and provide power to the grid in the form of pulse width modulation.Generally, the controller is composed of single chip or DSP chip as the core device to control the tracking of high-power points of photovoltaic array zui and control the power and waveform of on grid current of inverter.Relay protection device can ensure the safety of photovoltaic on grid power generation system and power grid.   

Photovoltaic on grid power generation system can be divided into two types according to different design requirements. One is the non-scheduling on grid photovoltaic power generation system, which does not contain energy storage.The other is the scheduling on grid photovoltaic power generation system, which contains energy storage.In the non-dispatching on grid photovoltaic power generation system, the on grid inverter directly converts the direct current generated by the photovoltaic array into the alternating current of the same frequency and phase with the grid voltage, and the on grid time and power size are completely determined by sunshine, environmental temperature and other factors.Its advantage is that the system can eliminate the battery and use the grid as its energy storage unit.   

When the sunlight is strong, the excess energy generated by the on grid photovoltaic power generation system will be fed back to the grid, and the grid can output the electricity when the electricity is needed.The scheduling on grid photovoltaic power generation system adds an energy storage link. The system first charges the energy storage link, and then USES the on grid photovoltaic power generation system as on grid or independently after inverting as required. The working time and on grid power of the system can be set manually.When power failure or other faults occur in the power grid, the inverter will automatically cut off the electrical connection with the power grid. At the same time, the inverter can choose whether to carry out independent inverter or not as required to continue the power supply to the local load.