A solar inverter is a type of electrical converter which converts the variable direct current (DC) output of a photovoltaic (PV) solar panel into a utility frequency alternating current (AC) that can be fed into a commercial electrical grid or used by a local, off-grid electrical network.
A large number of PV inverters is available on the market – but the devices are classified on the basis of three important characteristics: power, DC-related design, and circuit topology. 1. Power The available power output starts at two kilowatts and extends into the megawatt range.
What is a photovoltaic inverter?
As introduced in Chap. 1, the photovoltaic (PV) inverters are the key link responsible for converting solar energy into electricity. The topology and control technology directly determine the investment costs, conversion efficiency, and output performance of the PV generation system. There are many topologies for connecting PV modules to the grid.
Typical outputs are 5 kW for private home rooftop plants, 10 – 20 kW for commercial plants (e.g., factory or barn roofs) and 500 – 800 kW for use in PV power stations. 2. Module wiring The DC-related design concerns the wiring of the PV modules to the inverter.
In order to couple a solar inverter with a PV plant, it's important to check that a few parameters match among them. Once the photovoltaic string is designed, it's possible to calculate the maximum open-circuit voltage (Voc,MAX) on the DC side (according to the IEC standard).
Do PV inverters meet the requirements for commercialization of PV power generation?
It should be noted that the power, DC voltage, and AC current are the basic control objectives for the commonly used PV inverter, which merely satisfy the basic normal operation requirements. However, to meet the requirements of commercialization of PV power generation, some special performance indexes have to be satisfied.
What are the stages of a PV inverter?
Stage 1, stage 2, and stage 3 form the typically cascaded control structure. It should be noted that the power, DC voltage, and AC current are the basic control objectives for the commonly used PV inverter, which merely satisfy the basic normal operation requirements.