Abstract
A solar micro inverter is a small-size inverter designed for single solar PV module instead of group of solar PV modules. Each module is equipped with a micro inverter to convert the DC electricity into AC electricity and the micro inverter is placed/installed below the module. The advantages of micro inverters are: reduced effect of shading losses, module degradation and soiling losses, enabled module independence, different rating of micro inverter can be connected in parallel to achieve the desired capacity, additional modules can be included at time which allows the good scalability, string design and sizing are avoided, failure of any micro inverter does not affect the overall power generation, individual MPPT controller for each module increases the power generation, any orientation and tilt angle allows higher design flexibility, lower DC voltage increasing the safety, easy to design, handle and install, requires less maintenance, draws attention of design engineers, contractors, etc.
TopIntroduction To Solar Pv System
Solar energy is the one of the major reliable renewable sources. Solar photovoltaic system is used to convert the light energy (photons) into electrical energy from the sunlight. A simple solar PV system consists of solar PV panel and inverter to convert the sunlight into electricity. Solar panel is a device that used to convert the photons in the sun light into DC electricity and inverter is used to convert the DC electricity into AC electricity (Chetan et al., 2012). The simple solar PV system is shown in figure 1.
As per IEEE standard 929 – 2000, solar PV system applications are classified into small application up to 10 kW, intermediate (medium) application from 10 kW to 500 kW and large application more than 500 kW (Patel et al., 2014). Solar PV systems are classified into two types based on the utility power supply, i.e, is standalone system and other one is grid connected system (Chetan et al., 2012).
Grid connected solar PV system is operating in parallel with the utility power supply (Chetan et al., 2012). This system export the power from solar PV system into utility power grid and importing the power from utility power grid to the system. The typical grid connected solar PV system is shown in figure 2.
Figure 2. Grid connected solar PV system
Solar PV systems are classified into two types based on no of phases, they are single phase system and three phase system. The energy consumption of residential systems are very less and residential systems are mostly requires lesser rating solar PV for their demand. Small application of less than 10 kW solar PV systems are mostly used for residential systems. Commercial and small scale industrial systems have the power demand more than 10 kW to several hundred kW. These systems require medium application of solar PV system to cater the loads.
In most of the cases, the grid connected PV systems are preferably used in small scale commercial and industrial systems as compared to standalone PV systems (Chetan et al., 2012). In grid connected system, solar power is used to power the own plant loads and excess amount of power generation from the solar PV is exported into the utility power grid. Large solar PV systems are more than 500 kW rating primarily used for exporting the power to the utility power grid. The three phase solar PV systems are mostly preferred when compared to three numbers of single phase PV systems.