Electric switching of photovoltaic inverters

1. Introduction PV inverters use semiconductor devices to transform the DC power into controlled AC power by using Pulse Width Modulation (PWM) switching. PWM switching is the most efficient way to generate AC power, allowing for flexible control of the output magnitude and frequency.

Moreover, the inverters are interconnected in parallel with PV cells, facilitating power conversion in a singular-stage configuration. In the traditional structure of solar power plants, inverters and low-frequency transformers are utilized as an interface between PV panels and the AC grid for power transmission.

In the proposed model, by examining weather conditions and the amount of solar radiation during different hours of the day, a droop control has been presented for inverters to store reactive power in the specified grid.

By directly controlling the switching sequence in inverters, this method is responsible for controlling the output waveforms of current and voltage. Inverter performance is determined by managing and controlling switching losses and fluctuations, facilitating efficient operation according to the switching device's requirements.

A novel transformerless five-level inverter, structured upon the FC topology, has been introduced for utilization in PV grid-connected systems .

To manage the multiple voltage levels and reduce switching losses, multilevel inverters often rely on advanced control techniques such as MPC and SVPWM. These control methods, while effective in optimizing inverter performance, add computational demands and can introduce latency, potentially impacting system reliability.