Solar inverters are a critical component of any solar energy system, converting the DC power generated by solar panels into AC power that can be used by household appliances or fed back into the grid. With the ever-evolving solar technology, it is no surprise that the world of solar inverters has seen significant advancements in recent years. The options available to consumers have expanded as manufacturers continue to innovate and improve upon existing designs. In particular, two types of inverters have become popular: the two-level inverter and the multi-level inverter. From traditional two-level inverters to the latest multi-level inverters, the solar industry has come a long way in terms of efficiency and sustainability. In this article, we will explore the differences between these two types of inverters and discuss the benefits and drawbacks of each.

Two-Level Inverter

The two-level inverter is a simple type of inverter that converts DC power to AC power by using Pulse Width Modulation (PWM) to generate a square wave output voltage. This voltage can then be fed to a transformer to increase the voltage and convert it to AC power. While this type of inverter is simple to design and control, it has some limitations. For example, the output voltage waveform of a two-level inverter is distorted, which results in poor Total Harmonic Distortion (THD) of the voltage. Additionally, the efficiency of a two-level inverter is limited by the voltage rating of its switches, which must be high enough to withstand the full DC voltage of the solar array.

Multi-Level Inverter

To address the limitations of two-level inverters, multi-level inverters have been developed. Multi-level inverters use a combination of switched blocking and conduction components to produce a smooth output waveform with lower THD than a two-level inverter. The following are the major differences between the two kinds.

Voltage Reduction

By increasing the DC voltage of the solar array to 1000V or 1500V, the current can be reduced, which results in smaller power conducting devices and less copper required in the design. However, this high voltage can be difficult to manage and finding components that can withstand such voltage can be challenging. Multi-level inverters help to address this issue by spreading the voltage over several levels.