The VSI operates by switching the DC input voltage on and off rapidly, producing a square wave output. This output is then filtered to create a more sinusoidal waveform, suitable for most AC applications. . The voltage source inverter is a somewhat older design and less expensive to implement. Various implementations of the VSI are also known as six-step, twelve-step, or even eighteen-step inverters. How Does a Voltage Source Inverter Work? In the voltage source inverter (vsi), the switches are turned. . Definition: A voltage source inverter or VSI is a device that converts unidirectional voltage waveform into a bidirectional voltage waveform, in other words, it is a converter that converts its voltage from DC form to AC form. An ideal voltage source inverter keeps the voltage constant through-out. . In the domain of power electronics and electrical engineering, the Voltage Source Inverter (VSI) stands as a pivotal technology for converting direct current (DC) into alternating current (AC) with controllable voltage and frequency.