Common voltage for industrial frequency inverters

What is common-mode voltage in inverters?

In induction motor drives, the common-mode voltage appears between the start point of the induction motor and the ground. It causes common-mode current to flow through the motor bearings, which is harmful to the machine’s life. Let’s take a look at some of the other effects caused by common-mode mode voltage in inverters in the upcoming section.

Do inverters produce high-frequency voltage waveforms?

However, unlike ‘traditional’ grid-connected machines, such inverters inherently produce high-frequency, large-amplitude common-mode voltage waveforms, unless specific design measures are taken.

Which type of inverter is used in high-power industrial applications?

Inverters are commonly used in high-power industrial applications such as interrupted power supplies, AC motor drives, induction heating, etc. Usually, inverters are pulse-width modulated (PWM) for industrial applications. The most commonly used type of PWM is sinusoidal pulse-width modulation (SPWM) due to its rugged control scheme and simplicity.

What is common mode voltage?

This voltage difference in inverters is referred to as common-mode voltage. Consider a three-phase inverter supplied from a single DC source and connected to a three-phase load. In the three-phase inverter, the common-mode voltage can be measured between the load neutral point and the general ground.