Digital Phase Converter

Digital phase converters are often used in locations where three-phase service isn’t available from the utility or is very expensive to install because of a remote location. A process known as double-IGBT conversion is used to generate the third voltage.

A wide variety of industrial and commercial electrical equipment requires 3-phase power. Electric utilities don’t usually install three-phase power as it costs considerably more than single-phase installation. This is why a digital phase converter comes in handy.

A digital phase converter is used to create a three-phase power supply from a single-phase power supply. Most digital phase converters use an inverter and rectifier to create a single voltage. Note that this is done with power electronics that are added to the 2 legs of the incoming single-phase source.

The power-switching devices utilized in the process are called insulated-gate bipolar transistors (IGBT). The new single voltage is able to match both the frequency and voltage of the incoming single-phase power, which results in an output that’s a well-balanced three-phase sine wave, instead of a stepped waveform in a variable frequency drive (VFD).

Digital converters are also more efficient compared to most rotary converters on the market. In contrast to a regular rotary converter, digital converters only use power when a load is present and have minimal internal electric use. Another great benefit of this kind of phase converter is that they’re very quiet.

The digital three-phase converter can’t vary motor speed and frequency like a VFD. With the incredible ability to adjust to different conditions as well as maintain optimal voltage balance, digital phase converters can efficiently and safely operate virtually any kind of 3-phase equipment or multiple loads, which is great.

The input module, also known as a rectifier, consists of many IGBTs in series with inductors.

The IGBTs operate at a switching frequency of about 10,000 Hz and are controlled by software in the DSP in order to draw enough current from the one-phase line in a sinusoidal fashion while charging capacitors on a voltage DC bus (constant). The controlled input of the rectifier allows optimal power factor correction.

The output module, also known as the inverter, consists of multiple IGBTs that draw on the electric power of the DC bus in order to create an AC voltage.

The solid-state design is efficient and results in a pretty small package that has no moving parts apart from small cooling fans. It is worth mentioning that the converters are quite efficient and operate at an efficiency of 95-98%.

A digital phase converter is one of the easiest “plug and play” solutions. It requires the least programming, is simple to install and can be selected based on the motor size.