What is 3 phase rectification?

We have seen in this tutorial that three-phase rectification is the process of converting a 3-phase AC supply into a pulsating DC voltage as rectification converts the input power supply of a sinusoidal voltage and frequency into a fixed voltage DC power. Thus power rectification changes an alternating supply into a unidirectional supply.

Why is a 3-phase supply used in a rectification circuit?

Since a 3-phase supply has a fixed voltage and frequency it can be used by a rectification circuit to produce a fixed voltage DC power which can then be filtered resulting in an output DC voltage with less ripple compared to a single-phase rectifying circuit.

How does a controlled 3-phase rectification work?

Thus with a controlled 3-phase rectification which uses thyristors instead of diodes, we can control the value of the average DC output voltage by controlling the firing angle of the thyristor pairs and so the rectified output voltage becomes a function of the firing angle, α.

What is a rectifier approach?

The rectifier approach has enabled the conversion of a linear power generation of a three-phase VSR AC signal to the DC signal of the system. The overall stability and control of the dc side have been established, as well as the unit power factor control.

How many diodes does a 3 phase bridge rectifier use?

The full-wave three-phase uncontrolled bridge rectifier circuit uses six diodes, two per phase in a similar fashion to the single-phase bridge rectifier. A 3-phase full-wave rectifier is obtained by using two half-wave rectifier circuits.

Where does conduction occur in a 3-phase power rectifier?

In 3-phase power rectifiers, conduction always occurs in the most positive diode and the corresponding most negative diode. Thus as the three phases rotate across the rectifier terminals, conduction is passed from diode to diode.