What is multi pulse rectifier?
Multi-pulse rectifiers use phase-shifting transformers to reduce the harmonic content at the input and to allow multiple rectifier stages to operate in series. This is illustrated below for a 12-pulse diode rectifier. Note that it is also possible to utilize thyristor recitifiers in this configuration.
How many diodes will be required for a 24 pulse converter?
Each three-phase system feeds a 6-pulse diode rectifier and the four diode rectifiers are series cascaded to provide a 24-pulse dc output voltage.
What is multi pulse?
Multipulse converters are made up from several converter modules, switching at the fundamental frequency, but properly phase shifted to produce a nearly sinusoidal output voltage. It regulates the voltage magnitude of a controlled ac bus by drawing variable reactive current from the power system.
Which of the following is one of the merit of Multipulse rectifier?
The main feature of the multi pulse rectifier lies in its ability to reduce the line current harmonic distortion. As the pulse number increases, the harmonics present in the input decreases and the Total Harmonic Distortion (THD) reduces.
How does a 12 pulse rectifier work?
A 12-pulse rectifier uses two 6-pulse rectifiers in parallel (12 diodes) to feed a common DC bus. A transformer with one primary and two secondary windings creates a 30 degree phase shift between the two current waveforms, which eliminates the 5th and 7th harmonics and reduces current THD to between 10 and 15 percent.
What is a 12-pulse transformer rectifier?
What is the advantage of twelve or multi bridge pulse converter?
The advantages of Twelve pulse converter are obvious. The ripple content of the ac voltage superimposing the mean value of the dc voltage is reduced greatly. The value of g increases (0.988) effectively improving the power factor.
What are the advantages of 12 pulse converter?
What is the effect of source inductance?
Source inductance has a significant impact on the converter performance because its presence alters the output voltage of the converter. As a result, the output voltage reduces as the load current reduces. In addition, the input current and output voltage waveforms change significantly.
What is the difference between 6-pulse and 12-pulse rectifier?
A 3-phase, full-wave rectifier is a 6-pulse device. The phase angle between successive secondary voltages is 120 deg. In a 12-pulse converter, the phase-shifting transformer converts the 3-phase input to 6-phase voltages, which when rectified, produce 12 ripples in the dc output voltage.
Why is it called 6-pulse rectifier?
This design is commonly referred to as a 6-pulse rectifier because it draws current from the AC source in six pulses. This non-linear current draw can distort the supplied AC power, causing problems for motors and other electronic equipment. The amount of distortion depends on the capacity of the supply circuit.