Operating principle of three phase half wave uncontrolled rectifier
Operating principle of three phase half wave uncontrolled Rectifier:
- In a three phase half wave uncontrolled converter the anode of a diode is connected to each phase voltage source. The cathodes of all three diodes are connected together to form the positive load terminal. The negative terminal of the load is connected to the supply neutral.
- It should be noted that for the type of load chosen the converter always operates in the continuous conduction mode. The conduction diagram for the diodes can be drawn easily from the conduction diagram.
- Since the diodes can block only negative voltage it follows from the conduction table that a phase diode conducts only when that phase voltage is maximum of the three. Once the conduction diagram is drawn other waveforms are easily obtained from the supply voltage waveforms in conjunction with the conduction table.
- The phase current waveforms deserve special mention. All of them have a dc component which flows through the ac source. This may cause “dc saturation” in the ac side transformer. This is one reason for which the converter configuration is not preferred very much in practice.
- From the waveforms,