The phase full-controlled bridge and the double reverse star rectifier circuit are two commonly used rectification methods of the silicon controlled rectifier. Today we analyze what is the three-phase bridge and double reverse star rectified circuit of the silicon controlled rectifier.
Three-phase bridge type fully controlled rectifier circuit
1. Circuit form
2. Working principle
For the output voltage of the load end, there must be a thyristor in the common cathode and common anode groups, and the output voltage waveform of the common cathode group is the positive half-period envelope of the three-phase phase power supply waveform. For the common anode group, the output voltage waveform is the negative half cycle envelope of the three-phase phase power supply waveform.
On the three-phase line voltage waveform is the positive half of the envelope.
(2) When α> 0o
The following picture is α＝30o、α＝60o、α＝90oWaveform
α≤60oTime，ud Waveforms are positive；60o<α<90oTime，due to Ld effect， ud The waveform appears negative，α＝90oTime，Positive and negative areas are equal, ud =0.
3. Quantitative relationship:
（1）Phase shift range 0o~90o
（2）α≤60oTime，Continuous load voltage。
（3）The load voltage is the line voltage.
（4）Requirements for trigger pulse:
The three-phase bridge fully controlled rectifier circuit must ensure that both thyristors are turned on at any time to form a loop. In order to ensure that the rectifier can start working or can be turned on again after the current is interrupted, it must be turned on A pair of thyristors add trigger pulse at the same time. One is wide pulse and the other is double narrow pulse.
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