Semi converter single phase

WordPress Shortcode. Share Email. Top clipped slide. Download Now Download Download to read offline. Raviraj solanki Follow. Student at sroff. Selection Of Circuit Breaker. Engineering Economics and Management. FACT devices. Related Books Free with a 30 day trial from Scribd. Related Audiobooks Free with a 30 day trial from Scribd. Elizabeth Howell. Debasis Chatterjee Nov. Thyristor 3. Energy is stored in inductor during time t 01to t1. This diode is described as a commutating diode, flywheel diode or by-pass diode.

This diode is commonly described as a commutating diode as its function is to commutate or transfer load current away from the rectifier whenever the load-voltage goes into a reverse-state. This diode serves two main functions: I It prevents reversal of load voltage except for small diode voltage-drop. The additional pair of devices that leads to extra voltage drop across the diodes is the disadvantage of the bridge rectifier.

For this reason, sometimes a single quadrant semi-controlled bridge is used with two Diodes and two Thyristors. Then current through the load and voltage drop across the load are zero, and all the supply voltage appears between the anode and cathode of the SCR.

Then the supply terminals are connected to the load through the SCR and the current starts flowing through the load via SCR. Again during the third positive half cycle supply is positive again SCR is forward biased and if we give triggering pulse, then SCR starts conducting and this cycle repeats.

Generation of firing pulse 1. The below is the operation of a single-phase semi-converter with resistive load. The circuit diagram of a single-phase semi converter or single-phase half-controlled bridge converter with resistive load is shown below. In the above figure, thyristor T 1 and diode D 1 are forward biased and thyristor T 2 and diode D 2 are reverse biased during the positive half cycles of the supply voltage.

But, until T 1 is triggered, the circuit acts as an open circuit and no flow of load current. So, the entire supply voltage appears across T 1 till it is triggered. The operation of the circuit during the positive half cycle of the supply voltage is shown below.

Therefore, except for a small voltage drop across T 1 and D 1 , the entire supply voltage appears across the load resistance R. The thyristor T 1 and diode D 1 will remain forward biased and carry the load current until the positive half cycle ends. When the negative half cycle of the supply voltage starts, thyristor T 2 and diode D 2 come into the forward biased condition, and thyristor T 1 and diode D 1 will be reverse biased.

Thus T 1 and D 1 will stop conducting in the negative half cycle.