Quick Answer: What Is Overlap Angle?

What is the effect of source inductance on full converter?

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 voltage commutation?

 A reverse voltage is applied across conducting SCR due to which current through SCR becomes zero and it is getting off. Hence it is called voltage commutation.  Other name of this is impulse commutation. It is because a high reverse voltage will turn off the SCR.

What causes SCR to fail?

A thyristor or diode reverse blocking failure will have a similar effect. … It may be caused by thyristor deterioration, the application of excessive voltage or rate of change of voltage (dv/dt), over-temperature, or it can result from misfiring. Any of these faults will produce the same result as above.

What is extinction angle in power electronics?

In power electronics extinction angle is one where thyristor gets switched off in spite of being reverse biased. The load is fed for the voltage source through the thyristor. … It remains in the ON state till the load current tries to go to a negative value. This instant is defined as the angle extinction.

What is excitation angle?

The excitation angle or angle of incidence is the angle in which the horizontal seismic components are applied with respect to the principal structural axes during a time history analysis.

How SCR is triggered?

Anode cathode forward voltage SCR triggering: This form of SCR triggering or firing occurs when the voltage between the anode and cathode causes avalanche conduction to take place. … As the junction J2 breaks down, current will flow and triggering the SCR to its conducting state.

Is SCR a transistor?

In many ways the Silicon Controlled Rectifier, SCR or just Thyristor as it is more commonly known, is similar in construction to the transistor. It is a multi-layer semiconductor device, hence the “silicon” part of its name.

What is a firing angle?

Firing Angle: The number of degrees from the beginning of the cycle when SCR is switched on is firing angle. Any SCR would start conducting at a particular point on the ac source voltage. The particular point is defined as the firing angle.

What is dual converter in power electronics?

Dual converter- the name itself indicates that it has two converters in it. It is an electric device mostly found in variable speed drivers. It is a power electronics control system to get either polarity DC from AC rectification by the forward converter and reverse converter.

Why SCR is called controlled rectifier?

The diodes are termed as uncontrolled rectifiers as they conduct (during forward bias condition without any control) whenever the anode voltage of the diode is greater than cathode voltage. … Hence, the thyristor is also called as controlled rectifier or silicon controlled rectifier.

What is a commutation of diodes?

Commutation is the process when conduction switches from one supply phase to another. Commutation overlap occurs when there is inductance in the supply circuit of a diode (or thyristor) rectifier. … Rather, the diode will only turn off once the current falls to zero.

What is conduction angle of SCR?

The conduction angle is the time during which the Thyristor is on. Phase Control Using Thyristors. It is important to note that the circuit current is determined by the load and power source.

What is meant by delay angle?

The delay angle is defined as the angle between the zero crossing of the input voltage and the instant the thyristor is fired. … Hence for same voltage and currnt ratings of SCrs, power handled by mid-point configuration is about q. In mid-point converter, each secondary winding should be able to supply the load power.

What is source inductance?

inductance. The presence of source inductance means that commutation of load current from one thyristor to the next, as they are triggered with a firing angle α, can not be instantaneous.