What is the current commutation?
What is meant by current commutation? In this process, a current pulse is made to flow in the reverse direction through the conducting thyristor and when the net thyristor current becomes zero, it is turned off.
How many thyristors are used in current commutated step down chopper?
Working Principle of Voltage Commutated Chopper: This circuit comprises of one main thyristor T1 and one auxiliary thyristor TA. Auxiliary thyristor TA, capacitor C, diode D and inductor L basically forms the commutation circuit. Free-wheeling diode FD is connected across the RLE type load.
What is the advantage of current commutated chopper over voltage commutated chopper?
The capacitor always remains charged with the correct polarity. Commutation is reliable as load current is less than the peak commutation current ICP. The auxiliary thyristor TA is naturally commutated as its current passes through zero value.
What is a current chopper?
A chopper is a device that converts fixed DC input to a variable DC output voltage directly. Essentially, a chopper is an electronic switch that is used to interrupt one signal under the control of another.
What are the advantages of load commutated chopper?
Advantage: 1. This chopper is capable of commutating any amount of current. 2.No commutating inductor is required in this chopper circuit which is normally costly, bulky and noisy.
Which commutation is used in choppers?
Current Commutated Chopper Explanation. Current Commutated Chopper is a type of chopper in which commutation of thyristor used in the circuit take place due to oscillatory current through it.
Why forced commutation is used in DC chopper?
A forced commutation chopper control for regulating speed of a DC series tractive motor limits peak motor current by sensing the voltage across the commutation capacitor during the on-time of the current pulses and gating the commutation SCR on in response to a predetermined magnitude of sensed voltage to thereby …
What are the advantages of current commutated chopper?
Advantages of Current Commutated Chopper: Commutation is reliable so long as the load current is less than the peak commutating current. Capacitor is always charged with correct polarity.
What are the disadvantages of load commutated chopper?
Disadvantages. It exhibits low efficiency when dealing with high power applications as at high frequency, switching losses are higher. The capacitor in the circuit carries the full load current at a frequency of half the chopping frequency. The peak load voltage is double the supply voltage.
What is the function of a chopper?