Single-phase Semi-converter with inductive load

Single-phase Semi-converter with inductive load

The what is ac to dc converter with suitable examples and sketches are discuss here advanced. what is ac to dc converter is needed to read.

Semi-controlled Converters

Semi-controlled converter is a hybrid between uncontrolled and fullycontrolled converters.  It is also known as β€œsemi-converter”.

Semi-converter offers variable positive DC output voltage only. Regeneration or inverter mode operation is not available

Single-phase Semi-converter with inductive load

In a semi-converter, thyristor conduction is delayed by angle Ξ± but diode conduction begins at their default points (i.e. zero delay-angle).  For continuous load current (which we assumed), at any time, a thyristor from the upper-half and a diode from the lower-half must conduct the load current πΌπ‘œ, i.e. last two active devices conduct at any point of time.

what is ac to dc converter

By varying 𝛼 over 0Β° to 180Β°, we can adjust  𝑉 π‘œ π‘šπ‘’π‘Žπ‘› between  8𝑉𝑝𝑕 πœ‹  and 0.  

In  𝐼𝑠waveform, front-end of current pulse (in each half-cycle) is moved to the right by 𝛼 but rear-end is fixed.  For a given delay angle 𝛼, the width of current pulse is  πœ‹ βˆ’π›Ό .

Note: We assumed continuous load current for all delay angles.  In reality, at higher delay-angles, load current becomes discontinuous.  Then the input current will be different.

There are some other implementations of the single-phase semi-converter, all offering the same input-output performances.

Standard Implementation what is ac to dc converter

Standard Implementation

Alternative Implementation – 1 what is ac to dc converter

Alternative Implementation – 1

Alternative Implementation – 2 what is ac to dc converter

Alternative Implementation – 2

Alternative Implementation – 3 what is ac to dc converter

Alternative Implementation – 3

Which implementation we want to select is partly our own preference and partly technical /operational requirements.

Thyristors (also diodes) are available as individual devices or multiple devices.  Twin devices are available in common-cathode, common-anode or bridgedleg options.  Selection of the converter configuration may depend on the type of available devices. 

Technically, common-cathode configuration of standard implementation eases the assembly of two gate drive circuits sharing the cathodes.   Threeleg implementation  gives the choice between  semi-converter and fullconverter during operation by making diode D5 in or out.

Self Attempt what is ac to dc converter

Draw the output voltage and input current waveforms for the other three configurations of 1-phase semi-converter, and indicate the devices conducting in different intervals of the cycle.

The what is ac to dc converter with suitable examples and sketches are discuss here advanced. It is needed to read.

Reference what is ac to dc converter

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