A single phase semiconverter is feeding a highly inductive load and ha...
When freewheeling diode conducts output current exists but output voltage is zero.
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A single phase semiconverter is feeding a highly inductive load and ha...
Explanation:
A single phase semiconverter is a rectifier circuit that converts AC voltage into DC voltage. The output voltage waveform of a single phase semiconverter depends on the firing angle of the thyristor. The output current waveform is determined by the load impedance and the output voltage waveform.
Similarity of output voltage and current waveform:
When the load is purely resistive, the output voltage and current waveforms are similar. This is because the current waveform is proportional to the voltage waveform. However, when the load is highly inductive, the current waveform lags behind the voltage waveform. This is due to the inductive nature of the load, which causes a delay in the current response to the applied voltage.
Effect of freewheeling diode:
A freewheeling diode is connected across the load in a single phase semiconverter to provide a path for the inductive current when the thyristor is turned off. This prevents a voltage spike across the load and protects the thyristor from damage. However, the freewheeling diode also affects the output voltage and current waveforms.
Dissimilarity of output voltage and current waveform:
The presence of the freewheeling diode causes a discontinuity in the output voltage waveform. This is because the diode conducts when the thyristor is turned off, causing a sudden drop in the output voltage. The output current waveform, on the other hand, continues to flow through the load due to the inductive nature of the load. This causes a dissimilarity between the output voltage and current waveforms.
Conclusion:
Therefore, the waveshapes of output voltage and output current in a single phase semiconverter feeding a highly inductive load with a freewheeling diode across the load are not similar. The output voltage waveform exhibits a discontinuity due to the presence of the freewheeling diode, while the output current waveform continues to flow through the load due to the inductive nature of the load.
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