Assertion (A) : In 3-phase converters, the ripple frequency of the con...
The load current is mostly continuous in 3-phase converters. Hence reason is a false statement.
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Assertion (A) : In 3-phase converters, the ripple frequency of the con...
Assertion (A): In 3-phase converters, the ripple frequency of the converter output voltage is higher than in single phase converter.
Reason (R): The load current is mostly discontinuous in 3-phase converters.
Explanation:
The assertion claims that the ripple frequency of the converter output voltage is higher in 3-phase converters compared to single-phase converters. The reason given is that the load current is mostly discontinuous in 3-phase converters.
Understanding the 3-phase converter:
A 3-phase converter is a power electronic device used to convert electrical power between a 3-phase AC system and a DC system. It typically consists of a rectifier section and an inverter section. The rectifier section converts the AC input into DC, and the inverter section converts the DC into AC.
Ripple frequency of converter output voltage:
The ripple frequency refers to the frequency at which the voltage or current waveform deviates from its ideal constant value. In power electronic converters, ripple is inevitable due to the switching action of the semiconductor devices and the reactive components in the circuit.
Ripple frequency in single-phase converters:
In a single-phase converter, the input and output voltages have a frequency of 50 or 60 Hz, depending on the region. The ripple frequency is determined by the switching frequency of the power semiconductor devices used in the conversion process. Generally, the switching frequency is much higher than the input/output frequency, resulting in a ripple frequency that is a multiple of the input/output frequency.
Ripple frequency in 3-phase converters:
In a 3-phase converter, the input and output voltages have a frequency of 50 or 60 Hz, similar to single-phase converters. However, the load current in 3-phase converters is typically more continuous compared to single-phase converters. This is because the load current in a 3-phase system is distributed among three phases, resulting in a smoother and less fluctuating current waveform.
Relation between load current and ripple frequency:
The load current affects the ripple frequency in power electronic converters. In 3-phase converters, the load current is relatively continuous, meaning that the current waveform has fewer variations. As a result, the ripple frequency of the converter output voltage is lower compared to single-phase converters.
Explanation of the correct answer:
The correct answer is option (c) - "A is true but R is false." The assertion is true, as the ripple frequency of the converter output voltage is indeed higher in single-phase converters compared to 3-phase converters. However, the reason given in the statement is incorrect, as the load current is mostly continuous in 3-phase converters, not discontinuous.
Therefore, the ripple frequency in 3-phase converters is lower due to the more continuous load current, contradicting the reason given in the statement.
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