Three-phase power is typically associated with which of the following benefits?

Three-phase power is typically associated with which of the following benefits?

• A. More pulsating
• B. Higher cost
• C. Less pulsating
• D. Increases line current

Answer: (C)

Three-phase power smooths out the electrical delivery because the three phase voltages are offset by 120 degrees. When these voltages drive a balanced load, the instantaneous power from each phase rises and falls at different times, so their sum stays nearly constant. That is why the overall current and voltage fluctuations seen in a three-phase system are much smaller than in a single-phase system. The practical result is less pulsating power, which leads to smoother motor torque and a steadier supply. The other statements don’t reflect this inherent benefit: three-phase isn’t defined by higher cost, and while current per phase and overall system design can vary with application, the standout advantage is the reduction in pulsations.

Three-phase power smooths out the electrical delivery because the three phase voltages are offset by 120 degrees. When these voltages drive a balanced load, the instantaneous power from each phase rises and falls at different times, so their sum stays nearly constant. That is why the overall current and voltage fluctuations seen in a three-phase system are much smaller than in a single-phase system. The practical result is less pulsating power, which leads to smoother motor torque and a steadier supply. The other statements don’t reflect this inherent benefit: three-phase isn’t defined by higher cost, and while current per phase and overall system design can vary with application, the standout advantage is the reduction in pulsations.