Explanation: Space harmonics of the order of 6K-1(5,11,17,…) have their constant amplitude equal to 1/(6K-1)F1 and rotate in the direction of fundamental component F1 at a speed of 1/(6K+1) of the fundamental synchronous speed. 2. Which of the following harmonics are present in the resultant MMF produced by 3 phase currents flowing in the 3 phase windings?
A. Triplen harmonics (3K), where K is an integer
B. 6K+1 harmonics only, where K is an integer
C. 6K-1 harmonics only, where K is an integer
D. 6k+1 and 6K-1 harmonics, where K is an integer
Answer:A
Explanation: Space harmonics of the order of 6K-1(5,11,17,…) have their constant amplitude equal to 1/(6K-1)F1 and rotate in the direction of fundamental component F1 at a speed of 1/(6K+1) of the fundamental synchronous speed. 2. Which of the following harmonics are present in the resultant MMF produced by 3 phase currents flowing in the 3 phase windings?
A. Triplen harmonics (3K), where K is an integer B. 6K+1 harmonics only, where K is an integer C. 6K-1 harmonics only, where K is an integer D. 6k+1 and 6K-1 harmonics, where K is an integer
Explanation: Space harmonics of the order 3,9,15,… i.e, triplen harmonics are absent. 3. When a single-phase winding is excited by an alternating current, then which of the following statements are correct?