Slot Harmonics Define
- Slot Harmonics Define Math
- Slot Harmonics Define Sound
- Slot Harmonics Define Economics
- Slot Harmonics Define Science
- Slot Harmonics Define Meaning
Slot Harmonics Define Math
Harmonics Defined. When a musical instrument is playing a note, what we are actually hearing is the fundamental pitch, which is the pitch being played by the instrument, accompanied by a series of. Thus the harmonics which are generated in the EMF due to slotting is called slot harmonics. It can be seen that the main source of harmonics is the non-sinusoidal field form which can be made sinusoidal and the harmonics can be eliminated.
Troubleshooting harmonic problems can be like trying to find a needle in a haystack. Every individual load on every branch circuit is a potential harmonic source. However, you can significantly reduce troubleshooting time by determining the harmonic power flow direction on a circuit. Let's say there's a harmonic issue on a branch circuit with ten loads. You would need to connect a monitoring. In some technical papers and advanced text books, slot harmonics are probably described elegantly and completely with diagrams and equations. Unfortunately, no one has answered this question with a reference to such an explanation, so I will attempt an explanation without any supporting references. As a result of small asymmetries on the machine stator or rotor slots or slight irregularities in the winding patterns of a three phase winding of a rotating machine, harmonic currents can develop. These harmonics induce an electromotive force (emf) on the stator windings at a frequency equal to the ratio of speed/wavelength.
harmonica
The harmonica, also French harp, blues harp, and mouth organ, is a free reed wind instrument used worldwide in nearly every musical genre, notably in blues, American folk music, jazz, country, and rock and roll. There are many types of harmonica, including diatonic, chromatic, tremolo, octave, orchestral, and bass versions. A harmonica is played by using the mouth to direct air into and out of one or more holes along a mouthpiece. Behind the holes are chambers containing at least one reed. A harmonica reed is a flat elongated spring typically made of brass or bronze, which is secured at one end over a slot that serves as an airway. When the free end is made to vibrate by the player's air, it alternately blocks and unblocks the airway to produce sound.Reeds are pre-tuned to individual pitches. Tuning may involve changing a reed's length, the weight near its free end, or the stiffness near its fixed end. Longer, heavier and springier reeds produce deeper, lower sounds; shorter, lighter and stiffer reeds make higher-pitched sounds. If, as on most modern harmonicas, a reed is affixed above or below its slot rather than in the plane of the slot, it responds more easily to air flowing in the direction that initially would push it into the slot, i.e., as a closing reed. This difference in response to air direction makes it possible to include both a blow reed and a draw reed in the same air chamber and to play them separately without relying on flaps of plastic or leather to block the nonplaying reed.
The winding factor for a specific winding expresses the ratio of flux linked by that winding compared to flux that would have been linked by a single-layer full-pitch non-skewed integer-slot winding with the same number of turns and one single slot per pole per phase. The torque of an electric motor is proportional to the fundamental winding factor.
Slot Harmonics Define Sound
The winding factors are often expressed for each space harmonic. If a winding factor is referred to without reference to a harmonic number, the fundamental winding factor is addressed. In the Emetor winding calculator, both the fundamental winding factor as well as the winding factor harmonics are calculated.
Slot Harmonics Define Economics
The winding factor $k_w$ can generally be expressed as the product of three factors, the pitch factor $k_p$ (sometimes also called coil-span or chording factor), the breath coefficient or distribution factor $k_d$, and the skew factor $k_s$: $$k_w=k_pcdot k_dcdot k_s$$
The pitch factor $k_p$ reflects the fact that windings are often not fully pitched, i.e. the individual turns are reduced in order to decrease the length of the end-turns and do not cover a full pole-pitch (also called chorded).
Example:
2-pole 6-slot winding with coil span of 3 slot pitches (i.e. full pitch): $k_p=1.0$
2-pole 6-slot winding with coil span of 2 slot pitches: $k_p=0.866$
2-pole 6-slot winding with coil span of 1 slot pitch: $k_p=0.5$
The distribution factor $k_d$ reflects the fact that the winding coils of each phase are distributed in a number of slots. Since the emf induced in different slots are not in phase, their phasor sum is less than their numerical sum.
Example:
2-pole 6-slot winding with 1 slot per pole per phase: $k_d=1.0$
2-pole 12-slot winding with 2 slots per pole per phase: $k_d=0.966$
2-pole 18-slot winding with 3 slots per pole per phase: $k_d=0.96$
2-pole 24-slot winding with 4 slots per pole per phase: $k_d=0.958$
2-pole winding with an infinite number of slots per pole per phase: $k_d=0.955$
The skew factor $k_s$ reflects the fact that the winding is angularly twisted, which results in an angular spread and reduced emf.
Especially squirrel-cage induction motors have their rotor bars skewed by one slot-pitch in order to reduce the winding factor harmonics introduced by the slotting of the stator.
Slot Harmonics Define Science
According to our definition of winding factor (The winding factor for a specific winding expresses the ratio of flux linked by that winding compared to flux that would have been linked by a single-layer full-pitch non-skewed integer-slot winding with the same number of turns and one single slot per pole per phase.), the winding factor of these single-layer full-pitch non-skewed integer-slot windings with one single slot per pole per phase must be 1.0!
Examples of winding layouts that have a winding factor of 1.0:
Single-layer 2-pole 6-slot integer-slot winding.
Single-layer 4-pole 12-slot integer-slot winding.
Single-layer 6-pole 18-slot integer-slot winding.
Single-layer 8-pole 24-slot integer-slot winding.
Slot Harmonics Define Meaning
Read about another glossary term