Chapter 7: Higher Harmonics In Induction Motors
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Source Metadata
Section titled “Source Metadata”| Field | Value |
|---|---|
| Source | Theory and Calculation of Electric Apparatus |
| Year | 1917 |
| Section ID | theory-calculation-electric-apparatus-chapter-06 |
| Location | lines 12398-13955 |
| Status | candidate |
| Word Count | 3505 |
| Equation Candidates In Section | 0 |
| Figure Candidates In Section | 1 |
| Quote Candidates In Section | 0 |
Opening Source Excerpt
Section titled “Opening Source Excerpt”CHAPTER VII HIGHER HARMONICS IN INDUCTION MOTORS 88. The usual theory and calculation of induction motors, .■is discussed in '* Theoretical Elements of Electrical Enginccr- ing" and in "Theory and Calculation of Alternating-current Phenomena," is based on the assumption of the sine wave. That U, it is assumed that the voltage impressed upon the motor per phase, and therefore the magnetic flux and the current, KM sine waves, and it is further assumed, that the distribution of the winding on the circumference of the armature or primary, is sinusoidal in space. While in most eases this is sufficicntly the ease, it is not always so, and especially the space or air-gap distribution of the magnetic flux may sufficiently differ from sine shape, to exert an appreciable effect on the torque at lower speeds, and requireSource-Located Theme Snippets
Section titled “Source-Located Theme Snippets”Magnetism
Section titled “Magnetism”... .■is discussed in '* Theoretical Elements of Electrical Enginccr- ing" and in "Theory and Calculation of Alternating-current Phenomena," is based on the assumption of the sine wave. That U, it is assumed that the voltage impressed upon the motor per phase, and therefore the magnetic flux and the current, KM sine waves, and it is further assumed, that the distribution of the winding on the circumference of the armature or primary, is sinusoidal in space. While in most eases this is sufficicntly the ease, it is not always so, and especially the space or a ...Waves / transmission lines
Section titled “Waves / transmission lines”... HIGHER HARMONICS IN INDUCTION MOTORS 88. The usual theory and calculation of induction motors, .■is discussed in '* Theoretical Elements of Electrical Enginccr- ing" and in "Theory and Calculation of Alternating-current Phenomena," is based on the assumption of the sine wave. That U, it is assumed that the voltage impressed upon the motor per phase, and therefore the magnetic flux and the current, KM sine waves, and it is further assumed, that the distribution of the winding on the circumference of the armature or primary, is sinusoidal in spac ...Complex quantities
Section titled “Complex quantities”... he magnetic flux may sufficiently differ from sine shape, to exert an appreciable effect on the torque at lower speeds, and require consideration where motor action and braking action with considerable power is required throughout the entire range of speed. Let then: r — iji cos * + e» cos (3 * — a,) + es cos (5 * — at) 4- e? cos (7* - a-) + e, cos (9 * - a„) + . . . (1) be the voltage impressed u|hjn one phase of the induction motor. If the motor is a quarter-pha.se motor, the voltage of the second motor phase, which lags 90° or behind the fi ...Radiation / light
Section titled “Radiation / light”... s(3 0- «» + 5)-| (4) As seen, these also constitute a quarter-phase system of voltage, but the second wave, which is lagging in the funda- mental, is 90° leading in the third harmonic, or in other words, the third harmonic gives a backward rotation of the poles with triple frequency. It thus produces a torque in opposite direc- tion to the. fundamental, and would reach its synchronism, that is, zero torque, at one-third of synchronism in negative direction, or at the speed <S, = — J£, given in fraction of synchronous speed. For backward rotation above o ...Chapter-Local Concept Hits
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| Frequency | 8 | seeded |
Chapter-Local Glossary Hits
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Equation Candidates
Section titled “Equation Candidates”| Candidate ID | OCR / PDF-Text Candidate | Source Location |
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Figure Candidates
Section titled “Figure Candidates”| Candidate ID | OCR / PDF-Text Candidate | Source Location |
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theory-calculation-electric-apparatus-fig-058 | which represents the current distribution per phase through the air gap of the induction machine, shown by the diagrams F of Fig. 58. The corresponding flux distribution, $, in… | line 13533 |
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Modern Engineering Reading Prompts
Section titled “Modern Engineering Reading Prompts”- Magnetism: Track flux, reluctance, permeability, magnetizing force, and loss language against modern magnetic-circuit terminology.
- Waves / transmission lines: Map Steinmetz’s wave and line language onto modern distributed constants, propagation velocity, standing waves, and reflections.
- Complex quantities: Track how Steinmetz preserves geometric rotation and quadrature while translating the same operation into symbolic form.
- Radiation / light: Compare the chapter’s radiation vocabulary with modern electromagnetic radiation, spectral frequency, wavelength, absorption, and illumination engineering.
- Alternating current: Compare Steinmetz’s AC language with modern sinusoidal steady-state analysis, RMS quantities, phase, and phasor notation.
Ether-Field Interpretive Boundary
Section titled “Ether-Field Interpretive Boundary”- Magnetism: Centrifugal/divergent magnetic-field readings are interpretive overlays, not automatic historical claims.
- Waves / transmission lines: Standing/traveling wave passages may support richer field interpretations; the page keeps those readings separate from verified Steinmetz wording.
- Radiation / light: Radiation and wave language can invite ether-field comparison, but source wording, modern radiation theory, and speculative synthesis must stay separated.
Promotion Checklist
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- Verify the chapter boundary and surrounding context.
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