Chapter 4: Induction Motor With Secondary Excitation
Research workbench, not a finished commentary page.
This page is generated from processed source text and candidate catalogs. It exists to help researchers decide what to verify, promote, and deeply decode next.
Source Metadata
Section titled “Source Metadata”| Field | Value |
|---|---|
| Source | Theory and Calculation of Electric Apparatus |
| Year | 1917 |
| Section ID | theory-calculation-electric-apparatus-chapter-03 |
| Location | lines 5555-8554 |
| Status | candidate |
| Word Count | 9778 |
| Equation Candidates In Section | 74 |
| Figure Candidates In Section | 1 |
| Quote Candidates In Section | 0 |
Opening Source Excerpt
Section titled “Opening Source Excerpt”CHAPTER IV INDUCTION MOTOR WITH SECONDARY EXCITATION 38. While in the typical synchronous machine and eommu- tating machine the magnetic field is excited by a direct current, characteristic of the induction machine is, that the magnetic field is excited by an alternating current derived from the alter- nating supply voltage, just as in the alternating-current trans- former. As the alternating magnetizing current is a wattless reactive current, the result is, that the alternating-current input into the induction motor is always lagging, the more so, the larger a part of the total current is given by the magnetizing current. To secure good power-factor in an induction motor, the magnetizing current, that i«, the current which produces the magnetic field flux, must be kept as small as possible. This means as small an air gap between statorSource-Located Theme Snippets
Section titled “Source-Located Theme Snippets”Impedance / reactance
Section titled “Impedance / reactance”... secured, power-factor and apparent efficiency necessarily are very low. As illustration is shown in Fig. 20 the load curve of a typical 100-hp. 60-cycle 80-polar induction motor (90 revolutions per minute) of the constants: Impressed voltage: ea = 500. Primary exciting admittance: Ya = 0.02 — 0.6 j. Primary self-inductive impedance: Zu = 0.1 + 0.3j. Secondary self-inductive impedance: Zi = 0.1 + 0.3 j. INDUCTION MOTOR 53 As seen, at full-load of 75 kw. output, the efficiency is 80 per cent., which is fair for a slow-speed motor. But the p ...Radiation / light
Section titled “Radiation / light”... primary, that is, which receives electric power and converts it into mechanical power, and the primary or stator of the induc- tion machine thus corresponds to the armature of the synchro- nous or commutating machine. In the secondary or rotor of the induction machine, low-frequency currents — of the frequency of slip — are induced by the primary, but the magnetic field flux is produced by the exciting current which traverses the primary or armature or stator. Thus the induction machine may be considered as a machine in which the magnetic field is produ ...Field language
Section titled “Field language”CHAPTER IV INDUCTION MOTOR WITH SECONDARY EXCITATION 38. While in the typical synchronous machine and eommu- tating machine the magnetic field is excited by a direct current, characteristic of the induction machine is, that the magnetic field is excited by an alternating current derived from the alter- nating supply voltage, just as in the alternating-current trans- former. As the alternating magnetizing current is ...Dielectricity / capacity
Section titled “Dielectricity / capacity”... ow, that is, the number of poles large compared with the out- put, and the pole pitch thus must for economical reasons be kept small — as for instance a 100-hp. 60-cycle motor for 90 revolu- tions, that is, 80 poles— or where the requirement of an exutMrVV momentary overload capacity has to be met, etc. In such motors of necessity the exciting current or current at no-load — which is practically all magnetizing current — is a very large part of full-load current, and while fair efficiencies may nevertheless be secured, power-factor and apparent efficienc ...Chapter-Local Concept Hits
Section titled “Chapter-Local Concept Hits”| Concept Candidate | Hits In Section | Status |
|---|---|---|
| Frequency | 70 | seeded |
| Light | 4 | seeded |
Chapter-Local Glossary Hits
Section titled “Chapter-Local Glossary Hits”| Term Candidate | Hits In Section | Status |
|---|---|---|
| No chapter-local term hits yet | - | - |
Equation Candidates
Section titled “Equation Candidates”| Candidate ID | OCR / PDF-Text Candidate | Source Location |
|---|---|---|
theory-calculation-electric-apparatus-eq-candidate-0227 | small — as for instance a 100-hp. 60-cycle motor for 90 revolu- | line 5579 |
theory-calculation-electric-apparatus-eq-candidate-0228 | Impressed voltage: ea = 500. | line 5592 |
theory-calculation-electric-apparatus-eq-candidate-0229 | Primary exciting admittance: Ya = 0.02 — 0.6 j. | line 5594 |
theory-calculation-electric-apparatus-eq-candidate-0230 | Primary self-inductive impedance: Zu = 0.1 + 0.3j. | line 5596 |
theory-calculation-electric-apparatus-eq-candidate-0231 | Secondary self-inductive impedance: Zi = 0.1 + 0.3 j. | line 5598 |
theory-calculation-electric-apparatus-eq-candidate-0232 | Y0 = 0.01 -O.lj, | line 5616 |
theory-calculation-electric-apparatus-eq-candidate-0233 | 1. Passing a direct current through the rotor for excitation. | line 5736 |
theory-calculation-electric-apparatus-eq-candidate-0234 | effective frequency,/ — (1 — s) / = sf, that is, the frequency of | line 5748 |
Figure Candidates
Section titled “Figure Candidates”| Candidate ID | OCR / PDF-Text Candidate | Source Location |
|---|---|---|
theory-calculation-electric-apparatus-fig-022 | nes, the ) parent Fig. 22. INDUCTION MOTOR 67 | line 6685 |
Hidden-Gem Quote Candidates
Section titled “Hidden-Gem Quote Candidates”| Candidate ID | Candidate Passage | Source Location |
|---|---|---|
| No chapter-local candidates yet | - | - |
Modern Engineering Reading Prompts
Section titled “Modern Engineering Reading Prompts”- Impedance / reactance: Translate historical opposition terms into modern impedance, admittance, conductance, susceptance, and complex-plane notation.
- Radiation / light: Compare the chapter’s radiation vocabulary with modern electromagnetic radiation, spectral frequency, wavelength, absorption, and illumination engineering.
- Field language: Read for whether field language is mechanical, geometrical, causal, descriptive, or simply a convenient engineering model.
- Dielectricity / capacity: Check whether the passage treats capacity, condensers, displacement, or dielectric stress as field storage rather than only circuit algebra.
- Magnetism: Track flux, reluctance, permeability, magnetizing force, and loss language against modern magnetic-circuit terminology.
Ether-Field Interpretive Boundary
Section titled “Ether-Field Interpretive Boundary”- Radiation / light: Radiation and wave language can invite ether-field comparison, but source wording, modern radiation theory, and speculative synthesis must stay separated.
- Field language: Field-pressure or field-gradient interpretations can be explored here only after the explicit source passage and modern engineering translation are kept distinct.
- Dielectricity / capacity: A Wheeler-style reading may emphasize dielectric compression, field stress, and stored potential, but this page treats that as interpretation unless Steinmetz explicitly says it.
- Magnetism: Centrifugal/divergent magnetic-field readings are interpretive overlays, not automatic historical claims.
Promotion Checklist
Section titled “Promotion Checklist”- Open the full source text and the scan or raw PDF.
- Verify the chapter boundary and surrounding context.
- Promote exact quotations only after checking the source image.
- Move mathematical candidates into canonical equation pages only after formula typography is corrected.
- Move diagram candidates into the diagram archive only after image extraction, crop verification, and manifest creation.
- Keep Steinmetz wording, modern translation, and ether-field interpretation in separate labeled layers.