Chapter 1: Speed Control Of Induction Motors
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-01 |
| Location | lines 1368-3542 |
| Status | candidate |
| Word Count | 6386 |
| Equation Candidates In Section | 90 |
| Figure Candidates In Section | 0 |
| Quote Candidates In Section | 0 |
Opening Source Excerpt
Section titled “Opening Source Excerpt”CHAPTER I SPEED CONTROL OF INDUCTION MOTORS I. STARTING AND ACCELERATION 1. Speed control of induction motors deals with two problems: to produce a high torque over a wide range of speed down to standstill, for starting and acceleration; and to produce an approximately constant speed for a wide range of load, for constant-speed operation. In its characteristics, the induction motor is a shunt motor, that is, it runs at approximately constant speed for all loads, and this speed is synchronism at no-load. At speeds below full speed, and at standstill, the torque of the motor is low and the current high, that is, the starting-torque efficiency and especially the apparent starting-torque efficiency are low. Where starting with considerable load, and without excessive current, is necessary, the induction motor thus requires the use of aSource-Located Theme Snippets
Section titled “Source-Located Theme Snippets”Radiation / light
Section titled “Radiation / light”... 10; Yt-g-jb" 0.01 - 0.1 j; Zo = r„+ j"j:0 =0.1 +0.3j; Z, = rl+jxl = 0.1 -f 0.3j; the speed-torque curve of this motor is shown as A in Fig. 1 SPEED CONTROL 3 Suppose now a resistance, r, i8 inserted in series into the sec- ondary circuit, which when cold — that is, at light-load — equals the internal secondary resistance: but increases so as to double with 100 amp. passing through it. This resistance can then be represented by: r = r° (1 + i,« 10-*) = 0.1 (1 +»i,10-4), NDUCTION MOTOR -110 I ^ z,=r, + .3i SPEED CONTROL BY POSITI ...Impedance / reactance
Section titled “Impedance / reactance”... actor, in a closed magnetic circuit, are independent of the frequency, and vary relatively little with the magnetic density and thus the current, over a wide range,1 thus may approxi- mately be assumed as constant. That is, the hysteretic con- ductance is proportional to the susceptance : g' = V tan a. ((>) Thus, the exciting admittance, of a closed magnetic circuit of negligible resistance and negligible eddy-current losses, at the frequency of slip, «, is given by: Y' = g' - jb' = V (tan a - j) = - J = (tan a - j) (7) 8 8 8 1 "Theoiy and Calcula ...Magnetism
Section titled “Magnetism”... sistance with increas- ing slip, to get high torque at low speeds, the same result can be produced by the use of an effective resistance, such as the effect- ive or equivalent resistance of hysteresis, or of eddy currents. As the frequency of the secondary current varies, a magnetic circuit energized by the secondary current operates at the varying frequency of the slip, s. At a given current, i\, the voltage required to send the current through the magnetic circuit is proportional to the frequency, that is, to 8. Hence, the suaceptance is inverse pro ...Dielectricity / capacity
Section titled “Dielectricity / capacity”... hunt character- istic, except that its speed is limited by synchronism. Series resistance in the armature thus is not suitable to produce steady running at low speeds. To a considerable extent, this disadvantage of inconstancy of speed can be overcome: (a) By the use of capacity or effective capacity in the motor secondary, which contracts the range of torque into that of approximate resonance of the capacity with the motor inductance, and thereby gives fairly constant speed, independent of the load, at various speed values determined by the value o ...Chapter-Local Concept Hits
Section titled “Chapter-Local Concept Hits”| Concept Candidate | Hits In Section | Status |
|---|---|---|
| Frequency | 28 | seeded |
| Light | 5 | 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-0001 | 2. A resistance material of high positive temperature coeffi- | line 1435 |
theory-calculation-electric-apparatus-eq-candidate-0002 | r = r° (1 + aii3). (I) | line 1449 |
theory-calculation-electric-apparatus-eq-candidate-0003 | Co = 110; | line 1454 |
theory-calculation-electric-apparatus-eq-candidate-0004 | Zo = r„+ j”j:0 =0.1 +0.3j; | line 1457 |
theory-calculation-electric-apparatus-eq-candidate-0005 | Z, = rl+jxl = 0.1 -f 0.3j; | line 1458 |
theory-calculation-electric-apparatus-eq-candidate-0006 | Suppose now a resistance, r, i8 inserted in series into the sec- | line 1464 |
theory-calculation-electric-apparatus-eq-candidate-0007 | but increases so as to double with 100 amp. passing through it. | line 1469 |
theory-calculation-electric-apparatus-eq-candidate-0008 | r = r° (1 + i,« 10-*) | line 1472 |
Figure Candidates
Section titled “Figure Candidates”| Candidate ID | OCR / PDF-Text Candidate | Source Location |
|---|---|---|
| No chapter-local candidates yet | - | - |
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”- Radiation / light: Compare the chapter’s radiation vocabulary with modern electromagnetic radiation, spectral frequency, wavelength, absorption, and illumination engineering.
- Impedance / reactance: Translate historical opposition terms into modern impedance, admittance, conductance, susceptance, and complex-plane notation.
- Magnetism: Track flux, reluctance, permeability, magnetizing force, and loss language against modern magnetic-circuit terminology.
- Dielectricity / capacity: Check whether the passage treats capacity, condensers, displacement, or dielectric stress as field storage rather than only circuit algebra.
- Hysteresis: Compare the passage with modern magnetic loss, B-H loop area, lag, material memory, and empirical loss laws.
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.
- Magnetism: Centrifugal/divergent magnetic-field readings are interpretive overlays, not automatic historical claims.
- 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.
- Hysteresis: An interpretive reading can treat hysteresis as field lag or memory, but the historical claim must remain Steinmetz’s actual magnetic-loss treatment.
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.