Rotational Linear Velocity Acceleration Motion Angular Velocity Angular

• Slides: 64

Rotational • Linear Velocity • Acceleration Motion . Angular Velocity . Angular

Newton’s Law of Rotation (force applied) (perpendicular distance) (Fig 1 -2. ) (J: moment of Inertia. )

Magnetic Field 磁場 安培定律是說明電流產生磁場的基本定律。 • Ampere’s Law I • Magnetic Field Intensity H

Magnetic Flex Φ, B • Magnetic Flex Φ • Magnetic Flex Density B

EX 1 -2 given : B, N, R find: R, Ф, I

EX 1 -3 given : N, I, R find: R, Ф

1. 6 Induced Force on a wire Motor action I

1. 7 Induced Voltage + _

1. 8 the Linear DC Machine Fig 1 -19.

Starting the DC Machine

Linear DC Machine Behaves: 1. At Start: 2. Force: 3. Accelerate: 4. Reduce I : 5. Decrease F: 6. At F=0; 7. Move at a constant speed

Linear DC Machine as a Motor: is applied to the bar: 1. 2. 3. 4. 5. Bar begins to slow down, Induced voltage drops Decrease current: Increase Until; Fig 1 -23

Linear DC Machine as a Generator 1. Applied force (right) , 2. Increase Velocity v 3. Induced Voltage 4. With 5. Current 6. Induced force 7. 8. , (Battery is charging)

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DC Machine

DC Machinery Fundamentals

DC Gen

DC & AC Gen

DC Generator

The Induce Torque

Structure

Ex 8 -1 Give: a. Switch closed Steady state:

C. load torque is applied ; 1. Speed decrease: …………………. 2. Rotor current: …………… 3. 4. until:

Power supplied to the shaft: Power out of battery:

d. A Torque Is Applied in Direction of Motion , a. The rotor accelerates ; Speed increase

D b. c. d. (charge)

DC machine basics(換相 ) X X Force South pole X Angular velocity X Zero Force North pole

Basic theory

8. 2 Commutation (2 P) 折疊 波繞

Lap-wound A lap winding is m-plax; Pitch: Current path: 折疊

Lap-Wound

The Wave Winding Pitch: Multiplex wave C is the number of coil on the rotor. Current path:

8. 4 Problems With Commutation Armature Reaction Neutral-plane shift a. Arcing and sparking b. Total average flux is decrease flux weakening. (8 -24 8 -25) Voltage will be induced in the …. commutation segment.

Armature Reaction

Solutions to the Problems With Commutation Three approaches have been developed to correct the problems of armature reaction and voltage. 1. Brush shift(depend on load; G; M 2. Commutating poles or interpoles 3. Compensating winding )

Basic theory

Ex 3. 3

Ex 3. 4

Ex 3. 4 b

Ex 3. 4 c

Losses Generator Motor

Voltage Regulation