Electrical Engineering

Power Electronics

1

Introduction to Power Electronics

by D. W. Hart

Chapter 5. AC to AC Converters

Electrical Engineering

Power Electronics

2

THE SINGLE-PHASE AC VOLTAGE CONTROLLER

2 m

o,rms m

sin 2V1V V sin t d t 1

22

RMS OUTPUT VOLTAGE

Electrical Engineering

Power Electronics

3

OUTPUT VOLTAGE VS. DELAY ANGLE

Electrical Engineering

Power Electronics

4

SINGLE-PHASE CONTROLLER WITH AN R-L LOAD

Electrical Engineering

Power Electronics

5

wt 2

Van Vbn Vcn

0

02

6

3

6

4

6

5

6

7

6

8

6

9

6

10

6

11

6

6

2

Gs1

Gs2

Gs3

Gs4

Gs5

Gs6

Gs1

Gs2

Gs3

Gs4

Gs5

Gs6

wt 2

VanVab/2 Vac/2

0

02

6

3

6

4

6

5

6

7

6

8

6

9

6

10

6

11

6

6

2

Electrical Engineering

Power Electronics

6

van for 0 < α < 60° (α = 30° shown)

THREE-PHASE VOLTAGE CONTROLLERS (Y-Connected Resistive Load)

Electrical Engineering

Power Electronics

7

Electrical Engineering

Power Electronics

8

Delta-Connected Resistive Load