Diode Rectifiers Mohamed Abdelrahem Institute for Electrical Drive

Diode Rectifiers Mohamed Abdelrahem Institute for Electrical Drive Systems and Power Electronics Technical University of Munich Mohamed. abdelrahem@tum. de Room: 1902 Mohamed Abdelrahem Exercise: Diode rectifiers. 1

Diode p–n junction Light-emitting diode Photodiode Schottky diode (LED) Mohamed Abdelrahem Exercise: Diode rectifiers. 2

Power Electronics Applications DC signal AC signal Mohamed Abdelrahem Exercise: Diode rectifiers. 3

Diode Anode Cathode p n Higher voltage drop due to the ohmic part. Breakdown voltage Threshold voltage Mohamed Abdelrahem Exercise: Diode rectifiers. 4

Diode • Average value For one cycle For half cycle Mohamed Abdelrahem Exercise: Diode rectifiers. 5

Diode • Root mean square (RMS) Mohamed Abdelrahem Exercise: Diode rectifiers. 6

Rectifier Circuits • One-way circuits (M 1, M 2, and M 3). Mohamed Abdelrahem Exercise: Diode rectifiers. 7

Rectifier Circuits • Two-way circuits (B 2 and B 6). • Comparsion between one- and two-way circuits. Mohamed Abdelrahem Exercise: Diode rectifiers. 8

M 1 Circuit • Circuit diagram Half wave rectifier • For resistive load DC output AC signal Mohamed Abdelrahem Exercise: Diode rectifiers. 9

M 1 Circuit Mohamed Abdelrahem Exercise: Diode rectifiers. 10

M 1 Circuit Smoothing voltage Smoothing current Mohamed Abdelrahem Exercise: Diode rectifiers. 11

M 1 Circuit The diod’s maximum reverse voltage The ideal DC voltage, i. e. the average value of the rectified voltage, can be calculated as follows: Mohamed Abdelrahem Exercise: Diode rectifiers. 12

M 1 Circuit Why a transformer is used in the rectifier circuits? RMS values DC average values Mohamed Abdelrahem Exercise: Diode rectifiers. 13

M 1 Circuit Pure R load The ratio between the transformer power rating and the power in the DC part is The transformer power rating has to be more than three times greater than the power in the DC part if a pure resistive load is considered! Mohamed Abdelrahem Exercise: Diode rectifiers. 14

M 2 Circuit Mohamed Abdelrahem Exercise: Diode rectifiers. 15

M 2 Circuit V_supply = 115 v rms Mohamed Abdelrahem Exercise: Diode rectifiers. 16

M 2 Circuit Mohamed Abdelrahem Exercise: Diode rectifiers. 17

M 2 Circuit Mohamed Abdelrahem Exercise: Diode rectifiers. 18

M 2 Circuit The diod’s maximum reverse voltage The ideal DC voltage, i. e. the average value of the rectified voltage, is: Mohamed Abdelrahem Exercise: Diode rectifiers. 19

B 2 Circuit Mohamed Abdelrahem Exercise: Diode rectifiers. 20

B 2 Circuit Mohamed Abdelrahem Exercise: Diode rectifiers. 21

B 2 Circuit Mohamed Abdelrahem Exercise: Diode rectifiers. 22

B 2 Circuit Mohamed Abdelrahem Exercise: Diode rectifiers. 23

B 2 Circuit The ideal DC voltage, i. e. the average value of the rectified voltage, is: The diode’s maximum reverse voltage Mohamed Abdelrahem Exercise: Diode rectifiers. 24

Three-phase circuits M 3 circuit Mohamed Abdelrahem Exercise: Diode rectifiers. 25

M 3 circuit Mohamed Abdelrahem Exercise: Diode rectifiers. 26

M 3 circuit Mohamed Abdelrahem Exercise: Diode rectifiers. 27

M 3 circuit Mohamed Abdelrahem Exercise: Diode rectifiers. 28

M 3 circuit Vs is the rms value of the line-neutral. Vv is the rms value of the line-line voltage. The diode’s maximum reverse voltage The ideal DC voltage, i. e. the average value of the rectified voltage, is: Mohamed Abdelrahem Exercise: Diode rectifiers. 29

B 6 circuit Mohamed Abdelrahem Exercise: Diode rectifiers. 30

B 6 circuit Three-phase voltages waveforms Mohamed Abdelrahem Exercise: Diode rectifiers. 31

B 6 circuit Output Dc voltage and current Mohamed Abdelrahem Exercise: Diode rectifiers. 32

B 6 circuit Current of the Diodes Mohamed Abdelrahem Exercise: Diode rectifiers. 33

B 6 circuit Mohamed Abdelrahem Exercise: Diode rectifiers. 34

B 6 circuit Mohamed Abdelrahem Exercise: Diode rectifiers. 35

B 6 circuit The ideal DC voltage, i. e. the average value of the rectified voltage, is: The diode’s maximum reverse voltage is Mohamed Abdelrahem Exercise: Diode rectifiers. 36

Question Thank you for your attention Mohamed Abdelrahem Exercise: Diode rectifiers. 37