The document discusses DC drive systems using DC-DC converters and AC-DC converters. It covers the block diagrams and operating principles of single-quadrant, two-quadrant, and four-quadrant DC-DC converters in continuous conduction mode. It also discusses current-controlled and voltage-controlled DC drives. The key points are:
1. DC-DC converters can be single-quadrant, two-quadrant, or four-quadrant depending on whether regenerative braking and bidirectional power flow is possible.
2. Current control allows for short-circuit protection and easier speed control loop design compared to voltage control.
3. Hysteresis, carrier-based, and predictive controllers can
3. Block Diagram of DC Drives
~ Tl (s )
Ed ( s )
α (s) _ _
vD (s ) I a (s ) Te (s)
ωr (s ) + + 1 + 1 ω (s )
∑ Gω (s ) Ed ∑ Ra + sLa
Kφ ∑ sJ
_ _
Ea (s )
Kφ
ω (s ) =
(ω G ω ( s ) Ed / JLa ) ω ref ( s )
( )
o
s + sα + ω + ωo Gω ( s ) Ed / JLa
2 2
o
ωo / JLa ~
−
(
s 2 + sα + ωo + ωo Gω ( s ) Ed / JLa
2
) Ed ( s )
−
(s + α ) / J
(
s + sα + ω + ωo Gω ( s ) Ed / JLa
2 2
o ) Tl ( s )
4. Single-Quadrant DC-DC Converter
• The switching device is
MOSFET for low-power,
IGBT for medium power,
and GTO for high power
applications.
• Single-quadrant is
adequate when fast
speed reversal and
regenerative braking are
not required.
• Carrier signal is unipolar.
5. Two-Quadrant DC-DC Converter
• Regenerative braking is
possible.
• If the source cannot
accept the regenerated
energy, the energy can
be absorbed by a resistor
that is connected in the
dc side.
• Carrier signal is unipolar.
• This system is suitable for
electric vehicles.
6. Four-Quadrant
• Both output voltage
and current are
bidirectional.
• Two splitting
capacitors are
required.
• Carrier signal must be
bipolar.
7. Four-Quadrant DC-DC Converter
D1 D3
S1 vo S3 Suitable for robotic and machine
M tools
Ed S2 S4
D2 D4
S1 S2 S3 S4 Vo
ON OFF ON OFF 0
ON OFF OFF ON Ed
OFF ON ON OFF -Ed
ON OFF ON OFF 0
8. Operating Principles of
DC-DC Converters
id iL di L
R v D = Ri L + L + vo
S L dt
vo
Ed D vD 0 ≤ t < TON
vD = Ed
di L
id R
iL E d = Ri L + L + vo
dt
S L
vo TON ≤ t < Ts
Ed D vD
vD = 0
di L
0 = Ri L + L + vo
TON
vD = E d = αE d dt
Ts
9. Operating Principles
Ed Ed
T vo
vD vD = ON Ed vD
Ts
0 0
TON α1Ts α 2Ts
TON
Ts Ts
E d − vo E d − vo
vL vL
−vo − vo
iL
0
iL
id
v D = αE d
v D ≠ αE d
Continuous mode Discontinuous mode
10. Continuous Conduction Mode
• The converter can be modeled as a variable dc voltage
source or as a dc voltage amplifier.
• The gain of amplifier is equal to the dc voltage source
and the input signal is equal to the duty factor signal or
equal to reference signal (if the amplitude of the carrier
signal is equal to unity).
• In single-quadrant chopper, both output voltage and
current cannot be negative.
• In two-quadrant chopper, the output voltage cannot be
negative but the output current is bidirectional.
• In four-quadrant chopper, both output voltage and
current are bidirectional.
• Nonidealities of amplifier can be represented as
disturbance signal.
14. Continuous Conduction Mode
• Under continuous conduction mode, the
converter can be considered as a variable
dc voltage source.
• The output of dc voltage source is
proportional to the cosinus of firing angle.
• In fully controlled rectifiers, the output
voltage is bidirectional but the output
current is unidirectional.
• In four-quadrant rectifier, both output
voltage and current are bidirectional.
16. Advantages Current-Controlled DC Drives
• Short-circuit protection can be done
inherently.
• The design of speed controller is easy
• The response is faster
• The torque is proportional to the armature
current.
18. Block diagram of DC drive using
current-controlled converter
~ Tl (s )
Ed ( s )
α (s) _ _
vD (s ) I a (s ) Te (s)
ωr (s ) + + 1 + 1 ω (s )
∑ Gω (s ) Ed ∑ Ra + sLa
Kφ ∑ sJ
_ _
Ea (s )
Kφ
Voltage-controlled
Current-Controlled
19. Block Diagrams
I a (s) =
Gc ( s ) Ed
sLa + Ra + Gc ( s ) Ed
I a (s) −
ref 1
sLa + Ra + Gc ( s ) Ed
[ ~
Ea ( s ) + Ed ( s ) ]
Gω ( s ) KΦ 1
ω (s) = ωr (s) − Tl ( s )
sJ + Gω ( s ) KΦ sJ + Gω ( s ) KΦ
23. Analysis
0 → TON
dia ~
vD = Ed ia : −h → h
v D = Ra ia + La + ea
dt 2h =
(1 − α )Ed T
ON
~ La
ia = ia + ia 2hLa
~ TON =
v =v +v
D D D (1 − α )Ed
0 → TOFF
v D = Ra i a + e a = α E d ~
vD = 0 ia : h → −h
~ ~
~ ~ d ia d ia − αE d
v D = Ra ia + La ≈ La − 2h =
La
TOFF
dt dt
2hLa
TOFF =
~
ia =
1 ~
∫
v D dt =
1
∫ (v D − v D )dt αE d
La La Ts = TON + TOFF f s = 1 / Ts =
Ed
(1 − α )α
2hLa
24. Carrier based current controller
S1
Ia
Ra La
Ed
S2 ea
Ia +
ref
Current
Regulator
−
~
Current Ea ( s ) + Ed ( s )
controller _
α (s ) vD (s ) I a (s )
I a (s ) +
ref
+ 1
∑ Gω (s) Ed ∑ Ra + sLa
_
26. Predictive current controller
v D − ea
Δia = Ts
La
v D − ea
ia (k + 1) − i (k ) = Ts
La
v D = αE d =
[
La ia (k + 1) − ia (k )
ref
]+ ea
Ts
α=
[
La ia (k + 1) − ia (k ) ea
ref
+
]
Ts E d Ed
34. Block Diagram of DC Drives Using
AC-DC Converter
AC source
cosα α Converter and
−1
cos DC output
pulse gate generator
6 fLs I o
−
α +
cosα cos −1 3 2
Vll cos
π Vo
6 fLs I o
−
cosα +
3 2
Vll
π Vo
35. Current-Controlled Rectifier
AC source
Io
R L
ref +
Io cosα α Converter and
Current
cos−1 E
Controller pulse gate generator
−
Ns
−
ref +
Io Current
cosα + 1 Io
3 2
Vll
Controller π sL + R
− −
6 fLs
42. DC Drive Considerations
• The input power factor is decreased when the speed is
reduced.
• The input current is rich in harmonics. The dominant
harmonics are 5th and 7th order when three-phase six-
pulse rectifier is used.
• The converter generates notches in the input voltage.
• Additional losses due to current ripple.
• Separate fan must be provided when operating speed is
low.
• The dc motor cannot be operated under stalled
conditions for a long time.
• Comutator and brushes make the dc drive cannot be
designed for very high speeds.
44. Tugas
Rancanglah pengendali kecepatan motor arus searah penguatan bebas (data ambil di
literatur) 4-kuadran sebagai berikut:
1) Konverter dc-dc 4-kuadran dengan pengendali arus hysteresis dan pengendali
kecepatan PI.
2) Konverter dc-dc 4-kuadran dengan pengendali arus hysteresis dan pengendali
kecepatan IP.
3) Konverter dc-dc 4-kuadran dengan pengendali arus PI dan pengendali kecepatan
PI.
4) Konverter dc-dc 4-kuadran dengan pengendali arus PI dan pengendali kecepatan
IP.
5) Konverter thyristor ac-dc 4-kuadran dengan pengendali arus PI dan pengendali
kecepatan PI.
6) Konverter thyristor ac-dc 4-kuadran dengan pengendali arus PI dan pengendali
kecepatan IP.