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3.5
Controlling Multiple Half H-Bridge (HHB) Converters
CTR=zero
CTR=CMPB
X
En
SyncOut
Phase reg
Ext SyncIn
(optional)
EPWM1A
EPWM1B
SyncOut
Phase reg
CTR=CMPB
CTR=zero
X
En
EPWM2B
EPWM2A
Slave
Master
V
out1
EPWM1A
SyncIn
SyncIn
V
DC_bus
EPWM1B
EPWM2B
EPWM2A
V
DC_bus
V
out2
Φ
=0
°
Φ
=0
°
Controlling Multiple Half H-Bridge (HHB) Converters
Topologies that require control of multiple switching elements can also be addressed with these same
ePWM modules. It is possible to control a Half-H bridge stage with a single ePWM module. This control
can be extended to multiple stages.
ePWM modules. It is possible to control a Half-H bridge stage with a single ePWM module. This control
can be extended to multiple stages.
shows control of two synchronized Half-H bridge stages
where stage 2 can operate at integer multiple (N) frequencies of stage 1.
shows the waveforms
generated by the configuration shown in
Module 2 (slave) is configured for Sync flow-through; if required, this configuration allows for a third Half-H
bridge to be controlled by PWM module 3 and also, most importantly, to remain in synchronization with
master module 1.
bridge to be controlled by PWM module 3 and also, most importantly, to remain in synchronization with
master module 1.
Figure 3-7. Control of Two Half-H Bridge Stages (F
PWM2
= N x F
PWM1
)
78
Applications to Power Topologies
SPRU791D – November 2004 – Revised October 2007