TIDUES0E June 2019 – April 2024 TMS320F28P550SJ , TMS320F28P559SJ-Q1
High-resolution features used:
The PWM pulses of the secondary side
are phase-shifted with respect to the PWM pulses of the primary. Controlling the
phase shift enables transfer of power between the primary and secondary and vice
versa. The maximum power transferred is very sensitive to the value of phase shift
in a Dual Active Bridge. A small series inductor can lead to maximum power transfer
at a small value of phase shift. Since the range over which the phase shift is going
to be varied is small, and accurate control requires fine increment and decrement
steps of phase. The phase control is implemented using Hi-Res (high resolution)
feature of F28004x. The function
DAB_calculatePWMDutyPeriodPhaseShiftTicks()
inside ISR1
calculates the required the required high resolution phase control for both voltage
and current mode control. This helps in handling sudden load changes smoothly
without producing huge overshoots/transients in the current waveforms.
The variable
DAB_phaseSyncPrimToSecCountDirection
is updated to control the
forward mode or reverse mode of power flow.