1. Single shunt phase shift overview
In the context of a single shunt topology, the purpose of the phase shifting is to shift one or two duty cycles in order to have to be able to sample current signal in the boundary zones instead of inserting a distortion window. The benefit are:
- Less commutations
- Less switching losses
- Less acoustical noise
- Better current shape
2. Single shunt phase shift comparison
- Single shunt with distortion window
- Single shunt with phase shift
- and Three shunts
3. Phase shift principle
Boundary zone 1:
- FW shifts on the right the smallest duty cycle by TMIN (minimum window time for sampling)
Boundary zone 2:
- FW shifts on the right the middlest duty cycle by TMIN (minimum window time for sampling)
Boundary zone 3:
- FW shifts on the right the smallest duty cycle and on the left the highest duty cycle by TMIN (minimum window time for sampling)
4. Peripheral usage
Phase shifting needs the following peripherals to create the shifting. According to the advanced timer capabilities, one or two DMA channels will be used
MCU | TIM | DMA | IRQ |
---|---|---|---|
F0 | Example | Example | Example |
G0 | Example | Example | Example |
F3 | Example | Example | Example |
Example | Example | Example | |
F4 | Example | Example | Example |
Example | Example | Example | |
G4 | Example | Example | Example |
Example | Example | Example | |
L4 | Example | Example | Example |
Example | Example | Example | |
F7 | Example | Example | Example |
Example | Example | Example |
5. Single shunt phase shift scheduling
6 channels advanced timer and execution rate = 1 (G0,G4,F3,L4,F7)
6 channels advanced timer and execution rate = 2 (G0,G4,F3,L4,F7)
4 channels advanced timer and execution rate = 1 (F4)
4 channels advanced timer and execution rate = 2 (F4)
4 channels advanced timer and execution rate = 2 (F0)
6. Single shunt phase shift in the MCSDK
Single shunt is divided in 4 template files
- r1_ps_pwm_fdbk.c/.h.ftl processed when the MC project uses a MCU with 6 channels advanced timer (G0,F3,G4,L4,F7)
- r1_ps_4ch_pwm_fdbk.c/.h.ftl processed when the MC project uses a MCU with 4 channels advanced timer