- BMSBattery S series
- BMSBattery S06S
- S06ST (torque sensor version)
- S06S-BL (Bluetooth version)
- PWM signals
- Phase B current signal
- BMSBattery S06SC
- BMSBattery S12S
- BMSBattery bottle battery controller
- LCD control panel
- Kunteng mobile app
- How to open the controller and solder the programming header
- Hardware mods
- Other controllers
- BMSBattery S06P
- Kunteng 18 mosfets motor controller
- Lishui motor controllers
- JinHui motor controllers
- Step-by-step tutorial development tools
- C library
- Other tools
- Torque speed
- Motor control scheme of S06S controller
- BLDC 6 steps
- PWM schemes
- So, Which PWM Technique is Best? (Part 1)
- So, Which PWM Technique is Best? (Part 2)
- So, Which PWM Technique is Best? (Part 3)
- So, Which PWM Technique is Best? (Part 4)
- So, Which PWM Technique is Best? (Part 5)
- So, Which PWM Technique is Best? (Part 6)
- So, Which PWM Technique is Best? (Part 7)
- PWM control and Dead Time Insertion
- Low inductance motors
- Throttle Control Modes
- Phase angle FOC
- PWM frequency VS motor eRPM
- Sinusoidal Control of BLDCM with Hall Sensors Based
- Self-Learn Hall Sensor Calibration Mode
- STM8S105 Alternatives
- PID algorithm - negative output values
- Endless-sphere.com forum messages
- 2017.04.25 - Initial forum message
- 2017.05.08 - First flash and debug on a dev board
- 2017.05.18 - First code flashing and running
- 2017.05.20 - more new information
- 2017.08.23 - SxxP versus SxxS versus LSW-675
- 2017.09.01 - Trying to figure out an algorithm to automatically adjust ui8_position_correction_value
- 2017.09.02 - How to do FOC on the BMSBattery S06S/Kunteng STM8 motor controllers
- 2017.09.03 - more ideas about zero crossing for FOC
- 2017.09.05 - measuring IQ current and manually adjusting position_correction_value
- 2017.09.15 - our OpenSource firmware efficiency compared to Lishui 12 FET FOC
- 2017.09.19 - measuring motor current
- 2017.10.23 - FOC and no FOC comparison
- 2018.01.10 - How to measure FOC_READ_ID_CURRENT_ANGLE_ADJUST
- 2018.02.20 - Reading motor phase current from the DC link current (shunt)
2018.02.20 - Reading motor phase current from the DC link current (shunt)
Following the application note:
|Linked file: AN2267 - Implementation of current regulator for BLDC motor control with ST7FMC.pdf|
|Linked file: en.stsw-st7045.zip|
it should be possible to read motor phase current with “satisfactory results” from DC link current (shunt current).
The PWM interrupt code was changed so the interrupt always happen at the middle of current pulse. The ADC channel 6 reads the pulse value at start of interrupt and after all the other ADC channels are read.
Note the line debug_pin_set (); that is when ADC channel 6 read happens and will enable a digital pin so we can see on the oscilloscope.
And on oscilloscope, blue line is the digital pin signal used for debug and as we can see, the pulse (yellow line) is read by the ADC right on the middle.
Yellow line is shunt voltage (after amplification).
The next pictures show different current values and that signal is always read at middle.
Note that the firmware only reads 1 pulse every PWM cycle while there are 2 pulses every PWM cycle.
And log from real values:
Example of point on the graph:
- duty_cycle: 85 (33%)
- battery current (green line): 82
- motor phase current (purple line): 100
- lab power supply was measuring 2.5 amps
1. Battery current was 2.5 amps. The green line had a value of 83, which is a delta of 8 (83 - 75, where 75 is the ADC value for 0 amps), so every ADC step is 2.5/8 = 0.31 amps.
2. The motor phase current had a delta of 25 (100 - 75), which represents a value of 25*0.31= 7.75 amps.
3. The mathematical model says that: battery current = duty_cycle * motor phase current. As the duty_cycle was 33%, so the motor phase current should be (battery current / 0.33) = 2.5/0.33 = 7.6 amps <--- the measured values seems to be inline with the mathematical model.