Only a person with a great understanding can make complex things explain as simple as possible! Nice video Prof.! One question, you've mentioned R, L components, why left out C, because in this case it can be neglected? every wire has the L, R, C components
Hi, I had a glimpse of a question by you about motor star connection? Somehow it disappeared. If relevant please post again. And BTW, if not a member of the group please join: www.linkedin.com/groups/13606756 Best
How do I pick carrier frequency for the PWM signal used to control acceleration/brake regen? I have been building a custom driver and so far the motor spins the best at around 500hz, but not significantly better than at 350, 1200 and 16000 khz (PWM carrier frequencies). At 350hz carrier frequency the rotor speed, stator heat and unloaded power draw is the worst (probably too much short circuit load during the current recirculation period, as I think it goes in the equivalent of dis-continuous conduction mode). Changing the PWM signal duty cycle successfully alters the rotor speed and under about 30% PWM signal duty cycle the idle power consumption sharply drops. Advancing the hall sensor timing angle slightly helps with rotor speed and torque is reduced (as expected), but does nothing to help unloaded power draw.
For me thunderstruck moment was learning inverter stage as buck and boost converter. Its was really really helpful Sir. U r awesome for the humanity. Got some confusion in feild weakening about injecting out of phase Vin for short period...does that mean reducing the pwm pulses or average forward voltage?
Amazing presentation, especially the regen braking section explaining the natural occurrence of a boost converter without dedicated components. A thing I have been wondering is why do basic brushed motors have one north-south pole pair per 360 electrical degress (2 magnets-1 north+1 south on the side, 3 coils on the rotor) vs brushless motors having double the magnetic pole count (12 magnetic poles-6 north south pairs on the rotor, 9 coils on the stator)? Is it related to the detection of the zero-crossing point or just a way to increase the motor torque within the same manufacturing complexity of the stator?
Thanks for the presentation Professor! In d-q axis, when rotor flux is aligned with d-axis, stator flux has to be aligned with q-axis(i_d= 0) for max torque per ampere. For field weakening, we orient "i" vector so that i_d < 0. In abc-axis , this means that? In order to achieve maximum torque per ampere, we need to align the EMF and current of the phase. When we want to achieve field weakening and increase the speed, we just decrease the current amplitude (to decrease the torque) and impose a phase-shift between to the current and EMF?
It is the way around. What matters is the actual physical 3 phase vecror space while the d-q is just a mathematical manipulation limited to balanced systems and no higher harmonics.
while PWM ing the on phase there are those large voltage spikes on that coil would adding capacitors between it and the grounded input help or just make things worse? ( I was thinking about capacitors that are non polarised between each phase s? Also at what frequency does the 6 step operation work at? what about the phase PWM? (I know this one depends a lot on engine inductance but is there a x where if you go higher then it you should be fine?) while the active PHASE is PWM ed are there moments when both the active phase and the ground phase are bot connected to GND or is the PWM ed active phase left to float?
Thankyou for such a simple explanation for such a complicated control.It would be helpful if you could make a video with live implementation using a microcontroller 😊
@@sambenyaakov I made this driver without a micrcontroller and it works pretty well th-cam.com/video/3iMqkmQMQTY/w-d-xo.html However, it requires a lot of manual adjustments to operate it. I would like to automate the adjustments without a microcontroller. I understand in principal how a closed loop works with a microcontroller, but I have no idea how to automate these adjustments without a MC. Where and how would I apply feedback with discrete components?
Do we actually need a back emf if we replace a bldc motor I mean does the back emf needs to be implemented if e make equivalant circuit, i try to test the motorcontrollers current and will measure if the commutation is going the right direction when controlling it, but does back emf have a lot of effect on tbis commutation?
I try to test the motorcontrollers DRV835x but I dont want to use the motor, i will replace the motor with his equivalant. So i will generate the -Load(with my specific Resistor and Coil Value)(generate load stepwise) -back emf with a variable trapezium voltage generator -hall sensor simulation to simulate the hall sensors so actually the motorcontrollers thinks there is a turning motor but there is not. - this is done due to functional testing of the motorcontroller currents and see the commutation are going to the right direction. So my question is I want to understand better the presense of back emf in the application, do I really need to realise it. Thankyou very much.
Prof. I.m studying a mechanic but highly interesting in Electromagnetic/motors and I really in need for a professional advice about an issue of the Flux...May I get your business email or if kindly drop me a line on Seagull7@live.co.uk And I.l get back to you. Thanks in advance.
In an induction motor the current change direction constantly and a supposed rotating magnetic field is producted that the rotor chases. In a bldc motor you have to change the polarity in the coils by various means and frequency to pull and to push preferably right? and of course one pair of coils to do nothing and so on. I sure also like to know the details about coil winding in terms of resistance and number of winding turns. I seem to have a motor that appear to have lots of windings as such that it reads 100 ohm between each three legs (u,v,w) but most bldc motors are lik from 5-10 ohms..... This motor also have hall and pwm
@@sambenyaakov Thank you for your reply. . I am not sure what wires from my breaker box goes to the three wires in the above motor. With its resistance of the coils wires being high, I would think 240 V supply, having two wires and the motor with 3 wires, would I need to use a capacitor with certain uF specification? I don't have 3 phase supply at the house. This is the motor but the spec on it with regard to voltage supply is for its control board which I don't think work any more. On the motor hook up as you can see has the 3 wires for the motor and the hall 5 wires. www.h-mac.com/amana-0131p00029S.html Here is another motor I have. I am not sure if you have seen. These motors are in washing machines, the are typically a foot in diameter, with the magnet rotor being on the outside.. BLDC, three wires and hall sensor. The resistance between their 3 coil wires are 5 -6 ohms big difference with the above motor. What voltages to I supply to each three wires as I don't have a 3 phase supply. th-cam.com/users/results?search_query=lg+bldc+motor Thanks in advance for any follow up.
Hello Sam, Very nicely explained video. I would like to know more on detecting BEMF zero crossing scheme. I am trying but getting very complex waveforms. Can you please guide me?
Great video. Question. I'm replacing my ebike motor pcb. My original pcb has 5V GND SP H1 H2 and H3 components that's I'm familiar with and know how to connect. My replacement pcb has these connections PLUS a "K" (relay?) and "-" beside it. What is relay used for? Does K mean relay? And, since "K" is not a component on my original pcb does that mean this pcb will not work unless connected to some type relay? Tried looking online/Google. No luck. Need some help. Hope u can. /bklyn 👑
A 3 phase brushless motor has the following values. The maximum current drawn from the battery is 4.62 amps.. The thrust is 4025 grams with a three-bladed fan 18 * 8.. The speed at the maximum lifting force is 2780 rpm. The battery voltage is 23.46 volts. How much is the output power? How much is the efficiency?
Very Nice explanation Sir ! How to Derive Simulation in LT spice without actual BLDC motor part. Can i consider any known EMF value in Spice Simulation to derive the current and Voltage ?
@@pavamanp6873 If a motor is designed for a certain bus voltage level that is max AC voltage, then to get the specified RPM you need full AC voltage (M=1) which is approximately the back EMF (all approximate neglecting voltage drops and phase shifts)
☠️☠️☠️ I've been experiencing extremely dangerous episodes of the motor not stopping as soon as I turn the throttle , related to high humidity conditions ! I think it's because the humidity increases conductivity of the hall sensors in the throttle . can you recommend a good throttle ? I think the manufacturers are going to have to make them water proof. I experienced the same issue with a different throttle , battery and controller. just using the bike after a rain storm is enough to cause the issue. We must have a throttle will a switch to cut power ! ☠️ Also stop using hot glue on the Hall sensors ! It melts were I live ! And make the throttle not Fall apart so easy , and they need to be made with softer grips or made to accept normal grip's.
![ทททททททท #27 [หลุยส์ เค โตมายังไง ณ สระบุรี]](http://i.ytimg.com/vi/CaKoYw_Xmtg/mqdefault.jpg)
Great stuff, please more videos on BLDC
Will try😊
Only a person with a great understanding can make complex things explain as simple as possible! Nice video Prof.! One question, you've mentioned R, L components, why left out C, because in this case it can be neglected? every wire has the L, R, C components
Thanks for comment. The C component does not affect the basic operation (small enough) but can cause ringing problems and losses. Good point.
Dr. Sam : Great explanation. You made it very simple to understand.
Thanks Swaraj for the boost😊
Hi, I had a glimpse of a question by you about motor star connection? Somehow it disappeared. If relevant please post again. And BTW, if not a member of the group please join:
www.linkedin.com/groups/13606756
Best
How do I pick carrier frequency for the PWM signal used to control acceleration/brake regen? I have been building a custom driver and so far the motor spins the best at around 500hz, but not significantly better than at 350, 1200 and 16000 khz (PWM carrier frequencies). At 350hz carrier frequency the rotor speed, stator heat and unloaded power draw is the worst (probably too much short circuit load during the current recirculation period, as I think it goes in the equivalent of dis-continuous conduction mode). Changing the PWM signal duty cycle successfully alters the rotor speed and under about 30% PWM signal duty cycle the idle power consumption sharply drops. Advancing the hall sensor timing angle slightly helps with rotor speed and torque is reduced (as expected), but does nothing to help unloaded power draw.
For me thunderstruck moment was learning inverter stage as buck and boost converter. Its was really really helpful Sir. U r awesome for the humanity. Got some confusion in feild weakening about injecting out of phase Vin for short period...does that mean reducing the pwm pulses or average forward voltage?
👍
Thanks ! Very interesting and accessible indeed. Great job
Thanks
Amazing presentation, especially the regen braking section explaining the natural occurrence of a boost converter without dedicated components. A thing I have been wondering is why do basic brushed motors have one north-south pole pair per 360 electrical degress (2 magnets-1 north+1 south on the side, 3 coils on the rotor) vs brushless motors having double the magnetic pole count (12 magnetic poles-6 north south pairs on the rotor, 9 coils on the stator)? Is it related to the detection of the zero-crossing point or just a way to increase the motor torque within the same manufacturing complexity of the stator?
Thanks for input. Yes, Ilso think the reason is to smooth the torque
Please more videos about Calculation n How to design BLDC. . . .because your explanation is very usefull. . ..thank professor
Motor design is not really my "cup of tea"
Thanks for the presentation Professor!
In d-q axis, when rotor flux is aligned with d-axis, stator flux has to be aligned with q-axis(i_d= 0) for max torque per ampere. For field weakening, we orient "i" vector so that i_d < 0.
In abc-axis , this means that?
In order to achieve maximum torque per ampere, we need to align the EMF and current of the phase. When we want to achieve field weakening and increase the speed, we just decrease the current amplitude (to decrease the torque) and impose a phase-shift between to the current and EMF?
It is the way around. What matters is the actual physical 3 phase vecror space while the d-q is just a mathematical manipulation limited to balanced systems and no higher harmonics.
@@sambenyaakov Thanks a lot!
while PWM ing the on phase there are those large voltage spikes on that coil would adding capacitors between it and the grounded input help or just make things worse? ( I was thinking about capacitors that are non polarised between each phase s?
Also at what frequency does the 6 step operation work at? what about the phase PWM? (I know this one depends a lot on engine inductance but is there a x where if you go higher then it you should be fine?)
while the active PHASE is PWM ed are there moments when both the active phase and the ground phase are bot connected to GND or is the PWM ed active phase left to float?
A sinusoidal drive is the ultimate solution.
Thankyou for such a simple explanation for such a complicated control.It would be helpful if you could make a video with live implementation using a microcontroller 😊
Will try. Thanks for comment.
Nice presentation
Thanks
Thank you very much. It is very nice and helpful.
I need another video with PMSM
Thanks
Thanks for sharing Professor!
Thanks
@@sambenyaakov
I made this driver without a micrcontroller and it works pretty well th-cam.com/video/3iMqkmQMQTY/w-d-xo.html However, it requires a lot of manual adjustments to operate it. I would like to automate the adjustments without a microcontroller. I understand in principal how a closed loop works with a microcontroller, but I have no idea how to automate these adjustments without a MC. Where and how would I apply feedback with discrete components?
Do we actually need a back emf if we replace a bldc motor I mean does the back emf needs to be implemented if e make equivalant circuit, i try to test the motorcontrollers current and will measure if the commutation is going the right direction when controlling it, but does back emf have a lot of effect on tbis commutation?
I am afraid I don't follow the question.
I try to test the motorcontrollers DRV835x but I dont want to use the motor, i will replace the motor with his equivalant. So i will generate the
-Load(with my specific Resistor and Coil Value)(generate load stepwise)
-back emf with a variable trapezium voltage generator
-hall sensor simulation to simulate the hall sensors so actually the motorcontrollers thinks there is a turning motor but there is not.
- this is done due to functional testing of the motorcontroller currents and see the commutation are going to the right direction.
So my question is I want to understand better the presense of back emf in the application, do I really need to realise it. Thankyou very much.
Wow..thank you prof. It.s a full benifiecially lecture even ther.s some factors is uncovered but you.v put the dot on the note.
Sam Australia
Thanks
Prof. I.m studying a mechanic but highly interesting in Electromagnetic/motors and I really in need for a professional advice about an issue of the Flux...May I get your business email or if kindly drop me a line on
Seagull7@live.co.uk
And I.l get back to you.
Thanks in advance.
excellent😀
Thanks
Thank a lot Professor......great explanation
Thanks
In an induction motor the current change direction constantly and a supposed rotating magnetic field is producted that the rotor chases. In a bldc motor you have to change the polarity in the coils by various means and frequency to pull and to push preferably right? and of course one pair of coils to do nothing and so on. I sure also like to know the details about coil winding in terms of resistance and number of winding turns.
I seem to have a motor that appear to have lots of windings as such that it reads 100 ohm between each three legs (u,v,w) but most bldc motors are lik from 5-10 ohms..... This motor also have hall and pwm
You can drive a BLDC motor by a sinusoidal waveform, not much different from an induction machine.
@@sambenyaakov Thank you for your reply. . I am not sure what wires from my breaker box goes to the three wires in the above motor. With its resistance of the coils wires being high, I would think 240 V supply, having two wires and the motor with 3 wires, would I need to use a capacitor with certain uF specification? I don't have 3 phase supply at the house.
This is the motor but the spec on it with regard to voltage supply is for its control board which I don't think work any more.
On the motor hook up as you can see has the 3 wires for the motor and the hall 5 wires.
www.h-mac.com/amana-0131p00029S.html
Here is another motor I have. I am not sure if you have seen. These motors are in washing machines, the are typically a foot in diameter, with the magnet rotor being on the outside.. BLDC, three wires and hall sensor. The resistance between their 3 coil wires are 5 -6 ohms big difference with the above motor.
What voltages to I supply to each three wires as I don't have a 3 phase supply.
th-cam.com/users/results?search_query=lg+bldc+motor
Thanks in advance for any follow up.
Hello Sam, Very nicely explained video. I would like to know more on detecting BEMF zero crossing scheme. I am trying but getting very complex waveforms. Can you please guide me?
This involved. Many papers on that. If you have access, search IEEExplore
@@sambenyaakov Thank you. I will search.
Great video.
Question. I'm replacing my ebike motor pcb. My original pcb has 5V GND SP H1 H2 and H3 components that's I'm familiar with and know how to connect.
My replacement pcb has these connections PLUS a "K" (relay?) and "-" beside it.
What is relay used for? Does K mean relay? And, since "K" is not a component on my original pcb does that mean this pcb will not work unless connected to some type relay?
Tried looking online/Google. No luck. Need some help. Hope u can.
/bklyn 👑
Sorry, I am not familiar with this circuitry.
@@sambenyaakov no worries. thank you for responding. the pcb label K (in my case) is an additional/optional function for thermal sensor.
/bklyn 👑
Thank you!
👍
thank you!
🙏😊
Very cool, sensorless and weakening are always difficult to understand.
Thanks😊
A 3 phase brushless motor has the following values. The maximum current drawn from the battery is 4.62 amps.. The thrust is 4025 grams with a three-bladed fan 18 * 8.. The speed at the maximum lifting force is 2780 rpm. The battery voltage is 23.46 volts. How much is the output power? How much is the efficiency?
(torque*w)/V*I
Is it possible to control 20 BLDC drivers with variable speed as well as anti-reverse with two push-buttons
No sure I follow your question
Very Nice explanation Sir !
How to Derive Simulation in LT spice without actual BLDC motor part.
Can i consider any known EMF value in Spice Simulation to derive the current and Voltage ?
The EMF is the voltage expected at full RPM
Sir, Could also provide the EMF voltage range which we can consider for High Speed and Low Speed (High torque Condition) for Vin condition
@@pavamanp6873 If a motor is designed for a certain bus voltage level that is max AC voltage, then to get the specified RPM you need full AC voltage (M=1) which is approximately the back EMF (all approximate neglecting voltage drops and phase shifts)
Hi i m kapil from india 🤝so can u help me i min i want u send me all motors windings formula! So PLEASE...wait your reply
Amazing Video sir,
Can you please go deeper into the FOC control Algorithm in one of your future videos?
Thanks for note. Will try
☠️☠️☠️ I've been experiencing extremely dangerous episodes of the motor not stopping as soon as I turn the throttle , related to high humidity conditions ! I think it's because the humidity increases conductivity of the hall sensors in the throttle . can you recommend a good throttle ? I think the manufacturers are going to have to make them water proof. I experienced the same issue with a different throttle , battery and controller. just using the bike after a rain storm is enough to cause the issue. We must have a throttle will a switch to cut power ! ☠️ Also stop using hot glue on the Hall sensors ! It melts were I live ! And make the throttle not Fall apart so easy , and they need to be made with softer grips or made to accept normal grip's.
Thanks for sharing
Thanks
👍😊
best explanation!
Thanks
Can you help me in exchange for money, please?