Motor Control ICs Forum Discussions

[qwertyqwq35]

Hi all,

Since my last new pcbs arrived im struggiling to drive my motor smooth. And here what are my problems about running my motor.

First of all , the pcb design by me and im not using any official eval boards. There are two boards on my setup . The controller , which means imc101q048 and some other parts of drive , is included in small controller board. Other board has power stage , im393  and itrip circuit inside.  When these boards connected to each other , motor can spins (6k rpm) , but something unexpected weird situations happens.

1) When motor is spinning for a long time like 5-10mins , motor is suddenly stops to 0rpm(suddenly without lower its speed). After about 5-10secs, immidatly it spinning back without increase it speed. It spins like there was no stops.

Like that;  5000rpm spinning  >(after 5-10mins later)>   0 rpm stops immidiatly like rotor locked >(after 5-10 secs later)> 5000rpm again something like it didnt even stop before.

This situation looks very weird and i think it happens because of imc101q048 chip.

2) After 10-20mins of motor spin , imc101t048 chips starting acting weird and something like stuck or lock itself. Because when this situation happens motor is not spinning , imc101 to pc connection disconnects , imc101 doesnt respond any vsp commands and STATUS led blinking so fast than normal and it brightness getting lower like its power is nearly gone or voltage decrease on STATUS led pin imc101t. After this happens all i have to disconnect power to main and controller boards and wait at least 10-20 mins of time. After a long period of waiting , when power resupply to boards , it starts working normal and again after 20-30 mins later this thing happening again . So on.....

Those are my first problems to solve hopefully you can help me about it. Why those sittuations may happens ?

Thanks.

[Krupashankar]

Hi @qwertyqwq35,

Can you please share the motor datasheet, MCE Wizard ( .mc2)  and the latest schematics of the control/power board?

This will help us to understand the issue better.

Please make sure to follow the points mentioned in the previous thread. Gatekill & motor hardly moving 

Thanks,

Krupashankar

[qwertyqwq35]

Hi @Krupashankar ;

I have uploaded schematics of each pcbs , mc2 file and even with a video included that can be seen abnormal blinks on status led.

Yes, as you have said  , motor is same with my latest posts and again yes , i have changed mc2 parameters on my latest post as you have described. This is different then my previous pcb and with new ones , i managed to turn my motor about 9000 rpm succesfully.

But before beginning to search on my schematics i must say that , on main board pcb schematic, the R12 resistor (1kohms) remained open because for some reason  , that i have never understood yet ,  lm393 comparator gives fault gatekill error and  like 500mv on noninverting pin of lm393 even there was no AC power applied to the board(anode voltage of D1,D2,D3 is equal to zero volt ).  I think this problem cause of lm393 itself i dont know. So for that reason i have desoldered R12 resistor to get rid of faulty ITRIP effect. After that , as i have said before i turned motor rapidly and played some times.

Today i have tested my setup with fresh new imc101t chip and fresh pcb . But after a while , it started to act just like previous imc101t and started to blink status led wierd.  But before this happen, i managed to spin my motor shaft around 9k RPMs .

By the way you can find motor manual in here my previous post : https://community.infineon.com/t5/Motor-Control-ICs/Gatekill-amp-motor-hardly-moving/m-p/394943

Hopefully you understand well my situations.

Thanks.

[Krupashankar]

Hi @qwertyqwq35,

Based on the MCE Wizard file shared, We can see that over temperature fault is enabled when NTC falls below 2.14V.

From the schematics Rext is 5 Kohm and Thermistor resistance at 65 degree Celsius is 9.303 K-Ohm This will generate voltage less than 2.14V if the temperature is above 65 degree Celsius.

This results in over temperature fault and motor stops.

Can you please  observe the fault displayed in MCE designer when the motor stops.

For more details please refer to the section 8 Thermistor Characteristics - CIPOS™ Tiny IPM 600V/20A

Thanks,

Krupashankar

[qwertyqwq35]

Hi @Krupashankar ;

Those resistor values are selected based on EVAL-M1-101T and  EVAL-M1-CTF620N3 boards which published by infineon. I will try to change parameter to 1.62v for ntc trip and see what is going on. I actually didnt  realized that situation because i just set that parameter on EVAL-M1-CTF620N3 manual at Figure - 21 .  I must miss explenation above that figure. :))

When motor stops , mcedesigner nothing says about it. It is still says " Motor Run" condition and with green light.

So have ever check my unexpected blinking status led ? May that is happenin because of over temperature trip ?

 

[qwertyqwq35]

Hi @Krupashankar 

I have just reprogram imc101t NTC temperature parameter. I have reduced previous value to 1.63v. After a while spines motor shaft without any problem about 8600rpm , suddenly it stoped when there was no error output on mce designer , it was still on "motor run" situation. After i had pull down to 0Volt to VSP voltage. And again i reapplied some VSP on it and there mce designer said "gatekill" error and status led just started to blink weird again. But this time it was giving gatekill error and that was the first time then my previous attempts. 

I think we will find solution about this situation. I'll be grateful for more help. 

Thanks 

[Krupashankar]

Hi @qwertyqwq35,

• Can you please confirm the motor max speed, Motor Max current?
• We could see Gatekill current is configured at 14.5 A but motor max current is 5.5 A from the datasheet. For safer operation Gatekill current should be configured as motor maximum current.
• From the datasheet motor rated RPM is 4300 but the motor is being operated at 8600RPM.
• 
• Can you please measure what is the actual motor phase current at 8000 RPM?
• Please ensure LM393 functionality,  if ITRIP section is not used please select only the comparator as the Gatekill input source in Ques-91 Gate Kill Input Source.

Thanks,

Krupashankar

[qwertyqwq35]

hi @Krupashankar 

I attached mcedesigner Iu,Motor speed oscilloscope screen.

I have reached that value by using Field Weakenen drive method as you can see on my mc2 file. But without this drive method, i succeded to drive shaft around 5000rpm as mce designer scope says. I dont know how can it possible but its true.

On scope , current measurement seems like triangle waveform for somehow reason.

Ok i will select as gatekill only source.

If you need anything let me know.

[Krupashankar]

Hi @qwertyqwq35,

1) Gatekill fault arises if the current is above 15A (configuration in the MCE Wizard Ques 93) or due to ITRIP.

As we could see from the above image the motor is being operated at a higher current and speed than the rated values for a prolonged duration which will cause damage to the motor.

Can you please capture the current during gatekill fault by using the below settings in MCE Designer:

This will help us to understand the issue better.

2) Is the current waveform triangular during nominal operation ( Speed less than 4300)?

Thanks,

Krupashankar

[qwertyqwq35]

Hi @Krupashankar ;

I have just do some test right now. Sorry for been late, i was at the bussiness trips since 2-3days.

I'll share the data i have got today;

1) Again i have spinned rotor at maximum speed about 15 mins then again unexpected rotor stops began. Began time is about 1-2 mins and after that time , rotor spins again with its maximum speed just like nothing happened. While this unexpected stop time , status led was lighting and there was no error on it and also on mcedesignner. After that time , it spined back 2-3mins more but after it totally stopped. Now status led began to blink just like before. I have added that video below .zip file. You can see anomaly blinking situation of the led.

2) I have added a screenshot when there was no VSP voltage and so rotor doesnt move at all. Maybe that waveform helps you about those unexpected stops.

3) I have added a video and a waveform screenshot of when rotor speed lower than 4000rpm. As you can see , the current waveforms are triangle or something like that. Since i have prototyped a few board, i have never see a clear sinewave. Why may this can be ?

4) I have noticed that, when Status Led starts to began weird blinking ( as i have said on "1") , switching power to off and back on again , doesnt help to get rid of this weird blinking situation. But when i remove controller board to main board, controller board began to work expected.Now it can communicate with my pc , mcedesigner status gets ok and status led get back to work with normal blinking frequency/brighness( because of error situation for gatekill&low dc voltage) . I think this means that , problematic side is main board on my setup. What do you think?

5)I couldnt capture Trigger Fault waveform for some reason can you guide me more about how to use it ?

Thanks.

[Krupashankar]

Hi @qwertyqwq35,

Please follow the below methods to identify the cause of motor stop:

• Can you please increase the sampling rate to observe the current waveform at 2500RPM.
• 
• Note: If the sampling rate is very less the current waveform may not be sinusoidal
•  Please disable VSP mode and operate the motor using MCE Designer. Using below setting. Modify Target speed to operate motor at 2500 RPM
• 
• Note: In VSP mode MCE restarts 3 times in 10 Sec intervals configured in MCE Wizard. As the fault will get cleared automatically in VSP mode to identify the fault we request you to operate using MCE designer.
• Status LED will blink if there is any fault. This is displayed over MCE Designer Window at the bottom left.

Thanks,

Krupashankar

[qwertyqwq35]

Hi @Krupashankar ;

+I have managed to spin motor with uart communication. Now it seems that motor started to work properly , since about  3 days , i havent got any problem to spinning motor using UART. It never stopped again when it is alreaddy spinning , rpm is now clear and smooth at more than 500rpm. Now it seems , this is ready for fan application using uart. But why imc101 acting abnormal at vsp mode ? I wanted to control motor using a potantiometer by changing vsp voltage 0-3.3v adjusting knob.

Here i have added screenshots at target speed is 2500rpm. But in real speed at this point is not 2500rpm, it is just around 2100rpm. You can see this value on mcedesigner osclilloscope. Why ?

+Also you can see at maximum sample rate , current wave is still triangle , i didnt manage to see any sine wave with different speed rates.

+Since i have changed trigger mode to fault activate,  oscilloscope didnt operate. I m not clear with that but it seems to be , it works when fault accures on imc101t. So no problem at all.

+Also after changing control mode VSP to UART , abnormal led blinking status gone. Now it works properly.

+ At lower than 500rpm motor not spinning , how to get rid of this situation ? Also at this low speeds, how toincrease torq of motor ?

[Krupashankar]

Hi @qwertyqwq35,

1) Can you please check if the VSP voltage is stable( As UART control is working with the same setup) and can you please try giving a fixed voltage? As per the maximum RPM configured at 12000 and VSP at 24% as a starting threshold, the minimum speed achievable is 2880. We would recommend operating the motor at rated speed and tune for its performance,  field weakening can be implemented once the motor is stabilized for rated operation.

Can you please try using the below setting in the MCE wizard:

2) Please try adjusting the flux estimator time constant and enter accurate motor parameters for accurate speed measurement.

3) Sorry for the confusion please try the following settings to capture the current waveform.

Can you please try the above settings and share the results with us?

Thanks,

Krupashankar

[qwertyqwq35]

 Hi,

Current waveforms is now worse then before.

I havent tried VSP mode yet.

 

[Krupashankar]

Hi @qwertyqwq35,

As we could see the current waveform is not sinusoidal.

There can be multiple reasons:

• Please make sure the motor parameters are accurate. 
• Improper current sensing

As we could see from the datasheet the motor Inductance ( Ld,Lq) parameters are line-to-line values.

but the MCE wizard needs per-phase values. Enter half the value of line-to-line measurement (per phase = 0.5*line to line) 

• From the above datasheet Inductance is line to line value so it needs to be half for per phase inductance
• In the same way can you please confirm if the Winding resistance entered in the datasheet is per phase resistance.

Can you please change the above parameters and capture the current waveform?

Thanks,

Krupashankar

[qwertyqwq35]

Hi @Krupashankar 

I have updated parameter files. And here i share oscilloscope screens and mc2 file here;

Note: Winding resistans was not clear. So i measured using a multimeter line to line resistance and it was around 27-28ohms. So i have updated per phase resistans value by 23.7(from datasheet) devided by 1.732(sqrt(3)).

As you can see from screen.png files, current waveform still anormal. I started to think , it needs redesign of pcb. Shorter paths etc.

From your old posts, i have checked vsp voltage and it is pure 3.3v from a high quality linear regulator which is also voltage supply to imc101t. When i apply full voltage (3.3v) to VSP pin, RPM is limited to 2600rpm. Why is not 4300rpm. Although i could spin 4300rpm with UART mode. Why? By the way i have checked that DIR pin is working correctly when VSP mode is active.

Thanks.