Current Protection issue in BLDC motor

[c_mitra]

Hello,

By hand I am not making it standstill. I am just applying load by hand.

The first situation is,
Suppose, motor is at full load and POT (Throttle) is at maximum and then motor is trying to start and somebody picks rotor by hand then motor is stopping. It should reach 20 A and then it should stop as 20A set as current protection range. But it is stopping at 1 A or 2 A of current.

The second situation is if motor is at full load i.e. at 19A (as 20A is shut down of motor). Then I stopped the supply. Then I again starts the supply, at that instance the motor is running and reaching to 19A.

The third situation is, if motor is running at 19A i.e full load and I stopped the supply and increased some more load using dynamo meter (lets say 25A) and then I started the supply at that time also it is running and once reach 20A it stopps.

The fourth situation is, if motor is running at 19A i.e full load and I stopped the supply and increased some more load using dynamo meter (lets say 30A) and then I started the supply at that time motor is stopping at 7-10A. But actually motor should stop at 20A.

What is the significance of I stopped the supply? Exactly what you do and why?

Put a small cap in parallel with R20.

 

[RenesasT]

Hello C_mitra,

Here the meaning of I stopped the supply means SHut down the suppy.

I had done the same with 0.1uF,1uF,4.7uF,47uF,100uF capacitors, but the issue is same.

 

[Easyrider83]

How do you open the gates of Q1,Q2 and Q3? I don't understand how this schematic should work. Seems to be those mosfet switched on as current limiting sources. Not as power switches. They should warmup quite fast and probably should blow!

 

[RenesasT]

Hello Easyrider,

The gate of MOSFETS are controlled by a resistor divider. The ULN2003 IC is used between MOSFets and controller.

As the ULN2003 requires sinking current less than 0.25 mA. So I have adjusted the current below 0.25A. The Mosfets are not blasting. I am using this from last 3 months.

Q1,Q2,Q3 controlled by U1, U2 and U3 o/p's of controller (shown in the schematic) . ULN2003 is negative/reverse buffer IC.

When U1 is high A becomes low. When U1 becomes low, A becomes high. This is happening with U2 and C,U3 and E. (last page of schematic)

Hence the controlling of MOSFETS is happening.

 

[Easyrider83]

Your upper mosfets will never be opened fully belive me or not. As far as I remember I said the same last time when you posted this schematic before.

 

[RenesasT]

Hello Easyrider,

I am trusting you . I am not saying you are wrong. But its working since a long.

What I am doing from controller side is, I am using upper MOSFETS as port pins and lower MOSfets as PWM pulses.

Still if you are feeling that the upper MOSFETS will not get open fully, Please let me know what can be done in the same.

 

[Easyrider83]

It is not my feeling, it's just pure phisics. Read more about 3 phase fet drivers.

 

[RenesasT]

Hello Easyrider83,

What changes required if the voltage is 12V,24V,36V,48 and 60V instead of 330V DC.

 

[c_mitra]

...changes required if the voltage is 12V,24V,36V,48 and 60V instead of 330V DC.

That can be changed depending on the motor voltage; but your problem is elsewhere.

Do not leave the SD pin hanging; tie them together. All the Vdd pins do not need a 100uF cap; one is perhaps sufficient. But you can use a 0.1uF ceramic close the Vdd pin to provide rush current.

But check the software if reset and restart are fine; when you stopped the supply, did you shut down the microprocessor too?

Clearly the problem is elsewhere.

 

[Easyrider83]

First you choose fet driver, than you read manual and get all what you need. No point to support this topic anymore.

 

[RenesasT]

Hello C_mitra,

It means micro controller is also shutting down. I am also thinking the problem is somewhere else.

Hello Easyrider,

You are right. The driver on which I am working is running since last 3 months. I know, it may have problem but current problem is might be due to the different thing. It does not mean, you are wrong. For next project, I will select the driver using IR2113 same like you have suggested. I have completed 80% of my project based on the driver which I posted the pdf. 20% part is only pending due to this issue.

 

[KlausST]

Hi,

All the Vdd pins do not need a 100uF cap; one is perhaps sufficient. But you can use a 0.1uF ceramic close the Vdd pin to provide rush current.

True, if you speak about IDD only. But this node needs supply the current pulses for the bootstrap circuit, too.

Klaus

 

[RenesasT]

Hello All,

What to do in existing driver?
Any more information is required from my end. Please let me know.

 

[RenesasT]

Hello all,

I have also implemented the circuit given by easyrider.

In that problem is with start. I have to start moter by hand.

It is not starting if POT is varied. It's required little push and then it is running properly.

Please help me.

 

[c_mitra]

What is the power supply voltage you are using (for the motor)/ are you using another supply for the 12V for the controller? How the microprocessor is getting the supply? What is the rated power/voltage/current for the motor?

Motor fails to self-start is very likely a current supply problem (my guess); when you start it by hand, does it develop full torque (if yes, the driver is fine; if no you need to dig more)?

 

[KlausST]

Hi,

Hello KlauST,

Please suggest your views.

My view:
Since the beginning it is the same:
We ask for informations, but you don't give them.
No code, no scope picture, no useful schematic, no debug information...

As said before: It is very annoying to ask repeatedly for the same informations.

Klaus

 

[RenesasT]

Hello C_mitra,

Thanks a lot for your reply. Please be with me.

I have only single supply. I am giving 24V to the mosfets. I am using 7815 to give supply to the IR2113 (high low driver). Also I am using 7805 to give supply to the 7805.

Currently motor is with no load.

Motor is failing to self start.I guess it is related to charge pump. If POT is full and I am giving hand start then it is starting properly and also giving full torque.

Please let me know, How I can reduce this issue. The circuit is same as easyrider.

Please find the circuit diagram attached with this mail. Only change is that, the capacitor between Vb and Vs is 1uF/50V and the MOSFET is IR3205.

Please help me.

- - - Updated - - -

Hello KlausST,

Since the beginning it is the same:
We ask for informations, but you don't give them.

Please do not say like this. I need you and I need your help always. Please let me know what information you need. I have attached the schematic.

Please be with me.

 

[KlausST]

Hi,

My really last attempt. Because you seem to read only a tiny part of our posts.
I wonder how you can read this sentence:
"We ask for informations, but you don't give them."
but don´t seem to read this next sentence:
"No code, no scope picture, no useful schematic, no debug information..."
because you ask...
"Please let me know what information you need"

I will come back only if the above informations are complete.

The schematic is not complete. But it´s a new one we´ve never seen before...and - to be honest - I doubt that this equals your circuit.
Issues in the schematic: R7, controller, OPAMP values are missing
* C4, C6, C7, C8 make no sense.
* Power supply bulk capacitors and fast ceramics capacitors are missing.
* Did you read IR2113 related "Design tips"? There is a good reason why the manufacturer gives such informations.
There you will find:
d. Bootstrap Diode
The diode must have a BV > DC+ and a fast recovery time
(trr < 100 ns) to minimize the amount of charge fed back from
the bootstrap capacitor to VCC supply.
--> A 1N4007 diode is not suitable.

We have no idea to what input of the microcontroller the signal "CURRENT_PROTECTION" goes. Is it a standard logic input? Is it a comparator input - with what threshold level? Is it an ADC input with what sample rate and how the signal is processed.

We don´t have a crystal ball.

I recommend you to read the whole thread from the beginning and give item by item every detail
* we asked for ..
* or we mentioned that the information is missing.

Klaus

 

[RenesasT]

Hello Klaus,

Sorry for your inconvenience. Please help me with the solution. I am giving you all the details as below:

1) The circuit is given Easyrider. Some parameters from the circuit has changed. If that could be the issue, I am ready to add them. Please let me know the same.

2) I have removed C6,C7,C8.

3) Please do not consider other part apart from controller and driver. Please forget about OP-amp. I will first only run the motor and then will add protections.

4) I have taken hall sequence at micorcontroller port P6.0,P6.1,P6.2. All halls are pulled up.

5) I just wanted to run the motor and then I will add the protections. I don't know how to send code here. apologies for the same. I have done the code in a such a way that it will only take signals from hall and will fire the MOSFETS. The motor is running properly but self start is not there. I think the issue is with charge pump. More about code, I have used 3 port pins and 3 PWM signals from controller. All bottom MOSFETS are fired by PWM and upper MOSFETS are fired by ports. Here port means high or low i.e logic 1 or logic 0.

6) I have changed 1N4007 to EGP10G. I can also use FR107 if you recommend to use.

7) The circuit I posted has some changes. The capacitor between Vb and Vs is 1uF/50V and the MOSFET is IR3205. Requesting you to consider only driver section. The Vcc of IR2113 is 15V and the Vdd to IR2113 is 5V. The supply the controller is 5V.

8) For oscilloscope view, please finalize which pin readings you require. I will take according to your choice and will post here.

Please do not say like you will not help me. I need your help forever and forever. If something is missing, I am apologizing you in advance.

Klaus, please reply me. I would like if you are with me always.

 

[RenesasT]

Hello All,

As per the advised of Easyrider, My old circuit has some issues. So I am testing new schematic provided by Easyrider. Currently I am just trying to rotate the motor and I am not considering any protection. Please advice your views. Also let me know, what changes would required if I am increasing dc line voltages, 12V,24V,36V,48V,60V,230V.

Awaiting for your reply.