DC Motor Controller

Thread Starter

City106

Joined May 30, 2017
3
Hi Electronics Professionals
I have a problem with my home made Golf Cart
Data:
System voltage=48 volts DC
Driven motor 48 v 2600 watts Brushed Motor
System Load on start spikes to almost 120 A
System load after start on slow =60A
System Load on fast and load = 70 to 80 A
History.
A speed controller based on IGBT burns out in 20 hours of running
there is no sign of over heating on the body of the IGBT
Controller config
Pwm driver driving the IGBT
IGBT
Free Wheel Diode
Capacitor for reducing ripple effects
So it did not work

Now I am working on plan B
using 8 mosfets to fire in a sequence with the common buss for the gate and drain to load
using octocoupler to drive the mosfets at 15 v
using ardunio to drive the otocouplers in a sequence without pwn as on off system
the controlled delay will be used to control the output of the mosfet
delay change to 10 milliseconds for low speed and increase in delay for more on time till as long as the mosfets remain cold
the IRF 4110 data sheet is attached
On the gate and source end there will be an additional free wheel diode
Please Advise
Regardsmili.jpg


Please advise
 

Attachments

TeeKay6

Joined Apr 20, 2019
532
Hi Electronics Professionals
I have a problem with my home made Golf Cart
Data:
System voltage=48 volts DC
Driven motor 48 v 2600 watts Brushed Motor
System Load on start spikes to almost 120 A
System load after start on slow =60A
System Load on fast and load = 70 to 80 A
History.
A speed controller based on IGBT burns out in 20 hours of running
there is no sign of over heating on the body of the IGBT
Controller config
Pwm driver driving the IGBT
IGBT
Free Wheel Diode
Capacitor for reducing ripple effects
So it did not work

Now I am working on plan B
using 8 mosfets to fire in a sequence with the common buss for the gate and drain to load
using octocoupler to drive the mosfets at 15 v
using ardunio to drive the otocouplers in a sequence without pwn as on off system
the controlled delay will be used to control the output of the mosfet
delay change to 10 milliseconds for low speed and increase in delay for more on time till as long as the mosfets remain cold
the IRF 4110 data sheet is attached
On the gate and source end there will be an additional free wheel diode
Please Advise
RegardsView attachment 193937


Please advise
Please post the schematic of your existing design for review. Perhaps we can identify a problem that can be fixed. By the way, your cart does not provide a "reverse" drive?

In the sketch for your proposed octal drive...I hope you are aware that the motor should not be connected between the sources and drains of the MOSFETs (or IGBTs). The sources should be grounded and the motor placed between the drains and the main positive DC power source. An octal drive seems a very complicated solution when almost certainly much simpler solutions are available. You have already stated that the IGBT is not getting hot, so the problem is probably not related to device dissipation, and thus using 8 devices is unlikely to improve the situation.
 

Thread Starter

City106

Joined May 30, 2017
3
Please post the schematic of your existing design for review. Perhaps we can identify a problem that can be fixed. By the way, your cart does not provide a "reverse" drive?

In the sketch for your proposed octal drive...I hope you are aware that the motor should not be connected between the sources and drains of the MOSFETs (or IGBTs). The sources should be grounded and the motor placed between the drains and the main positive DC power source. An octal drive seems a very complicated solution when almost certainly much simpler solutions are available. You have already stated that the IGBT is not getting hot, so the problem is probably not related to device dissipation, and thus using 8 devices is unlikely to improve the situation.
An octal drive seems a very complicated solution when almost certainly much simpler solutions are available.
The land I live in solutions are rare and getting a 2 pound product can cost upto $50 for shipping alone , the advance drivers
cost a lot , almost 750 to 1000 U S D ,So I am left with only one option MAKE it I bought a driver module based on a CM100DU
The specifications of this brick type is more than what I need .
cart does not provide a "reverse" drive?
there is no reversing system in this module , it is arranged with a toggle switch where by six relays make shift and the motor starts turning back. and mostly the system burns out on reverse drive even if done after complete stop
you will see how i am makinig an effort for resolving an issue which might not be as complicated as I experience ,
but there are many factors . using mosfets was in sequence the major uestion was how hot will the mosfet get once its on time is
10 milliseconds.
 

Attachments

TeeKay6

Joined Apr 20, 2019
532
An octal drive seems a very complicated solution when almost certainly much simpler solutions are available.
The land I live in solutions are rare and getting a 2 pound product can cost upto $50 for shipping alone , the advance drivers
cost a lot , almost 750 to 1000 U S D ,So I am left with only one option MAKE it I bought a driver module based on a CM100DU
The specifications of this brick type is more than what I need .
cart does not provide a "reverse" drive?
there is no reversing system in this module , it is arranged with a toggle switch where by six relays make shift and the motor starts turning back. and mostly the system burns out on reverse drive even if done after complete stop
you will see how i am makinig an effort for resolving an issue which might not be as complicated as I experience ,
but there are many factors . using mosfets was in sequence the major uestion was how hot will the mosfet get once its on time is
10 milliseconds.
@City106
I have listened to your video several times but I am still unable to understand much of what you say. The problem is not with your language; the problem is both with my not-good hearing (almost deaf in one ear) and, I think, with the space in which you are speaking and recording. That space give a slight resonance to the recording that makes it difficult for my ear to understand you. Nevertheless, I will make some comments and ask more questions.
1. In your first post you say the motor is rated for 48V and 2600watts. Yet in your video you speak only of 24V, not 48V. ???
2. Pls give part/model numbers for the circuit/module that you want to use as a gate driver. If I can find a data sheet for that module, I can better understand what you are asking.
3. I understand that the module to the left in the video is an Arduino Nano. I understand that the module to the right is a buck converter. I cannot understand you when you describe the module in the middle space of the video. However, I believe (viewing the partslist you gave in post#1) that module to be a PWM driver, including an IGBT, flyback (freewheeling) diode, and PWM circuitry. It is clear that you have smooth control of the motor drive level/speed. So, more questions and comments:
*1. What kind of signal couples your Arduino to the PWM module? Does the Arduino create a PWM signal or is the PWM signal created by the PWM module?
*2. What voltage (24V?) powers the PWM module? Is that the voltage you will use in your final--or next--design? Is it true that the PWM module includes a MOSFET (per the datasheet you posted) or does it use an IGBT? Is it true that you wish to use an IGBT? Why? What is the frequency of the PWM?
*3. What are the input and output voltages of the buck converter? Do you intend to use that buck converter in your next design? What is the output current rating of the buck converter? What provides the input power for the buck converter?
*4. I cannot say whether your current PWM module is suitable as a driver for an IGBT unless I can find a schematic for the module.
*5. Can you put a fuse in series with your motor to try to prevent MOSFET failure? (So that--perhaps--each failure may not destroy the MOSFET.) What kind (part number or specs) of flyback protection do you have connected across the motor (or across the MOSFET)?
*6. After you have had a failure, how long did you wait before checking the MOSFET for heating? If there was not significant heating after running for several minutes, then I think the MOSFET power dissipation is not what causes failure (unless something caused an instantaneous very high power condition). It is more likely that (a) there is some failure of the PWM drive signal to the MOSFET gate or (b) a high voltage transient that raises the drain-to-source voltage above the device rating or (c) a problem with the routing of ground and power supply wires. Understanding the stress on the MOSFET can get complicated as that device very likely has a "safe operating area" (SOA) rating that is less than the simple Vds(max) and Id(max) values indicate. A high current motor with brushes is likely to create considerable electrical noise as the brushes constantly make and break contact with the commutator. That noise can cause problems for the PWM module and (because that noise can be very high frequency, even RF) even for the Nano and buck converter.
*7. Besides the multimeter(DMM/VOM) that you show in the video, what other test equipment do you have access to? An oscilloscope?
*8. I still recommend against the octal design. The best solution to a problem is not to create new problems. Instead, understand why the current design does not work.
 

Thread Starter

City106

Joined May 30, 2017
3
Sorry for un complete information.
I think this short clip will explain most of it in a decent presentation which will be understandable

L293d is H-Bridge what you see in the middle between ardunio and buck converter is digested and assembled model of this IC
ready to use , My question is [ can in use the output of H bridge as a IGBT driver.
The output voltage has a frequency Or square wave
the voltage is variable and is controllable with an external device like a pot
in this example he is using a 9 v batt but I am using a 12 v source.
If you have a design that can solve this issue I would rather follow instaed of going a long way of experiments
Regards
City
 

Attachments

TeeKay6

Joined Apr 20, 2019
532
Sorry for un complete information.
I think this short clip will explain most of it in a decent presentation which will be understandable

L293d is H-Bridge what you see in the middle between ardunio and buck converter is digested and assembled model of this IC
ready to use , My question is [ can in use the output of H bridge as a IGBT driver.
The output voltage has a frequency Or square wave
the voltage is variable and is controllable with an external device like a pot
in this example he is using a 9 v batt but I am using a 12 v source.
If you have a design that can solve this issue I would rather follow instaed of going a long way of experiments
Regards
City
1. You did not answer most of my questions.
2. The L293d and L298 are different devices; be clear about which you are trying to use. The L293d package is an ordinary DIP. The L298 package is a double-row SIP with a large, extended heat sink plate. Both generally require heat-sinking, although of different styles.
3. MOSFETs and IGBTs are different kinds of devices; be clear about which you are trying to use.
 
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