Hi,
I am currently working on a project using a 3 phase BLDC hub motor. I am attempting to create a motor controller for this bicycle hub motor and have gone through a few different design iterations.
The motor is a 48V 20A ~ 1000W. I have 6 PWM signals that have been created from a dsPIC33fj microcontroller. These PWM signals are level translated to 12V logic and run off a frequency of 16kHZ.
From my earlier designs I attempted to feed these directly into a 6 FET 3 phase H-bridge, but learned that I would need an IC gate driver to properly switch them on. I am using an IR2110 gate driver for each phase of the h bridge. I am also using STP40NF20 transistors for the h bridge
Now for my issues. I have successfully gotten the BLDC motor to spin from a 48V current limited supply using a variable resistor that changes the duty ratio of my PWM signals. The main problem is that at higher duty ratios (higher wheel speed) the motor begins to make strange noises. My first thought is that there is not significant dead time for the FETs turning on or off. I am using a 1.2us dead time between state switching to no avail.
I have also discovered that using a lower gate resistance for each FET (currently have 100 ohms) burns which ever ir2110 module is connected to Phase A.
My schematics for the system are attached to this post
Any help would be greatly appreciated.
I am currently working on a project using a 3 phase BLDC hub motor. I am attempting to create a motor controller for this bicycle hub motor and have gone through a few different design iterations.
The motor is a 48V 20A ~ 1000W. I have 6 PWM signals that have been created from a dsPIC33fj microcontroller. These PWM signals are level translated to 12V logic and run off a frequency of 16kHZ.
From my earlier designs I attempted to feed these directly into a 6 FET 3 phase H-bridge, but learned that I would need an IC gate driver to properly switch them on. I am using an IR2110 gate driver for each phase of the h bridge. I am also using STP40NF20 transistors for the h bridge
Now for my issues. I have successfully gotten the BLDC motor to spin from a 48V current limited supply using a variable resistor that changes the duty ratio of my PWM signals. The main problem is that at higher duty ratios (higher wheel speed) the motor begins to make strange noises. My first thought is that there is not significant dead time for the FETs turning on or off. I am using a 1.2us dead time between state switching to no avail.
I have also discovered that using a lower gate resistance for each FET (currently have 100 ohms) burns which ever ir2110 module is connected to Phase A.
My schematics for the system are attached to this post
Any help would be greatly appreciated.
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