• Vishnupriya murugesan

Speed Control of BLDC Motor using Sliding Mode Control






Speed Control of BLDC Motor using Sliding Mode Control


Hi viewers welcome to LMS solution!


Today we are going to see about speed control of bldc motor using sliding mode controller so this is a simulation model we developed for speed control of bldc motor using sliding mode controller this simulink model consists of a dc source and then three phase voltage source inverter and then bldc motor drive and then here we have motor parameter that mean measurement of motor parameter like hall sensor output speed of the bldc motor and then electromagnetic torque so this is the sliding mode controller the sliding mode controller received two inputs so one is reference speed another one is actual speed so after comparison of reference speed with actual speed we have error speed and then rate of a change of error so that going be process via sliding mode control like x1 and x2 x1 and x2 so inside this function we written that the sliding mode surface so this is a surface of the sliding mode controller so s which is equal to x2 plus 200 into absolute value of x1 power 2 multiplied with the sign of x1 so this is a sliding surface for that sliding mode controller so this slide mode controller generate the modulated signal or else we can call this duty cycle so that duty cycle going to be process via switching logic circuit of bldc motor so that modulating signal or duty cycle going to be compared with the the triangular wave so it will be generate the PWM pulse so that PWM pulse is going to be ANDed with the hall sensor output from the bldc motor so each AND GATE output going be used for drive the voltage source inverter okay so here we are having the six pulse so this six pulse going to be drive the voltage source inverter to control the speed of the bldc motor so here you can see that gate pulse is given to these voltage source inverter go inside so you have six switches right so these six switches will be drive from that switching logic circuit to control the voltage of the bldc motor in order to control the speed of the bldc motor.


Here we provide the reference speed so initially we provide the reference voltage is 1000 rpm after 0.2 second the reference speed change to 1500 rpm and here we are providing the torque input for bldc motor so here we are providing that torque input for Bldc motor is 5 Nm so i am going to simulate this model and then i am going to check the result of the speed so here you can see that so this is a variation of the speed so initial speed we are fixed at 1000 rpm so here you can see that the speed of the bldc motor is maintained at 1000 rpm after 0.2 seconds we are changing the reference speed to 1500 rpm so because of changing reference speed you can see that the actual speed of the motor change from 1000 to 1500 rpm without any overshoot so i'm going to zoom this little bit so here you can see that so initially we are having the overshoot around 20 rpm okay and then i'm going to zoom this portion and here when we are operating the machine at a 1500 rpm so we are getting the overshoot around 6 rpm okay that means 20 that means 20 divided by 1000 so it's around two percentage right two percentage of overshoot and six divided by thousand five hundred so that means point four percentage overshoot so we are getting two percentage overshoot when we are operating the machine at the 1000 rpm we are getting 0.4 percentage overshoot when we are operating the machine at 1500 rpm next i am going to operate the machine that means initially i am going to make reference speed equal to 1500 rpm and then i'm going to make the final speed of the machine that means after 0.2 second i'm going to make the speed of the machine equal to 200 rpm and then i'm going to check the result so now you can see that initially the speed of the machine reached 1500 rpm okay after 0.2 seconds the speed of the machine and the reference speed going to change from 1500 rpm to 200 rpm so because of that the machine is comes to 200 rpm here we can see the detail that means that machine speed is maintained at the 202 rpm that means having error around 2 rpm okay and then here you can see that the machine almost maintained 1500 rpm with overshoot of 0.4 percentage so far step change that mean step increasing speed reference as well as step decreasing speed reference the sliding mode control effectively control the bldc motor speed okay and also here you can see that this is the torque of the machine during change of speed reference command okay because you can see that it always maintain five newton meter during the disturbance that we during that reference speed command the torque of the machine can be changed okay in order to balance the power right after that some point it comes to five newton meter okay so this is a working of a speed controller bldc motor using sliding mode controller thanks for watching our videos kindly subscribe our channel and also click bell icon for notification about upcoming videos thank you thank you so much bye

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