BLDCmotorDriver

Introduction

This library is still being developed.

This is a Wiki page about BLDCmotorDriver library developed by TVZ Mechatronics Team. The library is part of our project of creating an e-bike which is supposed to drive/run a 3-phase brushless DC motor with Hall sensors.

We are testing our library on NXP mbed LPC1768 platform and driver DRV8301 from Texas Instruments to run our testing BLDC motor. Next step of our project is creating a standalone library for DRV8301.

Hall sensors

In our BLDC motors there are three Hall sensors located 120 degrees from one another, they are identified as InterruptIn/DigitalIn on mbed and they send zeros and ones on TeraTerm with we locate in which sector

Na našim testnim BLDC motorima postoje 3 halova senzora, koji su udaljeni za 120 stupnjeva jedan od drugoga te inicijaliziranjem svakog pojedinog kao InterruptIn/DigitalIn na pinovima mbeda preko terminala na računalu (TeraTerm) dobivamo prikaz binarnih nula i jedinica koji se slažu sa trobitnim gray-evim kodom, s time da smo kombinacije 000 i 111 definirali kao fault vrijednosti. Pošto se slučajevi kada su sva tri hallova senzora upaljena ili ugašena ne mogu dogoditi tj. ne bi se smijeli dogoditi, ukoliko je došlo do takve situacije dogodio se kvar na hallovim senzorima te bi motor trebao prijeći u mod rada bez hallovih senzora.

With that we got six combinations, which we use to determine six sectors:

001 - Sector 1
011 - Sector 2
010 - Sector 3
110 - Sector 4
100 - Sector 5
101 - Sector 6

Nakon toga odredili smo za sve tri faze stanja mosfeta..

/media/uploads/dfraj/3-bit_gray_code_ring.jpg

Components

mbed NXP LPC1768 https://developer.mbed.org/platforms/mbed-LPC1768/
DRV8301 http://www.ti.com/product/drv8301
CSD18533Q5A 60V N-Channel NexFET Power MOSFET http://www.ti.com/product/csd18533q5a
3-phase brushless DC motor with Hall sensors - BG 65x50 dunkermotoren http://www.dunkermotoren.com/default.asp?id=10&mid=28&lang=2
3-phase brushless DC motor with Hall sensors - nine continent 2807

/media/uploads/dfraj/kotac.jpg

BLDCmotorDriver.cpp

Committer:: avilei
Date:: 2016-10-12
Revision:: 4:f56d1fb53d9b
Parent:: 3:a4b4a8e3f2a0

File content as of revision 4:f56d1fb53d9b:

#include "BLDCmotorDriver.h"

BLDCmotorDriver::BLDCmotorDriver(PinName pGH_A, PinName pGH_B, PinName pGH_C, PinName pGL_A, PinName pGL_B, PinName pGL_C,
                    PinName pH1, PinName pH2, PinName pH3, PinName pFault) : 
                    GH_A(pGH_A), GH_B(pGH_B), GH_C(pGH_C), GL_A(pGL_A), GL_B(pGL_B), GL_C(pGL_C),
                    H1(pH1), H2(pH2), H3(pH3), Fault(LED1){
                     
    sampleTime = 1e-3;
    switchingPeriod = 1.0 / 20e3;
    dutyCycle = tempDutyCycle = 0;
    GH_A.period(switchingPeriod); // applies to all PwmOut instances
    rl.setLimits(0.1, -0.1, 0, sampleTime); // initial 10 second ramp
    //H1.mode(PullNone);
    //H2.mode(PullNone);
    //H3.mode(PullNone);
    H1.rise(this, &BLDCmotorDriver::commutation);
    H2.rise(this, &BLDCmotorDriver::commutation);
    H3.rise(this, &BLDCmotorDriver::commutation);
    H1.fall(this, &BLDCmotorDriver::commutation);
    H2.fall(this, &BLDCmotorDriver::commutation);
    H3.fall(this, &BLDCmotorDriver::commutation);
}
void BLDCmotorDriver::configure(float sampleTime, float switchingFrequency, float rampUpSlope, float rampDownSlope) {
    if (sampleTime < 1e-6)
        sampleTime = 1e-3;
    if (switchingFrequency < 100)
        switchingFrequency = 20e3;
    if (rampUpSlope < 0 || rampUpSlope > 1)
        rampUpSlope = 0.1;
    if (rampDownSlope > 0 || rampDownSlope < -1)
        rampDownSlope = -0.1;
    this->sampleTime = sampleTime;
    switchingPeriod = 1.0 / switchingFrequency;
    rl.setLimits(rampUpSlope, rampDownSlope, 0, sampleTime);
}
int BLDCmotorDriver::getSector(){           // hall 120°
    
    h1 = H1.read();  
    h2 = H2.read();
    h3 = H3.read();
    
     
    if(h1 == 0 && h2 == 0 && h3 == 1){          
            _currentSector = 0;
             }    
    else if(h1 == 0 && h2 == 1 && h3 == 1){
            _currentSector = 1;        
            }        
    else if(h1 == 0 && h2 == 1 && h3 == 0){  
            _currentSector = 2;       
            }  
    else if(h1 == 1 && h2 == 1 && h3 == 0){
            _currentSector = 3;
            } 
    else if(h1 == 1 && h2 == 0 && h3 == 0){
            _currentSector = 4;
            }
    else if(h1 == 1 && h2 == 0 && h3 == 1){
            _currentSector = 5;
            }           
     previousSector = _currentSector - 1;
     difference = _currentSector - previousSector;
     if (difference == 1){
       currentSector = _currentSector;
       Fault = 0;
       }
     else Fault = 1; 
return currentSector;                
}  

void BLDCmotorDriver::commutation()  {
 dutyCycle = rl.out(tempDutyCycle);
 currentSector = getSector();
    if (dutyCycle > 0) {
        currentSector++;
        if(currentSector > 5)currentSector = 0;
        switch(currentSector) {  
        
          case 0:               //001     
                GH_A = dutyCycle;
                GL_A = 0;
                GH_B = 0;
                GL_B = 0;
                GH_C = 0;
                GL_C = 1;
                break;
           case 1:            
                GH_A = 0;
                GL_A = 0;
                GH_B = dutyCycle;
                GL_B = 0;
                GH_C = 0;
                GL_C = 1; 
                break;
           case 2:             
                GH_A = 0;
                GL_A = 1;
                GH_B = dutyCycle;
                GL_B = 0;
                GH_C = 0;
                GL_C = 0;
                break;
            case 3:             
                GH_A = 0;
                GL_A = 1;
                GH_B = 0;
                GL_B = 0;
                GH_C = dutyCycle;
                GL_C = 0;
                break;
            case 4:              
                GH_A = 0;
                GL_A = 0;
                GH_B = 0;
                GL_B = 1;
                GH_C = dutyCycle;
                GL_C = 0; 
                break;    
            case 5:              
                GH_A = dutyCycle;
                GL_A = 0;
                GH_B = 0;
                GL_B = 1;
                GH_C = 0;
                GL_C = 0; 
                break;
        }
    } else if (dutyCycle < 0) { 
        currentSector--;
        if(currentSector < 0)currentSector = 5;
        switch(currentSector) {
          case 0:              
                GH_A = -dutyCycle;
                GL_A = 0;
                GH_B = 0;
                GL_B = 1;
                GH_C = 0;
                GL_C = 0; 
                break;
          case 1:                 
                GH_A = -dutyCycle;
                GL_A = 0;
                GH_B = 0;
                GL_B = 0;
                GH_C = 0;
                GL_C = 1;
                break;
           case 2:            
                GH_A = 0;
                GL_A = 0;
                GH_B = -dutyCycle;
                GL_B = 0;
                GH_C = 0;
                GL_C = 1; 
                break;
           case 3:             
                GH_A = 0;
                GL_A = 1;
                GH_B = -dutyCycle;
                GL_B = 0;
                GH_C = 0;
                GL_C = 0;
                break;
            case 4:             
                GH_A = 0;
                GL_A = 1;
                GH_B = 0;
                GL_B = 0;
                GH_C = -dutyCycle;
                GL_C = 0;
                break;
            case 5:              
                GH_A = 0;
                GL_A = 0;
                GH_B = 0;
                GL_B = 1;
                GH_C = -dutyCycle;
                GL_C = 0; 
                break;    
                }                
        }else {
        coast();
    }
}
void BLDCmotorDriver::setDutyCycle(float dc) {
    if (dc >= -1 && dc <= 1) {
        ticker.attach(this, &BLDCmotorDriver::commutation, sampleTime);
        tempDutyCycle = dc;
    } else {
        coast();
    }
}
/*void BLDCmotorDriver::adjustDutyCycle() {
    dutyCycle = rl.out(tempDutyCycle);
    float diff = tempDutyCycle - dutyCycle;
    if (diff < 0.01 || diff > -0.01)
        ticker.detach();
}*/
void BLDCmotorDriver::coast() {
    GH_A = 0;
    GL_A = 0;
    GH_B = 0;
    GL_B = 0;
    GH_C = 0;
    GL_C = 0;
    dutyCycle = tempDutyCycle = 0;
    rl.reset();
    ticker.detach();
}
float BLDCmotorDriver::getDutyCycle() {
    return dutyCycle;
}