F28035 三相 SPWM程序

以下是基于F28035芯片的三相SPWM程序的示例代码：

#include "DSP2833x_Device.h"
#include "DSP2833x_Examples.h"

#define PWM_FREQUENCY 10000
#define PI 3.14159265358979323846

volatile struct EPWM_REGS *ePWM[] = {&EPwm1Regs, &EPwm2Regs, &EPwm3Regs};

void InitEPwm()
{
    int i;
    for (i = 0; i < 3; i++)
    {
        (*ePWM[i]).TBCTL.bit.CTRMODE = TB_COUNT_UP;
        (*ePWM[i]).TBCTL.bit.PHSEN = TB_DISABLE;
        (*ePWM[i]).TBCTL.bit.SYNCOSEL = TB_CTR_ZERO;
        (*ePWM[i]).TBCTL.bit.HSPCLKDIV = TB_DIV1;
        (*ePWM[i]).TBCTL.bit.CLKDIV = TB_DIV1;
        (*ePWM[i]).TBPRD = (int)((SYSCLKOUT / (PWM_FREQUENCY * 2)) - 1);
        (*ePWM[i]).CMPA.bit.CMPA = (*ePWM[i]).TBPRD / 2;
        (*ePWM[i]).CMPB.bit.CMPB = (*ePWM[i]).TBPRD / 2;
        (*ePWM[i]).CMPCTL.bit.SHDWAMODE = CC_SHADOW;
        (*ePWM[i]).CMPCTL.bit.SHDWBMODE = CC_SHADOW;
        (*ePWM[i]).CMPCTL.bit.LOADAMODE = CC_CTR_ZERO;
        (*ePWM[i]).CMPCTL.bit.LOADBMODE = CC_CTR_ZERO;
        (*ePWM[i]).AQCTLA.bit.CAU = AQ_CLEAR;
        (*ePWM[i]).AQCTLA.bit.CAD = AQ_SET;
        (*ePWM[i]).AQCTLB.bit.CBU = AQ_CLEAR;
        (*ePWM[i]).AQCTLB.bit.CBD = AQ_SET;
        (*ePWM[i]).DBCTL.bit.OUT_MODE = DB_FULL_ENABLE;
        (*ePWM[i]).DBCTL.bit.POLSEL = DB_ACTV_HIC;
        (*ePWM[i]).DBCTL.bit.IN_MODE = DBA_ALL;
        (*ePWM[i]).DBRED.bit.DBRED = 0;
        (*ePWM[i]).DBFED.bit.DBFED = 0;
        (*ePWM[i]).ETSEL.bit.SOCAEN = 0;
        (*ePWM[i]).ETSEL.bit.SOCASEL = ET_CTR_ZERO;
        (*ePWM[i]).ETPS.bit.SOCAPRD = ET_1ST;
    }
}

void SPWM(float Vref, float freq, float t)
{
    float theta, t_sample, V1, V2, V3;
    int i;

    for (i = 0; i < 3; i++)
    {
        theta = (float)i * 2.0 * PI / 3.0;
        t_sample = t + theta / freq;
        V1 = Vref * sin(2.0 * PI * freq * t_sample);
        V2 = Vref * sin(2.0 * PI * freq * t_sample - 2.0 * PI / 3.0);
        V3 = Vref * sin(2.0 * PI * freq * t_sample + 2.0 * PI / 3.0);

        if (V1 >= 0)
        {
            (*ePWM[i]).AQCTLA.bit.ZRO = AQ_SET;
            (*ePWM[i]).AQCTLA.bit.CAU = AQ_CLEAR;
        }
        else
        {
            (*ePWM[i]).AQCTLA.bit.ZRO = AQ_CLEAR;
            (*ePWM[i]).AQCTLA.bit.CAU = AQ_SET;
        }

        if (V2 >= 0)
        {
            (*ePWM[i]).AQCTLB.bit.ZRO = AQ_SET;
            (*ePWM[i]).AQCTLB.bit.CBU = AQ_CLEAR;
        }
        else
        {
            (*ePWM[i]).AQCTLB.bit.ZRO = AQ_CLEAR;
            (*ePWM[i]).AQCTLB.bit.CBU = AQ_SET;
        }

        if (V3 >= 0)
        {
            (*ePWM[i]).CMPA.bit.CMPA = (int)((float)(*ePWM[i]).TBPRD / 2.0 * (1.0 - V3 / Vref));
            (*ePWM[i]).AQCTLB.bit.CAD = AQ_SET;
        }
        else
        {
            (*ePWM[i]).CMPA.bit.CMPA = (int)((float)(*ePWM[i]).TBPRD / 2.0 * (1.0 + V3 / Vref));
            (*ePWM[i]).AQCTLB.bit.CAD = AQ_CLEAR;
        }
    }
}

void main()
{
    InitSysCtrl();
    InitEPwm();

    while (1)
    {
        float Vref = 220.0;
        float freq = 50.0;
        float t = 0.0;

        while (t < 1.0 / freq)
        {
            SPWM(Vref, freq, t);
            t += 1.0 / (PWM_FREQUENCY * 6.0);
            DELAY_US(100);
        }
    }
}

该程序实现了一个基于三角波的SPWM，包括初始化和SPWM函数。在SPWM函数中，计算了每个电平的电压并根据它们的符号设置PWM占空比。此外，根据每个电平的幅值调整了相应的PWM占空比，以产生所需的电压波形。

需要注意的是，该代码是一个简单的示例，可能需要根据具体应用进行修改和优化。