写一个基于tms320f28355的三相逆变程序

以下是一个基于tms320f28355的三相逆变程序的示例代码。这个程序可以控制一个三相逆变器，将直流电压转换为交流电压。

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

#define PWM_PERIOD 4500

#pragma CODE_SECTION(epwm1_isr, "ramfuncs");

Uint16 CMPA1, CMPA2, CMPA3;

interrupt void epwm1_isr(void)
{
    EPwm1Regs.CMPA.half.CMPA = CMPA1;
    EPwm2Regs.CMPA.half.CMPA = CMPA2;
    EPwm3Regs.CMPA.half.CMPA = CMPA3;
    EPwm1Regs.ETCLR.bit.INT = 1;
    PieCtrlRegs.PIEACK.all = PIEACK_GROUP3;
}

void InitEPwm()
{
    EALLOW;
    CpuSysRegs.PCLKCR2.bit.EPWM1 = 1;
    CpuSysRegs.PCLKCR2.bit.EPWM2 = 1;
    CpuSysRegs.PCLKCR2.bit.EPWM3 = 1;
    EDIS;

    EPwm1Regs.TBCTL.bit.PRDLD = TB_IMMEDIATE;
    EPwm1Regs.TBPRD = PWM_PERIOD;
    EPwm1Regs.TBCTL.bit.CTRMODE = TB_COUNT_UPDOWN;
    EPwm1Regs.TBCTL.bit.PHSEN = TB_DISABLE;
    EPwm1Regs.TBCTL.bit.SYNCOSEL = TB_CTR_ZERO;
    EPwm1Regs.CMPCTL.bit.SHDWAMODE = CC_SHADOW;
    EPwm1Regs.CMPCTL.bit.LOADAMODE = CC_CTR_ZERO;
    EPwm1Regs.CMPA.half.CMPA = 0;
    EPwm1Regs.AQCTLA.bit.CAU = AQ_SET;
    EPwm1Regs.AQCTLA.bit.CAD = AQ_CLEAR;

    EPwm2Regs.TBCTL.bit.PRDLD = TB_IMMEDIATE;
    EPwm2Regs.TBPRD = PWM_PERIOD;
    EPwm2Regs.TBCTL.bit.CTRMODE = TB_COUNT_UPDOWN;
    EPwm2Regs.TBCTL.bit.PHSEN = TB_DISABLE;
    EPwm2Regs.TBCTL.bit.SYNCOSEL = TB_SYNC_IN;
    EPwm2Regs.CMPCTL.bit.SHDWAMODE = CC_SHADOW;
    EPwm2Regs.CMPCTL.bit.LOADAMODE = CC_CTR_ZERO;
    EPwm2Regs.CMPA.half.CMPA = 0;
    EPwm2Regs.AQCTLA.bit.CAU = AQ_SET;
    EPwm2Regs.AQCTLA.bit.CAD = AQ_CLEAR;

    EPwm3Regs.TBCTL.bit.PRDLD = TB_IMMEDIATE;
    EPwm3Regs.TBPRD = PWM_PERIOD;
    EPwm3Regs.TBCTL.bit.CTRMODE = TB_COUNT_UPDOWN;
    EPwm3Regs.TBCTL.bit.PHSEN = TB_DISABLE;
    EPwm3Regs.TBCTL.bit.SYNCOSEL = TB_SYNC_IN;
    EPwm3Regs.CMPCTL.bit.SHDWAMODE = CC_SHADOW;
    EPwm3Regs.CMPCTL.bit.LOADAMODE = CC_CTR_ZERO;
    EPwm3Regs.CMPA.half.CMPA = 0;
    EPwm3Regs.AQCTLA.bit.CAU = AQ_SET;
    EPwm3Regs.AQCTLA.bit.CAD = AQ_CLEAR;

    EPwm1Regs.ETSEL.bit.INTSEL = ET_CTR_ZERO;
    EPwm1Regs.ETSEL.bit.INTEN = 1;
    EPwm1Regs.ETPS.bit.INTPRD = ET_1ST;
}

void SetPWM(float Vdc, float Va, float Vb, float Vc)
{
    CMPA1 = (Uint16)((Vdc / 2 + Va) / Vdc * PWM_PERIOD);
    CMPA2 = (Uint16)((Vdc / 2 + Vb) / Vdc * PWM_PERIOD);
    CMPA3 = (Uint16)((Vdc / 2 + Vc) / Vdc * PWM_PERIOD);
}

void main()
{
    InitEPwm();
    SetPWM(100, 50, 0, 50); // 100V DC, 50V AC on phase A, 50V AC on phase C
    while (1) {}
}

这个程序使用了 DSP2833x 库中的 EPWM 模块来生成三相逆变器的 PWM 信号。在 `InitEPwm` 函数中，我们对 EPWM1，EPWM2 和 EPWM3 进行了初始化，并设置了 PWM 信号的周期为 4500 个时钟周期。在 `SetPWM` 函数中，我们计算出了三个 PWM 信号的占空比，然后分别设置了 CMPA1，CMPA2 和 CMPA3 寄存器的值。在 `main` 函数中，我们调用 `SetPWM` 函数来设置 PWM 信号的占空比，然后程序进入一个无限循环。

当程序运行时，EPWM 模块会生成三个 PWM 信号，这些信号将被用于控制三相逆变器的输出。三个 PWM 信号的占空比可以通过调用 `SetPWM` 函数进行设置。在示例代码中，我们设置了一个 100V 的直流电压，并将其中 50V 的交流电压分别施加在 A 相和 C 相上，从而产生了一个相位差为 120 度的三相交流输出。