28035 EPWM使用Digital Compare Submodule设置封锁PWM输出

yanhui fu

用DSP28035 控制永磁同步电机做过流或短路保护，ADC模块的comparator模块的三个比较器的正向输入端，分别采样电机U、V、W三相电流，负向输入端使用内部的DAC，当出现过流时，三个比较器的的输出低电平触发EPWM封锁PWM输出。

现在问题是，当U相过流或短路时，COMP1OUT输出低电平，只能封锁U相EPWM1A和EPWM1B输出低电平。

当V相过流或短路时，COMP2OUT输出低电平，只能封锁V相EPWM2A和EPWM2B输出低电平。

当W相过流或短路时，COMP3OUT输出低电平，只能封锁W相EPWM3A和EPWM3B输出低电平。

我现在想当其中任何一相过流时，使6路PWM都输出低电平，怎么操作。

EPWM部分程序设置如下：

// Init PWM Digital Compare Control Register for EPWM1-EPWM3
EPwm1Regs.DCTRIPSEL.bit.DCAHCOMPSEL = DC_COMP3OUT; // DCAH = Comparator 3 output
EPwm1Regs.TZDCSEL.bit.DCAEVT1 = TZ_DCAH_LOW; // DCAEVT1 = DCAH low(will become active as Comparator output goes low)
EPwm1Regs.DCACTL.bit.EVT1SRCSEL = DC_EVT1; // DCAEVT1 = DCAEVT1 (not filtered)
EPwm1Regs.DCACTL.bit.EVT1FRCSYNCSEL = DC_EVT_ASYNC; // Take async path

EPwm1Regs.DCTRIPSEL.bit.DCBHCOMPSEL = DC_COMP3OUT; // DCBH = Comparator 3 output
EPwm1Regs.TZDCSEL.bit.DCBEVT1 = TZ_DCBH_LOW; // DCBEVT1 = DCBH low(will become active as Comparator output goes low)
EPwm1Regs.DCBCTL.bit.EVT1SRCSEL = DC_EVT2; // DCBEVT1 = DCBEVT1 (not filtered)
EPwm1Regs.DCBCTL.bit.EVT1FRCSYNCSEL = DC_EVT_ASYNC; // Take async path

// Init PWM Digital Compare Control Register for EPWM1-EPWM3
EPwm2Regs.DCTRIPSEL.bit.DCAHCOMPSEL = DC_COMP1OUT; // DCAH = Comparator 1 output
EPwm2Regs.TZDCSEL.bit.DCAEVT1 = TZ_DCAH_LOW; // DCAEVT1 = DCAH low(will become active as Comparator output goes low)
EPwm2Regs.DCACTL.bit.EVT1SRCSEL = DC_EVT1; // DCAEVT1 = DCAEVT1 (not filtered)
EPwm2Regs.DCACTL.bit.EVT1FRCSYNCSEL = DC_EVT_ASYNC; // Take async path

EPwm2Regs.DCTRIPSEL.bit.DCBHCOMPSEL = DC_COMP1OUT; // DCBH = Comparator 1 output
EPwm2Regs.TZDCSEL.bit.DCBEVT1 = TZ_DCBH_LOW; // DCBEVT1 = DCBH low(will become active as Comparator output goes low)
EPwm2Regs.DCBCTL.bit.EVT1SRCSEL = DC_EVT2; // DCBEVT1 = DCBEVT1 (not filtered)
EPwm2Regs.DCBCTL.bit.EVT1FRCSYNCSEL = DC_EVT_ASYNC; // Take async path

// Init PWM Digital Compare Control Register for EPWM1-EPWM3
EPwm3Regs.DCTRIPSEL.bit.DCAHCOMPSEL = DC_COMP2OUT; // DCAH = Comparator 2 output
EPwm3Regs.TZDCSEL.bit.DCAEVT1 = TZ_DCAH_LOW; // DCAEVT1 = DCAH low(will become active as Comparator output goes low)
EPwm3Regs.DCACTL.bit.EVT1SRCSEL = DC_EVT1; // DCAEVT1 = DCAEVT1 (not filtered)
EPwm3Regs.DCACTL.bit.EVT1FRCSYNCSEL = DC_EVT_ASYNC; // Take async path

EPwm3Regs.DCTRIPSEL.bit.DCBHCOMPSEL = DC_COMP2OUT; // DCBH = Comparator 2 output
EPwm3Regs.TZDCSEL.bit.DCBEVT1 = TZ_DCBH_LOW; // DCBEVT1 = DCBH low(will become active as Comparator output goes low)
EPwm3Regs.DCBCTL.bit.EVT1SRCSEL = DC_EVT2; // DCBEVT1 = DCBEVT1 (not filtered)
EPwm3Regs.DCBCTL.bit.EVT1FRCSYNCSEL = DC_EVT_ASYNC; // Take async path

// Init Trip Zone Select Register
// Enable DCAEVT1 and DCBEVT1 are one shot trip sources
// Note: DCxEVT1 events can be defined as one-shot.
// DCxEVT2 events can be defined as cycle-by-cycle.
EPwm1Regs.TZSEL.bit.DCAEVT1 = 1;
EPwm1Regs.TZSEL.bit.DCBEVT1 = 1;

EPwm2Regs.TZSEL.bit.DCAEVT1 = 1;
EPwm2Regs.TZSEL.bit.DCBEVT1 = 1;

EPwm3Regs.TZSEL.bit.DCAEVT1 = 1;
EPwm3Regs.TZSEL.bit.DCBEVT1 = 1;

// What do we want the DCAEVT1 and DCBEVT1 events to do?
// DCAEVTx events can force EPWMxA
// DCBEVTx events can force EPWMxB
EPwm1Regs.TZCTL.bit.TZA = TZ_FORCE_LO; // EPWM1A will go low
EPwm1Regs.TZCTL.bit.TZB = TZ_FORCE_LO; // EPWM1B will go low

EPwm2Regs.TZCTL.bit.TZA = TZ_FORCE_LO; // EPWM2A will go low
EPwm2Regs.TZCTL.bit.TZB = TZ_FORCE_LO; // EPWM2B will go low

EPwm3Regs.TZCTL.bit.TZA = TZ_FORCE_LO; // EPWM3A will go low
EPwm3Regs.TZCTL.bit.TZB = TZ_FORCE_LO; // EPWM3B will go low

10 年多前

0 Eric Ma 10 年多前

TI__Guru 60308 points

yanhui,

PWMx模块只要配置TZSEL > DCAEVT1 = 1, 并配置 DC模块利用COMPxOUT 产生DCAEVT1就可以产生TZ信号。通过配置TZCTL > TZA, TZCTL > TZB就可以拉低PWM输出。

假如可以只使用一个COMP1OUT作为这3个PWM模块的过流保护信号的话，就可以同时拉低这些PWM信号。可以使用一个总电阻的方式用来做过流保护。如下图，Isum为每路电流的总和，可以用来监控各相电流。

下面是相应的程序，仅做理解。

for(cnt=0;cnt<3;cnt++) {

// setup the Digital comparator DCTRIPSEL Register

//DCAH = Comparator 1 output,DCAL = TZ1

PWM_setDigitalCompareInput(obj->pwmHandle[cnt],PWM_DigitalCompare_A_High,PWM_DigitalCompare_InputSel_COMP1OUT); PWM_setDigitalCompareInput(obj->pwmHandle[cnt],PWM_DigitalCompare_A_Low,PWM_DigitalCompare_InputSel_TZ1);

// setup Digital comparator TZDCSEL Register

// DCAEVT1 on DCAH High (will become active as Comparator1 output goes High), DCAL = don't care

PWM_setTripZoneDCEventSelect_DCAEVT1(obj->pwmHandle[cnt],PWM_TripZoneDCEventSel_DCxHH_DCxLX); // 配置DCAEVT1的产生

}

void DRV_setupFaults(DRV_Handle handle)

{

DRV_Obj *obj = (DRV_Obj *)handle; uint_least8_t cnt;

for(cnt=0;cnt<3;cnt++)

{

PWM_enableTripZoneSrc(obj->pwmHandle[cnt],PWM_TripZoneSrc_CycleByCycle_TZ6_NOT);

PWM_enableTripZoneSrc(obj->pwmHandle[cnt],PWM_TripZoneSrc_OneShot_TZ1_NOT);

PWM_enableTripZoneSrc(obj->pwmHandle[cnt],PWM_TripZoneSrc_OneShot_CmpA); // 配置TZSEL > DCAEVT1

PWM_setTripZoneState_TZA(obj->pwmHandle[cnt],PWM_TripZoneState_EPWM_Low); // 配置TZCTL > TZA

PWM_setTripZoneState_TZB(obj->pwmHandle[cnt],PWM_TripZoneState_EPWM_Low); // 配置TZCTL > TZB

PWM_setTripZoneState_DCAEVT1(obj->pwmHandle[cnt],PWM_TripZoneState_DoNothing);

PWM_clearOneShotTrip(obj->pwmHandle[cnt]);

}

return;

} // end of DRV_setupFaults() function

Eric

C2000 微控制器

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28035 EPWM使用Digital Compare Submodule设置封锁PWM输出