Part Number: TMS320F28075
Tool/software:
Hi Team,
In the application of three-level ANPC wave transmission mode, the topology mode is 1 phase, and there are two sets of PWM for high-speed PWM and one group for low-speed PWM, where the low-speed PWM conversion level is consistent with the external power cycle of a given frequency, that is, when the external operation is 50Hz, the low-speed PWM switching period is 20ms.
The PWM configuration for one phase is as follows:
EALLOW;
CpuSysRegs.PCLKCR0.bit.TBCLKSYNC = 0;
EPwm1Regs.TBCTL.all = 0x0E012;
EPwm2Regs.TBCTL.all = 0x0E006;
EPwm9Regs.TBCTL.all = 0x0E006;
EPwm1Regs.CMPCTL.all = 0x0100;
EPwm2Regs.CMPCTL.all = 0x0100;
EPwm9Regs.CMPCTL.all = 0x0100;
EPwm1Regs.AQCTLA.all = 0x0090;
EPwm2Regs.AQCTLA.all = 0x0090;
EPwm9Regs.AQCTLA.all = 0x0090;
EPwm1Regs.AQCTLB.all = 0x0900;
EPwm2Regs.AQCTLB.all = 0x0900;
EPwm9Regs.AQCTLB.all = 0x0900;
EPwm1Regs.DBCTL.all = 0x0027;
EPwm2Regs.DBCTL.all = 0x0027;
EPwm9Regs.DBCTL.all = 0x0027;
CpuSysRegs.PCLKCR0.bit.TBCLKSYNC = 1;
EDIS;
The problem is as follows:
CH1 is PWM1A CH2 is PWM2A. CH3 is PWM1B. CH4 is the U-phase current, and the current is outwardly positive.
In the normal state, after the PWM is switched in Figure 1 above, CH2 changes from low to high, and PWM1 and PWM2 change at the same time.
Error case, when the external conditions change, there will be a situation in Figure 2 and 3 above, that is, PWM is assigned at the same time, but the actual change is not the same time, the change delay of test 2 and 3 is half a carrier period, and PWM is required to change at the same time in PWM1 and PWM2 regardless of whether it changes in 2 or 3.
