Hi everyone,
I am using a TMS320f28377d DSP module for my system (multilevel inverter) which requires generating 24 PWM signals. The good thing in this DSP is that it can generate 24 PWM signals. I am using 8 PWM signals per phase. There is a 120 degree phase shift between the three phases and this by default is done because of the reference signals (Va_ref, Vb_ref, and Vc_ref). I want to make a 180 phase shift between two signals in each phase. For example between PWM#1 and PWM#10.
By referring to the manual I am using the following code:
// Setup Phase
EPwm1Regs.TBPHS.bit.TBPHS = 0. ; // Phase is 0 degree
EPwm1Regs.TBCTL.bit.PHSEN = TB_DISABLE; // Disable phase loading
EPwm10Regs.TBPHS.bit.TBPHS = PwmPeriod * 0.5 ; // Phase is 180 degree
EPwm10Regs.TBCTL.bit.PHSEN = TB_ENABLE; // Enable phase loading
The 0.5 index indicates the phase shift is 180. However, my signals are not 180 inverted. I hope you share your knowledge if you have some answers to my concern. Thank you in advance.
Hello Samer,
Instead of PWM1_duty_A try using 1-PWM1_duty_A.
Here PWM1_duty_A is the normalized duty cycle value sent to PWM1 A.
You may try doing this before sending the reference signal to the PWM peripheral.
Cheers.