for an inverter PWM -ADC -feedback -synching
What is the best meathd to of feedback method In sineinverter (like commercial) ?
is it good by a forumal appling instead using look up rable .It saves the memory
If i use look up table
const unsigned char sin_table[416]={
0, 16, 32, 47, 62, 77, 91, 103, 115, 126, 136, 144, 151, 156, 160, 162, 163, 162, 160, 156, 151, 144, 136, 126, 115, 103, 91, 77, 62, 47, 32, 16, //65%
0, 17, 33, 49, 65, 80, 94, 107, 120, 131, 141, 149, 156, 162, 166, 168, 169, 168, 166, 162, 156, 149, 141, 131, 120, 107, 94, 80, 65, 49, 33, 17, //67.5%
Like wise if i use 25% ,26% 27% ...to 100% with having array value 256
there require a lot of memory (aproximately 256 *75 bytes )
is it good or any idea behind it ?
My second Question is
My PWM siganls drive an H-Bridge with a 16khz frequency ,where i get a sine wave with 50 hz after filtering .
I am trying to impliment a feedback with adc to correct the output voltage of the PWM.
How much speed require to variying the PWM dutycycle ? (adc conversion how to synch with pwm and adc)
which mean ADC reads in 1 micro second and changing the duty cycle is so fast
How can i calculate it ?
consider the above values are just taken for only example to understand the question .
Need to synchronize my sample rate with my switching rate to alias the high switching frequency component to DC and also compensate the whole filtering-adc-processing-spwm delay path in my digital implementation , if yes How to achive it .
Plseas excuse me my english