time_search
Junior Member level 3
good day... i did built the spwm and it is looking somehow better and after applying spwm on my 3-level d.c.i. cct, it is working better but the thd is not less than 40% which is the case without any type of modualtion..
i did use a modualtion index near 0.8 and a carrier frequeny 2khz. but THD was around 41.5%.
i was expecting a THD less than 40% especially i am, dealing with a non uniform pwm which is the spwm not the uniform pwm which is the multipulse pwm.
so i am thinking it might be the mosfet and i thought to replace it with sbreak switch which ideal and a freewheeling diode ideal one which is dbreak and that time when i tried to run the simulation it gave me this error:
ERROR-- subciruit schematic _s1 used by x_s1 is undefined
this error was for the 8 switches used in the cct>>>
could you please advise me...
i did use a modualtion index near 0.8 and a carrier frequeny 2khz. but THD was around 41.5%.
i was expecting a THD less than 40% especially i am, dealing with a non uniform pwm which is the spwm not the uniform pwm which is the multipulse pwm.
so i am thinking it might be the mosfet and i thought to replace it with sbreak switch which ideal and a freewheeling diode ideal one which is dbreak and that time when i tried to run the simulation it gave me this error:
ERROR-- subciruit schematic _s1 used by x_s1 is undefined
this error was for the 8 switches used in the cct>>>
could you please advise me...
