can u provide the model related to space vector pwm???

we are the license holder of vissim software(crescent engg.college).. we are currently working with the model and analysis of space vector pwm inverter.we are unable to run permanent magnet synchronous motor with the pulse got from space vector quadrature control block.. kindly help us with the correct model of svpwm..

Ahh. You have an AC Induction motor

I thought you had a PMSM. Here is an open loop diagram to control an induction motor along with a pure simulation of ACIM speed control.

further clarification in svpwm

thank u sir! finally our motor started to run smoothly but we find, whenever we suddenly decreases the values of amplitude and frequency using sliders, we found that our motor started to rotate in opposite direction(i.e in anti-clock wise, if it is runs in clockwise).. can you tel us why our motor(induction motor with sensor) changes it's direction of rotation when we changes the values???

poornima

further clarification regarding the space vector model

sir we got the model but as we are using vissim version7.0 we where unable to access the outfile........can u send us the entire outfile blocks......... and also we got the pulse but the supply voltage is very less......is there any provision to increase the supply voltage magnitude..............

poornima

The diagrams have been replaced with version 7

However if you just continue past the warning, the v8 diagrams would have worked fine. There is no way to extend a PWM past 100% duty cycle. If the voltage you are getting is insufficient, you'll have to take this up with your inverter hardware provider. Note that you MUST compile the "Open Loop PMSM control" subsystem with the Include VisSim Communication Interface option to generate the .out file, and then run the svpwm12-2812-d.vsm diagram to spin your motor. While you can run the svpwm12-2812.vsm diagram, the JTAG link is too slow to spin the motor.

Please send us your diagram

Tell us about your motor and inverter. Is this the sensorless one from TI? If so, you can download a working diagram from here. If it is from VI Micro, they should be able to help you as they have used VisSim to control their PMSM motor.

Ok, if you are signed in you will see two files for open loop PMSM control below. There were several problems with your diagram:

  • Your sample rate was 100 Hz, we find 10kHz is good for smooth control
  • Your Ramp output frequency was 50kHz. Your control loop must sample > 10X faster than the ramp to get smooth ramp signal. This is a Nyquist sampling rate issue. We have changed the top ramp frequency to 50 Hz.
  • You must scale the output from the Space Vector DQ wave form generator from +/-1 to 0 .. 1 before connecting to the Full Compare output
  • You set the inverse park Q input to 0, and varied the D with a slider. We have set D to 0 and let you vary Q with a slider. D is for the direct phase aligned with the rotor, Q is for the quadrature phase at 90 degrees to the rotor. In the normalized "360 deg = 1" units of the TI block set, use .25 as the nominal value to the Q input.