thbt86, Your diagram has several problems.

• You can't reference actual frequency or voltage in the Volt/Hertz Profile block. You must use a fraction of full scale frequency and voltage. So if your max voltage at 100% duty cycle is 380V, and you want to start at 220V at the low frequency point, you use 220/380 = .579 at V at Low Freq Point. If your high frequency is 50Hz, and low freq is 20 Hz, your low freq point is 20/50 or 0.4 . Slope is (VhighPU-VlowPU)/(fHighPU-fLowPU). I have attached an updated diagram with proper settings and calculation of Per Unit values. (You may need to download the latest VisSim/ECD to get the proper slope scaling)
• You switched from Full Compare PWM to the "Space Vector" PWM. You did not connect the period scaling pin, so the period is set to zero. Also, you can't set the deadband with the "Space Vector" PWM, and you have an IGBT, which requires deadband setting. For that reason I recommend using the Full Compare.

You can download the updated V/Hz 50Hz diagrams below.

Hello

I am the french tech support of VisSim. Can you please give me more informations. As far as I understood your problem, you have simulation problems with your diagram. I downloaded it and it works fine. But it is a simulation diagram, it is not dedicated for dsp control. If you use a dsp in emulation mode, you must know that the JTAG is very slow, and at 50Hz, it does not give any accuracy. If you need faster transfer protocol, you must embed in your diagram Monitor buffers, in order to get fast informations on your screen.

I am sorry no to have understood all, please give me some more information, send the complete diagram, with your I/O, screen shots... and we will help you the best we can.

Regards

The acim_vf_openloop.vsm files below will correctly perform open-loop V/F control of a 3 phase AC induction motor. Your .bmp above does not give enough information to say if it is correct for your inverter topology. You must properly connect the LF2407 PWM pins to your IGBT drivers in the correct way. However, I updated the acim_vf_openloop.vsm files below to include an enable pin. This means that the PWM outputs will be in a high impedance state until you click the enable button. This lets you download and start the LF2407 with PWM in high impedance state. Then you can turn on the PWMs to test the the inverter and switch them off quickly if it starts to smell bad or catches fire.

The PWM block takes a fractional value between 0 and 1 on each of the 3 input pins. The input will control the duty cycle of the PWM. Yes, the hardware output of the PWM has only 2 levels, 0 (off) and 1 (on), but power is modulated by controlling the amount of on-time. The space vector wave form block produces values between +1 and -1. The PWM block needs values between 0 and 1, so the scaling maps the +1/-1 to 0/1. Without the mapping you will get wrong PWM response and a bad smell from the inverter as random signals are sent to it.

thank you very much for reply to me. i downloaded attach file but i don't understand something about it. why must gain 65 the output rotor angular, gain 25 in svggain. if i complie and load to DSP, it can generate signal PWM on DSP? or must i add fullcomparePWM block to control modune PWM on dsp kit. i'd finish a diagram use SVPWM control v/f ACI. can you give me some advise about it.