Part Number: TMS320F2812
Has anybody seen that as a 3-phase inverter increases load that there is an offset between the 3 current waveforms? What have you done to combat it? I can run it to full speed at light load and I can load it at low speed. In the data below, you can see that I have a 3rd DCCT (current sensor) for phase C. The details of my test setup are that the motor is a PM motor, the DC voltage is 750V unloaded, the output current is 590 A RMS, the output frequency is 380 Hz (4500 rpm), and the switching frequency is 5.5 kHz. The control algorithm is a modified Field Oriented Control. I have changed my PI regulator parameters all over the place with no progress. The position is gathered from a Resolver to Digital Converter chip and is displayed as Theta in the graphs. It looks good.
In the graph, the x-axis is samples which are taken at the switching frequency and the y-axis current is in pu. The scale is 1500A.
Thanks for any suggestions!
