The influence of carrier frequency on the output secondary current waveform of the inverter

The size of the carrier frequency directly affects the quality of the current waveform and the size of the interference. Therefore, during operation, the carrier frequency value must be correctly selected first, and then various additional harmonic suppression devices, such as AC reactors, DC reactors, filters, zero-sequence reactors, installation wiring, grounding and other measures, must be considered. This is a very important principle. When the carrier frequency is high, the current waveform is sinusoidal and smooth, so the harmonics are small and the interference is small. Otherwise, it is bad. When the carrier frequency is too low, the effective torque of the motor decreases, the loss increases, and the temperature increases. On the contrary, if the carrier frequency is too high, the inverter's own loss increases, the ICBT temperature rises, and the output voltage change rate du/dt increases, which has a greater impact on the insulation of the motor, see the table.