What is a possible consequence of setting the switching frequency of a power electronic for a DC machine to 2 kHz?

Setting the switching frequency of a power electronic device for a DC machine to 2 kHz can indeed lead to annoying noise. This is due to the way that power electronics operate. At lower switching frequencies, the system might produce audible noise, which is often a result of mechanical vibrations caused by the electromagnetic forces acting on the components. When the frequency falls within the range of human hearing, these vibrations can be perceived as annoying sounds.

On the other hand, while high switching frequencies contribute to improved efficiency by allowing more precise control of the power delivered to the motor, this advantage tends to occur at much higher frequencies. Increased heat generation can occur as the switching frequency increases due to higher losses in the devices used, but heat isn't strictly a result of lower frequencies like 2 kHz. Additionally, noise generally does not directly translate to decreased motor lifespan unless it leads to excessive vibration and fatigue, which is a more complex relationship.

Hence, the consequence of noise at a switching frequency of 2 kHz is a significant consideration in both design and operational phases and can affect user acceptance and overall satisfaction with the system.