Low noise operation of a pulsed inverter fed motor.

摘要

The low noise system requires a pulse-controlled inverter with switching impulses generated by carrier modulation or rotating vector modulation. These are used to control the inverter switching elements, which generate the pulse pattern of the output voltage used to supply power to an electrical machine. The required pulse pattern is calculated as a mathematical function, in which the carrier modulation pulse frequency is sinusoidally varied to minimise or eliminate those overshoots which are disturbing to the human ear. Since the frequency of the fundamental component of the output voltage is independent of the modulation parameters, these can be varied without affecting operation of the machine.