An elevator system and associated method includes power control for operating an elevator (2) in an emergency mode wherein the elevator (2) includes a car (4), a drive motor (10), a motor drive unit (26) which supplies power to the drive motor (10) and controls the same and an emergency power supply (42). The motor drive unit (10) has a predetermined normal operation switching frequency. In an emergency mode, power is supplied to the motor from the emergency power supply (42) while the motor drive unit is in an emergency mode. An actual emergency operation condition characteristic is determined for setting the switching frequency of the motor drive unit (46) dependent on the actual emergency operation condition characteristic.