This method for controlling an asynchronous electrical motor (32) of a compressor system (10), comprises:—connecting (100) a capacitor bank (50) of the compressor system (10) in parallel with a first electrical motor (32) of the compressor system, this connection comprising connecting capacitors (52, 54, 56) of the capacitor bank (50) to windings of the stator of the first motor (32), by operating a switch unit (60) of the capacitor bank connected to an internal power bus (12);—starting (102) the first asynchronous electrical motor (32), by providing an input electrical current to the windings of the first motor (32) from the internal power bus (12);—disconnecting (108) the capacitor bank (50) from said first motor (32) once said motor (32) has started, this disconnection comprising disconnecting said capacitors (52, 54, 56) from the windings of the motor (32).