METHOD AND SYSTEM TO START MULTIPLE AC MOTORS SUPPLIED BY A POWER CONVERTER VIA A COMMON AC BUS

摘要

A method to start at least two AC motors that are supplied from a common AC bus, which in turn is supplied from a power converter. At least one of the AC motors is an electrically excited synchronous motor including an excitation circuit. The synchronous motor is started first. During starting of remaining of the at least two AC motors a reactive power supplied by the power converter is determined and an increase of a field current or of a field voltage of the synchronous motor in linear dependence on the reactive power supplied by the power converter is determined. The increased field current or field voltage is applied to the excitation circuit of the synchronous motor.