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

摘要

pA method and a system are proposed to start at least two AC motors (SM, IM) which are supplied by a power converter (8) via a common AC bus (7). A synchronous motor (SM), which is one of the at least two AC motors, is started first. Afterwards, the reactive power (Q) of the power converter (8) is determined. A first control unit determines an increase of a field current (iSUBf/SUB) or of a field voltage (vSUBf/SUB) of the synchronous motor (SM) in linear dependence on the reactive power (Q) in the power converter. The increased field current (iSUBf/SUB) or field voltage (vSUBf/SUB) is then applied to an excitation circuit of the synchronous motor (SM)./p[WO2008110209A1]