An alternating current rotating machine control device provided with a function of communicating between a plurality of power conversion devices (11, 12, 13), that drive alternating current rotating machines (M1, M2, M3) at a predetermined speed, and one or more accompanying information instruments, the alternating current rotating machine control device comprising: a second communication means (23, 24) that connects the plurality of power conversion devices (11, 12, 13) to each other, and connects the plurality of power conversion devices (11, 12, 13) and the information instruments (14, 15) to each other, thereby maintaining the mutual linking thereof, wherein one of the power conversion devices is designated as a master station, whereby control status information held by all the power conversion devices and information instruments can be shared, and wherein the one of the power conversion devices designated as a master station is a specific power conversion device, characterized in that the alternating current rotating machine control device further comprises: a top level control device at a level above the power conversion devices (11, 12, 13) that issues various kinds of command to, or carries out a monitoring of, the power conversion devices (11, 12, 13) or the accompanying information instruments, wherein the accompanying information instruments are sensor instruments (14, 15); and a first communication means that connects the top level control device and the specific power conversion device, and transmits and receives a signal between the top level control device and the specific power conversion device; the top level control device designates in advance a plurality of the power conversion devices as candidates for the master station, and in the event that communication via the first communication means between the specific power conversion device and the top level control device becomes impossible, one of the remaining power conversion devices (12, 13) is changed to being the master station. a second communication means (23, 24) that connects the plurality of power conversion devices (11, 12, 13) to each other, and connects the plurality of power conversion devices (11, 12, 13) and the information instruments (14, 15) to each other, thereby maintaining the mutual linking thereof, wherein one of the power conversion devices is designated as a master station, whereby control status information held by all the power conversion devices and information instruments can be shared, and wherein the one of the power conversion devices designated as a master station is a specific power conversion device, characterized in that the alternating current rotating machine control device further comprises: a top level control device at a level above the power conversion devices (11, 12, 13) that issues various kinds of command to, or carries out a monitoring of, the power conversion devices (11, 12, 13) or the accompanying information instruments, wherein the accompanying information instruments are sensor instruments (14, 15); and a first communication means that connects the top level control device and the specific power conversion device, and transmits and receives a signal between the top level control device and the specific power conversion device; the top level control device designates in advance a plurality of the power conversion devices as candidates for the master station, and in the event that communication via the first communication means between the specific power conversion device and the top level control device becomes impossible, one of the remaining power conversion devices (12, 13) is changed to being the master station. a top level control device at a level above the power conversion devices (11, 12, 13) that issues various kinds of command to, or carries out a monitoring of, the power conversion devices (11, 12, 13) or the accompanying information instruments, wherein the accompanying information instruments are sensor instruments (14, 15); and a first communication means that connects the top level control device and the specific power conversion device, and transmits and receives a signal between the top level control device and the specific power conversion device; the top level control device designates in advance a plurality of the power conversion devices as candidates for the master station, and in the event that communication via the first communication means between the specific power conversion device and the top level control device becomes impossible, one of the remaining power conversion devices (12, 13) is changed to being the master station.