Patent Number: 055815863
Section: claims

1. A drive device for control rod drive mechanisms for driving control rods of an atomic power plant, each drive mechanism including an electric motor drive, the drive mechanisms being divided into a plurality of groups, the device comprising: a control rod changeover device provided for each group of control rod drive mechanisms;  an inverter power source, associated with each said control rod changeover device, to provide a drive power source for said electric motor drives;  an inverter controller, for each said inverter power source, to output control signals for controlling said inverter power source;  a control device coupled to receive control rod position signals from each of said control rod drive mechanisms and to output control signals to each said control rod changeover device and inverter controller; and  a man-machine device to interface with an operator, the man-machine device for outputting control rod drive information to said control device.  wherein the man-machine device includes means for providing a selected mode signal to cause ganged mode operation;  the control device including:  the control rod selection unit responsive to the selected mode signal to provide a control rod changeover device signal to said inverter power source selection unit and a selected one of said control rod changeover devices associated with the selected control rod drive mechanism. 2. A drive device for control rod drive mechanisms according to claim 1, wherein in a ganged mode of operation, a selected control rod drive mechanism in each of the plurality of groups is operated; 3. A drive device for control rod drive mechanisms according to claim 1, wherein on full insertion of all the control rods, in the plurality of groups of control rod drive mechanisms, the control rod changeover device for each of these plurality of groups selectively couples the associated inverter power source to successive single control rod drive mechanisms. 4. A drive device for control rod drive mechanisms according to claim 1, wherein said control rods are separated from said electric motor drives and the control rods are inserted by water pressure, when reacter scram occurs. 5. A drive device for control rod drive mechanisms according to claim 1, wherein the control device includes means for operating the control rod drive mechanisms to a fully inserted position when a reactor scram occurs. 6. A drive device for control rod drive mechanisms according to claim 1, wherein said control rod changeover device is provided for each group of the control rod drive mechanisms. 7. A drive device for control rod drive mechanisms according to claim 1, wherein said control device comprises a drive control rod selection means to output control signals to said control rod changeover device. 8. A drive device for control rod drive mechanisms according to claim 1, wherein said control device comprises an inverter power source selection means to output control signals to said inverter controller. 9. A drive device for control rod drive mechanisms according to claim 8, wherein said control device comprises a control rod drive mechanism information evaluation means to output control signals to said inverter power source selection means. 10. A drive device for control rod drive mechanisms according to claim 7, wherein said man-machine device includes means to output control signals to said drive control rod selection means. 11. A drive device for control rod drive mechanisms according to claim 9, wherein said man-machine device includes means to output control signals to said control rod drive mechanism information evaluation means. 12. A drive device for control rod drive mechanisms according to claim 1, wherein said inverter power source is coupled to one of a conventional power source and a stand-by power source. 13. A drive device for control rod drive mechanisms according to claim 1, wherein said man-machine device is operated to select one of a control rod selection mode, a control rod drive mode, and a control rod insertion/withdrawal mode.