Design and Development of Two Axis Control and Drive for PMSM Motor of In-Service Inspection Module for PFBR Steam Generator

The accuracy of the servo system is dependent on the speed or band width of the closed loop control system. To achieve the high speed closed loop operation, hardware oriented control is preferred and it is achieved by means of an ASIC (Application Specific Integrated Chip). The servo system is used to drive a two axis robotic arm moving in a plane where two PMSM motor with servo control provides the required motion. Robotic applications require quick and accurate changes in driving torque so that the required motion behaviour is attained. Quick change in operating flux is required for fast and accurate servo control. Conventional scalar control drives cannot achieve quick response time and hence vector control is employed. The IRMCK201 ASIC used in the application has the Vector Control algorithm hard wired into it for complete servo control of a single PMSM. It takes the position and current feed back by using shaft encoder, hall sensor and IR2175 Current sensing IC. It can set up communication with a host controller through either high speed serial, SPI or Parallel protocols. The inverter unit is implemented using an Intelligent Power Module (IPM) and it is driven by the Space Vector Modulation signals from IRMCK201. The work shows that highly efficient servo drive can be implemented using IRMCK201 and Host controller with PMSM.