Servo system with a quasidirect converter

Fast electric drive systems like servo drives are characterized by high dynamic and precision as well as good control response. In the process automation industry, highly dynamic and precise handling systems are especially of importance. In the robot industry for fast loading and unloading operations and for transportation operations the drives predominantly used are modern servo drives. They have a compact design as well as offering high dynamic transmission of the motion with consistent repetition and system stability. The total system has to be considered with regard to the drive. The electronic and mechanical components of the frequency converter and the machine, the interaction between the power and signal electronics and last but not least the thermal behavior are all factors that influence the choice of drive. The necessary braking operations together with high-speed motions cause unwanted heat in the switched braking resistor of the drive system. By the use of a quasidirect converter with dynamic energy recovery, high temperatures in the converter systems will be avoided. The research of the IALB in the field of the quasidirect converter technology delivers practical laboratory results and testing routines for servo drives with rated power up to 10 kW. The experimental set-up of the quasidirect converter construction is presented on a test stand and the features of this converter type and the possibility of minimizing the volume and as well as the weight are examined. In addition, these types of converters permit a reduction of the number of parts as well as to reducing the generation of heat, the EMI filter size at the mains, and thus the costs.