Energieoptimierte Antriebskonzepte für hydraulische Umformmaschinen mit elektrischen Servoantrieben

Within the project a real test machine has been equipped with widespread measurement instrumentation for the determination of physical quantities. These include electrical quantities of the power supply as well as measured variables describing the hydraulic and mechanical behavior of the machine. Additional state variables out of the control system round the holistic view on the behavior of the machine. The various forming processes examined at this test rig were carried out with several different configurations of the drive train. These include for example the combination between a motor of adjustable speed together with a pump of constant displacement, the combination between a motor of constant speed with pump of an adjustable displacement or the combination of variable-speed servomotor with a variable-displacement pump. The combinations have been compared among one another considering their energy efficiency. For the last combination, called variable-variable, an optimization algorithm has been developed due to the available additional degree of freedom. This additional degree of freedom in combination with the algorithm enables the drive train to stay in an optimal operating point during the entire process which significantly lowers the energy consumption of the press. In addition to these proven energy savings and thus savings of operating costs for the press operator a reduction of the size of the drive components is possible by introduction of an additional degree of freedom. This could lead to additional savings in investment costs for press manufacturers and operators. Furthermore, the proposed algorithm can be evolved to become directly integrated into the control of the pump which would add another unique feature for the pump manufacturer and increase its competitiveness. The objectives of the project to determine the energetic potential through the use of servo drives in hydraulic forming machines were thereby achieved completely