Design Features of the Frequency-Controlled Electric Drive for Positioning Mechanisms

Design Features of the Frequency-Controlled Electric Drive for Positioning Mechanisms

연구 분야: Infrastructure

학회: International Conference on High-Performance Computing Systems and Technologies in Scientific Research, Automation of Control and Production

The paper is devoted to the design peculiarities of the frequency-controlled electric drive of the hydraulic distributor of the ultra-high pressure hydraulic press. It justifies the need to power the windings of an induction motor (IM) with a short-circuit rotor from the output of a direct frequency converter (DFC) assembled according to a symmetrical scheme using six-pulse or three-pulse thyristor transducers. The paper also shows the method of the electric drive synthesis for positioning mechanisms, including the press hydraulic distributor, as well as the need to build a three-circuit system of subordinated coordinate control for the frequency-controlled electric drive of the hydraulic distributor. Unlike positioning DC electric drives the synthesis of the torque inner circuit in a frequency-controlled electric drive is significantly different, the features of which are described in detail in the paper. As a result of the measures taken, the required dynamic characteristics of the electric drive are provided in the torque circuit, the required processing time of the alignment is ensured in the speed loop, and the required accurate positioning of the working element is achieved in the position circuit. The study demonstrates the method when currents are generated in the AC stator windings with adjustable frequency, amplitude and phase by supplying sine signals from the output of the microprocessor generator to the inputs of the control system of the DFC power units. The paper shows the adjustment method, when the input of the torque regulator of the positive feedback, as well as its critical setting, is provided to the electric drive of the torque source property. The results of the synthesis of the electric drive control system are confirmed by a widely proposed experiment on the industrial model of the hydraulic distributor of the 30,000-ton press. Practical recommendations are formulated for the selection of rational power circuit layout diagrams of the direct frequency converter-induction motor system, as well as the principles for building an electric drive control system, which can be used in the design of the automation process with the participation of AC electric drives of positioning mechanisms.