University of Twente Student Theses
Energy Recuperation between DC Motors using Dynamically Reconfigurable Switch Grid
Wilbrink, E.J.J. (2024) Energy Recuperation between DC Motors using Dynamically Reconfigurable Switch Grid.
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| Abstract: | Energy saving in industrial robotics can directly contribute to reaching climate goals, as well as reducing operating costs. Several methods exist for this, for example regenerative braking, where braking energy from motors is recuperated and reused to accelerate motors again. This report proposes a novel regeneration method where motors are directly connected to each other to share and reuse their energy. The benefits and drawbacks of this method are investigated, and it is found to be favourable over conventional capacitor-based regeneration because it does require adding additional components to the system, which increases the size, weight and cost. A setup is designed and implemented to evaluate the main advantage the proposed motor-to-motor regeneration might have: reduced power consumption. The design requires an interconnection of switches to dynamically connect the various power sources and consumers. Several interconnect topologies are compared, and finally, a minimal crossbar topology is chosen for the design. The interconnect also generates a PWM signal to control the speed of the motors. The maximum frequency for this was found to be 10Hz limited by the speed of the switches in the interconnect and by the I2C busses used to control the switches from the microcontroller that was also included in the system. After calibrating the voltmeters and motor constants for the experimental setup, the efficiency of the system was measured. The experiments showed that motor-to-motor regeneration improved the system's power efficiency by up to 30%, or even up to 33% when combined with capacitor regeneration, whereas capacitor regeneration alone only yielded an improvement of 15%. However, even with regeneration, the system was still significantly less efficient than a state-of-the-art motor controller, but it seems reasonable to believe that adding the regeneration methods discussed in this report would further allow for further power savings. Looking at the results in more detail, motor-to-motor regeneration was found to be ineffective when the motors are in-phase and most effective when they are in anti-phase. Capacitor regeneration does not have this dependency on phase shift. Furthermore, regeneration brings a larger reduction when the motors are storing much energy and have high voltage. Besides, when the period of the waveform increases, the power usage gets lower independent of regeneration used because keeping the motors running at constant speed requires less energy than accelerating or decelerating them. Finally, it is found that using motor-to-motor regeneration causes the motors to accelerate and brake slower. |
| Item Type: | Essay (Master) |
| Faculty: | EEMCS: Electrical Engineering, Mathematics and Computer Science |
| Subject: | 50 technical science in general, 52 mechanical engineering, 53 electrotechnology, 54 computer science |
| Programme: | Embedded Systems MSc (60331) |
| Link to this item: | https://purl.utwente.nl/essays/103388 |
| Export this item as: | BibTeX EndNote HTML Citation Reference Manager |
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