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Die vorliegende Arbeit ist motiviert durch die breite Anwendung von Schwenkantrieben in vielfältigen konventionellen und neuen Technologiefeldern: In Windenergieanlagen führen Schwenkantriebe die Gondel samt Rotor der momentanen Windrichtung nach. Bei Radioteleskopen erlauben sie die hochpräzise azimutale Ausrichtung der Parabolantenne. Und im Sektor der Baumaschinen kommen sie zum Schwenken der Ausleger von Kranen und fördertechnischen Großgeräten zum Einsatz. Trotz des zunächst einfach erscheinenden Aufbaus der Schwenkantriebssysteme erweisen sich sowohl ihre mechanische Dimensionierung als auch ihre sichere Betriebsführung als herausfordernd. So belegen Messdaten und Betriebserfahrungen die Neigung der Antriebsstränge zu niederfrequenten Drehschwingungen. Außerdem treten große Spitzenlasten während der Schwenkrichtungsumkehr in den Getriebestufen auf. In diesem Forschungsbeitrag werden Methoden vorgestellt, mit denen elektromechanische Schwenkantriebssysteme modelliert, dynamisch analysiert und regelungstechnisch optimiert werden können. Dazu wird der schwingungsfähige mechanische Antriebsstrang eines Beispielschwenkwerks als detailliertes Mehrkörpersystem-Simulationsmodell abgebildet. Um auch Wechselwirkungen mit den elastischen Umgebungsstrukturen, der Antriebsregelung und den Betriebslasten zu erfassen, wird ein domänenübergreifendes Modellierungsvorgehen verfolgt. Es erfolgt eine messtechnische Validierung des mechatronischen Gesamtsystemmodells. Mit dem Vorliegen treffsicherer Systemmodelle eröffnet sich die Möglichkeit, ein modellbasiertes Mehrgrößenregelverfahren (LQG) auszulegen und simulativ zu erproben. Im Vergleich zur bisherigen proportional-integralen (PI) Antriebsregelung verspricht dies die aktive Dämpfung von Triebstrangschwingungen bei gleichzeitiger Erhöhung der Arbeitsgeschwindigkeit. Um für beliebige elastische Antriebssysteme das Optimierungspotenzial abschätzen zu können, erfolgt ein systematischer Vergleich der beiden Regelstrategien. Anschließend wird ein praxisnahes Vorgehen zur Regelungsauslegung vorgestellt. Besonderer Fokus liegt neben der Robustheit auch auf der begrenzten Anzahl verfügbarer Sensoren bei industriellen Antrieben. Zudem wird auch das oftmals beträchtliche Getriebespiel als signifikante Nichtlinearität der Regelstrecke berücksichtigt. Um eine Reduktion der Spitzenlasten während der Drehrichtungsumkehr des Schwenkantriebes zu erreichen, wird abschließend ein Konzept zur zeit- und belastungsoptimierten Durchquerung des Getriebespiels erarbeitet. Da die konventionelle Drehzahlregelung des Schwenkantriebs hierbei nur um ein Zusatzmodul erweitert wird, bietet sich das Vorgehen insbesondere zur Ertüchtigung bestehender Antriebe an.:1 Einleitung 1.1 Motivation 1.2 Konkretisierte Problemstellung 1.3 Aufbau der Arbeit 2 Grundlagen und Forschungsstand 2.1 Modellbildung und Simulation von Antriebssystemen 2.1.1 Mehrkörpersystem-Simulation von Antriebssystemen 2.1.2 Modellbildung von Schwenkwerken 2.2 Anwendungsbereiche von Schwenkantrieben 2.2.1 Turmdrehkrane 2.2.2 Windenergieanlagen 2.2.3 Radioteleskope 2.2.4 Baumaschinen 2.3 Untersuchtes Beispielschwenkwerk 2.3.1 Antriebstechnik 2.3.2 Bisherige Untersuchungen an Schaufelradbaggern 3 Modellbildung und Simulation von Schwenkwerken 3.1 Mechanische Komponenten 3.1.1 Schwenkantriebe 3.1.2 Elastische Tragstrukturen am Getriebeausgang 3.1.3 Weitere Antriebsstränge des Gesamtsystems 3.2 Elektrische und informationsverarbeitende Domäne 3.2.1 Aktorik – Elektrische Antriebsmaschine 3.2.2 Informationsverarbeitung – Antriebsregelung 3.2.3 Informationserfassung – Winkelmesssysteme 3.3 Betriebslasten 3.3.1 Quasistatische Lasten 3.3.2 Simulation der bodenmechanischen Interaktion bei Schaufelradbaggern 3.4 Messdatengestützte Validierung der Systemmodelle 3.4.1 Beschreibung des Messaufbaus 3.4.2 Betriebsschwingungsanalyse 3.4.3 Validierung Schwenkwerk – Reversiervorgang 3.4.4 Validierung Gesamtsystem – Grab-Schwenk-Prozess 3.5 Ableitung eines mechanischen Minimalmodells 3.6 Zwischenfazit 4 Drehzahlregelung elastischer Antriebssysteme 4.1 Allgemeine Grundlagen 4.1.1 Führungs- und Störungsverhalten 4.1.2 Stabilität und Performanz 4.1.3 Singulärwertzerlegung von Frequenzgangmatrizen 4.2 Motor mit elastisch gekoppeltem Abtrieb 4.2.1 Proportional-Integrale Eingrößenregelung 4.2.2 Zustandsregelung 4.2.3 Generalisierter Vergleich der Regelungskonzepte 4.3 Erweiterung auf Mehrmotorenantriebe 4.4 Konzeption und Umsetzung einer Zustandsregelung 4.4.1 Auslegung eines optimalen Zustandsreglers 4.4.2 Rekonstruktion des Zustandsvektors bei Antrieben mit Verzahnungsspiel 4.4.3 Analyse des Gesamtkonzeptes 4.5 Zwischenfazit 5 Verzahnungsspiel in elastischen Antriebssträngen 5.1 Ursachen 5.2 Modellbildung 5.2.1 Klassische Modellierung als Totzone 5.2.2 Erweitertes Spielmodell nach Nordin 5.2.3 Hysterese 5.3 Auswirkungen 5.3.1 Antriebsstrangbelastung 5.3.2 Folgen auf Gesamtsystemebene 5.3.3 Zwischenfazit 5.4 Regelstrategien für spielbehaftete Antriebe 5.4.1 Lineare Eingrößenregelung 5.4.2 Mehrgrößenregelung – Zustandsraummethoden 5.4.3 Umschaltende lineare Regler 5.4.4 Modellprädiktive Regelung 5.4.5 Invertierung der Nichtlinearität 5.4.6 Zwischenfazit 5.5 Konzeption und Umsetzung einer Strategie zum lastminimierten Spieldurchlauf 5.5.1 Optimaltrajektorie zur Spieldurchquerung 5.5.2 Realisierung der Spieldurchquerung 5.5.3 Simulative Verifizierung 6 Zusammenfassung und Ausblick / The present work is motivated by the wide application of slewing drives and yaw drives in a variety of conventional and emerging fields of technology: In wind turbines, yaw drives track the nacelle and rotor according to the current wind direction. In radio telescopes, they enable high-precision azimuthal alignment of the parabolic antenna. And in the construction machinery sector, they are used to rotate the booms of cranes and bucket wheel excavators. At first glance the design of slewing drive systems seems to be simple, but their mechanical dimensioning as well as their reliable operation turn out to be challenging. Measurement data and operating experience show that the drive trains are prone to low-frequency torsional vibrations. In addition, large peak loads occur during reversals of the slewing direction. In this thesis, methods are presented for the modeling, dynamical analysis and control optimization of electromechanical slewing drive systems. Therefore, the mechanical drive train of an exemplary slewing gearbox unit is represented as a detailed multibody system simulation model. A cross-domain modeling approach is pursued in order to capture interactions with the surrounding flexible structures, the drive control and the operating loads as well. The resulting overall mechatronic system model is validated by measurement. The development of accurate system models enables a model-based multivariable control method (LQG) to be designed and tested by simulation. Compared to conventional proportional integral (PI) drive control, this promises active damping of drive train vibrations while simultaneously increasing the operating speed. To estimate the optimization potential for arbitrary elastic drive systems, a systematic comparison of both control strategies is performed. Subsequently, a practical procedure for designing the control system is presented. In addition to robustness, special focus is placed on the limited number of available sensors in industrial drives. Furthermore, the considerable gear backlash is also accounted for as a significant nonlinearity of the controlled system. To reduce peak loads during the reversal of the rotational direction, a novel approach for time- and load-optimized traversing of the gearbox backlash is developed. Since the conventional speed control algorithm is only extended by an additional module, the method is particularly suitable for retrofitting existing drives.:1 Einleitung 1.1 Motivation 1.2 Konkretisierte Problemstellung 1.3 Aufbau der Arbeit 2 Grundlagen und Forschungsstand 2.1 Modellbildung und Simulation von Antriebssystemen 2.1.1 Mehrkörpersystem-Simulation von Antriebssystemen 2.1.2 Modellbildung von Schwenkwerken 2.2 Anwendungsbereiche von Schwenkantrieben 2.2.1 Turmdrehkrane 2.2.2 Windenergieanlagen 2.2.3 Radioteleskope 2.2.4 Baumaschinen 2.3 Untersuchtes Beispielschwenkwerk 2.3.1 Antriebstechnik 2.3.2 Bisherige Untersuchungen an Schaufelradbaggern 3 Modellbildung und Simulation von Schwenkwerken 3.1 Mechanische Komponenten 3.1.1 Schwenkantriebe 3.1.2 Elastische Tragstrukturen am Getriebeausgang 3.1.3 Weitere Antriebsstränge des Gesamtsystems 3.2 Elektrische und informationsverarbeitende Domäne 3.2.1 Aktorik – Elektrische Antriebsmaschine 3.2.2 Informationsverarbeitung – Antriebsregelung 3.2.3 Informationserfassung – Winkelmesssysteme 3.3 Betriebslasten 3.3.1 Quasistatische Lasten 3.3.2 Simulation der bodenmechanischen Interaktion bei Schaufelradbaggern 3.4 Messdatengestützte Validierung der Systemmodelle 3.4.1 Beschreibung des Messaufbaus 3.4.2 Betriebsschwingungsanalyse 3.4.3 Validierung Schwenkwerk – Reversiervorgang 3.4.4 Validierung Gesamtsystem – Grab-Schwenk-Prozess 3.5 Ableitung eines mechanischen Minimalmodells 3.6 Zwischenfazit 4 Drehzahlregelung elastischer Antriebssysteme 4.1 Allgemeine Grundlagen 4.1.1 Führungs- und Störungsverhalten 4.1.2 Stabilität und Performanz 4.1.3 Singulärwertzerlegung von Frequenzgangmatrizen 4.2 Motor mit elastisch gekoppeltem Abtrieb 4.2.1 Proportional-Integrale Eingrößenregelung 4.2.2 Zustandsregelung 4.2.3 Generalisierter Vergleich der Regelungskonzepte 4.3 Erweiterung auf Mehrmotorenantriebe 4.4 Konzeption und Umsetzung einer Zustandsregelung 4.4.1 Auslegung eines optimalen Zustandsreglers 4.4.2 Rekonstruktion des Zustandsvektors bei Antrieben mit Verzahnungsspiel 4.4.3 Analyse des Gesamtkonzeptes 4.5 Zwischenfazit 5 Verzahnungsspiel in elastischen Antriebssträngen 5.1 Ursachen 5.2 Modellbildung 5.2.1 Klassische Modellierung als Totzone 5.2.2 Erweitertes Spielmodell nach Nordin 5.2.3 Hysterese 5.3 Auswirkungen 5.3.1 Antriebsstrangbelastung 5.3.2 Folgen auf Gesamtsystemebene 5.3.3 Zwischenfazit 5.4 Regelstrategien für spielbehaftete Antriebe 5.4.1 Lineare Eingrößenregelung 5.4.2 Mehrgrößenregelung – Zustandsraummethoden 5.4.3 Umschaltende lineare Regler 5.4.4 Modellprädiktive Regelung 5.4.5 Invertierung der Nichtlinearität 5.4.6 Zwischenfazit 5.5 Konzeption und Umsetzung einer Strategie zum lastminimierten Spieldurchlauf 5.5.1 Optimaltrajektorie zur Spieldurchquerung 5.5.2 Realisierung der Spieldurchquerung 5.5.3 Simulative Verifizierung 6 Zusammenfassung und Ausblick

In this paper, three different system topologies for a high performance electric vehicle drive are compared to each other. Next to the classical three phase permanent magnet synchronous machine in different connection schemes, also one topology containing a six phase machine has been included into the study. Suitable inverter topologies are discussed as well as the design of the multiphase winding of the six phase machine. For each of the topologies under investigation, identical types of power semiconductor devices available on the market have been defined as well as an identical active volume of the inverter. The three system topologies (three phase single star machine with parallel inverters, three phase machine in H-bridge / six leg connection, six phase double star machine) have been compared to each other regarding their performance as well as their active short circuit and no-load characteristics. It has been shown by means of simulation that the six phase PSM structure offers some remarkable advantages with regard to its three phase counterparts which makes it adequate for high performance electric vehicle drive applications.:I. Introduction II. Inverter Topologies II.a) Three Phase, Single Star with Parallel Inverter (m3) II.b) Three Phase, H-bridge (m3h) II.c) Six Phase, Double Star (m6) III. Design of Electrical Machine IV. Simulation Results IV.a) Peak Performance IV.b) Induced Back-e.m.f. IV.c) Stationary Short Circuit Condition V. System Comparison VI. Conclusion

This thesis is about the development and performance enhancement of an induction motor electric vehicle drive system. The fundamental operation of the induction motor drive hardware and control software are introduced, and the different modulation techniques tested are described. A software simulation package is developed to assist in the control design and analysis of the drive system. Next, to establish the efficiency gains obtained by using space vector modulation in the improved drive system, an inverter with hysteresis current control is compared to the same inverter with space vector modulation in steady state and on separate driving profiles. A method for determining induction motor harmonic losses is introduced and is based on obtaining the phase current harmonics from sampled induction motor stator phase currents obtained. Using a semi-empirical loss model, the induction motor losses are compared between different pulse width modulation control strategies throughout the torque versus speed operating region. Next, several issues related to the robustness of the control design are addressed. To obtain good performance in the actual vehicle, a new method for driveline resonance compensation is developed and proven to work well through simulation and experiment. Lastly, this thesis discusses the development of a new method to compensate for the gain and phase error obtained in the feedback of the d-axis and q-axis stator flux linkages. Improved accuracy of the measured stator flux linkages will be shown to improve the field oriented controller by obtaining a more accurate measurement of the feedback electromagnetic torque. / Master of Science

An ever-expanding global industry focuses attention on energy supply and use. Cost-effective electrical energy production and reduced consumption pave the way for this expansion. Eskom’s demand-side management (DSM) initiative provides the opportunity for reduced electricity consumption with cost-effective implementation for their respective clients. South African gold mines have to extend their operations to up to 4000 m below the surface to maintain profitable operations. Deep-level mining therefore requires large and energy-intensive cooling installations to provide safe working conditions. These installations generally consist of industrial chillers, cooling towers, bulk air coolers and water transport systems. All of these components operate in unison to provide chilled service water and cooled ventilation air underground. In this study the improved energy efficiency and control of a South African gold mine’s cooling plant is investigated. The plant is separated into a primary and secondary cooling load, resulting in a cascading cooling system. Necessary research was conducted to determine the optimal solution to improve the plant’s performance and electrical energy usage. Variable speed drives (VSD) were installed on the chiller evaporator and condenser water pumps to provide variable flow control of the water through the chillers, resulting in reduced motor electricity usage. Potential electricity savings were simulated. Proposed savings were estimated at 600 kW (13.6%) daily, with an expected saving of R 2 275 000 yearly, resulting in a payback period of less than 9 months. Results indicated are based on total savings, as VSD savings and control savings were combined. The VSDs that were installed, were controlled according to an optimum simulation model’s philosophy. A real-time energy management program was used to control the VSDs and monitor the respective systems. The program’s remote capabilities allow for off-site monitoring and control adjustments. A control strategy, which was implemented using the management program, is discussed. Energy efficiency was achieved through the respective installations and control improvements. The results were analysed over an assessment period of three months to determine the viability of the intervention. A newly installed Bulk Air Cooler (BAC) added to the service delivery of the cooling plant post installation of the VSDs. Focusing on service delivery to underground showed a savings of 1.7 MW (33.6%) daily and a payback period of 3.6 months (0.3 years). The overall implementation showed an average energy saving of 2.3 MW (47.1%) daily, with the result that a daily saving of R 23 988.20 was experienced, reducing the payback period to 2.3 months (0.2 years). Through the installation of energy-efficiency technology and a suitable control philosophy, a cost-effective, energy-efficiency improvement was created on the case-study cooling plant. / MIng (Mechanical Engineering), North-West University, Potchefstroom Campus, 2014

An ever-expanding global industry focuses attention on energy supply and use. Cost-effective electrical energy production and reduced consumption pave the way for this expansion. Eskom’s demand-side management (DSM) initiative provides the opportunity for reduced electricity consumption with cost-effective implementation for their respective clients. South African gold mines have to extend their operations to up to 4000 m below the surface to maintain profitable operations. Deep-level mining therefore requires large and energy-intensive cooling installations to provide safe working conditions. These installations generally consist of industrial chillers, cooling towers, bulk air coolers and water transport systems. All of these components operate in unison to provide chilled service water and cooled ventilation air underground. In this study the improved energy efficiency and control of a South African gold mine’s cooling plant is investigated. The plant is separated into a primary and secondary cooling load, resulting in a cascading cooling system. Necessary research was conducted to determine the optimal solution to improve the plant’s performance and electrical energy usage. Variable speed drives (VSD) were installed on the chiller evaporator and condenser water pumps to provide variable flow control of the water through the chillers, resulting in reduced motor electricity usage. Potential electricity savings were simulated. Proposed savings were estimated at 600 kW (13.6%) daily, with an expected saving of R 2 275 000 yearly, resulting in a payback period of less than 9 months. Results indicated are based on total savings, as VSD savings and control savings were combined. The VSDs that were installed, were controlled according to an optimum simulation model’s philosophy. A real-time energy management program was used to control the VSDs and monitor the respective systems. The program’s remote capabilities allow for off-site monitoring and control adjustments. A control strategy, which was implemented using the management program, is discussed. Energy efficiency was achieved through the respective installations and control improvements. The results were analysed over an assessment period of three months to determine the viability of the intervention. A newly installed Bulk Air Cooler (BAC) added to the service delivery of the cooling plant post installation of the VSDs. Focusing on service delivery to underground showed a savings of 1.7 MW (33.6%) daily and a payback period of 3.6 months (0.3 years). The overall implementation showed an average energy saving of 2.3 MW (47.1%) daily, with the result that a daily saving of R 23 988.20 was experienced, reducing the payback period to 2.3 months (0.2 years). Through the installation of energy-efficiency technology and a suitable control philosophy, a cost-effective, energy-efficiency improvement was created on the case-study cooling plant. / MIng (Mechanical Engineering), North-West University, Potchefstroom Campus, 2014

The thesis is performed in order to improve the curvic coupled engagement of a dog clutch situated in the transfer case of a truck. The dog clutch is used to engage the so called all-wheel-drive system of the truck. If the driver tries to engage the all-wheel-drive when truck’s rear wheels already skid, due to a slippery surface a relative rotational speed in the dog clutch will occur. This relative rotational speed will cause the dog clutch to bounce back of itself before engagement, or to not engage at all. The dog clutch has been redesigned to prevent this. Dynamic simulations using MD Adams have been made for the existing model, for the models created in previous works, and for the new model in order to figure out which of them will show the most stable engagement, at high relative rotational speed. The implemented simulations show that better results can be obtained. Separation into two parts of the disc pushed by the fork, shows that dog clutch’s engagement is faster and more stable, comparing to the original model and the other created models. The new model shows better coupling in the whole range of the relative rotational speed from 50 up to 120rpm.

Det här examensarbetet skildrar en konceptstudie och kostnadsuppskattning av enuniversell testrigg för växellådor. Arbetet har genomförts på uppdrag av SwepartTransmission AB och har resulterat i koncept- och komponentförslag samtkostnadsuppskattning av ett universellt test system av växellådor. / This degree project cover a concept study and cost analyses of a universal test rig forgears. The project has been performed for Swepart Transmission AB and has resultedin a concept and component suggestion as well as cost analysis of a universal testsystem for gears.

Main purpose of the paper is to present high-response hydraulic linear drive, which is controlled with new digital piezo valve and where the new position transducer is integrated as a part of hydraulic cylinder. Hydraulic digital piezo valve with main static and dynamic characteristics as well as its functionality is presented in detail. The main static and dynamic characteristics of dygital piezo valve which influence directly on the linear drive performance are high resolution of the volume flow rate and high resposne of the valve. Beside valve characteristics the new integrated position transducer, the digital controller and control method, presented in the paper, have major impact on linear drive preformance. At the end of the paper the step response and position resolution of the hydraulic linear drive controlled with the new digital valve is compared with the results of reference hydraulic drive controlled with high response proportional valve.

The drive train components and the machine control system significantly influence the fuel consumption of mobile machinery. The demonstrator vehicle “Green Wheel Loader” developed within the joint research project “TEAM” combines the most promising drive concepts currently available for mobile machines with an innovative operating strategy. The developed drive and control system proved its functionality and performance under realistic operation conditions in a gravel pit. Reference test showed 10 – 15 % fuel savings of the prototype vehicle compared to a state-of-the-art series machine.