A holistic DC link architecture design method for multiphase Integrated Modular Motor Drives

This article describes a holistic DC link architecture design method that considers the end-application of the drive and its corresponding constraints e.g. the maximum battery ripple current for a battery-supplied inverter. Also, the levers that are available to comply with the design criteria are presented e.g. the use of interleaved carrier waves. This holistic approach will result in a feasible and performant Integrated Modular Motor Drive from an application point of view. Finally, a platform is presented that was developed for feasibility and performance assessment of various DC link architectures obtained from the holistic design approach. The platform comprises a fifteen phase integrable modular motor drive for an Axial Flux Permanent Magnet Synchronous Machine. It allows non-intrusive reconfiguration of the DC link architecture and implementation of various control strategies and interleaved PWM schemes

Predictive control of an axial flux permanent magnet synchronous machine

This paper examines the (dis)advantages of predictive control for the torque regulation of an axial flux permanent magnet synchronous machine fed by a two-level voltage source inverter. Three different types of predictive controllers are studied: finite-set model based predictive control, deadbeat control and finite-set model based predictive control with duty cycle calculation. A standard PI controller is added to provide a benchmark. The real-life performance of the control algorithms is tested on a 4 kW laboratory drive setup. It is concluded that the PI controller shows superior steady-state behavior, whereas the predictive controllers excel when it comes to dynamic performance

Performance degradation of surface PMSMs with demagnetization defect under predictive current control

To control the current of a surface mounted permanent magnet synchronous machine fed by a two-level voltage source inverter, a large variety of control algorithms exists. Each of these controllers performs differently concerning dynamic performance and control- and voltage quality, but also concerning sensitivity to demagnetization faults. Therefore, this paper investigates the performance degradation of three advanced predictive controllers under a partial demagnetization fault. The three predictive controllers are: finite-set model based predictive control, deadbeat control, and a combination of both previous algorithms. To achieve this goal, the three predictive controllers are first compared under healthy conditions, and afterwards under a partial demagnetization fault. A PI controller is added to the comparison in order to provide a model-independent benchmark. Key performance indicators, obtained from both simulations and experimental results on a 4 kW axial flux permanent magnet synchronous machine with yokeless and segmented armature topology, are introduced to enable a quantification of the performance degradation of the controllers under a demagnetization fault. A general conclusion is that the deadbeat controller shows superior control quality, even under partial demagnetization

Simultaneous DC-link and stator current ripple reduction with interleaved carriers in multiphase controlled integrated modular motor drives

To meet the demand for increasingly high power density in electric drives, the concept of a so-called integrated modular motor drive has emerged. The machine is composed of multiple identical modules, which receive individual control signals for multiphase control, to reduce unwanted stator current harmonics. Each module is equipped with its own power electronic converter, which is integrated in the machine housing. This integration imposes strict constraints on the DC-link capacitor design. To reduce the DC-link current ripple, and hence relax the design constraints on the DC-link capacitor, without compromising the possibility to eliminate unwanted stator current harmonics by means of multiphase control, a new interleaving strategy is proposed in this paper. The n modules of the machine are split into p subgroups of m modules for interleaving, while the n-phase control is preserved. An analytical model, simulations and experimental results are provided for a 4 kW test setup, confirming that multiphase control can be combined with interleaving. As a result, both the stator current harmonic distortion and the DC-link current ripple can be reduced simultaneously

Distributed control strategies for modular permanent magnet synchronous machines taking into account mutual inductances

To meet the need for flexibility and reliability in present-day motor drive applications, each phase in a permanent magnet synchronous machine is considered as a separate module in this paper, with its own dedicated controller. To utilize the full potential of these modular drives, decentralized and distributed control is applied. One of the main challenges of these control strategies is that the local current controllers only have local information at their disposal, which leads to reduced performance in comparison with a centralized control strategy. The mutual inductances in permanent magnet synchronous machines cause a coupling between the different phases, but a decentralized or distributed control strategy does not have a complete overview of all the phase voltages and currents. Therefore, it is studied in this paper how much the mutual inductances affect the performance of decentralized and distributed deadbeat control strategies in the abc-reference frame. Furthermore, a new distributed control strategy is proposed. By making intelligent use of communication between the phases, and the sinusoidal waveform of the phase currents and voltages, this distributed control strategy reaches a similar level of performance as a centralized control strategy

Multi-agent position estimation in modular motor drives using low-resolution sensors

Because a modular motor drive is composed of multiple identical pole drive units and controllers, it can be considered as a multi-agent system. This makes modular motor drives particularly interesting during faults, when the remaining healthy agents assure the continuity of operation. Nevertheless, for some crucial information such as the rotor position, these drives still rely on a single sensor which introduces a single point of failure. In this work, this single high-resolution position sensor is replaced by multiple binary, low-resolution position sensors. A vector tracking observer algorithm, implemented in the different controllers, processes this low-resolution sensor data into a position estimate. Subsequently, these position estimates of the different agents are exchanged with other agents using a distributed averaging algorithm. For this latter approach, it is shown in this work that it improves the position estimation under healthy conditions as well as during agent malfunctions. The concept is demonstrated on a modular axial-flux PMSM with fifteen pole drive units, each equipped with a low-resolution position sensor, that are assigned to five agents

Voorspellende controle van een permanentemagneetbekrachtigde machine met axiale flux

Voor de koppelregeling van een permanentemagneetbekrachtigde machine met axiale flux bestaat een uitgebreid aanbod aan controlealgoritmes. Niet elk algoritme is echter even eenvoudig, doeltreffend of efficiënt. Daarom worden in dit artikel drie verschillende voorspellende regelaars vergeleken met elkaar en met een standaard PI-regelaar. De drie onderzochte voorspellende regelaars zijn finite-set model based predictive control, deadbeat control en finite-set model based predictive control met duty cycle berekening. De vergelijkende studie gebeurt eerst in simulatie. Daarna volgt een experimentele verificatie op een prototype van de machine. De belangrijkste conclusies zijn dat de PI-regelaar uitblinkt in eenvoud en kwaliteit van de koppelcontrole in steady-state: enkel de deadbeat-regelaar vertoont een vergelijkbaar lage koppelrimpel. De voorspellende regelaars leveren betere dynamische prestaties