| 1. |
- Falk Olson, Gustaf, 1992-, et al.
(författare)
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Enabling Variable Phase-Pole Drives with the Harmonic Plane Decomposition
- 2024
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Ingår i: IEEE Access. - : Institute of Electrical and Electronics Engineers (IEEE). - 2169-3536. ; 12, s. 40049-40063
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Tidskriftsartikel (refereegranskat)abstract
- Magnet-free variable phase-pole machines are competitive alternatives in electric vehicles where torque-speed operating region, reliability, cost, and energy efficiency are key metrics. However, their modeling and control have so far relied on existing fixed-phase and pole-symmetrical models, limiting their drive capabilities especially when switching the number of poles on the fly. This paper establishes the harmonic plane decomposition theory as a space-discrete Fourier transformation interpretation of the Clarke transformation, decomposing all pole-pair fields into a fixed number of orthogonal subspaces with invariant parameters. The model remains unaltered for all phase-pole configurations, guaranteeing continuity even under phase-pole transitions. Relations of the state and input space vectors, and model parameters to those of the vector space decomposition theory used for multiphase machines are established via the use of the complex winding factor. Experiments confirm the modeling theory and demonstrate its practical usefulness by performing a field-oriented-controlled phase-pole transition. Non-trivial configurations with more than one slot/pole/phase and a fractional phase number are also demonstrated.
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| 2. |
- Haq, Omer Ikram ul, et al.
(författare)
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Generalized Harmonic Injection Strategy for Multiphase Induction Machine Control
- 2024
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Ingår i: IEEE transactions on energy conversion. - : Institute of Electrical and Electronics Engineers (IEEE). - 0885-8969 .- 1558-0059. ; 39:2, s. 1245-1254
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Tidskriftsartikel (refereegranskat)abstract
- A multiphase induction machine model using vector space decomposition provides insights into many space harmonics through decoupled reference frames. These decoupled reference frames host specific space vectors related to particular space harmonics. Based on the physical winding configuration, these vector spaces can be excited independently and simultaneously for the production of torque. However, this approach may result in beat oscillations due to interference between excited vector spaces if proper synchronization of vector spaces is not maintained. This paper describes this phenomenon through experimental tests. Furthermore, a solution eliminating the beat oscillations is proposed while optimizing the stator current or rotor flux linkage peaks. The effectiveness of the solution is experimentally verified on a 9-phase induction machine.
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| 3. |
- Ikram Ul Haq, Omer, et al.
(författare)
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Estimation of Equivalent Circuit Parameters of Multiphase Induction Machines by Exploitation of Space Harmonic Relations
- 2023
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Ingår i: 2023 IEEE International Electric Machines & Drives Conference (IEMDC). - : IEEE.
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Konferensbidrag (refereegranskat)abstract
- A multiphase induction machine model using vector space decomposition or harmonic plane decomposition provides insights into many space harmonics through decoupled reference frames, each hosting specific space vectors related to particular harmonics. The dynamics of each voltage and current space vector are described by an equivalent circuit, whose parameters must be obtained either by finite-element analysis or laboratory measurements. This paper presents and experimentally verifies a methodology for calculating these parameters from a single configuration, with minimal knowledge of the geometrical dimensions of the machine.
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| 4. |
- Ikram ul Haq, Omer, et al.
(författare)
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Method of controlling an electrical machine
- 2018
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Patent (populärvet., debatt m.m.)abstract
- A method of controlling an electrical machine, wherein the method includes: a) injecting a first voltage waveform (uhx) with a first fundamental frequency into the electrical machine in a first axis of a rotor reference frame, combined with a voltage signal for controlling the electrical machine, b) determining a second axis current component (iqhx) of a second axis of the rotor reference frame, having the first fundamental frequency, generated in response to the injection of the first voltage waveform (uhx), c) controlling based on the second axis current component (iqhx) a second axis voltage component (uqhx) of the second axis, having the first fundamental frequency, to obtain an adjusted second axis voltage component for controlling the second axis current component (iqhx) towards zero, d) feeding back the adjusted second axis voltage component to combine the adjusted second axis voltage component with the voltage signal and the injected first voltage waveform (uhx), and repeating steps b)-d) until the second axis current component is smaller than a threshold value (iqhx), e) determining a differential cross-coupling parameter of the electrical machine based on the second axis voltage component (uqhx) and a first axis current component (idhx) having the first fundamental frequency, when the second axis current component is smaller than the threshold value (iqhx), and g) controlling the electrical machine based on the differential cross-coupling parameter.
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| 5. |
- Ikram Ul Haq, Omer, et al.
(författare)
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Online Winding Reconfiguration of a Multiphase Stator
- 2023
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Ingår i: 2023 IEEE 14th International Conference on Power Electronics and Drive Systems (PEDS). - : Institute of Electrical and Electronics Engineers (IEEE). ; , s. 07-10
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Konferensbidrag (refereegranskat)abstract
- A multiphase machine control implementing vector space decomposition or harmonic plane decomposition for modeling purposes can reconfigure the stator's current distribution to generate magnetomotive force waves with different pole pair numbers simultaneously. The pole pair numbers are an integer multiple of the pole pairs generated by the physical winding configuration. This property can be used for reconfiguring the pole-pair number in real time or increasing the system's torque density. This paper studies the modeling and the impact of symmetrical and asymmetrical winding configurations on the pole-pair number reconfiguration. Furthermore, pole number transition is experimentally verified on a proposed winding configuration.
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| 6. |
- Ikram ul Haq, Omer, et al.
(författare)
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Robust automatic segregation of harmonics in electric drives by means of the Mahalanobis distance
- 2017
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Ingår i: 2017 IEEE International Electric Machines and Drives Conference (IEMDC). ; , s. 1-8
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Konferensbidrag (refereegranskat)abstract
- This paper discusses the use of the Mahalanobis distance as a solution for a robust and automatic segregation of harmonics in the signals measured in electric drives, as for example the phase currents or the mechanical speed. The Mahalanobis distance is used during real-time operation to clean the results of an on-line frequency analysis, reducing the uncertainties related to frequency resolution, spectral leakage and background noise. At the same time, it is a powerful tool to classify the known harmonics from the unknown ones, thus providing the drive with valuable information that can be used for further decisional control actions. The overall theoretical background is reviewed as well as its implementation in an operational drive system. Experimental results are provided, proving the validity of the concept.
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| 7. |
- Kanchan, Rahul, et al.
(författare)
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Comparative assessment of voltage modulation methods for asymmetric six-phase machines
- 2020
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Ingår i: 2020 22nd European Conference on Power Electronics and Applications, EPE 2020 ECCE Europe. - : Institute of Electrical and Electronics Engineers (IEEE).
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Konferensbidrag (refereegranskat)abstract
- In the most common industrial adaptation of electric drives for asymmetric six-phase machines, two independent three-phase converter units are configured to supply two three-phase winding sets. In principle, the converter units may use their own internal clock, acting independently on the two sets of windings with both the voltage pulse-width modulation and the sampling of phase currents. In this case, the machine is controlled with a vector space decomposition approach, this may cause some synchronization issues with voltage references and current sampling.In this paper, an asymmetric six-phase permanent-magnet machine is controlled with a vector space decomposition architecture has been controlled with individual current controllers in each harmonic plane. The output voltage references from the current controllers is fed to pulse-width modulators. The modulators are selected among the most promising methods for two-level converter-fed six-phase machines from the literature. A comparative analysis is performed through simulation studies, with the objective of comparing the performance of various modulators considering synchronization of voltage reference signals and phase current sampling.
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| 8. |
- Peretti, Luca, et al.
(författare)
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Method and controller for determining an undesired condition in an electrical drive system
- 2016
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Patent (populärvet., debatt m.m.)abstract
- A method for determining an undesired condition in an electrical drive system including an electrical machine and an electrical drive, wherein the method includes a) obtaining a measured signal of an electrical or mechanical parameter, b) obtaining a frequency spectrum of the measured signal, that contains a measured frequency component, c) determining whether the measured frequency component is within a predetermined distance from a trend line, which trend line is associated with only one specific frequency component of the electrical or mechanical parameter present during a specific undesired condition, d) on the condition that the measured frequency component is within the predetermined distance from the trend line increasing a counter associated with the trend line, e) repeating steps a) to d), wherein in case the counter reaches a predetermined number determining that the electrical drive system is subjected to the undesired condition associated with the trend line.
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