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-Stator winding topologies (a) additional DC winding, (b) double-star winding with DC injection, (c) converter controlled 3-phase winding, (d) 3-phase winding with tuned reactive loading
Source publication
The wound field synchronous machine has widespread use both as a motor and a generator, due to its low cost, wide power range and its consolidated history built over decades of operation. A critical aspect of these machines is the method of excitation to the field winding. Typically, the choice is between a static excitation system using slip-rings...
Contexts in source publication
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... the aim of removing the 'separate' exciter through modifications on the stator can be typically achieved by having a stator winding design that can induce an excitation current in the rotor winding. The most common method demonstrated in literature is to add an additional DC winding to the stator [21], [26], as shown in Fig. 3a. This leaves the design of the phase winding flexible with both three-phase and single-phase options demonstrated. An alternative arrangement is proposed in [11], [31] where a double star phase winding is used with DC injected between the star-points, as observed in Fig. 3b. An AC excitation method can be achieved, typically by ...
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... is to add an additional DC winding to the stator [21], [26], as shown in Fig. 3a. This leaves the design of the phase winding flexible with both three-phase and single-phase options demonstrated. An alternative arrangement is proposed in [11], [31] where a double star phase winding is used with DC injected between the star-points, as observed in Fig. 3b. An AC excitation method can be achieved, typically by leveraging harmonics in the machine to induce an excitation current. These can be provided by a connected converter (Fig. 3c) [12], [14] or through the layout of the armature winding with a reactive load (Fig. 3d) [7], [13]. A key benefit of harmonic excitation is that the machine ...
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... demonstrated. An alternative arrangement is proposed in [11], [31] where a double star phase winding is used with DC injected between the star-points, as observed in Fig. 3b. An AC excitation method can be achieved, typically by leveraging harmonics in the machine to induce an excitation current. These can be provided by a connected converter (Fig. 3c) [12], [14] or through the layout of the armature winding with a reactive load (Fig. 3d) [7], [13]. A key benefit of harmonic excitation is that the machine can be designed to self-regulate its output, but careful choice of pole combinations for the excitation and MG magnetic circuits are required to ensure mechanical stability ...
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... phase winding is used with DC injected between the star-points, as observed in Fig. 3b. An AC excitation method can be achieved, typically by leveraging harmonics in the machine to induce an excitation current. These can be provided by a connected converter (Fig. 3c) [12], [14] or through the layout of the armature winding with a reactive load (Fig. 3d) [7], [13]. A key benefit of harmonic excitation is that the machine can be designed to self-regulate its output, but careful choice of pole combinations for the excitation and MG magnetic circuits are required to ensure mechanical stability ...
Citations
... Their straightforward design and low rotor inertia result in rapid responsiveness. While challenges [59] like noise, vibrations, and complex electronics have limited their use in electric vehicles, WRSMs are now gaining popularity as a solution to reduce reliance on rare-earth metals and overall costs [61], positioning them as a promising choice for future automotive applications. • SRMs eliminate windings, slip rings, and PMs on the rotor, building the opportunity to eliminate rare-earth metals and reduce the cost. ...
... PMSMs require no rotor winding and thus the physical size of the machine is reduced. Although this reduction in size can save on the total manufacturing costs, rare-earth permanent magnets are costly, and susceptible to large price variations and sourcing constraints [9]. Non-permanent magnet machines, such as wound-field machines, have generally lower overall material costs. ...
Non-overlap winding technology continues to remain relevant in the design of wound-field machines as an alternative for high torque density permanent magnet machines. In this paper, the finite element analyses-optimisation of two variants of the non-overlap wound-field machines viz., wound-field flux switching machine (WF-FSM) and phase shifting wound rotor synchronous machine (WRSM), are compared, first in terms of their performance for large-scale converter-fed wind generator drives, then experimentally as sub-scaled converter-fed versus direct grid-connected wind generators, respectively. This study is unique because there are no prior attempts to design, optimize and analyse on these machines for medium-speed wind power generation, as well as experiment on sub-scale prototypes for direct-grid and converter-fed operation. All investigations are contemplated in the medium-speed wind generator drivetrain which provides a tradeoff for generator efficiency and size. From the global optimisation of both machines at large-scale power levels, the torque per mass of the WF-FSM is found to be 50 % lesser compared to the WRSM. This is due to approximate volume, with closely matched optimal split and aspect ratios. In terms of the sub-scaled experimentation, both generators can easily vary their generated output power to match with varying wind resource, but direct grid-connected WRSM generator yields better efficiency performance compared to the WF-FSM converter-fed operating mode, given that the generator terminal voltage of the former is highly regulated.
... Slip rings are more common on both low power and high power machines where, for low power machines the converter costs are low, and for high power machines the response time benefits of a static excitation system are critical. There has been significant research effort into the design of a brushless ES that combines its magnetic circuit with that of the main machine, allowing for improved power density, reduced manufacturing complexity, and ultimately reduced cost [2]. Of these methods, one of particular interest to the medium power designer is that first presented in [3]. ...
The excitation system (ES) of the wound-field synchronous machine (WFSM) has remained largely unchanged over the past 50 years. Nonetheless, there has been significant research into exciterless solutions, which, through the integration of the ES with the main machine, aim to offer improved power density, simplified manufacture, and better cooling opportunities.
