The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
This paper considers the electromagnetic and structural co-design of synchronous reluctance (SyR) machines for high-speed applications, with the aid of optimization algorithms. The aim of this work is twofold. First, three commercial electrical steel grades are compared to establish quantitatively how steel properties influence the performance of high-speed SyR machines. The considered steel grades...
The emergence of high-frequency converters has introduced additional stress on the bearings of the systems they are used in: the high-frequency components of the converter output voltage may lead to building up of voltage across the bearings. If it exceeds the voltage that the bearing can withstand these voltages may cause a discharge leading to so-called “discharge bearing currents”. This paper studies...
During the mass production of surface-mounted permanent magnet motors the rotor and stator geometrical dimensions usually deviate from their nominal values due to manufacturing tolerances which impact machine performance. Radial misalignment in the placement of the permanent magnets on the rotor surface as well as slot opening variations are common deviations observables in the final product. As a...
Switched reluctance motors (SRMs) are popular due to their advantages of simple and robust construction, wide speed range, and fault tolerance. Commonly cited limitations of SRMs are acoustic noise and the need for a different inverter configuration. It has been reported that when the SRM phases are excited with sinusoidal bipolar currents, there is significant reduction in acoustic noise. Further,...
A switched reluctance machine (SRM) is applicable to high speed applications due to its simple magnetic structure and mechanical robustness. During the operation of a converter, however, it causes high peak phase current which leads to a rise in the VA rating of an SRM system. Therefore, this paper investigates the reduction of peak phase current and describes the basic design procedure of an SRM...
This paper proposes a non-linear observer for Induction Machine (IM) drives which takes into consideration the saturation effects. The non-linear observer is based on an original formulation of the dynamic model of the IM taking into consideration the magnetic saturation of the iron core. A Lyapunov based convergence analysis is proposed in order to suitably compute the observer gain guaranteeing...
A block commutation based position sensorless method for low speed regions has some advantages [6]-[11]. This method introduces "Induced Voltage caused by Magnetic Saturation (IVMS)". The IVMS based method can be applied to most permanent magnet synchronous motors (PMSM) with or without a saliency rotor structure. However, some motors that have a closed-slot stator structure cannot easily...
This paper investigates the calculation, modelling and interpretation of efficiency maps for electrical machines. The efficiency maps are calculated using a finite-element based mapping of losses, torque and flux-linkage as a function of the d- and q-axis currents and speed. For modelling efficiency maps, it is shown that a number of key loss types can be described in the form Tmωn. The effect of...
For critical load supplied with dual power source, solid state transfer switch (SSTS) is usually employed to realize rapid bus transfer. A SSTS-based soft transfer control method is proposed in this paper to suppress the inrush current when the load driven by motor is switched onto alternate source. The research focus on concrete soft transfer control strategy and how to recalculate firing angles...
This study is used to highlight the potentials of flux switching PM machines for medium-speed wind generator drives, considering among other things, that the rotor pole number is critical to the electromagnetic torque output. The initial result obtained by finite-element simulations and theoretical analyses of the pre-optimised 12/10 FSPM topology compared to its 12/14 counterpart show that with higher...
This paper presents a Switched Reluctance Motor (SRM) capable of running up to 50,000rpm whilst producing an output power of 60kW. The high speed operation allows for a smaller overall size, which in turn leads to lower manufacturing costs. It is demonstrated that, at very high speeds, merely shrinking the motor is not enough and certain mechanical considerations should be taken into account. A rotor...
Single phase IMs have been widely used in home appliances such as fans, pumps and so on because they are directly driven by commercial AC power supply. However, the motor efficiency is very low because the rotor winding and auxiliary winding generate large copper loss. Therefore, in this research, a novel single phase switched reluctance motor (SRM) which is directly driven by commercial AC power...
The injection of a high frequency signal in the stator via inverter has been proven to be a viable option to estimate the magnet temperature in permanent magnet synchronous machines (PMSMs). Injection of a pulsating d-axis current is especially appealing, as it is insensitive to the speed, Ld and Lq inductance variations. Furthermore, it is suitable both for interior PMSMs (IPMSMs) and surface PMSMs...
A computationally efficient method is presented to investigate additional cogging torque harmonics resulting from misalignment of the rotor and stator caused by assembly and manufacturing tolerances in an axial flux, fractional pitch PMSM. The hybrid analytical / FEA method utilizes superposition of a pole transition over a single stator slot and is used to predict the effect on cogging torque of...
This paper presents a simple approach to account for saturation and its effects, based on varying effective air-gap length of an analytical model of surface-mounted permanent-magnet (PM) synchronous motor (SMPMSM). Firstly, the real structure of the machine is modeled with two concentric regions and the magnetic potential vectors are analytically calculated by solving the Maxwell's equations. Then,...
Permanent-magnet synchronous machines (PMSMs) are considered a very promising machine type for high-speed applications nowadays. As permanent-magnet (PM) materials are generally fragile, a high strength sleeve is required to protect the PMs from damage due to extreme centrifugal forces. The rotor sleeve occupies space of the effective air gap of the PMSMs, so it is difficult to perform the electromagnetic...
This paper presents a input-output Feedback Linearization (FL) control technique for rotating Induction Motors (IM), which takes into consideration the magnetic saturation of the iron core. Starting from a new formulation of the IM dynamic model, taking into consideration the magnetic saturation, expressed in a space-state form in the rotor flux oriented reference frame, the corresponding FL technique...
Portable AC generators directly driving isolated AC loads require tight voltage regulation, good voltage waveform quality and high efficiency. This paper compares the performance of a 4-pole, 16 kW, three-phase interior permanent-magnet generator with a single-phase resistive load when operating with both star and delta winding connections. The results of analytical and finite-element simulations...
The performance of a cage-less 16-kW, 1,500-rpm interior permanent magnet machine developed for a portable generator application is examined when run as a motor under open-loop volts-per-hertz control from an inverter. The analytical and experimental steady-state results show the machine can operate with high power-factor and efficiency. The dynamic results show robust operation in starting and the...
The use of interior permanent magnet synchronous motors (IPMSMs) with rare-earth magnets has recently been on the rise. When IPMSMs are operated to expand the operating speed range by flux-weakening control, irreversible demagnetization might occur in the magnets in the rotor and deteriorate motor characteristics. To prevent this, dysprosium (Dy) is added to rare-earth magnets. However, it is desirable...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.