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When solving the cogging torque of complex electromagnetic structures, such as consequent pole hybrid excitation synchronous (CPHES) machine, traditional methods have a huge computational complexity. The notable feature of CPHES machine is the symmetric range of field-strengthening and field-weakening, but this type of machine is destined to be equipped with a complex electromagnetic structure. The purpose of this paper is to propose a hybrid analysis method to quickly and accurately solve the cogging torque of complex 3D electromagnetic structure, which is applicable to CPHES machine with different magnetic pole shapings.

In this paper, a hybrid method for calculating the cogging torque of CPHES machine is proposed, which considers three commonly used pole shapings. Firstly, through magnetic field analysis, the complex 3D finite element analysis (FEA) is simplified to 2D field computing. Secondly, the discretization method is used to obtain the distribution of permeance and permeance differential along the circumference of the air-gap, taking into account the effect of slots. Finally, the cogging torque of the whole motor is obtained by using the idea of modular calculation and the symmetry of the rotor structure.

This method is applicable to different pole shapings. The experimental results show that the proposed method is consistent with 3D FEA and experimental measured results, and the average calculation time is reduced from 8 h to 4 min.

This paper proposes a new concept for calculating cogging torque, which is a hybrid calculation of dimension reduction and discretization modules. Based on magnetic field analysis, the 3D problem is simplified into a 2D issue, reducing computational complexity. Based on the symmetry of the machine structure, a modeling method for discretized analytical models is proposed to calculate the cogging torque of the machine.

The purpose of this paper is to focus on the machine design and control strategy of the permanent magnet synchronous generator (PMSG) system, especially utilized in variable speed applications, in order to stabilize the output voltage on the dc link over a wide speed range.

Different ac/dc power converter topologies are comparatively studied, each with an accordingly designed PMSG, so as to investigate the influence of the armature winding inductance as well as the relationship between the PMSG and power converter topologies.

Pulse width modulation (PWM) rectifier is preferable for the said application due to its good performance and controllability. Moreover, by employing the PWM rectifier, relatively large inductance of the PMSG is considered for both short-circuit current reduction and field regulation.

Field-regulating control is realized with a space vector PWM (SVPWM) rectifier, which can weaken the PMSG magnetic field during high-speed operation, while even properly enhance the field at low speed, ensuring a small change of the PMSG output voltage and a stable dc voltage.

Aim of the present monograph is the economic analysis of the role of MNEs regarding globalisation and digital economy and in parallel there is a reference and examination of some legal aspects concerning MNEs, cyberspace and e‐commerce as the means of expression of the digital economy. The whole effort of the author is focused on the examination of various aspects of MNEs and their impact upon globalisation and vice versa and how and if we are moving towards a global digital economy.

In order to keep the advantages of PM generators and eliminate its disadvantage – difficulty in regulating the magnetic field, hybrid excitation is an effective way. The purpose of this paper is to propose a novel way to achieve hybrid excitation by use of tooth harmonic field.

Unlike weakening the tooth harmonics field and EMF in traditional machines, in this paper the tooth harmonics field is proposed to form a novel hybrid excitation permanent magnet synchronous generator (HEPMSG).

The generation mechanism of tooth harmonic electromotive force (EMF) of rotor winding is introduced, and its influencing factors are discussed in detail. The matching design of tooth harmonic winding and field winding for maximum output field current of tooth harmonic excitation system is analyzed.

This machine can achieve not only effective adjustment of the air-gap magnetic field, but also elimination of the brushes and slip rings.

Unlike weakening the tooth harmonics field and EMF in traditional machines, in this paper the tooth harmonics filed is proposed to form a novel hybrid excitation PM synchronous generator. This machine can achieve not only effective adjustment of the air-gap magnetic field, but also elimination of the brushes and slip rings.

Discusses the 27 papers in ISEF 1999 Proceedings on the subject of electromagnetisms. States the groups of papers cover such subjects within the discipline as: induction machines; reluctance motors; PM motors; transformers and reactors; and special problems and applications. Debates all of these in great detail and itemizes each with greater in‐depth discussion of the various technical applications and areas. Concludes that the recommendations made should be adhered to.

Nobody concerned with political economy can neglect the history of economic doctrines. Structural changes in the economy and society influence economic thinking and, conversely, innovative thought structures and attitudes have almost always forced economic institutions and modes of behaviour to adjust. We learn from the history of economic doctrines how a particular theory emerged and whether, and in which environment, it could take root. We can see how a school evolves out of a common methodological perception and similar techniques of analysis, and how it has to establish itself. The interaction between unresolved problems on the one hand, and the search for better solutions or explanations on the other, leads to a change in paradigma and to the formation of new lines of reasoning. As long as the real world is subject to progress and change scientific search for explanation must out of necessity continue.

The purpose of this paper is to focus on various control strategies for permanent magnet synchronous generator (PMSG) systems, in order to stabilize the dc link output voltage over a wide operation speed range.

Two control methods, namely, the flux regulation control (FRC) which adjusts the stator flux linkage and then indirectly stabilize the dc link voltage, and the direct voltage control (DVC) which directly stabilize the dc link voltage by regulating the power angle, are proposed in this paper. Both methods can be realized by either approach of the conventional space vector pulse width modulation (SVPWM) or the proposed single voltage vector modulation (SVVM).

The FRC can optimize the field in the PMSG, however, the realization is complicated. The DVC need not estimate and regulate the stator flux linkage, hence is easy to implement. On the other hand, the SVPWM can provide smooth armature current and dc link voltage, while the SVVM applies only one voltage vector during each control cycle, hence, is simple to realize and requires the minimum switching on the PWM rectifier. All cross-combinations between the two control methods and the two realization approaches work well.

The proposed FRC and DVC methods are simpler than the conventional field oriented control, while the proposed SVVM is a novel and efficient approach to generate the PWM status. Optimal cross-combination, either of SVPWM-FRC, SVVM-FRC, SVPWM-DVC and SVVM-DVC, can be chosen to satisfy the system characters and requirements.

The present study aims to seek the strategic analysis of the entrepreneurship of agricultural colleges (AC).

In terms of approach, this research was a combination of exploratory and hybrid methods. The present study was conducted in four stages. In the first stage, an open-ended questionnaire was designed to identify the strengths, weaknesses, opportunities and threats of entrepreneurship in AC (qualitative method). In the second stage, the Delphi-Fuzzy questionnaire was designed based on the results obtained from the first stage. In the third stage, the criteria of strengths, weaknesses, opportunities and threats of entrepreneurship of AC were analyzed based on the pairwise comparison (quantitative method) by the sample using a fuzzy hierarchical analysis process (FHAP). In the fourth stage, presented strategies were ranked based on pairwise comparison using FHAP.

From the analysis of weaknesses, strengths, opportunities and threats facing AC for entrepreneurship, 12 strategies were presented in 4 groups of aggressive, conservative, competitive and defensive.

The literature review showed that no research has been done so far to identify strengths, weaknesses, opportunities and threats facing university entrepreneurship, especially AC. So the present study analyzes the weaknesses, strengths, opportunities and threats and proposes practical strategies for moving toward the formation of entrepreneurship AC. According to the gaps in providing SWOT of the AC, the results of this research can pave the way for policy makers and planners in this field.

Uninterruptible Power Supply (UPS) systems are typically designed to provide power to computers for five to thirty minutes after all utility company power has failed. In addition to providing blackout and brownout protection, many UPS systems also protect against spikes, surges, sags, and noise, and some also offer many of the features found in power distribution units (PDUs). The major components or subsystems of a typical UPS system are detailed, and a sample bid specification is appended. Three sidebars discuss UPSs and air conditioning, the maintenance bypass switch (MBS), and literature for further reading.

Investigates the differences in protocols between arbitral tribunals and courts, with particular emphasis on US, Greek and English law. Gives examples of each country and its way of using the law in specific circumstances, and shows the variations therein. Sums up that arbitration is much the better way to gok as it avoids delays and expenses, plus the vexation/frustration of normal litigation. Concludes that the US and Greek constitutions and common law tradition in England appear to allow involved parties to choose their own judge, who can thus be an arbitrator. Discusses e‐commerce and speculates on this for the future.