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A large number of high-frequency harmonic voltages exist in the output voltage of the inverter, which will affect the performance of the motor. The purpose of this paper is to obtain the influence of high frequency harmonic voltage on the performance of the line start permanent magnet synchronous motor (LSPMSM) and reveal the mechanism of influence. The research results can provide help for the design of LSPMSM driven by inverter drives.

First, the actual output voltage data of the inverter is collected, and then the fundamental voltage and high frequency harmonic voltage data can be obtained by performing the fast Fourier transformation method on the voltage data. Second, the finite element model is established. During the finite element calculation, the obtained fundamental voltage and the main harmonic voltage components are used as the voltage source. To research the effect of high frequency harmonic voltage on the performance of motor, a reference group without high frequency harmonic voltage is set up, which is used to compare and analyze the effect of high-frequency harmonics on the performance of the motor. To verify the correctness of the model, a prototype based on the model parameters is manufactured, and then the back EMF experiment and load experiment are performed. The test data and calculation results are compared and analyzed.

The coupling relationship between high frequency time harmonic magnetic field and low frequency space harmonic magnetic field is obtained. The stator copper loss and rotor eddy-current loss are calculated and analyzed under normal supply voltage and abnormal supply voltage, and the influence mechanism is revealed

The coupling relationship between high frequency time harmonic magnetic field and low frequency space harmonic magnetic field is obtained. The sensitivity of the high frequency harmonic voltage to the stator copper loss and rotor eddy-current loss is obtained, and the mechanism of losses change is revealed.

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.

The purpose of this paper is to reduce the inrush current and dip in voltage for energy‐ saving purposes in relation to residential air‐conditioning systems.

The paper focuses on the experimental harmonic investigation of a window‐type residential AC unit line current under time‐based soft‐starting control strategy. The control strategy assumes that only source voltage and current measurements are available. The soft‐starter is based on power electronic devices controlled through a firing signal generated by a programmed microcontroller during the first 500 ms.

The harmonic content shows the effect of the soft‐starter in exciting high‐frequency components of the line current. Harmonics investigations show that the high frequencies – even or odd multiples – of the fundamental line frequency are all excited by the soft‐starter approach. Some of these frequencies may harm the life cycle of the air‐conditioner.

The real data harmonic analysis shows that the adopted approach excites the entire frequency spectrum of the signal. A better monitoring of the harmonics is required. A closed loop adaptive soft‐starting control may perform much better than a time‐based soft‐starting strategy.

The paper assesses the power quality related to time‐based soft‐starting strategy of a residential air‐conditioning system to reduce the inrush current and the dip in voltage, both with a serious effect on energy savings, especially when the AC load is around 65 per cent of the total power demand load.

These implementations not only generate excessive voltage levels to enhance the quality of power but also include a detailed investigating of the various modulation methods and control schemes for multilevel inverter (MLI) topologies. Reduced harmonic modulation technology is used to produce 11-level output voltage with the production of renewable energy applications. The simulation is done in the MATLAB/Simulink for 11-level symmetric MLI and is correlated with the conventional inverter design.

This paper is focused on investigating the different types of asymmetric, symmetric and hybrid topologies and control methods used for the modular multilevel inverter (MMI) operation. Classical MLI configurations are affected by performance issues such as poor power quality, uneconomic structure and low efficiency.

The variations in both carrier and reference signals and their performance are analyzed for the proposed inverter topologies. The simulation result compares unipolar and bipolar pulse-width modulation (PWM) techniques with total harmonic distortion (THD) results. The solar-fed 11-level MMI is controlled using various modulation strategies, which are connected to marine emergency lighting loads. Various modulation techniques are used to control the solar-fed 11-level MMI, which is connected to marine emergency lighting loads. The entire hardware system is controlled by using SPARTAN 3A field programmable gate array (FPGA) board and the least harmonics are obtained by improving the power quality.

The simulation result compares unipolar and bipolar PWM techniques with THD results. Various modulation techniques are used to control the solar-fed 11-level MMI, which is connected to marine emergency lighting loads. The entire hardware system is controlled by a SPARTAN 3A field programmable gate array (FPGA) board, and the power quality is improved to achieve the lowest harmonics possible.

Gives introductory remarks about chapter 1 of this group of 31 papers, from ISEF 1999 Proceedings, in the methodologies for field analysis, in the electromagnetic community. Observes that computer package implementation theory contributes to clarification. Discusses the areas covered by some of the papers ‐ such as artificial intelligence using fuzzy logic. Includes applications such as permanent magnets and looks at eddy current problems. States the finite element method is currently the most popular method used for field computation. Closes by pointing out the amalgam of topics.

Static inverters are very important for the emergency energy distribution system of aircraft and similar machines. At the same time, the electrical energy produced at high frequency for electrical devices is used to reduce the weight of the cables in the aircraft and spacecraft because of the skin effect. In the high-frequency system, a thinner cable cross-section is used, and a great weight reduction occurs in the aircraft. So, fuel economy, less and late wear of the materials (landing gear, etc.) can be obtained with decreasing weight. This paper aims to present the development of a functional multilevel inverter (FMLI) with fractional sinus pulse width modulation (FSPWM) and a reduced number of switches to provide high-frequency and quality electrical energy conversion.

After the production of FSPWM for FMLI with a reduced component, which, to the best of the authors’ knowledge, is presented for the first time in this study, is explained step by step, and eight operating states are given according to different FSPWMs operating the circuit. The designed inverter and modulation technique are compared by testing the conventional modular multilevel inverter on different loads.

According to application results, it is seen that there is a 50% reduction in cross-section from 100 Hz to 400 Hz with the skin effect. At 1000 Hz, there is a 90% cross-section reduction. The decrease can be in cable weights that may occur in aircraft from 10 kg to 100 kg according to different frequencies. It causes less harmonic distortion than conventional converters. This supports the safer operation of the system. Compared to the traditional system, the proposed system provides more amplitude in converting the source to alternating voltage and increases the efficiency.

FSPWM is developed for multilevel inverters with reduced components at the high frequency and cascaded switching studies in the power electronics of aircraft.

Although the proposed system has less current and power loss as mentioned in the previous sections, it contains fewer power elements than conventional inverters that are equivalent for different hardware levels. This not only reduces the cost of the system but also provides ease of maintenance. To reduce the cable load in aircraft and create more efficient working conditions, 400 Hz alternative voltage is used. The proposed system causes less losses and lower harmonic distortions than traditional systems. This will reduce possible malfunctions and contribute to aircraft reliability for passengers and cargo. As technology develops, it is revealed that the proposed inverter system will be more efficient than traditional inverters when devices operating at frequencies higher than 400 Hz are used. With the proposed inverter, safer operation will be ensured, while there will be less energy loss, less fuel consumption and less carbon emissions to the environment.

The proposed inverter structure shows that it can provide energy transmission for electrical devices in space and aircraft by using the skin effect. It also contains less power elements than the traditional inverters, which are equivalent for different levels of hardware.

Doubly fed induction generator (DFIG) is widely used in wind energy conversion systems and it can operate with other primary movers. The purpose of this paper is to focus on the standalone operation of DFIG which may expand the area of possible applications and increase capabilities of the generation system in terms of power quality.

Synthesis of the control method was preceded by analysis of mathematical model of the machine. The control method based on the negative sequence and high harmonics extraction has been developed and verified in the laboratory unit. Control of the fundamental frequency component uses neither rotor speed nor position sensors.

The original method allows to compensate negative sequence and high harmonics of the generated voltage. At the same time, due to the active filtering capability of the grid side converter, the stator phase current shape is close to sine wave. Thus, it is seen by the machine as a linear load, what eliminates the electromagnetic torque ripples.

The system and control method can be applied in variable speed generation systems, e.g. wind turbines or diesel engines operating in the standalone mode.

Although the selective compensation of negative sequence and harmonics are known in the literature, until now the methods have been verified for the system with a rotor position sensor. Moreover, the stator current feed-forward improving the transient properties, as well as results of transient states caused by the load step change, have not been proposed in publications.

Multilevel inverters play a major role in the development of high-power industrial applications. In traditional low-level inverters (e.g. 2-level), the switching frequency is restricted and the harmonic spectrum of the system is hard to meet power requirements. Similarly, high-level inverters consist of a large number of switches, complex modulation techniques and complex hardware architecture, which results in high power loss and a significant amount of harmonic distortion. Furthermore, it is a must to ensure that every switch experiences the same stress of voltage and current. The purpose of this paper is to present an inverter topology with lower conduction and switching losses via reduced number of switches and equal voltage source-sharing technique.

Herein, the authors present a cascaded multilevel inverter having less power switches, a simple modulation technique and an equal voltage source-sharing phenomenon implementation.

The modulation technique becomes more complex when equal voltage source-sharing is to be implemented. In this study, a novel topology for the multilevel inverter with fewer switches, novel modulation technique, equal voltage source-sharing and Inductor-Capacitor-Inductor filter implementation is demonstrated to the reduce harmonic spectrum and power losses of the proposed system.

The nine-level inverter design is validated using software simulations and hardware prototype testing; the power losses of the proposed inverter design are elaborated and compared with the traditional approach.

The purpose of this paper is to discuss a new method of iron loss estimation under pulse width modulation (PWM) converter supply. The proposed method concerns the longitudinal magnetisation.

A novel method of iron loss estimation applies values of iron losses that come from a single higher harmonic coexisting with a DC‐bias field. This method considers non‐linearity of ferromagnetic. Results of estimation are validated using experimental results.

The paper formulates that the dependence of iron losses come from harmonics, on DC‐bias field. Moreover, it formulates possibilities of their utilization to iron loss estimation in case of deformed flux. On the other hand, it discusses the influence of DC‐bias field on static hysteresis and classical eddy current losses.

Experimental verification will still be needed as to the accuracy of the proposed model and applicability to various magnetic materials.

The paper provides an easy mathematical method of iron loss estimation, under PWM voltage supply.

The paper explains how to use an analytical method and results of iron losses come from single harmonics, obtained under coexistence with DC‐bias field, to iron loss estimation in case of longitudinal magnetisation where deformed magnetic flux occurs.

The purpose of this paper is to consider both sides of a back‐to‐back AC‐DC‐AC interface.

The paper presents a mathematical analysis, simulation, laboratory test in scaled model.

The two main findings comprised concept of control methods for grid AC‐DC‐AC converter applied in renewable energy sources with variable speed operation under distorted grid. Active filtering functionality in case of non‐linear current of a parallel load. Second, a control algorithm dedicated for two‐level AC‐DC converter applied in industrial networks with high‐order harmonics compensation working under hard conditions – balanced and unbalanced voltage dips.

The paper shows preliminary results for AC‐DC‐AC converter and active filter (AF) during voltage dips and for harmonics compensation. Control methods and/or topology should be improved and tested in scale and after at high‐power system.

Power quality supplied/received to/from the grid can be increased. In case of low‐cost system only AF can be applied to existing non‐linear receivers. Moreover, in case of full AC‐DC‐AC converter energy saving and production is possible.

Presented control methods give satisfactory results. Paper presents laboratory results for grid and machine side two different power circuits during steady states and transients. Moreover, active filtering operation during voltage dips is presented.