A best-fit model of power losses in cold rolled-motor lamination steel operating in a wide range of frequency and magnetization

A procedure is described for identifying a mathematical model of core losses in ferromagnetic steel based on a minimal amount of experimental data. The new model has a hysteresis loss multiplicative coefficient variable only with frequency, a hysteresis loss power coefficient variable both with frequency and induction and a combined coefficient for eddy-current and excess losses that is, within a set frequency range, variable only with induction. Validation was successfully performed on a large number of different samples of nongrain oriented fully and semiprocessed steel alloys. Over a wide range of frequencies between 20 Hz and 2.1 kHz and inductions from 0.05 up to 2 T, the errors of the proposed model are substantially lower than those of a conventional model with fixed value coefficients

Analysis and design of a two-speed single-phase induction motor with 2 and 18 pole special windings

The motor presented employs multiple independent windings for operation with two very different pole numbers. The 18-pole field is produced with a symmetrical three-phase winding connected in a Steinmetz arrangement to a single-phase supply. A unified analysis method has been developed and used to demonstrate the equivalence of a Steinmetz delta or star connection with a main and auxiliary winding of a single-phase motor. The method has been experimentally validated and also included are some specific motor design considerations

Assessment of torque components in brushless permanent-magnet machines through numerical analysis of the electromagnetic field

For the calculation of torque in brushless (BL) alternating current motors a local method is proposed, based on the Maxwell stress theory and the filtered contributions due to the harmonics of the magnetic vector potential in the motor air gap. By considering the space fundamental field only, the method can efficiently estimate the average synchronous torque for a variety or motor topologies, including concentrated winding designs. For BL direct current motor analysis a global method is introduced, based on the virtual work principle expressed in terms of energy components in various motor regions. The method leads to simplifications in the average torque calculation and enables the direct identification of the cogging and ripple components. The mathematical procedures have been validated against experiments and other numerical techniques

On the variation with flux and frequency of the core loss coefficients in electrical machines

A model of core losses, in which the hysteresis coefficients are variable with the frequency and induction (flux density) and the eddy-current and excess loss coefficients are variable only with the induction, is proposed. A procedure for identifying the model coefficients from multifrequency Epstein tests is described, and examples are provided for three typical grades of non-grain-oriented laminated steel suitable for electric motor manufacturing. Over a wide range of frequencies between 20-400 Hz and inductions from 0.05 to 2 T, the new model yielded much lower errors for the specific core losses than conventional models. The applicability of the model for electric machine analysis is also discussed, and examples from an interior permanent-magnet and an induction motor are included

Computation of core losses in electrical machines using improved models for laminated steel

Two new models for specific power losses in cold-rolled motor lamination steel are described together with procedures for coefficient identification from standard multifrequency Epstein or single sheet tests. The eddy-current and hysteresis loss coefficients of the improved models are dependent on induction (flux density) and/or frequency, and the errors are substantially lower than those of conventional models over a very wide range of sinusoidal excitation, from 20 Hz to 2 kHz and from 0.05 up to 2 T. The model that considers the coefficients to be variable, with the exception of the hysteresis loss power coefficient that has a constant value of 2, is superior in terms of applicability and phenomenological support. Also included are a comparative study of the material models on three samples of typical steel, mathematical formulations for the extension from the frequency to the time domain, and examples of validation from electrical machine studies

Iron loss calculation considering temperature influence in non-oriented steel laminations

In this study, the temperature influence on iron loss of non-oriented steel laminations is investigated. The iron loss variation under different flux densities, frequencies and temperatures is systematically measured and analysed by testing two typical non-oriented steel laminations, V300-35 A and V470-50 A. The iron loss variation with temperature is almost linear in the typical operating temperature range of electrical machines. Furthermore, the varying rate of iron loss with temperature varies with flux density and frequency. A coefficient which can fully consider the temperature influence is introduced to the existing iron loss model to improve the iron loss prediction accuracy. The predicted and measured results show that the temperature influence on the iron loss can be effectively considered by utilising the improved model, i.e. the prediction accuracy of the improved iron loss model remains constant, even when the temperature varies significantly. A potential simplification of this improved model is also discussed in this study

An Improved Structures of Modified CUK Converter using VLSI module (MCCVLSI) for High-Voltage Renewable Energy Applications

In this paper, an improved structures of modified CUK converter (MCCVLSI) is presented using Voltage Lift Switched Inductor (VLSI) module. The proposed converter provides a negative high DC voltage which is a doable solution for renewable energy applications. A three new modified CUK converter structures are derived with the help of VLSI module as; MCCVLSI-XLL, MCCVLSI-L YL and MCCVLSI-LLZ. The complete mathematical analysis is provided to calculated voltage conversion ratio. Moreover, the proposed structures are compared with each others in terms of voltage conversion ratio and number of components. The working mode of MCCVLSI-XLL is explained in details. The qualities of the presented structures are reviewed in details. The simulation results are provided and the obtained results show a good agreement with theoretical analysis. ? 2018 IEEE

A Novel Calculus Based Unipolar Double Reference Single Carrier PWM for Single Phase T-Multilevel Inverter with under Modulation (<1) for Renewable Energy Applications: Hardware Implementation

In this research treatise, a novel Calculus Based Unipolar Double Reference Single Carrier PWM (CB-UDR-SC PWM) is proposed for single phase T-Multilevel Inverter (T-MLI) for renewable energy applications. The main downsides of conventional two-level inverters are i) \boldsymbol{d}\boldsymbol{v}/\boldsymbol{d}\boldsymbol{t} of output voltage is high, ii) requirement of fast switching devices, iii) requirement of bulky filter, iv) Electromagnetic Interference is high, iv) temperature of switches is increases with high speed, v) not suitable for high power application and vi) high THD. Single switch with four diodes are used to design the auxiliary structure of T-MLI structure. Total 8 diodes (including anti-parallel diode of switch), five switches are used to design T-MLI for five-level. CB-UDR-SC PWM methodology is proposed by utilizing two modulation signals (derived from calculus) and single carrier. The technique is employed to investigate T-MLI circuitry is for the under-modulation index. The general idea of calculus based PWM is explained in detailed. SPARTAN 3E-XCS250E FPGA trainer kit is utilized to obtain PWM for the switches of T-MLI. Experimental and simulation results are provided which validates the concept and always shows a good agreement with theoretical approaches. ? 2018 IEEE.Scopu