In this study, the winding function method is modified and used to calculate the machine inductances in two different cases, namely, a healthy case and a short-circuited stator winding case. For the first time, a numerical air-gap function is used in addition to a model of the air gap of salient-pole machines which considers the stator slot effects. The modified winding function (MWF) method introduced here is more precise when compared with previous methods. This MWF enables one to compute the air-gap function more accurately. Also a mathematical model that allows taking stator and rotor core saturation into account in both healthy and faulty conditions is presented in this study. Stator and rotor winding currents in healthy and faulty condition, obtained from experimental results, are compared with simulation results to verify the accuracy of the proposed method.

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This paper presents the design, analysis, and fabrication of a new miniaturized microstrip branch line coupler (BLC) with high harmonics suppression. The T-shaped resonators, open stubs cross-shaped resonators and radial stubs are used in the proposed coupler design. The designed BLC operates at 1 GHz frequency, which can suppress up to 5th spurious harmonics with a 20 dB level of attenuation. High miniaturization of about 86% is obtained for the proposed BLC, which is corresponding to the normalized size of 0.009 λg2. The measured values of isolation and return loss are obtained 28 dB and 29 dB, respectively, while the measured insertion loss of better than 0.2 dB is achieved at the operating frequency. Additionally, the operating bandwidth of the designed coupler ranges from 0.905 GHz up to 1.105 GHz, which shows a 200 MHz operating bandwidth or a fractional bandwidth (FBW) of 20%. The presented BLC is fabricated and measured, where the measurements confirm the simulated results. The designed coupler shows desirable performance compared to the recent designed couplers.

Summary In this paper, a new combined impedance‐source network inverter (CISI) with high voltage gain in low duty cycle is presented. With common ground between the input source and the inverter bridge and a continuous input current, the proposed converter is a suitable choice for renewable energy applications. The duty cycle of the inverter switches is low, leading to a reduction in losses and improving the efficiency. Also, due to the small duty cycle, the modulation index can be increased, and as a result, the quality of output voltages and currents is greatly improved. The proposed circuit has no switch in the input impedance network, and the number of components is reasonable compared to other works. Another advantage of the proposed converter is the low voltage stress on its capacitors and diodes. The proposed circuit is designed and tested at 180 W. The experimental results and the calculated values are close to each other, verifying the accuracy of the analysis.

This study presents a new method to detect the magnet defects in permanent magnet (PM) machines by calculating the magnet's MMF function from the machine's electrical variables. The authors propose for the first time an inverse transformation to map the winding flux waveform into the corresponding magnet MMF function. The analysis of this function defines the fault occurrence and its position. The winding flux waveform is computed from the electrical variables and this study adopts a reduced order model of the magnetic equivalent circuit to define the direct and inverse transform between the magnet's MMF and the winding flux; for this reason the authors call the new approach the inverse transform method. A dedicated PM machine with a defective magnet has been constructed to validate the proposed method by comparing simulation and experimental results.