A Double-Boost Converter Based on Coupled Inductance and Magnetic Integration

High-voltage gain converter has a high-frequency use in some industrial fields, for instance, the fuel cell system, the photovoltaic system, electric vehicles, and the high-intensity discharge lamp. In order to solve the problem of the low-voltage gain of traditional boost converter, the double-boost converter with coupled inductance and doubled voltage is proposed, which connects the traditional boost converter in parallel. The voltage gain of the converter is further improved by introducing the voltage-doubled unit of the coupled inductance. Moreover, the clamp capacitor can absorb the leakage inductance in the circuit and reduce the voltage stress of the switch. In addition, two coupled inductors are magnetically collected; then, the loss of the core is analyzed under the same gain. The detailed analysis of the proposed converter and a comparison considering other topologies previously published in the literature are also presented in this article. In order to verify the proposed converter performance, a prototype has been built for a power of 200 W, input and output voltages of 12 and 84 V, respectively, and a switching frequency of 50 kHz. Experimental results validate the effectiveness of the theoretical analysis proving the satisfactory converter performance, whose peak efficiency is 95.5%.

Small-Signal Modeling of Phase-Shifted Full-Bridge Converter Considering the Delay Associated to the Leakage Inductance

This paper demonstrates that in the Phase-Shifted Full-Bridge (PSFB) buck-derived converter, there is a random delay associated with the blanking time produced by the leakage inductance. This random delay predicts the additional phase drop that is present in the frequency response of the open-loop audio-susceptibility transfer function when the converter shows a significant blanking time. The existing models of the PSFB converter do not contemplate the delay and gain differences associated to voltage drop produced in the leakage inductor of the transformer. The small-signal model proposed in this paper is based on the combination of two types of analysis: the first analysis consists of obtaining a small-signal model using the average modeling technique and the second analysis consists of studying the natural response of the power converter. The dynamic modeling of the Phase-Shifted Full-Bridge converter, including the random delay, has been validated by simulations and experimental test.

An improved new transformer type arc suppression reactor

In this paper, to accurately compensate the arc suppression coil, the structure of the transformer is improved. Here, a fixed inductive element is connected in series with the short-circuit winding, which combines with the leakage inductance of the original transformer to form a new short circuit impedance. The improved transformer reduces the manufacturing cost and difficulty of the controllable inductor, reduces the requirements for the winding of the reactor, and makes the manufacturing easier.

Once again about the Steinmetz transformer model and the ongoing subdivision of its leakage inductance

Purpose Despite its well-founded criticism and lack of proper justification under core saturation conditions, the T-equivalent transformer model (Steinmetz scheme) is obviously championing in the literature. This educational paper aims to explain in a simple manner the limitations of the T-model of a low-frequency transformer and critically analyses some attempts to improve it. Design/methodology/approach Using a simplified examination of magnetic fluxes in the core and windings and using the modeling in ATPDraw, it is shown that transient transformer models with the indivisible leakage inductance allow circumventing the drawbacks of the T-model. Findings The authors show the absence of valid grounds for subdividing the leakage inductance of a transformer between its primary and secondary windings. The connection between the use of individual leakage inductances and inaccurate prediction of inrush current peaks is outlined as an important example. Practical implications The presented models can be used either as independent tools or serve as a reference for subsequent developments. Social implications Over generations, the habitual transformer T-equivalent is widely used by engineers and Electromagnetic Transients Program experts with no attention to its inadequacy under core saturation conditions. Having studied typical winding configurations, the authors have shown that neither of them has any relation to the T-equivalent. Originality/value This educational paper will contribute to the correct understanding of the transients occurring in a transformer under abnormal conditions such as inrush current or ferroresonance events, as well as during an out-of-phase synchronization of step-up generator transformers.

Challenges in Winding Design and Thermal Calculations: Physical Model of Permanent Magnet Synchronous Machine

Interest in multilayer windings is increasing with the application of the hairpin winding technology to the manufacturing of electrical machines. Therefore, the four-layer fractional slot concentrated winding is used for the initial design of the machine in this paper. The proposed physical model of the machine uses winding with a relatively high number of turns which is inappropriate to hairpin winding. Therefore the round-wire winding is created and the three-layer winding is derived and analyzed including the effect on the slot leakage inductance. The thermal analysis is then applied to the physical model of the machine to evaluate the slot-related thermal properties of the slot and the whole machine. The measurement is compared with the finite element analysis (FEA) and the equivalent slot thermal conductivity and heat transfer coefficients of the stator and rotor are obtained.