Wyniki wyszukiwania - BazTech

1

Development of energy-efficient IBC with IGBT module for photovoltaic applications

Kumar C. Prasanna, Rao Anand

Power Electronics and Drives

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2020

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Vol. 5 (40)

73--81

EN

The proposed study is improvised value-engineered modifications for the basic interleaved boost converter (IBC) by including relevant modifications in circuits, which is expected for a better performance in switching with reduction in losses. The newly modified IBC circuit with insulated gate bipolar transistor (IGBT) along with converter has been experimented by simulations and the results are tabulated to modified IBC with metal oxide silicon field effect transistors. Further experimental analysis and validations of the proposed simulation with hardware developed adopting model SKM195GB066D consisting of IGBTs is presented. This study further enhances and summarises the optimum utilisation and the performance of IBC with the proposed IGBT modules that synchronises power diode. Enhancing the simulation outcomes, the hardware is proposed and developed to be tested for a load up to 1.5 kW with the evaluation of key parameters such as efficiency of the converter.

2

Improved carrier phase shift modulation and voltage equalization control strategy in modular multilevel converter

Jin Hongtao, Luo Yinghong, Fan Yuheng, Pan Shengxiong

Archives of Electrical Engineering

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2019

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Vol. 68, nr 4

803--815

EN

In order to solve the problem of traditional carrier phase-shift modulation with multiple ratios or PI controllers and cumbersome tuning parameters, this paper uses improved carrier phase-shift modulation. The total turn-on number of sub-modules each bridge arm is determined by comparing the sinusoidal modulated wave with the triangular carrier, and then the control signal is generated according to the capacitance voltage sorting result and the bridge arm current polarity. However, this modulation method uses a sorting method that causes the insulated gate bipolar transistor (IGBT) have an excessively high switching frequency. Therefore, a sorting trigger condition that can effectively reduce the switching frequency is used. The method determines whether to reorder based on the error between the voltage average and the actual value. For the circulation problem, the double-frequency negative sequence component is extracted by rotating coordinate transformation, and it is suppressed by PI control. A 21-level MMC model was built in MATLAB/simulink to analyze the sub-module capacitor voltage fluctuation, output current, voltage distortion rate and bridge arm circulation. It is verified that the modulation method can combine the sorting algorithm and circulation suppression method at the same time, and has better voltage equalization and circulation suppression effects.

3

Research on the operational performance of high speed permanent magnet generator with controlled rectifier in distributed generation

Hongbo Q., Yanqi W., Cunxiang Y., Kaiqiang H.

Archives of Electrical Engineering

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2018

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Vol. 67, nr 4

899--913

EN

The uncontrolled rectifier and controlled rectifier which use fixed switching frequency control strategy are applied usually during the working of a high-power high- speed permanent magnet generator (HSPMG). Even for the controlled rectifier, it will generate harmonics. The electromagnetic performance of the HSPMG is also affected by these harmonics. In this paper, the influences of the fixed switching frequency control strategy on a HSPMG were studied. Based on the Fourier theory, the harmonic currents of the generator were analyzed, and the change of harmonic distribution range and current total harmonic distortion (THD) were obtained. By using an indirect field-circuit coupling method, the influences of the fixed switching frequency control strategy on the losses and torque of the generator were analyzed. The relations between the switching frequency and the losses and torque of the generator were obtained, and the change mechanism of the loss was revealed. The obtained conclusions can provide reference for the optimized choice of the switching frequency of the distributed generation system with the HSPMG. It can also provide support for the HSPMG electromagnetic structural optimization and the optimization of the loss and harmonic on the system level.

4

PSPICE simulation and design of a snubber circuit for power MOSFETs

Sunter S., Tatar Y.

Zeszyty Naukowe. Elektryka / Politechnika Łódzka

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1998

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z. 92

193--198

EN

In this paper, an R-C-D turn-off snubber circuit for power MOSFETs has been designed. Since the MOSFET operates at high switching frequencies and there is no way to avoid stray inductances in the circuit due to the connection cables, it is necessary to limit dv/dt of the MOSFET at turn-off. First, PSPICE model of the switching circuit has been obtained and then the effects of the connection cables on the MOSFET voltage has been demonstrated. An appropriate snubber circuit across the MOSFET has been used. The circuit which energies an inductive load from a dc supply has been designed by considering the results from the PSPICE model. Both simulation and experimental results are presented to confirm the correct operation of the snubber circuit.