• Title/Summary/Keyword: DC-link voltage fluctuation

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New Backstepping-DSOGI hybrid control applied to a Smart-Grid Photovoltaic System

  • Nebili, Salim;Benabdallah, Ibrahim;Adnene, Cherif
    • International Journal of Computer Science & Network Security
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    • v.22 no.4
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    • pp.1-12
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    • 2022
  • In order to overcome the power fluctuation issues in photovoltaic (PV) smart grid-connected systems and the inverter nonlinearity model problem, an adaptive backstepping command-filter and a double second order generalized Integrators (DSOGI) controller are designed in order to tune the AC current and the DC-link voltage from the DC side. Firstly, we propose to present the filter mathematical model throughout the PV system, at that juncture the backstepping control law is applied in order to control it, Moreover the command filter is bounded to the controller aiming to exclude the backstepping controller differential increase. Additionally, The adaptive law uses Lyapunov stability criterion. Its task is to estimate the uncertain parameters in the smart grid-connected inverter. A DSOGI is added to stabilize the grid currents and eliminate undesirable harmonics meanwhile feeding maximum power generated from PV to the point of common coupling (PCC). Then, guaranteeing a dynamic effective response even under very unbalanced loads and/or intermittent climate changes. Finally, the simulation results will be established using MATLAB/SIMULINK proving that the presented approach can control surely the smart grid-connected system.

Simplified Space Vector PWM Method for Multi-level Inverters (멀티레벨 인버터를 위한 간략화된 공간 전압벡터 변조 방안)

  • Suh, Jae-Hyeong;Song, Young-Joo;Kim, Kwang-Seob;Lee, Chul-Goo;Bang, Sang-Seok;Choi, Chang-Ho;Hyun, Dong-Seok
    • Proceedings of the KIEE Conference
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    • 1998.07f
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    • pp.1905-1907
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    • 1998
  • The multi-level approach seems to be best suited to high power, high voltage ac drives with low torque ripple and fast dynamic response. If high control performance is required, space vector control becomes desirable, and the task becomes time critical. In this paper, a simplified space vector PWM method for the control of a three level inverter is proposed. As the PWM is simple in structure, it is easy to implement and the fluctuation of the neutral point potential of DC link can be supressed effectively. The simulation results demonstrate that the proposed PWM strategy can be applied to high power, high voltage inverter systems. And its application to multi-level inverter is easily done on the same principle.

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Approximate SHE PWM for Real-Time Control of 2-Level Inverter (3레벨 인버터의 실시간 제어를 위한 근사화 SHE PWM)

  • 박영진;홍순찬
    • The Transactions of the Korean Institute of Power Electronics
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    • v.3 no.4
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    • pp.365-374
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    • 1998
  • The SHE(Selected Harmonic Elimination) PWM scheme which eliminates specific lower order harmonics can generate h high quality output waveforms in 3-level PWM inverters. However. its application has limited since SHE switching a angles cannot be calculated on-line by a microprocessor-implemented control system. Based on off-line optimization. in which multiple SHE solutions were found and analysed for 2 to 5 switching angles per quarter in the 3-level SHE PWM pattern. this paper presents an algebraic algorithm for an ordinary microprocessor to calculate approximate SHE S switching angles on-line with such high resolution that it makes no practical difference between the accurate and the a approximate SHE switching angles. By employing the variable of the dc-link voltage Vdc' the proposed SHE PWM p pattern can ideally compensate the dc input fluctuation together with selected harmonics eliminated.

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