scholarly journals The Phase Shifting Soft Startup of L-LLC Resonant Bidirectional DC-DC Converter Based on Current-Limiting Curve

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Jing Lu ◽  
Xiangqian Tong ◽  
Ming Shen ◽  
Jun Yin ◽  
Yongtao Yuan
Keyword(s):  
Phase Shift ◽  
Control Strategy ◽  
Output Voltage ◽  
Phase Shifting ◽  
Soft Start ◽  
Phase Shift Angle ◽  
Current Limiting ◽  
Current Curve ◽  
Resonance Current ◽  
Shift Angle

The new L-LLC resonant bidirectional DC-DC converter (L-LLC-BDC) will produce a large resonance current and voltage inrush during the startup, posing a threat to the safe operation of the power device. Although a very high starting frequency can effectively suppress the inrush, it will also increase the output current demand of the driving ICs. This paper proposes a phase-shifting soft-start control strategy based on the current-limiting curve. Using operating mode analysis, the peak value of the resonant current is limited according to the output voltage and the phase shift angle of the switch, with the limit current curve at the startup stage drawn. By this current curve, a one-to-one correspondence between the output voltage and the phase shift angle of the switch is obtained. The phase-shifted soft-start control strategy can quickly establish the output voltage on the basis of a resonant frequency and can effectively suppress the resonance current inrush. An experimental prototype with a power of 6 kW and an input of 760 V and an output of 380 V is built. The experimental results prove the correctness and effectiveness of the soft start control strategy proposed in this paper.

scholarly journals Design and digital implementation of power control strategy for grid connected photovoltaic inverter

2019 ◽  
Vol 10 (3) ◽  
pp. 1564 ◽  
Author(s):  
Linda Hassaine ◽  
Mohamed Rida Bengourina
Keyword(s):  
Phase Shift ◽  
Power Control ◽  
Control Strategy ◽  
Digital Control ◽  
Optimization Design ◽  
Power Calculation ◽  
Digital Implementation ◽  
Grid Voltage ◽  
Phase Shift Angle ◽  
Shift Angle

<p class="Abstract">This paper presents the optimization design and a detailed implementation in FPGA (Field-Programmable Gate Array) of a power control strategy. This strategy is based on the phase shift angle of the inverter output voltage with respect to the grid voltage and DSPWM (Digital Sinusoidal Pulse Width Modulation) patterns “Phase shift angle-DSPWM” for an inverter for photovoltaic system connected to the grid. The proposed control can synchronize a sinusoidal inverter output current with a grid voltage and control the power injected into the grid. Detailed development of a digital controller with lower hardware and computation requirement is proposed. Description on the digital implementation of the A/D converter, the PI compensator, the phase shift and the DPWM, is provided. This digital control exhibit simplicity, reduction of the memory requirements and power calculation for the control. The functional structure of this system with digital control has been validated with simulations and experimental results.</p>

Steady‐state modeling of a phase‐shift PWM parallel resonant converter

2006 ◽  
Vol 25 (4) ◽  
pp. 883-899
Author(s):  
İres İskender ◽  
Yıldürüm Üçtug˘ ◽  
H. Bülent Ertan
Keyword(s):  
Mathematical Model ◽  
Steady State ◽  
Phase Shift ◽  
Analytical Model ◽  
Output Voltage ◽  
Resonant Converters ◽  
Resonant Converter ◽  
Content Type ◽  
Phase Shift Angle ◽  
Shift Angle

PurposeTo derive an analytical model for a dc‐ac‐dc parallel resonant converter operating in lagging power factor mode based on the steady‐state operation conditions and considering the effects of a high‐frequency transformer.Design/methodology/approachA range of published works relevant to dc‐ac‐dc converters and their control methods based on pulse‐width‐modulation technique are evaluated and their limitations in output measurement of higher output voltage converters are indicated. The circuit diagram of the converter is described and the general mathematical model of the system is obtained by deriving and combining the mathematical models of the different converter blocks existing in the system. The derived mathematical model is used to study the steady‐state and transient performance of the converter. The deriving procedure of the analytical model for a parallel resonant converter is extensively given and the analytical model obtained is verified by simulation results achieved using MATLAB/SIMULINK and the program written by the authors.FindingsThe paper suggests an analytical model for dc‐ac‐dc parallel resonant converters. The model can be used in the output voltage estimation of a converter in terms of its phase‐shift angle and the dc‐link voltage.Research limitations/implicationsThe resources in the library of the authors' university and also the English resources relative to dc‐ac‐dc converters reachable through the internet were researched.Practical implicationsThe analytical model suggested can be used in estimating the output voltage of the converters used in high‐voltage applications or where there are difficulties in employing sensors in measurement of the output voltage due to high price or implementation problems.Originality/valueThe originality of the paper is to present an analytical model for dc‐ac‐dc parallel resonant converters. Using this model makes it possible to estimate the output voltage of the converter using the dc‐link voltage and the phase‐shift angle. The proposed model provides researchers to regulate the output voltage of the converters using feed‐forward control technique.

scholarly journals Reduction of Total Harmonic Distortion (THD) on Multilevel Inverter with Modified PWM using Genetic Algorithm

2017 ◽  
Vol 5 (1) ◽  
pp. 91-118 ◽  
Author(s):  
Lucky Pradigta Setiya Raharja ◽  
Ony Asrarul Q. ◽  
Zainal Arief ◽  
Novie Ayub Windarko
Keyword(s):  
Genetic Algorithm ◽  
Phase Shift ◽  
Harmonic Distortion ◽  
Multilevel Inverter ◽  
Total Harmonic Distortion ◽  
Phase Shift Angle ◽  
Harmonic Injection ◽  
Harmonic Voltage ◽  
Shift Angle

In this research, modified PWM has been applied to the multilevel inverter (MLI) single-phase three-level diode clamp full bridge. Modified PWM is performed to produce minimum Total Harmonic Distortion (THD) the voltage because the quality of the good voltage is indicated by small THD. The THD indicates the quality of AC voltage source. The THD standard by the IEEE STD 519-1992 Harmonic Voltage Limits is 5% and the Pacific Corp standard is 8%, if the THD value is greater than the THD standard it can cause the electronic load to be damaged due to the damaged waveform. Modified PWM is applied by adding a 50 Hz sinusoidal reference signal with a sinusoidal signal which has a certain amplitude, frequency and phase shift angle. The frequency of the adder signal is the frequency at which the value of the individual harmonic voltage appears (n harmonic). To get maximum result, optimization using Genetic Algorithm (GA) method to determinate amplitude & phase shift angle done. The result of implementation hardware with modified PWM shows smaller THD voltage compared to the THD voltage with Sinusoidal Pulse Width Modulation (SPWM) switching up to 0.19 or decrease 65,51 % for modified PWM of harmonic injection n = 7 with GA optimization ma= 0.8 (A=0.0936 and ø = 0 rad) and up to 0.08 or decrease 12,30 % for modified PWM of harmonic injection n = 22 with GA optimization ma = 0.4 (A=0.1221 and ø = 0 rad).

scholarly journals Cellulose Ester Insulation of Power Transformers: Researching the Influence of Moisture on the Phase Shift Angle and Admittance

Energies ◽  
2020 ◽  
Vol 13 (20) ◽  
pp. 5511 ◽  
Author(s):  
Pawel Zukowski ◽  
Przemyslaw Rogalski ◽  
Tomasz N. Koltunowicz ◽  
Konrad Kierczynski ◽  
Jan Subocz ◽  
...  
Keyword(s):  
Activation Energy ◽  
Relaxation Time ◽  
Phase Shift ◽  
Cellulose Ester ◽  
Energy Value ◽  
Synthetic Ester ◽  
Phase Shift Angle ◽  
Increasing Temperature ◽  
Frequency Temperature ◽  
Shift Angle

This study investigates the frequency–temperature relations between the phase angle φ and admittance Y for composites of cellulose, synthetic ester, and water nanoparticles. We determined the activation energy value for the relaxation time of a phase shift angle ΔWφ ≈ (0.783 ± 0.0744) eV, which was related to the shift of φ(f) waveforms in higher frequency area with increasing temperature. We found that the position of admittance frequency waveforms in double logarithmic coordinates was simultaneously influenced by the temperature dependence of admittance and its relaxation time. Activation energy values for the relaxation time of admittance ΔWτ ≈ (0.796 ± 0.0139) eV and the activation energy value of admittance ∆WY ≈ (0.800 ± 0.0162) eV were determined. It was found that all three activation energy values were identical and their average was ΔW ≈ (0.793 ± 0.0453) eV. Impregnation with synthetic ester resulted in a decrease of activation energy by 0.26 eV compared to the impregnation with insulating oil. This was related to higher dielectric permittivity of the synthetic ester.

scholarly journals Loss Factor Behavior of Thermally Aged Magnetorheological Elastomers

Materials ◽  
2021 ◽  
Vol 14 (17) ◽  
pp. 4874
Author(s):  
Siti Aishah Abdul Aziz ◽  
Saiful Amri Mazlan ◽  
Ubaidillah Ubaidillah ◽  
Norzilawati Mohamad ◽  
Michal Sedlacik ◽  
...  
Keyword(s):  
Phase Shift ◽  
Rheological Properties ◽  
Polymer Composites ◽  
Loss Factor ◽  
Thermal Exposure ◽  
Deformation Condition ◽  
Phase Shift Angle ◽  
Temperature Exposure ◽  
Damping Materials ◽  
Shift Angle

Polymer composites have been widely used as damping materials in various applications due to the ability of reducing the vibrations. However, the environmental and surrounding thermal exposure towards polymer composites have affected their mechanical properties and lifecycle. Therefore, this paper presents the effect of material-temperature dependence on the loss factor and phase shift angle characteristics. Two types of unageing and aging silicone-rubber-based magnetorheological elastomer (SR-MRE) with different concentrations of carbonyl iron particles (CIPs), 30 and 60 wt%, are utilized in this study. The morphological, magnetic, and rheological properties related to the loss factor and phase shift angle are characterized using a low-vacuum scanning electron microscopy, and vibrating sample magnetometer and rheometer, respectively. The morphological analysis of SR-MRE consisting of 30 wt% CIPs revealed a smoother surface area when compared to 60 wt% CIPs after thermal aging due to the improvement of CIPs dispersion in the presence of heat. Nevertheless, the rheological analysis demonstrated inimitable rheological properties due to different in-rubber structures, shear deformation condition, as well as the influence of magnetic field. No significant changes of loss factor occurred at a low CIPs concentration, whilst the loss factor increased at a higher CIPs concentration. On that basis, it has been determined that the proposed changes of the polymer chain network due to the long-term temperature exposure of different concentrations of CIPs might explain the unique rheological properties of the unaged and aged SR-MRE.

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