Influence of temperature on phase shift angle and admittance of moistened composite of cellulose and insulating oil

<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>

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

EMITTER International Journal of Engineering Technology ◽

10.24003/emitter.v5i1.174 ◽

2017 ◽

Vol 5 (1) ◽

pp. 91-118 ◽

Cited By ~ 1

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 Ã¸ = 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 Ã¸ = 0 rad).

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Coordination Control of Modulation Index and Phase Shift Angle for Current Stress Reduction in Isolated AC–DC Matrix Converter

IEEE Transactions on Power Electronics ◽

10.1109/tpel.2020.3023719 ◽

2021 ◽

Vol 36 (4) ◽

pp. 4585-4596

Author(s):

Fanxiu Fang ◽

Hao Tian ◽

Yunwei Li

Keyword(s):

Phase Shift ◽

Stress Reduction ◽

Matrix Converter ◽

Modulation Index ◽

Coordination Control ◽

Current Stress ◽

Phase Shift Angle ◽

Shift Angle

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

Energies ◽

10.3390/en13205511 ◽

2020 ◽

Vol 13 (20) ◽

pp. 5511 ◽

Cited By ~ 1

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.

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