Evaluation and Minimization of Total Harmonic Distortion in Three-Phase Two-Level Voltage Source Inverter with Low Switching Frequency

Three-phase four-leg voltage-source converters have been considered for some recent projects in smart grids and in the automotive industry, projects such as on-board electric vehicles (EVs) chargers, thanks to their built-in ability to handle unbalanced AC currents through the 4th wire (neutral). Although conventional carrier-based modulations (CBMs) and space vector modulations (SVMs) have been commonly applied and extensively studied for three-phase four-leg voltage-source converters, very little has been reported concerning their pollution impact on AC grid in terms of switching ripple currents. This paper introduces a thorough analytical derivation of peak-to-peak and RMS values of the AC current ripple under balanced and unbalanced working conditions, in the case of three-phase four-leg converters with uncoupled AC-link inductors. The proposed mathematical approach covers both phase and neutral currents. All analytical findings have been applied to two industry recognized CBM methods, namely sinusoidal pulse-width modulation (PWM) and centered PWM (equivalent to SVM). The derived equations are effective, simple, and ready-to-use for accurate AC current ripple calculations. At the same time, the proposed equations and diagrams can be successfully adopted to design the conversion system basing on the grid codes in terms of current ripple (or total harmonic distortion (THD)/total demand distortion (TDD)) restrictions, enabling the sizing of AC-link inductors and the determination of the proper switching frequency for the given operating conditions. The analytical developments have been thoroughly verified by numerical simulations in MATLAB/Simulink and by extensive experimental tests.

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Common-Mode Reduction SVPWM for Three-Phase Motor Fed by Two-Level Voltage Source Inverter

Energies ◽

10.3390/en13153884 ◽

2020 ◽

Vol 13 (15) ◽

pp. 3884

Author(s):

Jian Zheng ◽

Mingcheng Lyu ◽

Shengqing Li ◽

Qiwu Luo ◽

Keyuan Huang

Keyword(s):

High Frequency ◽

Pulse Width ◽

Pulse Width Modulation ◽

Voltage Source ◽

Switching Frequency ◽

Voltage Source Inverter ◽

Large Magnitude ◽

Common Mode ◽

Common Mode Voltage ◽

Three Phase

Aiming at the problem of large magnitude and high frequency of common-mode voltage (CMV) when space vector pulse width modulation (SVPWM) is used in a three-phase motor fed by a two-level voltage source inverter, a common-mode reduction SVPWM (CMRSVPWM) is studied. In this method, six new sectors are obtained by rotating six sectors of conventional SVPWM by 30°. In odd-numbered sectors, only three non-zero vectors with odd subscripts are used for synthesis, while in even-numbered sectors, only three non-zero vectors with even subscripts are used for synthesis. The actuation durations of three non-zero vectors in each switching period in each sector are given. Simulation and experimental results show that, compared with the conventional SVPWM, the CMV magnitude of CMRSVPWM is reduced by 66.67% and the CMV frequency of CMRSVPWM is reduced from the original switching frequency to the triple fundamental frequency. At the same time, the current, torque and speed of the motor are still good.

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A New Symmetric Multilevel Voltage Source Inverter with Least Number of Switches

10.29007/ldnz ◽

2018 ◽

Author(s):

Malu Prajapati

Keyword(s):

Output Power ◽

Power Loss ◽

Harmonic Distortion ◽

Multilevel Inverter ◽

Total Harmonic Distortion ◽

Voltage Source ◽

Voltage Source Inverter ◽

Voltage Level ◽

Driver Circuit ◽

Gate Driver

In this paper, a new symmetric multilevel voltage source inverter is proposed which consist less number of switches as compared to conventional multilevel inverter. This new symmetric MLI is able to produce desired value of voltage level with reduced number of switches. Also, multilevel inverter has good harmonic profile that is able to reduce total harmonic distortion without affecting desired output power. Moreover, in comparison with conventional cascade multilevel inverter, this new symmetric topology ultimately reduced the number of switches, the number of gate driver circuit, inverter cost, installation area and power loss due to reduced amount of on state switches.

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Design And Implementation of Two-Phase Interleaved Voltage Source Inverter For PV Applications

IIUM Engineering Journal ◽

10.31436/iiumej.v20i2.1142 ◽

2019 ◽

Vol 20 (2) ◽

pp. 127-141

Author(s):

HARIKA SRIDHARAN ◽

Seyezhai Ramalingam

Keyword(s):

Power Quality ◽

Harmonic Distortion ◽

Total Harmonic Distortion ◽

Voltage Source ◽

Voltage Source Inverter ◽

Two Phase ◽

Distortion Factor ◽

Matlab Simulink ◽

Pv Panel ◽

Current Ripple

ABSTRACT:The design of a voltage source inverter is challenging for PV-grid connected systems due to power quality issues. To improve the power quality,a two-phase interleaved voltage source inverter (IVSI) is proposed in this paper. IVSI phase shifts two voltage source inerters connected in parallel. The inverter topology is interfaced with a 40W PV panel employing a multiple maxima search (MMS) MPPT algorithm. This algorithm results in higher tracking efficiency compared to existing methods. Modelling of the PV with MPPT and the circuit configuration of the interleaved inverter is simulated in MATLAB/SIMULINK. The switches in the IVSI is controlled by employing a unipolar PWM technique. The performance of the IVSI is investigated in terms of weighted total harmonic distortion (WTHD), distortion factor (DF), harmonic spread factor (HSF), and inductor current ripple and compared with classical VSI. From the analysis, it is inferred that the proposed inverter results in reduced total harmonic distortion(THD) and decreased inductor current ripple thereby producing a high-quality output. The hardware model of the two-phase IVSI is developed and interfaced with PV where gating pulses are generated in FPGA. The simulation results are validated experimentally. ABSTRAK: Rekaan pembalik sumber voltan adalah mencabar pada sistem gabungan grid-PV disebabkan isu kualiti tenaga. Bagi memperbaharui kualiti tenaga, pembalik sumber voltan antara lembar dua-fasa (IVSI) telah dicadangkan dalam kajian ini. Anjakan fasa IVSI pembalik sumber voltan dua-fasa telah dihubungkan secara selari. Topologi pembalik telah diantaramukakan dengan 40W panel PV dengan mengunakan carian maksima berganda (MMS) algoritma MPPT. Hasil algoritma menunjukkan lebih tinggi keberkesanan dibandingkan dengan kaedah sedia ada. PV model dengan MPPT dan konfigurasi litar pembalik antaramuka telah disimulasi menggunakan MATLAB/SIMULINK. Suis dalam IVSI dikawal dengan menggunakan teknik PWM unipolar. Dapatan kajian ke atas IVSI adalah berdasarkan berat pengherotan total harmoni (WTHD), faktor pengherotan (DF), faktor sebaran harmoni (HSF), getaran arus pembalik dan dibandingkan dengan kaedah klasik VSI. Analisis menunjukkan kesimpulan dapatan kajian ke atas pembalik yang dicadangkan telah berkurang jumlah pengherotan harmoni (THD) dan getaran arus pembalik telah berkurang, oleh itu menghasilkan hasil akhir yang berkualiti tinggi. Model perkakasan IVSI dua-fasa telah dibangunkan dan diantaramukakan dengan PV di mana signal pengegetan dihasilkan dalam FPGA. Dapatan hasil simulasi telah disahkan secara eksperimen.

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Close Loop V/F control of Voltage Source Inverter using Sinusoidal PWM, Third Harmonic Injection PWM and Space vector PWM Method for Induction Motor

International Journal of Power Electronics and Drive Systems (IJPEDS) ◽

10.11591/ijpeds.v7.i1.pp217-224 ◽

2016 ◽

Vol 7 (1) ◽

pp. 217

Author(s):

Sandeep Ojha ◽

Ashok Kumar Pandey

Keyword(s):

Induction Motor ◽

Pulse Width ◽

Pulse Width Modulation ◽

Harmonic Distortion ◽

Total Harmonic Distortion ◽

Modulation Method ◽

Voltage Source ◽

Voltage Source Inverter ◽

Third Harmonic ◽

Simulink Model

<p>The aim of this paper to presents a comparative analysis of Voltage Source Inverter using Sinusoidal Pulse Width Modulation Method, Third Harmonic Injection Pulse Width Modulation Method and Space Vector Pulse Width Modulation Two level inverter for Induction Motor. In this paper we have designed the Simulink model of Inverter for different technique. An above technique is used to reduce the Total Harmonic Distortion (THD) on the AC side of the Inverter. The Simulink model is close loop. Results are analyzed using Fast Fourier Transformation (FFT) which is for analysis of the Total Harmonic Distortion. All simulation are performed in the MATLAB Simulink / Simulink environment of MATLAB.</p>

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Analysis of Equivalent Inductance of Three-phase Induction Motors in the Switching Frequency Range

Electronics ◽

10.3390/electronics8020120 ◽

2019 ◽

Vol 8 (2) ◽

pp. 120 ◽

Cited By ~ 1

Author(s):

Milan Srndovic ◽

Rastko Fišer ◽

Gabriele Grandi

Keyword(s):

Induction Motors ◽

Harmonic Distortion ◽

Voltage Source ◽

Switching Frequency ◽

Frequency Range ◽

Leakage Inductance ◽

Squirrel Cage ◽

Three Phase ◽

Ripple Amplitude ◽

Current Ripple

The equivalent inductance of three-phase induction motors is experimentally investigated in this paper, with particular reference to the frequency range from 1 kHz to 20 kHz, typical for the switching frequency in inverter-fed electrical drives. The equivalent inductance is a basic parameter when determining the inverter-motor current distortion introduced by switching modulation, such as rms of current ripple, peak-to-peak current ripple amplitude, total harmonic distortion (THD), and synthesis of the optimal PWM strategy to minimize the THD itself. In case of squirrel-cage rotors, the experimental evidence shows that the equivalent inductance cannot be considered constant in the frequency range up to 20 kHz, and it considerably differs from the value measured at 50 Hz. This frequency-dependent behaviour can be justified mainly by the skin effect in rotor bars affecting the rotor leakage inductance in the considered frequency range. Experimental results are presented for a set of squirrel-cage induction motors with different rated power and one wound-rotor motor in order to emphasize the aforesaid phenomenon. The measurements were carried out by a three-phase sinusoidal generator with the maximum operating frequency of 5 kHz and a voltage source inverter operating in the six-step mode with the frequency up to 20 kHz.

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