Performance analysis of zero common‐mode voltage pulse‐width modulation techniques for three‐level neutral point clamped inverters

Power inverters produce common mode voltage (CMV) and common mode current (CMC) which cause high-frequency electromagnetic interference (EMI) noise, leakage currents in electrical drives application and grid-connected systems, which consequently drops the efficiency of the system considerably. This CMV can be mitigated by designing suitable EMI filters and/or investigating the effects of different modulation strategies. In this paper, the effect of various modulation techniques over CMV and CMC are investigated for two-level and three-level inverters. It is observed that the modified third harmonic injection method reduced the CMV and CMC in the system by 60%. This modified pulse width modulation (PWM) technique is employed along with EMI chokes which results in reduced distortion of the system.

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A Virtual Negative Resistor Based Common Mode Current Resonance Suppression Method for Three-Level Grid-Tied Inverter with Discontinuous PWM

Energies ◽

10.3390/en13071595 ◽

2020 ◽

Vol 13 (7) ◽

pp. 1595

Author(s):

Qiyu Li ◽

Hongwei Zhou ◽

Jiansong Zhang ◽

Shengdun Zhao ◽

Jingfeng Lu

Keyword(s):

Pulse Width ◽

Pulse Width Modulation ◽

Neutral Point ◽

Resonance Problem ◽

Common Mode ◽

Zero Sequence ◽

In Series ◽

Suppression Method ◽

Lc Filter ◽

Control Quantity

The output LC filter of a photovoltaic (PV) string three-level grid-tied inverter that connects the filter capacitor neutral point to dc-link capacitor neutral point can reduce the common-mode (CM) current injected to the grid by letting the CM current circulate within the inverter. However, the internal CM current may resonate because of the existence of the resonant frequency of the internal CM LC circuit. Compared with the traditional continuous pulse-width modulation (CPWM), the resonance can be worse if discontinuous pulse-width modulation (DPWM) is applied, for the zero sequence quantity of DPWM contains more harmonics than that of CPWM. In this paper, a virtual negative resistor based common mode current resonance suppression method for a three-level grid-tied inverter is proposed to overcome the CM current resonance problem in DPWM application. Different positions of the virtual negative resistor in the equivalent CM circuit with different feedback variables are analyzed theoretically. The virtual negative resistor connected in series with the inductor in the equivalent CM circuit is selected to damp the CM current resonance for simplification and damping performance. Different from the implementation in CPWM where a pair of small voltage vectors exist and are used to adjust the CM voltage directly, the proposed method for DPWM application is implemented indirectly by adding the CM adjustment quantity to differential-mode (DM) control quantity with appropriate coefficients. Depending on the sector of DM control quantity in the α β reference frame, the coefficients are calculated using one of three specific voltage vectors. Experimental results are given to demonstrate the effectiveness of theoretical analyses and the proposed method.

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Space vector modulation with reduced common mode voltage for six-phase drives

COMPEL The International Journal for Computation and Mathematics in Electrical and Electronic Engineering ◽

10.1108/compel-09-2019-0347 ◽

2020 ◽

Vol 39 (2) ◽

pp. 395-411

Author(s):

Mohammad Jafar Zandzadeh ◽

Mohsen Saniei ◽

Reza Kianinezhad

Keyword(s):

Pulse Width ◽

Pulse Width Modulation ◽

Torque Ripple ◽

Drive System ◽

Limiting Factors ◽

Space Vector ◽

Common Mode ◽

Content Type ◽

Common Mode Voltage ◽

Space Vectors

Purpose This paper aims to present a modified space vector pulse width modulation (SVPWM) technique for six-phase induction motor drive based on common-mode voltage (CMV) and current losses which are two important issues affecting drive system behavior and quality. Design/methodology/approach It is shown that the presence of z-component currents and the presence of CMV in six-phase drive system are two major limiting factors in space vector selection. The behavior of several space vector selections in a two-level inverter considering minimum CMV and z-components is investigated. Then, the space vectors in a three-level inverter is analyzed and tried to explore an SVM technique with better behavior. Findings The analyses show that all the problems cannot be solved in a six-phase drive system with two-level inverter despite having 64 space vectors; this study tried to overcome the limitations by exploring space vectors in a three-level inverter. Originality/value The proposed pulse width modulation (PWM) strategy leads to minimum current distortion and undesired current components with zero CMV and modest torque ripple.

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Evaluation of Carrier-Based Modulation Techniques With Common-Mode Voltage Reduction for Neutral Point Clamped Converter

IEEE Transactions on Power Electronics ◽

10.1109/tpel.2017.2707583 ◽

2018 ◽

Vol 33 (4) ◽

pp. 3268-3275 ◽

Cited By ~ 8

Author(s):

Meng-Jiang Tsai ◽

Hsin-Chih Chen ◽

Meng-Ru Tsai ◽

Yao-Bang Wang ◽

Po-Tai Cheng

Keyword(s):

Neutral Point ◽

Common Mode ◽

Common Mode Voltage ◽

Modulation Techniques ◽

Clamped Converter

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A Five-Level Converter in a Three-Level Mode for Common-Mode Leakage Current Suppression in PV-Generation Systems

10.20944/preprints202107.0304.v1 ◽

2021 ◽

Author(s):

Aleksey Vyacheslavovich Udovichenko ◽

Sergey Viktorovich Brovanov ◽

Evgeny Valerievich Grishanov ◽

Svetlana Mikhailovna Stennikova

Keyword(s):

Leakage Current ◽

Pulse Width ◽

Pulse Width Modulation ◽

Renewable Energy Sources ◽

Multilevel Converter ◽

Generation System ◽

Common Mode ◽

Common Mode Voltage ◽

Conducting Research ◽

Pv Generation

Power generation systems based on renewable energy sources are finding ever-widening applications and many researchers work on this problem. Many papers address the problem of transformerless structures, but few of them are aimed at conducting research on structures with multilevel converter topologies. In this paper a grid-tied transformerless PV-generation system based on a multilevel converter is discussed. There are common-mode leakage currents which act as a parasitic factor. It is also known that common-mode voltage is the main cause of the common-mode leakage current in grid-tied PV-generation systems. This paper considers the space vector pulse-width modulation (PWM) technique which is used to suppress or reduce common-mode leakage current. The proposed engineering solutions for a generation system based on the multilevel converter controlled with a pulse-width modulation technique are verified by experiment.

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Common Mode Voltage Elimination for Quasi-Switch Boost T-Type Inverter Based on SVM Technique

Electronics ◽

10.3390/electronics9010076 ◽

2020 ◽

Vol 9 (1) ◽

pp. 76 ◽

Cited By ~ 4

Author(s):

Duc-Tri Do ◽

Minh-Khai Nguyen ◽

Van-Thuyen Ngo ◽

Thanh-Hai Quach ◽

Vinh-Thanh Tran

Keyword(s):

Pulse Width ◽

Pulse Width Modulation ◽

Space Vector Modulation ◽

Common Mode ◽

Switching Sequence ◽

Modulation Technique ◽

Common Mode Voltage ◽

Vector Modulation ◽

Zero Vector ◽

Current Ripple

In this paper, the effect of common-mode voltage generated in the three-level quasi-switched boost T-type inverter is minimized by applying the proposed space-vector modulation technique, which uses only medium vectors and zero vector to synthesize the reference vector. The switching sequence is selected smoothly for inserting the shoot-through state for the inverter branch. The shoot-through vector is added within the zero vector in order to not affect the active vectors as well as the output voltage. In addition, the shoot-through control signal of active switches of the impedance network is generated to ensure that its phase is shifted 90 degrees compared to shoot through the signal of the inverter leg, which provides an improvement in reducing the inductor current ripple and enhancing the voltage gain. The effectiveness of the proposed method is verified through simulation and experimental results. In addition, the superiority of the proposed scheme is demonstrated by comparing it to the conventional pulse-width modulation technique.

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