Query: Loss balancing in three-level voltage source inverters applying active NPC switches

Candidate papers:

abstract: This paper investigates the use of active neutral point clamp switches in a three level NPC voltage source inverter to balance the losses among the semiconductors. Both a control structure and algorithm are proposed which enable a substantially increased output power of the inverter and an improved performance at zero speed.
author_names: Thomas Bruckner

S Bemet
title: Loss balancing in three level voltage source inverters applying active NPC switches
venue: 2001 IEEE 32nd Annual Power Electronics Specialists Conference (IEEE Cat. No.01CH37230)
year: 2001

abstract: Static converters design has to guarantee that in all specific operating conditions the junction temperature of power devices does not exceed admitted limits. The temperature of different components depends on losses distribution and on the number of switches in IGBT modules. This paper investigates the losses balancing in the most popular 3L conversion structures: 3L Stacked Cells, 3L Neutral Point Clamped (NPC) and 3L Active NPC. The 3L Active NPC concepts accomplish a two independent stages conversion which leads to a better equilibration of losses. The 3L Stacked Cells topology was experimentally realized and some results are presented in the paper.
author_names: Dan Floricau

Guillaume Gateau

Elena Floricau

Ioana Popa

Dan Olaru

Sergiu Ivanov
title: LOSSES DISTRIBUTION IN THREE LEVEL VOLTAGE SOURCE INVERTERS
year: 2007

abstract: In this paper, direct torque control (DTC) of five phase induction motor (FPIM) is implemented using three level neutral point clamped (TL NPC) inverter. One of the advantages of three level inverter over two level one for DTC operation is the low torque ripple. Also TL NPC inverter through space vector modulation technique gives low <inline formula><tex math notation="LaTeX" dv/dt$/tex math>/inline formula> transition with better voltage waveform. By applying conventional lookup table for DTC, the TL NPC inverter does not ensures lower <inline formula> <tex math notation="LaTeX"$dv/dt$/tex math>/inline formula> transition. In this paper, a novel switching scheme for DTC of FPIM using TL NPC inverter is proposed that ensures the low <inline formula><tex math notation="LaTeX" dv/dt$ /tex math>/inline formula> transition and balancing of dc link capacitor voltages of TL NPC inverter. To form the lookup table for DTC operation, instead of using voltage vectors directly, virtual vectors (VVs) are utilized. Two switching states are used in one sample time to generate a VV in <inline formula><tex math notation="LaTeX"\alpha \beta$/tex math>/inline formula> plane, which gives zero resultant voltage in <inline formula> <tex math notation="LaTeX" xy$/tex math>/inline formula> plane. The switching strategy ensures low number of transitions to reduce the switching losses. The switching state redundancies are used in a novel way to balance the dc link capacitor voltages without using any additional hardware. The proposed technique to balance the dc link capacitor voltage gives lower switching frequency. The MATLAB/Simulink environment is used for the simulation and the results are validated through experiments.
author_names: Saifullah Payami

Ranjan Kumar Behera

Atif Iqbal
title: DTC of Three Level NPC Inverter Fed Five Phase Induction Motor Drive With Novel Neutral Point Voltage Balancing Scheme
venue: IEEE Transactions on Power Electronics
year: 2018

abstract: In order to control the neutral point voltage of inverter with discontinuous PWM (DPWM) this paper proposed a generalized discontinuous PWM (GDPWM) based neutral point voltage balancing method for three level neutral point clamped (NPC) voltage source inverter (VSI) Firstly, a triangle carrier based (TCB GDPWM) is proposed. Secondly, the affection on neutral point voltage for the modulation wave are analyzed. Base on the analysis, a bang bang control is adept to control the neutral point voltage via changing the polarity of the certain part of the common mode voltage (CMV) Finally, the proposed method is verified by simulation and experiment. The results show that the propose method has good performance at neutral point voltage control and switching losses reduction.
author_names: Kai Li

Min Wei

Chuan Xie

Fujin Deng

Josep M Guerrero

Juan C Vasquez
title: A generalized discontinuous PWM based neutral point voltage balancing method for three level NPC voltage source inverter with switching losses reduction
venue: 2017 IEEE Applied Power Electronics Conference and Exposition (APEC)
year: 2017

abstract: In this paper, a novel space vector pulse width modulation (SVPWM) scheme for reducing the common mode voltage (CMV) in the three phase five level active neutral point clamped (5L ANPC) inverter for the machine drive systems is proposed, where only the 55 selected voltage vectors with low values of CMV instead of all 125 voltage vectors are utilized. This PWM scheme can significantly reduce the common mode voltage without the increase of switching loss and total harmonic distortion (THD) of the output voltages compared with the conventional one. With the 55 voltage vectors only, the inverter can still work in the full range of modulation index (MI) In addition, the DC link capacitor and flying capacitor voltages can also be controlled for balancing. The PSIM simulation results show that the peak value of the CMV is decreased to one twelfth of the DC link voltage.
author_names: Quoc Anh Le

Dong-Choon Lee
title: A novel SVPWM scheme for common mode voltage reduction in five level active NPC inverters
venue: 2015 9th International Conference on Power Electronics and ECCE Asia (ICPE ECCE Asia)
year: 2015

abstract: The combination of new high voltage high power switching devices and multilevel topology is an effective approach to make medium or high voltage and large capacity converters. This paper focused research works on the Integrated Gate Commutated Thyristor (IGCT) based three level active neutral point clamped (ANPC) converter, and investigated four kinds of modulation strategies based on ANPC three level topology: SPWM, PF SPWM, DF SPWM, PFDF SPWM. Aiming at the application of SPWM in 10MVA NPC three level inverter and PFDF SPWM in ANPC medium voltage inverter, the IGCT device loss is analyzed and studied in detail in this paper. Experimental results verify the correctness of the analysis.
author_names: Mei-fan Li

Chunyi Zhu

Chongjian Li

Wei Chang
title: Control Strategy of Loss Balance on the IGCT Based Large Power Three level Active Neutral Point Clamped Converter
venue: 2019 22nd International Conference on Electrical Machines and Systems (ICEMS)
year: 2019

abstract: The three level neutral point clamped voltage source converter (NPC VSC) is widely used in high power medium voltage applications. The unequal loss distribution among the semiconductors is one major disadvantage of this popular topology. This paper studies the loss distribution problem of the NPC VSC and proposes the active NPC VSC to overcome this drawback. The switch states and commutations of the converter are analyzed. A loss balancing scheme is introduced, enabling a substantially increased output power and an improved performance at zero speed, compared to the conventional NPC VSC.
author_names: Thomas Bruckner

Steffen Bernet

Henry Guldner
title: The active NPC converter and its loss balancing control
venue: IEEE Transactions on Industrial Electronics
year: 2005

abstract: An improved space vector PWM (SVPWM) strategy is proposed in this paper to balance the neutral point voltage (NP) and reduce switching loss for three level active neutral point clamped (ANPC) converter. Compared with the traditional SVPWM, the improved SVPWM strategy reduces the number of vectors and the switching frequency per cycle. So the switching losses can be reduced. According to the NP offset, different switching sequences are used to control the NP voltage. Therefore, the voltage on each capacitor can be controlled effectively. This strategy can balance the NP voltage, no matter which Space Vector Diagram (SVD) the reference vector locates in. Lastly, simulation and experimental results are provided to verify the effectiveness of the proposed control strategy.
author_names: Chao Zhang

Cungang Hu

Guanghui Fang

Hua Li

Zhe Qian
title: An improved SVPWM strategy for three level active NPC inverter
venue: 2017 12th IEEE Conference on Industrial Electronics and Applications (ICIEA)
year: 2017

abstract: In this paper is proposed a new balancing three level three dimensional space vector modulation (B3L 3DSVM) strategy which uses a redundant voltage vectors to realize precise control and high performance for a three phase three level four leg neutral point clamped (NPC) inverter based Shunt Active Power Filter (SAPF) for eliminate the source currents harmonics, reduce the magnitude of neutral wire current (eliminate the zero sequence current produced by single phase nonlinear loads) and to compensate the reactive power in the three phase four wire electrical networks. This strategy is proposed in order to gate switching pulses generation, dc bus voltage capacitors balancing (conserve equal voltage of the two dc bus capacitors) and to switching frequency reduced and fixed of inverter switches in same times. A Nonlinear Back Stepping Controllers (NBSC) are used for regulated the dc bus voltage capacitors and the SAPF injected currents to robustness, stabilizing the system and to improve the response and to eliminate the overshoot and undershoot of traditional PI (Proportional Integral) Conventional three level three dimensional space vector modulation (C3L 3DSVM) and B3L 3DSVM are calculated and compared in terms of error between the two dc bus voltage capacitors, SAPF output voltages and THDv, THDi of source currents, magnitude of source neutral wire current, and the reactive power compensation under unbalanced single phase nonlinear loads. The success, robustness, and the effectiveness of the proposed control strategies are demonstrated through simulation using Sim Power Systems and S Function of MATLAB/SIMULINK.
author_names: Ali Chebabhi

Mohammed Karim Fellah

Abdelhalim Kessal

M F Benkhoris
title: A new balancing three level three dimensional space vector modulation strategy for three level neutral point clamped four leg inverter based shunt active power filter controlling by nonlinear back stepping controllers.
venue: ISA transactions
year: 2016

abstract: This paper proposes a high performance grid connected Photovoltaic (PV) system based on a three phase transformerless three level Active Neutral Point Clamped (3L ANPC) inverter. The ANPC is one of the derived topologies from the Neutral Point Clamped (NPC) one, which is widely used for transformerless grid connected PV applications thanks to its inherent advantages such as: reduced voltage stress on its power switches, reduced output current THD, low high efficiency, and loss and heat balancing capability. The 3L ANPC topology has mainly been proposed to overcome the NPC major issue of unbalanced loss and temperature distribution among its power devices. Furthermore, the modulation strategy is a key issue for loss and temperature balancing inside the ANPC topology. In this paper, the 3L ANPC PV inverter is controlled by a Thermal Balancing PWM (ThB PWM) strategy. This strategy allows an efficient balance of the loss and temperature distribution inside the inverter and a reduced total dissipated losses when compared with the conventional PWM strategies. The effectiveness of the proposed grid connected PV system based on a 6.37 kW 3L ANPC inverter controlled by the ThB PWM strategy is proven through simulation tests performed on PSIM simulator.
author_names: Hanen Messaoudi

Afef Bennani Ben Abdelghani

Najiba Mrabet Bellaaj
title: High Performance Three Level ANPC Inverter with Thermal Balancing PWM Strategy for Grid Connected PV System
year: 2018