Analysis of DC-Link capacitor losses in three-level neutral point clamped and cascaded H-Bridge voltage source inverters

Orfanoudakis, Georgios I.; Sharkh, Suleiman M.; Yuratich, Michael A.

doi:10.1109/isie.2010.5637820

Cited by 21 publications

(10 citation statements)

References 8 publications

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“…where I rippe C is the RMS of AC current component through the DC-link capacitance; R ERS is the equivalent active series resistance of the DC-link capacitors; R par is the equivalent impedance of the balancing resistors. Let us use the approximated values of the parameters R par = 10 5 and R EMS = 0.1 Ohm as given in references [5,31]. The calculation of the I rippe DC value encounters some difficulties due to the fact that the ripples are caused by both the inverter and the rectifier stages of the converter [32]:…”

Section: Dc-link Lossesmentioning

confidence: 99%

Efficiency Analysis of Low Electric Power Drives Employing Induction and Synchronous Reluctance Motors in Pump Applications

et al. 2019

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Due to the rapid increase in the number of variable speed AC drives, the analysis of their energy efficiency has become highly essential. However, such an analysis requires consideration of a wide variety of factors. This includes considering the energy loss in the frequency converter, depending on the motor type. In this article, a computational comparison of the energy properties of variable frequency pump drive employing two types of electric machines, i.e. an induction and a synchronous reluctance motor, is presented. The effect of the motor type on the losses in a low-voltage two-stage frequency converter using analytical and numerical models, with a further comparison, is investigated. Furthermore, an alternative approach to determine the current magnitude and power factor of the load of the converter is suggested. Eventually, this study provides a quantitative estimate of the increase in losses in the converter caused by using the two different motor types. Several experimental tests are conducted on induction and synchronous 1.1 kW reluctance motors.

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Section: Dc-link Lossesmentioning

confidence: 99%

Efficiency Analysis of Low Electric Power Drives Employing Induction and Synchronous Reluctance Motors in Pump Applications

et al. 2019

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“…An expression for the DC-link capacitor RMS current (I cÀFB ) can be obtained using the expressions for the DC-link RMS and average currents obtained in (11) and 10, respectively, as follows:…”

Section: Single-phase Full-bridge Invertermentioning

confidence: 99%

“…For a threelevel inverter, this expression is more involved as there are three possible connections to the converter mid-point and more devices are involved. More recently, an expression has also been reported for the capacitor RMS current in a sinusoidally modulated three-phase NPC inverter [11,12].…”

Section: Introductionmentioning

confidence: 99%

Analytical evaluation of DC capacitor RMS current and voltage ripple in neutral-point clamped inverters

et al. 2017

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The sizing of the DC-link capacitor in a three-level inverter is based on the RMS current flowing through it. This paper analyses the DC-link capacitor RMS current in a neutral-point clamped (NPC) inverter and expresses the same as a function of modulation index, line-side current amplitude and power factor. Analytical closed-form expressions are derived for the capacitor RMS current for single-phase half-bridge, single-phase full-bridge and three-phase three-leg topologies of a three-level inverter. The worst-case capacitor current stress is determined for each topology based on the analytical expressions. Further, analytical expressions are derived for the RMS values of low-frequency and high-frequency capacitor currents. These expressions are then used to estimate voltage ripple across the DC capacitor for sinusoidally modulated three-phase NPC inverter. The analytical expressions for the RMS current and voltage ripple are validated experimentally over a wide range of operating points. Keywords. Current control; current stress; diode-clamped inverter; full-bridge inverter; half-bridge inverter; multi-level inverter; proportional-resonant controller; sinusoidal modulation; vector control; voltage ripple.

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“…The calculation methods of the auxiliary losses were proposed in [21]- [22]. In order to maximize the efficient performance, the key point of the power devices and auxiliary components should be taken into account as follows.…”

Section: Losses and Efficiency Comparative Analysis Of The Convementioning

confidence: 99%

A High Efficiency Two-stage Inverter for Photovoltaic Grid-connected Generation Systems

Liu¹,

Song²,

Shen³

2017

Journal of Power Electronics

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Conventional boost-full-bridge and boost-hybrid-bridge two-stage inverters are widely applied in order to adapt to the wide dc input voltage range of photovoltaic arrays. However, the efficiency of the conventional topology is not fully optimized because additional switching losses are generated in the voltage conversion so that the input voltage rises and then falls. Moreover, the electrolytic capacitors in a dc-link lead to a larger volume combined with increases in both weight and cost. This paper proposes a higher efficiency inverter with time-sharing synchronous modulation. The energy transmission paths, wheeling branches and switching losses for the high-frequency switches are optimized so that the overall efficiency is greatly improved. In this paper, a contrastive analysis of the component losses for the conventional and proposed inverter topologies is carried out in MATLAB. Finally, the high-efficiency under different switching frequencies and different input voltages is verified by a 3 kW prototype.

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Analysis of DC-Link capacitor losses in three-level neutral point clamped and cascaded H-Bridge voltage source inverters

Cited by 21 publications

References 8 publications

Efficiency Analysis of Low Electric Power Drives Employing Induction and Synchronous Reluctance Motors in Pump Applications

Efficiency Analysis of Low Electric Power Drives Employing Induction and Synchronous Reluctance Motors in Pump Applications

Analytical evaluation of DC capacitor RMS current and voltage ripple in neutral-point clamped inverters

A High Efficiency Two-stage Inverter for Photovoltaic Grid-connected Generation Systems

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