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Author to whom correspondence should be addressed. Neutral-point-clamped multilevel converters are currently a suitable solution for a wide range of applications. It is well known that the capacitor voltage balance is a major issue for this topology.
This study deals with a new control strategy for flying capacitor (FC) based multilevel converter, in order to attain the desired reference value for five-level output voltage in active neutral point clamped (ANPC) converter. The balancing of capacitor voltages is one of the crucial aspects of grid-tied photovoltaic (PV) fed ANPC converter.
In the most typical case, the operation of the NPC converter is not allowed if the DC capacitor voltages are unbalanced. Therefore, some actions should be included in the switching strategy and/or control of the NPC converter to achieve the required DC capacitor voltage balance.
The capacitor voltages of NPC leg, V c1 and V c2 are balanced to half of DC link voltage. The capacitor of DC link charges and discharges and can be observed in capacitor voltage waveforms of DC link. The flying capacitor voltage is balanced to V dc /4. Fig. 3b shows MATLAB/Simulink results in dynamic conditions.
• Operation of NPC multilevel converters under DC-link capacitor voltage unbalance is feasible. • This feature can be used to improve the system performance in some applications. + Independent control of the voltage of each photovoltaic array.
The neutral-point piloted converter, alternatively known as T-type converter, produces three output voltage levels by connecting the DC neutral to midpoint of phase leg through bidirectional switches.
It is well known that the capacitor voltage balance is a major issue for this topology. In this paper, a brief summary of the basic topologies, modulations, and features of neutral-point-clamped multilevel converters is …
The topology of three-level inverters can be divided into three categories: cascade H-bridge (CHB) [4], flying capacitor (FC) [5], and neutral-point-clamped (NPC) [6].
the neutral-point-clamped (NPC) converter family, one of the three basic multilevel converter families (NPC, flying capacitor, and cascaded H-bridge) (3), were originally pre-sented (4–9). …
This paper presents methods for voltage balancing of capacitors, capacitance monitoring and open-circuit fault detection in nested neutral point-clamped (NNPC) converter …
This study deals with a new control strategy for flying capacitor (FC) based multilevel converter, in order to attain the desired reference value for five-level output voltage …
1 Introduction. Since 1980s, neutral-point clamped (NPC) three-level inverters have been widely used in medium and high voltage, high power applications, for their …
This study investigates capacitor sizing for three-level neutral-point-clamped and cascaded H-bridge inverters, based on an analysis of dc-link capacitor current. Methods used to derive expressions for the root-mean …
Neutral inversion, Neutral shift or Neutral voltage displacement is the phenomenon in which the imaginary neutral of an ungrounded system falls outside the voltage triangle. For a perfectly balanced ungrounded system, the …
Abstract: Dc-link capacitor sizing is a critical aspect of inverter design. This study investigates capacitor sizing for three-level neutral-point-clamped and cascaded H-bridge inverters, based …
In this paper, a pulsewidth-modulation (PWM) technique with neutral point capacitor voltage balancing in single-phase neutral-point-clamped converters is presented. …
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 …
Potential energy is always defined relative to some reference position. Unless your circuit is "grounded", you can choose that point (connect the black lead from your …
This study deals with a new control strategy for flying capacitor (FC) based multilevel converter, in order to attain the desired reference value for five-level output voltage in active neutral point...
This paper presents methods for voltage balancing of capacitors, capacitance monitoring and open-circuit fault detection in nested neutral point-clamped (NNPC) converter …
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 …
It is well known that the capacitor voltage balance is a major issue for this topology. In this paper, a brief summary of the basic topologies, modulations, and features of …
Fig 2 shows the proposed neutral-point diode-clamped rectifier to draw a sinusoidal line current with low harmonic content and high power factor. the circuit configuration consists of one …
1 Introduction. Single-phase three-level neutral-point-clamped (NPC) converters have been widely used as the grid-side converter to interface with electricity grid in the AC …
switches is on. The output is returned to the mid-point of two series capacitors, which provides the 0 V neutral point. In applications like PV, ESS VDC is usually higher than 400 V. Therefore, …
In this paper, a simplified control technique is proposed to control capacitor voltages of three-phase Neutral-Point Clamped bi-directional rectifier based on the modified …
The balancing circuit is composed by one or two multilevel neutral-point clamped legs, an inductor and eventually a capacitor. Suitable modulation strategies to control the balancing are defined …
The neutral-point piloted converter, alternatively known as T-type converter, produces three output voltage levels by connecting the DC neutral to midpoint of phase leg through …