Switched-capacitor power supplies: DC voltage ratio, efficiency, ripple, regulation

This paper presents a transformerless step-up multilevel inverter based on a switched-capacitor structure. One of the main contributions of the proposed topology is replacing the separated DC voltage source with capacitors which are charged at predetermined time intervals. Therefore, a high-level staircase voltage waveform can be achieved by discharging some of these capacitors on the load. The other contribution of the proposed structure is to eliminate the magnetic elements which traditionally boost the input DC voltage. In addition, asymmetrical or unequal amounts of capacitor voltages create more voltage levels, which enable voltage level increments without increasing the number of semiconductor devices. This paper introduces a self-balanced boost Switched-Capacitors Multilevel Inverter (SCMLI) which is able to create a nearly sinusoidal voltage waveform with a maximum voltage of up to 45 times that of the input voltage DC source. Higher level output voltage levels are also achievable by extending the circuit topology. After determination of the switching angles and selecting the proper switching states for each level, an offline NLC method is used for modulation, which eases the control implementation. Analysis, simulation and experiments are carried out for a 91-level inverter (45 levels for positive and negative voltages and one for zero voltage) are presented.

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A novel symmetric switched capacitor multilevel inverter using non-isolated power supplies with reduced number of components

Sadhana ◽

10.1007/s12046-020-01357-7 ◽

2020 ◽

Vol 45 (1) ◽

Author(s):

Tapas Roy ◽

Pradip Kumar Sadhu

Keyword(s):

Multilevel Inverter ◽

Power Supplies ◽

Switched Capacitor ◽

Number Of Components

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A New Modular Multilevel Inverter Based on Step-Up Switched-Capacitor Modules

Energies ◽

10.3390/en12030524 ◽

2019 ◽

Vol 12 (3) ◽

pp. 524 ◽

Cited By ~ 7

Author(s):

Aryorad Khodaparast ◽

Erfan Azimi ◽

Ali Azimi ◽

M. Ebrahim Adabi ◽

Jafar Adabi ◽

...

Keyword(s):

Theoretical Investigation ◽

High Efficiency ◽

Harmonic Distortion ◽

Low Frequency ◽

Multilevel Inverter ◽

Voltage Source ◽

Switched Capacitor ◽

Level Control ◽

Dc Voltage ◽

Bipolar Voltage

A new structure of switched capacitor multilevel inverter (SCMLI) capable of voltage boosting and with self-balancing ability is introduced in this article. This advantage is the result of a step by step rise of capacitor voltages in each module, supplied by just one DC voltage source. The proposed topology generates a sinusoidal output waveform with a magnitude several times greater than the input one. Higher output staircase AC voltage is obtained by applying a nearest level control (NLC) modulation technique. The most significant features of this configuration can be mentioned as: fewer semiconductor devices, remarkably low total harmonic distortion (THD), desirable operating under high /low frequency, high efficiency, inherent bipolar voltage production, easy circuit expansion, ease of control and size reduction of the circuit thanks to utilizing neither bulky transformer nor inductor. Moreover, the proposed SCMLI is comprehensively surveyed through theoretical investigation and a comparison of its effectiveness to recent topologies. Eventually, the operating principle of a 25-level prototype of the suggested SCMLI is validated by simulation in the MATLAB SIMULINK environment and experimental results.

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