A multi-level converter (MLC) is a method of generating high-voltage wave-forms from lower-voltage components. MLC origins go back over a hundred years, when in the 1880s, the advantages of DC long-distance transmission became evident.
Modular multi-level converters (MMC) were investigated by Tricoli et al in 2017. Although their viability for electric vehicles (EV) was established, suitable low-cost semiconductors to make this topology competitive are not currently available (as of 2019).
In 1999, Tolbert described the use of MLC for battery operated electric motors.
Habib's 2018 review paper reviews multi-level inverters (a synonym for MLC) stating the advantages of bi-directional energy flows to power the motor or charge the battery system.
High voltage DC converters
HVDC converter An HVDC converter converts electric power from high voltage alternating current (AC) to high-voltage direct current (HVDC), or vice versa. HVDC is used as an alternative to AC for transmitting electrical energy over long distances or between AC powe ...
s typically use series connected switched capacitors blocks. The blocks are switched in or out of the circuit to form the desired waveform, typically
three phase AC.
Low voltage DC converters
Hydrogen generation via
electrolysis
In chemistry and manufacturing, electrolysis is a technique that uses direct electric current (DC) to drive an otherwise non-spontaneous chemical reaction. Electrolysis is commercially important as a stage in the separation of elements from n ...
requires DC currents over several thousand amperes, but DC voltages in the range of only 100...400 VDC. A high voltage modular multi-level converter (MMC) can be adapted by connecting a galvanically isolated LLC
Resonant converter A resonant converter is a type of electric power converter that contains a network of inductors and capacitors called a "resonant tank", tuned to resonate at a specific frequency. They find applications in electronics, in integrated circuits.
The ...
to each module capacitor. Several half-bridge and
full-bridge based MMC topologies are evaluated in.
Such a converter can also be used to provide a centralized 400V DC power supply for
data centers
A data center (American English) or data centre (British English)See spelling differences. is a building, a dedicated space within a building, or a group of buildings used to house computer systems and associated components, such as telecommunic ...
.
M2LeC
M
2LeC (pronounced Emlek), is a form of multi-level converter that combines the functions of generating electric motor wave-forms, with battery charging and management in a single set of power electronics hardware, where the various functions are performed through software alone.
References
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Voltage
Electrical components