Standard power conversion topologies are built around the concept of commutation cell using semiconductors
operating in 'SwitchMode' to regulate the energy flowing between a voltage source connected to the High Voltage side
of the commutation cell and a current source connected on the Low Voltage side of the commutation cell.
Such commutation cells operate in two configurations ( full transfer of energy from one source to the other,or zero transfer of energy)
and the duty cycle of utilization of these two configurations defines the average energy flowing between the two sources.
In recent years, several multicell conversion topologies have been introduced.
These topologies use macro-commutation cells composed of several commutation cells connected in series and parallel,
and internal passive components to allow more configurations and more degrees of freedom in the control of the energy flow.
Such macro-commutation cells can be used to replace the conventional commutation cell of any standard converter.
A consequence of the increased number of configurations is the creation of multilevel current or voltage chopped waveforms
on respectively the High Voltage and the Low Voltage sides of the macro-commutation cell.
These principles can be combined to take advantage of both series and parallel connection of commutation cells
and to improve the waveforms on both sides of sophisticated macro-commutation cell.
These topologies may seem complicated at first sight, but they can be easily understood by means of a systematic use of the concept of commutation cell.
Also, it can be shown that these circuits can be studied, designed and simulated more easily using design masks and vectorization:
Design masks are simple lines of codes that can be associated to a circuit or subsystem to derive simulation parameters from the specifications of a converter
(for example derive the value of the smoothing inductor of a buck converter from the input voltage, the switching frequency and a specified current ripple,
or implement a full design process for second order filter of series-parallel multicell converter, )
Vectorization of components means that the component represented in a circuit can represent a vector of components,
the size of the vector (the number of components) being a variable.
When the circuit is built the appropriate way, this concept allows describing two-level
and multilevel converters with the same circuit to check and compare very easily the performances
obtained with different design options.