Abstract:
This work evokes the problem of disturbances in the electrical network due in particular to the
harmonic currents injected by the polluting loads, such as the static converters of the power
electronics.This equipment absorbs non-sinusoidal currents, consumes reactive power and
degrades the quality of the electrical energy.Consequently, two-level and multi-level MLI
rectifiers are preventive means that preclude the propagation of harmonic currents in the
networks and contribute to the improvement of the quality of the electrical energy. Providing
users with sinusoidal source currents and almost unitary power factor, besides the work in
medium and high voltage networks offered by these multi-level MLI converters through their
topology.
The performance of these means is considerably related to the used control techniques,
namely direct current control or direct power control (DPC).
So,there are the active filters of powers, used as curative means for the depollution of the
electrical networks. The latter are only reliable if the strategies for identifying harmonic
currents are effective and the filter control is efficient.These filters with multi-level structure
also contribute effectively to the depollution of the network of medium and high voltage.
As a result, the induction machine controlled by the bay of these two-level and N-level
converters has shown a good behavior with regard to the disturbances created in the
environment of the machine, such as thereduction in the amplitude of the motor torque
oscillations and the sinusoidal shape of the source currents with virtually zero phase shift.
