Digital Control of Power Converters

Power electronics converters are commonly used in a variety of applications to control and manage the flow of electrical energy . These applications include electric vehicles, electric traction, "more electric" aircraft and microgrids integrating distributed generation based on renewable energy systems (wind, photovoltaic, biomass generators, etc.). In all these applications, converters play a vital role, since they enable electrical energy to be transformed from one form to another, while controlling its direction and characteristics.

The main challenges of modern power electronics converter controls can be summarized as follows:

• efficient management of electrical energy flow and its characteristics (voltage and current waveforms, power factor, harmonic distortion rate (TDH), etc.);

• cost reduction ;

• operating reliability (fault tolerance and continuity of service) ;

• control accuracy (the system responds accurately to reference setpoints) ;

• the possibility of adding auxiliary functions in addition to basic control functions in order to contribute to power grid support .

Responding effectively to these constraints and challenges depends essentially on :

• the algorithmic content implemented ;

• the calculation and integration capabilities of the digital target used;

• the accuracy of the measurements supplied by the power/control interface, particularly in relation to the full scale of the A/D converters used.

Thus, the solution used to implement the algorithm is a key element in guaranteeing the desired control performance. As mentioned above, the majority of solutions used to implement control algorithms are digital, given the advantages they offer (digital immunity to disturbances, flexibility of modification, etc.). Since their introduction to the market in the 1970s,...