Digital control strategies of DC-DC converters in automotive hybrid powertrains

DC-DC converters are presented in many electric vehicle powertrain systems. This kind of converters is the most basic element of such a powertrain system. Its operation is of vital importance for the proper operation of the whole system. In the context of electric vehicles a wide variety of DC-DC converter topologies have been proposed, but all with something in common: they are digitally regulated by a current control. This chapter explores the digital design of some current control techniques of classic DC-DC converters (boost and buck), which can be part of a much more complex system like the electric vehicle powertrain. The presented digital current techniques can be extended to other more complex DC-DC converter topologies and can also be used as part of even more complex controls, such as a double loop control design, which is also presented in this chapter. Finally, for each of the proposed controls, we give a detailed information, which allows its software-in-the-loop testing. This way, the use of the simplified C block in PSIM allows us to enter a custom C code directly without compiling the code. This advantage allows us to incorporate an external C code, as used in a digital signal controller (DSC), into a simulation model whereby comparison of different proposed digital controls can be easily made. In addition, most simulation programs support C code, such as PLECS, PSIM, MATLAB, and so on. Therefore digital controllers presented in this chapter can be extended to other simulation programs in a simple way.