Reactive power compensation capabilities as a function of parasitic components in three-phase AC/DC voltage and current source rectifiers

AC/DC PWM converters are capable of either supplying or absorbing reactive power while supplying real power to a given load. The operating region is a graphical representation of the range of reactive and active power that these topologies can handle. This paper shows the dependence of the operating region as a function of the parasitic components of the system. Particularly, the dependence upon parasitic resistances of the input filter, which are present in the inductors and capacitors. It is found that the presence of such parasitic components reduces the operating region in voltage source rectifiers, thus, a reduced reactive power compensation range is achieved in practice. The paper shows a systematic mathematical approach to determine how the operating region is modified as a function of such components. Preliminary results show that up to a 20% of the amount of reactive power compensation is lost. Simulated and experimental results confirm the theoretical considerations.