Concerning “Instantaneous Power Compensation in Three-Phase Systems by Using $phbox-qhbox-r$ Theory”

In the paper by Kim et al. (see ibid., vol.17, p.701-10, Sept. 2002), a new representation of instantaneously defined voltages, currents and powers was proposed which is based on transforming the original a-b-c quantities into a p-q-r coordinate system. If the compensating currents are determined really instantaneously, that means without preprocessing or filtering, then the results of the p-q-r theory are identical as well to those of the original p-q theory as to the results of the FBD-method. The calculation effort needed by the p-q-r theory is the highest, that of the FBD-method by far the lowest.