Instantaneous approach to IEEE Std. 1459 power terms and quality indices

• An instantaneous approach to IEEE Std. 1459 is developed.
• Several power magnitudes included in the IEEE Std. 1459 have been redefined.
• New power quality indexes are defined to analyze electrical systems.
• The results confirm overvaluation of power terms when IEEE Std. 1459 is used.
• The instantaneous power approach is adequate for several purposes.

Based on an instantaneous analysis approach to the IEEE Std. 1459, the authors demonstrated in previous works that the effective apparent power should not be calculated including the rms neutral current and the rms line to line voltage terms. The use of these terms drives to expressions of power magnitudes that are overvaluated and disagree with well-accepted definitions. By using the instantaneous approach, new power terms are proposed. Based on these terms, new power quality indices and new expressions of the unbalanced power terms are presented in this paper. An experimental case is used to compare the power magnitudes and power quality indices obtained with both approaches. Results demonstrate than the most significant power terms are over evaluated when IEEE Std. 1459 power definitions are used.