'Meters' are intended as diagnostic instruments. They allow displaying signals in alternative representations, both in SI-units or in 'pu'.
Use them only when and where needed. Otherwise use 'Sensors'.
Output variables:
p {AC active, AC reactive, DC} power term_p to term_n
Optional output variables:
p_av power term_p to term_n, time tau average of p
Comment on the sign-definition of reactive power see ACdq0.Sensors.