Electric powers that fulfill Tellegen’s theorem and those that do not: Analysis of consequences

Several electric powers were defined during the last century with the intention of being useful in electrical power systems, sometimes without considering other physical properties. For this reason, a few of these powers may seem limited to specific purposes and distant from the general physical theory of power. This paper investigates which of these electrical powers satisfy the most important property of physical power, which is the property derived from the energy conservation law. The paper also shows the usefulness this property confers to the electric powers that possess it and how it is possible to give those powers broader definitions. Particularly, the power definitions for single and three-phase systems can be extended to any multi-terminal network providing those powers satisfy the energy conservation law. On the contrary, this generalization is not possible for those powers that do not meet the conservation law, and, what is more, some general concepts become confusing when applied to these powers.

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► We show some electrical powers do not fulfill Tellegen’s theorem.
► Those powers have shocking properties not expected from a power.
► For example, isolated networks may absorb power, even though nothing delivers it.
► The power absorbed by a group of branches may not be the sum of each branch’s power.
► Power compensation techniques are not valid for these powers.