Loss Partitioning and Loss Allocation in Three-Phase Radial Distribution Systems With Distributed Generation

Abstract

In this paper, the concepts related to loss partitioning among the phase currents in three-phase distribution systems are revisited in the light of new findings identified by the authors. In particular, the presence of a paradox in the classical loss partitioning approach, based on the use of the phase-by-phase difference between the input and output complex power, is highlighted. The conditions for performing effective loss partitioning without the occurrence of the paradox are thus established. The corresponding results are then used to extend the branch current decomposition loss allocation method for enabling its application to three-phase unbalanced distribution systems with distributed generation. Several numerical examples on a three-phase line with grounded neutral and on the modified IEEE 13-node test system are provided to assist the illustration and discussion of the novel conceptual framework.

Accurate Transmission Loss Allocation Algorithm Based on the Virtual Transaction Strategy: Comparison of Path-integral with Discrete Integral Methods

“…Although active injection power (P i ) is an independent variable, it is not explicitly included in (19). However, once all injection powers (P i s) are determined, the loss sensitivity factor can be calculated uniquely.…”

“…Given a loading factor λ, the marginal loss sensitivity is calculated by (19). The marginal loss sensitivity then becomes a function of λ.…”

“…To consider flexible transactions, this paper uses a transaction ratio matrix. Note that these ) (i Lk  s are the same as those were in (19). All the load distribution factors can be determined in the same manner.…”

“…Most of the proposed conventional theories based on sensitivity analysis cannot deal with the nonlinear aspect of the problem, and the sum of the allocated losses results in twice the loss [4]- [10]. Recently, many studies have been conducted based on various approaches such as circuit theory [11]- [13], game theory [14], integration method [15]- [17], etc [18], [19]. This paper shows that the total transmission loss can be represented by the sum of the bus-wise partial integration calculated by real power injections.…”

“…calculated by substituting the load distribution factors into (19). The load distribution factor can be expressed in the form of ∆P Li / ∆P Gi .…”