TUTCRIS Research Portal

Voltage and current imbalance have adverse impacts on power systems such as
power loss increase, communication interference, and component lifetime
reduction. This paper attempts to look at unbalance impacts from distribution
system operator's (DSO) viewpoint in order to understand them and then mit-
igate the impacts. Since solving the unbalance conditions is influenced by the
way the imbalance is defined, standard unbalance indexes are studied, and
new indexes are proposed in this paper. Re‐phasing of the customers is selected
to reduce the level of unbalance in distribution feeders. Due to the huge num-
ber of customers, a wide variety of choices can be selected for re‐phasing of cus-
tomers, which makes the solution questionable. Therefore, discrete genetic
algorithm (DGA) as a metaheuristic method has been utilized in order to dis-
tribute customers among the network phases optimally considering the fact
that DSO has a limitation for the re‐phasing practice. The aim is to reduce
the unbalance indexes and power losses throughout the network. Simulations
have been carried out on a real test case network, which shows the importance
of load balancing and its effects on the power losses, voltage profile, and cur-
rent flow in that network. The effectiveness of the proposed indexes has also
been demonstrated for the four‐wire multigrounded distribution system. Since
re‐phasing of the majority of customers in distribution networks seems imprac-
tical, a re‐phasing limitation is also investigated in this paper, and some prac-
tical suggestions of optimal load balancing in a real‐world low‐voltage
distribution system have been presented here. Results show the importance
of load balancing in power loss reduction and voltage unbalance improvement in the low‐voltage four‐wire multigrounded distribution system. They also
illustrate that by changing phases of a few customers, power losses and unbal-
ance indexes will be improved significantly.