Conductor resistance changes with changing conductor temperatures

which shows that power flow is influenced by environmental factors. In consideration of the relationship between line temperature

line resistance and power flow

this paper presents a power flow formulation for distribution network with the electrothermal coupling effect taken into account. In the formulation

line resistance is a variable rather than a constant as is usual with the traditional power flow method. An extended power flow calculation for distribution system based on the normal backward/forward sweep power flow algorithm is proposed to address the computational complexity of the formulation

in which the line thermal balance equation is embedded in the forward sweep

as well as the line temperature

line resistance and power flow are dynamically updated during the process of iteration. Consequently

the power flow calculation for distribution network considering the electrothermal coupling effect is realized briefly and efficiently. Two case studies using an IEEE 14-bus distribution network and a 118-bus distribution network show that the electrothermal coupling effect has a profound impact on the power flow

while power flow calculation based on constant resistance may lead to significant errors.