Harmonic Power Flow Calculation of Distribution Network With Electric Vehicle Charge Station

The operation voltage of the node where EV (Electric Vehicle) charge station connecting to the network is not at rated voltage level under normal circumstances. The variation of voltage will cause the current value changes under the same power situation. In order to make the calculation more precise, a harmonic power flow calculation model applied to EV charge station is proposed in this paper, which is an equivalent current model by considering the voltage influence and self-impedance of connected-grid side of EV charge station. According to the working principle of EV charge station, a harmonic power flow calculation method that contains EV charge station model is put forward. By taking the IEEE-33 node distribution system as an example, the harmonic power flow is calculated under different situations with 2 kinds of harmonic sources. From the result we can see that voltage distortion rate of panel point and adjacent nodes are increased after the modification of harmonic current. The connection of EV charge station to the network influences the power quality of the panel point and adjacent nodes.