Abstract: Many cables per phase were used for low voltage side of energy storage converter, and they were laid in a small layer of container. Many cables laying in a small space, thus the temperature may be very high. Taking a typical energy storage unit of a project as an example, under the condition that current on AC side of energy storage unit remain unchanged, the impact of cable laying mode on the temperature was studied and tested. The results showed that, for a reasonable current carrying capacity, swapping order could provide an even magnetic field and decrease the difference of impedance, and suppress the eddy current loss of container layer. Set a proper space between cables would increase the natural convection heat dissipation and control the temperature.