A positive common line and a negative common line are connected to a power source connector connected to a battery pack. First filters are provided on these two common lines, respectively. The positive common line is branched into a positive front line and a positive rear line. The negative common line is branched into a negative front line and a negative rear line. These two front lines are connected to a front power connector that is connected to a front power control unit. These two rear lines are connected to a rear power connector that is connected to a rear power control unit. It is possible to suppress electromagnetic noise on common lines.