Complex sentence: For powering low voltage circuits, trolley is applied static Converter that converts an input voltage of 550 Volts to 28 volts; low-voltage power circuits are also used two 12-volt batteries.
Split into simpler sentences: For powering low voltage circuits, there is a static converter that converts an input voltage of 550 volts to 28 volts. The low-voltage power circuits use two 12-volt batteries.