1. According to the voltage level, there are ultra high voltage power supply, high voltage power supply, low voltage power supply, and safe voltage power supply.
2. According to the power supply system, there are TNS system, TNC system, TN-C-S system, TT system and IT system.
3. According to the form of power supply, there are three-phase four-wire system, three-phase five-wire system, and two-wire --- ground system.
4. According to the shape of the power supply line, there are grid-type power supply, trunk-type power supply, and so on.
5. According to the number of power supply lines, there are dual-loop power supply and single-loop power supply.
Other divisions are AC power, DC power, and so on.