Single-phase power supply, usually refers to any phase wire (commonly known as live wire) + neutral wire in the 380V three-phase four-wire AC power supply, the voltage is 220V, the phase wire will emit light when measured with an ordinary low-voltage electric pen, and the neutral wire will not emit light. The most common energy source in life.
Single-phase is any one of the three-phase lines to the neutral line. Often called "fire line", "zero line". Usually refers to 220V, 50Hz AC. Single-phase voltage is also called "phase voltage" in electrical engineering.
A three-phase power supply is a power supply composed of three AC potentials with the same frequency, the same amplitude, and a phase difference of 120 degrees.
It is produced by a three-phase alternator. The single-phase alternating current used in daily life is actually provided by one phase of the three-phase alternating current, and the single-phase alternating current power generated by the single-phase generator is now rarely used.
Three-phase alternating current has many advantages over single-phase alternating current. It has obvious advantages in power generation, transmission and distribution, and conversion of electrical energy into mechanical energy. For example, the manufacture of three-phase generators and transformers saves materials compared with the manufacture of single-phase generators and transformers with the same capacity, and the structure is simple and the performance is excellent. Compared with the single-phase transmission line, the three-phase transmission line can save 25% of non-ferrous metals, and the power loss is less than that of the single-phase transmission. Due to the above advantages of three-phase alternating current, it has been widely used.