What is Single Phase, Three Phase Electricity

In order to let everyone know clearly, Dingbo Power, a professional generator manufacturer, will take you to know what single-phase electricity, two-phase electricity and three-phase electricity are.

Difference between single-phase, two-phase and three-phase electricity

The single-phase voltage is 220V, which is used for the life of ordinary residents, and the voltage between the phase line and the neutral line. The two phases are A and B or C of the phase line, and the phase voltage between them is 380V. The common electrical appliance is a 380V electric welding machine. Three phase refers to the 380V phase to phase voltage between A, B and C, and the consumer is a three-phase 380V motor or equipment. A rectifier changes alternating current into direct current.

Motor capacitance cannot replace exciter. Exciter is a kind of motor with carbon brush adjustable speed, which can rotate only when the stator coil and rotor coil are powered at the same time.

Two phase electricity only exists in single-phase motors. It is formed by splitting a single phase into two windings. For example, if one winding is not connected with a capacitor and the other winding is connected with a capacitor, the phase difference between the currents of the two windings is 90 °, which will generate a rotating magnetic field to make the motor work. The same single-phase power is supplied to the motor, with only one live wire and no two live wires.

Three phase electricity is used in industrial production, mainly as the power supply of the motor, that is, the load that needs to be rotated. The generator that can produce the electric potential of equal amplitude, equal frequency and 120 ° phase difference is called three-phase generator; The three-phase generator is used as the power supply, which is called three-phase power supply; The circuit powered by three-phase power supply is called three-phase circuit; U. V and W are called three-phase. The voltage between phases is line voltage, and the voltage is 380V; The phase to central line is called two-phase voltage, and the voltage is 220V.

Difference between three-phase power supply and single-phase power supply

The power supply from the generator is three-phase, and each phase and its characteristic point of three-phase power supply can form a single-phase circuit to provide power for users.

According to the regulations, the neutral point of 380V (three-phase) civil power supply should not be grounded at the inlet end. The power supply mode is to form a loop with a live wire and a neutral wire (neutral point lead out). A ground wire is also connected in the single-phase three core power socket, This is to consider the realization of leakage protector function (The working principle of the leakage protector is: if a human body touches the wire end of the power supply, that is, the live wire, or the internal leakage of electrical equipment, then the current flows from the live wire to the ground through the human body or the housing of electrical equipment, but does not flow through the zero wire, the current of the live wire and the zero wire will be different. The leakage protector will trip immediately after detecting the current difference to protect the safety of the human body and electrical equipment. Generally, the current difference is tens of milliamperes.).

If the neutral point of the power supply is directly grounded, the leakage protector will lose its function and cannot protect people and electrical equipment from short circuit.

Connection of three-phase electrical load

It is divided into triangle connection and Y-shaped connection.

The load lead of the triangle connection method is three live wires and one ground wire, the voltage between the three live wires is 380V, and the voltage between any live wire and the ground wire is 220V.

The load leads of the Y-shaped connection method are three live wires, one neutral wire and one ground wire. The voltage between the three live wires is 380V, and the voltage between any live wire and the neutral wire or the ground wire is 220V.

The total power of three-phase electrical appliances is equal to the voltage of each phase multiplied by the current of each phase and then multiplied by 3, that is, the total power=current × Voltage (220V) × 3（W=U × I × 3）.

Through the above introduction, do you know more about single-phase electricity, two-phase electricity and three-phase electricity? If you have other questions, please call Dingbo Power. Dingbo Power has an excellent technical team led by several experts, which can provide one-stop services for the design, supply, commissioning, maintenance and technical support of your diesel generator set.