It USES a current-carrying coil (or

It USES a current-carrying coil (or stator winding) to generate a rotating magnetic field, which ACTS on the rotor (such as a closed aluminum frame squirrel cage) to form the magnetoelectric potential of the rotating moment. According to the different power supply, it can be divided into DC motor and AC motor. Most motors in a power system are ac motors, whether synchronous or asynchronous (the speed of the stator's magnetic field is out of sync with the speed of the motor's rotor). The motor is mainly composed of stator and rotor. A motor works by applying a magnetic field to an electric current to make it spin.(1) The starting mode of the motor includes:1. Direct start at full pressure:When grid capacity and load side allow full voltage direct starting, full voltage direct starting can be considered. Mainly used for starting small power motor. From the point of view of energy saving, this method is not suitable for motors with more than 11kW.2. Start of autotransformer:The auto-transformer can adopt multi-tap step-down, which can not only meet the starting needs of different work loads, but also obtain larger starting torque, which is a common torque in the starting of large-capacity motors. When the winding tap is 80%, the starting torque can reach 64% of the direct starting torque. Starting torque can be adjusted by tapping. It is still widely used.3. Star Triangle startup:For the normal operation of the triangle winding squirrel-cage asynchronous motor, the stator winding is connected to the star winding when starting, and the stator winding is connected to the triangle winding after starting, which can reduce the starting current and its influence on the power grid. This is called star Triangle decompression boot, or star triangle boot. When star connection is used, the starting current in the connection is only 1/3 of the original direct starting current, which is suitable for no-load or light-load starting. It has the simplest results and the cheapest price compared to other startups. Another advantage of star delta starting is that the motor can be star connected when the load is light. At this point, the rated torque can be matched with the load, improve the motor efficiency, save energy consumption.4. Soft starter:It can realize the voltage regulation of the motor and the voltage regulation principle of the thyristor shift starting, and is mainly used for the starting control of the motor. Due to the existence of thyristor elements, the harmonic interference in thyristor operation is very large, which has a certain influence on the power grid. In addition, the fluctuation of the power network can also affect the thyristor conduction, especially when there are more than one thyristor in the same power network. As a result, the failure rate of thyristors is very high, because it involves power electronics technology, so the maintenance technicians are also very high.