Application of electric motors

The most widely used among various electric motors is AC asynchronous motor (also known as induction motor). It is easy to use, reliable to operate, inexpensive, and structurally sturdy, but has a low power factor and difficult speed regulation. Large capacity and low speed power machines commonly use synchronous motors (see synchronous motors). Synchronous motors not only have a high power factor, but their speed is independent of the load size and only depends on the grid frequency. Work is relatively stable. DC motors are commonly used in situations where wide range speed regulation is required. But it has a commutator, which is complex in structure, expensive in price, difficult to maintain, and not suitable for harsh environments. After the 1970s, with the development of power electronics technology, the speed control technology of AC motors has gradually matured, and equipment prices have been decreasing, which has begun to be applied. The maximum output mechanical power that a motor can withstand under the specified operating system (continuous, short-term, intermittent cycle) without causing overheating of the motor is called its rated power. When using it, attention should be paid to the regulations on the nameplate. When the motor is running, attention should be paid to matching its load characteristics with the characteristics of the motor to avoid speeding or stalling. Electric motors can provide a wide range of power, from milliwatts to tens of thousands of kilowatts. The use and control of electric motors are very convenient, with the ability to self start, accelerate, brake, reverse, and hold. The output power of a general electric motor varies with the speed during speed regulation.