High voltage motor refers to a motor with a rated voltage of over 1000V. The commonly used voltages are 6000V and 10000V, and due to differences in foreign power grids, there are also voltage levels of 3300V and 6600V. The generation of high-voltage motors is due to the direct ratio of motor power to the product of voltage and current. Therefore, when the power of low-voltage motors increases to a certain extent (such as 300KW/380V), the current is limited by the allowable bearing capacity of the wires, making it difficult to increase, or the cost is too high. It is necessary to achieve high-power output by increasing the voltage. The advantages of high-voltage motors are high power and strong impact resistance; The disadvantage is high inertia, making it difficult to start and brake.

High voltage motors are divided into: high voltage synchronous motors; High voltage asynchronous motor; High voltage asynchronous wound motor; High voltage squirrel cage motors, etc.

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, meeting various operational requirements; The working efficiency of the electric motor is high, and there is no smoke or odor, which does not pollute the environment, and the noise is also low. Due to its series of advantages, it is widely used in various fields such as industrial and agricultural production, transportation, national defense, commercial and household appliances, medical electrical equipment, etc. The output power of a general electric motor varies with the speed during speed regulation.