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Motor Industry: A Comprehensive Guide to High Voltage AC Motors

Honest| 2024-03-01|Return

High-voltage AC motors are AC motors that operate on alternating current and are designed for use typically above 1,000 volts or higher, and primarily used in electric and hybrid vehicles to power the vehicle.


High-voltage AC motors can be divided into induction, synchronous, and variable frequency motors.

A. Induction Motor

Induction motors are also called asynchronous motors, and their working principle is based on electromagnetic induction. In these motors, the current required by the rotor to produce torque is obtained by electromagnetic induction from the magnetic field of the stator winding. It means the rotor is not directly electrically connected to the power source. Induction motors can run at a constant speed under varying loads.


B. Synchronous Motor

The operation of a synchronous motor is synchronized with the frequency of the supply current; that is, the rotation period of the motor is exactly equal to an integer multiple of the AC period. Synchronous motors can run at constant speed under full load. They can be further divided into brushless and brushed motors based on whether brushes are used for commutation.

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C. Variable Frequency Motor

A variable frequency motor is a high-voltage motor that adopts variable frequency technology for speed regulation. It adjusts the motor speed by changing the power frequency, thereby achieving high efficiency, energy saving, and precise control.


The Structure of High Voltage AC Motor

It mainly consists of stator, rotor, shell, and bearings.


A. Stator: it is the stationary part of the motor, and mainly includes the stator core stator winding, and other components;

a. Stator Core: It usually consists of a series of laminated silicon steel sheets. The silicon steel sheets are insulated to reduce eddy current losses. The main function of the stator core is to generate a rotating magnetic field.

b. Stator Winding: it is located in the slot of the stator core, and is powered by AC power to generate a rotating magnetic field. The design of the stator winding depends on the rated voltage and frequency of the motor.


B. Rotor: It is the rotating part of the motor, and mainly includes the rotor core rotor winding, and other components;

a. Rotor Core: It similar to the stator core, the rotor core is also made of multiple layers of silicon steel sheets stacked to minimize losses;

b. Rotor Winding: In an asynchronous motor, the rotor winding may be cage type or wire wound type. In a synchronous motor, the rotor winding is powered by DC to produce a constant magnetic field.


C. Shell

The shell provides structural support, protects internal components, and also dissipates heat. It is usually made of cast iron or steel and can withstand harsh working environments.


D. Bearing

The bearings support the rotor, allowing it to rotate within the stator while reducing friction. Common bearing types include sliding bearings and rolling bearings.

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The Working Principle of High Voltage AC Motor


When the AC power supply is connected to the motor, AC flows through the stator winding, generating an alternating magnetic field. The magnetic field passes through the rotor core and induces an induced electromotive force in the rotor winding, thereby generating an induced current. The induced current interacts with the magnetic field in the rotor core to produce electromagnetic torque, causing the rotor to rotate.


The Characteristics of High Voltage Current Motors


A. Efficiency: Compared with low-voltage motors, high-voltage AC motors are generally more efficient because high-voltage motors can produce the same power at lower currents, thereby reducing energy loss and increasing the vehicle’s cruising range;

B. High Power Density: The power density of high-voltage AC motors is greater than that of low-voltage AC motors, which can reduce the size and weight of the motors;

C. Fast Torque Response: The high-voltage AC motor has a fast torque response, which can improve the acceleration performance of the vehicle.

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The Challenges Faced by High Voltage AC Motors:


A. Safety: High-voltage AC motors have high-voltage safety risks, and corresponding safety measures need to be taken;

B. Cost: The cost of high voltage AC motors is higher than that of low-voltage AC motors;

C. Complexity: The control system of high-voltage AC motors is more complex than that of low-voltage AC motors;

D. Noise: High-voltage AC motors must be designed with efficiency, reliability, and safety in mind to meet the needs of various applications.


If you need equipment to produce high-voltage AC motors, please feel free to contact us. HONEST HLS has been deeply involved in intelligent motor equipment solutions for 17 years. And we believe that we can provide you with services that satisfy you. 


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