Hello, friends welcome to the new post. In this post, we will have a detailed look at Introduction to Hysteresis Motor. The hysteresis motor is a type of synchronous motor that does not need any separate excitation sources like a synchronous motor. It can function at a single as well as three-phase power source. The torque generation in this motor caused due to the revolving flux induced in the rotor through a flux of the stator.
In this post we will discuss its working structure and some other parameters. So let’s get started with Introduction to Hysteresis Motor.
Introduction to Hysteresis Motor
- Hysteresis motor belongs to the family of special-purpose motors that uses the hysteresis process to generate torque.
- The rotor structure of this motor is the cylindrical shape created with a magnetic substance with the absence of teeth, and windings,.
- The stator of can be designed to operate for single and three-phase if it is single-phase designed then there is a need of a permanent capacitor to link with the auxiliary windings. In a result, it generates a smooth field that caused to reduce motor losses.
- The below figure indicates the working of the hysteresis motor.
- If three or single phase is connected to the motor current is given to the stator of the motor rotating field exists in the motor.
- This field does magnetization of the metallic portion of the rotor and creates magnet poles.
- If the motor rotating speed is less than synchronous speed then 2 sources of torque exist in it.
- Most of the torque is generated due to the hysteresis. In case the field of the stator touches the surface of the rotor then rotor flux does not follow this path since the metallic part of the rotor has larger hysteresis losses.
- The larger the value of intrinsic hysteresis losses at the rotor the larger the angle through which the rotor field lags behind the stator field.
- As the rotor and stator field have different angles than the finite value of torque induced in the motor.
- With that stator field will generate eddy currents in the rotor and these eddy current generates a field in results that further rises he torque in the rotor.
- The larger the relative speed among the rotor and stator field the larger the eddy current and eddy current torques.
- When the motor speed becomes the synchronous speed the stator flux stops to touch the rotor and the rotor behaves like a permanent magnet.
- The torque induced in the motor is proportional in relation to the angle between the rotor and stator field to the extreme angle adjusted by the hysteresis in the rotor.
- The torque-speed characteristic of the hysteresis motor can see n here.
- As the quantity of hysteresis in a certain rotor is a function of stator flux density and the material through which it is created. The hysteresis torque of the motor is the almost constant value at any speed from 0 to synchronous speed.
- The eddy current torque almost has a proportional relation to the slip of the motor.
- these 2 factors apply in sum for the shape of the hysteresis motor torque-speed characteristic.
- As the torque of the hysteresis motor for synchronous speed is larger than its extreme synchronous torque the hysteresis motor can rotate at any load which it can operate at normal function.
- The very less hysteresis motor can be designed through a shaded pole stator structure configuration to design a less self-starting low-power synchronous motor/
- As a motor, that is shown in the below figure.
- It is generally used as the driving phenomena in electric clocks. The electrical clock is so synchronized to the line frequency of the power network and the resultant clock is as appropriate as the frequency of the power system that is linked to it.
Applications of Hysteresis Motor
- The main applications of hysteresis motor are explained here/
- It used in the electrical clock.
- It used in reading players.
- Used in teleprinters
- It used in time-related devices.
Faqs
What are the working principles of hysteresis motor?
- The hysteresis motor is a single-phase synchronous motor and works based on the effect of magnetic hysteresis. The magentic hysteresis defines that magnetic flux density for ferromagnetic materials lags magnetizing force.
What are the different types of hysteresis motors?
- Cylindrical hysteresis motors.
- Disk hysteresis motors.
- Circumferential-Field hysteresis motor.
- Axial-Field hysteresis motor.
What are the advantages of a hysteresis motor?
- The hysteresis motor generates output torque with the use of the magentic material hysteresis effect and has the main benefits that easy to construct, has high-speed working, high-temperature resistance, and self-starting features.
Is a hysteresis motor AC or DC?
- The hysteresis motor is an AC motor of a rotating magnetic field. It rotates at a constant speed relevant of the frequency of the AC supply. So known as a synchronous motor.
What are the characteristics of the hysteresis motor?
- self-starting
- constant speed
- constant torque
- noiseless operation
- small start-up current
- low cost.
What is the primary disadvantage of a hysteresis motor?
- The basic drawback is that it has specific low output power that restricts use for low-power devices. The output power is about one-quarter of the induction motor with the same dimensions.
What is the construction of hysteresis motors?
- The hysteresis motors come with stators and rotors. The stator of the motor comes with main winding with auxiliary or starting winding. When stator winding gets a single-phase supply it generates a synchronously revolving magnetic field.
What is the rotor of a hysteresis motor?
- It is single-phase synchronous motor having a cylindrical rotor created with ferromagnetic material and does not need any DC excitation. Hysteresis motor has a stator and rotor.
What is hysteresis loss in motor?
- Hysteresis losses energy losses that exits in electrical machines since repeated magnetization and demagnetization of the iron core. Due to AC current flow, the iron core magnetized and demagnetized for every cycle, and during the magnetization of each cycle energy was lost.
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That is detailed about hysteresis motor if you have any further query ask in comments. Thanks for reading have a nice day.