Synchronous Reluctance motors – Advantages and Disadvantages

Advantages And Disadvantages Of Synchronous Reluctance Motors

What is Synchronous Reluctance motors?

An electromechanical energy conversion mechanism known as a synchronous reluctance motors transforms electrical energy into mechanical energy. 

Due to magnetic locking between the magnetic fields of the rotor and the stator, the motor always operates at synchronous speed.

The Lorentz force law—also known as what happens when the magnetic fields of the stator and rotor interact—is what causes the torque in a DC motor.

However, it adheres to the reluctance concept in synchronous reluctance motors. The rotor experiences constant resistance torque, which drives the motor’s rotation. 

It should be mentioned that switched reluctance motors provide variable reluctance torque as a result of switching circuits.

 A revolving magnetic field is produced at the stator by switching circuits. But since the motor speed won’t be changed in synchronous switching circuits, they are not necessary.

Synchronous reluctance motors operate on the following rule:

“Every time a piece of ferromagnetic material is present in a magnetic field, a force is applied to the material, causing it to move into the vicinity of the field’s densest region. 

The force tends to align the material specimen such that the magnetic path’s resistance as it passes through the material will be as low as possible.”

Characteristics of Synchronous Reluctance motors

  • To cover the motor’s inherent losses when there is no load, it pulls a very modest current from the mains. 
  • The torque angle rises along with the increase in load torque, and the motor uses more mains current as a result. No further increase in the load is allowed once the input current reaches its maximum (at a torque angle close to 90 degrees). The motor loses synchronism and stops if it is loaded further.
  • A synchronous motor’s speed is unaffected by the load.
  • Synchronous motors do not automatically start themselves. For commencement, certain auxiliary means must be offered.
  • If the load on the shaft is raised while the motor is running past the limit that it can support, the motor will stall.
  • A synchronous motor can be engineered to work with both a lagging and a leading power factor.

Advantages of Synchronous Reluctance Motors

The benefits and drawbacks of synchronous reluctance motors are as follows due to their robust nature.

  • The machine can produce steady speed in any situation thanks to its magnetic locking principle. By synchronizing torque, any change in loads, such as underload or overloads, will be overcome. In every way, the speed will be maintained.
  • It does not require any starting mechanism, unlike synchronous motors, which do and are not self-starting, because of the reluctance principle.
  • The machine is more durable because it self-starts.
  • It requires less maintenance because the construction is less intricate.
  • In contrast to switching reluctance motors, there are no ripple torques.
  • Controlling the power factor is one of the main benefits of using synchronous motors. Induction motors and other lagging power factor loads can be operated in parallel with an over-excited synchronous motor, which has a leading power factor, to increase the system power factor.
  • Wider air gaps can be used to build synchronous motors than induction motors, which increases their mechanical stability.
  • Electromagnetic power in synchronous motors varies linearly with voltage.
  • When compared to induction motors, synchronous motors typically operate at better efficiency (more than 90%), particularly in low-speed and unity power factor applications.
  • For the purposes of excitation, it does not require a d.c. supply. As a result, it requires less upkeep and is less difficult. For the best quality Synchronous Reluctance motors which will not require Continuous maintenance, contact Epoch Automation Pvt Ltd.

Disadvantages of Synchronous Reluctance motors

  • Dc excitation for synchronous motors is necessary and must come from outside sources.
  • Synchronous Reluctance motors require some kind of arrangement for their beginning and synchronizing because they are essentially not self-starting motors.
  • Synchronous Reluctance motors are unable to start while under load. It has no starting torque.
  • These motors are prone to hunting.
  • When a synchronous Reluctance motor is loaded above its capacity, the synchronism between the revolving magnetic fields of the rotor and stator is lost, and the motor shuts off.
  • These motors cannot be used for variable speed applications because the only way to change the speed is to change the frequency of the incoming supply (Variable Frequency Drives). Collector rings and brushes are also needed, which increases maintenance.
  • Applications requiring frequent starting or large beginning torques cannot benefit from synchronous motors.
  • In general, the price per kW output is higher than that of induction motors.
  • Synchronous Reluctance motors cannot start themselves.
  • DC excitation at the rotor is necessary for synchronous motors.
  • Synchronous Reluctance motors are more difficult to build than induction motors.
  • Induction motors are less expensive than synchronous motors.
  • The motor’s major drawback is that no speed control is feasible because of its constant speed application, due to the speed’s inflexibility.
  • The device is also referred to as a doubly excited machine since it requires magnetic fields in both the rotor and the stator. One stimulation is required for the stator, and the other is required for the rotor.
  • In comparison to a DC motor, copper losses are higher due to the three-phase windings.

Epoch Automation is the leading producer of Synchronous Motors and submersible pumps of the highest caliber. Our Synchronous motors and submersible pumps are extremely durable and don’t need frequent maintenance or repairs because they are created using cutting-edge technology. 

All of our items have extended warranties so you won’t have to buy new ones as frequently. Our motors and pumps can all be used in high-rise buildings and the best for that use is our latest product First time in IndiaAn inverted submersible pump.

Try Epoch Automation’s products if you want to receive a return on your investment for your pumps and motors because we have pumps and motors for practically every need, including residential, industrial, agricultural, etc. Get more details about our premium pumps and motors by getting in touch with us at or Whatsapp “Hi” at 7863076092.

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