Views: 203 Author: James Publish Time: 2026-06-25 Origin: Site
Schematic diagram of SynRM motor structure
A synchronous reluctance motor (SynRM) is a high-efficiency AC motor that produces torque through magnetic reluctance differences in the rotor structure, rather than rotor current or permanent magnets.
Unlike traditional induction motors or permanent magnet motors, SynRM eliminates:
Rotor copper losses
Rare-earth magnet dependency
Slip-based torque production
This makes SynRM a key technology in modern energy-efficient industrial drive systems.
SynRM motors are widely used in modern industrial energy-saving motor systems such as pumps and HVAC systems.
Learn more about our SynRM Motor Solutions.
Table of Contents
Reluctance principle (d-q axis)
A SynRM motor works based on the principle of magnetic reluctance minimization.
Stator generates rotating magnetic field
Rotor follows synchronous speed
No slip occurs
T ∝ (Ld − Lq) × Id × Iq
Ld = direct-axis inductance
Lq = quadrature-axis inductance
Torque depends on rotor anisotropy
This control strategy is optimized through advanced drive systems such as FOC vector control and VFD systems.
See also Industrial Motor Control Systems
Rotor structure
Flux barriers
Magnetic saliency paths
Optimized Ld/Lq ratio
No copper bars
No rotor windings
No electrical rotor losses
Result: significantly higher efficiency.
Comparison Chart of IE Efficiency Classes
Very high partial-load efficiency
Lower total energy consumption
Improved lifecycle cost
No rotor I²R loss
No magnet eddy current loss
Reduced thermal stress
SynRM is commonly used in industrial pump and fan systems requiring high efficiency operation.
Explore Industrial Pump Motor Systems.
Feature | SynRM | Induction Motor |
|---|---|---|
Rotor Loss | Very low | High |
Efficiency | IE4–IE5 | IE2–IE3 |
Slip | None | Required |
Maintenance | Low | Medium |
SynRM is a direct upgrade for energy efficiency projects.
Structural Comparison: SynRM vs. PMSM
Feature | SynRM | PMSM |
|---|---|---|
Torque Source | Reluctance | Permanent magnet |
Rare Earth | No | Yes |
Torque Density | Medium | High |
Cost Stability | High | Medium |
For high torque density applications, PMSM technology is often preferred.
Learn more PMSM Motor Technology
Industrial application scenarios (pumps/fans/HVAC)
Variable flow operation
High energy savings potential
Long operating hours
Continuous operation efficiency
Partial load optimization
Stable torque demand
High reliability operation
Schematic diagram of the VFD system
IE5 efficiency regulations
Rising energy costs
ESG sustainability requirements
Rare-earth supply chain risks
High efficiency
No rare-earth materials
Low rotor losses
High reliability
Lower torque density than PMSM
Requires VFD control system
Needs optimized design
SynRM motors represent a major step forward in industrial motor technology, offering:
High efficiency
Low lifecycle cost
Sustainable material usage
They are ideal for pumps, fans, compressors, and industrial energy-saving retrofit projects.
SynRM motors are widely used in pumps, fans, compressors, and HVAC systems where energy efficiency is critical.
Yes. SynRM motors are significantly more efficient, especially under variable load conditions, due to the absence of rotor losses.
No. SynRM motors are completely magnet-free and do not require rare-earth materials.
The main advantage is high energy efficiency with low operating cost in long-term industrial applications.
Yes. SynRM motors require variable frequency drives for optimal performance and control.
SynRM is better for cost-sensitive energy-saving systems, while PMSM is better for high torque density and precision applications.
