Replacement Strategy: Directly swap asynchronous motors with PMSM of equivalent power.
• Result: 3–10% energy savings, higher power factor (near 1.0).
System Overhaul: Replace "asynchronous motor + gearbox + coupling" with low-speed PMSM direct drive.
• Result: 10–25% energy savings, reduced maintenance (no gear oil leaks, bearing wear).
Case: Baotou Steel’s ore conveyor retrofit saved 10% electricity with PMSM direct drive.
High-Pressure Blowers (e.g., blast furnace air supply):
• PMSM + VFD enables soft starts (reducing mechanical stress) and precise airflow control.
• Energy Saving: 20–30% via load-proportional speed regulation.
Exhaust Fans (e.g., sintering plant dust removal):
• Case: HBIS Group’s 400kW fan retrofit cut current draw from 29A → 21A (28% reduction).
Variable Flow Control: PMSM + VFD replaces throttle valves, eliminating hydraulic losses.
Energy Impact:
• Motor-only replacement: 3–5% savings.
• Full system upgrade: >20% savings.
Case: One Vietnam Steel’s central cooling pumps reduced annual costs by ¥1M+.
Ball/Rod Mills: High-torque PMSMs enable direct drive, removing gearboxes.
• Outcome: 25% lower power use (e.g., Meishan Mining), reduced vibration/noise.
|
Feature |
Benefit in Steel Plants |
|
High Efficiency |
95–97% efficiency vs. 90–93% for induction motors; maintains >90% efficiency at 20–125% load. |
|
Power Factor ~1.0 |
Reduces reactive power compensation needs; cuts grid losses. |
|
Compact Size |
20–30% smaller frame vs. induction motors; ideal for retrofits. |
|
Low Maintenance |
No brushes/rotor windings; sealed units resist dust/humidity. |
|
Precision Control |
Near-zero speed ripple with servo drives; critical for tension control in rolling mills. |
Retrofit:
Quick wins by replacing existing motors (e.g., pumps/fans). ROI: <2 years.
Integrated Direct Drive:
New installations (e.g., conveyors, mills) eliminate reducers/couplers. ROI: 3–5 years.
Smart Motor Systems:
Embed IoT sensors for predictive maintenance (e.g., vibration/temp monitoring).
|
Equipment |
Power Rating |
Energy Saved |
Payback Period |
|
Ore Conveyor |
250 kW |
10–15% |
1.8 years |
|
Sinter Plant Fan |
400 kW |
22% |
2.1 years |
|
Cooling Water Pump |
180 kW |
28% |
1.5 years |
High Capital Cost:
PMSM costs 1.3–1.8× induction motors → offset by energy savings in <3 years.
Rare-Earth Dependency:
NdFeB magnets vulnerable to price volatility → use ferrite magnets for <100kW applications.
Heat Management:
High ambient temps in steel mills → adopt forced-air cooling or liquid-cooled housings.
PMSMs are transforming steel manufacturing by:
✔️ Cutting energy use by 15–30% in key processes (fans/pumps/conveyors).
✔️ Enabling direct-drive solutions to boost reliability.
✔️ Slashing CO₂ emissions (e.g., 500 tons/year reduction per 1MW motor).
