A CT450132 permanent magnetic coupler installed on a 132kW/1480rpm belt conveyor of the coal handling system for the 2×1,000,000 kW generating units in the Phase III Project of Huainan Pingwei Power Plant has successfully passed the 168-hour trial operation. The relevant experience is summarized as follows.

II. Equipment Description of Permanent Magnetic Coupler

1. Equipment Model: CT450132;

2. Installation Type: Horizontal Installation;

3. Functional Feature: Torque Limiting Type;

4. Application Location: Coal Handling System;

5. Motor Parameters: 132kW/1480rpm

III. Installation Description

1. Reserve a spacing of 200mm between the shaft ends of the motor and reducer during design;

2. The installation is similar to that of a coupling;

3. Check the gaps on both sides, which shall be uniform and each 3.172mm with a tolerance not exceeding 1mm.

4. Install Legend

IV. Commissioning Status

1. After startup, the motor and the connected conductor disc quickly reach the rated speed of the motor. The permanent magnet connected to the load accelerates gradually and finally maintains a constant speed, completing the starting process;

2. It operates smoothly with extremely low vibration;

3. The speed of the load is slightly 2% lower than that of the motor.

V. Usage and Maintenance

1. Adaptable to various harsh environments, unaffected by dust, temperature, muddy water and sludge;

2. Free of bearings and other vulnerable parts, it can be maintained in the same manner as coupling products with no regular maintenance required.

VI. Overload Protection

1. The torque-limiting permanent magnet coupling can realize the overload protection function during operation. When the load is suddenly overloaded or locked, it can quickly widen the gap between the magnetic disk and the conductor disk, cutting off torque transmission between the motor and the load. This makes the motor run under no load and protects the motor;

2. The above situation has not occurred so far;

3. Relevant tests will be conducted later to verify its performance.

VII. Safety and Stability

1. The buffered soft start reduces impact on the power grid and equipment, and lowers tension fluctuation of the belt conveyor during startup;

2. It lessens the impact on mechanical equipment, belts and joints;

3. The starting current is low, which is beneficial to the motor;

4. The torque-limiting overload protection function can effectively protect rotating components such as motors, loads, shafts and bearings;

5. After the motor stops, the permanent magnet coupling can reset automatically and be restarted immediately without time delay, featuring higher reliability than fluid couplings.

VIII. Advantages of Torque-Limiting Permanent Magnet Coupling

1. Buffered Soft Start: Reduces the inrush current of the motor and extends the service life of equipment.

2. Torque Limitation and Automatic Stall Protection: When the load is overloaded, the air gap between the conductor disc and the permanent magnet disc automatically widens, enabling the motor to run under light load or no load without jamming, thus protecting the motor.

3. Tolerance for Large Installation Misalignment Errors: Greatly simplifies the installation and commissioning process.

4. Overload Protection Function: Improves the reliability of the entire motor drive system.

5. Low Maintenance: Simple structure with minimal maintenance requirements.

6. Long Service Life: A service life of 30 years.

7. Excellent Vibration Damping Effect: Torque transmission without mechanical connection.

8. Simple Structure: Adaptable to various harsh environments, produces no pollutants and complies with green product standards.

9. Energy-saving Effect: Reduces starting inrush current with an energy-saving rate of 5%-20%.

10. No Harmonic Generation.