Direct Drive Neodymium Magnet Motor IP54 90kw Variable Speed AC Motor

In the general industrial sector, the replacement of low-voltage(380/660/1140V) high-efficiency asynchronous motors, the system saves 5% to 30% energy, and the high-voltage(6kV/10kV) high-efficiency asynchronous motors, the system saves 2% to10%.

Why choose permanent magnet ac motors?

Permanent magnet AC (PMAC) motors offer several advantages over other types of motors, including:

High Efficiency: PMAC motors are highly efficient due to the absence of rotor copper losses and reduced winding losses. They can achieve efficiencies of up to 97%, resulting in significant energy savings.

High Power Density: PMAC motors have a higher power density compared to other motor types, which means they can produce more power per unit of size and weight. This makes them ideal for applications where space is limited.

High Torque Density: PMAC motors have a high torque density, which means they can produce more torque per unit of size and weight. This makes them ideal for applications where high torque is required.

Reduced Maintenance: Since PMAC motors have no brushes, they require less maintenance and have a longer lifespan than other motor types.

Improved Control: PMAC motors have better speed and torque control compared to other motor types, making them ideal for applications where precise control is required.

Environmentally Friendly: PMAC motors are more environmentally friendly than other motor types since they use rare earth metals, which are easier to recycle and produce less waste compared to other motor types.

Overall, the advantages of PMAC motors make them an excellent choice for a wide range of applications, including electric vehicles, industrial machinery, and renewable energy systems.

Application:

Permanent magnet synchronous motors can be combined with frequency converters to form the best open-loop step-less speed control system, which has been widely used for speed control transmission equipment in petrochemical, chemical fiber, textile, machinery, electronics, glass, rubber, packaging, printing, paper making, printing and dyeing, metallurgy and other industries.

A permanent magnet motor (also called PM) can be separated into two main categories: Interior Permanent Magnet (IPM) and Surface Permanent Magnet (SPM). Both types generate magnetic flux by the permanent magnets affixed to or inside of the rotor.

SPM

SURFACE PERMANENT MAGNET

A type of motor in which permanent magnets are attached to the rotor circumference.

SPM motors have magnets affixed to the exterior of the rotor surface, their mechanical strength is so weaker than the IPM one. The weakened mechanical strength limits the motor’s maximum safe mechanical speed. In addition, these motors exhibit very limited magnetic saliency (Ld ≈ Lq). Inductance values measured at the rotor terminals are consistent regardless of the rotor position. Because of the near unity saliency ratio, SPM motor designs rely significantly, if not completely, on the magnetic torque component to produce torque.

IPM

INTERIOR PERMANENT MAGNET

A type of motor that has a rotor embedded with permanent magnets is called IPM.

IPM motors have a permanent magnet embedded into the rotor itself. Unlike their SPM counterparts, the location of the permanent magnets makes IPM motors very mechanically sound, and suitable for operating at very high speeds. These motors also are defined by their relatively high magnetic saliency ratio (Lq > Ld). Due to their magnetic saliency, an IPM motor has the ability to generate torque by taking advantage of both the magnetic and reluctance torque components of the motor.

Why you should choose an IPM motor instead of an SPM?

1. High torque is achieved by using reluctance torque in addition to magnetic torque.

2. IPM motors consume up to 30% less power compared to conventional electric motors.

3. Mechanical safety is improved as, unlike in an SPM, the magnet will not detach due to centrifugal force.

4. It can respond to high-speed motor rotation by controlling the two types of torque using vector control.

Brushless permanent magnet (PM) motors operate with an AC power supply so are often referred to as PMAC motors. The use of permanent magnets eliminates the need for conductors (rotor bars) so rotor losses are eliminated. This design makes it possible to combine high efficiency, low speed, and high torque in a single package. For small motor sizes, the efficiency of the PM motor maybe 10% to 15% greater than older, standard-efficiency motors at the same load point. These efficiency gains hold over the entire range of typical motor loads.

How to improve the efficiency of the motor?

To improve the efficiency of the motor, the essence is to reduce the loss of the motor. The loss of the motor is divided into mechanical loss and electromagnetic loss. For example, for an AC asynchronous motor, the current passes through the stator and rotor windings, which will produce copper loss and conductor loss, while the magnetic field is in the iron. It will cause eddy currents to bring about hysteresis loss, high harmonics of the air magnetic field will generate stray losses on the load, and there will be wear losses during the rotation of bearings and fans.

To reduce the loss of the rotor, you can reduce the resistance of the rotor winding, use a relatively thick wire with low resistivity, or increase the cross-sectional area of the rotor slot. Of course, the material is very important. Conditional production of copper rotors will reduce losses by about 15%. The current asynchronous motors are basically aluminum rotors, so the efficiency is not so high.

Similarly, there is copper loss on the stator, which can increase the slot face of the stator, increase the full slot ratio of the stator slot, and shorten the end length of the stator winding. If a permanent magnet is used to replace the stator winding, there is no need to pass the current. Of course, the efficiency can be obviously improved, which is the fundamental reason why the synchronous motor is more efficient than the asynchronous motor.

For the iron loss of the motor, high-quality silicon steel sheets can be used to reduce the loss of the hysteresis or the length of the iron core can be lengthened, which can reduce the magnetic flux density, and can also increase the insulating coating. In addition, the heat treatment process is also critical.

The ventilation performance of the motor is more important. When the temperature is high, the loss will of course be large. The corresponding cooling structure or additional cooling method can be used to reduce friction loss.

High-order harmonics will produce stray losses in the winding and iron core, which can improve the stator winding and reduce the generation of high-order harmonics. Insulation treatment can also be performed on the surface of the rotor slot, and magnetic slot mud can be used to reduce the magnetic slot effect.

Due to the need for a drive or controller, variable-speed PMAC motors cost much more than constant-speed Premium Efficiency induction motors. PM motors have variable-speed capability, however, so are equivalent replacements for an electronic pulse-width modulated variable frequency drive (VFD) controlling a new Premium Efficiency inverter-duty motor. When replacing constant-speed motors in variable flow applications, energy savings due to the variable-speed capability of the PMAC motor will greatly exceed the savings due to the increased efficiency of the motor itself. Permanent magnet motors provide improved efficiency over their entire operating range and meet or exceed the International Electrotechnical Commission (IEC) IE4 efficiency standards.