Three Phase Rare Earth Permanent Magnet Synchronous Motor For Centrifugal Pump

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.
 
 
Permanent magnet AC (PMAC) motors have a wide range of applications including:
 

Working Principle

The permanent magnet synchronous motor working principle is similar to the synchronous motor. It depends on the rotating magnetic field that generates electromotive force at synchronous speed. When the stator winding is energized by giving the 3-phase supply, a rotating magnetic field is created in between the air gaps.
 
This produces the torque when the rotor field poles hold the rotating magnetic field at synchronous speed and the rotor rotates continuously. As these motors are not self-starting motors, it is necessary to provide a variable frequency power supply.
 

Permanent Magnet Motor Centrifugal Pump:

1. High efficiency and energy saving: Adopts IE5 ultra-high energy efficiency permanent magnet variable frequency motor, and permanent magnets are used to provide excitation without excitation current and excitation loss, which provides the efficiency and power density of the motor. Compared with conventional asynchronous motors, the energy-saving rate is as high as 30% or more;

2. Superior performance: The permanent magnet motor adopts permanent magnet rotor rare earth magnetic steel, the entire 304 stainless steel shaft, high speed, stable and accurate synchronous speed, and better performance than conventional asynchronous speed;

3. Easy installation: Small and exquisite, 1/3 smaller than the conventional water pump, easy to install and save space;

4. Safe and reliable: It adopts a permanent magnet dedicated frequency conversion control system, multiple protections, and supports interconnection. Compared with conventional water pumps, it is safer and more intelligent, and permanent magnet motors never burn out.

Structure of the IPM (interior permanent magnet) motor

A conventional SPM (surface permanent magnet) motor has a structure in which a permanent magnet is attached to the rotor surface. It only uses magnetic torque from a magnet. On the other hand, the IPM motor uses reluctance through magnetic resistance in addition to magnetic torque by embedding a permanent magnet in the rotor itself.

SPM vs IPM Motor Rotor Structure

IPM (Interior Permanent Magnet) Motor Features

High torque and high efficiency
High torque and high output are achieved by using reluctance torque in addition to magnetic torque.

Energy-saving operation
It consumes up to 30% less power compared to conventional SPM motors.

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

Safety
Since the permanent magnet is embedded, mechanical safety is improved as, unlike in an SPM, the magnet will not detach due to centrifugal force.

Vector Control Features

While a conventional system (120-degree conduction system) has the current impressed in the motor as a square wave, a vector control impresses voltage which turns into a sine wave towards the rotor's position (angle of the magnet), so it becomes possible to control the motor current.

Working of Permanent Magnet Synchronous Motor:
The working of the permanent magnet synchronous motor is very simple, fast, and effective when compared to conventional motors. The working of PMSM depends on the rotating magnetic field of the stator and the constant magnetic field of the rotor. The permanent magnets are used as the rotor to create constant magnetic flux and operate and lock at synchronous speed. These types of motors are similar to brushless DC motors.
 
The phasor groups are formed by joining the windings of the stator with one another. These phasor groups are joined together to form different connections like a star, Delta, and double and single phases. To reduce harmonic voltages, the windings should be wound shortly with each other.
 
When the 3-phase AC supply is given to the stator, it creates a rotating magnetic field and the constant magnetic field is induced due to the permanent magnet of the rotor. This rotor operates in synchronism with the synchronous speed. The whole working of the PMSM depends on the air gap between the stator and rotor with no load.
 
If the air gap is large, then the windage losses of the motor will be reduced. The field poles created by the permanent magnet are salient. The permanent magnet synchronous motors are not self-starting motors. So, it is necessary to control the variable frequency of the stator electronically.
 

Advantages:

The advantages of permanent magnet synchronous motor include,

Provides higher efficiency at high speeds

Available in small sizes in different packages

Maintenance and installation are very easier than with an induction motor

Capable of maintaining full torque at low speeds

High efficiency and reliability

Gives smooth torque and dynamic performance

Disadvantages:

The disadvantages of permanent magnet synchronous motors are:

These types of motors are very expensive when compared to induction motors

Somehow difficult to start up because they are not self-starting motors.

What factors need to be considered when choosing a permanent magnet motor?

① Consider Your Application Requirements

The first step in choosing a neodymium magnet motor is to consider your application requirements. What power output do you need? What speed and torque requirements does your application have? Answering these questions will help you narrow down your options and choose a motor that will work for your specific application.

② Cost

Of course, the cost is always a factor when making any purchase—and that includes choosing a motor. Permanent magnet motors can range in price from a few hundred dollars to several thousand. Make sure to compare prices from different suppliers before making your decision. But also keep in mind that sometimes, you get what you pay for. So don't choose the cheapest option without doing your research first.

③ Size/Weight

The size and weight of the motor will be determined by your power requirements and the application in which it will be used. If space is at a premium, then you'll need to factor that into your decision-making process.

④ Maintenance

Neodymium magnet motors are generally very low maintenance, but it's still important to consider how easy or difficult it will be to perform routine maintenance tasks like oil changes and brake repairs.

⑤ Efficiency Requirements

Efficiency is another important consideration when choosing a PM motor. Motors with higher efficiency ratings will use less energy, which can save you money in the long run. When comparing efficiency ratings, be sure to compare apples to apples by looking at motors that are the same size and have similar power outputs.

⑥ Durability

Permanent magnet motors are designed for long-term use, but some models are more durable than others. If your application is particularly demanding, then you'll need to make sure that you choose a motor that can stand up to the rigors of your specific application.

⑦ Mounting Options

How will the motor be mounted? Some motors come with multiple mounting options while others are limited to just one or two possibilities. You'll need to make sure that the motor you choose can be mounted in the way that's required for your application

⑧ Pick the Right Supplier

Finally, make sure you pick the right supplier. Working with a reputable supplier who has experience in designing and manufacturing PM motors will help ensure that you get a quality product that meets your specific needs.