PSM motors Used in Forklifts: Construction, Working, and Features
Reading time: 5 min 11 sec.
InMotion brings significant expertise in the design and manufacturing of a range of motors to today's electric car industry. InMotion initially focused on low-voltage motors. These motors could withstand the severe environmental conditions encountered by forklifts.
Over the years, the company has gained significant experience in motors and generators. They provide for both high-voltage and low-voltage vehicle application motors. InMotion can help you with different products, whether you need a lower-cost induction motor or an efficient high-power generator.
InMotion PSM Motors is the most efficient, provides a high level of performance, is very slender, and is good in usage.
In this article, you will learn the concept of PSM Motors for Forklifts, construction of PSM Motor, working of the synchronous motor, and features of InMotion PSM Motor.
Today, more companies are using electric forklifts to replace manual forklift systems. The electric forklift power system uses drive engines, and electric forklifts drive motors. They are usually DC or AC.
An electric forklift's DC motor introduces current into the rotor armature via brushes and commutators. It causes the rotor to rotate in the magnetic field produced by the stator.
An electric forklift's AC motor circulates alternating current through the stator windings. It creates a rotating magnetic field in the air gaps between the stator and rotor. The current generated by the rotating magnetic field induces a current in the rotor windings. It causes the rotor to rotate in the magnetic field generated by the stator.
Forklift PSM motor is a permanent-magnet synchronous motor. These magnets produce an electromagnetic field in all directions. The stator has windings linked to an alternating current source to generate a rotating magnetic field as an asynchronous motor. When the rotor rotates at synchronous speed, the rotor poles lock onto the spinning magnetic field. These forklift motors are comparable to brushless DC motors in their operation.
It provides more power density than an induction motor. It is a cross between an induction motor and a brushless DC motor. These motors are more used in electrical drives due to their many benefits: discrete design alternatives and integrated motor controller circuits (ICs).
Construction of PSM Motor
A PSM Motor of a forklift is composed of two parts:
The rotor is the component that rotates, and the stator remains fixed.
Although the rotor of an electric motor is often placed within the motor’s stator, some constructions have an external rotor. Inside-out electric motors are also available.
Permanent magnets are used to construct the rotor. The use of materials with a high coercive force makes it possible to use permanent magnets.
Synchronous motors are classified into two types based on the rotor design:
Electric motors with salient pole rotors
Electric motors with non-salient pole rotors
An electric motor with a salient pole rotor does not have equal direct and quadrature inductances Lq ≠ Ld. While an electric motor with a non-salient pole rotor has equal direct and quadrature inductances Ld = Lq,
In addition, permanent magnet synchronous motors are classified into two types based on the architecture of the rotor:
Surface permanent magnet synchronous motors
Internal permanent magnet synchronous motors
The stator comprises two parts:
An outer frame
A core filled with windings
Two- and three-phase windings are used in the most typical configuration of this design.
Depending on the stator design, a permanent magnet synchronous motor may be classified as distributed and concentrated winding.
Such a winding is called a distributed winding where the number of slots per pole and phase, Q = 2, 3,..., k.
This kind of winding is concentrated. It has several slots per pole and phase Q = 1. In this instance, the spaces are equally placed around the circle of the stator, as seen in the figure. The two coils that make up the winding may be linked in both series and parallel configurations. In this case, the major disadvantage is the impossibility of influencing the form of the EMF curve.
The back Electromotive Force (EMF) of an electric motor may take on the form of a trapezoidal or a sinusoidal wave. The distribution curve of magnetic induction in the gap determined the form of the EMF curve in the conductor around the perimeter of the stator.
The magnetic induction in the gap under the salient pole of the rotor has a trapezoidal form. The EMF induced in the conductor has the same trapezoidal form. The pole tips are given a form so that the induction distribution curve is as close to the sinusoidal as possible if it is required to generate a sinusoidal EMF.
Working of the synchronous motor
The working of the synchronous motor is based on the interaction between the rotating magnetic field produced by the stator and a constant magnetic field produced by the rotor. It is the same concept as the rotating magnetic field generated by the stator of a three-phase induction motor when considering synchronous motors.
According to Ampere's Law, the rotor’s magnetic field interacts with the synchronous alternating current of the stator windings to produce torque. It causes the rotor to spin.
Permanent magnets mounted on the rotor of the PSM provide a magnetic field. This field is constantly changing. Rotor poles interlock with the stator’s rotating magnetic field at a rotational speed equal to or faster than the stator field rotational speed. When the PSM motor is connected directly to the three-phase current network, it will not start by itself. The current frequency in the power grid is 50Hz.
Features of InMotion PSM Motor
High level of efficiency and performance
InMotion PSM Motors have high performance and efficiency levels, particularly in the partial-load region. It is because of the employment of high-quality permanently magnetic materials.
Good in usage
The usage of these motors is recommended in situations where severe requirements are put on utilization. In terms of available space, dynamic capabilities (overload), speed control range, and motor efficiency. These motors are also cost-effective in situations where space constraints are not a problem.
Extremely Slender Motors
The high-performance characteristics of these motors allow for a considerable reduction in power needs and a reduction in the overall size of the inverter. Permanent magnets allow the extremely slender construction of motors.
The key takeaways include:
Forklift PSM motors are permanent-magnet synchronous motors that utilize permanent magnets. These magnets are implanted in a steel rotor to produce an electromagnetic field.
A Forklift PSM motor is composed of two parts: the stator and the rotor. The rotor is the component that rotates, and the stator remains fixed.
The working of the synchronous motor is based on the interaction between the stator and rotor.