What is the difference between a normal motor and a permanent magnet motor?

These are two different classifications and cannot be compared.

Motors made of permanent magnets are called permanent magnet motors, and non-permanent magnet motors that do not use permanent magnets (electromagnets) are called non-permanent magnet motors; Those that use direct current are called DC motors, and those that do not use direct current (use alternating current) are AC motors.

Permanent magnet motors can be either DC motors or AC motors (e.g., household breeze ceiling fans); Similarly, the use of permanent magnets can be DC motors, AC motors, or even AC and DC dual-purpose.

Compared with general motors, permanent magnet motors have high power density, which mainly refers to the small size of permanent magnet motors and large power generation or output power. Compared with the general motor energy saving of 20%-40%. The rotor structure of the permanent magnet motor is different from that of the general motor, and the rotor of the permanent magnet motor is equipped with a permanent magnet pole; Generally, an excitation coil is installed on the rotor of the motor, and the magnetic field is only when the demand current is transferred.

Compared with traditional motors, any speed point can save electricity, especially when the speed is low. Most modern submarines use large-diameter, low-speed, 7-blade large-side-inclined propellers or pump-jet thrusters, which have low speed and high propulsion efficiency. Moreover, submarines mostly maneuver at low-noise speed underwater, which makes this advantage of permanent magnet motor better reflected and exerted.

First, small size, light weight.

The structure of the permanent magnet motor is simple, due to the use of high-performance permanent magnet data to provide the magnetic field, the air gap magnetic field of the permanent magnet motor is greatly enhanced compared with the general motor, and the volume of the permanent magnet motor is greatly reduced compared with the general motor, and the size and shape of the motor are also flexible and diverse.

Second, the failure rate is lower and widely used.

Due to the use of high-performance rare earth permanent magnet materials to provide magnetic fields, the failure rate is lower, and the use is becoming more and more widespread.

3. Large starting torque.

Since the rotor windings do not work during normal operation of permanent magnet motors, the rotor windings can be designed to meet the requirements of high starting torque, such as from multiple to multiple, or even larger.

The difference between permanent magnet motor and ordinary motor is: 1. Magnetic field properties. After the permanent magnet motor is made, it does not need external energy to maintain its magnetic field; Ordinary motors require current to be fed in order to have a magnetic field.

2. Rotor structure. The rotor of the permanent magnet motor is provided with a permanent magnet pole; An excitation coil is installed on the rotor of an ordinary motor. 3. Applicable occasions.

Permanent magnet motors are usually used in low-power applications; Ordinary motors, especially excitation motors, are often used in high-power applications. Features: Permanent magnet motor is a form of rectangular pulse wave, current sine wave current, hybrid permanent magnet motor.

Simple structure, high reliability and high efficiency. Ordinary motors have fast response, large starting torque, and can provide rated torque from zero speed to rated speed. Introduction to Permanent Magnet Motors:

The permanent magnet DC motor is also composed of stator poles, rotors, brushes, shells, etc., and the stator poles are made of permanent magnets (permanent magnets), with ferrite, alnico, neodymium iron boron and other materials. According to its structural form, it can be divided into cylindrical type and tile type. Most of the electricity used in VCRs is cylindrical magnets, while most of the motors used in power tools and automotive appliances use special block magnets.

The rotor is generally made of silicon steel sheets, which has fewer slots than the rotor of electromagnetic DC motors. Most of the low-power motors used in VCRs are 3-slot, and the higher-end ones are 5-slot or 7-slot. The enameled wire is wound between two slots in the rotor core (three slots have three windings), and its joints are welded to the metal sheet of the commutator.

Brushes are conductive parts that connect the power supply to the rotor windings, and have both conductive and wear-resistant properties. The brushes of the permanent magnet motor use single metal sheets or metal graphite brushes, and electroized graphite brushes. The permanent magnet DC motor used in the VCR adopts an electronic speed stabilization circuit or a centrifugal speed stabilization device.

Ordinary motor: motor refers to an electromagnetic device that realizes the conversion or transmission of electrical energy according to the law of electromagnetic induction, and its main role is to use mechanical energy to convert into electrical energy and generate driving torque, as a power source for electrical appliances or various machinery. At present, the most commonly used is to use thermal energy, hydro energy and other power to drive the rotor of the generator to generate electricity, with the maturity of wind power generation technology, wind power has slowly entered our lives.

Working power supply types: can be divided into DC motor and AC motor, DC motor is a motor that relies on DC working voltage to run, widely used in cassette recorders, video recorders, DVD players, electric shavers, hair dryers, electronic watches, toys, etc.

What do permanent magnet motors use to generate power, and why are there no excitation coils? Today I know it.

The permanent magnet external rotor motor is a permanent magnet direct drive drum. The permanent magnet direct-drive drum shaft is fixed, which is equivalent to the stator part of the motor, and the stator core is superimposed and fixed on the shaft by silicon steel sheets, in which the stator winding is embedded, and when the stator winding passes three symmetrical alternating current, a rotating magnetic field can be generated; The simple surface of the drum is equivalent to the rotor part of the motor, and the rotor is superimposed and fixed on the inner surface of the simple by the silicon steel sheet, and the UH grade NdFeB permanent magnet is embedded in it, which will generate a permanent static magnetic field, and when the symmetrical three-phase alternating current is introduced, the motor works, that is, the drum works.

What do permanent magnet motors use to generate power, and why are there no excitation coils? Today I know it.

Permanent magnet motors are AC motors. The permanent magnet acts as the rotor to generate a rotating magnetic field, and the three-phase stator winding reacts through the armature under the action of the rotating magnetic field to induce a three-phase symmetrical current.

At this time, the rotor kinetic energy is converted into electrical energy, and the permanent magnet synchronous motor is used as a generator; In addition, when a three-phase symmetrical current is introduced into the stator side, because the three-phase stator differs by 120 in space, the three-phase stator current generates a rotating magnetic field in space, and the rotor is moved by electromagnetic force in the rotating magnetic field, and the electrical energy is converted into kinetic energy.

In changing the excitation current of the generator, it is generally not directly carried out in its rotor circuit, because the current in the circuit is very large, and it is not convenient to adjust it directly, and the method usually adopted is to change the excitation current of the exciter to achieve the purpose of regulating the rotor current of the generator.

Commonly used methods include changing the resistance of the exciter excitation circuit, changing the additional excitation current of the exciter, and changing the conduction angle of the thyristor.