What Is a Reluctance Motor?

A reluctance motor is a continuous-running electrical transmission device. Its structure and working principle are very different from traditional AC and DC motors. It does not rely on the interaction of the magnetic field generated by the stator and rotor winding currents to generate torque, but instead relies on the "minimal resistance principle" to generate torque.

The main reason is that the horizontal and vertical axis magnetic fluxes are different. Depending on the change of this magnetic flux, a synchronous torque (also known as reluctance torque) is generated to maintain the motor running at a specific synchronous speed. The generation of reluctance torque can be described by the image of magnetic field lines being skewed in FIG. 1.

As the rotor rotates, the reluctance of the magnetic circuit must change as much as possible. Therefore, the stator and rotor of the electric motor both adopt a double salient pole structure and are stacked with silicon steel sheets. A simple concentrated winding is installed on each stator magnetic pole, and the windings on the two radially opposite stator magnetic poles form a phase in a series or parallel manner. There are no windings or permanent magnets on the rotor. According to the phase number of the motor, it can be divided into odd phase and even phase. According to the magnetic circuit structure of the motor, it can be divided into two-pole long magnetic circuit structure and four-pole short magnetic circuit structure. According to the energizing excitation mode of the motor, there are single-phase excitation and multi-phase excitation.

Magnetoresistive effect is a phenomenon in which resistance increases in a magnetic field. The magnetoresistive effect is particularly significant in semiconductors. The magnitude of the effect is usually measured by the ratio of the change in resistance to the resistance itself:

₀ and _B are the resistances when there is no magnetic field and when there is a magnetic field, respectively. In general, the magnitude of the magnetic resistance is related to the crystal orientation along which the current flows and the relative orientation of the current and the magnetic field. The reluctance when the current and the magnetic field are perpendicular to each other is called transverse reluctance; when the current is parallel to the magnetic field, it is called longitudinal reluctance.

In the magnetic field, due to the Lorentz force, the movement of carriers will generally be deflected, which is the reason for the magnetoresistive effect. However, in the case of a simple energy band with a spherical isoenergetic surface, the longitudinal magnetic resistance is zero. Because in this case, the drift velocity is parallel to the magnetic field. The existence of the magnetic field does not change the carrier's drift motion, but the transverse magnetic resistance is generally not zero. In the transverse magnetic field, the carriers that move in drift are simultaneously affected by the Lorentz force and the electrostatic force generated by the Hall electric field. The effects of these two forces cancel each other out on the whole, making the transverse current zero. However, in the case where the momentum relaxation time is dependent on energy, carriers with different energies have different average (drift) velocities, and the magnitudes of the Lorentz forces are different. It is just the Lorentz force on the carrier of a certain energy (average velocity) and

Is magnetic resistance

Direct current machine (direct current machine) refers to a rotating electrical machine that can convert DC energy into mechanical energy (DC motor) or mechanical energy into DC energy (DC generator). It is a motor that can convert DC electrical energy and mechanical energy to each other. When it is used as a motor, it is a DC motor, which converts electrical energy into mechanical energy; when it is used as a generator, it is a DC generator, which converts mechanical energy into electrical energy.

The structure of a DC motor should be determined by

"AC motor" is a machine used to achieve the mutual conversion of mechanical energy and AC energy. Due to the tremendous development of AC power systems, AC motors have become the most commonly used motors. Compared with DC motors, AC motors do not have a commutator (see DC motor commutation), so they have a simple structure, are easy to manufacture, and are relatively solid. The coverage of AC motor power is very large, from several watts to hundreds of thousands of kilowatts, and even millions of kilowatts. In the early 1980s, the largest turbo-generators reached 1.5 million kilowatts. The AC motor was invented by American Serbian scientist Nikola Tesla.

Description with single-phase capacitor motor: single-phase motor has two windings, namely the starting winding and the running winding. The two windings are spaced 90 degrees apart. A large-capacity capacitor is connected in series with the starting winding. When the running winding and the starting winding pass a single-phase AC current, the current in the starting winding is advanced by 90 degrees in time from the current of the running winding due to the capacitor, and reaches the maximum value first. value. Two identical pulsed magnetic fields are formed in time and space, so that a rotating magnetic field is generated in the air gap between the stator and the rotor. Under the effect of the rotating magnetic field, an induced current is generated in the motor rotor, and the current and the rotating magnetic field interact to produce Electromagnetic field torque makes the motor rotate. ^[4]