# Magnetoelectric machine with improved rotation uniformity

FIELD: electricity.

SUBSTANCE: invention is related to the area of electric engineering and namely to electric machines with permanent-magnet excitation, and it may be used in electric machine engineering. At that the invention ensures improved rotation uniformity, enhanced energy indicators, reduction of noise and vibration level for the magnetoelectric machine. In the suggested magnetoelectric machine including armature with winding laid in z slots and non-salient pole rotor with permanent magnets the armature slots are bevelled at the angle α corresponding to an integer number of tooth harmonic periods.

EFFECT: decreasing reactive moment pulsation for the magnetoelectric machine.

The invention relates to the field of electrical engineering, namely to electric machines with excitation from permanent magnets, and can be used in electrical engineering.

It is known that in magnetoelectric machine there is the effect of "sticking" of the rotor, which significantly affects the smooth operation of the actuator at low frequencies of rotation of the rotor, thus reducing the range of the speed control actuator and limiting the scope of its application [1, p.45].

The main reason for the violation smooth movement of the rotor ("sticking" of the rotor) is the reactive torque, which reduces the starting torque magneto-electric machine, causes the stop of the rotor in certain positions and increases the irregularity of rotation of the magneto-electric machines [2, ñ.38].

Under reactive torque magneto-electric machines understand the time, resulting in an electric car due to the timing structure of the anchor, the asymmetry of its magnetic circuit and uneven working gap [2, ñ.38].

The reactive torque, which is one of the components of the ripple torque, not dependent on the shape of the supply current and supply voltage, as maintained in the de-energized state of the electromagnetic machine.

Due to the timing structure of the stator curve reactive moment is different from the sine wave and is otlozhenii it in Fourier series obtained spectrum of harmonics, called subcommi [5, s-457].

The slant grooves is the most effective way of dealing with subcommi harmonics.

Closest to the claimed technical solution is an electric machine with the bevel grooves of the stator on the pole arc, equal to the whole number Zubovich divisions stator [5, s-459]. The disadvantage of this technical solution is the most discrete accept the bevel grooves and, as a consequence, the decrease of the coefficient of skewness and EMF, which leads to a decrease in the energy parameters of the electric machine.

The objective of the invention is to minimize torque reaction, which is the reason for reducing the uniformity of rotation of the rotor of the magneto-electric machine.

The technical result, which directed the proposed solution is to reduce the ripple torque reaction magnetoelectric machine containing the armature winding, arranged in grooves z, and neravnopolochny rotor with permanent magnets, the execution of the bevel grooves anchors on the angle α, corresponding to a whole number of periods of the sockets harmonics.

Theoretical analysis and calculation of the reactive moment is very difficult. In General, the expression for the reactive moment M_{p}magneto-electric machine can be written as follows [2, ñ.38]

where k is a constructive factor;

F is the magnetic flux of the permanent magnet, WB;

λ is the conductivity of the magnetic circuit, GN;

θ is the angle of rotation of the rotor, al. the hail.

The dependence of conductivity λ of the angle of rotation θ is due to the influence of serration anchors and can be written in the form [3, s]

where n is the number of harmonics;

λ_{0}- constant component of the magnetic conductance, GN;

λ_{p}- the variable component of the magnetic conductance, GN;

z - number of teeth.

Then