RU149269U1 - ELECTRIC VEHICLE DRIVE - Google Patents

Abstract

Electric transport drive, including an electric energy source integrated into an electric circuit, a controlled frequency converter-recuperator and an alternating current electric machine made in the form of an asynchronous motor with a short-circuited rotor and stator, in the grooves of which are placed stator winding coils connected to the star-shaped phases -tangle, characterized in that the stator winding is made of six-phase and axially symmetric with the ratio of the number of turns of the triangle and the star equal to each y has an equal number of grooves, coils of different phases are stacked in different grooves so that the resulting magnetic flux vectors of adjacent phases form an electric angle of 27-34 °, the phases are connected to a star and a triangle through one to form leads spaced 27 apart -34 ° and interconnected to form phase connection points.

Description

The utility model relates to the field of mechanical engineering, in particular to electric drives and can be used in the manufacture of vehicles such as electric cars and cars with hybrid engines.

Three-phase asynchronous motors are known in the prior art, in which the higher harmonics are suppressed mainly due to the use of a stator winding made as a composite in two parts — two independent three-phase windings connected, respectively, to a triangle and a star, each of which is connected to supply network, while the beginning of the same phases of both windings are displaced in space relative to each other by 30 electrical degrees and the magnetic induction vector of each phase crosses the axis of the magneto gadfly.

(Патент РФ ИЗ №2046515, Н02К 17/06, 20.10.1995).In particular, a two-pole asynchronous motor is known, the stator winding of which is made in such a way that the shortening of the pitch of both parts of the winding is set in the range from 0.388 to 0.416 with a ratio of the number of turns of a triangle and a star equal to

(RF patent IZ No. 2046515, Н02К 17/06, 10/20/1995).

Compared with the well-known three-phase asynchronous motor, in which the stator winding is made in the form of sections of many turns of an insulated copper wire connected in different groups, which are connected in a star or a triangle, the above analog has several advantages and differs, first of all, by a higher specific power and increased energy characteristics. So, with overload, the analog shaft speed decreases, but the current practically does not increase. The same thing happens with a sudden drop in voltage in the circuit. The engine continues to work economically at lower speeds without overheating. After restoring the supply voltage to the nominal level, the analogue automatically starts and enters the calculated mode of operation. This is an ideal quality during a “difficult start-up” with a long transient time, when it is necessary to “untwist” the load with a moment of resistance significantly, 2-3 times or more, exceeding the rated moment. When underloaded, the power factor of a conventional engine drops sharply, falling into the region of low values. When overloaded, the shaft speed of a conventional motor decreases slightly, and the current rises sharply, the motor overheats. When underloaded, the power factor of the analog decreases smoothly, remaining in the region of high values, due to which such an electric motor works very economically. The efficiency of a conventional engine drops sharply with a decrease in the supply voltage, and the efficiency of the analog decreases smoothly, maintaining high rates even with significant voltage drops (30% or more).

At the same time, the analogue has a number of disadvantages, in particular: increased complexity and material consumption of manufacturing, caused by increased consumption of groove and frontal isolation, low level of safety, caused by increased potential between sections located in the same groove, which in turn entails increased consumption of groove and frontal isolation. In addition, the efficiency is not high enough due to the inability to make a machine with a phase shift of the windings to a fractional number of grooves (for example, the stator has 36 grooves, the winding is 2p = 4, i.e. the stator contains 720 electrical degrees, therefore, 20 electrical degrees, and the shift in the onset of phases should be 1.5 grooves, which is practically impossible in the analogue).

The closest solution in technical essence and the achieved result is an energy-saving drive for electric transport which consists of an electric energy source, a controlled frequency converter-recuperator and an electric alternating current machine in the form of a four-phase squirrel-cage induction motor or in the form of “Russian parametric electric motor Yalovega” (RF Patent PM No. 107648, Н02К 7/00, 03/25/2011).

The advantages of the prototype include an increase in the specific power of the engine, a decrease in the starting current and an increase in the starting torque of the drive.

The disadvantages of the prototype are: a low level of security caused by the increased potential between sections located in the same groove, which in turn entails an increased consumption of groove and frontal isolation, increased complexity and material consumption of manufacturing, caused by increased consumption of groove and frontal isolation. In addition, the efficiency is not high enough, due to the inability to make a machine with a phase shift of the windings by a fractional number of grooves.

The objective of the utility model is to optimize the design of the drive of electric vehicles by increasing the fill factor of the groove with copper by reducing the diameter of the wires of the "star" by ~ 1.7 and the "triangle" by ~ 2.8 times compared to a standard electric motor by reducing the groove insulation, increasing the specific power by increasing the phase shift (cos φ), the possibility of manufacturing a machine with a fractional number of grooves of the phase shift due to the use of the phase shift range from 27 to 34 electrical degrees, as well as increasing the breakdown resistance due to finding in one slot of like phase windings.

The technical result achieved in this case is to increase the safety of the electric vehicle drive while increasing its efficiency.

, на каждую фазу приходится равное число пазов, катушки различных фаз уложены в разные пазы так, что результирующие векторы магнитного потока соседних фаз образуют между собой электрический угол 27-34°, фазы через одну соединены в звезду и треугольник с образованием выводов, отстоящих друг от друга на 27-34° и соединенных между собой с образованием точек подключения фаз.The stated task and the claimed technical result are achieved by the fact that in the electric transport drive, including a source of electric energy integrated in an electric circuit, a controlled frequency converter-recuperator and an electric alternating current machine, made in the form of an induction motor with a short-circuited rotor and stator, in the grooves of which the stator winding coils are placed, connected to the phases according to the star-delta scheme, the stator winding is made six-phase and axially symmetric with the ratio and the number of turns equal to the triangle and stars

, each phase has an equal number of grooves, coils of different phases are stacked in different grooves so that the resulting magnetic flux vectors of adjacent phases form an electric angle of 27-34 °, the phases are connected to a star and a triangle through one to form conclusions that are spaced apart from each other each other at 27-34 ° and interconnected to form phase connection points.

The utility model is illustrated by drawings:

FIG. 1 is a diagram of the claimed electric vehicle drive;

FIG. 2 is a diagram of a stator winding.

The electric transport drive (Fig. 1) consists of an electric energy source 1 (battery), a controlled frequency converter-recuperator 2, consisting of an inverter 3 on IGBT transistors, a microcontroller drive control system 4 and current and voltage sensors 5, and an alternating electric machine current, made in the form of an induction motor 6 with a short - closed rotor.

, на каждую фазу приходится равное число пазов статора, катушки 7 различных фаз уложены в разные пазы так, что результирующие векторы магнитного потока соседних фаз образуют между собой электрический угол φ=27-34°, фазы через одну соединены в звезду 8 и треугольник 9 с образованием выводов 10, отстоящих друг от друга на 27-34° и соединенных между собой с образованием точек 11 подключения фаз.The stator of the motor 6 has, like the prototype, grooves (not shown in Fig.), In which the stator winding coils 7 are connected, connected to phases A. B, C (Fig. 2) according to the scheme star 8 and triangle 9. In this case, the winding the stator is made six-phase and axially symmetric with the ratio of the numbers of turns of triangle 9 and star 8 equal

, each phase has an equal number of stator grooves, coils of 7 different phases are stacked in different grooves so that the resulting magnetic flux vectors of adjacent phases form an electric angle φ = 27-34 °, the phases are connected to a star 8 and a triangle 9 s through one the formation of conclusions 10, spaced from each other by 27-34 ° and interconnected with the formation of points 11 connecting the phases.

Electric transport drive operates as follows.

When braking a vehicle with the declared drive, the asynchronous motor 6 enters the generator mode and the electricity generated by it is supplied to the output of the inverter 3. The control system of the drive 4, in accordance with the readings of the current and voltage sensors 5, switches the inverter 3 to the reverse mode and three-phase electric power coming from the asynchronous engine 6, is rectified, summed and fed to the input of the battery 1, where it is saved by increasing the charge of the latter.

The claimed technical solution provides:

- the possibility of manufacturing an electric motor with a fractional number of phase shifts;

- the ability to adjust the shaft speed by an electronic frequency converter;

- high performance indicators:

- the mechanical characteristic is stable, and the starting torque is maximum and 2-3 times greater;

- with non-rated load, energy efficiency decreases slightly;

- during voltage fluctuations, including a drop several times, it does not “tip over” like a normal blood pressure, but stably continues to work with less power, but with high efficiency;

- the multiplicity of starting currents is reduced from 7 to 4.5;

- critical moment and sudden stop is absent.

Experimentally confirmed:

- increase in specific power by 20-50%;

- less current consumption of 20-50% depending on the mode;

- higher starting torque by 35%;

- lower starting currents by 35%;

- a larger minimum torque of 35%;

- greater maximum torque by 20%;

- an increase of 25-30% in the mileage of electric vehicles, for example, an electric vehicle in one cycle of charging batteries, compared with a drive from a three-phase asynchronous motor with a squirrel-cage rotor.

Based on the foregoing, we can conclude that the task of the utility model — the optimization of the design of the electric transport drive — has been solved, and the claimed technical result — improving the safety of the electric transport drive while improving its efficiency — has been achieved.

Claims (1)

Electric transport drive, including an electric energy source integrated into an electric circuit, a controlled frequency converter-recuperator and an alternating current electric machine made in the form of an asynchronous motor with a short-circuited rotor and stator, in the grooves of which are placed stator winding coils connected to the star-shaped phases a triangle, characterized in that the stator winding is made six-phase and axially symmetric with a ratio of the number of turns of the triangle and the star equal to $$\sqrt{3}$$

, each phase has an equal number of grooves, coils of different phases are stacked in different grooves so that the resulting magnetic flux vectors of adjacent phases form an electric angle of 27-34 °, the phases are connected to a star and a triangle through one to form conclusions that are spaced apart from each other each other at 27-34 ° and interconnected to form phase connection points.

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