RU2414791C1 - Modular electrical machine - Google Patents

Abstract

FIELD: electricity.

SUBSTANCE: invention refers to low-speed high-moment electric motors, electric drives and electric generators; it also deals with the design of electric machines with contact rings of any powers - from tenth parts of W to hundreds of kW, and can be used in automation systems as traction controlled and non-controlled electric drives, electric generators, and multi-phase power supplies with electric current. The proposed modular electric machine includes stator the armature core of which consists of isolated electrotechnical steel sheets with high magnetic permeability and has salient poles with coil m-phase winding of armature, each coil of which is arranged on the appropriate salient pole of armature, one per a pole, and rotor containing charged inductor core made of electrotechnical steel sheets with high magnetic permeability; the above inductor has salient poles and coil excitation winding, and each coil of which is arranged on the appropriate salient pole of inductor, one per a pole. Electric connection of excitation winding with source of constant (rectified) voltage is performed through sliding contact by means of brush-and-spring assembly with brushes. When direct (rectified) current flows via excitation winding of inductor, alternating polarity of N - S magnetic inductor poles appears in air gap. At that, there are certain ratios between the number of salient armature poles, number of phases of m-phase armature winding, number of salient poles in armature module phase, number of modules and number of salient poles of inductor.

EFFECT: high energy data, high specific torque moment on the shaft in electric motor mode and high specific power in electric generator mode of modular electric machine owing to better use of its useful capacity, and available brush-and-contact assembly allows feeding the excitation winding of inductor with considerable direct current and thus increasing electromagnetic and heat loads, as well as smoothly controlling the output parameters of electric machine; besides, there are no restrictions regarding the design of the above high-duty machines with large overall dimensions, as well as their assembly in comparison to similar electromagnetic machines.

6 cl, 5 dwg

Description

The invention relates to the field of electrical engineering, in particular to low-speed high-torque electric motors, electric drives and electric generators, for the design of electric machines with slip rings of any power - from tenths of a W to hundreds of kW, and can be used in automation systems, as traction controlled and uncontrolled electric drives, electric generators, multiphase power supplies with electric current.

Known designs of synchronous machines with a three-phase winding of the armature and the excitation winding of the inductor (Ivanov-Smolensky A.V. Electric machines: Textbook for high schools. - M .: Energy, 1980. P. 490 ÷ 513). Anchor performed neyavnopolyusnym carrying the three-phase distributed raznoimennopolyusnuyu p-period moving coil or inductor performed salient neyavnopolyusnym bearing raznoimennopolyusnuyu p-period moving excitation winding. Electrical communication with the power source is carried out directly and using a brush-contact unit. Synchronous machines are most widely used, in which the armature winding is connected to the load (in generator mode) or to a three-phase voltage source (in motor mode) directly, and the inductor excitation winding is connected to slip rings and connected to a constant voltage source through sliding contacts using brushes . Low-power synchronous machines can also be made in reverse design, when electrical contact with the field winding is carried out directly, and with the armature winding through the brush-contact assembly. The disadvantage of these electric machines is the difficulty of performing a distributed winding of the armature, which has less reliability compared to the coil concentrated winding of the armature. In addition, synchronous machines of this class in the engine mode have small starting torques, and special measures are used to start them.

Known synchronous motor (AS USSR SU No. 1345291 A1, IPC H02K 19/02, bull. No. 38, 1987, author A.F. Shevchenko), containing a stator with a three-phase winding and an active rotor with alternating polarity of the poles, the stator is made with pronounced poles, and the number of poles of the stator Z _S and rotor Z _{R are} made in the ratio Z _R = Z _S ± k, where Z _S = 3 · k, and k = 1, 2, 3, ..., stator winding coils belonging to one phase and located at the poles shifted by 360 el. city., included counter. The disadvantage of the described synchronous electric motor is the presence of a stator with only a three-phase winding of the armature, which reduces the possible applications of this device.

Known adopted for the prototype electric machine with a two-pack inductor (options) (patent RU No. 2356154 C1, IPC H02K 19/06, H02K 19/20, authors: Zakharenko AB, Chernukhin VM), containing an anchor with a lined core a multiphase coil winding placed on its pole projections, a cylindrical two-pack inductor comprising a lined core with pole protrusions, the armature is single-packet, the armature winding consists of coils, each of which is located on a separate tooth, the excitation is carried out by a ring-shaped winding, located laid between the two cores of the inductor, the teeth of the first and second cores of the inductor are placed relative to each other so that the axis of each tooth of the first core coincides with the axis of each groove of the second core of the inductor, the electric machine with a two-pack inductor consists of modules - "elementary machines", the number of teeth of the armature Z ₁ = m · Z _1m · s, the number of teeth on any core of the inductor Z _2N = Z _2S = (m · Z _1m ± 1) · c, where m = 2, 3, 4, 5, 6 ... is the number of winding phases anchors, Z _1m = 1, 2, 3, 4 ... - the number of teeth of the anchor per one module, on which the coils are located and windings of the armature phase, c = 1, 2, 3, 4 ... the number of modules, the electrical connection between the rotating winding of an electric machine with a two-pack inductor and an external electrical circuit is carried out by means of brushes and slip rings. The disadvantage of the described electric machine is the worst use of its useful volume compared with the claimed invention.

The aim of the present invention is to improve energy performance, increase the specific moment on the shaft of an electric machine with slip rings due to the better use of its useful volume.

The presence of the brush-contact unit allows you to power the excitation coil of the inductor with a significant constant (rectified) current and, thereby, increase electromagnetic and thermal loads, as well as smoothly control the output parameters of the electric machine. In addition, there are no restrictions on the performance of these machines with large capacities and with large dimensions, as well as their assembly in comparison with similar magnetoelectric machines.

The objective of the present invention is the optimal choice of the number of pronounced pole of the armature when performing concentrated on them m-phase coil winding of the armature and the number of clearly marked poles of the inductor when performing focused on them coil winding excitation of the inductor, fed through a brush-contact node constant (rectified) electric current modular electric machine.

The technical result of the present invention is the provision of high energy performance, a large specific torque on the shaft in the electric motor mode and a large specific power in the electric generator mode of a modular electric machine.

In order to achieve the objective and the technical result of the invention, the electric machine consists of modules. The module is an “elementary machine” as part of an electric machine. The stator contains an anchor core laced from insulated sheets of electrical steel with high magnetic permeability and has pronounced poles and an m-phase coil winding of the armature, each coil of which is placed on the corresponding distinct pole of the armature, one per pole, the rotor contains lined from sheets of electrical steel with high magnetic permeability core of the inductor with pronounced poles and a coil excitation coil, each coil of which is placed on the corresponding clearly cut the connected pole of the inductor, one at a time, creating a direct (rectified) electric current during the passage of the magnetic current of the inductor with the alternating polarity of the N-S magnetic poles formed in the air gap. The inductor core is mounted on the sleeve or directly on the shaft (for small rotor diameters). The electrical connection of the field winding with a source of constant (rectified) voltage is through a sliding contact using a brush-spring assembly with brushes. In order to increase the manufacturability of winding operations and increase the groove fill factor, pronounced inductor poles can be detachable and attached directly to the sleeve or shaft (for small shaft diameters). In addition, the rotor can be made with claw-shaped poles and an annular field winding of the inductor. Executions of a modular electric machine with an external armature and an internal inductor, with an internal armature and an external inductor are possible.

The inductor excitation winding through contact rings and brushes can be connected to an independent source of constant (rectified) voltage, as well as to the output ends of the phases of the m-phase armature winding through the m-phase diode bridge.

When using a modular electric machine as a synchronous electric motor, power supply to the armature winding by electric current can be carried out:

- from an m-phase source of alternating voltage of constant frequency,

- from an m-phase variable voltage source of adjustable frequency,

- from a constant voltage source by means of a controlled inverter supplying a sinusoidal voltage to the phases of the armature winding, depending on the readings of the rotor angular position sensor to achieve maximum torque. In this case, the electric current of the inductor can be powered directly from a constant (rectified) voltage source or from the output ends of the phases of the m-phase armature winding through the m-phase diode bridge.

When using a modular electric machine as a direct current electric motor with independent excitation, the armature winding can be supplied with electric current by rectangular voltage pulses from the electronic switch according to a certain algorithm depending on the readings of the rotor angular position sensor to achieve maximum torque. In this case, the field winding of the inductor is connected directly to an independent source of constant (rectified) voltage and receives electric power from it. In the case of using a modular electric machine as a direct current electric motor with sequential excitation, the field coil of the inductor is connected to the output ends of the phases of the m-phase armature winding through the m-phase diode bridge and receives power from it with a rectified electric current.

The invention is illustrated by the figures of the drawings:

figure 1, figure 3 - examples of the invention in the form of cross sections of a modular electric machine with an active rotor,

figure 2, figure 4 - examples of the invention in the form of connection diagrams of coils of m-phase windings of the armature when the modular electric machine is in electric motor mode and vector diagrams of phase currents of the armature,

5 is a General view of a modular electric machine with an external armature and an internal inductor.

In accordance with the present invention, to obtain the best energy performance at the maximum specific moment on the shaft of a modular electric machine, the number of pronounced armature poles Z _1p , the number of phases of the m-phase armature winding m = 3, 4, 5, 6, ..., the number of distinct poles in the phase of the armature module Z _1c , the number of modules c = 1, 2, 3, 4, ... and the number of pronounced poles of the inductor Z _2P are related by equalities (1) and (2):

moreover, with m = 3, 5, 7, 9, ... the number of pronounced poles in the phase of the armature module Z _1c = 1, with m = 4, 6, 8, 10, ... the number of pronounced poles in the phase of the armature module Z _1c = 2 , the coil windings in the phase of the armature module at Z _1c = 2 are magnetically interconnected, the corresponding coil windings of the armature phase of different modules are magnetically opposed, the beginning of the phases of the armature winding can belong to coils focused on the pronounced poles of one of the modules, either the corresponding coils of any module, coil windings of the armature belonging to e single phase and one or different modules can be interconnected in series, parallel or form series-parallel electrical circuits, the ends of the phases of the winding modules, or the ends of the phases of the armature windings can be short-circuited, or the ends of the same phases, but different modules can be interconnected shortly and connected to the input ends of the m-phase diode bridge.

The module M _{Z is} conveniently denoted as an irreducible fraction M _Z = Z _1P / Z _2P , showing the ratio of the number of pronounced poles of the armature and the number of explicit poles of the inductor in the "elementary machine".

It should be noted that the direction of rotation of the inductor in the operating mode of a modular electric machine by an electric motor is opposite to the direction of rotation of the circular magnetic field of the armature created by a multiphase system of alternating electric currents flowing along the armature winding. This circumstance should be taken into account when calculating the magnetic losses in a machine during its design.

Figure 1 ÷ 4 presents examples of the invention in accordance with equalities (1) and (2). The position of the vectors of the phase currents of the armature in the vector diagram, the directions of the electric currents flowing along the coils of the armature of the armature of the coils of the 6-phase armature winding of the armature shown in FIG. 2, and the position of the core of the inductor relative to the core of the armature of a modular electric machine in motor mode, shown in FIG. .1 correspond to the same moment in time. The position of the vectors of the phase currents of the armature in the vector diagram, the directions of the electric currents flowing along the coils of the armature of the armature of the coils of the coils of the 5-phase armature winding shown in FIG. 4, and the position of the core of the inductor relative to the core of the armature of a modular electric machine in motor mode, shown in FIG. .3 correspond to the same moment in time. Figure 2 presents the connection diagram of the coils of the 6-phase armature winding for a 2-module electric machine, in which all the coils of the same phase, but of different modules, are connected to each other in series. Figure 4 presents the connection diagram of the coils of the 5-phase armature winding for a 3-module electric machine, in which all the coils of the same phase, but of different modules, are connected in parallel with each other.

Consider the design of a modular electric machine with an internal inductor and an external armature (figure 1, figure 3, figure 5). Anchor core 2 remagnetized with a high frequency has pronounced poles 3 and is made of lined from insulated sheets of electrical steel with high magnetic permeability. It is pressed into the housing 1, which can be made of steel or aluminum alloy. An open case is also possible. On each of the pronounced poles 3 of the core 2 of the armature is placed a coil of the winding 4 of the armature. Coil winding 4 anchors are made of a winding copper wire or a winding copper bus. They are isolated from the yoke and pronounced poles 3 of the core 2 anchors with case insulation. Using the bearings 11, the shaft 5 and the bearing shields 10, the inductor is positioned relative to the armature. The shaft 5 is made of steel. The active part of the inductor consists of a core 7 charged with electrical steel with high magnetic permeability, with pronounced poles 8, mounted on a sleeve 6 made of metal. At the pronounced poles 8 of the inductor, there is a coil winding 9 of the inductor excitation, the coils of which are located on adjacent poles, are magnetically connected to each other made of a winding copper wire or a winding copper bus. An insulating non-conductive sleeve with contact rings 12 and the output ends of the inductor excitation winding 9 connected to them is connected to the shaft 5, the electrical connection of which with a constant (rectified) voltage source is made through a sliding contact using a brush-spring assembly with brushes 13. In order to improve manufacturability performing winding work and increasing the fill factor of the groove, pronounced poles 8 of the inductor can be made detachable from a material with high magnetic permeability by the bridge. In this case, they are attached directly to the sleeve 6, made of a material with high magnetic permeability. In this case, with small rotor diameters, the shaft 5 and the sleeve 6 can be a single part made of a material with high magnetic permeability.

The modular electric machine can operate in motor and generator modes.

Consider the motor mode (figure 1 ÷ 5). An alternating voltage is applied to the phases of the winding 4 of the armature, an alternating current flows through the winding, which induces a time-varying MDS of the armature. Figure 2 shows a vector diagram of the phase currents of the armature and the connection diagram of the coils of the 6-phase armature winding for a 2-module machine. Figure 4 shows a vector diagram of the phase currents of the armature and the connection diagram of the coils of the 5-phase armature winding for a 3-module machine. Symmetric multiphase voltages applied to the terminals of these windings change in time, and the current vectors in the vector diagrams rotate counterclockwise in the xy coordinate axes. The directions of electric currents shown in the connection diagrams of the coils of the armature windings correspond to the point in time when the phase currents in the vector diagrams are projected onto the ordinate axis. The coils of the winding 4 of the anchor are called a letter denoting belonging to the corresponding phase, and a number denoting the number of the pronounced pole 3 of the core 2 of the armature. For example, coil A1 is a phase A coil located on the first distinct pole 3 of the core 2 of the armature. When alternating electric armature 4 windings flow through the winding coils, the pronounced poles 3 of the armature, being magnetized, form time-varying southern magnetic poles “S” and northern magnetic poles “N” with variable MDS anchors. When excited poles 8 of the inductor are excited by direct (rectified) current flowing through the excitation winding 9 of the inductor through the brushes 13 and contact rings 12 from the source of constant (rectified) voltage and back to it, in the air gap, southern magnetic poles "S" and the north magnetic poles "N" of the inductor with alternating polarity. Due to the interaction of the variable MDS of the armature with the constant of the MDS of the inductor, unidirectional torque is applied to the rotor. In accordance with the present invention, in one period of a change in the magnetic field, the rotor rotates into two pole divisions of the inductor, i.e. by 2 · t _2P , where t _2P = 360 ° / Z _2P . As a result of this, when the supply voltage is applied to the armature winding with a frequency f (Hz), the rotor moves with a synchronous rotation speed n = 120 · f / Z _2P (r / min). The direction of rotation of the rotor in figure 1 and figure 3 is shown by an arrow with the letter "n".

Consider the generator mode (figure 1 ÷ 5). A constant (rectified) voltage is supplied to the field winding 9 of the inductor from the power source. When the rotor rotates with an external source of torque with a rotational speed n, the constant magnetic flux of the inductor created by the direct current flowing through the excitation coil 9 of the inductor through the contact rings 12 and brushes 13 from the source of direct (rectified) voltage and back to it, penetrating the air gap and clearly expressed pole 3 of the armature from the side of the inductor, then from the side of the armature, creates in the pronounced poles of the 3 armature an alternating magnetic flux, inducing a variable EMF in the coils of the winding 4 of the armature. In the coils of the winding 4 anchors belonging to the same phase, at the same time, the same EMF are induced, which, when combined, form the EMF of this phase. If the external circuit - the load circuit - is closed, then an m-phase electric current flows through winding 4 of the armature, electric power is given to the consumer.

Claims (6)

1. A modular electric machine, consisting of modules, the number of which is c = 1, 2, 3, 4, ..., and containing an anchor with a lined core, a multiphase coil winding of the armature and a cylindrical inductor, characterized in that the stator contains a lined core of the armature with clearly expressed poles and coil m-phase winding of the armature, each coil of which is located on the corresponding pronounced pole of the armature one at a time on the pole, the rotor contains a lined core of the inductor with distinct poles and coil winding, each I coil which is placed on the corresponding clearly pronounced pole of the inductor one at a time on the pole, the electrical connection of the field coil with a constant (rectified) voltage source is made through a sliding contact using a brush-spring assembly with brushes, the number of pronounced armature poles Z _1P , the number of phases m -phase winding of the armature m = 3, 4, 5, 6, the number of pronounced poles in the phase of the module of the armature Z _1c , the number of modules c and the number of pronounced poles of the inductor Z _2p are related by equalities (1) and (2):

moreover, with m = 3, 5, 7, 9, ... the number of pronounced poles in the phase of the armature module Z _1c = 1, with m = 4, 6, 8, 10, ... the number of pronounced poles in the phase of the armature module Z _1c = 2 , the coil coils in the phase of the armature module at Z _1c = 2 are magnetically interconnected according to each other, the corresponding coil coils of the armature phase of the different modules are magnetically connected in opposite directions. 2. The modular electric machine according to claim 1, characterized in that the anchor is located outside, the inductor inside. 3. The modular electric machine according to claim 1, characterized in that the inductor is located outside, the anchor inside. 4. The modular electric machine according to claim 2 or 3, characterized in that the rotor is made with claw-shaped poles and an annular field winding of the inductor. 5. The modular electric machine according to claim 1, characterized in that the field winding of the inductor through the contact rings and brushes is connected to an independent source of constant (rectified) voltage. 6. The modular electric machine according to claim 1, characterized in that the field winding of the inductor through contact rings and brushes is connected to the output ends of the phases of the m-phase armature winding through the m-phase diode bridge.

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