CN101079556A - Structure of novel generator stator - Google Patents

Abstract

A novel generator stator structure relates to a stator structure suitable for high-voltage and ultra-high-voltage generators. In existing products, in order to reduce eddy current loss, individual strands must be insulated from each other and transposed in complex shapes along the wire rod. In order to homogenize the electric field and avoid corona, complex measures must be taken in the area of the winding ends. This product includes the stator core (7) and frame (4) stacked by stator punching sheets, the stator winding (1) is wound by a circular cross-section high-voltage cable, and is used to place the stator slot (2) of the stator winding (1) ) is a "sugar gourd string" type, and a cable is worn in each slot of the stator. This product uses cables as stator windings, eliminating the need for turn insulation, interlayer insulation, slot insulation and phase insulation, which saves costs and is easy to operate; concentric windings or distributed windings can be used to reduce harmonics and improve power quality. It is suitable for high-voltage and ultra-high-voltage generators and is also used for wind power generation, maglev trains and diving, submersible motors, etc.

Description

New generator stator structure

technical field

The invention relates to a generator stator structure, in particular to a stator structure suitable for high-voltage and ultra-high-voltage generators.

Background technique

Since the invention of the rotating electrical machine in the 19th century, the main structure and materials used in the electrical machine have not changed substantially. The traditional generator stator structure is composed of stator winding, stator core and frame. The iron core is formed by stacking iron core punches. The stator slots are mostly open slots or semi-closed slots, and the slot shapes are mostly round or pear-shaped. The stator bar is composed of a rectangular cross-section conductor with high electric strength epoxy as the main insulation. An uneven electric field is generated around the rectangular conductor. The electric field strength at the corner is relatively high, while the side is relatively low, so that the conductor is not stressed. all. To reduce eddy current losses, individual strands must be insulated from each other and transposed in complex shapes along the bar. In order to homogenize the electric field and avoid corona, complex measures must be taken in the area of the winding ends (such as transposition). The wire needs to be insulated between turns and layers, and the slot between the wire and the stator slot needs to be insulated. Increased cost and motor volume.

The traditional stator winding adopts a single-layer winding. Although it is equivalent to a full-pitch distributed winding and has a high utilization rate of the stator slot area, the winding pitch cannot be selected arbitrarily, and the ends overlap each other, which is inconvenient for wiring and confusing in structure. For the concentric winding, although the pitch coefficient is equal to 1, the winding coefficient is large, but the harmonic component is large.

Invention content:

The purpose of the invention is to provide a novel stator structure of a high-voltage generator.

The purpose of the invention is achieved in this way:

A new generator stator structure, including stator punching laminated into a stator core (7) and frame (4), the stator winding (1) is wound by a circular cross-section high-voltage cable, used to place the stator winding (1) The stator slots (2) are "candied haws strings" type, and a cable is passed through each slot of the stator.

In the novel generator stator structure, the insulation of the cables of the stator winding adopts uniform insulation or step insulation.

In the novel generator stator structure, the stator windings are concentric windings distributed in layers.

In the novel generator stator structure, the stator winding cable is a single wire or multiple wires or non-twisted strands or twisted strands.

In the novel generator stator structure, the stator winding includes a cable conductor (8), an inner semiconductive layer (9), an insulating layer (10), and an outer semiconductive layer (11).

In the novel generator stator structure, the stator winding (1) is bound by polyester glass strands (6) and then fixed on the binding ring (5) inside the frame.

The advantage that the present invention creates is:

1. The stator structure uses high-voltage cables as stator windings, and the cross-section of the cables is circular, which can generate a uniform electric field, and the external potential of the cables is zero, so there is no need for traditional motor rectangular conductor turn insulation, interlayer insulation, and slot insulation and phase insulation.

2. The multi-layer concentric structure of the stator winding can reduce the harmonic component. The use of distributed windings can reduce the amount of harmonics, improve power quality and performance, and improve stability.

3. The stator winding adopts twisted strands, which solves the problem of eddy current loss.

4. The high-voltage generator with this stator structure can generate high voltage, so the generated electric energy can be directly transmitted over long distances, and the switch, busbar, surge voltage protector, step-up transformer and their corresponding infrastructure on the generator side can be eliminated , so that the overall cost is greatly reduced. At the same time, there is no active and reactive power loss caused by the equipment, which improves the efficiency and benefit of the power plant, and is conducive to the safe, stable and economical operation of the power system.

5. This product uses cables as the stator winding, which saves the turn insulation, layer insulation, slot insulation and phase insulation, which saves costs and is easy to operate; the stator ends are beautiful and organized.

Description of drawings

Figure 1 is a schematic diagram of the product structure.

Figure 2 is the A-A sectional view of the stator structure of this product.

Figure 3 is a schematic diagram of the cable structure of this product.

Fig. 4 is a schematic diagram of stator core laminations in which the stator slot 2 is a "sugar gourd string" type.

Figure 5 is a schematic diagram of phase A of the stator winding of this product.

In the figure: 1-stator winding, 2-stator slot, 3-insulation layer, 4-frame, 5-binding ring, 6-polyester glass strand, 7-stator core, 8-conductor for stator winding of high voltage generator 9 - inner semiconducting layer, 10 - insulating layer, 11 - outer semiconducting layer.

Detailed ways

Example 1:

The stator structure of the new generator includes stator punching sheets stacked to form a stator core 7, and an insulating layer is provided between the stator punching sheets. The stator winding 1 is wound by a high-voltage cable with a circular cross-section. The stator slot 2 for placing the stator winding 1 is a "sugar gourd string" type. The stator winding includes a cable conductor 8, an inner semiconducting layer 9, and an insulating layer 10 , the outer semiconductor layer 11 . The section of the stator winding cable is circular, and the twisted strands can of course also be a single wire or multiple wires or non-twisted strands.

Frame 4 is the main structural part of the high-voltage generator, which has a great influence on the interchangeability of the motor and the uniformity of the air gap. It is generally made of thin-walled castings, and the upper and lower ends of the inner wall are welded with binding rings 5, mainly for fixing polyester glass filaments. Bundle of 6 is used. Since the stator voltage of the high-voltage generator is greatly reduced, the ends of the windings only need to be bound neatly with φ5 polyester glass filament binding ropes and fixed on the binding ring 5 on the machine base 4 to get final product.

The size and specifications of the stator slot 2 are related to the generator voltage. When the voltage is low, a smaller-sized groove can be used and the same specification can be used; when the voltage is higher, a larger-sized groove can be used, and the specifications of the groove can be different, but considering factors such as processing technology, the groove The specifications are generally 1 to 3 types. One cable runs through each slot. Stator windings can adopt a concentric structure and can be distributed in layers. As shown in Fig. 5, it is a schematic diagram of phase A expansion of Z=24, p=1, q=4 single-layer concentric winding.

Stator winding 1 cable outsourcing insulation can adopt uniform insulation or step insulation. When the voltage of the generator is low, it adopts uniform insulation; when the voltage of the generator is high, it adopts step insulation, using thicker insulation in the first few turns of the winding, and the subsequent insulation increases with the number of turns. Increase and gradually increase the thickness of the insulation wrap. This ensures a constant stator tooth width. As shown in Figure 1, the cables are passed through the stator slots to form the windings. The size of the stator winding 1 is determined by the maximum value of the winding voltage and electrical power. The stator winding of this structure does not run from the slot radially to the slot, but a single winding cable passes from one end of the iron core to the other end along the axial direction of the slot, and is transmitted back from one end according to the pitch requirement, reciprocating. , until one group or one phase winding is off the line, avoiding too many cable joints and improving the reliability of operation.

Claims (7)

1. A new type of generator stator structure, including the stator core (7) and frame (4) stacked by stator punching sheets, which is characterized in that: the stator winding (1) is wound by a high-voltage cable with a circular cross-section, and is used to place all The stator slots (2) of the stator winding (1) are of the "candied haws string" type, and a cable is passed through each slot of the stator. 2. The novel generator stator structure according to claim 1, characterized in that: the insulation of the cables of the stator winding adopts uniform insulation or step insulation. 3. The new generator stator structure according to claim 1 or 2, characterized in that: the stator windings are concentric windings or layered distribution. 4. The novel generator stator structure according to claim 1 or 2, characterized in that: the stator winding cable is a single wire or multiple wires or non-twisted strands or twisted strands. 5. The novel generator stator structure according to claim 3, characterized in that: said stator winding cables are twisted strands. 6. The novel generator stator structure according to claim 1, 2 or 5, characterized in that: the stator winding includes a cable conductor (8), an inner semiconducting layer (9), an insulating layer (10), an outer semiconducting layer layer (11). 7. The novel generator stator structure according to claim 1, 2 or 5, characterized in that: the stator winding (1) is bound by polyester glass strands (6) and fixed on the binding ring (5) inside the frame )superior.

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