CN106253516B - A kind of double axis excitation rotor of steam turbo generator winding construction - Google Patents

Abstract

The invention discloses a double-shaft excitation turbogenerator rotor winding structure with three sets of symmetrical windings on the rotor, slots are evenly slotted on the surface of the rotor and the windings are put in, the rotor is a two-pole hidden pole structure, and there are three A set of evenly distributed and symmetrical windings, the axes of the three sets of windings are 120° apart in space; the three sets of windings are drawn out through 6 slip rings and corresponding carbon brushes. When the excitation current is applied to the two sets of windings of the biaxial excitation turbogenerator, the third set of windings is short-circuited as a damping winding; the biaxial excitation turbogenerator can be used to study the excitation system of the biaxial excitation turbogenerator The control strategy can also be used to study the influence of dual-shaft excitation turbogenerator on power system stability.

Description

A Rotor Winding Structure of a Double-shaft Excitation Turbogenerator

technical field

The invention belongs to the technical field of excitation winding structure and energization mode of a double-shaft excitation turbogenerator, and particularly relates to a rotor winding structure of a double-shaft excitation turbogenerator with three sets of symmetrical windings on the rotor.

Background technique

After a serious fault in the power system causes the ordinary generator to stop, the dual-axis excitation turbogenerator can still continue to run. The power angle of the dual-axis unidirectional excitation can reach 180°, and the dual-axis positive and negative alternating excitation can run asynchronously; The high stability of the excitation turbogenerator determines its unique position in the power system. It can be used for highly reliable power supply to key users and special important places; in the event of a large-scale power outage, it can provide power for the follow-up treatment of the accident. In addition, it can also operate in a state of deep phase advance, and absorb a large amount of reactive power while outputting active power; the dual-shaft excitation turbogenerator is of great significance to improving the safe operation level of the power system and ensuring reliable power supply in critical areas.

Contents of the invention

In order to study the operating characteristics and stable operation capability of the dual-shaft excitation turbogenerator, the invention provides a rotor winding structure of the dual-shaft excitation turbogenerator with three sets of symmetrical windings on the rotor.

The technical scheme adopted in the present invention is:

A dual-shaft excitation turbogenerator rotor winding structure with three sets of symmetrical windings on the rotor. Slots are slotted on the surface of the rotor and the windings are placed. The rotor is a two-pole hidden pole structure, and there are three sets of evenly distributed and symmetrical windings in the rotor slots. The axes of the three sets of windings have a mutual difference of 120° in space; the three sets of windings are respectively drawn out through 6 slip rings and corresponding carbon brushes.

Further, each set of windings in the slot of the rotor is respectively provided with an inflow end and an outflow end.

Further, when the engine is uniaxially excited, one set of windings is connected to the DC power supply through slip rings and carbon brushes, and the other two sets of windings are short-circuited through slip rings and carbon brushes.

Further, when the engine is biaxially excited, the two sets of windings are connected to the DC power supply through slip rings and carbon brushes. By changing the size and direction of the current flowing into the windings, the position of the synthetic excitation magnetic field can be changed within the spatial range of 0-360°. The third set of windings Short-circuit through slip rings and carbon brushes as a damping winding.

Furthermore, when the first set and the second set of windings are respectively supplied with no-load excitation currents i _f1 and i _f2 in the positive direction, the air-gap fundamental wave magnetomotive forces generated are F _f1 and F _f2 respectively, and the two work together to generate The magnitude of the synthetic air gap fundamental wave magnetomotive force satisfies:

Among them, F _f1 and F _f2 are respectively when the first set and the second set of windings are fed with the no-load excitation current i _f1 and i _f2 ,

The amplitude of the air gap fundamental wave magnetomotive force generated.

Furthermore, when the first set of windings is fed with the no-load excitation current i _f1 in the positive direction, the air gap fundamental wave magnetomotive force generated is F _f1 , and the second set of windings is fed with the no-load excitation current i _f2 in the opposite direction, When the air-gap fundamental wave magnetomotive force generated is F _f2 , the synthetic air-gap fundamental wave magnetomotive force generated by the joint action of the two satisfies:

Among them, F _f1 and F _f2 are the magnitudes of the air gap fundamental wave magnetomotive force generated when the first set and the second set of windings are fed with no-load excitation currents i _f1 and i _f2 respectively.

The beneficial effects of the present invention are:

When the power grid is disturbed, the dual-shaft excitation turbogenerator can realize the change of the magnitude and direction of the excitation magnetic field by adjusting the magnitude and direction of the current in any two sets of windings, so that the electromagnetic quantity and electromechanical quantity inside the generator are favorable The system is developing in a stable direction.

The dual-shaft excitation turbogenerator can operate in a deep phase-advancing state. In the case of excess reactive power in the grid, it can not only deliver sufficient active power to the grid, but also absorb excess reactive power; The ability of phase operation can make up for the lack of ability of ordinary generators to operate in phase, and prevent the power grid from overvoltage when the power consumption is low.

The air-gap fundamental wave magnetomotive force of the dual-axis excitation turbogenerator can be 1.732 times of the air-gap fundamental wave magnetomotive force of the single-axis excitation at most.

There are three sets of uniformly distributed and symmetrical windings on the rotor of the dual-axis excitation turbogenerator. During the dynamic process of the system, the two sets of windings apply excitation current to provide an excitation magnetic field, and the third set of windings is short-circuited to act as a damping winding, which can further improve Stability of generators during dynamic processes.

The dual-shaft excitation turbogenerator can realize dynamic compensation of reactive power in the grid, respond quickly and in real time to the reactive power demand of the grid, and the reactive power compensation characteristic has continuity.

The dual-shaft excitation turbogenerator can be used to study the actual structure of the motor and the coordinated operation characteristics of the generator network and the excitation control strategy affected by various nonlinear factors. Horizontal excitation control provides new support.

Description of drawings

Fig. 1 is a schematic diagram of a two-dimensional interface of a 10kW dual-shaft excitation turbogenerator rotor designed according to the present invention.

Figure 2 shows the structure of the collector ring and carbon brush holder on the rotating shaft.

Figure 3 shows the air-gap flux density waveform and the air-gap flux density fundamental wave component when a set of windings of the dual-shaft excitation turbogenerator rotor is applied with a no-load excitation current of 7.4A.

Figure 4 shows the air-gap flux density waveform and the air-gap flux density fundamental wave component when the two sets of windings of the dual-shaft excitation turbogenerator are fed with 7.4A no-load excitation current according to the specified positive direction.

Figure 5 shows the air-gap magnetic density waveform when the first set of windings of the dual-shaft excitation turbogenerator is fed with a 7.4A no-load current in the positive direction, and the second set of windings is fed with a 7.4A no-load current excitation current in the reverse direction and air-gap magnetic density fundamental wave components.

Detailed ways

The present invention will be described in further detail below in conjunction with the accompanying drawings.

The invention provides a dual-shaft excitation turbogenerator rotor winding structure with three sets of windings on the rotor. Grooves are slotted on the surface of the rotor 1 and the windings 2 are placed. The rotor is a two-pole hidden pole structure, and there are three sets of windings in the rotor slots. Evenly distributed and symmetrical windings, the axes of the three sets of windings are 120° apart in space; the three sets of windings are drawn out through 6 slip rings and corresponding carbon brushes. The structure of the stator winding is the same as that of the traditional motor.

Each set of windings in the rotor slot is respectively provided with an inflow end and an outflow end.

When the engine is uniaxially excited, one set of windings is connected to the DC power supply through slip rings and carbon brushes, and the other two sets of windings are short-circuited through slip rings and carbon brushes.

According to the dynamic operating conditions of the dual-axis excitation turbogenerator, when the generator is biaxially excited, any two sets of windings are connected to the DC power supply, and the position of the synthetic excitation magnetic field is 0-360° by changing the size and direction of the current flowing into the winding. The range is changed, and the third set of windings is short-circuited as a damping winding.

Example:

According to the technical scheme of the present invention, a 10kW double-shaft excitation turbogenerator is designed. The rotor cross section of the generator is shown in Figure 1. The rotor 1 is a two-pole hidden pole structure, and the three sets of windings 2 on the rotor are different in space. 120°; the three sets of windings of the rotor adopt a double-layer distributed short-distance stacked winding structure, the number of slots per pole and each phase is 8, and the winding pitch is 20, which can effectively improve the air gap magnetic field when the three-phase excitation current acts alone or together Waveform; Area 3 and Area 4 indicated by the dotted line of the rotor in Figure 1 are the inflow end and outflow end of the first set of rotor windings, Area 5 and Area 6 are the inflow end and outflow end of the second set of rotor windings, Area 7 and Area 8 It is the inflow end and outflow end of the third set of windings of the rotor.

The three sets of windings of the rotor are connected through 6 slip rings and carbon brushes. Figure 2 shows the structure of slip rings and carbon brush holders. When single-axis excitation, only one set of windings is connected to the power supply through slip rings and carbon brushes, and the other two sets of excitation windings are connected to short-circuit switches through slip rings and carbon brushes to form a closed loop; Connected to the power supply, the third set of windings are shorted through slip rings and carbon brushes to form a closed loop.

When the dual-shaft excitation turbogenerator has only one set of windings to apply 7.4A no-load excitation current, the air-gap flux density waveform and the air-gap flux-density fundamental wave component when the iron core is saturated are ignored, as shown in Figure 3, the air-gap flux-density fundamental The amplitude value is 0.3655T. When the two sets of windings of the dual-axis excitation turbogenerator are fed with 7.4A no-load excitation current according to the specified positive direction, the air-gap flux density waveform and the air-gap flux density fundamental wave component when the iron core is saturated are not considered. As shown in Figure 4, the amplitude of the fundamental wave of the air-gap magnetic density is 0.3655T. Since the fundamental magnetomotive force is proportional to the fundamental magnetic density generated by it in the linear case, the magnetic potential corresponding to the above magnetic density satisfies the formula Among them, F _f1 and F _f2 are the magnitudes of the air gap fundamental wave magnetomotive force generated when the first set and the second set of excitation windings are fed with no-load excitation currents i _f1 and i _f2 respectively. When the first set of windings of the dual-shaft excitation turbogenerator is supplied with a 7.4A no-load excitation current in the positive direction, and the second set of windings is supplied with a 7.4A no-load excitation current in the reverse direction, the resultant air gap when the core is saturated is not included The magnetic density waveform and the air gap magnetic density fundamental wave components are shown in Figure 5, and the air gap magnetic density fundamental wave amplitude is 0.6324T. Since the fundamental magnetomotive force is proportional to the fundamental magnetic density generated by it in the linear case, the magnetic potential corresponding to the above magnetic density satisfies the formula Among them, F _f1 and F _f2 are the magnitudes of the air gap fundamental wave magnetomotive force generated when the first set and the second set of excitation windings are fed with no-load excitation currents i _f1 and i _f2 respectively.

As mentioned above, the present invention has been described in detail, obviously, as long as it does not deviate from the invention points and effects of the present invention, the deformations that are obvious to those skilled in the art are all included in the protection scope of the present invention .

Claims (5)

1. A double-shaft excitation turbogenerator rotor winding structure with three sets of symmetrical windings on the rotor, which is characterized in that slots are slotted on the rotor surface and the windings are placed, the rotor is a two-pole hidden pole structure, and the rotor slots There are three sets of evenly distributed and symmetrical windings, the axes of the three sets of windings are 120° apart in space, and the three sets of windings are drawn out through 6 slip rings and corresponding carbon brushes. 2 . The rotor winding structure of a dual-shaft excitation turbogenerator according to claim 1 , wherein each set of windings in the rotor slots is provided with an inflow end and an outflow end respectively. 3 . 3. The rotor winding structure of the dual-axis excitation turbogenerator according to claim 1, wherein when the generator is biaxially excited, the two sets of windings are connected to the DC power supply through slip rings and carbon brushes, and by changing the current flowing into the winding The size and direction of the synthetic excitation magnetic field can be changed within the spatial range of 0-360°, and the third set of windings is short-circuited through slip rings and carbon brushes as damping windings. 4. The double-shaft excitation turbogenerator rotor winding structure according to claim 1, characterized in that, when the first set and the second set of windings are fed into the no-load excitation current i _f1 and i _f2 respectively according to the positive direction, The generated air-gap fundamental wave magnetomotive forces are F _f1 and F _f2 respectively, and the synthetic air-gap fundamental wave magnetomotive force generated by the joint action of the two satisfies: Among them, F _f1 and F _f2 are the magnitudes of the air gap fundamental wave magnetomotive force generated when the first set and the second set of windings are fed with no-load excitation currents i _f1 and i _f2 respectively. 5. The rotor winding structure of the dual-shaft excitation turbogenerator according to claim 1, characterized in that, when the first set of windings is independently fed with the no-load excitation current i _f1 in the positive direction, the generated air gap fundamental wave magnetic motion When the potential is F _f1 , and the second set of windings are separately fed into the no-load excitation current i _f2 in the opposite direction, the air-gap fundamental wave magnetomotive force is F _f2 , and the synthetic air-gap fundamental wave magnetomotive force generated by the joint action of the two is Satisfy: Among them, F _f1 and F _f2 are the magnitudes of the air gap fundamental wave magnetomotive force generated when the first set and the second set of windings are fed with no-load excitation currents i _f1 and i _f2 respectively.