JPH11187619A - Method and device for cooling stator of rotary electric machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize efficient in-machine ventilation cooling by supplying gas to a cooling pipe from the cooling medium take-in ports of the end turn part of a stator winding wire trough a transportation pipe and guiding it to a heat exchanger from the cooling medium take-out ports of an end turn part on an opposite side through a different transportation pipe. SOLUTION: A cooling medium gas 10a obtained by shunting a part of cooling medium gas 7 which circulatively ventilated in a machine is pressurized and is supplied to a cooling pipe 13 from the cooling medium take-in ports 12 provided for a stator winding wire end turn part 5a via the transportation pipe 11a, so that it does not mix with cooling medium gas 7. When the cooling medium gas 10a pressurized by a compressor 9 is blown into the cooling pipe 13, the stator winding wire 5 is forcibly cooled. A cooling medium gas take-out ports 15 are provided on the opposite side of the cooling medium gas take-in ports 12 and cooling medium gas 10a is collected from there in the cooling pipe 13.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for cooling a stator winding of a rotary electric machine such as a turbine generator, and more particularly, to a method of compressing and blowing gas to a cooling pipe provided in the stator winding. TECHNICAL FIELD The present invention relates to a method and an apparatus for cooling a stator of a rotating electric machine, which enable more efficient in-machine ventilation cooling.

[0002]

2. Description of the Related Art In a rotary electric machine, for example, a turbine generator for power generation, a cooling medium is circulated through the machine to cool main parts such as a rotor and a stator. FIG. 6 is a schematic diagram showing a cross-sectional structure of a main part of the turbine generator and a state of an in-machine ventilation path.

[0003] In FIG. 6, a rotor winding 2 is housed and arranged in a rotor 1 which is rotated by a prime mover (not shown). The rotor 1 is excited when a field current is supplied to the rotor winding 2 from an exciter 3 attached to the shaft end.

On the other hand, a stator winding 5 is housed in the stator 4, and the rotating magnetic field generated by the excited rotor 1 interlinks with the stator winding 5, so that the stator winding 5 An alternating current is induced.

As described above, the rotor winding 2 and the stator winding 5
Generates heat, which are cooled by the rotor fan 6 and radiated to the outside air through the heat exchanger 8.
In such an in-machine ventilation cooling structure, while it is necessary to maintain a proper flow rate of the cooling medium gas 7 to the rotor 1 and the stator 4, the cooling medium gas is required to increase the capacity of the generator. 7, the required air volume is increasing more and more.

[0006]

SUMMARY OF THE INVENTION By the way, a rotating electric machine,
For example, in the case of a turbine generator, air was initially used as a cooling medium gas, but with the increase in the capacity of the generator, the required airflow has been increased. On the other hand, windage loss, that is, hydrodynamic agitation loss increases with an increase in the required air volume, but hydrogen gas having a smaller molecular weight than air has been used as a cooling medium gas in order to suppress such loss.

However, in the conventional hydrogen-cooled generator using a cooling medium gas, it is necessary to separately install a maintenance and inspection facility for explosion and the like. However, it is pointed out that there are various restrictions.

[0008] In recent years, under the circumstances described above, demands for increasing the capacity of an air-cooled generator have been increasing, while demands for a more compact and higher-efficiency machine have also increased. Therefore, in order to reduce the windage loss due to the cooling medium gas ventilation, it is necessary to suppress the required flow rate of the cooling medium gas itself. In particular, in an air-cooled power generator, since air having a higher molecular weight than hydrogen gas is used as a cooling medium gas, it is necessary to take measures to avoid an increase in the temperature of the cooling medium gas due to windage damage.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has been developed for a rotating electric machine which enables efficient in-machine ventilation cooling by compressing and blowing gas to a cooling pipe provided in a stator winding. An object of the present invention is to provide a stator cooling method and device.

[0010]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a method and an apparatus for cooling a stator of a rotating electric machine by the following means. An invention corresponding to claim 1 is a stator cooling method for a rotating electric machine that cools a stator winding by a cooling medium gas that circulates through the machine,
A part of a cooling medium gas that circulates and ventilates inside the machine is divided and pressurized to a cooling pipe adjacent to the stator winding in the stator core slot and disposed over the entire length of the stator winding,
In order not to be mixed with a part of other in-machine cooling medium gas that circulates and passes other than the stator winding, it is supplied to the cooling pipe from the cooling medium intake at the end turn part of the stator winding through the transport pipe,
The cooling medium outlet of the opposite end turn is guided to the heat exchanger through another transport pipe.

According to a second aspect of the present invention, there is provided a method for cooling a stator of a rotary electric machine in which a stator winding is cooled by a cooling medium gas circulating in the machine, wherein the stator winding is adjacent to the stator winding in a stator core slot. And, a cooling medium gas having a large heat capacity different from that of the cooling medium gas to be circulated and ventilated in the machine is pressurized in a separate system to a cooling pipe arranged over the entire length of the stator winding, and circulated outside the stator winding. The cooling medium is supplied from the cooling medium inlet at the end turn section of the stator winding to the cooling pipe through the transport pipe so that it does not mix with some of the other in-machine cooling medium gas that is ventilated. It is characterized in that it is led from the outlet to the heat exchanger through another transport pipe.

According to a third aspect of the present invention, in the stator cooling method for a rotating electric machine according to the second aspect of the present invention, an outlet temperature of the cooling medium gas is detected, and a supply flow rate of the cooling medium gas is determined based on the detected temperature. And amplifies the arithmetic processing signal and uses it as a rotational speed control signal of a compressor for pressurizing the cooling medium gas.

According to a fourth aspect of the present invention, there is provided a stator cooling device for a rotary electric machine for cooling a stator winding by a cooling medium gas circulating in the machine, wherein the stator winding is adjacent to the stator winding in a stator core slot. And a cooling pipe disposed over the entire length of the stator winding, a compressor for diverting and pressurizing a part of the cooling medium gas circulating through the machine, and a cooling medium gas compressed by the compressor. A first transport pipe leading to the cooling pipe through a cooling medium inlet provided at one end turn portion of the stator winding, and a cooling medium gas outlet provided at an end turn portion opposite to the stator winding. And a second transport pipe for guiding the extracted cooling medium gas to the heat exchanger.

According to a fifth aspect of the present invention, there is provided a stator cooling device for a rotating electric machine for cooling a stator winding by a cooling medium gas circulating through the machine, wherein the stator winding is adjacent to the stator winding in a stator core slot. A cooling pipe arranged over the entire length of the stator winding, a compressor for pressurizing a cooling medium gas having a large heat capacity of a different type from a cooling medium gas circulating through the machine in a separate system, and A first transport pipe for guiding the compressed cooling medium gas to the cooling pipe through a cooling medium inlet having one end turn section of the stator winding, and an end turn section opposite to the stator winding. A second transport pipe for guiding the cooling medium gas taken out through the cooling medium gas outlet to the heat exchanger.

According to a sixth aspect of the present invention, in the stator cooling device for a rotating electric machine according to the fifth aspect of the present invention, a temperature sensor is provided at an outlet of the cooling medium gas, and the cooling medium gas detected by the temperature sensor is provided. A central processing unit for arithmetically processing a rotation speed control signal to be supplied to a power supply device for driving the compressor based on the temperature; a voltage amplifier for amplifying an output signal of the central processing unit; and an output signal amplified by the voltage amplifier. And a controller for providing a rotation speed control signal of the compressor to a power supply device of the compressor.

In the method and the apparatus for cooling a stator of a rotating electric machine according to the first and fourth aspects of the present invention, a cooling pipe pressurized by a compressor on a cooling pipe provided on a stator winding is provided. Since the medium gas is forcibly blown, an appropriate required air volume can be maintained and adjusted. As a result, the cooling medium gas that circulates through the entire machine can be directed to the cooling of the rotor and stator core other than the stator windings, and the circulating air flow can be reduced as a whole, and the circulating air flow can be reduced. , And hydrodynamic mechanical loss such as windage loss can be reduced.

According to a second aspect of the present invention, there is provided a method and an apparatus for cooling a stator of a rotating electric machine, wherein a cooling medium gas is circulated in the machine to cool the rotor and the stator. Since it is isolated in a separate system from the medium gas, it is possible to use a gas with a large heat capacity as a cooling medium gas from the standpoint of cooling the stator winding with a relatively high heat load. Can be suppressed,
Therefore, the temperature distribution of the stator winding can be suppressed to a low level.

Further, in a method and an apparatus for cooling a stator of a rotating electric machine according to the invention according to claims 3 and 6,
A cooling medium gas having a large heat capacity, that is, a cooling medium having excellent cooling characteristics, is used for a cooling pipe of the stator winding, and a temperature rise of the cooling medium gas is detected and the number of rotations of a compressor that pressurizes and supplies the gas is determined. With constant control, the cooling performance of the cooling pipe can be corrected. As a result, for example, when the generator output fluctuates, the required airflow required for stator cooling can be maintained and corrected to an appropriate value each time.

[0019]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic configuration diagram showing a first embodiment for describing a method and an apparatus for cooling a stator of a rotating electric machine according to the present invention, and FIG. 2 is a sectional view taken along the line AA in FIG. In the following, the same parts as those in the schematic view showing the cross-sectional structure and the in-machine ventilation of the conventional rotary electric machine shown in FIG. 6 as an example will be described with the same reference numerals.

In FIGS. 1 and 2, the stator winding 5 housed in an axial slot provided on the inner peripheral surface of the stator 4 protrudes from the stator ends 4a and 4b on both sides of the stator and is fixed. The child winding end turn portions 5a and 5b are formed.
Also, cooling pipe groups 14 a, which constitute the cooling pipes 13 over the entire length of the stator winding so as to be adjacent to both sides of the stator winding 5,
14b are arranged in pairs.

The compressor 9 pressurizes the cooling medium gas 10a, which is a part of the cooling medium gas 7 circulating through the machine, and pressurizes the cooling medium gas 10a via the transport pipe 11a so as not to be mixed with the cooling medium gas 7. The cooling medium is supplied to a cooling pipe 13 from a cooling medium inlet 12 provided in the winding end turn portion 5a. The cooling medium gas 10a pressurized by the compressor 9 is
Is blown, the stator winding 5 is forcibly cooled.

The cooling pipe 13 is provided with a cooling medium gas outlet 15 on the opposite side of the cooling medium gas inlet 12, from which the cooling medium gas 10a is recovered.

Here, for example, when the cooling medium gas 10a is supplied from one stator end 4a and recovered from the other stator end 4b, the temperature distribution of the cooling medium gas 10a is directed toward the stator end 4a. Accordingly, the stator winding 5 also exhibits a temperature distribution as indicated by a dotted line in FIG. Therefore, the cooling medium group 10a supplies the cooling medium gas 10a from the stator end 4a side and collects the cooling medium gas 10a from the stator end 4b side, whereas the cooling pipe group 14b performs cooling from the stator end 4b. Supply medium gas 10a,
It is configured to be collected from the stator end 4a side.

As a result, as shown by the solid line in FIG. 3, the temperature distribution of the stator winding 5 is leveled, and it is possible to meet the demand for cooling the stator winding 5 uniformly. The cooling medium gas 10a that has become high temperature by cooling the stator winding 5 is recovered as a high-temperature gas from the cooling medium gas outlet 15, but is circulated through the surrounding machine to cool the parts other than the stator winding 5. The cooling medium gas is guided to the heat exchanger 8 via the transport pipe 11b so as not to be mixed with the cooling medium gas to be cooled, and is supplied as the cooling medium gas 7 in the machine after being cooled to a predetermined temperature.

As described above, in the first embodiment of the present invention, the cooling pipe 13 is provided on the stator winding 5 and the cooling pipe 1 is provided.
Since the stator winding 5 is cooled by forcibly blowing the cooling medium gas from the compressor 8 provided outside the machine 3 to cool the stator winding 5, an appropriate required air volume can be maintained and adjusted. Thereby, the cooling medium gas circulating through the entire machine can be directed to the cooling of the rotor and the stator core other than the stator winding, and the circulating air flow can be reduced as a whole. As a result, the amount of circulating air in the machine can be suppressed, and hydrodynamic mechanical loss such as windage can be suppressed low.

FIG. 4 is a schematic configuration diagram showing a second embodiment for explaining a stator cooling method and apparatus for a rotating electric machine according to the present invention. The same components as those in the first embodiment are the same. The description is omitted by attaching the reference numerals, and only different points will be described here.

In FIG. 4, the cooling medium gas 10b recovered from the cooling medium outlet 15 provided in the stator winding end turn portions 5a and 15b of the stator winding 5 is a cooling medium gas circulating in the machine. Using a different type of gas from 7,
This is pressurized by the compressor 9 and supplied to the cooling pipe 13 via the transport pipe 11a. The cooling medium gas 10b is supplied to the cooling pipe 1
3, the stator winding 5 is forcibly cooled in the course of the ventilation, and is recovered as a high-temperature gas from the transport pipe 11b, and is transferred to a heat exchanger 16 different from the heat exchanger 8 for cooling the cooling medium gas 7 circulating through the machine. After being cooled to a predetermined temperature, a closed loop that returns to the compressor 9 is circulated.

As described above, since the cooling medium gas 10b is separated from the cooling medium gas 7 for cooling the rotor 1 and the stator 4 by circulating the air inside the machine, the cooling medium gas 10b has a relatively high heat load. From above, the cooling medium gas 10 is cooled.
For b, a gas having a large heat capacity such as SF ₆ gas (sulfur hexafluoride gas) can be used. This allows
The temperature rise of the cooling medium gas 10b can be suppressed,
Therefore, the temperature distribution of the stator winding 5 can be suppressed to a low level.

Therefore, the temperature distribution of the stator winding 5 can be suppressed to a low level. Further, the cooling performance of the stator winding 5 is limitedly improved by adjusting the performance of the heat converter 16 and the compressor 9 without changing the equipment structure of the cooling medium gas 7 that circulates through the machine. be able to.

FIG. 5 is a schematic structural view showing a third embodiment for explaining a method and an apparatus for cooling a stator of a rotating electric machine according to the present invention. The same components as those in the first and second embodiments are shown. Are denoted by the same reference numerals and description thereof is omitted, and only different points will be described here.

In the third embodiment, a temperature sensor 17 for detecting the temperature of the cooling medium gas 10b is provided at the cooling medium gas outlet 15 as shown in FIG. Input to the arithmetic unit 18. The central processing unit 18 calculates an appropriate supply flow rate of the coolant gas 10b based on the temperature detected by the temperature sensor 17 each time.
After being amplified by the controller and input to the controller unit 20,
Power supply device 21 for driving compressor 9 as a rotation speed control signal
To give.

With this configuration, the cooling medium gas 1
By controlling the rotation speed of the compressor 9 reflecting the detected temperature of 0b, the flow rate of the cooling medium gas 10b can be adjusted in real time, and the cooling performance of the stator winding 5 can be constantly adjusted to an appropriate value.

[0033]

As described above, according to the present invention, the cooling performance of the stator winding can be improved by compressing and blowing the gas to the cooling pipe provided in the stator winding. A method and an apparatus for cooling a stator of a rotating electric machine can be provided.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing a first embodiment of a method and an apparatus for cooling a stator of a rotating electric machine according to the present invention.

FIG. 2 is a sectional view taken along the line AA of FIG. 1;

FIG. 3 is a characteristic curve diagram showing a temperature distribution of a stator winding in the embodiment.

FIG. 4 is a schematic configuration diagram showing a second embodiment of a method and an apparatus for cooling a stator of a rotating electric machine according to the present invention.

FIG. 5 is a schematic configuration diagram showing a third embodiment of a method and an apparatus for cooling a stator of a rotating electric machine according to the present invention.

FIG. 6 is a schematic diagram showing a cross-sectional structure of a main part of a conventional rotary electric machine and a state of an in-machine ventilation path.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Rotor 2 ... Rotor winding 3 ... Exciter 4 ... Stator 4a, 4b ... Stator end 5 ... Stator winding 5a, 5b ... Stator winding end turn part 6 Rotor fan 7 Coolant gas 8 Heat exchanger 9 Compressor 10a, 10b Coolant gas 11a, 11b Transport pipe 12 Coolant gas inlet 13 Cooling Pipes 14a, 14b Cooling pipe group 15 Coolant gas outlet 16 Heat exchanger 17 Temperature sensor 18 Central processing unit 19 Voltage amplifier 20 Controller unit 21 Power supply unit

Claims (6)

[Claims] 1. A stator cooling method for a rotating electric machine, wherein a stator winding is cooled by a cooling medium gas circulating in the machine, wherein the stator winding is adjacent to the stator winding in a stator core slot. A part of the cooling medium gas that circulates and blows the inside of the machine is divided and pressurized to the cooling pipe arranged over the entire length of the line,
In order not to be mixed with a part of other in-machine cooling medium gas that circulates and passes other than the stator winding, it is supplied to the cooling pipe from the cooling medium intake at the end turn part of the stator winding through the transport pipe,
A method for cooling a stator of a rotating electric machine, wherein the cooling medium is guided from a cooling medium outlet of an opposite end turn section to a heat exchanger through another transport pipe. 2. A stator cooling method for a rotating electric machine in which a stator winding is cooled by a cooling medium gas circulating through the machine, wherein the stator winding is adjacent to a stator winding in a stator core slot. A cooling medium gas having a large heat capacity different from that of the cooling medium gas that circulates through the inside of the machine is pressurized in a separate system into the cooling pipes that are arranged over the entire length of the line, and other in-machine cooling medium that circulates and vents other than the stator windings Supply the cooling medium from the cooling medium inlet at the end turn section of the stator winding through the transport pipe to the cooling pipe so that it does not mix with a part of the gas, and transport it separately from the cooling medium outlet at the opposite end turn section. A stator cooling method for a rotating electric machine, wherein the stator is guided to a heat exchanger through a tube. 3. An outlet temperature of the cooling medium gas is detected, a supply flow rate of the cooling medium gas is calculated based on the detected temperature, and the calculation processing signal is used as a rotation speed control signal of a compressor for pressurizing the cooling medium gas. 3. The method for cooling a stator of a rotating electric machine according to claim 2, wherein the method is used. 4. A stator cooling device for a rotating electric machine for cooling a stator winding by a cooling medium gas circulating in the machine, wherein the stator winding is adjacent to the stator winding in a stator core slot. A cooling pipe arranged over the entire length of the wire, a compressor for diverting and pressurizing a part of a cooling medium gas that circulates and flows through the inside of the machine, and a cooling medium gas compressed by the compressor for one of the stator windings A first transport pipe leading to the cooling pipe through a cooling medium inlet provided at an end turn portion of the first transport pipe;
A second transport pipe for guiding a cooling medium gas taken out from a cooling medium gas outlet provided at an end turn portion on the opposite side of the stator winding to a heat exchanger. Child cooling device. 5. A stator cooling device for a rotary electric machine for cooling a stator winding by a cooling medium gas circulating in the machine, wherein the stator winding is adjacent to the stator winding in a stator core slot. A cooling pipe arranged over the entire length of the line, a compressor for pressurizing a cooling medium gas having a large heat capacity of a different type from a cooling medium gas for circulating and ventilating the inside of the machine in a separate system, and a cooling medium gas compressed by the compressor. A first transport pipe leading to the cooling pipe through a cooling medium inlet at one end turn of the stator winding, and a cooling medium gas outlet at an end turn on the opposite side of the stator winding. Second to guide the extracted coolant gas to the heat exchanger
A stator cooling device for a rotating electric machine, comprising: 6. A temperature sensor at an outlet of the cooling medium gas,
A central processing unit that arithmetically processes a rotation speed control signal to be supplied to a power supply device that drives the compressor based on the cooling medium gas temperature detected by the temperature sensor; a voltage amplifier that amplifies an output signal of the central processing unit; 6. The stator cooling device for a rotating electric machine according to claim 5, further comprising a controller for supplying an output signal amplified by the voltage amplifier to a power supply device of the compressor as a rotation speed control signal of the compressor.