Collector monitoring system

A collector monitoring system is disclosed. In one embodiment, the collector monitoring system includes: a sensor connected to an interior surface of a dynamoelectric machine housing, the sensor for sensing a condition of a collector during operation of a dynamoelectric machine; and a diagnostic system operably connected to the sensor, the diagnostic system configured to: obtain data about the condition of the collector from the sensor; compare the data about the condition of the collector with a predetermined condition threshold; and provide an indicator of a collector fault in response to the data about the condition of the collector exceeding the predetermined condition threshold.

BACKGROUND OF THE INVENTION

The subject matter disclosed herein relates to a collector monitoring system. Specifically, the subject matter disclosed herein relates to a system for monitoring the condition of collectors used in a dynamoelectric machine (e.g., an electrical generator, electrical motor, etc.), to provide early indication of collector faults.

Conventional dynamoelectric machines include brushes, positioned on a stationary frame, for providing an exciting electrical current during operation of the dynamoelectric machine. The electrical current is directed from the brushes to collectors (e.g., collector rings, or slip rings) coupled to the rotor of the dynamoelectric machine. The collectors then transfer the electrical current to the rotor windings for use in generating power within the dynamoelectric machine. The collectors conduct the electrical current by continuously contacting the brushes during rotation. However, this continuous contact between the brushes and the collectors can be disrupted by: changes in brush pressure due to the wearing of a spring in the brush assembly, vibrations of the dynamoelectric machine shaft, wear to the brush contact surface and/or degradation of the collector film between the collector and the brushes. The disruption of contact between the brushes and the collectors can cause diminished performance in the dynamoelectric machines, and degradation of the brushes and collectors.

Degradation of the brushes and collectors can be minimized, but not eliminated, by establishing and maintaining an optimum electrical contact between the brushes and the collectors. Maintaining the optimum electrical contact depends on a variety of characteristics of the brushes and the collectors, including: maintaining an optimum brush pressure on the collector, lubricating the collector using a collector ring film, maintaining the collector surface condition, and providing the brush with a proper contour fit to the collector. However, maintaining the optimum electrical contact between the brushes and collectors can be challenging. If the electrical contact between the brushes and collectors is too low, sparking and/or arcing may occur. Sparking and arcing significantly increase the likelihood of machine failure due to collector flashovers.

Conventionally, human operators visually inspect brushes and collectors of a dynamoelectric machine to monitor for any collector flashover events. Typically, the dynamoelectric machine is fully operational when the operator inspects the brushes and collectors for any faults. As a result, the human operator is limited in their ability to inspect the dynamoelectric machine for operational faults. Furthermore, prevention of collector flashovers is dependent on the frequency of inspection of the brushes and/or the collectors.

BRIEF DESCRIPTION OF THE INVENTION

A collector monitoring system is disclosed. In one embodiment, the collector monitoring system includes: a sensor connected to an interior surface of a dynamoelectric machine housing, the sensor for sensing a condition of a collector during operation of a dynamoelectric machine; and a diagnostic system operably connected to the sensor, the diagnostic system configured to: obtain data about the condition of the collector from the sensor; compare the data about the condition of the collector with a predetermined condition threshold; and provide an indicator of a collector fault in response to the data about the condition of the collector exceeding the predetermined condition threshold.

A first aspect of the invention includes a collector monitoring system having: a sensor connected to an interior surface of a dynamoelectric machine housing, the sensor for sensing a condition of a collector during operation of a dynamoelectric machine; and a diagnostic system operably connected to the sensor, the diagnostic system configured to: obtain data about the condition of the collector from the sensor; compare the data about the condition of the collector with a predetermined condition threshold; and provide an indicator of a collector fault in response to the data about the condition of the collector exceeding the predetermined condition threshold.

A second aspect of the invention includes an apparatus having: a dynamoelectric machine including: a machine housing; and a collector coupled to a rotor within the machine housing; and a collector monitoring system operably connected to the machine housing, the collector monitoring system including: a sensor connected to an interior surface of the machine housing, the sensor for sensing a condition of the collector during operation of the dynamoelectric machine; and a diagnostic system operably connected to the sensor, the diagnostic system configured to: obtain data about the condition of the collector from the sensor; compare the data about the condition of the collector with a predetermined condition threshold; and provide an indicator of a collector fault in response to the data about the condition of the collector exceeding the predetermined condition threshold.

A third aspect of the invention includes a method for sensing a condition of a collector during operation of a dynamoelectric machine, performed using a collector monitoring system. The method includes: obtaining data about the condition of the collector from a sensor connected to an interior surface of a dynamoelectric machine housing; comparing the data about the condition of the collector with a predetermined condition threshold; and providing an indicator of a collector fault in response to the data about the condition of the collector exceeding the predetermined condition threshold.

DETAILED DESCRIPTION OF THE INVENTION

As described herein, aspects of the invention relate to a collector monitoring system. Specifically, as described herein, aspects of the invention relate to a system for monitoring the condition of collectors used in a dynamoelectric machine, to provide early indication of collector faults.

In contrast to conventional approaches, aspects of the invention include a system for monitoring the condition of collectors used in dynamoelectric machines (e.g., an electrical generator, electrical motor, etc.), to provide early indication of collector faults. In particular, aspects of the invention include a collector monitoring system that may aid in preventing collector flashovers within the dynamoelectric machine by providing early indications of collector operational degradation.

Turning toFIG. 1, a schematic depiction of an environment2including a collector monitoring system4and a cross-sectional view of a dynamoelectric machine6is shown according to embodiments of the invention. Dynamoelectric machine6can include a rotor shaft8, and one or more collectors10coupled to rotor shaft8via collector insulating sleeves11. Dynamoelectric machine6can include any conventional dynamoelectric device, including but not limited to, a generator, a motor or any other driving or driven machine known in the art. Rotor shaft8and collectors10may be positioned radially internal of brushes12of dynamoelectric machine6. As shown inFIG. 1, brushes12are connected to a stationary frame13, such that a plurality of brushes12may contact a single collector10. Rotor shaft8, collectors10, insulating sleeves11, brushes12and stationary frame13are included in a machine housing14of dynamoelectric machine6. During operation of dynamoelectric machine6, collectors10may continuously contact brushes12in order to transfer an electric current from brushes12to collector10. The electrical current may then be transferred from the collector10to rotor windings (not shown) for generating power within the dynamoelectric machine6. Dynamoelectric machine6can include other components found in a conventional dynamoelectric machine. These components are omitted from the description for clarity.

The collector monitoring system4may include a sensor16positioned within the dynamoelectric machine6, and a diagnostic system18operably connected to the sensor16(e.g., via wireless, hardwire, or other conventional means). In some embodiments, diagnostic system18can include a plurality of sensors16, as shown in phantom inFIG. 1. In some embodiments, sensor16may be positioned within the machine housing14of dynamoelectric machine6and may be configured to sense a condition (e.g., a physical condition) of collector10during operation of dynamoelectric machine6. Sensor16may sense a physical condition of collector10either continuously, or intermittently. Furthermore, sensor16may be configured to provide data pertaining to the physical condition of one or more collectors10, during operation of dynamoelectric machine6, to diagnostic system18. In some embodiments, sensor16may specifically sense the environmental conditions (e.g., temperature) surrounding the collector10in order to sense the physical condition of collector10, as discussed below.

As shown, sensor16can be connected to an interior surface20of machine housing14. In some cases, sensor16can be directly coupled to the interior surface20of machine housing14via any conventional means (e.g., one or more bolts, screws, complementary slots, pins, adhesives, lock joints, etc). In an embodiment, sensor16may be positioned within machine housing14separated from the brushes12, collector10and rotor shaft8, in order to prevent physical interference with the moving components (e.g., rotor shaft8and/or collector10) of the dynamoelectric machine6. The position of sensor16within machine housing14can be dependent on the sensor type (as discussed below), the power required to operate sensor16and/or the operating power generated by dynamoelectric machine6. In one embodiment, sensor16may be configured to continuously sense the physical condition of a plurality of collectors10during operation of dynamoelectric machine6. In other embodiments, the collector monitoring system4can include a plurality of sensors16connected to the interior surface20of machine housing14. In some embodiments, the plurality of sensors16may each be configured to continuously sense a distinct collector10of dynamoelectric machine6. In this case, each sensor16may provide data to the diagnostic system18about the physical condition of each distinct collector10during operation of dynamoelectric machine6. In another embodiment, a plurality of sensors16may be configured to continuously sense a single collector10of dynamoelectric machine6, and the plurality of sensors16can each provide distinct data about the physical condition of collector10during operation of dynamoelectric machine6. Data from the sensor16may be collected by the collector monitoring system4and can be processed by the diagnostic system18.

In some embodiments, the sensor16may include, but is not limited to, a light sensor configured to continuously sense an amount of light emitted within the machine housing14during operation of dynamoelectric machine6. In these embodiments, light sensor16may be connected to a particular location of interior surface20in order to provide a substantially unobstructed visual perception of collector10. The substantially unobstructed visual perception of collector10means the sensing path (e.g., visual perception) of light sensor16does not have to be completely unobstructed, but can be partially obstructed while sensing a condition of collector10. In another embodiment, the collector monitoring system4can include, but is not limited to, a plurality of sensors16, where the plurality of sensors16may be a variety of distinct conventional sensor types. More specifically, in these embodiments, sensor16may include one or more of: an ozone sensor configured to sense the ozone level within the machine housing10of the dynamoelectric machine6; an acoustic sensor configured to sense sound frequency signals within the machine housing10of the dynamoelectric machine6; an ultrasonic sensor configured to sense inaudible signals within the machine housing10of the dynamoelectric machine6; an infrared sensor configured to sense a temperature within the machine housing10of the dynamoelectric machine6; an ultraviolet sensor configured to sense an electromagnetic radiation level within the machine housing10of the dynamoelectric machine6; or any other conventional sensor configured to sense the physical condition of a collector10during operation of the dynamoelectric machine6.

Also illustrated inFIG. 1, collector monitoring system4can include a power source22configured to provide power for diagnostic system18and/or sensor16. Power source22may include any conventional power supply system known in the art. Power source22can be connected to diagnostic system18and/or sensor16via hardwire, or any other conventional means, to provide power. In some embodiments, diagnostic system18may also include an output device24configured to provide indicators about a physical condition of collector10during operation of dynamoelectric machine6, as described below. In some embodiments, the indicators provided by the output device24can include an indication that collector10is not operating correctly within dynamoelectric machine6and may result in a failure of dynamoelectric machine6. Output device24may include, but is not limited to, an interface, such as a graphical user interface (GUI) or other conventional interface, for providing one or more of: an auditory indicator (e.g., siren), a visual indicator (e.g., light, print out), or other conventional indicator known in the art. In an alternative embodiment, diagnostic system18may include a plurality of output devices24configured to provide indicators about a condition of collector10during operation of dynamoelectric machine6. In other embodiments, each of the plurality of output devices24may be configured to provide distinct indicators about the physical condition of collector10during operation of dynamoelectric machine6.

Turning toFIG. 2, a schematic diagram of collector monitoring system4is shown according to embodiments of the invention. In the Figures, it is understood that similarly numbered components may function in a substantially similar fashion. Redundant explanation of these components has been omitted for clarity. As shown inFIG. 2, diagnostic system18(within collector monitoring system4) can include a receiver module26, a storage device28, a data compare module30and an indicator module32. Receiver module26and storage device28are communicatively connected to data compare module30and data compare module30is communicatively connected to indicator module32. Receiver module26can be configured to obtain data from sensor16about the physical condition of collector10. More specifically, receiver module26is configured to continuously obtain data from sensor16and may temporarily store the data from sensor16prior to transmitting the data to the data compare module30. Receiver module26may be configured as any conventional data processing module capable of receiving, temporarily storing and transmitting/forwarding data within a data processing system (e.g., computer system).

Also illustrated inFIG. 2, diagnostic system18may include a storage device28. Storage device28may store predetermined condition threshold data29(as shown in phantom) for one of more collectors10. In another embodiment, predetermined condition threshold data29may be stored on an external device and may be obtained and temporarily stored on storage device28. The predetermined condition threshold data29can include data defining a desired operational range, or threshold for the collector10. The predetermined condition threshold data29can define this desired operational range or threshold according to the particular type of sensor16used to obtain data about the collector10during operation of the dynamoelectric machine6. If the data obtained from one or more sensors16indicates operation of a collector10outside of the range (or above/below the threshold) of the predetermined condition threshold data29, the collector10may be operating in an undesirable state, and could have a fault. In some cases, this fault could indicate a risk of failure of the collector10, which could require repair and/or shutdown of the dynamoelectric machine6.

The diagnostic system18may also include a data compare module30configured to obtain data from the receiver module26and storage device28and compare the data obtained therein. More specifically, data compare module30may be configured to obtain the data from receiver module26and storage device28, compare the data from receiver module26and storage device28, and determine whether the data obtained from receiver module26exceeds the predetermined condition threshold data29. Data compare module30may also be configured to transmit an indicator to the indicator module32of diagnostic system18. Indicator module32may be configured to obtain the indicator from data compare module30and may provide output device24with an indicator about a physical condition of the collector10.

Turning toFIG. 3, with continuing reference toFIG. 2, a flow chart illustrating a process in determining a condition of collector10during operation of the dynamoelectric machine6is shown according to embodiments of the invention. For example, process P1can include obtaining data about the condition of collector10during operation of the dynamoelectric machine6. The data about the condition of collector10may be obtained by receiver module26from sensor16, as shown inFIG. 2. In an embodiment of the invention, the data about the condition of collector10may be data directly dependent on the configuration type of sensor16. For example, sensor16may include, but is not limited to, a light sensor and may provide data indicating the amount of light emitted within the machine housing14during operation of dynamoelectric machine6. In the example embodiment, the light emitting within the machine housing may be a result of collector10not operating correctly within dynamoelectric machine6(e.g., arcing, sparking) In another embodiment, sensor16may include an ozone sensor, and may provide data pertaining to a level of ozone detected within the machine housing14during operation of dynamoelectric machine6. In an alternative embodiment, sensor16may include an acoustic sensor, and may provide data about sound frequency signals within the machine housing14during operation of dynamoelectric machine6. In a further embodiment, sensor16may include an ultrasonic sensor, and may provide data pertaining to inaudible signals detected within housing12during operation of dynamoelectric machine6. In another embodiment, sensor16may be an infrared sensor capable of providing data about a temperature within machine housing14during operation of dynamoelectric machine6. In an alternative embodiment, sensor16may include an ultraviolet sensor, and may provide data about a level of electromagnetic radiation emitted within machine housing14during operation of dynamoelectric machine6.

After the data about the condition of collector10is obtained, in process P2(shown in phantom as optional) the data about the condition of collector10is grouped based upon the data configuration and/or the type of sensor16. Process P2may include grouping the data obtained by sensor16when, for example, a variety of sensors16are implemented in collector monitoring system4and each sensor16provides data about the condition of collector10. For example, collector monitoring system4may include, but is not limited to, two light sensors and a single infrared sensor. Receiver module26may obtain the data (e.g., amount of light emitted, temperature) individually from each sensor16, and may group the data from each of the two light sensors, prior to sending the data to compare module28.

Following the grouping of data in process P2, process P3can include comparing the data about the condition of collector10to predetermined condition threshold data29stored in storage device28. Process P3may be executed by data compare module30(as shown inFIG. 2). Data compare module30can obtain the data about the condition of collector10from receiver module26and can simultaneously obtain the predetermined condition threshold data29from storage device28. Data compare module30can then determine the type of data obtained, based on the sensor16type(s), and may compare the data received to the predetermined condition threshold data29. The predetermined condition threshold data29can be based upon the type of sensor16sensing the physical condition of the collector10. For example, sensor16of collector monitoring system4may include, but is not limited to, an infrared sensor for providing data about a temperature within machine housing14during the operation of dynamoelectric machine6. In this example, data compare module30may obtain data about a temperature within machine housing14from sensor16. Data compare module30may then determine that the data received is from an infrared sensor, and may compare the data obtained to infrared sensor data included in the predetermined condition threshold data29obtained from storage module28. More specifically, data compare module30may obtain data indicating that the temperature within machine housing14is 80 degrees Celsius. In this specific example, data compare module30may compare this data to the predetermined condition threshold data29for the temperature within machine housing14that indicates a data temperature threshold of 50 degrees Celsius.

After process P3, process P4may include determining whether the data about the condition of collector10exceeds the predetermined condition threshold data29. That is, process P4may determine that collector10is operating outside a desired operational range or threshold, and could have a fault. Process P4may also be executed by data compare module30(as shown inFIG. 2). Continuing the example used in process P3, data compare module30may compare the data obtained from receiver26that indicates the temperature within machine housing14is 80 degrees Celsius, to the predetermined condition threshold data29of 50 degrees Celsius. In this example, data compare module30may then determine that data obtained from receiver module26has exceeded the predetermined operation threshold data29(e.g., 80° C.>50° C.). From this determination, data compare module30can also determine that collector10has a fault and may be causing the temperature within machine housing14to exceed the predetermined operation threshold data29. As a result of collector10outside a desired operational range or threshold, machine failure (e.g., collector flashover) may occur, causing damage to the dynamoelectric machine, which may lead to shutdown.

After determining the data about the condition of collector10exceeds the predetermined threshold data, process P5can include providing an indicator of a potential fault (or failure) of collector10. Process P5is executed once indicator module32(as shown inFIG. 2) obtains an indicator from data compare module30, indicating the condition of collector10exceeds the predetermined threshold data29. Indicator module32may utilize output device24(as shown inFIG. 2) to provide a user with an indication that data about the condition of a collector10has exceeded the predetermined threshold data, as determined in process P4, and collector10has a fault and/or may cause dynamoelectric machine6to fail (e.g., temporary damage, power down, etc.). Continuing the example used in processes P3and P4, in process P5, indicator module32may obtain the indicator from data compare module30indicating that the temperature within machine housing14has exceeded the threshold temperature as defined by the predetermined condition threshold data29(e.g., 80° C.>50° C.). In this example, once indicator module32obtains the indicator from data compare module30, indicator module32may then convey a message to the user, via output device24, that the condition of collector10has exceeded the predetermined operation threshold (e.g., 80° C.>50° C.), and as a result, may cause machine failure (e.g., collector flashover), causing damage to the dynamoelectric machine, which may lead to shutdown.

Following process P5, process P6(shown in phantom as optional) can include utilizing indicator module32to provide an indicator signal of the collector10fault and provide an indicator that collector10requires maintenance before continuing operation of dynamoelectric machine6. More specifically, the indicator signal of the collector10fault further provides instructions to perform at least one of an inspection or a replacement of the collector10. Process P6may also prompt indicator module32to utilize output device24(as shown inFIG. 2) for providing a user with an indication about the condition of collector10.

Turning toFIG. 4, a schematic depiction of a combined cycle power plant100is shown according to embodiments of the invention. Combined cycle power plant100may include, but is not limited to, a gas turbine102operably connected to dynamoelectric machine6. Dynamoelectric machine6may be connected to collector monitoring system4, via sensor16(not shown), ofFIG. 1or other embodiments described herein. Dynamoelectric machine6and gas turbine102may be mechanically coupled by a shaft104, which may transfer energy between a drive shaft (not shown) of gas turbine102and dynamoelectric machine6. Also shown inFIG. 4a heat exchanger106is operably connected to gas turbine102and a steam turbine108. Heat exchanger106may be fluidly connected to both gas turbine102and a steam turbine108via conventional conduits (numbering omitted). Heat exchanger106may include a conventional heat recovery steam generator (HRSG), such as those used in conventional combined cycle power systems. As is known in the art of power generation, HRSG may use hot exhaust from gas turbine102, combined with a water supply, to create steam which is fed to steam turbine108. Steam turbine108may optionally be coupled to a second dynamoelectric machine6(via a second shaft104) which may be connected to collector monitoring system4ofFIG. 1or other embodiments described herein. It is understood that dynamoelectric machines4and shafts104may be of any size or type known in the art and may differ depending upon their application or the system to which they are connected. Common numbering of the dynamoelectric machines and shafts is for clarity and does not necessarily suggest these dynamoelectric machines or shafts are identical.

Turning toFIG. 5, a schematic depiction of a combined cycle power plant200is shown according to a further embodiment of the invention. In the embodiment, a single shaft combined cycle power plant200may include a single dynamoelectric machine6coupled to both a gas turbine202and a steam turbine204via a single shaft104. Single dynamoelectric machine6may be connected to collector monitoring system4ofFIG. 1or other embodiments described herein.

The embodiments ofFIGS. 1-3, as described above, relate to monitoring a condition of one or more collector(s)10during operation of the dynamoelectric machine6. In a further embodiment, and as shown inFIG. 1, collector monitoring system4can be configured to monitor brushes12during operation of the dynamoelectric machine6. More specifically, collector monitoring system4can be configured to monitor a condition of brushes12, via sensor16, during operation of the dynamoelectric machine6in order to provide an indicator of a brush fault. As similarly described above with reference toFIG. 1, sensor16may be positioned within machine housing14, separated from the brushes12, collector10and rotor shaft8, in order to prevent physical interference with the moving components (e.g., rotor shaft8and/or collector10) of the dynamoelectric machine6. More specifically, sensor16can be positioned in a particular location of machine housing14in order to provide a substantially unobstructed sensing path of brush12. The substantially unobstructed sensing path for sensor16does not have to be completely unobstructed, but can be partially obstructed while sensing a condition of brush12. In the further embodiment, sensor16can be any conventional sensor, as described above, capable of sensing a condition of brushes12during operation of the dynamoelectric machine6. For example, sensor16can include, but is not limited to, an infrared sensor, configured to sense a temperature of brush12during operation of dynamoelectric machine6. In the example embodiment, and as similarly described with reference toFIG. 3, collector monitoring system4can obtain data about the condition of brushes12from infrared sensor16(P1). The data obtained by sensor16can be the temperature of brush12during operation of the dynamoelectric machine6. Similar steps (P2-P6) are taken in the example embodiment, as described above, in order to provide an indicator of a brush fault. Redundant explanations of the steps have been omitted for clarity. Furthermore, in the example embodiment many components (sensors16, diagnostic system18, etc.) of collector monitoring system4may be substantially similar to those shown and described with reference toFIGS. 1-3. It is understood that these similar components may function in a substantially similar fashion as described with reference to the other Figures herein. Redundant explanation of these elements has been omitted for clarity.

In another embodiment, the invention provides a method for sensing a condition of a collector10during operation of a dynamoelectric machine6, performed using a collector monitoring system4. The method includes: obtaining data about the condition of the collector10from a sensor16connected to an interior surface20of a dynamoelectric machine housing14, comparing the data about the condition of the collector10with a predetermined condition threshold29, and providing an indicator of a collector fault in response to the data about the condition of the collector10exceeding the predetermined condition threshold29. In this embodiment, the invention can further include obtaining data about the condition of the collector10from a plurality of sensors16connected to the interior surface20of the dynamoelectric machine housing14. Furthermore in this embodiment, the obtaining of the data about the condition of the collector10includes at least one of: sensing an ozone level within the dynamoelectric machine housing14using an ozone sensor, sensing an amount of light emitted within the dynamoelectric machine housing14using a light sensor, sensing sound frequency signals within the dynamoelectric machine housing14using an acoustic sensor, sensing inaudible signals within the dynamoelectric machine housing14using an ultrasonic sensor, sensing a temperature within the dynamoelectric machine housing14using an infrared sensor, or sensing an electromagnetic radiation level within the dynamoelectric machine housing14using an ultraviolet sensor. Additionally in this embodiment, the providing of the indicator of the collector fault can include providing instructions to perform at least one of an inspection or a replacement of the collector10.

In a further embodiment, the invention provides a system, including: a turbine including a shaft, a dynamoelectric machine coupled to the turbine via the shaft; and a collector monitoring system operably connected to the dynamoelectric machine. The collector monitoring system including: a sensor connected to an interior surface of a dynamoelectric machine housing, the sensor for sensing a condition of a collector during operation of the dynamoelectric machine. The system also including: a diagnostic system operably connected to the sensor, the diagnostic system configured to: obtain data about the condition of the collector from the sensor, compare the data about the condition of the collector with a predetermined condition threshold data, and provide an indicator of a collector fault in response to the data about the condition of the collector exceeding the predetermined condition threshold data.