US20150364978A1 - Electric Machine - Google Patents
Electric Machine Download PDFInfo
- Publication number
- US20150364978A1 US20150364978A1 US14/391,970 US201414391970A US2015364978A1 US 20150364978 A1 US20150364978 A1 US 20150364978A1 US 201414391970 A US201414391970 A US 201414391970A US 2015364978 A1 US2015364978 A1 US 2015364978A1
- Authority
- US
- United States
- Prior art keywords
- rotor
- stator
- electric machine
- switching
- machine according
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
Images
Classifications
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02K—DYNAMO-ELECTRIC MACHINES
- H02K17/00—Asynchronous induction motors; Asynchronous induction generators
- H02K17/02—Asynchronous induction motors
- H02K17/26—Asynchronous induction motors having rotors or stators designed to permit synchronous operation
-
- C—CHEMISTRY; METALLURGY
- C03—GLASS; MINERAL OR SLAG WOOL
- C03C—CHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
- C03C17/00—Surface treatment of glass, not in the form of fibres or filaments, by coating
- C03C17/22—Surface treatment of glass, not in the form of fibres or filaments, by coating with other inorganic material
-
- C—CHEMISTRY; METALLURGY
- C03—GLASS; MINERAL OR SLAG WOOL
- C03C—CHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
- C03C17/00—Surface treatment of glass, not in the form of fibres or filaments, by coating
- C03C17/02—Surface treatment of glass, not in the form of fibres or filaments, by coating with glass
- C03C17/04—Surface treatment of glass, not in the form of fibres or filaments, by coating with glass by fritting glass powder
-
- C—CHEMISTRY; METALLURGY
- C03—GLASS; MINERAL OR SLAG WOOL
- C03B—MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES
- C03B20/00—Processes specially adapted for the production of quartz or fused silica articles, not otherwise provided for
-
- C—CHEMISTRY; METALLURGY
- C03—GLASS; MINERAL OR SLAG WOOL
- C03C—CHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
- C03C3/00—Glass compositions
- C03C3/04—Glass compositions containing silica
- C03C3/06—Glass compositions containing silica with more than 90% silica by weight, e.g. quartz
-
- C—CHEMISTRY; METALLURGY
- C30—CRYSTAL GROWTH
- C30B—SINGLE-CRYSTAL GROWTH; UNIDIRECTIONAL SOLIDIFICATION OF EUTECTIC MATERIAL OR UNIDIRECTIONAL DEMIXING OF EUTECTOID MATERIAL; REFINING BY ZONE-MELTING OF MATERIAL; PRODUCTION OF A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; SINGLE CRYSTALS OR HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; AFTER-TREATMENT OF SINGLE CRYSTALS OR A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; APPARATUS THEREFOR
- C30B15/00—Single-crystal growth by pulling from a melt, e.g. Czochralski method
- C30B15/10—Crucibles or containers for supporting the melt
-
- H02K11/001—
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02K—DYNAMO-ELECTRIC MACHINES
- H02K11/00—Structural association of dynamo-electric machines with electric components or with devices for shielding, monitoring or protection
- H02K11/0094—Structural association with other electrical or electronic devices
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02K—DYNAMO-ELECTRIC MACHINES
- H02K11/00—Structural association of dynamo-electric machines with electric components or with devices for shielding, monitoring or protection
- H02K11/20—Structural association of dynamo-electric machines with electric components or with devices for shielding, monitoring or protection for measuring, monitoring, testing, protecting or switching
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02K—DYNAMO-ELECTRIC MACHINES
- H02K17/00—Asynchronous induction motors; Asynchronous induction generators
- H02K17/02—Asynchronous induction motors
- H02K17/22—Asynchronous induction motors having rotors with windings connected to slip-rings
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02K—DYNAMO-ELECTRIC MACHINES
- H02K3/00—Details of windings
- H02K3/04—Windings characterised by the conductor shape, form or construction, e.g. with bar conductors
- H02K3/28—Layout of windings or of connections between windings
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02K—DYNAMO-ELECTRIC MACHINES
- H02K5/00—Casings; Enclosures; Supports
- H02K5/04—Casings or enclosures characterised by the shape, form or construction thereof
- H02K5/22—Auxiliary parts of casings not covered by groups H02K5/06-H02K5/20, e.g. shaped to form connection boxes or terminal boxes
- H02K5/225—Terminal boxes or connection arrangements
-
- C—CHEMISTRY; METALLURGY
- C03—GLASS; MINERAL OR SLAG WOOL
- C03C—CHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
- C03C2217/00—Coatings on glass
- C03C2217/20—Materials for coating a single layer on glass
- C03C2217/21—Oxides
- C03C2217/213—SiO2
-
- C—CHEMISTRY; METALLURGY
- C03—GLASS; MINERAL OR SLAG WOOL
- C03C—CHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
- C03C2218/00—Methods for coating glass
- C03C2218/10—Deposition methods
- C03C2218/11—Deposition methods from solutions or suspensions
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10S428/00—Stock material or miscellaneous articles
- Y10S428/92—Fire or heat protection feature
- Y10S428/921—Fire or flameproofing
Definitions
- This invention relates to an electric machine or generator or motor and to a method to operate an electric machine or generator or motor or AC generator.
- an electric machine comprising a stator and a rotor, wherein the rotor is adapted to rotate relatively to the stator, and wherein the rotor comprises a rotor-switching device which is arranged at the rotor.
- the rotor-switching device comprises a rotor-control-unit and at least one switch which is adapted to electrically connect rotor-coils and/or to provide or disconnect an electric connection to a power source.
- the rotor-control-unit is adapted to activate preselected electrical switches at a predefined moment of time so that for a given rotor coil one of the following events occur:
- the switches are mechanical switches such as relays or semiconductor switches.
- the switches are adapted to electrically connect different rotor-coils.
- the switches are also adapted to provide a connection to the power supply.
- a number of switches is the same as the number of (rotor) coils.
- the switches are located in or at the rotor-switching-device, they also rotate together with the rotor-switching-device.
- the rotor comprises means to provide or conduct electric power, in particular a slip ring or a rotary transformer.
- a slip ring is an electrical connector designed to carry current or signals from a stationary wire into a rotating device. Typically, it consists of a stationary graphite or metal contact (brush) which rubs on the outside diameter of a rotating metal ring. As the metal ring turns, the electrical current or signal is conducted through the stationary brush to the metal ring making the connection. Additional ring/brush assemblies are stacked along the rotating axis if more than one electrical circuit is needed. Either the brushes or the rings are stationary and the other component rotates.
- a rotary (rotatory) transformer is a specialized transformer used to couple electrical signals between two parts that rotate in relation to each other.
- typical rotary transformers provide longer life than slip rings.
- the rotor comprises a plurality of slip rings or rotary transformers, dependent on the power supply or the current(s) and voltage(s) that have to be conducted.
- these means are arranged at a rotor axis of the rotor.
- the power source is an AC- or DC-power source.
- the rotor-switching device may comprise at least one electric inverter, such as a DC-DC-inverter, a DC-AC-inverter, an AC-AC-inverter and/or an AC-DC-inverter.
- a DC-DC-inverter such as a DC-DC-inverter, a DC-AC-inverter, an AC-AC-inverter and/or an AC-DC-inverter.
- AC-DC-inverter such as a DC-DC-inverter, a DC-AC-inverter, an AC-AC-inverter and/or an AC-DC-inverter.
- the stator comprises at least one stator-pole-pair, wherein the rotor comprises at least one rotor-pole-pair, wherein each pole-pair is formed by at least three coils.
- the rotor-switching-device is adapted to provide the rotor with DC and/or AC.
- the stator-switching-device is adapted to provide the stator with DC and/or AC.
- the electric machine can be operated in all its operation modes as generator and as motor. In one embodiment the electric machine can be operated as double fed machine. Double fed electric machines are such electric machines in which the rotor also takes active part in energy conversion process.
- the magnetic field created by the rotor is not static, but it is rotating relative to the rotor itself and electric energy is either “pumped” to the rotor or taken out of the rotor depending on current operation mode.
- the rotor may create a variable pole magnetic field which rotates relative to the rotor itself.
- the rotor as well as the stator can generate rotating magnetic fields (using e.g. three-phase AC).
- the stator-switching-device is adapted to vary a number of stator-pole-pairs by electrically connecting appropriate stator-coils, wherein the rotor-switching-device is adapted to vary a number of rotor-pole-pairs by electrically connecting appropriate rotor-coils.
- the electric machine can be a single fed synchronous machine.
- the stator-coils are provided with AC and the rotor-coils are provided with DC.
- the synchronous machine is an AC rotating machine whose speed under steady state condition is proportional to the frequency of the current in its armature, respectively, in its rotor. This is also named the “synchronous speed”.
- the synchronous speed N is given by
- Each pole pair comprises two poles, a north- and a south-pole.
- the smallest pole pair number is “1” (e. g. 1 north pole and 1 south pole).
- the number of stator-pole-pairs is the same as the number of rotor-pole-pairs. They correspond to each other. In other words, by varying the number of stator-pole-pairs, respectively, the number of rotor-pole-pairs, the number of magnetic poles and in consequence the synchronous speed N is changeable.
- the electric machine is adapted to change the pole number, respectively, the pole angular pitch while working (the pole pitch is defined as a peripheral distance between centres of two adjacent poles and the pole angular pitch is defined as the angle formed by the centres of two adjacent poles to the rotor's rotation axis).
- the electric machine can be operated at highest efficiency at different rotation speeds and a given power frequency.
- Another embodiment of the invention is capable to operate as double fed electric machine. In such case rotation speed N is a product of pole pair number and two frequencies—one supplied to the rotor and the other supplied to the stator.
- the electric machine in particular the rotor, can be operated with DC and/or AC, wherein AC comprises at least 3 phases.
- AC comprises at least 3 phases.
- a minimal number of phases is preferably 3 (phase A, phase B and phase C).
- polyphase systems with more phases are possible, e. g. 6 phases.
- the electric machine will operate as single fed induction machine. If the frequency of the multiphase AC source supplied to the rotor drops to zero then the electric machine will operate as single fed synchronous machine.
- Further benefits can bring the ability to connect sensors to the rotor-switching-device to monitor key characteristics of the rotor during operation. For instance temperature, rotor coil electric currents and other important readings can be monitored inside the rotor and information passed to the stator-switching-device via the information channel or the communication connection, respectively, between the two switching devices, This way malfunctions can be anticipated before a major accident occurs. It is also possible a set of gyroscopic sensors inside the rotor to determine exact position of the rotor at a certain moment of time. This may eliminate the need of complicated other sensors mounted outside the rotor with the same function.
- rotor-switching-device excites proper combination of rotor-coils to create rotor magnetic field with the same number of poles as the number of poles of momentary stator rotating magnetic field.
- a method to operate an electric machine comprising a stator and a rotor, wherein the rotor is adapted to rotate relatively to the stator, and wherein the rotor comprises a rotor-switching-device which is arranged at the rotor, comprises the steps:
- the method comprises also the steps:
- the method according to the invention can include the features and advantages of the electric machine according to the invention and vice versa.
- FIG. 1 shows a perspective view of an exemplary single fed embodiment of an electric machine
- FIG. 2 a shows a stator and rotor design of the electric machine of FIG. 1 ;
- FIG. 2 b shows a communication connection between a rotor-switching device and a stator-switching-device of the electric machine of FIG. 1
- the electric machine 20 comprises a stator 40 and a rotor 60 .
- a rotor-switching-device 64 is arranged at a rotor axis 61 of the rotor 60 .
- Means for providing or conducting electric power 62 such as slip rings or rotary transformers are also arranged at the rotation axis 61 . In this embodiment, they conduct current or voltages DC+V or DC ⁇ V, respectively, to the rotor-coils r of the rotor 60 .
- the electric machine 20 furthermore comprises a stator-switching-device 44 that is electrically connected to an AC power source or to phases A, B and C, respectively.
- the stator-coils s of the stator 40 are provided with alternating current.
- This type of electric machine is named single fed machine.
- FIGS. 2 a and 2 b show the design of the electric machine 20 more detailed.
- Switches l 19 , l 20 and l 21 are switched to position 1.
- Stator-coil s 10 is connected to phase A.
- Stator-coil s 11 is connected to phase B.
- Stator-coil s 12 is connected to phase C.
- Stator-coil s 13 is connected to phase A.
- Stator-coil s 14 is connected to phase B.
- Stator-coil s 9 is connected to phase C.
- Rotor switches l 15 , l 16 , l 17 and l 18 are switched to position 2.
- Switches l 19 , l 20 and l 21 are switched to position 2.
- Stator-coil s 10 is connected in reverse to phase A.
- Stator-coil s 11 is connected to phase B.
- Stator-coil s 12 is connected in reverse to phase C.
- Stator-coil s 13 is connected to phase A.
- Stator-coil s 14 is connected in reverse to phase B.
- Stator-coil s 9 is connected to phase. This forms a familiar two pole stator-coil configuration—A B- C A- B C-.
- Rotor switches l 15 , l 16 , l 17 and l 18 are switched to position 3. This way the rotor-coils r 6 and r 8 will create a 2 pole magnetic field SN.
- Rotor-coils r 5 and r 7 are connected in short to work in induction mode to assist the rotor to reach synchronous speed. When rotor speed is synchronized with stator rotating 2 pole field the rotor will follow synchronously the stator rotating field.
- Switches l 19 , l 20 and l 21 are switched to position 1.
- Stator-coil s 10 is connected to phase A.
- Stator-coil s 11 is connected to phase B.
- Stator-coil s 12 is connected to phase C.
- Stator-coil s 13 is connected to phase A.
- Stator-coil s 14 is connected to phase B.
- Stator-coil s 9 is connected to phase C.
- Rotor switches l 15 , l 16 , l 17 and l 18 are switched to position 4. This way the rotor-coils r 5 , r 6 , r 7 and r 8 are connected in short. Stator rotating field will induce currents in rotor-coils making the rotor follow stator field at sub synchronous speed.
- Switches l 19 , l 20 and l 21 are switched to position 2.
- Stator-coil s 10 is connected in reverse to phase A.
- Stator-coil s 11 is connected to phase B.
- Stator-coil s 12 is connected in reverse to phase C.
- Stator-coil s 13 is connected to phase A.
- Stator-coil s 14 is connected in reverse to phase B.
- Stator-coil s 9 is connected to phase C.
- Rotor switches l 15 , l 16 , l 17 and l 18 are switched to position 4. This way the rotor-coils r 5 , r 6 , r 7 and r 8 are connected in short. Stator rotating field will induce currents in rotor-coils making the rotor follow stator field at sub synchronous speed.
- Rotor switches l 15 , l 16 , l 17 and l 18 are switched to position 1. All rotor-coils are open. The rotor will not produce any torque, regardless of presence of stator field and rotor power supply.
- single fed machine there may be a DC to DC inverter as part of the rotor switching device. This way high voltage DC can be supplied to slip rings and the built in rotor switching device DC to DC inverter to reduce the voltage to appropriate level. This way current over slip rings will be reduced bringing down losses and wear of the slip rings.
- the brushes and slip rings can be replaced by a rotating transformer, having its primary coil stationary and its secondary coil mounted on the rotor and rotating along with it. This way AC will be supplied and integrated in rotor switching device AC to DC inverter should provide transition from AC to DC current needed to excite rotor-coils to produce magnetic field, static relative to the rotor. In this case brushes and slip rings are eliminated altogether.
- FIG. 3 basically shows the same concept as FIG. 1 .
- a rotor 60 is provided with alternating current.
- This type of machine is named doubly fed machine.
- FIG. 4 b shows the design in detail.
- FIG. 4 a shows basically the same design as FIG. 2 b .
- a rotor-switching-device 64 is provided with alternating current C′, B′, A′.
- Switches l 15 , l 16 , l 17 , l 18 , l 34 and l 35 are operated by a rotor-control-unit 66 so that their switch position is the same and changed simultaneously from 1 to 4.
- Switches l 19 , l 20 and l 21 are operated by a stator-control-unit 46 so that their switch position is the same and changed simultaneously from 1 to 2. All switches depicted on FIG. 4 a are shown in position 1.
- Rotor-coil r 5 is connected to phase A′
- rotor-coil r 6 is connected to phase C′
- rotor-coil r 7 is connected to phase B′
- rotor-coil r 8 is connected to phase A′
- rotor-coil r 32 is connected to phase C′
- rotor-coil r 33 is connected to phase B′.
- Switches l 19 , l 20 and l 21 are switched to position 2.
- Stator-coil s 10 is connected in reverse to phase A.
- Stator-coil s 12 is connected in reverse to phase C.
- Stator-coil s 13 is connected to phase A.
- Stator-coil r 14 is connected in reverse to phase B.
- Stator-coil s 9 is connected to phase C. This forms a familiar two pole stator-coil configuration—A B- C A- B C-.
- Rotor switches l 15 , l 16 , l 17 , l 18 , l 34 and l 35 are switched to position 3.
- Rotor-coil r 5 is connected to phase A′
- rotor-coil r 6 is connected in reverse to phase C′
- rotor-coil r 7 is connected to phase B′
- rotor-coil r 8 is connected in reverse to phase A′
- rotor-coil r 32 is connected to phase C′
- rotor-coil r 33 is connected in reverse to phase B′.
- Switches l 19 , l 20 and l 21 are switched to position 1.
- Stator-coil s 10 is connected to phase A.
- Stator-coil s 11 is connected to phase B.
- Stator-coil s 12 is connected to phase C.
- Stator-coil s 13 is connected to phase A.
- Stator-coil s 14 is connected to phase B.
- Stator-coil s 9 is connected to phase C.
- Rotor switches l 15 , l 16 , l 17 , l 18 , l 34 and l 35 are switched to position 4.
- Stator rotating field will induce currents in rotor-coils making the rotor follow stator field at sub synchronous speed.
- Two pole induction mode operation Switches l 19 , l 20 and l 21 are switched to position 2.
- Stator-coil s 10 is connected in reverse to phase A.
- Stator-coil s 11 is connected to phase B.
- Stator-coil s 12 is connected in reverse to phase C.
- Stator-coil s 13 is connected to phase A.
- Stator-coil s 14 is connected in reverse to phase B.
- Stator-coil s 9 is connected to phase C.
Landscapes
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Materials Engineering (AREA)
- Organic Chemistry (AREA)
- Power Engineering (AREA)
- Life Sciences & Earth Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- General Chemical & Material Sciences (AREA)
- Geochemistry & Mineralogy (AREA)
- Microelectronics & Electronic Packaging (AREA)
- Metallurgy (AREA)
- Crystallography & Structural Chemistry (AREA)
- Glass Melting And Manufacturing (AREA)
- Silicon Compounds (AREA)
- Application Of Or Painting With Fluid Materials (AREA)
- Crystals, And After-Treatments Of Crystals (AREA)
- Compositions Of Oxide Ceramics (AREA)
- Synchronous Machinery (AREA)
Abstract
An electric machine that includes a stator and a rotor, wherein the rotor is adapted to rotate relatively to the stator, and wherein the rotor comprises a rotor-switching-device which is arranged at the rotor.
Description
- This invention relates to an electric machine or generator or motor and to a method to operate an electric machine or generator or motor or AC generator.
- In the prior art different types of electric machines (motors and generators) with wound or cage rotors are known. Such electric machines are divided into two major groups: synchronous machines and induction machines. Induction machines are quite flexible in terms of rotation speed and torque. In this context it is also known to vary the stator pole pitch and thus to further increase the flexibility of such induction machines. However, the main disadvantage of induction machines is the relatively low efficiency compared to synchronous electric machines. Although synchronous machines are more efficient, the efficiency is limited to only one rotation speed: the synchronous speed of the rotor with the AC frequency supplied to the machine. Thus, synchronous machines are not flexible enough.
- Therefore, it is an object of the current invention to provide an electric machine and methods to operate an electric machine with high efficiency at different rotation speeds.
- According to the invention, there is provided an electric machine, comprising a stator and a rotor, wherein the rotor is adapted to rotate relatively to the stator, and wherein the rotor comprises a rotor-switching device which is arranged at the rotor.
- Expediently, the rotor-switching device comprises a rotor-control-unit and at least one switch which is adapted to electrically connect rotor-coils and/or to provide or disconnect an electric connection to a power source. In particular, the rotor-control-unit is adapted to activate preselected electrical switches at a predefined moment of time so that for a given rotor coil one of the following events occur:
-
- Electrically connect the rotor coil(s) to a DC power source so that polarity is also selectable;
- Electrically connect the rotor coil(s) to a selected phase of a multiphase AC power source so that polarity is also selectable;
- Short-circuit the rotor coil(s);
- Connect the rotor coil(s) to an electrical load;
- Leave the rotor coil(s) electrically disconnected.
- In a preferred embodiment, the switches are mechanical switches such as relays or semiconductor switches. As already mentioned, the switches are adapted to electrically connect different rotor-coils. However, the switches are also adapted to provide a connection to the power supply. In one embodiment, a number of switches is the same as the number of (rotor) coils. Preferably, as the switches are located in or at the rotor-switching-device, they also rotate together with the rotor-switching-device.
- In one embodiment, the rotor comprises means to provide or conduct electric power, in particular a slip ring or a rotary transformer. A slip ring is an electrical connector designed to carry current or signals from a stationary wire into a rotating device. Typically, it consists of a stationary graphite or metal contact (brush) which rubs on the outside diameter of a rotating metal ring. As the metal ring turns, the electrical current or signal is conducted through the stationary brush to the metal ring making the connection. Additional ring/brush assemblies are stacked along the rotating axis if more than one electrical circuit is needed. Either the brushes or the rings are stationary and the other component rotates. A rotary (rotatory) transformer is a specialized transformer used to couple electrical signals between two parts that rotate in relation to each other. Preferably, typical rotary transformers provide longer life than slip rings. Expediently, the rotor comprises a plurality of slip rings or rotary transformers, dependent on the power supply or the current(s) and voltage(s) that have to be conducted. Preferably, these means are arranged at a rotor axis of the rotor. Preferably, the power source is an AC- or DC-power source.
- Expediently, the rotor-switching device may comprise at least one electric inverter, such as a DC-DC-inverter, a DC-AC-inverter, an AC-AC-inverter and/or an AC-DC-inverter. The same applies to the stator-switching-device.
- In a preferred embodiment, the electric machine comprises a stator-switching-device which comprises a stator-control-unit, wherein the stator-switching-device comprises at least one switch which is adapted to electrically connect stator-coils and/or to provide or disconnect an electric connection to the power source. Preferably, these switches are of the same type and design as the switches of the rotor-switching-device. Thus, the same features and advantages apply. In particular, the stator-switching-device is adapted to activate preselected electrical switches at a predefined moment of time so that for a given stator coil one of the following events occur:
-
- Electrically connect the stator coil(s) to a selected phase of a multiphase AC power source so that polarity is also selectable;
- Electrically connect the stator coil(s) to a DC power source so that polarity is also selectable;
- Short-circuit the stator coil(s);
- Connect the stator coil(s) to an electrical load;
- Leave the stator coil(s) electrically disconnected.
- Expediently, the stator comprises at least one stator-pole-pair, wherein the rotor comprises at least one rotor-pole-pair, wherein each pole-pair is formed by at least three coils. The rotor-switching-device is adapted to provide the rotor with DC and/or AC. In the same manner, the stator-switching-device is adapted to provide the stator with DC and/or AC. Generally, the electric machine can be operated in all its operation modes as generator and as motor. In one embodiment the electric machine can be operated as double fed machine. Double fed electric machines are such electric machines in which the rotor also takes active part in energy conversion process. The magnetic field created by the rotor is not static, but it is rotating relative to the rotor itself and electric energy is either “pumped” to the rotor or taken out of the rotor depending on current operation mode. In the present invention the rotor may create a variable pole magnetic field which rotates relative to the rotor itself. The rotor as well as the stator can generate rotating magnetic fields (using e.g. three-phase AC). Preferably, the stator-switching-device is adapted to vary a number of stator-pole-pairs by electrically connecting appropriate stator-coils, wherein the rotor-switching-device is adapted to vary a number of rotor-pole-pairs by electrically connecting appropriate rotor-coils. In one embodiment, the electric machine can be a single fed synchronous machine. In this case, the stator-coils are provided with AC and the rotor-coils are provided with DC. The synchronous machine is an AC rotating machine whose speed under steady state condition is proportional to the frequency of the current in its armature, respectively, in its rotor. This is also named the “synchronous speed”. The synchronous speed N is given by
-
N=f/p·60 s/min - where,
f is the frequency of the AC supply current (power frequency) in Hz, and p is the is the number of pole pairs. - Each pole pair comprises two poles, a north- and a south-pole. Thus, the smallest pole pair number is “1” (e. g. 1 north pole and 1 south pole). Preferably, the number of stator-pole-pairs is the same as the number of rotor-pole-pairs. They correspond to each other. In other words, by varying the number of stator-pole-pairs, respectively, the number of rotor-pole-pairs, the number of magnetic poles and in consequence the synchronous speed N is changeable. Advantageously, the electric machine is adapted to change the pole number, respectively, the pole angular pitch while working (the pole pitch is defined as a peripheral distance between centres of two adjacent poles and the pole angular pitch is defined as the angle formed by the centres of two adjacent poles to the rotor's rotation axis). Thus, the electric machine can be operated at highest efficiency at different rotation speeds and a given power frequency. Another embodiment of the invention is capable to operate as double fed electric machine. In such case rotation speed N is a product of pole pair number and two frequencies—one supplied to the rotor and the other supplied to the stator. By varying pole pair numbers of the rotor and the stator the present invention increases functionality of a double fed machine too, as there will be at least two different synchronous rotation speeds for every two given supply frequencies. The electric machine can be operated as AC motor and as AC generator at a variety of output frequencies at a given rotation speed. The rotor is adapted to create a variable magnetic field which can vary on command in terms of direction and magnitude, relative to the rotor itself. The rotor comprises a rotor or rotation axis, respectively, and is supported inside the stator. Both, the stator and the rotor, extend along the rotation axis. The stator of the electric machine consists preferably of a laminated electrical steel core that comprises the stator-coils. The stator-switching-device preferably connects the stator-coils with a polyphase system. Polyphase systems have three or more energized electrical conductors carrying alternating currents with a definite time offset between the voltage waves in each conductor. With polyphase power a rotating magnetic field can be generated. Preferably, three coils are connected to form a three-phase winding, respectively, system. Advantageously, this connection is not fixed. The connection is provided by the stator-switching-device and so different coils and also a different number of coils can be connected to each and every AC phase to vary the number of poles, respectively, pole pairs of the stator and in consequence, the synchronous rotation speed of the electric machine. The same is valid for the rotor-switching-device and the rotor-coils. To further improve rotor rotation speed flexibility, the rotor-coils are preferably provided with AC by the rotor-switching-device, thus operating the electric machine as double fed machine. This means that both, the stator and the rotor, generate a rotating magnetic field using AC current. In one embodiment, the rotating magnetic fields of the stator and the rotor rotate in different directions.
- Preferably, the stator comprises a plurality of stator-slots and the rotor comprises a plurality of rotor-slots, wherein each stator-coil is arranged in at least two stator-slots, and wherein each rotor-coil is arranged in at least two rotor-slots. Preferably, the rotor-coils as well as the stator-coils extend substantially parallel to the rotation axis. However, it is also possible that the rotor-coils and/or the stator-coils extend at least partly transverse or oblique to the rotation axis. In addition, the rotor-coils and/or the stator-coils can have at least partly a corrugated form along the rotation axis.
- In a single fed electric machine embodiment there are preferably four rotor slots and six stator slots. The number of rotor coils is preferably four and the number of stator coils is preferably six. Each coil occupies two adjacent slots, thus a stator coil annular pitch is 60° and a rotor coil angular pitch is 90°. The rotor is expediently supplied with DC through two slip rings.
- In a double fed electric machine embodiment there are preferably six rotors slots and preferably six stator slots. The number of rotor coils is preferably six and the number of stator coils is preferably six. Each coil occupies two adjacent slots, thus a stator coil angular pitch is 60° and a rotor coil angular pitch is 60. The rotor is expediently supplied with AC through slip rings.
- It shall be understood that embodiments with different number of coils and slots, e. g. 18, 24 or 48 etc. are also possible and preferred.
- Expediently, the electric machine, in particular the rotor, can be operated with DC and/or AC, wherein AC comprises at least 3 phases. In other words, a minimal number of phases is preferably 3 (phase A, phase B and phase C). It goes without saying that also polyphase systems with more phases are possible, e. g. 6 phases.
- Advantageously, the electric machine can be operated as synchronous machine and as induction machine. In induction operation mode the rotor switching device switches rotor-coils in short and not to any of the AC phases or the DC power source. The rotating magnetic field created by the stator will induce electric currents in the rotor-coils which is the principle behind induction motors. By selecting a combination of coils and polarities to excite the rotor, the rotor-switching-device is capable of changing the magnetic pole number of the rotor. It is adapted to connect rotor-coils in short thus operating the electric machine in induction mode. This is useful when starting the electric machine and also during transition between two synchronous speeds. Electric power is delivered to the rotor via e. g. two slip rings or brushless via rotary transformers and rectifiers.
- The rotor may be also connected to a multiphase AC source to operate as double fed machine to create a rotor rotating magnetic field. Multiphase AC is brought to the rotor switching device via slip rings (at least 3) or via a set of rotating transformers. By selecting a combination of coils and polarities to be connected to a certain phase, the magnetic pole number of the rotating magnetic field can be beneficially changed. A communication connection between the rotor switching device and the stator switching device or its control units, respectively, is used to coordinate both devices so that the pole pair number and the rotating magnetic field of the rotor and the pole pair number and the rotating magnetic field of the stator are for example the same. In particular, if the rotor-coils are connected in short by the rotor switching device, the electric machine will operate as single fed induction machine. If the frequency of the multiphase AC source supplied to the rotor drops to zero then the electric machine will operate as single fed synchronous machine. Further benefits can bring the ability to connect sensors to the rotor-switching-device to monitor key characteristics of the rotor during operation. For instance temperature, rotor coil electric currents and other important readings can be monitored inside the rotor and information passed to the stator-switching-device via the information channel or the communication connection, respectively, between the two switching devices, This way malfunctions can be anticipated before a major accident occurs. It is also possible a set of gyroscopic sensors inside the rotor to determine exact position of the rotor at a certain moment of time. This may eliminate the need of complicated other sensors mounted outside the rotor with the same function.
- In both cases (rotor supplied with AC or DC), the stator may be designed or operated similarly. The stator-switching-device electrically connects the stator-coils to a multiphase AC source to create a rotating magnetic field. By selecting a combination of coils and polarities to be connected to a certain phase, the magnetic pole number of the rotating magnetic field can be beneficially changed. A communication connection between the stator switching device and the rotor switching device or its control units, respectively, is used to coordinate both devices so that rotor pole numbers and stator pole pair numbers are the same. If rotor speed is very different from synchronous speed then induction mode is activated (rotor switching device connects rotor-coils in short). When the rotor reaches speed close to synchronous speed then rotor-switching-device excites proper combination of rotor-coils to create rotor magnetic field with the same number of poles as the number of poles of momentary stator rotating magnetic field.
- Another advantage presents the energy storage device inside the rotor. It can be a battery, capacitor or other device which stores electric energy. It can be used to supply power to the rotor switching device in case of power breakdown to the rotor. Using the supply from the energy storage device, the rotor switching device can perform a controlled emergency stop procedure in coordination with the stator switching device.
- According to the invention, a method to operate an electric machine, comprising a stator and a rotor, wherein the rotor is adapted to rotate relatively to the stator, and wherein the rotor comprises a rotor-switching-device which is arranged at the rotor, comprises the steps:
-
- providing the stator with AC using a stator-switching device;
- providing the rotor with AC or DC or short-circuiting the rotor using the rotor-switching-device.
- Advantageously, the method comprises also the steps:
-
- selecting a (proper) stator pole pair number using the stator-switching device; selecting (proper) corresponding operational mode for the rotor using the rotor-switching-device such as induction, synchronous or double fed.
- The method according to the invention can include the features and advantages of the electric machine according to the invention and vice versa.
- Additional advantages and features of the current invention are shown in the following description of preferred embodiments of the current invention with reference to the attached drawings. Single features or characteristics of respective embodiments are explicitly allowed to be combined within the scope of the current invention.
-
FIG. 1 : shows a perspective view of an exemplary single fed embodiment of an electric machine; -
FIG. 2 a: shows a stator and rotor design of the electric machine ofFIG. 1 ; -
FIG. 2 b: shows a communication connection between a rotor-switching device and a stator-switching-device of the electric machine ofFIG. 1 -
FIG. 3 : shows a perspective view of a double fed embodiment of an electric machine; -
FIG. 4 a: shows a stator and rotor design of the electric machine ofFIG. 3 ; -
FIG. 4 b: shows a communication connection between a rotor-switching-device and a stator-switching-device of the electric machine ofFIG. 3 . - Referring now to
FIG. 1 , a perspective view of anelectric machine 20 is shown. Theelectric machine 20 comprises astator 40 and arotor 60. A rotor-switching-device 64 is arranged at arotor axis 61 of therotor 60. Means for providing or conductingelectric power 62 such as slip rings or rotary transformers are also arranged at therotation axis 61. In this embodiment, they conduct current or voltages DC+V or DC−V, respectively, to the rotor-coils r of therotor 60. Theelectric machine 20 furthermore comprises a stator-switching-device 44 that is electrically connected to an AC power source or to phases A, B and C, respectively. Thus, the stator-coils s of thestator 40 are provided with alternating current. This type of electric machine is named single fed machine.FIGS. 2 a and 2 b show the design of theelectric machine 20 more detailed. -
FIG. 2 a shows acommunication connection 50 between the rotor-switching-device 64 and the stator-switchingdevice 44. In particular, a rotor-control-unit 66 is connected to a stator-control-unit 46. The rotor-switching-device 64 also comprises asensor 92 and a rotorenergy storage unit 90. -
FIG. 2 b: Switches l15, l16, l17 and l18 (FIG. 2 b) are operated by a rotor-control-unit 66 so that their switch position is the same and changed simultaneously from 1 to 4. Switches l19, l20 and l21 are operated by the stator-control-unit 46 so that their switch position is the same and changed simultaneously from 1 to 2. All switches depicted onFIG. 2 a are shown in position 1. Below, different operation modes are described: - Four pole synchronous mode operation: Switches l19, l20 and l21 are switched to position 1. Stator-coil s10 is connected to phase A. Stator-coil s11 is connected to phase B. Stator-coil s12 is connected to phase C. Stator-coil s13 is connected to phase A. Stator-coil s14 is connected to phase B. Stator-coil s9 is connected to phase C. This forms a familiar four pole stator-coil configuration—ABCABC. Rotor switches l15, l16, l17 and l18 are switched to position 2. This way the rotor-coils r5, r6, r7 and r8 will create a 4 pole magnetic field SNSN (south-north-south-north). When rotor speed is synchronized with stator rotating 4 pole field the rotor will follow synchronously the stator rotating field.
- Two pole synchronous mode operation: Switches l19, l20 and l21 are switched to position 2. Stator-coil s10 is connected in reverse to phase A. Stator-coil s11 is connected to phase B. Stator-coil s12 is connected in reverse to phase C. Stator-coil s13 is connected to phase A. Stator-coil s14 is connected in reverse to phase B. Stator-coil s9 is connected to phase. This forms a familiar two pole stator-coil configuration—A B- C A- B C-. Rotor switches l15, l16, l17 and l18 are switched to position 3. This way the rotor-coils r6 and r8 will create a 2 pole magnetic field SN. Rotor-coils r5 and r7 are connected in short to work in induction mode to assist the rotor to reach synchronous speed. When rotor speed is synchronized with stator rotating 2 pole field the rotor will follow synchronously the stator rotating field.
- Four pole induction mode operation: Switches l19, l20 and l21 are switched to position 1. Stator-coil s10 is connected to phase A. Stator-coil s11 is connected to phase B. Stator-coil s12 is connected to phase C. Stator-coil s13 is connected to phase A. Stator-coil s14 is connected to phase B. Stator-coil s9 is connected to phase C. This forms a familiar four pole stator-coil configuration—ABCABC. Rotor switches l15, l16, l17 and l18 are switched to position 4. This way the rotor-coils r5, r6, r7 and r8 are connected in short. Stator rotating field will induce currents in rotor-coils making the rotor follow stator field at sub synchronous speed.
- Two pole induction mode operation: Switches l19, l20 and l21 are switched to position 2. Stator-coil s10 is connected in reverse to phase A. Stator-coil s11 is connected to phase B. Stator-coil s12 is connected in reverse to phase C. Stator-coil s13 is connected to phase A. Stator-coil s14 is connected in reverse to phase B. Stator-coil s9 is connected to phase C. This forms a familiar two pole stator-coil configuration—A B- C A- B C-. Rotor switches l15, l16, l17 and l18 are switched to position 4. This way the rotor-coils r5, r6, r7 and r8 are connected in short. Stator rotating field will induce currents in rotor-coils making the rotor follow stator field at sub synchronous speed.
- Emergency stop: Rotor switches l15, l16, l17 and l18 are switched to position 1. All rotor-coils are open. The rotor will not produce any torque, regardless of presence of stator field and rotor power supply. In another embodiment single fed machine there may be a DC to DC inverter as part of the rotor switching device. This way high voltage DC can be supplied to slip rings and the built in rotor switching device DC to DC inverter to reduce the voltage to appropriate level. This way current over slip rings will be reduced bringing down losses and wear of the slip rings. Furthermore in another embodiment the brushes and slip rings can be replaced by a rotating transformer, having its primary coil stationary and its secondary coil mounted on the rotor and rotating along with it. This way AC will be supplied and integrated in rotor switching device AC to DC inverter should provide transition from AC to DC current needed to excite rotor-coils to produce magnetic field, static relative to the rotor. In this case brushes and slip rings are eliminated altogether.
-
FIG. 3 basically shows the same concept asFIG. 1 . However, arotor 60 is provided with alternating current. This type of machine is named doubly fed machine.FIG. 4 b shows the design in detail. -
FIG. 4 a shows basically the same design asFIG. 2 b. However, according to the design of the electric machine ofFIG. 3 , a rotor-switching-device 64 is provided with alternating current C′, B′, A′. - Switches l15, l16, l17, l18, l34 and l35 (
FIG. 4 b) are operated by a rotor-control-unit 66 so that their switch position is the same and changed simultaneously from 1 to 4. Switches l19, l20 and l21 are operated by a stator-control-unit 46 so that their switch position is the same and changed simultaneously from 1 to 2. All switches depicted onFIG. 4 a are shown in position 1. - Below, different operation modes are described:
- Four pole doubly fed mode operation: Switches l19, l20 and l21 are switched to position 1. Stator-coil s10 is connected to phase A. Stator-coil s11 is connected to phase B. Stator-coil s12 is connected to phase C. Stator-coil s13 is connected to phase A. Stator-coil s14 is connected to phase B. Stator-coil s9 is connected to phase C. This forms a familiar four pole stator-coil configuration—ABCABC. Rotor switches l15, l16, l17, l18, l34 and l35 are switched to position 2. Rotor-coil r5 is connected to phase A′, rotor-coil r6 is connected to phase C′, rotor-coil r7 is connected to phase B′, rotor-coil r8 is connected to phase A′, rotor-coil r32 is connected to phase C′, rotor-coil r33 is connected to phase B′. These connections form a four pole rotating field—A′C′B′A′C′B′. This field rotates relative to the rotor and its direction is opposite to the stator rotating field. This way the rotor will accelerate to an angular speed which the sum of the angular speeds of both stator and rotor rotating fields.
- Two pole doubly fed mode operation: Switches l19, l20 and l21 are switched to position 2. Stator-coil s10 is connected in reverse to phase A. Stator-coil s12 is connected in reverse to phase C. Stator-coil s13 is connected to phase A. Stator-coil r14 is connected in reverse to phase B. Stator-coil s9 is connected to phase C. This forms a familiar two pole stator-coil configuration—A B- C A- B C-. Rotor switches l15, l16, l17, l18, l34 and l35 are switched to position 3. Rotor-coil r5 is connected to phase A′, rotor-coil r6 is connected in reverse to phase C′, rotor-coil r7 is connected to phase B′, rotor-coil r8 is connected in reverse to phase A′, rotor-coil r32 is connected to phase C′, rotor-coil r33 is connected in reverse to phase B′. These connections form a two pole rotating field—A′ C′- B′ A′- C′ B′-. This field rotates relative to the rotor and its direction is opposite to the stator rotating field. This way the rotor will accelerate to an angular speed which the sum of the angular speeds of both stator and rotor rotating fields.
- Four pole induction mode operation: Switches l19, l20 and l21 are switched to position 1. Stator-coil s10 is connected to phase A. Stator-coil s11 is connected to phase B. Stator-coil s12 is connected to phase C. Stator-coil s13 is connected to phase A. Stator-coil s14 is connected to phase B. Stator-coil s9 is connected to phase C. This forms a familiar four pole stator-coil configuration—ABCABC. Rotor switches l15, l16, l17, l18, l34 and l35 are switched to position 4. This way the rotor-coils r5, r6, r7, r8, r32 and r33 are connected in short. Stator rotating field will induce currents in rotor-coils making the rotor follow stator field at sub synchronous speed. Two pole induction mode operation: Switches l19, l20 and l21 are switched to position 2. Stator-coil s10 is connected in reverse to phase A. Stator-coil s11 is connected to phase B. Stator-coil s12 is connected in reverse to phase C. Stator-coil s13 is connected to phase A. Stator-coil s14 is connected in reverse to phase B. Stator-coil s9 is connected to phase C. This forms a familiar two pole stator-coil configuration—A B - C A - B C. Rotor switches l15, l16, l17, l18, l34 and l35 are switched to position 4. This way the rotor-coils r5, r6, r7, r8, r32 and r33 are connected in short. Stator rotating field will induce currents in rotor-coils making the rotor follow stator field at sub synchronous speed.
- Emergency stop: Rotor switches l15, l16, l17, l18, l34 and l35 are switched to position 1. All rotor-coils r5, r6, r7, r8, r32 and r33 are open. The rotor will not produce any torque as no current would pass through rotor-coils, regardless of presence of stator field and rotor AC power supply. In another embodiment of doubly fed machine there may be a DC to AC inverter as part of the rotor switching device. This way high voltage DC can be supplied to slip rings and the built in DC to AC inverter to supply rotor-coils with multiphase AC to produce rotating magnetic field. Furthermore in another embodiment the brushes and slip rings can be replaced by a rotating transformer, having its primary coil stationary and its secondary coil mounted on the rotor and rotating along with it. This way AC will be supplied and internal AC to AC inverter should provide transition from AC to AC current again to supply rotor-coils with multiphase AC to produce rotating magnetic field by the rotor-coils. In this case brushes and slip rings are eliminated altogether. In both cases of DC to AC inverter with slip rings or AC to AC inverter being used the inverter should be reversible so that when the rotor is spinning at sub synchronous speed electric energy induced in rotor-coils should be transported out of the rotor through the slip rings or rotating transformer.
-
- 20 electric machine
- 40 stator
- 44 stator-switching-device
- 46 stator-control-unit
- 50 communication connection
- 60 rotor
- 61 rotor axis
- 62 means to conduct/provide electric power
- 66 rotor-control-unit
- 64 rotor-switching device
- 90 rotor energy storage unit
- 92 set of sensors
- AC alternating current
- DC, DC +V, DC −V direct current
- A, B, C . . . phases (stator)
- A′, B′, C′ . . . phases (rotor)
- V1, V2, V3 . . . voltages
- R rotation axis
- s, s1, s2, s3 . . . stator-coils
- r, r1, r2, r3 . . . rotor-coils
- l, l1, l2, l3, . . . switches
Claims (24)
1-11. (canceled)
12. An electric machine, comprising:
a stator; and
a rotor that is configured to rotate relative to the stator, wherein the rotor comprises a rotor-switching-device that is arranged at the rotor.
13. The electric machine according to claim 12 , wherein the rotor-switching-device comprises at least one switch that is configured to at least one of electrically connect a plurality of rotor-coils and disconnect an electric connection to a power source.
14. The electric machine according to claim 13 , wherein the rotor-switching-device comprises at least one switch that is configured to at least one of electrically connect a plurality of rotor-coils and disconnect an electric connection to a power source.
15. The electric machine according to claim 13 , wherein the rotor comprises an apparatus to at least one of provide and conduct electric.
16. The electric machine according to claim 15 , wherein the apparatus comprises at least one of a slip ring and a rotary transformer.
17. The electric machine according to claim 15 , wherein the rotor-switching-device comprises at least one electric inverter.
18. The electric machine of claim 17 , wherein the at least one electric inverter comprises at least one of a DC-DC-inverter, a DC-AC-inverter, an AC-AC-inverter, and an AC-DC-inverter.
19. The electric machine according to claim 17 , further comprising:
a stator-switching-device that comprises at least one switch that is configured to at least one of electrically connect a plurality of stator-coils, and provide an electric connection to a power source.
20. The electric machine according to claim 19 , wherein the stator-switching-device is adapted to vary a number of stator-pole-pairs, and wherein the rotor-switching-device is adapted to vary a number of rotor-pole-pairs.
21. The electric machine according to claim 20 , wherein the rotor-switching-device and the stator-switching-device are connected by a communication connection.
22. The electric machine according to claim 21 , wherein the power source comprises at least one of an AC-power source and a DC-power source.
23. The electric machine according to claim 22 , wherein the rotor comprises at least one sensor that is configured to provide information about a status of the rotor, including at least one of rotor position, rotor internal temperature, electric currents in rotor coils, power supply conditions, and vibration levels.
24. The electric machine according to claim 23 , wherein the rotor-switching-device comprises a rotor energy-storage-unit.
25. The electric machine according to claim 12 , wherein the rotor comprises an apparatus to at least one of provide and conduct electric.
26. The electric machine according to claim 25 , wherein the apparatus comprises at least one of a slip ring and a rotary transformer.
27. The electric machine according to claim 12 , wherein the rotor-switching-device comprises at least one electric inverter.
28. The electric machine of claim 27 , wherein the at least one electric inverter comprises at least one of a DC-DC-inverter, a DC-AC-inverter, an AC-AC-inverter, and an AC-DC-inverter.
29. The electric machine according to claim 12 , further comprising:
a stator-switching-device that comprises at least one switch that is configured to at least one of electrically connect a plurality of stator-coils, and provide an electric connection to a power source.
30. The electric machine according to claim 12 , wherein the stator-switching-device is adapted to vary a number of stator-pole-pairs, and wherein the rotor-switching-device is adapted to vary a number of rotor-pole-pairs.
31. The electric machine according to claim 30 , wherein the rotor-switching-device and the stator-switching-device are connected by a communication connection.
32. The electric machine according to claim 12 , wherein the rotor comprises at least one sensor that is configured to provide information about a status of the rotor, including at least one of rotor position, rotor internal temperature, electric currents in rotor coils, power supply conditions, and vibration levels.
33. The electric machine according to claim 12 , wherein the rotor-switching-device comprises a rotor energy-storage-unit.
34. A method to operate an electric machine, comprising the steps of:
providing a stator; and
providing a rotor configured to rotate relative to the stator, wherein the rotor comprises a rotor-switching-device that is arranged at the rotor;
providing the stator with AC using a stator-switching device; and
at least one of providing the rotor with AC and DC, and short-circuiting the rotor using the rotor-switching-device.
Applications Claiming Priority (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
EP13194963.8A EP2878584B1 (en) | 2013-11-28 | 2013-11-28 | Method for producing a coated component of quartz glass or fused silica |
EP13194963.4 | 2013-11-28 | ||
PCT/EP2014/069035 WO2015078603A1 (en) | 2013-11-28 | 2014-09-08 | Electric machine |
Publications (1)
Publication Number | Publication Date |
---|---|
US20150364978A1 true US20150364978A1 (en) | 2015-12-17 |
Family
ID=49679395
Family Applications (2)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US14/391,970 Abandoned US20150364978A1 (en) | 2013-11-28 | 2014-09-08 | Electric Machine |
US14/543,718 Active US9680360B2 (en) | 2013-11-28 | 2014-11-17 | Method for producing a coated component of transparent or opaque fused silica |
Family Applications After (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US14/543,718 Active US9680360B2 (en) | 2013-11-28 | 2014-11-17 | Method for producing a coated component of transparent or opaque fused silica |
Country Status (5)
Country | Link |
---|---|
US (2) | US20150364978A1 (en) |
EP (1) | EP2878584B1 (en) |
JP (1) | JP5940134B2 (en) |
KR (1) | KR101649523B1 (en) |
CN (1) | CN104671670B (en) |
Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20180375414A1 (en) * | 2015-10-15 | 2018-12-27 | Vastech Holdings Ltd. | Electric motor |
US20200106318A1 (en) * | 2016-10-28 | 2020-04-02 | Waymo Llc | Devices and Methods for Driving a Rotary Platform |
US10916999B2 (en) | 2013-03-19 | 2021-02-09 | Intellitech Pty Ltd | Device and method for using a magnetic clutch in BLDC motors |
US11462983B2 (en) | 2017-12-28 | 2022-10-04 | Intellitech Pty Ltd | Electric motor |
US11909263B1 (en) | 2016-10-19 | 2024-02-20 | Waymo Llc | Planar rotary transformer |
Families Citing this family (10)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
KR102397734B1 (en) * | 2015-07-15 | 2022-05-13 | 헤래우스 쿼츠 아메리카 엘엘씨 | Process for adding opaque molten quartz to transparent molten quartz |
EP3173386B1 (en) * | 2015-11-25 | 2018-05-02 | Heraeus Quarzglas GmbH & Co. KG | Method for producing a composite body from a material with a high silica content |
US10015879B2 (en) * | 2016-01-27 | 2018-07-03 | Corning Incorporated | Silica content substrate such as for use harsh environment circuits and high frequency antennas |
EP3248950B1 (en) * | 2016-05-24 | 2020-08-05 | Heraeus Quarzglas GmbH & Co. KG | Method for producing an opaque quartz glass containing pores |
JP6878829B2 (en) * | 2016-10-26 | 2021-06-02 | 東ソー株式会社 | Silica powder and highly fluid silica granulated powder and their manufacturing method |
US20180127296A1 (en) | 2016-11-10 | 2018-05-10 | Goodrich Corporation | Additive manufacture of optical components |
JP7162491B2 (en) | 2018-10-17 | 2022-10-28 | 信越石英株式会社 | Method for manufacturing multilayer structure silica glass body |
JP7157932B2 (en) * | 2019-01-11 | 2022-10-21 | 株式会社Sumco | Silica glass crucible manufacturing apparatus and manufacturing method |
CN110064729A (en) * | 2019-05-22 | 2019-07-30 | 惠州市惠阳广杰五金制品有限公司 | Shell membrane manufacture craft |
EP4108641A1 (en) | 2021-06-24 | 2022-12-28 | Heraeus Quarzglas GmbH & Co. KG | Mould made from opaque quartz glass and method of manufacturing the same |
Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2782352A (en) * | 1953-05-29 | 1957-02-19 | Hartford Nat Bank & Trust Co | Alternating-current motor |
US4039909A (en) * | 1975-02-10 | 1977-08-02 | Massachusetts Institute Of Technology | Variable speed electronic motor and the like |
US6222331B1 (en) * | 1997-01-29 | 2001-04-24 | Global Electric Motor Co. Ltd. | Dynamo-electric machines and control and operating system for the same |
US20110285252A1 (en) * | 2010-05-19 | 2011-11-24 | Searete Llc | Motor with rotor-mounted control circuitry |
Family Cites Families (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB1163286A (en) * | 1968-09-03 | 1969-09-04 | Du Pont | Metal-Glass Composite Materials |
JPS59102838A (en) * | 1982-11-29 | 1984-06-14 | Toshiba Ceramics Co Ltd | Devitrification-resistant molded article of fused quartz |
US6012304A (en) * | 1991-09-30 | 2000-01-11 | Loxley; Ted A. | Sintered quartz glass products and methods for making same |
CA2402678A1 (en) * | 2001-09-12 | 2003-03-12 | Kazuma Niume | Coating solution for forming transparent silica coating film and method for producing transparent silica coating |
DE102004051846B4 (en) | 2004-08-23 | 2009-11-05 | Heraeus Quarzglas Gmbh & Co. Kg | Component with a reflector layer and method for its production |
DE102006032687B4 (en) * | 2006-07-13 | 2009-06-10 | Technische Universität Clausthal | Pressings and slip die casting process for the production of compacts |
DE102006046619A1 (en) | 2006-09-29 | 2008-04-03 | Heraeus Quarzglas Gmbh & Co. Kg | Coatable silicon dioxide slip used in the production of layered quartz glass contains a dispersion liquid and amorphous nano-particles with a specified particle size of less |
DE102008030310B3 (en) | 2008-06-30 | 2009-06-18 | Heraeus Quarzglas Gmbh & Co. Kg | Process to fabricate quartz glass crucible with coarse silicon dioxide grains under barrier layer of fine grains |
DE102009049032B3 (en) | 2009-10-10 | 2011-03-24 | Heraeus Quarzglas Gmbh & Co. Kg | Process for producing a coated component of quartz glass |
-
2013
- 2013-11-28 EP EP13194963.8A patent/EP2878584B1/en active Active
-
2014
- 2014-09-08 US US14/391,970 patent/US20150364978A1/en not_active Abandoned
- 2014-11-17 US US14/543,718 patent/US9680360B2/en active Active
- 2014-11-27 KR KR1020140167461A patent/KR101649523B1/en active IP Right Grant
- 2014-11-28 JP JP2014242193A patent/JP5940134B2/en active Active
- 2014-11-28 CN CN201410707275.9A patent/CN104671670B/en active Active
Patent Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2782352A (en) * | 1953-05-29 | 1957-02-19 | Hartford Nat Bank & Trust Co | Alternating-current motor |
US4039909A (en) * | 1975-02-10 | 1977-08-02 | Massachusetts Institute Of Technology | Variable speed electronic motor and the like |
US6222331B1 (en) * | 1997-01-29 | 2001-04-24 | Global Electric Motor Co. Ltd. | Dynamo-electric machines and control and operating system for the same |
US20110285252A1 (en) * | 2010-05-19 | 2011-11-24 | Searete Llc | Motor with rotor-mounted control circuitry |
Cited By (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US10916999B2 (en) | 2013-03-19 | 2021-02-09 | Intellitech Pty Ltd | Device and method for using a magnetic clutch in BLDC motors |
US20180375414A1 (en) * | 2015-10-15 | 2018-12-27 | Vastech Holdings Ltd. | Electric motor |
US10910934B2 (en) * | 2015-10-15 | 2021-02-02 | Vastech Holdings Ltd. | Electric motor |
US11909263B1 (en) | 2016-10-19 | 2024-02-20 | Waymo Llc | Planar rotary transformer |
US20200106318A1 (en) * | 2016-10-28 | 2020-04-02 | Waymo Llc | Devices and Methods for Driving a Rotary Platform |
CN113965022A (en) * | 2016-10-28 | 2022-01-21 | 伟摩有限责任公司 | Apparatus and method for driving a rotating platform |
US11462983B2 (en) | 2017-12-28 | 2022-10-04 | Intellitech Pty Ltd | Electric motor |
Also Published As
Publication number | Publication date |
---|---|
US9680360B2 (en) | 2017-06-13 |
KR101649523B1 (en) | 2016-08-19 |
JP5940134B2 (en) | 2016-06-29 |
CN104671670B (en) | 2018-02-06 |
JP2015105229A (en) | 2015-06-08 |
KR20150062143A (en) | 2015-06-05 |
CN104671670A (en) | 2015-06-03 |
US20150143848A1 (en) | 2015-05-28 |
EP2878584A1 (en) | 2015-06-03 |
EP2878584B1 (en) | 2017-01-04 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US20150364978A1 (en) | Electric Machine | |
KR100215534B1 (en) | Dual-stator induction synchronous motor | |
EP3151396B1 (en) | Rotary electric machine controller and system | |
EP3044860B1 (en) | Electric machine | |
US7134180B2 (en) | Method for providing slip energy control in permanent magnet electrical machines | |
US7915869B2 (en) | Single stage starter/generator with rotor quadrature AC excitation | |
US9543876B2 (en) | Three phase flux switching generator in a three stage wound field synchronous machine | |
US7863868B2 (en) | Generator with quadrature AC excitation | |
CN106416051B (en) | Motor drive | |
US9595857B2 (en) | Electrical machine | |
US20160049838A1 (en) | Synchronous machine | |
WO2007105319A1 (en) | Electric power generator, method for generating electric power, and motor | |
US20150008777A1 (en) | Synchronous electric machine | |
CN107846128A (en) | DC brushless motor and use its electric boosting steering system | |
CN110739891B (en) | Electric excitation synchronous reluctance brushless power generation system | |
WO2014067928A1 (en) | A power generator for a hydro turbine | |
JP5301905B2 (en) | Multi-phase rotating electrical machine drive device, multi-phase generator converter, multi-phase rotating electrical machine, and rotating electrical machine drive system | |
US20040164701A1 (en) | Electrodynamic machines and components therefor and methods of making and using same | |
US20040164695A1 (en) | Electrodynamic machines and components therefor and methods of making and using same | |
US1259295A (en) | Starting synchronous machines. | |
KR20230119793A (en) | Power Generator with Multiple Pole Number | |
RU2249291C1 (en) | Multifunction stator winding of induction generator | |
JPH06245450A (en) | Synchronous motor | |
Munir | Electrical Machines and Adjustable Speed Drives | |
JPH03261355A (en) | Synchronous induction motor of two or more stators |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
AS | Assignment |
Owner name: NRG TECH LTD., BULGARIA Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:PETKANCHIN, LACHEZAR LAZAROV;REEL/FRAME:033973/0789 Effective date: 20141006 |
|
STCB | Information on status: application discontinuation |
Free format text: ABANDONED -- FAILURE TO RESPOND TO AN OFFICE ACTION |