US20100084865A1 - Stator controlled induction generators with short-circuited rotor - Google Patents
Stator controlled induction generators with short-circuited rotor Download PDFInfo
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- US20100084865A1 US20100084865A1 US12/634,454 US63445409A US2010084865A1 US 20100084865 A1 US20100084865 A1 US 20100084865A1 US 63445409 A US63445409 A US 63445409A US 2010084865 A1 US2010084865 A1 US 2010084865A1
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- stator
- voltage
- grid
- generator
- reactive power
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02P—CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS
- H02P9/00—Arrangements for controlling electric generators for the purpose of obtaining a desired output
- H02P9/10—Control effected upon generator excitation circuit to reduce harmful effects of overloads or transients, e.g. sudden application of load, sudden removal of load, sudden change of load
- H02P9/105—Control effected upon generator excitation circuit to reduce harmful effects of overloads or transients, e.g. sudden application of load, sudden removal of load, sudden change of load for increasing the stability
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J3/00—Circuit arrangements for ac mains or ac distribution networks
- H02J3/18—Arrangements for adjusting, eliminating or compensating reactive power in networks
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J3/00—Circuit arrangements for ac mains or ac distribution networks
- H02J3/38—Arrangements for parallely feeding a single network by two or more generators, converters or transformers
- H02J3/381—Dispersed generators
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02P—CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS
- H02P2101/00—Special adaptation of control arrangements for generators
- H02P2101/15—Special adaptation of control arrangements for generators for wind-driven turbines
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- 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
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E40/00—Technologies for an efficient electrical power generation, transmission or distribution
- Y02E40/30—Reactive power compensation
Definitions
- the present invention refers, in general, to an asynchronous short-circuited rotor generator, or induction generator, connectable to a turbine, such as a wind turbine, to generate electric power that is delivered to an electric power distribution grid.
- a turbine such as a wind turbine
- the system also applies to a motor.
- Asynchronous short-circuited rotor generators i.e., squirrel cage
- squirrel cage generators also have disadvantages, such as high current demand during startup requiring a soft start function, a minimal ability to vary the rotational speed of the turbine because of a stiff characteristic torque versus rotational speed in the stable operation region, with resulting significant oscillations of the electromagnetic torque and of the active power transmitted to the electrical system, the inability to meet a requirement for dynamic reactive power exchange from the distribution grid for proper operation, the inability of starting up and operating as a stand-alone system, the inability to be insulated from the external power oscillations from the distribution grid, and the inability to damp such power oscillations.
- the present invention resolves or reduces one or more of the disadvantages explained above by providing a short-circuited rotor generator in which the stator of the generator is connected in series with the electric power distribution grid through a first winding of a transformer.
- the generator is connectable to a turbine, such as a wind turbine.
- a turbine such as a wind turbine.
- An object of the invention is to connect the stator of a squirrel cage generator or motor in series with an electric power distribution grid through a first winding of a transformer.
- the voltage applied to a second winding of the transformer is controlled through a transformer side electric power converter; consequently, the voltage level of the generator's stator is controlled.
- stator of the generator or motor is also connected to the same distribution grid through a stator side electric power converter connected by a direct current link to the transformer side electric power converter.
- a further object of the invention is to provide a short-circuited rotor generator or motor with many different modes of operation allowing it to continue to operate when one or more of the converters fail.
- Another object of the invention is to allow a smooth connection of the generator or motor to the electric power distribution grid, increasing the quality of the electrical production during this period.
- Another object of the invention is to permit the short-circuited rotor machine to continue the supply of electric power or operate as a motor when voltage variations occur on the electric power distribution grid, both in balanced as well as unbalanced operating conditions of the generator.
- a further object of the invention is to contribute to the stability of the distribution grid by providing reactive power to the grid.
- Yet another object of the invention is that the generator or motor be capable of dynamically swapping reactive power with the distribution grid, regardless of the amount of load on the generator.
- Another object of the invention is that the generator be capable of generating a voltage of nominal value at its output when the electric power distribution grid is not available.
- Still another object of the invention is that the generator coupled to a wind generator is capable of being connected to the electric distribution grid when wind speed is low. Consequently, sites with low wind resources can be used with the short-circuited rotor generator according to the invention.
- Yet another object of the invention is to be able to operate with at least a small amount of speed variation to permit the recovery of the torque oscillations reducing stresses and loads and increasing the mechanical performance.
- Another object of the invention is to retain ruggedness and reliability of asynchronous short-circuited rotor generators and motors as well as a large capacity for transitory overloads.
- Another object of the invention is to provide an apparatus and method that can effectively retrofit already installed short-circuited rotor generators or motors to make them compliant with new regulations.
- FIG. 3 is a vector diagram illustrating how the reactive power can be dynamically varied for two different working points of the generator according to the invention
- FIG. 4 is a vector diagram illustrating the soft start function of a generator or motor according to the invention.
- FIG. 7 is a block diagram illustrating a preferred embodiment of controller for the stator side inverter.
- FIG. 1 is a block diagram illustrating a preferred embodiment of a generator or motor system 27 according to the invention.
- the generator system 27 is incorporated into a wind turbine generator 10 , which includes a turbine 12 and generator system 27 .
- Generator system 27 includes a generator 11 , often referred to as an induction generator, and a controller 30 .
- Generator 11 includes a rotor 13 and a stator 14 .
- System 10 preferably is a wind turbine system, and generator 11 preferably is a shorted-rotor generator 11 .
- Turbine 12 is connectable to generator 11 in such a way that the turbine is coupled to the rotor 13 that turns inside stator 14 of the generator 11 . Power produced by system 10 is fed to a power grid 22 .
- the generator system 27 controls the voltage V s applied to the stator by injecting a voltage V i into the stator/grid connection via transformer 15 using a novel control system.
- V s applied to the stator
- V i voltage
- transformer 15 uses a novel control system.
- Generator controller 30 includes transformer 15 , a first electric power converter 16 , a second electrical power converter 17 , a direct current link 33 , a filter 18 , a first controller module 20 , a second controller module 21 , a generator/transformer switch 34 , a transformer/grid switch 35 , a stator/converter switch 31 , and an inductance 23 .
- Transformer 15 includes a first winding 15 - 1 and a second winding 15 - 2 .
- Direct current link 33 includes a capacitor 19 , a resistor 24 , and a switch 25 .
- Filter 18 includes an inductor 36 and a capacitor 37 .
- First controller module 20 includes a microprocessor 40 and memory 41
- second controller module 21 includes a microprocessor 42 and memory 43 .
- Stator 14 is connected in series to a first end 44 of first winding 15 - 1 of transformer 15 , and electric power distribution grid 22 is connected to the second end 45 of the first winding 15 - 1 of the transformer 15 .
- Stator 14 is connected to an input 47 of a first electric power converter 16 , the output 50 of which is connected in cascade, using a direct current connection, to an input 52 of second electric power converter 17 , which has an output 48 connected to second winding 15 - 2 of the transformer 15 through filter 18 .
- Capacitor 19 is connected across direct current link nodes 56 and 57 . Capacitor 19 stores electric energy in accordance with the active power swapped between first converter 16 and second converter 17 .
- resistance 24 is connected through switch 25 across direct current link nodes 56 and 57 .
- Resistor 24 and switch 25 are used to ensure that the maximum voltage levels of the direct current link are not exceeded in the different modes of operation.
- First electric power converter 16 transforms an essentially fixed frequency alternating current deviated from the stator/grid electrical path 32 into direct current; subsequently, the second converter 17 transforms the direct current from the DC link to alternating current at the frequency of the grid. In this way, a portion of the total power delivered by the generator 11 is transferred between the generator's stator and the distribution grid 22 .
- the distribution grid 22 can supply electric power to the generator stator via electrical path 32 and also through the second power converter 17 and first electric power converter 16 . That is, electric power can flow bi-directionally through the connections 32 , 60 between the stator and the distribution grid 22 .
- the system of the invention is applicable not only to a generator, but is also applicable to a motor.
- the total electric power output from the generator 11 is obtained at the grid 22 by adding the partial electric power transfers via the path 32 and 60 , i.e., power converter 16 , DC link, and power converter 17 , to the rest of electric power generated by the generator 11 , i.e., power injected at the point 44 via transformer 15 .
- the first converter 16 includes a set of switching elements, symbolized by switch 62 and diode 63 , each of which has a control terminal 65 through which an on and/or off signal is applied.
- first controller module 20 generates and supplies the switching signals to first converter 16 via line 67 , and to achieve this, the first controller 20 calculates and/or receives a signal V dc proportional to the voltage in the DC link 33 , a signal i p proportional to the current at node 47 , a signal i g proportional to the current output, and a signal V s proportional to the voltage at the stator.
- a DC link voltage reference signal V* dc and a reactive power reference signal Q* 39 are also applied to controller 20 . These reference signals provide the set points for the DC link voltage and the reactive power at node 39 , respectively.
- the DC link voltage V dc is determined by external parameters.
- the desired value of Q* 39 is zero so as to minimize the current at node 39 .
- the manner in which the system according to the invention uses the set points to control V dc and Q 39 will be described below.
- the first controller 20 includes a memory 41 that stores a control algorithm utilized by microprocessor 40 , which algorithm may be a vector control algorithm, a direct power control algorithm, or any other suitable control algorithm, with which the voltage of the DC link, V dc , is regulated to permit instantaneous transfer of active power through electrical path 60 , and the reactive power at node 39 , Q 39 , is regulated to guarantee that V s and i g are aligned which naturally decouples the effects of V id and V iq . That is, V id affects only the value of
- second converter 17 includes a set of switching elements, symbolized by switch 72 and diode 73 , each of which has a control terminal 75 through which an on and/or off signal is applied.
- Second controller module 21 generates and supplies the on or off signals to second converter 17 via line 77 .
- second controller 21 calculates and/or receives a signal V s proportional to the voltage of the stator 14 , a signal i s proportional to the current of the stator 14 , a signal V g proportional to the distribution grid 22 voltage, and a signal i g proportional to generator current applied grid at output 22 .
- and a total reactive power reference signal Q* g also are applied to grid side inverter controller 21 .
- These reference signals provide the set points for the absolute value of the stator voltage
- is determined by a higher level control loop as known in the art.
- the set point Q* g is a reactive power value desired to be output as determined by the operating conditions of the grid.
- Second controller 21 stores an algorithm in memory 43 utilized by microprocessor 42 to regulate the total reactive power Q g following a control strategy that utilizes reference value Q* g .
- Memory 43 of second controller 21 also stores an algorithm utilized by microprocessor 42 to regulate the modulus of the voltage resulting from or applied to the generator's stator 14 , following a control strategy that utilizes reference value
- These algorithms may be a vector control algorithm, such as a voltage oriented control algorithm, a direct power control algorithm, or any other suitable control algorithm.
- first controller 20 and second controller 21 govern the first 16 and second 17 converters, respectively, in such a way that they directly control the absolute voltage applied to the generator's stator 14 and the total reactive power applied to the grid, therefore making the system according to the invention much more stable under grid variations and better able to strengthen the grid as required by grid code requirements.
- V s is the stator voltage
- V g is the grid voltage
- V i is the voltage injected via transformer 15
- i s is the stator current
- i g is the grid current
- i p is the current flowing at node 47
- ⁇ ig is the angle between ⁇ and the grid current i g , which angle, in this operating mode, is the same as ⁇ vs , the angle between ⁇ , and the stator voltage V s .
- FIG. 3 is a vector diagram illustrating how the reactive power can be dynamically varied for two different working points of the generator according to the invention. Since the purpose of this figure is to illustrate how the reactive power is adjusted, the absolute value of the stator voltage V s and the grid voltage V g are assumed to be the same so as not to unduly complicate the figure. However, those skilled in the art will recognize that all of these variables can change simultaneously.
- the stator current i s must be leading in relation to the stator voltage V g .
- controller 20 to add an i pd (2) and an i pq (2) as shown to hold V dc to V dc * and Q 39 to Q* 39 .
- V s (2) has a smaller negative value to yield a larger V s (2) and an i s (2) that is leading less, resulting in a small reactive power being absorbed.
- the system applies, via controller 21 and converter 17 , a V i (2) as shown via the transformer 15 .
- This causes i g (2) to rise, which requires controller 20 to apply a larger i p (2) as shown to keep the grid current and grid voltage aligned.
- FIG. 6 is a block diagram illustrating a preferred embodiment of controller for the stator side inverter 20 .
- Stator side controller 20 comprises comparators 502 and 506 , PI controllers 504 and 508 , rotational transformation 510 , switching pattern generator 512 , which preferably is a pulse width modulator, and argument calculator 516 .
- the V dc * reference signal and the measured V dc signal are input into comparator 502 , which outputs a signal representative of their difference to PI controller 504 .
- the Q 39 * reference signal and measured Q 39 signal are input into comparator 506 which outputs a signal representative of their difference to PI controller 508 .
- PI controller 504 is designed to guarantee that the set point V dc * is reached with the specific dynamics of the generator 27 and outputs the required value reference of i* pd to reach this set point.
- PI controller 508 is designed to guarantee that the set point Q 39 * is reached with the specific dynamics of the generator 27 and outputs the required value reference of i* pq to reach this set point.
- Current controller 509 provides an inner control loop that compares the measured value i p to i* pd and i* pq and outputs V pd and V pq to the rotational transformation 510 .
- Argument calculator 516 calculates the angle of V s and outputs this angle ⁇ vs to the rotational transformer 510 .
- rotational transformer 510 rotates the coordinates of V pd and V pq from the synchronous coordinates to the stationary coordinates ⁇ and ⁇ .
- the resulting current components Vi p ⁇ and V p ⁇ are applied to switching pattern generator 512 which applies an appropriate duty cycle generator, such as pulse width modulation, to the voltages to determine the drive signals 67 to be applied to the converter 16 .
- FIG. 7 is a block diagram illustrating a preferred embodiment of controller for the grid side inverter. This example assumes a control algorithm using current oriented vector control, though other control systems and algorithms may be used.
- Grid side controller 21 comprises comparators 702 and 706 , PI controllers 704 and 708 , rotational transformation 710 , switching pattern generator 712 , which preferably is a pulse width modulator, and argument calculator 716 .
- the V s * reference signal and the measured V s signal are input into comparator 702 , which outputs a signal representative of their difference to PI controller 704 .
- the Q g * reference signal and measured Q g signal are input into comparator 706 , which outputs a signal representative of their difference to PI controller 708 .
- PI controller 704 is designed to guarantee that the set point V s * is reached with the specific dynamics of the generator 27 and outputs the required value of V id to reach this set point.
- PI controller 708 is designed to guarantee that the set point Q g * is reached with the specific dynamics of the generator 27 and outputs the required value of to reach this set point.
- Argument calculator 716 calculates the angle of i g and outputs this angle ⁇ ig to the rotational transformer 710 . Using the angle ⁇ ig , rotational transformer 710 rotates the coordinates of V id and from the synchronous coordinates to the stationary coordinates ⁇ and ⁇ . The resulting voltages V i ⁇ and V i ⁇ are applied to switching pattern generator 712 , which applies an appropriate duty cycle generator, such as pulse width modulation, to the voltages to determine the drive signals 77 to be applied to the converter 17 .
- an appropriate duty cycle generator such as pulse width modulation
- both the first and second controllers 20 , 21 can work in coordinated mode or either of them can work with the other one disconnected, or even neither of the two activated, the generating capacities being reduced in each case.
- the voltage V i of the second converter 17 is vectorally added to the voltage V g of the distribution grid 22 .
- the present invention can be implemented in a variety of computers that include microprocessors, a computer-readable storage means that includes volatile and non-volatile memory elements, and/or storage elements.
- the logic of the computer hardware that cooperates with various sets of instructions is applied to the data in order to carry out the previously described functions and to generate output information.
- the programs used for the computer hardware preferably can be implemented in various programming languages, including a high-level-process- or object-oriented programming language for communicating with a computer system.
- Each computer program preferably is stored in a storage means or device (e.g., ROM or magnetic disc) that can be read by a general use or special use programmable computer for configuring and operating the computer when the storage means or device is read by the computer in order to execute the procedures described above.
- a storage means or device e.g., ROM or magnetic disc
- the first and second controller can be considered as being implemented as a computer-readable storage medium, configured with a computer program, where the storage medium thus configured makes the computer operate in a specific, predefined way.
- the two microprocessors of the first and second controller can be in communication or encapsulated in a single component.
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Abstract
A generator is connectable to a turbine for generating electric power or a motor. An electric power generator system or a motor comprises an asynchronous short-circuited rotor generator or motor comprising a stator, a rotor, and a transformer having a first winding and a second winding, the first winding having a first end and a second end. The stator and the transformer are connectable in series with an electric power distribution grid.
Description
- This Application is a divisional application of U.S. patent application Ser. No. 11/716,438 filed Mar. 9, 2007, which claims priority to the application filed in Spain under PCT Application No. PCT/ES2006/000721 on Dec. 28, 2006. The foregoing applications are hereby incorporated by reference to the same extent as though fully disclosed herein.
- The present invention refers, in general, to an asynchronous short-circuited rotor generator, or induction generator, connectable to a turbine, such as a wind turbine, to generate electric power that is delivered to an electric power distribution grid. The system also applies to a motor.
- It is known in the state of the art that currently there are many asynchronous short-circuited rotor generators, such as the so-called squirrel cage rotor, coupled to turbines, such as wind turbines, and connected directly to a three-phase electric power distribution grid by voltage step-up transformers. Consequently, said configuration of turbine connected to a generator is used to produce electric power that reaches end users through the three-phase electric power distribution grid.
- Asynchronous short-circuited rotor generators, i.e., squirrel cage, are widely used because they are simple, robust, and relatively inexpensive. However, such squirrel cage generators also have disadvantages, such as high current demand during startup requiring a soft start function, a minimal ability to vary the rotational speed of the turbine because of a stiff characteristic torque versus rotational speed in the stable operation region, with resulting significant oscillations of the electromagnetic torque and of the active power transmitted to the electrical system, the inability to meet a requirement for dynamic reactive power exchange from the distribution grid for proper operation, the inability of starting up and operating as a stand-alone system, the inability to be insulated from the external power oscillations from the distribution grid, and the inability to damp such power oscillations.
- It would be highly desirable to have a squirrel-cage generator which retained the features of simplicity, robustness. and relative low cost without the disadvantages discussed above.
- The present invention resolves or reduces one or more of the disadvantages explained above by providing a short-circuited rotor generator in which the stator of the generator is connected in series with the electric power distribution grid through a first winding of a transformer. Preferably, the generator is connectable to a turbine, such as a wind turbine. Those skilled in the art will also recognize that the principles of the invention also apply to a squirrel cage motor.
- An object of the invention is to connect the stator of a squirrel cage generator or motor in series with an electric power distribution grid through a first winding of a transformer. Preferably, the voltage applied to a second winding of the transformer is controlled through a transformer side electric power converter; consequently, the voltage level of the generator's stator is controlled.
- Preferably, the stator of the generator or motor is also connected to the same distribution grid through a stator side electric power converter connected by a direct current link to the transformer side electric power converter.
- The above-described dual connection makes it possible to increase the overall performance of the electric generator or motor by reducing the losses in the iron of the generator.
- A further object of the invention is to provide a short-circuited rotor generator or motor with many different modes of operation allowing it to continue to operate when one or more of the converters fail.
- Another object of the invention is to allow a smooth connection of the generator or motor to the electric power distribution grid, increasing the quality of the electrical production during this period.
- Another object of the invention is to permit the short-circuited rotor machine to continue the supply of electric power or operate as a motor when voltage variations occur on the electric power distribution grid, both in balanced as well as unbalanced operating conditions of the generator. A further object of the invention is to contribute to the stability of the distribution grid by providing reactive power to the grid.
- Yet another object of the invention is that the generator or motor be capable of dynamically swapping reactive power with the distribution grid, regardless of the amount of load on the generator.
- Another object of the invention is that the generator be capable of generating a voltage of nominal value at its output when the electric power distribution grid is not available.
- Still another object of the invention is that the generator coupled to a wind generator is capable of being connected to the electric distribution grid when wind speed is low. Consequently, sites with low wind resources can be used with the short-circuited rotor generator according to the invention.
- Yet another object of the invention is to be able to operate with at least a small amount of speed variation to permit the recovery of the torque oscillations reducing stresses and loads and increasing the mechanical performance.
- Another object of the invention is to retain ruggedness and reliability of asynchronous short-circuited rotor generators and motors as well as a large capacity for transitory overloads.
- Another object of the invention is to provide an apparatus and method that can effectively retrofit already installed short-circuited rotor generators or motors to make them compliant with new regulations.
- Numerous other features, objects, and advantages of the invention will become apparent from the following description when read in conjunction with the accompanying drawings.
- A more detailed explanation of the invention is given in the following description, based on the attached figures in which:
-
FIG. 1 shows a block diagram of a wind generator according to the invention; -
FIG. 2 shows a vector diagram illustrating the various vectors, vector components, and angles relevant to the invention and showing how the stator voltage may be controlled while injecting a desired reactive power; -
FIG. 3 is a vector diagram illustrating how the reactive power can be dynamically varied for two different working points of the generator according to the invention; -
FIG. 4 is a vector diagram illustrating the soft start function of a generator or motor according to the invention; -
FIG. 5 is a vector diagram illustrating how the generator according to the invention applies the predetermined value of |Vs| corresponding to |V*s| to the stator during voltage dips of the grid voltage; -
FIG. 6 is a block diagram illustrating a preferred embodiment of controller for the grid side inverter; and -
FIG. 7 is a block diagram illustrating a preferred embodiment of controller for the stator side inverter. -
FIG. 1 is a block diagram illustrating a preferred embodiment of a generator ormotor system 27 according to the invention. In this embodiment, thegenerator system 27 is incorporated into awind turbine generator 10, which includes aturbine 12 andgenerator system 27.Generator system 27 includes agenerator 11, often referred to as an induction generator, and acontroller 30.Generator 11 includes arotor 13 and astator 14.System 10 preferably is a wind turbine system, andgenerator 11 preferably is a shorted-rotor generator 11.Turbine 12 is connectable togenerator 11 in such a way that the turbine is coupled to therotor 13 that turns insidestator 14 of thegenerator 11. Power produced bysystem 10 is fed to apower grid 22. As will be seen in detail below, thegenerator system 27 according to the invention controls the voltage Vs applied to the stator by injecting a voltage Vi into the stator/grid connection viatransformer 15 using a novel control system. This and other features of the invention described below results in a generator or motor system that is much more flexible than prior art systems. -
Generator controller 30 includestransformer 15, a firstelectric power converter 16, a secondelectrical power converter 17, adirect current link 33, afilter 18, afirst controller module 20, asecond controller module 21, a generator/transformer switch 34, a transformer/grid switch 35, a stator/converter switch 31, and aninductance 23. Transformer 15 includes a first winding 15-1 and a second winding 15-2. Directcurrent link 33 includes acapacitor 19, aresistor 24, and aswitch 25.Filter 18 includes aninductor 36 and acapacitor 37.First controller module 20 includes amicroprocessor 40 andmemory 41, andsecond controller module 21 includes amicroprocessor 42 andmemory 43. -
Stator 14 is connected in series to afirst end 44 of first winding 15-1 oftransformer 15, and electricpower distribution grid 22 is connected to thesecond end 45 of the first winding 15-1 of thetransformer 15. -
Stator 14 is connected to aninput 47 of a firstelectric power converter 16, theoutput 50 of which is connected in cascade, using a direct current connection, to aninput 52 of secondelectric power converter 17, which has anoutput 48 connected to second winding 15-2 of thetransformer 15 throughfilter 18. -
Capacitor 19 is connected across directcurrent link nodes first converter 16 andsecond converter 17. - Furthermore,
resistance 24 is connected throughswitch 25 across directcurrent link nodes Resistor 24 andswitch 25 are used to ensure that the maximum voltage levels of the direct current link are not exceeded in the different modes of operation. - First
electric power converter 16 transforms an essentially fixed frequency alternating current deviated from the stator/gridelectrical path 32 into direct current; subsequently, thesecond converter 17 transforms the direct current from the DC link to alternating current at the frequency of the grid. In this way, a portion of the total power delivered by thegenerator 11 is transferred between the generator's stator and thedistribution grid 22. - In another mode of operation of
generator 11, thedistribution grid 22 can supply electric power to the generator stator viaelectrical path 32 and also through thesecond power converter 17 and firstelectric power converter 16. That is, electric power can flow bi-directionally through theconnections distribution grid 22. Thus, it is evident to those skilled in the art that the system of the invention is applicable not only to a generator, but is also applicable to a motor. - The total electric power output from the
generator 11 is obtained at thegrid 22 by adding the partial electric power transfers via thepath power converter 16, DC link, andpower converter 17, to the rest of electric power generated by thegenerator 11, i.e., power injected at thepoint 44 viatransformer 15. - The
first converter 16 includes a set of switching elements, symbolized byswitch 62 anddiode 63, each of which has acontrol terminal 65 through which an on and/or off signal is applied. - With reference now to
FIGS. 1 and 2 ,first controller module 20 generates and supplies the switching signals tofirst converter 16 vialine 67, and to achieve this, thefirst controller 20 calculates and/or receives a signal Vdc proportional to the voltage in theDC link 33, a signal ip proportional to the current atnode 47, a signal ig proportional to the current output, and a signal Vs proportional to the voltage at the stator. A DC link voltage reference signal V*dc and a reactive power reference signal Q*39 are also applied tocontroller 20. These reference signals provide the set points for the DC link voltage and the reactive power atnode 39, respectively. As is known in the art, the DC link voltage Vdc is determined by external parameters. For example, in the example of the wind turbine, it is determined by the grid voltage. In the preferred embodiment, the desired value of Q*39 is zero so as to minimize the current atnode 39. The manner in which the system according to the invention uses the set points to control Vdc and Q39 will be described below. - The
first controller 20 includes amemory 41 that stores a control algorithm utilized bymicroprocessor 40, which algorithm may be a vector control algorithm, a direct power control algorithm, or any other suitable control algorithm, with which the voltage of the DC link, Vdc, is regulated to permit instantaneous transfer of active power throughelectrical path 60, and the reactive power atnode 39, Q39, is regulated to guarantee that Vs and ig are aligned which naturally decouples the effects of Vid and Viq. That is, Vid affects only the value of |Vs|, and Viq affects only the value of Qg, the total reactive power applied to the grid. - Similarly,
second converter 17 includes a set of switching elements, symbolized byswitch 72 anddiode 73, each of which has acontrol terminal 75 through which an on and/or off signal is applied. -
Second controller module 21 generates and supplies the on or off signals tosecond converter 17 vialine 77. To achieve this,second controller 21 calculates and/or receives a signal Vs proportional to the voltage of thestator 14, a signal is proportional to the current of thestator 14, a signal Vg proportional to thedistribution grid 22 voltage, and a signal ig proportional to generator current applied grid atoutput 22. An absolute value, also referred to as the modulus, of the stator voltage reference signal |V*s| and a total reactive power reference signal Q*g also are applied to gridside inverter controller 21. These reference signals provide the set points for the absolute value of the stator voltage |Vs| and the total reactive power Qg. As is known in the art, the set point |V*s| is determined by a higher level control loop as known in the art. The set point Q*g is a reactive power value desired to be output as determined by the operating conditions of the grid. -
Second controller 21 stores an algorithm inmemory 43 utilized bymicroprocessor 42 to regulate the total reactive power Qg following a control strategy that utilizes reference value Q*g.Memory 43 ofsecond controller 21 also stores an algorithm utilized bymicroprocessor 42 to regulate the modulus of the voltage resulting from or applied to the generator'sstator 14, following a control strategy that utilizes reference value |V*s|. These algorithms may be a vector control algorithm, such as a voltage oriented control algorithm, a direct power control algorithm, or any other suitable control algorithm. - Consequently,
first controller 20 andsecond controller 21 govern the first 16 and second 17 converters, respectively, in such a way that they directly control the absolute voltage applied to the generator'sstator 14 and the total reactive power applied to the grid, therefore making the system according to the invention much more stable under grid variations and better able to strengthen the grid as required by grid code requirements. - Turning to
FIG. 2 , there is shown a vector diagram illustrating the various vectors, vector components, and angles relevant to the invention and showing how the stator voltage may be controlled while injecting a desired reactive power. In this example, for ease of understanding, the stator voltage Vs and the grid current ig are aligned, which is the preferred operating condition of the system. The vectors, vector components, and angles are illustrated in a stationary coordinate system along the directions α and β. The coordinate system d and q is a synchronous coordinate system with d in the direction of the stator voltage Vs and the grid current ig, and q in a direction orthogonal to the direction the stator voltage Vs and the grid current ig. - In
FIG. 2 , Vs is the stator voltage, Vg is the grid voltage, and Vi is the voltage injected viatransformer 15. Also, is is the stator current, ig is the grid current, and ip is the current flowing atnode 47. θig is the angle between α and the grid current ig, which angle, in this operating mode, is the same as θvs, the angle between α, and the stator voltage Vs. Vid is the component of Vi in the direction of the grid current and the stator voltage, and Viq is the component of Vi in the direction orthogonal to the grid current and the stator voltage, while ipd is the component of ip in the direction of the grid current and stator voltage, and ipq is the component of ip in the direction of the grid current and stator voltage. As will be shown below,controller 20 determines the reference values of i*pd and i*pq to force the system to the set points V*dc and Q*39, andcontroller 21 determines the values of Vid and Viq to force the system to the set points |V*s| and Q*g. -
FIG. 3 is a vector diagram illustrating how the reactive power can be dynamically varied for two different working points of the generator according to the invention. Since the purpose of this figure is to illustrate how the reactive power is adjusted, the absolute value of the stator voltage Vs and the grid voltage Vg are assumed to be the same so as not to unduly complicate the figure. However, those skilled in the art will recognize that all of these variables can change simultaneously. At working point (1), the power factor is unity and Vg (1)=Vs. For a shorted-rotor induction machine, the stator current is must be leading in relation to the stator voltage Vg. The requirement that the active power atnode 47, i.e., Pp=Vs,ipd must be the same as the active power atnode 48, i.e., Pi=Vid, ig requires that ipd is zero because Vid is zero. At working point (2), it is decided to apply a reactive power at thenode 22 which is indicated by the fact that the grid voltage Vg is now out of phase with the grid current ig by an angle φg. The generator is set to this reactive power by applying the shown Viq (2). To keep |Vs| constant, the system adjusts Vid to Vid (2) as shown. The additional reactive power added to the generator output causes ig to increase to ig (2) as shown. This requirescontroller 20 to add an ipd (2) and an ipq (2) as shown to hold Vdc to Vdc* and Q39 to Q*39. -
FIG. 4 is a vector diagram illustrating the soft start function of a generator or motor according to the invention. Three working points of the start process are shown. For all three working points, Vg is the same. At the first working point (1), the stator voltage Vs is made very small by inserting a Vi (not shown so as not to complicate the figure) equal to Vi (1)=Vs (1)−Vg viatransformer 15. Due to the required lag between the stator current and stator voltage, is (1) is nearly 90 degrees leading to the stator voltage indicating the system is absorbing significant reactive power. At the second working point (2), Vs (2) has a smaller negative value to yield a larger Vs (2) and an is (2) that is leading less, resulting in a small reactive power being absorbed. At the third working point (3), Vs (3) is zero to yield Vs (3)=Vg resulting in is (3) lagging only by the nominal amount required by the short-circuited rotor inductive system. -
FIG. 5 is a vector diagram illustrating how the generator according to the invention applies the predetermined value of |Vs| corresponding to |V*s| to the stator during voltage dips of the grid voltage. For simplicity in this figure, Vg is in the same direction as ig. Two working points (1) and (2) are shown. At the first working point (1), Vg (1)=Vs, which is equal to the set point value of the stator voltage, and is has the required lead determined by the machine parameters.Controller 20 applies an appropriate ip (1) due to the fact that the grid current and grid voltage are aligned. At working point (2), the grid voltage Vg suddenly drops. To keep the stator voltage at the set point, the system applies, viacontroller 21 andconverter 17, a Vi (2) as shown via thetransformer 15. This causes ig (2) to rise, which requirescontroller 20 to apply a larger ip (2) as shown to keep the grid current and grid voltage aligned. -
FIG. 6 is a block diagram illustrating a preferred embodiment of controller for thestator side inverter 20. This example assumes a control algorithm using voltage vector oriented vector control, though other control systems and algorithms may be used.Stator side controller 20 comprisescomparators PI controllers rotational transformation 510, switchingpattern generator 512, which preferably is a pulse width modulator, andargument calculator 516. The Vdc* reference signal and the measured Vdc signal are input intocomparator 502, which outputs a signal representative of their difference toPI controller 504. The Q39* reference signal and measured Q39 signal are input intocomparator 506 which outputs a signal representative of their difference toPI controller 508.PI controller 504 is designed to guarantee that the set point Vdc* is reached with the specific dynamics of thegenerator 27 and outputs the required value reference of i*pd to reach this set point.PI controller 508 is designed to guarantee that the set point Q39* is reached with the specific dynamics of thegenerator 27 and outputs the required value reference of i*pq to reach this set point.Current controller 509 provides an inner control loop that compares the measured value ip to i*pd and i*pq and outputs Vpd and Vpq to therotational transformation 510.Argument calculator 516 calculates the angle of Vs and outputs this angle θvs to therotational transformer 510. Using the angle,rotational transformer 510 rotates the coordinates of Vpd and Vpq from the synchronous coordinates to the stationary coordinates α and β. The resulting current components Vipα and Vpβ are applied to switchingpattern generator 512 which applies an appropriate duty cycle generator, such as pulse width modulation, to the voltages to determine the drive signals 67 to be applied to theconverter 16. -
FIG. 7 is a block diagram illustrating a preferred embodiment of controller for the grid side inverter. This example assumes a control algorithm using current oriented vector control, though other control systems and algorithms may be used.Grid side controller 21 comprisescomparators PI controllers rotational transformation 710, switchingpattern generator 712, which preferably is a pulse width modulator, andargument calculator 716. The Vs* reference signal and the measured Vs signal are input intocomparator 702, which outputs a signal representative of their difference toPI controller 704. The Qg* reference signal and measured Qg signal are input intocomparator 706, which outputs a signal representative of their difference toPI controller 708.PI controller 704 is designed to guarantee that the set point Vs* is reached with the specific dynamics of thegenerator 27 and outputs the required value of Vid to reach this set point.PI controller 708 is designed to guarantee that the set point Qg* is reached with the specific dynamics of thegenerator 27 and outputs the required value of to reach this set point.Argument calculator 716 calculates the angle of ig and outputs this angle θig to therotational transformer 710. Using the angle θig,rotational transformer 710 rotates the coordinates of Vid and from the synchronous coordinates to the stationary coordinates α and β. The resulting voltages Viα and Viβ are applied to switchingpattern generator 712, which applies an appropriate duty cycle generator, such as pulse width modulation, to the voltages to determine the drive signals 77 to be applied to theconverter 17. - It should be observed that both the first and
second controllers - The way the voltage resulting from and/or applied to the
stator 14 is governed based on controlling the voltage delivered in series from thesecond converter 17 to theelectric distribution grid 22 through thetransformer 15. The voltage Vi of thesecond converter 17 is vectorally added to the voltage Vg of thedistribution grid 22. - Moreover, it should be observed that the present invention can be implemented in a variety of computers that include microprocessors, a computer-readable storage means that includes volatile and non-volatile memory elements, and/or storage elements. The logic of the computer hardware that cooperates with various sets of instructions is applied to the data in order to carry out the previously described functions and to generate output information. The programs used for the computer hardware, by way of example, preferably can be implemented in various programming languages, including a high-level-process- or object-oriented programming language for communicating with a computer system. Each computer program preferably is stored in a storage means or device (e.g., ROM or magnetic disc) that can be read by a general use or special use programmable computer for configuring and operating the computer when the storage means or device is read by the computer in order to execute the procedures described above. Moreover, the first and second controller can be considered as being implemented as a computer-readable storage medium, configured with a computer program, where the storage medium thus configured makes the computer operate in a specific, predefined way.
- The two microprocessors of the first and second controller can be in communication or encapsulated in a single component.
- There has been described a novel short-circuited rotor (squirrel cage) generator or motor. Now that the apparatus and processes of the invention have been described, those skilled in the art may make many variations. It should be understood that the particular embodiments shown in the drawings and described within this specification are for purposes of example and should not be construed to limit the invention, which will be described in the claims below. The description, as it has been explained, is not intended to be exhaustive of the invention or to limit the invention to the specific form described. Many modifications and variations are possible in light of the foregoing examples, without going beyond the spirit and scope of the following claims. For example, many different controllers other than PI controllers may be used. It is also evident that those skilled in the art may now make numerous uses and modifications of the specific embodiments described, without departing from the inventive concepts. It is further evident that the methods recited may, in many instances, be performed in a different order; or equivalent components may be used and/or equivalent processes may be substituted for the various processes described. Consequently, the invention is to be construed as embracing each and every novel feature and novel combination of features present in and/or possessed by the invention herein described.
Claims (26)
1. An asynchronous short-circuited rotor generator for generating electric power wherein a stator is connected in series to a first end of a first winding of a transformer, and an electric power distribution grid is connected to the second end of the first winding of the transformer.
2. An electric power generator system or motor comprising:
a short-circuited rotor induction generator or motor comprising a stator and a rotor;
a transformer having a first winding and a second winding, said first winding having a first end and a second end; and
wherein said stator and said transformer are connectable in series with an electric power distribution grid.
3-12. (canceled)
13. A method of generating electrical power, said method comprising:
generating electrical power using a short-circuited rotor induction generator comprising a stator and a rotor;
connecting a first winding of a transformer in series between said stator and an electric power distribution grid; and
flowing power between said stator and said electric power distribution grid via said transformer.
14. A method as in claim 13 , and further comprising:
connecting a first converter, a direct current link, and a second converter in series between said stator and a second winding of said transformer; and
regulating one of the current between said first converter and said stator, and the sum of the reactive power of said stator and the reactive power of said converter.
15-19. (canceled)
20. A system for controlling: a short-circuited rotor induction generator providing electrical power to an electric distribution grid, or a motor connected to said grid, said generator or motor having a stator and a rotor, said system comprising a media readable by a processing unit, said media containing instructions for directing said processing unit to regulate one or more of the voltage of said stator independent of the voltage of said electric distribution grid, and the reactive power applied to said grid by said generator or motor.
21. A system as in claim 20 wherein said instructions further comprise instructions for comparing a voltage on a DC bus between said stator and said grid with a DC bus reference voltage to regulate the transfer of active power to said grid via said DC bus.
22. A system as in claim 20 wherein said instructions further comprise instructions for comparing the voltage on said stator with a stator reference voltage to determine a voltage component in the direction aligned with the current of said grid.
23. A system as in claim 20 wherein said instructions further comprise instructions for comparing the total reactive power delivered to said grid with a total reactive power reference to determine a voltage component in the direction orthogonal with the current of said grid.
24. A method of controlling a wind turbine generator connected to a grid, said turbine including a short-circuited rotor induction generator system having a stator and a rotor, said method comprising:
generating a voltage; and
injecting said voltage in series between said stator and said grid.
25. A method as in claim 24 wherein said voltage has a component oriented in the direction of the grid current, which component injects active power into said grid.
26. A method as in clam 24 wherein said voltage has a component in quadrature with the grid current, which component injects reactive power into said grid.
27. A method as in claim 24 wherein said generating comprises comparing the total reactive power applied to said grid to a reference reactive power to produce a reactive power error signal, and using said reactive power error signal to determine a value of said injected voltage orthogonal to the current of said grid.
28. A method as in claim 24 wherein said generating comprises comparing the voltage applied to said stator to a reference stator voltage to produce a stator voltage error signal.
29. A method as in claim 28 wherein said generating further comprises using said stator voltage error signal to determine the value of said injected voltage in a direction aligned with the grid current.
30. A method as in claim 24 wherein said generator system further includes a first converter, a DC link, and a second converter connected between said stator and said grid, and wherein said generating comprises comparing a measured DC voltage of said DC link to a reference DC voltage to provide a DC error signal.
31. A method as in claim 29 wherein said generating further comprises using said DC error signal to determine a component of the current between said first converter and said stator in a direction aligned with the stator voltage.
32. A method of operating a short-circuited rotor induction power generator or motor connected to a power distribution grid, said generator or motor comprising a rotor and a stator, said method comprising controlling the voltage applied to said stator independent of the voltage of said grid.
33. A method as in claim 32 wherein said stator voltage is held constant.
34. A method as in claim 32 wherein said controlling the voltage applied to said stator comprises injecting a voltage between said stator and said grid.
35. A method as in claim 34 wherein said injecting is performed by applying said voltage via a transformer connected between said stator and said grid.
36. A method as in claim 34 wherein said controlling comprises comparing the voltage applied to said stator to a reference stator voltage to produce a stator voltage error signal.
37. A method as in claim 36 wherein said generating further comprises using said stator voltage error signal to determine the value of said injected voltage in a direction aligned with the grid current.
38. A method as in claim 34 wherein said generating further comprises comparing the total reactive power applied to said grid to a reference reactive power to produce a reactive power error signal.
39. A method as in claim 38 wherein said generating further comprises using said reactive power error signal to determine a value of said injected voltage orthogonal to the current of said grid.
Priority Applications (1)
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US12/634,454 US20100084865A1 (en) | 2006-12-28 | 2009-12-09 | Stator controlled induction generators with short-circuited rotor |
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ESPCT/ES2006/000721 | 2006-12-28 | ||
PCT/ES2006/000721 WO2008081049A1 (en) | 2006-12-28 | 2006-12-28 | Asynchronous generator with control of the voltage applied to the stator |
US11/716,438 US7652387B2 (en) | 2006-12-28 | 2007-03-09 | Stator controlled induction generators with short-circuited rotor |
US12/634,454 US20100084865A1 (en) | 2006-12-28 | 2009-12-09 | Stator controlled induction generators with short-circuited rotor |
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US11/716,438 Division US7652387B2 (en) | 2006-12-28 | 2007-03-09 | Stator controlled induction generators with short-circuited rotor |
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US12/634,454 Abandoned US20100084865A1 (en) | 2006-12-28 | 2009-12-09 | Stator controlled induction generators with short-circuited rotor |
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Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20110018270A1 (en) * | 2006-12-22 | 2011-01-27 | Wind To Power System, S.L. | Doubly-controlled asynchronous generator |
US20110109085A1 (en) * | 2009-11-10 | 2011-05-12 | Nelson Robert J | Power Oscillation Damping Employing a Full or Partial Conversion Wind Turbine |
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US9705440B2 (en) * | 2015-07-16 | 2017-07-11 | Hamilton Sundstrand Corporation | Fault tolerant electric power generating system |
US9973123B2 (en) * | 2016-03-16 | 2018-05-15 | General Electric Company | System and method for controlling a generator |
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US10784685B2 (en) | 2017-05-08 | 2020-09-22 | General Electric Company | Electrical power systems and subsystems |
DE102017208093A1 (en) * | 2017-05-15 | 2018-11-15 | Audi Ag | Method for operating an electric machine and electric machine |
WO2019094179A1 (en) * | 2017-11-13 | 2019-05-16 | General Electric Company | A power generation system having a direct current link connected to a ground terminal |
Citations (43)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2292171A (en) * | 1939-08-11 | 1942-08-04 | Gen Electric | Electric valve operated motor |
US2585392A (en) * | 1948-03-19 | 1952-02-12 | Jeumont Forges Const Elec | Monopolyphase frequency converter group |
US2859005A (en) * | 1952-11-21 | 1958-11-04 | Bendix Aviat Corp | Monitoring system for aircraft auto pilots |
US2916632A (en) * | 1956-05-05 | 1959-12-08 | Asea Ab | Means for controlling the position of a radiating body |
US3048771A (en) * | 1957-04-25 | 1962-08-07 | Standard Electrical Products C | Regulator |
US3211981A (en) * | 1957-04-25 | 1965-10-12 | Staco Inc | Motor control system with direct current braking |
US3469134A (en) * | 1965-07-31 | 1969-09-23 | Lloyd Dynamowerke Gmbh | Electrical machines |
US3591844A (en) * | 1967-09-26 | 1971-07-06 | Licentia Gmbh | Electrical apparatus for rotating a turbogenerator shaft |
US4341989A (en) * | 1979-03-08 | 1982-07-27 | Elmekano I Lulea Ab | Device for phase compensation and excitation of an asynchronous machine operating as a generator |
US4651265A (en) * | 1985-07-29 | 1987-03-17 | Westinghouse Electric Corp. | Active power conditioner system |
US4761602A (en) * | 1985-01-22 | 1988-08-02 | Gregory Leibovich | Compound short-circuit induction machine and method of its control |
US5083039A (en) * | 1991-02-01 | 1992-01-21 | U.S. Windpower, Inc. | Variable speed wind turbine |
US5166597A (en) * | 1991-08-08 | 1992-11-24 | Electric Power Research Institute | Phase-shifting transformer system |
US5198746A (en) * | 1991-09-16 | 1993-03-30 | Westinghouse Electric Corp. | Transmission line dynamic impedance compensation system |
US5309346A (en) * | 1991-09-16 | 1994-05-03 | Westinghouse Electric Corp. | Transmission line fault current dynamic inverter control |
US5329222A (en) * | 1992-11-30 | 1994-07-12 | Westinghouse Electric Corporation | Apparatus and method for dynamic voltage restoration of utility distribution networks |
US5343139A (en) * | 1992-01-31 | 1994-08-30 | Westinghouse Electric Corporation | Generalized fast, power flow controller |
US5355295A (en) * | 1993-08-19 | 1994-10-11 | Westinghouse Electric Corporation | Series-parallel active power line conditioner utilizing temporary link energy boosting for enhanced peak voltage regulation capability |
US5469044A (en) * | 1995-01-05 | 1995-11-21 | Westinghouse Electric Corporation | Transmission line power flow controller with unequal advancement and retardation of transmission angle |
US5610501A (en) * | 1995-02-01 | 1997-03-11 | Westinghouse Electric Corporation | Dynamic power and voltage regulator for an ac transmission line |
US5642007A (en) * | 1994-12-30 | 1997-06-24 | Westinghouse Electric Corporation | Series compensator inserting real and reactive impedance into electric power system for damping power oscillations |
US5646511A (en) * | 1995-05-29 | 1997-07-08 | Mitsubishi Denki Kabushiki Kaisha | Power system compensator apparatus and power converter apparatus |
US5754035A (en) * | 1997-01-14 | 1998-05-19 | Westinghouse Electric Corporation | Apparatus and method for controlling flow of power in a transmission line including stable reversal of power flow |
US5793136A (en) * | 1996-06-05 | 1998-08-11 | Redzic; Sabid | Differential motor/generator apparatus |
US5808452A (en) * | 1997-09-15 | 1998-09-15 | Gyugyi; Laszlo | Power flow controller with dc-to-dc converter linking shunt and series connected inverters |
US5814975A (en) * | 1995-06-05 | 1998-09-29 | Westinghouse Electric Corporation | Inverter controlled series compensator |
US5942880A (en) * | 1998-01-20 | 1999-08-24 | Mitsubishi Denki Kabushiki Kaisha | Compensation control device for a power system |
US6144191A (en) * | 2000-02-18 | 2000-11-07 | Utility Systems Technologies, Inc. | Voltage regulator |
US20030202367A1 (en) * | 2001-03-22 | 2003-10-30 | Dejan Schreiber | Power converter circuit arrangement for generators with dynamically variable power output |
US6737757B1 (en) * | 1999-06-04 | 2004-05-18 | Bonus Energy A/S | Wind power plant and method for operating it |
US6867522B1 (en) * | 2002-07-04 | 2005-03-15 | Robert Bosch Gmbh | Asynchronous machine |
US20050237678A1 (en) * | 2003-04-08 | 2005-10-27 | Reijo Virtanen | Configuration and method for protecting converter means |
US20060131960A1 (en) * | 2004-02-12 | 2006-06-22 | Mitsubishi Denki Kabushiki Kaisha | Power converter |
US20060163881A1 (en) * | 2002-07-17 | 2006-07-27 | Andreas Bucker | Method for operating a wind power plant and method for operating it |
US20060192390A1 (en) * | 2003-07-15 | 2006-08-31 | Javier Juanarena Saragueta | Control and protection of a doubly-fed induction generator system |
US20060214428A1 (en) * | 2003-06-16 | 2006-09-28 | Repower Systems Ag | Wind farm |
US20060238929A1 (en) * | 2003-02-07 | 2006-10-26 | Nielsen John G | Method for controlling a power-grid connected wind turbine generator during grid faults and apparatus for implementing said method |
US20070024059A1 (en) * | 2005-07-29 | 2007-02-01 | General Electric Company | System and method for power control in wind turbines |
US20070052394A1 (en) * | 2004-08-27 | 2007-03-08 | Seg Schaltan Lagen-Elektronik-Gerate Gmbh & Co. Kg | Power control of an induction machine |
US20070278797A1 (en) * | 2006-05-31 | 2007-12-06 | Flannery Patrick S | Power conditioning architecture for a wind turbine |
US20080150285A1 (en) * | 2006-12-22 | 2008-06-26 | Wind To Power System, S.L. | Doubly-controlled asynchronous generator |
US20080203978A1 (en) * | 2007-02-14 | 2008-08-28 | Semikron Elektronik Gmbh & Co. Kg | Frequency converter for a double-fed asynchronous generator with variable power output and method for its operation |
US7525824B2 (en) * | 2005-03-30 | 2009-04-28 | Alstom Technology Ltd | Method to control a frequency converter |
Family Cites Families (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE19833551A1 (en) * | 1998-07-24 | 2000-01-27 | Siemens Ag | Current supply system with DC link converter e.g. for locomotives and other rail-borne vehicles |
DE10105982A1 (en) * | 2001-02-09 | 2002-10-02 | Siemens Ag | Process for evaluating a measured value and associated circuit arrangement |
ES2245608B1 (en) * | 2004-06-30 | 2007-03-01 | Gamesa Eolica S.A. | PROCEDURE AND DEVICE TO AVOID THE DISCONNECTION OF A NETWORK ELECTRICAL POWER GENERATION PARK. |
GB2423650A (en) * | 2005-02-24 | 2006-08-30 | Alstom | Power converters |
-
2006
- 2006-12-28 EP EP06841773A patent/EP2128440A4/en not_active Withdrawn
- 2006-12-28 WO PCT/ES2006/000721 patent/WO2008081049A1/en active Application Filing
-
2007
- 2007-03-09 US US11/716,438 patent/US7652387B2/en not_active Expired - Fee Related
-
2009
- 2009-12-09 US US12/634,454 patent/US20100084865A1/en not_active Abandoned
Patent Citations (53)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2292171A (en) * | 1939-08-11 | 1942-08-04 | Gen Electric | Electric valve operated motor |
US2585392A (en) * | 1948-03-19 | 1952-02-12 | Jeumont Forges Const Elec | Monopolyphase frequency converter group |
US2859005A (en) * | 1952-11-21 | 1958-11-04 | Bendix Aviat Corp | Monitoring system for aircraft auto pilots |
US2916632A (en) * | 1956-05-05 | 1959-12-08 | Asea Ab | Means for controlling the position of a radiating body |
US3048771A (en) * | 1957-04-25 | 1962-08-07 | Standard Electrical Products C | Regulator |
US3211981A (en) * | 1957-04-25 | 1965-10-12 | Staco Inc | Motor control system with direct current braking |
US3469134A (en) * | 1965-07-31 | 1969-09-23 | Lloyd Dynamowerke Gmbh | Electrical machines |
US3591844A (en) * | 1967-09-26 | 1971-07-06 | Licentia Gmbh | Electrical apparatus for rotating a turbogenerator shaft |
US4341989A (en) * | 1979-03-08 | 1982-07-27 | Elmekano I Lulea Ab | Device for phase compensation and excitation of an asynchronous machine operating as a generator |
US4761602A (en) * | 1985-01-22 | 1988-08-02 | Gregory Leibovich | Compound short-circuit induction machine and method of its control |
US4651265A (en) * | 1985-07-29 | 1987-03-17 | Westinghouse Electric Corp. | Active power conditioner system |
US5083039A (en) * | 1991-02-01 | 1992-01-21 | U.S. Windpower, Inc. | Variable speed wind turbine |
US5083039B1 (en) * | 1991-02-01 | 1999-11-16 | Zond Energy Systems Inc | Variable speed wind turbine |
US5166597A (en) * | 1991-08-08 | 1992-11-24 | Electric Power Research Institute | Phase-shifting transformer system |
US5198746A (en) * | 1991-09-16 | 1993-03-30 | Westinghouse Electric Corp. | Transmission line dynamic impedance compensation system |
US5309346A (en) * | 1991-09-16 | 1994-05-03 | Westinghouse Electric Corp. | Transmission line fault current dynamic inverter control |
US5343139A (en) * | 1992-01-31 | 1994-08-30 | Westinghouse Electric Corporation | Generalized fast, power flow controller |
US5329222A (en) * | 1992-11-30 | 1994-07-12 | Westinghouse Electric Corporation | Apparatus and method for dynamic voltage restoration of utility distribution networks |
US5355295A (en) * | 1993-08-19 | 1994-10-11 | Westinghouse Electric Corporation | Series-parallel active power line conditioner utilizing temporary link energy boosting for enhanced peak voltage regulation capability |
US5642007A (en) * | 1994-12-30 | 1997-06-24 | Westinghouse Electric Corporation | Series compensator inserting real and reactive impedance into electric power system for damping power oscillations |
US5469044A (en) * | 1995-01-05 | 1995-11-21 | Westinghouse Electric Corporation | Transmission line power flow controller with unequal advancement and retardation of transmission angle |
US5610501A (en) * | 1995-02-01 | 1997-03-11 | Westinghouse Electric Corporation | Dynamic power and voltage regulator for an ac transmission line |
US5646511A (en) * | 1995-05-29 | 1997-07-08 | Mitsubishi Denki Kabushiki Kaisha | Power system compensator apparatus and power converter apparatus |
US5814975A (en) * | 1995-06-05 | 1998-09-29 | Westinghouse Electric Corporation | Inverter controlled series compensator |
US5793136A (en) * | 1996-06-05 | 1998-08-11 | Redzic; Sabid | Differential motor/generator apparatus |
US5754035A (en) * | 1997-01-14 | 1998-05-19 | Westinghouse Electric Corporation | Apparatus and method for controlling flow of power in a transmission line including stable reversal of power flow |
US5808452A (en) * | 1997-09-15 | 1998-09-15 | Gyugyi; Laszlo | Power flow controller with dc-to-dc converter linking shunt and series connected inverters |
US5942880A (en) * | 1998-01-20 | 1999-08-24 | Mitsubishi Denki Kabushiki Kaisha | Compensation control device for a power system |
US6737757B1 (en) * | 1999-06-04 | 2004-05-18 | Bonus Energy A/S | Wind power plant and method for operating it |
US6144191A (en) * | 2000-02-18 | 2000-11-07 | Utility Systems Technologies, Inc. | Voltage regulator |
US20030202367A1 (en) * | 2001-03-22 | 2003-10-30 | Dejan Schreiber | Power converter circuit arrangement for generators with dynamically variable power output |
US6867522B1 (en) * | 2002-07-04 | 2005-03-15 | Robert Bosch Gmbh | Asynchronous machine |
US20080093854A1 (en) * | 2002-07-17 | 2008-04-24 | Andreas Bucker | Method for Operating a Wind Power Plant and Method for Operating It |
US7321221B2 (en) * | 2002-07-17 | 2008-01-22 | General Electric Company | Method for operating a wind power plant and method for operating it |
US20060163881A1 (en) * | 2002-07-17 | 2006-07-27 | Andreas Bucker | Method for operating a wind power plant and method for operating it |
US7471007B2 (en) * | 2002-07-17 | 2008-12-30 | General Electric Company | Method for operating a wind power plant and method for operating it |
US7332827B2 (en) * | 2003-02-07 | 2008-02-19 | Vestas Wind Systems A/S | Method for controlling a power-grid connected wind turbine generator during grid faults and apparatus for implementing said method |
US20060238929A1 (en) * | 2003-02-07 | 2006-10-26 | Nielsen John G | Method for controlling a power-grid connected wind turbine generator during grid faults and apparatus for implementing said method |
US7164562B2 (en) * | 2003-04-08 | 2007-01-16 | Abb Oy | Configuration and method for protecting converter means |
US20050237678A1 (en) * | 2003-04-08 | 2005-10-27 | Reijo Virtanen | Configuration and method for protecting converter means |
US20060214428A1 (en) * | 2003-06-16 | 2006-09-28 | Repower Systems Ag | Wind farm |
US20060192390A1 (en) * | 2003-07-15 | 2006-08-31 | Javier Juanarena Saragueta | Control and protection of a doubly-fed induction generator system |
US7518256B2 (en) * | 2003-07-15 | 2009-04-14 | Gamesa Innovation & Technology, S.L. | Control and protection of a doubly-fed induction generator system |
US20060131960A1 (en) * | 2004-02-12 | 2006-06-22 | Mitsubishi Denki Kabushiki Kaisha | Power converter |
US7365451B2 (en) * | 2004-02-12 | 2008-04-29 | Mitsubishi Denki Kabushiki Kaisha | Power converter |
US20070052394A1 (en) * | 2004-08-27 | 2007-03-08 | Seg Schaltan Lagen-Elektronik-Gerate Gmbh & Co. Kg | Power control of an induction machine |
US7423406B2 (en) * | 2004-08-27 | 2008-09-09 | Woodward Seg Gmbh & Co Kg | Power control of an induction machine |
US7525824B2 (en) * | 2005-03-30 | 2009-04-28 | Alstom Technology Ltd | Method to control a frequency converter |
US7239036B2 (en) * | 2005-07-29 | 2007-07-03 | General Electric Company | System and method for power control in wind turbines |
US20070024059A1 (en) * | 2005-07-29 | 2007-02-01 | General Electric Company | System and method for power control in wind turbines |
US20070278797A1 (en) * | 2006-05-31 | 2007-12-06 | Flannery Patrick S | Power conditioning architecture for a wind turbine |
US20080150285A1 (en) * | 2006-12-22 | 2008-06-26 | Wind To Power System, S.L. | Doubly-controlled asynchronous generator |
US20080203978A1 (en) * | 2007-02-14 | 2008-08-28 | Semikron Elektronik Gmbh & Co. Kg | Frequency converter for a double-fed asynchronous generator with variable power output and method for its operation |
Cited By (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20110018270A1 (en) * | 2006-12-22 | 2011-01-27 | Wind To Power System, S.L. | Doubly-controlled asynchronous generator |
US20110109085A1 (en) * | 2009-11-10 | 2011-05-12 | Nelson Robert J | Power Oscillation Damping Employing a Full or Partial Conversion Wind Turbine |
US9478987B2 (en) * | 2009-11-10 | 2016-10-25 | Siemens Aktiengesellschaft | Power oscillation damping employing a full or partial conversion wind turbine |
CN106202616A (en) * | 2016-06-23 | 2016-12-07 | 广东电网有限责任公司电力科学研究院 | Kinetic characteristic analogy method under a kind of transformer short circuit fault and system |
RU2660187C1 (en) * | 2017-04-04 | 2018-07-05 | федеральное государственное бюджетное образовательное учреждение высшего образования "Ульяновский государственный технический университет" | Four-quadrant low-voltage ac drive and method of its control |
US20200144826A1 (en) * | 2018-11-06 | 2020-05-07 | General Electric Company | System and Method for Wind Power Generation and Transmission in Electrical Power Systems |
US10826297B2 (en) * | 2018-11-06 | 2020-11-03 | General Electric Company | System and method for wind power generation and transmission in electrical power systems |
Also Published As
Publication number | Publication date |
---|---|
WO2008081049A1 (en) | 2008-07-10 |
US7652387B2 (en) | 2010-01-26 |
EP2128440A1 (en) | 2009-12-02 |
EP2128440A4 (en) | 2012-03-14 |
US20080157530A1 (en) | 2008-07-03 |
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