CN109995068B - Fault ride-through control apparatus and method - Google Patents
Fault ride-through control apparatus and method Download PDFInfo
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- CN109995068B CN109995068B CN201711479338.XA CN201711479338A CN109995068B CN 109995068 B CN109995068 B CN 109995068B CN 201711479338 A CN201711479338 A CN 201711479338A CN 109995068 B CN109995068 B CN 109995068B
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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
- H02J3/24—Arrangements for preventing or reducing oscillations of power in networks
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- H02J3/386—
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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
- H02J3/46—Controlling of the sharing of output between the generators, converters, or transformers
- H02J3/50—Controlling the sharing of the out-of-phase component
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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
- H02P9/006—Means for protecting the generator by using control
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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
- H02P9/14—Arrangements for controlling electric generators for the purpose of obtaining a desired output by variation of field
- H02P9/26—Arrangements for controlling electric generators for the purpose of obtaining a desired output by variation of field using discharge tubes or semiconductor devices
- H02P9/30—Arrangements for controlling electric generators for the purpose of obtaining a desired output by variation of field using discharge tubes or semiconductor devices using semiconductor devices
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- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E10/00—Energy generation through renewable energy sources
- Y02E10/70—Wind energy
- Y02E10/76—Power conversion electric or electronic aspects
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Abstract
The embodiment of the invention discloses a fault ride-through control device and a fault ride-through control method. The method comprises the steps that a first feedback adjusting module outputs a Pulse Width Modulation (PWM) signal for driving an Insulated Gate Bipolar Transistor (IGBT) in a machine side boost circuit of a converter according to a boost current measured value and an initial boost current given value; the control module judges whether the power grid voltage meets a preset dropping condition or not according to the three-phase voltage signal of the power grid, and controls a circuit between the second feedback regulation module and the first feedback regulation module to be connected when the power grid voltage meets the preset dropping condition; the second feedback adjusting module adjusts the initial boost current set value according to an error signal between the measured value of the direct current bus voltage and the direct current bus voltage set value, so that the first feedback adjusting module outputs an updated PWM signal. By adopting the technical scheme in the embodiment of the invention, the long-time heavy-load operation of the braking unit can be avoided, and the failure rate of the braking unit is reduced.
Description
Technical Field
The invention relates to the technical field of wind power generation, in particular to a fault ride-through control device and method.
Background
The generated energy of the wind generating set needs to be merged into a power grid through a converter after being rectified. When the power grid is unstable in operation, for example, a power grid fault such as a rise or a drop of the power grid voltage occurs, the energy incorporated into the power grid is reduced, the voltage at the outlet of the generator is rapidly increased due to the reduction of the energy incorporated into the power grid, and further, the rectified voltage is increased, however, the output power of the wind generating set is temporarily kept unchanged, and the imbalance of the input and output energy of the converter causes the voltage of the direct current bus to be rapidly increased, which affects the safe operation of the wind generating set.
In order to ensure the safe operation of the wind generating set, the method in the prior art is to arrange a brake unit in a converter, and when the voltage of a power grid drops, the brake unit is started to control an IGBT module to work so as to drive a brake resistor to release redundant energy on a direct-current bus and restore the voltage of the direct-current bus to a normal voltage range.
However, the inventor of the present application finds that, because the operating state of the power grid is not controllable, the IGBT module and the brake resistor in the brake unit may need to be heavily operated for a long time, and the failure rate of the brake unit may be increased due to the long-time heavy operation.
Disclosure of Invention
The embodiment of the invention provides a fault ride-through control device and method, which can avoid long-time heavy-load operation of a brake unit and reduce the fault rate of the brake unit.
In a first aspect, an embodiment of the present invention provides a fault ride-through control apparatus, including: the device comprises a control module, a first feedback regulation module and a second feedback regulation module; wherein the content of the first and second substances,
the first feedback adjusting module outputs a Pulse Width Modulation (PWM) signal for driving an Insulated Gate Bipolar Transistor (IGBT) in a machine side boost circuit of the converter according to a boost current measured value and an initial boost current given value;
the control module judges whether the power grid voltage meets a preset dropping condition or not according to the three-phase voltage signal of the power grid, and controls a circuit between the second feedback regulation module and the first feedback regulation module to be connected when the power grid voltage meets the preset dropping condition;
the second feedback regulation module also regulates the initial boost current given value according to an error signal between the direct current bus voltage measured value and the direct current bus voltage given value, so that the first feedback regulation module outputs an updated PWM signal, and the direct current bus voltage approaches to the direct current bus voltage given value in the fault ride-through process.
In some embodiments of the first aspect, the control module comprises a first arithmetic unit, a first judging unit, and a first switching unit; the first switch unit is arranged on a line between the first feedback regulation module and the second feedback regulation module; the first operation unit is used for performing effective value operation on three phase voltages and three line voltages of the power grid by using three-phase voltage signals of the power grid to obtain effective values of all the voltages; and the first judging unit is used for respectively judging whether the effective value of each voltage is lower than the corresponding drop threshold voltage, and outputting a first control signal to the first switching unit to switch on a line between the second feedback regulating module and the first feedback regulating module when the effective value of any one voltage is lower than the corresponding drop threshold voltage.
In some embodiments of the first aspect, the control module further includes a second determining unit, configured to determine whether all of the effective values of all of the phase voltages and the line voltages reach the corresponding recovery threshold voltages, and output a second control signal to the first switching unit to disconnect the second feedback regulating module from the first feedback regulating module when all of the effective values of all of the phase voltages and the line voltages reach the corresponding recovery threshold voltages.
In some embodiments of the first aspect, the control module further comprises a second switching unit and a speed limiter; the second switch unit is arranged on a line between a generator of the wind generating set and the first feedback adjusting module; the second judgment unit is also used for outputting a third control signal to the second switching unit within a preset time period after all the phase voltages and the line voltages reach the corresponding recovery threshold voltages, so that the speed limiter is connected in series with a line between the generator and the first feedback regulation module; and after a predetermined period of time, outputting a fourth control signal to the second switching unit to cut the speed limiter off from a line between the generator and the first feedback regulation block.
In some embodiments of the first aspect, the initial boost current setpoint is a ratio between an output power of the wind park and a machine side rectified voltage; the control module further comprises a third judging unit for judging whether the machine side rectified voltage or the direct current bus voltage reaches the starting voltage of the braking unit of the converter, and outputting a control signal for starting the braking unit when the machine side rectified voltage or the direct current bus voltage reaches the starting voltage of the braking unit.
In some embodiments of the first aspect, the fault ride-through control further comprises a third feedback regulation module, a fourth feedback regulation module, and a phase-locked loop; the third feedback adjusting module outputs an active current given value of the power grid according to an error signal between a direct current bus voltage measured value and a direct current bus voltage given value; the fourth feedback adjusting module outputs a PWM signal for driving an IGBT in the converter according to an active current set value of the power grid, an external power grid reactive current set value, a phase value output by the phase-locked loop and a three-phase current measured value of the power grid; the control module also obtains a positive sequence component of the power grid voltage according to the three-phase voltage signal of the power grid, calculates a given reactive current value required to be sent by the converter in the fault ride-through process based on the positive sequence component of the power grid voltage, and updates the given reactive current value of the external power grid by using the given reactive current value required to be sent by the converter when the power grid voltage meets a preset dropping condition; the fourth feedback adjusting module also outputs an updated PWM signal according to an active current set value of the power grid, a reactive current set value required to be sent by the converter, a phase value output by the phase-locked loop and a three-phase current measured value of the power grid, so that reactive power output by the converter in the fault ride-through process meets the reactive demand of the power grid.
In some embodiments of the first aspect, the control module further comprises a second arithmetic unit and a third switching unit; the second operation unit is used for obtaining a positive sequence component of the voltage of the power grid according to the three-phase voltage signal of the power grid and calculating a reactive current given value required to be sent by the converter in the fault ride-through process according to the positive sequence component of the voltage of the power grid; the third switching unit is arranged on a line between the second operation unit and the fourth feedback regulation module; the first judging unit is also used for outputting a fifth control signal to the third switching unit when the effective value of any voltage is lower than the corresponding drop threshold voltage, switching on a line between the second operation unit and the fourth feedback regulation module, suspending the given value of the reactive current given value of the external power grid, and taking the reactive current given value required to be sent by the converter as a new reactive current given value.
In some embodiments of the first aspect, the second determining unit is further configured to output a sixth control signal to the third switching unit when the effective values of all the phase voltages and the line voltages all reach the corresponding recovery threshold voltages, disconnect the second feedback regulation module from the first feedback regulation module, and recover the given value of the reactive current of the external power grid.
In some embodiments of the first aspect, the control module further comprises a limiter, the limiter being disposed on a line between the third adjustment module and the fourth adjustment module.
In a second aspect, an embodiment of the present invention provides a fault ride-through control method, including:
outputting a PWM signal for driving an IGBT in a machine side boost circuit of the converter by a first feedback regulation module according to a boost current measured value and an initial boost current given value;
when the power grid voltage meets a preset dropping condition, controlling a circuit between the second feedback regulation module and the first feedback regulation module to be connected;
and the second feedback regulation module also regulates the initial boost current given value according to an error signal between the direct current bus voltage measured value and the direct current bus voltage given value, so that the first feedback regulation module outputs an updated PWM signal to enable the direct current bus voltage to approach the direct current bus voltage given value in the fault ride-through process.
In some embodiments of the second aspect, determining whether the grid voltage meets the preset droop condition according to the three-phase voltage signal of the grid includes: carrying out effective value operation on three phase voltages and three line voltages of the power grid by using three-phase voltage signals of the power grid to obtain effective values of all the voltages; and respectively judging whether the effective value of each voltage is lower than the corresponding drop threshold voltage, and determining that the wind generating set is in a fault ride-through working condition when the effective value of any voltage is lower than the corresponding drop threshold voltage.
In some embodiments of the second aspect, the fault-ride-through control method further comprises: and judging whether the effective values of all the phase voltages and the line voltages all reach the corresponding recovery threshold voltages, and disconnecting the second feedback regulation module from the first feedback regulation module when the effective values of all the phase voltages and the line voltages all reach the corresponding recovery threshold voltages.
In some embodiments of the second aspect, the fault-ride-through control method further comprises: in a preset time period after all phase voltages and line voltages reach corresponding recovery threshold voltages, enabling the speed limiter to be connected in series with a line between the generator and the first feedback regulation module; and after a predetermined period of time, cutting the speed limiter off the line between the generator and the first feedback regulation module.
In some embodiments of the second aspect, the fault ride-through control method, the initial boost current setpoint is a ratio between an output power of the wind park and a machine side rectified voltage; the fault ride-through control method further comprises the following steps: and judging whether the machine side rectified voltage reaches the starting voltage of the braking unit of the converter, and outputting a control signal for starting the braking unit when the machine side rectified voltage reaches the starting voltage of the braking unit.
In some embodiments of the second aspect, the fault-ride-through control method further comprises: outputting an active current given value of the power grid by a third feedback regulation module according to an error signal between a direct current bus voltage measured value and a direct current bus voltage given value; a fourth feedback adjusting module outputs a PWM signal for driving an IGBT in a converter according to an active current set value of a power grid, an external power grid reactive current set value, a phase value output by a phase-locked loop and a three-phase current measured value of the power grid; obtaining a positive sequence component of the voltage of the power grid according to a three-phase voltage signal of the power grid, calculating a given reactive current value required to be sent by the converter in the fault ride-through process based on the positive sequence component of the voltage of the power grid, suspending the given reactive current value of an external power grid when the voltage of the power grid meets a preset dropping condition, and taking the given reactive current value required to be sent by the converter as a new given reactive current value; and the fourth feedback regulation module outputs an updated PWM signal according to an active current set value of the power grid, a reactive current set value required to be sent by the converter, a phase value output by the phase-locked loop and a three-phase current measured value of the power grid, so that the reactive power output by the converter in the fault ride-through process meets the reactive requirement of the power grid.
In some embodiments of the second aspect, the fault-ride-through control method further comprises: and judging whether the effective values of all the phase voltages and the line voltages all reach the corresponding recovery threshold voltages, and stopping giving the reactive current given values required to be sent by the converter when the effective values of all the phase voltages and the line voltages all reach the corresponding recovery threshold voltages, and recovering the given reactive current given values of the external power grid.
According to the embodiment of the invention, when the grid voltage fails, namely when the grid voltage meets the preset dropping condition, a line between the second feedback regulation module and the first feedback regulation module can be connected, and the second feedback regulation module utilizes the measured value U of the DC bus voltagedcGiven value U of sum DC bus voltagedcError signal between to initial boost current set value IboostAdjusting and setting the adjusted boost current to a given value IboostInputting the measured value to the first feedback regulation module to make the first feedback regulation module capable of measuring the measured value I according to the boost currentboostAnd regulated boost current set value IboostAnd outputting the updated PWM signal according to the difference value between the two.
Due to the regulated boost current set value IboostAnd the updated PWM signal is used for driving the IGBT in the machine side boost circuit of the converter to work, so that the voltage of the direct current bus in the fault ride-through process approaches to the given value of the voltage of the direct current bus.
Compared with the prior art which needs the IGBT module and the brake resistor in the brake unit to operate for a long time with heavy load, the second feedback regulation module in the embodiment of the invention can regulate the given value I of boost currentboostFrom the viewpoint of adjusting the dc bus voltage during the fault ride-through, those skilled in the art may use the fault ride-through control device in the embodiment of the present invention alone, or in combination with the brake unitThe fault rate of the brake unit is reduced by combining the brake unit and the aging speed of the brake unit is reduced, and the safety of grid-connected operation of the wind generating set is ensured.
Drawings
The present invention will be better understood from the following description of specific embodiments thereof taken in conjunction with the accompanying drawings, in which like or similar reference characters designate like or similar features.
Fig. 1 is a schematic diagram of a grid-connected structure of a wind generating set according to an embodiment of the present invention;
fig. 2 is a schematic structural diagram of a fault ride-through control device according to a first embodiment of the present invention;
fig. 3 is a schematic structural diagram of a fault ride-through control device according to a second embodiment of the present invention;
fig. 4 is a schematic structural diagram of a fault ride-through control device according to a third embodiment of the present invention;
fig. 5 is a schematic structural diagram of a fault ride-through control device according to a fourth embodiment of the present invention;
fig. 6 is a schematic structural diagram of a fault-ride-through control device according to a fifth embodiment of the present invention;
fig. 7 is a schematic structural diagram of a fault ride-through control device according to a sixth embodiment of the present invention;
fig. 8 is a schematic flowchart of a fault-ride-through control method according to an embodiment of the present invention;
fig. 9 is a flowchart illustrating a fault-ride-through control method according to another embodiment of the present invention.
Description of reference numerals:
101-a rectifier; 102-boost circuit; 103-a current transformer; 201-a control module;
2011-a first arithmetic unit; 2012-a first judging unit; 2013 a first switch unit;
2014-a second switching unit; 2015-speed limiter; 2016 — a second arithmetic unit;
2017-a third switching unit; 202-a first feedback adjustment module;
203-a second feedback adjustment module; 501-a third feedback regulation module;
502-a fourth feedback regulation module; 503-phase locked loop.
Detailed Description
Features of various aspects of embodiments of the invention and exemplary embodiments will be described in detail below. In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of embodiments of the invention.
The embodiment of the invention provides a fault ride-through control device and a fault ride-through control method. By adopting the method in the embodiment of the invention, the brake unit of the converter can be prevented from long-time heavy load operation, so that the fault rate of the brake unit is reduced, and when the power grid fails, such as serious abnormal conditions of unbalanced drop or rise, voltage waveform distortion and the like, the grid-connected current of the wind generating set can be ensured to be completely controllable, so that the system has good grid-connected friendliness.
Fig. 1 is a schematic diagram of a grid-connected structure of a wind turbine generator system according to an embodiment of the present invention. As shown in fig. 1, a rectifier 101, a boost circuit 102 and a converter 103 are sequentially arranged between the wind generating set and the power grid.
The rectifier 101 is used for rectifying three-phase alternating current generated by the wind generating set, then direct current output by the rectifier 101 is input to the converter 103 by the boost circuit 102, and then the direct current input by the boost circuit 102 is converted into three-phase alternating current again by the converter 103 and incorporated into a power grid. Among them, the IGBT104 module in the converter 103 is also referred to as a power module for specifically performing an operation of converting a direct current into a three-phase alternating current. The generator of the wind power plant shown in fig. 1 is a permanent magnet synchronous generator PMSG.
Fig. 2 is a schematic structural diagram of a fault-ride-through control device according to a first embodiment of the present invention. The fault ride-through control apparatus shown in fig. 2 includes a control module 201, a first feedback regulation module 202, and a second feedback regulation module 203.
Wherein, the first feedback adjusting module 202 measures the value I according to the boost currentboostAnd initial boost current set value IboostOutputting a pulse width modulation PWM signal for driving the IGBTs in the machine side boost circuit of the converter。
The control module 201 is based on the three-phase voltage signal (U) of the grida，Ub，Uc) And judging whether the power grid voltage meets a preset dropping condition, and controlling a circuit between the second feedback regulation module 203 and the first feedback regulation module 202 to be connected when the power grid voltage meets the preset dropping condition.
The second feedback adjustment module 203 further measures the dc bus voltage U according to the measured valuedcGiven value U of sum DC bus voltagedcError signal between, given value of initial boost current IboostThe adjustment is performed to make the first feedback adjustment module 202 output the updated PWM signal, so that the dc bus voltage approaches the dc bus voltage set value in the fault ride-through process.
According to an embodiment of the present invention, the first feedback adjustment module 202 may be continuously activated, and the first feedback adjustment module 202 is utilized to adjust the measured value I of the boost current according to the measured value I of the boost currentboostAnd initial boost current set value IboostAnd outputting a PWM signal for driving an IGBT in the machine side boost circuit of the converter according to the difference between the two signals, and continuously finely adjusting boost current to stabilize the input current of the converter.
When the grid voltage fails, that is, when the grid voltage meets the preset droop condition, the line between the second feedback regulation module 203 and the first feedback regulation module 202 may be connected, and the second feedback regulation module 203 uses the measured value U of the dc bus voltagedcGiven value U of sum DC bus voltagedcError signal between to initial boost current set value IboostAdjusting and setting the adjusted boost current to a given value IboostInput to the first feedback regulation module 202, so that the first feedback regulation module 202 can regulate the measured value I of the boost current according to the measured value I of the boost currentboostAnd regulated boost current set value IboostAnd outputting the updated PWM signal according to the difference value between the two.
Due to the regulated boost current set value IboostThe PWM signal is related to the direct current bus voltage in the fault ride-through process, can reflect the power grid state in the fault ride-through process, and is used for driving the transformer by using the updated PWM signalThe IGBT in the machine side boost circuit of the current transformer works, so that the direct current bus voltage approaches to the given value of the direct current bus voltage in the fault ride-through process.
Compared with the prior art which needs the IGBT module and the brake resistor in the brake unit to operate under heavy load for a long time, the second feedback regulation module 203 in the embodiment of the invention can regulate the given value I of boost currentboostFrom the angle, the direct-current bus voltage in the fault ride-through process is adjusted, and a person skilled in the art can use the fault ride-through control device in the embodiment of the invention alone or in combination with the brake unit to reduce the fault rate of the brake unit, so as to slow down the aging rate of the brake unit and ensure the safety of grid-connected operation of the wind generating set.
Fig. 3 is a schematic structural diagram of a fault-ride-through control device according to a second embodiment of the present invention. Fig. 3 is different from fig. 2 in that the control module 201 in fig. 2 includes a first arithmetic unit 2011, a first determination unit 2012 and a first switch unit 2013.
The first switching unit 2013 is arranged on a line between the first feedback regulation module 202 and the second feedback regulation module 203;
the first arithmetic unit 2011 is used to utilize the three-phase voltage signal (U) of the grida，Ub，Uc) Carrying out effective value operation on three phase voltages and three line voltages of a power grid to obtain effective values of all the voltages;
the first determining unit 2012 is configured to determine whether the effective value of each voltage is lower than the corresponding drop threshold voltage, and output a first control signal to the first switching unit 2013 to connect a line between the second feedback regulating module 203 and the first feedback regulating module 202 when the effective value of any one voltage is lower than the corresponding drop threshold voltage.
As shown in fig. 3, the first switch unit 2013 may be implemented in a multi-contact switch, where a stationary contact of the multi-contact switch is connected to a movable contact with a flag of 0 when the power grid is in normal operation, and the stationary contact of the multi-contact switch is connected to a movable contact with a flag of 1 when the power grid is in fault, so as to switch on the second feedback regulation module203 and the first feedback regulating module 202 to utilize the measured value U of the dc bus voltagedcGiven value U of sum DC bus voltagedcError signal between to initial boost current set value IboostAdjusting and setting the adjusted boost current to a given value IboostInput to the first feedback regulation module 202, so that the first feedback regulation module 202 can regulate the measured value I of the boost current according to the measured value I of the boost currentboostAnd regulated boost current set value IboostAnd outputting the updated PWM signal according to the difference value between the two.
According to an embodiment of the present invention, the control module 201 further includes a second determining unit (not shown in the figure) for determining whether all the effective values of all the phase voltages and the line voltages reach the corresponding recovery threshold voltages, and outputting a second control signal to the first switching unit 2013 to disconnect the connection between the second feedback adjusting module 203 and the first feedback adjusting module 202 when all the effective values of all the phase voltages and the line voltages reach the corresponding recovery threshold voltages.
The dropping threshold voltage is used for representing the dropping depth of the power grid voltage, and can be equal to or smaller than the recovery threshold voltage. The recovery threshold voltage is used to indicate that the grid voltage has recovered to a normal operating voltage.
The identification of the grid drop can be judged by using the effective value of the grid voltage, for example, when the voltage is lower than the lower limit value of the normal working voltage by 0.9pu, the grid drop is considered to occur. However, the lower limit value may be appropriately set lower in order to improve the interference resistance.
In one example, effective values may be calculated for three phase voltages and three line voltages, respectively, the six voltages are compared with a low voltage threshold value in turn, and if at least one is lower than the threshold value, it is concluded that a grid low voltage occurs.
Fig. 4 is a schematic structural diagram of a fault-ride-through control device according to a third embodiment of the present invention. Fig. 4 differs from fig. 3 in that the control module 201 in fig. 4 includes a second switching unit 2014 and a speed limiter 2015.
Wherein, the second switching unit 2014 is arranged on a line between the generator of the wind generating set and the first feedback adjusting module 202.
In the voltage recovery process, in order to prevent the converter from being impacted by sudden grid-connected power, the second judging unit is further configured to output a third control signal to the second switching unit 2014 within a predetermined time period after all phase voltages and line voltages reach corresponding recovery threshold voltages, so that the speed limiter 2015 is connected in series to a line between the generator and the first feedback regulating module 202; and after a predetermined period of time, outputting a fourth control signal to the second switching unit 2014, cutting the speed limiter 2015 from the line between the generator and the first feedback regulation module 202.
As shown in fig. 4, a specific implementation form of the second switch unit 2014 may be a multi-contact switch, in which a stationary contact is connected with a movable contact with a flag of (1-0) within a predetermined time period after all phase voltages and line voltages reach corresponding recovery threshold voltages, so that the speed limiter 2015 is connected in series to a line between the generator and the first feedback regulation module 202; when the stationary contacts in the multi-contact switch are connected with the movable contact with the flag being (0,1) after a predetermined period of time, the speed limiter 2015 is cut off from the line between the generator and the first feedback regulation block 202.
According to an embodiment of the invention, adding a speed limiting device "limiter 2015" after the boost current is given, can make the boost current given value IboostSlow recovery, boost current set value IboostApproximately proportional to the input power of the converter, i.e. the input power can be recovered slowly, then the grid side power is also gradually recovered. By adopting the control strategy, the strong impact of voltage recovery on the converter can be avoided, and the stability of grid-connected operation of the wind generating set is improved.
In one example, as shown in FIG. 4, the initial boost current is given by a value IboostCan be the output power P of the wind generating setelecSum machine side rectified voltage UrecThe ratio therebetween.
Due to the operating characteristics of the wind generating set, in the process of reducing boost current, the generator side rectifies the currentPress UrecAnd does not remain the same, but rather rises to some extent. If the machine side rectified voltage UrecWhen the output voltage is higher than the given value of the direct current bus, the boost circuit is not controlled, the input power of the converter is also not controlled, the voltage of the direct current bus is increased along with the increase of the rectified voltage, and the power balance algorithm is also failed.
The control module 201 further includes a third judging unit (not shown in the figure) for judging the machine-side rectified voltage UrecOr DC bus voltage UdcWhether the starting voltage of the braking unit of the converter is reached and the machine-side rectified voltage U is detectedrecOr DC bus voltage UdcWhen the starting voltage of the braking unit is reached, a control signal for starting the braking unit is output. The brake resistor in the brake unit starts to act, and finally the machine side rectified voltage U is enabledrecStabilized around the starting voltage. The method is characterized in that the braking unit is started only when the input power of the converter is extremely larger than the output power, and when the difference is smaller, the boost current is reduced enough to balance the power of the converter.
In addition, during voltage sags, standards dictate that the converter should be able to generate a certain reactive power to assist the grid restoration. Control of reactive power may be equivalent to control of reactive current. For example, the standards require that the reactive current response time be no greater than 75ms and the duration be no less than 550 ms.
Fig. 5 is a schematic structural diagram of a fault ride-through control device according to a fourth embodiment of the present invention. Fig. 5 differs from fig. 2 in that the fault-ride-through control device in fig. 5 further comprises a third feedback regulation module 501, a fourth feedback regulation module 502 and a phase-locked loop 503 for satisfying the reactive requirement specified by the standard.
The third feedback adjustment module 501 adjusts the dc bus voltage according to the measured value UdcGiven value U of sum DC bus voltagedcError signal between them, output electric network active current given value Id*。
The fourth feedback adjustment module 502 sets the value I according to the active current of the griddReactive current given value I of external power gridqOutput from phase-locked loop 503Phase value theta and actual three-phase current values (I) of the networka，Ib，Ic) Outputting a PWM signal for driving an IGBT in the converter;
the control module 201 also bases on the three-phase voltage signal (U) of the grida，Ub，Uc) To obtain the positive sequence component U of the network voltaged +And based on the positive sequence component U of the network voltaged +Calculating a given value I of reactive current required to be sent by a converter in the fault ride-through processqAnd when the grid voltage meets the preset dropping condition, utilizing the idle current set value I required to be sent by the converterqUpdating external power grid reactive current given value Iq*；
The fourth feedback regulation module 502 also sets the value I according to the active current of the griddReactive current set value I required to be sent by converterqPhase value theta output by phase-locked loop 503 and three-phase current measured value (I) of power grida，Ib，Ic) And outputting the updated PWM signal so that the reactive power output by the converter in the fault ride-through process meets the reactive power requirement of the power grid.
Wherein the phase locked loop 503 is capable of converting the three-phase voltage (U) of the grida，Ub，Uc) The abc static coordinate system is transformed to a dq synchronous rotating coordinate system, the q-axis component is eliminated through closed loop regulation in a phase lock, the rotating angle of the dq coordinate system at the moment is the real phase of the voltage of the power grid, and the method is very effective to a symmetrical power grid.
When the three-phase asymmetry occurs in the power grid, the fact that the three-phase voltage contains the positive sequence component and the negative sequence component is considered, so that the negative sequence component can be filtered by using a filter and then calculated, and meanwhile, the filter can be used for eliminating higher harmonics and then calculating the phase, so that the stability of the output phase is improved.
In order to improve the response speed and the tracking precision, a PID regulator can be adopted to control the reactive current and connect the grid current (I)a，Ib，Ic) And decoupling to obtain reactive current components. Given value of reactive current I required to be emitted by converterqAnd comparing the reactive current component obtained by decoupling with the reactive current component, and then entering a closed-loop regulator, wherein the PID regulator outputs a PWM signal for driving an IGBT in the converter and participates in the regulation of grid-connected current.
Specifically, the given value I of the minimum reactive current required by the power grid during fault ride-through can be calculated by using formula (1)qmin**：
Iqmin**＝1.5×(0.9-UT +)×IN(1)
Wherein, UT +For a per unit value of reactive current given, INIs the per unit value of the positive sequence component of the network side voltage, i.e. the positive sequence component U of the network voltaged +Per unit value of.
As shown in fig. 5, the control module 201 further includes a second operation unit 2016 and a third switching unit 2017.
Wherein the second arithmetic unit 2016 is configured to determine a three-phase voltage signal (U) from the power grida，Ub，Uc) Obtaining the positive sequence component U of the network voltaged +And according to the positive sequence component U of the network voltaged +Calculating a given value I of reactive current required to be sent by a converter in the fault ride-through processq**。
The third switching unit 2017 is disposed on a line between the second arithmetic unit 2016 and the fourth feedback adjustment module 502. The first determining unit 2012 is further configured to output a fifth control signal to the third switching unit 2017 when the effective value of any one of the voltages is lower than the corresponding droop threshold voltage, connect the line between the second computing unit 2016 and the fourth feedback adjusting module 502, and suspend the external grid reactive current given value IqSetting the current transformer and setting the idle current I to be generated by the current transformerqAs new reactive current setpoint.
As shown in fig. 5, the first switch unit 2013 may be implemented in a multi-contact switch, and when the power grid normally operates, a fixed contact in the multi-contact switch is connected to a movable contact with a flag bit of 0, so that the fourth feedback adjustment module 502 receives an external power grid reactive current given value IqA first step of; when the power grid is in failure, the multi-contact switch is in static contactThe point is connected with a movable contact with a flag bit flag of 1, and a circuit between the second operation unit 2016 and the fourth feedback regulation module 502 is connected to suspend the idle current given value I of the external power gridqSetting the current transformer and setting the idle current I to be generated by the current transformerqAs new reactive current setpoint.
According to the embodiment of the invention, the second judging unit is further configured to judge whether the effective values of all the phase voltages and the line voltages all reach the corresponding recovery threshold voltages, and when the effective values of all the phase voltages and the line voltages all reach the corresponding recovery threshold voltages, output a sixth control signal to the third switching unit 2017, disconnect the second feedback regulating module 203 from the first feedback regulating module 202, and recover the given I of the idle current given value of the external power gridq*。
According to an embodiment of the present invention, the control module 201 may further include a limiter (see the limiter in fig. 6), which is disposed on a line between the third regulation module and the fourth regulation module, and is used for limiting the active current setpoint I of the power grid output by the third regulation moduled*. When the energy on the direct current bus is excessive, the active current set value I of the power griddWill gradually become bigger, can set up the maximum set point I of active current at the amplitude limiterdmaxMaximum current that the converter can withstand to prevent the active current of the grid from setting a value IdToo large, resulting in overcurrent failure of the converter.
Fig. 6 is a schematic structural diagram of a fault-ride-through control device according to a fifth embodiment of the present invention, which is used to illustrate the fault-ride-through control device in the embodiment of the present invention, so as to facilitate understanding of technical solutions in the embodiment of the present invention.
As shown in FIG. 6, the first feedback adjustment module 202 is IboostRegulator, the second feedback regulation module 203 is UdcAuxiliary regulator, the third feedback regulation module 501 is UdcAuxiliary regulator, the fourth feedback regulation module 502 is IabcA regulator, an effective value calculator for using the three-phase voltage signal (U) of the power grida，Ub，Uc) To three phases of the gridThe effective value operation is carried out on the voltage and the three line voltages to obtain the effective value of each voltage, and the FUN function module is used for calculating the given value I of the reactive current required to be sent by the converterq**。
Wherein, IboostThe regulator is based on the measured value I of boost currentboostAnd initial boost current set value IboostOutputting a Pulse Width Modulation (PWM) signal for driving the IGBTs in the machine side boost circuit of the converter.
When the voltage of the power grid meets the preset dropping condition, UdcAuxiliary regulator and IboostThe lines between the regulators are connected so that IboostThe regulator is also based on the measured value U of the DC bus voltagedcGiven value U of sum DC bus voltagedcError signal between, given value of initial boost current IboostAnd adjusting and outputting the updated PWM signal so that the direct current bus voltage approaches to a direct current bus voltage given value in the fault ride-through process.
Fig. 7 is a schematic structural diagram of a fault ride-through control device according to a sixth embodiment of the present invention, which is used to show the fault ride-through control device after expanding the technical solution in the embodiment of the present invention. Fig. 7 differs from fig. 6 in that the rectifier in fig. 6 is a diode rectifier and the rectifier in fig. 7 is a fully controlled rectifier, i.e. a PWM converter containing IGBTs as the grid side, which controls the power absorbed from the generator by controlling the torque.
In the example of fig. 7, the torque regulator outputs a pulse width modulation PWM signal for driving the IGBTs in the machine side boost circuit of the converter, based on the measured torque value T and the initial torque set value T. When the voltage of the power grid meets the preset dropping condition, UdcThe circuit between the auxiliary regulator and the torque regulator is connected, so that the torque regulator is also based on the measured value U of the DC bus voltagedcGiven value U of sum DC bus voltagedcAnd adjusting the initial torque given value T by the error signal between the two, and outputting an updated PWM signal so as to enable the direct current bus voltage to approach the direct current bus voltage given value in the fault ride-through process.
Fig. 8 is a flowchart illustrating a fault-ride-through control method according to an embodiment of the present invention, where the fault-ride-through control method illustrated in fig. 8 includes steps 801 to 806.
In step 801, a first feedback adjustment module outputs a Pulse Width Modulation (PWM) signal for driving an IGBT in a machine-side boost circuit of the converter according to a boost current measured value and an initial boost current set value.
In step 802, whether the grid voltage meets a preset dropping condition is judged according to the three-phase voltage signal of the grid, and when the grid voltage meets the preset dropping condition, a circuit between the second feedback regulation module and the first feedback regulation module is controlled to be connected.
Specifically, judging whether the grid voltage meets the preset dropping condition according to the three-phase voltage signal of the grid may include: carrying out effective value operation on three phase voltages and three line voltages of the power grid by using three-phase voltage signals of the power grid to obtain effective values of all the voltages; and then respectively judging whether the effective value of each voltage is lower than the corresponding drop threshold voltage, and determining that the wind generating set is in a fault ride-through working condition when the effective value of any voltage is lower than the corresponding drop threshold voltage.
In step 803, the second feedback adjustment module further adjusts the initial boost current set value according to an error signal between the measured dc bus voltage value and the dc bus voltage set value, so that the first feedback adjustment module outputs an updated PWM signal to make the dc bus voltage approach the dc bus voltage set value during the fault ride-through process.
In step 804, it is determined whether all the effective values of the phase voltages and the line voltages reach the corresponding recovery threshold voltages, and when all the effective values of the phase voltages and the line voltages reach the corresponding recovery threshold voltages, the connection between the second feedback regulation module and the first feedback regulation module is disconnected.
In step 805, the speed limiter is connected in series to the line between the generator and the first feedback regulation module within a predetermined time period after all of the phase voltages and line voltages have reached the corresponding recovery threshold voltages; and after a predetermined period of time, cutting the speed limiter off the line between the generator and the first feedback regulation module.
In step 806, it is determined whether the machine side rectified voltage reaches the starting voltage of the braking unit of the converter, and when the machine side rectified voltage reaches the starting voltage of the braking unit, a control signal for starting the braking unit is outputted.
Fig. 9 is a flowchart illustrating a fault ride-through control method according to another embodiment of the present invention, which is different from fig. 8 in that the fault ride-through control method shown in fig. 9 further includes steps 807 to 806 to 811.
In step 807, the third feedback adjustment module outputs an active current set value of the power grid according to an error signal between the measured value of the dc bus voltage and the set value of the dc bus voltage.
In step 808, the fourth feedback adjustment module outputs a PWM signal for driving an IGBT in the converter according to the active current set value of the grid, the external grid reactive current set value, the phase value output by the phase-locked loop, and the measured value of the three-phase current of the grid.
In step 809, according to the three-phase voltage signal of the power grid, a positive sequence component of the power grid voltage is obtained, based on the positive sequence component of the power grid voltage, a given reactive current value required to be sent by the converter in the fault ride-through process is calculated, when the power grid voltage meets a preset dropping condition, the given reactive current value of the external power grid is suspended, and the given reactive current value required to be sent by the converter is used as a new given reactive current value.
In step 810, the fourth feedback adjustment module further outputs an updated PWM signal according to an active current set value of the grid, a reactive current set value required to be sent by the converter, a phase value output by the phase-locked loop, and a three-phase current measured value of the grid, so that the reactive power output by the converter in the fault ride-through process meets the reactive demand of the grid.
In step 811, it is determined whether all the effective values of the phase voltages and the line voltages have reached the corresponding recovery threshold voltages, and when all the effective values of the phase voltages and the line voltages have reached the corresponding recovery threshold voltages, the given value of the reactive current required to be sent by the converter is stopped, and the given value of the reactive current of the external power grid is recovered.
It should be clear that the embodiments in this specification are described in a progressive manner, and the same or similar parts in the embodiments are referred to each other, and each embodiment focuses on the differences from the other embodiments. For the device embodiments, reference may be made to the description of the method embodiments in the relevant part. Embodiments of the invention are not limited to the specific steps and structures described above and shown in the drawings. Those skilled in the art may make various changes, modifications and additions or change the order between the steps after appreciating the spirit of the embodiments of the invention. Also, a detailed description of known process techniques is omitted herein for the sake of brevity.
The functional blocks shown in the above-described structural block diagrams may be implemented as hardware, software, firmware, or a combination thereof. When implemented in hardware, it may be, for example, an electronic circuit, an Application Specific Integrated Circuit (ASIC), suitable firmware, plug-in, function card, or the like. When implemented in software, the elements of an embodiment of the invention are the programs or code segments used to perform the required tasks. The program or code segments may be stored in a machine-readable medium or transmitted by a data signal carried in a carrier wave over a transmission medium or a communication link. A "machine-readable medium" may include any medium that can store or transfer information. Examples of a machine-readable medium include electronic circuits, semiconductor memory devices, ROM, flash memory, Erasable ROM (EROM), floppy disks, CD-ROMs, optical disks, hard disks, fiber optic media, Radio Frequency (RF) links, and so forth. The code segments may be downloaded via computer networks such as the internet, intranet, etc.
Embodiments of the present invention may be embodied in other specific forms without departing from its spirit or essential characteristics. For example, the algorithms described in the specific embodiments may be modified without departing from the basic spirit of the embodiments of the present invention. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the embodiments of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.
Claims (16)
1. A fault ride-through control device, comprising: the device comprises a control module, a first feedback regulation module and a second feedback regulation module; wherein the content of the first and second substances,
the first feedback adjusting module outputs a Pulse Width Modulation (PWM) signal for driving an Insulated Gate Bipolar Transistor (IGBT) in a machine side boost circuit of the converter according to a boost current measured value and an initial boost current given value;
the control module controls a circuit between the second feedback regulation module and the first feedback regulation module to be connected when the power grid voltage meets a preset dropping condition;
the second feedback adjusting module adjusts the initial boost current given value according to an error signal between a direct current bus voltage measured value and a direct current bus voltage given value, so that the first feedback adjusting module outputs an updated PWM signal, and the direct current bus voltage approaches to the direct current bus voltage given value in a fault ride-through process.
2. The apparatus according to claim 1, wherein the control module comprises a first arithmetic unit, a first judgment unit and a first switch unit; wherein the content of the first and second substances,
the first switch unit is arranged on a line between the first feedback regulation module and the second feedback regulation module;
the first operation unit is used for performing effective value operation on three phase voltages and three line voltages of the power grid by using three-phase voltage signals of the power grid to obtain effective values of all the voltages;
the first judging unit is used for respectively judging whether the effective value of each voltage is lower than the corresponding drop threshold voltage, and when the effective value of any one voltage is lower than the corresponding drop threshold voltage, outputting a first control signal to the first switch unit to switch on a line between the second feedback regulating module and the first feedback regulating module.
3. The apparatus of claim 2, wherein the control module further comprises a second determining unit for determining whether the effective values of all the phase voltages and the line voltages all reach the corresponding recovery threshold voltages, and outputting a second control signal to the first switching unit to disconnect the second feedback regulating module from the first feedback regulating module when the effective values of all the phase voltages and the line voltages all reach the corresponding recovery threshold voltages.
4. The apparatus of claim 3, wherein the control module further comprises a second switching unit and a speed limiter; wherein the content of the first and second substances,
the second switch unit is arranged on a line between a generator of the wind generating set and the first feedback adjusting module;
the second judging unit is further configured to output a third control signal to the second switching unit within a predetermined time period after all the phase voltages and the line voltages reach the corresponding recovery threshold voltages, so that the speed limiter is connected in series to a line between the generator and the first feedback regulating module; and after the predetermined time period, outputting a fourth control signal to the second switching unit to cut the speed limiter off a line between the generator and the first feedback regulation module.
5. The apparatus of claim 1, wherein the initial boost current setpoint is a ratio between an output power of the wind turbine generator set and a machine side rectified voltage;
the control module further comprises a third judging unit for judging whether the machine side rectified voltage or the direct current bus voltage reaches the starting voltage of the braking unit of the converter, and outputting a control signal for starting the braking unit when the machine side rectified voltage or the direct current bus voltage reaches the starting voltage of the braking unit.
6. The apparatus of claim 3, further comprising a third feedback adjustment module, a fourth feedback adjustment module, and a phase locked loop; wherein the content of the first and second substances,
the third feedback adjusting module outputs an active current given value of the power grid according to an error signal between the measured direct current bus voltage value and the given direct current bus voltage value;
the fourth feedback adjusting module outputs a PWM signal for driving an IGBT in a converter according to the active current set value of the power grid, the reactive current set value of the external power grid, the phase value output by the phase-locked loop and the three-phase current measured value of the power grid;
the control module is also used for obtaining a positive sequence component of the power grid voltage according to the three-phase voltage signal of the power grid, calculating a given reactive current value required to be sent by the converter in the fault ride-through process based on the positive sequence component of the power grid voltage, and updating the given reactive current value of the external power grid by using the given reactive current value required to be sent by the converter when the power grid voltage meets a preset dropping condition;
the fourth feedback adjusting module further outputs an updated PWM signal according to the active current set value of the power grid, the reactive current set value required to be sent by the converter, the phase value output by the phase-locked loop and the three-phase current measured value of the power grid, so that the reactive power output by the converter in the fault ride-through process meets the reactive demand of the power grid.
7. The apparatus of claim 6, wherein the control module further comprises a second operation unit and a third switching unit; wherein the content of the first and second substances,
the second operation unit is used for obtaining a positive sequence component of the power grid voltage according to the three-phase voltage signal of the power grid and calculating a reactive current set value required to be sent by the converter in the fault ride-through process according to the positive sequence component of the power grid voltage;
the third switching unit is arranged on a line between the second operation unit and the fourth feedback regulation module;
the first judging unit is further configured to output a fifth control signal to the third switching unit when the effective value of any one of the voltages is lower than the corresponding drop threshold voltage, connect a line between the second operation unit and the fourth feedback adjustment module, suspend the setting of a reactive current set value of an external power grid, and use the reactive current set value required to be sent by the converter as a new reactive current set value.
8. The apparatus of claim 7, wherein the second determining unit is further configured to output a sixth control signal to the third switching unit to disconnect the second feedback regulation module from the first feedback regulation module and restore the given value of the reactive current of the external power grid when the effective values of all the phase voltages and the line voltages all reach the corresponding restoration threshold voltages.
9. The apparatus of claim 6, wherein the control module further comprises a limiter disposed on a line between the third feedback adjustment module and the fourth feedback adjustment module.
10. A fault ride-through control method, comprising:
outputting a PWM signal for driving an IGBT in a machine side boost circuit of the converter by a first feedback regulation module according to a boost current measured value and an initial boost current given value;
when the power grid voltage meets a preset dropping condition, controlling a circuit between a second feedback regulation module and the first feedback regulation module to be connected;
and the second feedback regulation module is used for regulating the initial boost current given value according to an error signal between the measured value of the direct-current bus voltage and the direct-current bus voltage given value, so that the first feedback regulation module outputs an updated PWM signal to enable the direct-current bus voltage to approach the direct-current bus voltage given value in the fault ride-through process.
11. The method according to claim 10, wherein the determining whether the grid voltage meets the preset dropping condition according to the three-phase voltage signal of the grid comprises:
carrying out effective value operation on three phase voltages and three line voltages of the power grid by using the three-phase voltage signals of the power grid to obtain effective values of all the voltages;
and respectively judging whether the effective value of each voltage is lower than the corresponding drop threshold voltage, and determining that the wind generating set is in a fault ride-through working condition when the effective value of any voltage is lower than the corresponding drop threshold voltage.
12. The method of claim 11, further comprising:
and judging whether the effective values of all the phase voltages and the line voltages all reach the corresponding recovery threshold voltages, and disconnecting the second feedback regulation module from the first feedback regulation module when the effective values of all the phase voltages and the line voltages all reach the corresponding recovery threshold voltages.
13. The method of claim 12, further comprising:
in a preset time period after all phase voltages and line voltages reach corresponding recovery threshold voltages, enabling a speed limiter to be connected in series to a line between the generator and the first feedback regulation module; and after the predetermined period of time, cutting the speed limiter off a line between the generator and the first feedback regulation module.
14. The method of claim 10, wherein the initial boost current setpoint is a ratio between an output power of the wind turbine generator set and a machine side rectified voltage; the method further comprises the following steps:
and judging whether the machine side rectified voltage reaches the starting voltage of a braking unit of the converter, and outputting a control signal for starting the braking unit when the machine side rectified voltage reaches the starting voltage of the braking unit.
15. The method of claim 10, further comprising:
outputting an active current given value of the power grid by a third feedback regulation module according to an error signal between the direct current bus voltage measured value and the direct current bus voltage given value;
outputting a PWM signal for driving an IGBT in a converter by a fourth feedback regulation module according to an active current set value of the power grid, an external power grid reactive current set value, a phase value output by a phase-locked loop and a three-phase current measured value of the power grid;
obtaining a positive sequence component of the voltage of the power grid according to the three-phase voltage signal of the power grid, calculating a given reactive current value required to be sent by the converter in the fault ride-through process based on the positive sequence component of the voltage of the power grid, suspending the given reactive current value of the external power grid when the voltage of the power grid meets a preset dropping condition, and taking the given reactive current value required to be sent by the converter as a new given reactive current value;
and the fourth feedback regulation module outputs an updated PWM signal according to the active current set value of the power grid, the reactive current set value required to be sent by the converter, the phase value output by the phase-locked loop and the three-phase current measured value of the power grid, so that the reactive power output by the converter in the fault ride-through process meets the reactive requirement of the power grid.
16. The method of claim 15, further comprising:
and judging whether the effective values of all the phase voltages and the line voltages all reach the corresponding recovery threshold voltages, and stopping giving the given reactive current given values required to be sent by the converter and recovering the given reactive current given values of the external power grid when the effective values of all the phase voltages and the line voltages all reach the corresponding recovery threshold voltages.
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| CN112134302B (en) * | 2020-08-31 | 2023-04-07 | 中国东方电气集团有限公司 | Fan high voltage ride through control system based on direct current bus voltage regulation |
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Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE102008018497A1 (en) * | 2008-04-11 | 2009-10-22 | Siemens Aktiengesellschaft | Inverter i.e. solar inverter, for feeding multi-phase line current into mixing point of power network, has downstream line filter that is active line filter connected parallel to output of inverter |
| CN102130465A (en) * | 2010-01-20 | 2011-07-20 | 陈荣 | Direct-drive wind power generation alternating current/direct current conversion circuit and control method |
| CN102280901A (en) * | 2011-07-01 | 2011-12-14 | 大连理工大学 | Low-voltage ride-through control device and control method for compound type wind generator set |
| CN104796065A (en) * | 2015-05-04 | 2015-07-22 | 苏州常实工业设备有限公司 | Control circuit of wind-solar grid-connected power generation system on expressway |
| CN105633997A (en) * | 2014-11-04 | 2016-06-01 | 国家电网公司 | Wind generating set voltage crossing control method and device |
-
2017
- 2017-12-29 CN CN201711479338.XA patent/CN109995068B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE102008018497A1 (en) * | 2008-04-11 | 2009-10-22 | Siemens Aktiengesellschaft | Inverter i.e. solar inverter, for feeding multi-phase line current into mixing point of power network, has downstream line filter that is active line filter connected parallel to output of inverter |
| CN102130465A (en) * | 2010-01-20 | 2011-07-20 | 陈荣 | Direct-drive wind power generation alternating current/direct current conversion circuit and control method |
| CN102280901A (en) * | 2011-07-01 | 2011-12-14 | 大连理工大学 | Low-voltage ride-through control device and control method for compound type wind generator set |
| CN105633997A (en) * | 2014-11-04 | 2016-06-01 | 国家电网公司 | Wind generating set voltage crossing control method and device |
| CN104796065A (en) * | 2015-05-04 | 2015-07-22 | 苏州常实工业设备有限公司 | Control circuit of wind-solar grid-connected power generation system on expressway |
Non-Patent Citations (2)
| Title |
|---|
| 基于串联制动电阻的恒速风电机组故障穿越改善措施;王虹富;《华东电力》;20080930;第36卷(第9期);第28-32页 * |
| 大电网末端风力发电系统故障穿越关键技术;李晖 等;《高压电器》;20170131;第53卷(第1期);第192-196页 * |
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