CN112152215B - Filter capacitor operation control device and method of converter - Google Patents
Filter capacitor operation control device and method of converter Download PDFInfo
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- CN112152215B CN112152215B CN201910579750.1A CN201910579750A CN112152215B CN 112152215 B CN112152215 B CN 112152215B CN 201910579750 A CN201910579750 A CN 201910579750A CN 112152215 B CN112152215 B CN 112152215B
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- 239000003990 capacitor Substances 0.000 title claims abstract description 252
- 238000000034 method Methods 0.000 title claims abstract description 52
- 230000004044 response Effects 0.000 claims description 30
- 238000004590 computer program Methods 0.000 claims description 5
- 230000008569 process Effects 0.000 description 8
- 238000010586 diagram Methods 0.000 description 3
- 238000005516 engineering process Methods 0.000 description 2
- 238000010248 power generation Methods 0.000 description 2
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- 238000010276 construction Methods 0.000 description 1
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Classifications
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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
- H02J3/01—Arrangements for reducing harmonics or ripples
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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
- H02J3/12—Circuit arrangements for ac mains or ac distribution networks for adjusting voltage in ac networks by changing a characteristic of the network load
- H02J3/16—Circuit arrangements for ac mains or ac distribution networks for adjusting voltage in ac networks by changing a characteristic of the network load by adjustment of reactive power
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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
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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
- Y02E40/40—Arrangements for reducing harmonics
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Abstract
The disclosure provides a filter capacitor operation control device and method of a current transformer, wherein the current transformer comprises a filter capacitor module, and the device is characterized in that: the converter controller is used for respectively sending filter capacitor input control signals to the trigger module and the contactor module; the trigger module is used for detecting a voltage signal of the power grid and sending a trigger signal to the thyristor module according to the filter capacitor input control signal and the voltage signal; the thyristor module is used for conducting the thyristors in the thyristor module according to the trigger signal and the voltage signal so that the power grid is connected with the filter capacitor module through the conducted thyristors; and the contactor module is used for connecting the filter capacitor module with a power grid according to the filter capacitor input control signal, wherein when the contactor module is conducted, the power grid is connected with the filter capacitor module through the contactor module so as to bypass the thyristor module.
Description
Technical Field
The present disclosure relates to the field of wind power generation technologies, and more particularly, to a filter capacitor operation control device of a converter and a filter capacitor operation control method performed by the filter capacitor operation control device.
Background
With the development of wind power technology, the full-power converter is widely applied to the full-power wind turbine generator, and the LCL filter is a grid-side filter of the full-power converter and is used for filtering grid-side current harmonic waves, so that the electric energy quality of the wind turbine generator meets the power grid requirement and can be smoothly connected with a grid, and the LCL filter consists of a box transformer leakage inductance, a filter capacitor and a reactor.
At present, a contactor switching mode is adopted for switching the grid-side filter capacitor of the wind power converter. As shown in fig. 1, wherein 1 denotes a circuit breaker, 2 denotes a reactor, 3 denotes a contactor, and 4 denotes a filter capacitor module. When the filter capacitor is put into the power grid, the contactor switching mode is adopted, and the contactor and the filter capacitor can be impacted by tens of times rated current when being put into the power grid, so that the service lives of the contactor and the filter capacitor are seriously influenced, and the conditions of damage of the filter capacitor, adhesion of main contacts of the contactor and the like can be caused.
Disclosure of Invention
Exemplary embodiments of the present disclosure provide a filter capacitor operation control device and method of a current transformer, at least solving the above technical problems and other technical problems not mentioned above, and providing the following advantages.
An aspect of the present disclosure is to provide a filter capacitor operation control device of a current transformer, where the current transformer includes a filter capacitor module, and the device may include: the converter controller is used for respectively sending filter capacitor input control signals to the trigger module and the contactor module; the trigger module is used for detecting a voltage signal of the power grid and sending a trigger signal to the thyristor module according to the filter capacitor input control signal and the voltage signal; the thyristor module is used for conducting the thyristors in the thyristor module according to the trigger signal and the voltage signal so that the power grid is connected with the filter capacitor module through the conducted thyristors; and the contactor module is used for connecting the filter capacitor module with a power grid according to the filter capacitor input control signal, wherein when the contactor module is conducted, the power grid is connected with the filter capacitor module through the contactor module so as to bypass the thyristor module.
The thyristor module may comprise 6 thyristors and the filter capacitor module comprises a three-phase filter capacitor, wherein the first thyristor and the second thyristor form a control valve of the grid a phase for controlling the connection of the first filter capacitor to the grid a phase, the third thyristor and the fourth thyristor form a control valve of the grid B phase for controlling the connection of the second filter capacitor to the grid B phase, and the fifth thyristor and the sixth thyristor form a control valve of the grid C phase for controlling the connection of the third filter capacitor to the grid C phase.
The trigger module can send trigger signals to the gate electrode of each of the 6 thyristors based on the amplitude and the phase of the power grid voltage, wherein each thyristor in the thyristor module is conducted according to the trigger signals received by the corresponding gate electrode and the voltage signals at two ends of each thyristor, so that A phase, B phase and C phase in the power grid are respectively connected with corresponding filter capacitors in the filter capacitor module through the conducted thyristors.
When the amplitude of the power grid voltage is detected to be reduced to a low voltage standard, if the power grid is connected with the filter capacitor module through the contactor module, responding to a filter capacitor input control signal, and conducting a thyristor in the thyristor module so that the power grid is connected with the filter capacitor module through the conducting thyristor module; and if the power grid is not connected with the filter capacitor module through the contactor module but is connected with the thyristor module, waiting for the voltage signal to return to normal.
When the power grid voltage is recovered to be normal, the contactor module is conducted so that the power grid and the filter capacitor module are connected through the conducted contactor module, and the thyristor module is disconnected.
The trigger module can respond to the filter capacitor cut-out control signal sent by the converter controller, send the trigger signal to the thyristor module again, the thyristor module is conducted according to the trigger signal, the contactor module responds to the filter capacitor cut-out control signal to be disconnected, and the filter capacitor module is cut out from the power grid after preset time.
The thyristor module may be responsive to the trigger signal disappearing, the thyristors in the thyristor module being all turned off according to the filtered current zero crossing and the voltage signal from the trigger module.
Another aspect of the present disclosure is to provide a filter capacitor operation control method performed by a filter capacitor operation control device of a current transformer, the current transformer including a filter capacitor module, the filter capacitor operation control device including a current transformer controller, a trigger module, a thyristor module, and a contactor module, wherein the method may include: detecting a voltage signal of the power grid by a trigger module; the converter controller sends a filter capacitor input control signal to the trigger module and the contactor module; the triggering module sends a triggering signal to the thyristor module according to the detected voltage signal and the filter capacitor input control signal; responding to the trigger signal, and conducting the thyristors in the thyristor module according to the detected voltage signal by the thyristor module so that the power grid is connected with the filter capacitor module in the converter through the conducted thyristors; in response to the filter capacitor input control signal, the power grid is connected with the filter capacitor module by the contactor module, wherein the thyristor module is bypassed when the power grid is connected with the filter capacitor module via the conductive contactor module.
The thyristor module may comprise 6 thyristors and the filter capacitor module comprises a three-phase filter capacitor, wherein the first thyristor and the second thyristor form a control valve of the grid a phase for controlling the connection of the first filter capacitor to the grid a phase, the third thyristor and the fourth thyristor form a control valve of the grid B phase for controlling the connection of the second filter capacitor to the grid B phase, and the fifth thyristor and the sixth thyristor form a control valve of the grid C phase for controlling the connection of the third filter capacitor to the grid C phase.
The step of connecting the grid with the filter capacitor module by the thyristor module according to the detected voltage signal may comprise: and sending a trigger signal to the gate electrode of each thyristor in the 6 thyristors by the trigger module based on the amplitude and the phase of the power grid voltage, and conducting each thyristor in the thyristor module according to the trigger signal received by the corresponding gate electrode and the voltage signals at two ends of each thyristor, so that the phase A, the phase B and the phase C in the power grid are respectively connected with the corresponding filter capacitor in the filter capacitor module through the conducted thyristors.
The method may further comprise: in response to a filter capacitor cut-out control signal sent by the converter controller, sending a trigger signal to the thyristor module again by the trigger module, and conducting the thyristor module according to the trigger signal; and responding to the filter capacitor cut-out control signal, disconnecting the contactor module, and cutting out the filter capacitor module from the power grid after a preset time.
The method may further comprise: in response to the trigger signal disappearing, all thyristors in the thyristor module are turned off by the thyristor module according to the filtered current zero crossing point and the voltage signal from the trigger module.
Another aspect of the present disclosure is to provide a filter capacitor operation control method performed by a filter capacitor operation control device of a current transformer, the current transformer including a filter capacitor module, the filter capacitor operation control device including a current transformer controller, a trigger module, a thyristor module, and a contactor module, wherein the method may include: detecting a voltage signal of the power grid by a trigger module; when the detected voltage signal meets the low voltage standard, determining by the trigger module whether the filter capacitor module has been put into the power grid by the contactor module; when it is determined that the filter capacitor module is put into the power grid via the contactor module, the thyristors in the thyristor module are turned on in response to the filter capacitor put control signal, so that the power grid and the filter capacitor module are connected by the turned-on thyristor module.
The method may further comprise: when the detected voltage signal meets the low voltage standard and it is determined that the filter capacitor module is not put into the power grid through the contactor module, determining by the trigger module whether to put the filter capacitor module into the power grid through the thyristor module, wherein when it is determined that the filter capacitor module is put into the power grid through the thyristor module, waiting for the voltage signal to return to normal, and when it is determined that the filter capacitor module is not put into the power grid through the thyristor module, turning off the converter.
The method may further comprise: and after the voltage of the power grid is recovered to be normal, the contactor module is conducted, so that the power grid is connected with the filter capacitor module through the conducted contactor module, and the thyristor module is disconnected.
Another aspect of the present disclosure is to provide a computer comprising a readable medium storing a computer program, characterized in that the computer program comprises instructions for performing the above method.
Based on the method and the device, the switching characteristic of the thyristor is utilized to assist the contactor to switch the filter capacitor, so that the impulse current of the filter capacitor is small, and the required external signals are small, thereby prolonging the service lives of the contactor and the filter capacitor. Meanwhile, the thyristor can be adopted to pass the process of disconnecting the contactor during low voltage ride through, and the control coil of the contactor is peeled off from the power supply of the UPS, so that the capacity of an alternating current Uninterruptible Power Supply (UPS) is reduced.
Drawings
These and/or other aspects and advantages of the present disclosure will become apparent from the following description of the embodiments, taken in conjunction with the accompanying drawings, in which:
FIG. 1 is a block diagram of a prior art filter capacitor switching device;
fig. 2 is a block diagram of a filter capacitor switching device of a current transformer according to an exemplary embodiment of the present disclosure;
Fig. 3 is a flowchart of a filter capacitor operation control method of a current transformer according to a first exemplary embodiment of the present disclosure;
fig. 4 is a flowchart of a filter capacitor operation control method of a current transformer according to a second exemplary embodiment of the present disclosure;
fig. 5 is a flowchart of a filter capacitor operation control method of a current transformer according to a third exemplary embodiment of the present disclosure.
Detailed Description
The following description with reference to the accompanying drawings is provided to assist in a comprehensive understanding of the embodiments of the disclosure defined by the claims and their equivalents. Various specific details are included to aid understanding, but are merely to be considered exemplary. Accordingly, one of ordinary skill in the art will recognize that various changes and modifications of the embodiments described herein can be made without departing from the scope and spirit of the present disclosure. In addition, descriptions of well-known functions and constructions are omitted for clarity and conciseness.
In this disclosure, terms including ordinal numbers such as "first," "second," and the like may be used to describe various elements, but these elements should not be construed as limited to only these terms. These terms are only used to distinguish one element from another element. For example, a first element could be termed a second element, and vice versa, without departing from the scope of the present disclosure.
Hereinafter, according to various embodiments of the present disclosure, the apparatus and method of the present disclosure will be described with reference to the accompanying drawings.
Fig. 2 is a block diagram of a filter capacitor operation control device of a current transformer according to an exemplary embodiment of the present disclosure.
Referring to fig. 2, the filter capacitor operation control device 200 of the current transformer may be included in a wind power current transformer (not shown). The filter capacitor operation control device 200 of the current transformer may include a current transformer controller 201, a trigger module 202, a thyristor module 203, a contactor module 204, and a filter capacitor module 205. Each module in the apparatus 200 according to the present disclosure may be implemented by one or more modules, and the names of the corresponding modules may vary according to the types of the modules. In various embodiments, some modules in apparatus 200 may be omitted, or additional modules may be included. Furthermore, modules/elements according to various embodiments of the present disclosure may be combined to form a single entity, and thus the functions of the respective elements prior to combination may be equivalently performed.
The converter controller 201 is a control module, and is mainly used for sending a filter capacitor input control signal and a filter capacitor cut-out control signal. As shown in fig. 2, a first pin of the current transformer controller 201 is connected to a first pin of the trigger module 202, and a second pin of the current transformer controller 201 is connected to a second pin of the trigger module 202, thereby providing 24V power to the trigger module 202 via the current transformer controller 201. The third pin of the current transformer controller 201 is connected with the third pin of the trigger module 202 and is connected with the seventh pin of the contactor module 204, the fourth pin of the current transformer controller 201 is connected with the fourth pin of the trigger module 202 and is connected with the eighth pin of the contactor module 204, so that control signals are respectively sent to the trigger module 202 and the contactor module 204 through the current transformer controller 201, namely input signals and cut-out signals of the filter capacitor module 205 in a power grid are provided.
The trigger module 202 is a module for collecting signals and outputting trigger signals, and is mainly used for detecting voltage signals of a power grid and determining whether to send the trigger signals according to the filter capacitor input control signals and the voltage signals. As shown in fig. 2, the fifth pin of the trigger module 202 is connected to the first pin of the contactor module 204 (i.e., phase a of the power grid), the sixth pin of the trigger module 202 is connected to the third pin of the contactor module 204 (i.e., phase B of the power grid), and the seventh pin of the trigger module 202 is connected to the fifth pin of the contactor module 204 (i.e., phase C of the power grid), thereby detecting the voltage signal of the power grid via the trigger module 202.
The thyristor module 203 may include 6 thyristors, i.e., a first thyristor T1, a second thyristor T2, a third thyristor T3, a fourth thyristor T4, a fifth thyristor T5, and a sixth thyristor T6, and is mainly used to conduct the thyristors in the thyristor module according to the trigger signal and the voltage signal so that the power grid and the filter capacitor module 205 are connected through the conducted thyristors. Specifically, as shown in fig. 2, the eighth pin of the trigger module 202 is connected to the gate (G-pole) of the thyristor T5 in the thyristor module 203, the ninth pin of the trigger module 202 is connected to the G-pole of the thyristor T6 in the thyristor module 203, the tenth pin of the trigger module 202 is connected to the G-pole of the thyristor T3 in the thyristor module 203, the eleventh pin of the trigger module 202 is connected to the G-pole of the thyristor T4 in the thyristor module 203, the twelfth pin of the trigger module 202 is connected to the G-pole of the thyristor T1 in the thyristor module 203, and the thirteenth pin of the trigger module 202 is connected to the G-pole of the thyristor T2 in the thyristor module 203, so that a trigger signal is transmitted to the G-stage of each thyristor in the thyristor module 203 via the trigger module 202.
In addition, the anode (i.e., the a pole) of the thyristor T1 is connected to the first pin of the contactor module 204, the cathode (i.e., the K pole) of the thyristor T1 is connected to the second pin of the contactor module 204, the a pole of the thyristor T2 is connected to the K pole of the thyristor T1, the K pole of the thyristor T2 is connected to the a pole of the thyristor T1, and the thyristor T1 and the thyristor group T2 constitute a control valve of the grid a phase. The A pole of the thyristor T3 is connected with the third pin of the contactor module 204, the K pole of the thyristor T3 is connected with the fourth pin of the contactor module 204, the A pole of the thyristor T4 is connected with the K pole of the thyristor T3, the K pole of the thyristor T4 is connected with the A pole of the thyristor T3, and the thyristor T3 and the thyristor T4 form a control valve of the B phase of the power grid. The A pole of the thyristor T5 is connected with the fifth pin of the contactor module 204, the K pole of the thyristor T5 is connected with the sixth pin of the contactor module 204, the A pole of the thyristor T6 is connected with the K pole of the thyristor T5, the K pole of the thyristor T6 is connected with the A pole of the thyristor T5, and the thyristor T5 and the thyristor T6 form a control valve of a power grid C phase.
In the present disclosure, the function of the thyristor module 203 is to put the thyristor into the power grid according to the trigger signal of the G pole and the phase of the power grid voltage by utilizing the on and off characteristics of the thyristor under the condition that the control valve of the power grid a phase is composed of the thyristor T1 and the thyristor T2, the control valve of the power grid B phase is composed of the thyristor T3 and the thyristor T4, and the control valve of the power grid C phase is composed of the thyristor T5 and the thyristor T6, so as to ensure that no impact current is generated due to the overlarge phase difference between the power grid voltage and the capacitor initial voltage, thereby improving the service life of the contactor and the service life of the filter capacitor.
The filter capacitor module 205 may include three-phase filter capacitors, i.e., a first filter capacitor C1, a second filter capacitor C2, and a third filter capacitor C3. The contactor module 204 connects the filter capacitor module 205 to the grid according to the filter capacitor input control signal. As shown in fig. 2, the first pin of the contactor module 204 is connected to the a of the power grid, the second pin of the contactor module 204 is connected to the first pin of the capacitor C1 in the filter capacitor module 205, the third pin of the contactor module 204 is connected to the B of the power grid, the fourth pin of the contactor module 204 is connected to the first pin of the capacitor C2 in the filter capacitor module 205, the fifth pin of the contactor module 204 is connected to the C of the power grid, and the sixth pin of the contactor module 204 is connected to the first pin of the capacitor C3 in the filter capacitor module 205. Phase a, phase B and phase C of the power grid can be connected to filter capacitors C1, C2 and C3, respectively, via the touch module 204.
In addition, the second pins of the filter capacitors C1, C2 and C3 in the filter capacitor module 205 are all grounded.
When the filter capacitor module 205 is put into the power grid, the filter capacitor in the filter capacitor module 205, the inductance in the converter and the leakage inductance in the tank transformer of the power grid can form an LCL filter loop. The LCL filter circuit can effectively filter harmonic waves in a high-power converter and an inverter, so that grid-connected equipment meets the requirement of a power grid, and the LCL filter circuit is a power grid filter circuit of the new energy power generation system which is most widely applied at present.
The operation of each module in the filter capacitor operation control device 200 will be described in detail with reference to fig. 2.
After the converter is powered up, the triggering module 202 detects the voltage signal of the power grid in real time. When the converter controller 201 sends the filter capacitor input control signal to the trigger module 202 and the contactor module 204, respectively, the trigger module 202 sends the trigger signal to the thyristor module 203 according to the filter capacitor input control signal and the voltage signal. Specifically, in response to the filter capacitor input control signal being 1, the trigger module 202 collects A, B, C three-phase voltage signals of the power grid through the fifth, sixth and seventh pins as the basis of trigger judgment, sends trigger signals to the G pole of each thyristor in the thyristor module 203 based on the amplitude and phase of the power grid voltage, and each thyristor can be conducted according to the trigger signals received by the corresponding G pole and the voltage signals at two ends of each thyristor, so that the corresponding phase (i.e., the a phase, the B phase and the C phase of the power grid) in the power grid is connected with the filter capacitor module 205 through the conducted thyristors. In this way, the characteristics of the thyristors can be used to assist the contactor module 204 in switching the filter capacitor, so as to avoid the reduction of the service lives of the contactor and the filter capacitor due to the large impact current when the filter capacitor is switched in.
In addition, in response to the filter capacitor input control signal being 1, the contactor in the contactor module 204 is closed, and the filter capacitor module 205 is connected with the power grid via the contactor, so that the thyristor module is bypassed, and thus, the loss of the system is reduced. Next, the thyristor module 203 disappears in response to the trigger signal, and the thyristors in the thyristor module 203 are all turned off according to the filtered current zero crossing and voltage signal from the trigger module 202.
It should be noted that since the contactor takes several tens of milliseconds from the reception of the filter capacitance on control signal to the closing of the contactor, and the thyristor can be operated immediately after the reception of the filter capacitance on control signal, the thyristor module 203 and the contactor module 204 can use the same control signal.
After the filter capacitor module 205 is put into the power grid, an LCL filter loop is formed by the filter capacitor module, the internal inductance of the converter and leakage inductance of the tank transformer.
In addition, the converter controller 201 may also send a filter capacitor cut-out control signal to the contactor module 204. In response to the filter capacitor cut-out control signal being 1, a trigger signal is sent out by the trigger module 202, and the contactor is opened, and the filter capacitor module 205 is put into the power grid through the thyristor module 203. The trigger module 202 turns off the trigger signal after detecting a feedback signal of the contactor opening. The thyristor turns off when the filter current crosses zero, so that the filter capacitor module 205 is cut off from the grid.
According to an embodiment of the present disclosure, when it is detected that the magnitude of the grid voltage is reduced to the low voltage level during the connection of the grid and the filter capacitor module 205 via the contactor module 204, the contactor module 204 is turned off under voltage in response to the filter capacitor input control signal being 1, and the thyristors in the thyristor module 203 are turned on so that the grid and the filter capacitor module 205 are connected through the turned-on thyristor module 203. When the grid voltage returns to normal, the contactor module 204 is turned on so that the grid and the filter capacitor module 205 are connected through the turned-on contactor module 204 and the thyristor module 203 is turned off.
Fig. 3 is a flowchart of a filter capacitor operation control method of a current transformer according to an exemplary embodiment of the present disclosure. The filter capacitor operation control method of fig. 3 can be applied to the case that the power grid is in the normal operation mode.
In step S301, the converter is started.
When the converter is started, in step S302, the trigger module 202 in the filter capacitor operation control device 200 collects/detects the voltage signal of the power grid in real time.
In step S303, when the converter controller 201 transmits a filter capacitor input control signal, that is, the filter capacitor input control signal is 1, the flow advances to step S304. Here, it should be noted that the filter capacitance input control signal is used to input the filter capacitance into the power grid only in the case where the transmitted filter capacitance input control signal is 1. Otherwise, the voltage signal of the power grid continues to be acquired/detected by the triggering module 202.
In step S304, the trigger module 202 sends a trigger signal to the G pole of the thyristor in the thyristor module 203 according to the collected voltage phase in response to receiving the filter capacitor input control signal.
In step S305, after the thyristor module 203 receives the trigger signal, the thyristors in the thyristor module 203 are turned on according to the trigger signal received by the G pole and the voltages at the two ends of the thyristors, so that the a phase, the B phase and the C phase in the power grid are respectively connected with the filter capacitors in the filter capacitor module 205 through the turned-on thyristors. In this way, the filter capacitance can be first put into the grid via the thyristor module 203. In the method, the thyristor is put into the gate according to the trigger signal of the G pole and the phase of the grid voltage by utilizing the on-off characteristics of the thyristor, so that the impact current cannot be generated due to the fact that the grid voltage and the initial voltage of the capacitor are excessively different.
In addition, in step S306, in response to receiving the filter capacitor input control signal, the contactor in the contactor module 204 is closed, i.e. the contactor is turned on, after a fixed time delay, and the power grid is connected to the filter capacitor module 205 via the turned-on contactor. When the grid is connected to the filter capacitor module 205 via the contactor module 204, the thyristor module 203 is bypassed.
Since the contactor takes several tens of milliseconds from receiving the filter capacitor input control signal to the actuation, and the thyristor can act immediately after receiving the control signal, in the case that the thyristor module 203 and the contactor module 204 use the same control signal, the filter capacitor is first connected to the power grid via the turned-on thyristor, and then connected to the power grid via the turned-on contactor, at this time, the thyristor module 203 is bypassed, thereby reducing the loss of the system.
In step S307, in response to the contactor in the contactor module 204 being turned on, the trigger signal is disappeared, and in response to the trigger signal being disappeared, the thyristor is cut out due to the small current flow caused by the input of the contactor. The thyristors in the thyristor module 203 are all turned off by the thyristor module 203 based on the filtered current zero crossing and voltage signal from the trigger module 202. When the trigger signal of the trigger module 202 disappears, the thyristor module 203 is completely turned off under the action of the zero crossing current and the voltages at the two ends of the thyristor.
In the case where the filter capacitor is connected to the power grid by the contactor module 204, when the converter controller 201 issues a filter capacitor cut-out control signal in step S308, the process proceeds to step S309, and in response to the filter capacitor cut-out control signal being 1, a trigger signal is issued to the thyristor module 203 by the trigger module 202.
In step S310, the thyristor module 203 is turned on in response to the trigger signal.
In step S311, the contactor in the contactor module 204 is opened in response to the filter capacitance cut-out control signal being 1.
In step S312, the trigger turns off the trigger signal in response to the feedback signal that the contactor module 204 is open.
In step S313, in response to the trigger signal disappearing, the thyristor is turned off all according to the filter current zero-crossing point and the voltage signal, thereby cutting the filter capacitor from the power grid.
Fig. 4 is a flowchart of a filter capacitor operation control method of a current transformer according to another exemplary embodiment of the present disclosure. The filter capacitor operation control method of fig. 4 may be applied to a case where low voltage ride through occurs during the input of the filter capacitor module 205 to the power grid via the contactor module.
Referring to fig. 4, in step S401, when the converter is operating normally, the triggering module 202 detects the voltage signal of the power grid in real time.
In step S402, when the detected voltage signal meets the low voltage standard, the process proceeds to step S403, otherwise, the converter continues to operate normally. Here, since the contactors in the contactor module 204 cannot function properly due to a low voltage when the voltage signal of the power grid reaches a low voltage standard, it may be necessary to put a filter capacitor into the power grid using the thyristor module 203.
In step S403, when the filter capacitance input control signal transmitted from the converter controller 201 is 1, the flow advances to step S404. Here, it should be noted that the filter capacitance drop control signal is used to drop the filter capacitance into the power grid only in the case where the transmitted filter capacitance drop control signal is 1.
When the filter capacitor input control signal transmitted by the converter controller 201 is 0, the filter capacitor module 205 is not input to the power grid.
In step S404, in response to the filter capacitance input control signal being 1, a trigger signal is sent by the trigger module 202 to the G pole of the thyristor in the thyristor module 203 according to the phase of the detected voltage.
In step S405, after the thyristor module 203 receives the trigger signal, the thyristors in the thyristor module 203 are turned on according to the trigger signal received by the G pole and the voltages at the two ends of the thyristors, so that the a phase, the B phase and the C phase in the power grid are respectively connected with the filter capacitors in the filter capacitor module 205 through the turned-on thyristors.
In step S406, after connecting the grid and the filter capacitor via the thyristor module 203, the contactor is opened due to the control coil losing voltage.
After the delay time 2S specified by the low voltage ride through procedure has elapsed, in step S407, the trigger module 202 continues to detect the voltage signal of the power grid, and determines whether the power grid voltage is recovered to be normal. When the detected voltage is a low voltage, the flow advances to step S410. When the detected voltage returns to normal, the flow advances to step S408.
After the grid voltage is restored to the normal state in step S408, if the converter controller 201 sends a filter capacitor input control signal, the process proceeds to step S409, where the contactor control coil of the contactor module 204 is waited for power on, the contactor module 204 is used to connect the grid with the filter capacitor, and then, in step S410, in response to the feedback signal of the contactor on, the trigger signal sent by the trigger module 202 is turned off, that is, the trigger signal disappears.
In step S411, in response to the trigger signal disappearing, the thyristor module is disconnected at the current zero crossing point, so that the filter capacitor is connected to the power grid via the contactor module, thereby restoring the normal operation state.
In step S407, if the voltage of the power grid is not recovered, the process proceeds to step S410, where the trigger signal from the trigger module 202 is turned off. Accordingly, the thyristor is turned off. Here, it should be noted that in the case where the voltage is not recovered to be normal, step S410 is simply to turn off the trigger signal.
Fig. 5 is a flowchart of a filter capacitor operation control method of a current transformer according to a third exemplary embodiment of the present disclosure. The filter capacitor operation control method of fig. 5 considers the case where neither the contactor module 204 nor the thyristor module 203 is interposed between the power grid and the filter capacitor module 205.
Referring to fig. 5, in step S501, when the converter is operating normally, the triggering module 202 detects the voltage signal of the power grid in real time.
In step S502, when the detected voltage meets the low voltage standard, the process proceeds to step S503, otherwise, the converter continues to operate normally. Here, since the contactors in the contactor module 204 cannot function properly due to the low voltage when the voltage of the power grid reaches the low voltage standard, it may be necessary to throw the filter capacitor module into the power grid using the thyristor module 203.
In step S503, it is determined by the triggering module 202 whether the filter capacitor module 205 is put into the power grid via the contactor module 204 at this time at the time of low voltage ride through. Here, the triggering module 202 may determine whether to put the filter capacitor module 205 into the power grid via the thyristor module according to feedback signals of the contactor being opened and closed. When it is determined that the filter capacitor module 205 is put into the power grid via the contactor module 204, the flow proceeds to step S504, where the converter controller 201 issues a filter capacitor put control signal, and in response to the filter capacitor put control signal being 1, the trigger module 202 sends a trigger signal to the G pole of the thyristor in the thyristor module 203 according to the detected phase of the voltage.
In step S505, after the thyristor module 203 receives the trigger signal, the thyristors in the thyristor module 203 are turned on according to the trigger signal received by the G pole and the voltages at the two ends of the thyristors, so that the a phase, the B phase and the C phase in the power grid are respectively connected with the filter capacitors in the filter capacitor module 205 through the turned-on thyristors.
In step S506, after the grid and the filter capacitor module 205 are connected via the thyristor module 203, the contactor is opened due to the control coil losing voltage.
After the delay time 2S specified by the low voltage ride through procedure has elapsed, in step S507, the trigger module 202 continues to detect the voltage signal of the power grid, and determines whether the power grid voltage is recovered to be normal. When the detected voltage is a low voltage, the process advances to step S510. When the detected voltage returns to normal, the flow advances to step S508.
After the grid voltage is restored to the normal state in step S508, if the converter controller 201 sends a filter capacitor input control signal, the process proceeds to step S509, and the contactor control coil of the contactor module 204 is waited for power on, and the contactor module 204 is used to connect the grid with the filter capacitor, and then, in step S510, the trigger signal sent by the trigger module 202 is turned off, that is, the trigger signal disappears.
In step S511, in response to the disappearance of the trigger information, the thyristor module 203 is disconnected, so that the filter capacitor is connected to the power grid via the contactor module 204, thereby restoring the normal operation state.
In step S507, if the voltage of the power grid is not recovered, the flow proceeds to step S510, where the trigger signal from the trigger module 202 is turned off. Accordingly, the thyristor is turned off. Here, it should be noted that in the case where the voltage is not recovered to be normal, step S510 is simply to turn off the trigger signal.
Further, when it is determined in step S503 that the filter capacitance module 205 is not put into the power grid via the contactor module 204, it is determined by the trigger module 202 in step S512 whether the filter capacitance module 205 is put into the power grid via the thyristor module 203. Here, the triggering module 202 may determine whether to put the filter capacitor module 205 into the power grid via the thyristor module 203 according to feedback signals of the thyristor being turned off and on.
When it is determined in step S512 that the filter capacitor module 205 is put into the power grid via the thyristor module 203, the flow proceeds to step S507, where the trigger module 202 detects whether the voltage of the power grid is recovered to be normal.
When it is determined in step S512 that the filter capacitor module 205 is not put into the power grid via the thyristor module 203, the converter is turned off, i.e., the control flow is ended.
According to the embodiment of the disclosure, the contactor is assisted to switch the filter capacitor by the characteristics of the thyristor, so that the impact current is small when the filter capacitor is switched in, the service life of the contactor and the service life of the filter capacitor are greatly improved, and the low-voltage ride through can be successfully completed under the condition that the contactor does not use UPS by controlling the switching of the thyristor.
The device and the method can be applied to the running wind generating set to prolong the service lives of the contactor and the filter capacitor, and can also be applied to the design of a novel wind generating set, so that the filter capacitor and the contactor meet the requirements of the wind generating set on the service life and maintenance.
The method according to the present disclosure may be performed according to computer program instructions. Because such program instructions may be included in a computer, special purpose processor, or programmable or dedicated hardware, the instructions executed therein may facilitate the performance of the functions described above. As will be appreciated by one of skill in the art, a computer, processor, or programmable hardware includes a storage device that can store or receive software or computer code that, when accessed and executed by a computer, processor, or hardware, implements the methods described in this disclosure.
While the present disclosure has been shown and described with reference to exemplary embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present disclosure as defined by the appended claims and their equivalents.
Claims (14)
1. A filter capacitor operation control device for a current transformer, the current transformer including a filter capacitor module, the device comprising:
The converter controller is used for respectively sending filter capacitor input control signals to the trigger module and the contactor module;
the trigger module is used for detecting a voltage signal of the power grid and sending a trigger signal to the thyristor module according to the filter capacitor input control signal and the voltage signal;
the thyristor module is used for conducting the thyristors in the thyristor module according to the trigger signal and the voltage signal so that the power grid is connected with the filter capacitor module through the conducted thyristors;
The contactor module is used for connecting the filter capacitor module with a power grid according to the filter capacitor input control signal,
Wherein when the contactor module is conducted, the power grid is connected with the filter capacitor module through the contactor module to bypass the thyristor module,
When the amplitude of the power grid voltage is detected to be reduced to a low voltage standard, if the power grid is connected with the filter capacitor module through the contactor module, responding to a filter capacitor input control signal, and conducting a thyristor in the thyristor module so that the power grid is connected with the filter capacitor module through the conducting thyristor module; and if the power grid is not connected with the filter capacitor module through the contactor module but connected with the filter capacitor module through the thyristor module, waiting for the power grid voltage signal to return to normal.
2. The apparatus of claim 1, wherein the thyristor module comprises 6 thyristors and the filter capacitor module comprises a three-phase filter capacitor,
The control valve of the grid A phase is formed by the first thyristor and the second thyristor and used for controlling the connection of the first filter capacitor and the grid A phase, the control valve of the grid B phase is formed by the third thyristor and the fourth thyristor and used for controlling the connection of the second filter capacitor and the grid B phase, and the control valve of the grid C phase is formed by the fifth thyristor and the sixth thyristor and used for controlling the connection of the third filter capacitor and the grid C phase.
3. The apparatus of claim 2, wherein the triggering module sends a trigger signal to a gate of each of the 6 thyristors based on a magnitude and a phase of a grid voltage,
Each thyristor in the thyristor module is conducted according to a trigger signal received by a corresponding gate electrode and voltage signals at two ends of each thyristor, so that an A phase, a B phase and a C phase in a power grid are respectively connected with a corresponding filter capacitor in the filter capacitor module through the conducted thyristors.
4. The apparatus of claim 1, wherein the contactor module is turned on after the grid voltage signal returns to normal such that the grid and the filter capacitor module are connected by the turned-on contactor module and the thyristor module is turned off.
5. The apparatus of claim 1, wherein the trigger module sends the trigger signal again to the thyristor module in response to the filter capacitor cut-out control signal sent by the converter controller, the thyristor module being turned on in response to the trigger signal, the contactor module being turned off in response to the filter capacitor cut-out control signal, the filter capacitor module being cut out from the power grid over a preset time.
6. The apparatus of claim 1 or 5, wherein the thyristor module is responsive to the trigger signal disappearing, the thyristors in the thyristor module being all turned off according to the filtered current zero crossing and the voltage signal from the trigger module.
7. A filter capacitor operation control method performed by a filter capacitor operation control device of a current transformer, the current transformer including a filter capacitor module, wherein the filter capacitor operation control device includes a current transformer controller, a trigger module, a thyristor module, and a contactor module, the method being used in a low voltage ride through condition, comprising:
detecting a voltage signal of the power grid by a trigger module;
The converter controller sends a filter capacitor input control signal to the trigger module and the contactor module;
The triggering module sends a triggering signal to the thyristor module according to the detected voltage signal and the filter capacitor input control signal;
Responding to the trigger signal, and conducting the thyristors in the thyristor module according to the detected voltage signal by the thyristor module so that the power grid is connected with the filter capacitor module in the converter through the conducted thyristors;
In response to the filter capacitor input control signal, the contactor module connects the power grid with the filter capacitor module,
When the power grid is connected with the filter capacitor module through the conducted contactor module, the thyristor module is bypassed;
When the amplitude of the power grid voltage is detected to be reduced to a low voltage standard, if the power grid is connected with the filter capacitor module through the contactor module, responding to a filter capacitor input control signal, and conducting a thyristor in the thyristor module so that the power grid is connected with the filter capacitor module through the conducting thyristor module; and if the power grid is not connected with the filter capacitor module through the contactor module but connected with the filter capacitor module through the thyristor module, waiting for the power grid voltage signal to return to normal.
8. The method of claim 7, wherein the thyristor module comprises 6 thyristors and the filter capacitor module comprises a three-phase filter capacitor,
The control valve of the grid A phase is formed by the first thyristor and the second thyristor and used for controlling the connection of the first filter capacitor and the grid A phase, the control valve of the grid B phase is formed by the third thyristor and the fourth thyristor and used for controlling the connection of the second filter capacitor and the grid B phase, and the control valve of the grid C phase is formed by the fifth thyristor and the sixth thyristor and used for controlling the connection of the third filter capacitor and the grid C phase.
9. The method of claim 8, wherein the step of connecting the power grid to the filter capacitor module by the thyristor module based on the detected voltage signal comprises:
A trigger signal is sent by the trigger module to the gate of each of the 6 thyristors based on the magnitude and phase of the grid voltage,
And conducting each thyristor in the thyristor module according to the trigger signal received by the corresponding gate electrode and the voltage signals at two ends of each thyristor, so that the A phase, the B phase and the C phase in the power grid are respectively connected with the corresponding filter capacitor in the filter capacitor module through the conducted thyristors.
10. The method of claim 7, wherein the method further comprises:
in response to a filter capacitor cut-out control signal sent by the converter controller, sending a trigger signal to the thyristor module again by the trigger module, and conducting the thyristor module according to the trigger signal;
And responding to the filter capacitor cut-out control signal, disconnecting the contactor module, and cutting out the filter capacitor module from the power grid after a preset time.
11. The method of claim 7 or 10, wherein the method further comprises:
in response to the trigger signal disappearing, all thyristors in the thyristor module are turned off by the thyristor module according to the filtered current zero crossing point and the voltage signal from the trigger module.
12. A filter capacitor operation control method performed by a filter capacitor operation control device of a current transformer, the current transformer including a filter capacitor module, wherein the filter capacitor operation control device includes a current transformer controller, a trigger module, a thyristor module, and a contactor module, the method being used in a low voltage ride through condition, comprising:
detecting a voltage signal of the power grid by a trigger module;
when the detected voltage signal meets the low voltage standard, determining by the trigger module whether the filter capacitor module has been put into the power grid by the contactor module;
When it is determined that the filter capacitor module is put into the power grid via the contactor module, the thyristors in the thyristor module are turned on in response to the filter capacitor put control signal, so that the power grid and the filter capacitor module are connected by the turned-on thyristor module,
Wherein when the detected voltage signal meets the low voltage criterion and it is determined that the filter capacitor module is not put into the power grid via the contactor module, it is determined by the triggering module whether the filter capacitor module is put into the power grid via the thyristor module,
When the filter capacitor module is determined to be put into the power grid through the thyristor module, the voltage signal is waited to be recovered to be normal, and when the filter capacitor module is determined not to be put into the power grid through the thyristor module, the converter is closed.
13. The method of claim 12, wherein the method further comprises:
and after the voltage signal of the power grid is recovered to be normal, the contactor module is conducted, so that the power grid is connected with the filter capacitor module through the conducted contactor module, and the thyristor module is disconnected.
14. A computer apparatus comprising a readable medium storing a computer program, characterized in that the computer program comprises instructions for performing the method of any one of claims 7 to 13.
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