CN112952889B - Optimizing method and device for virtual power grid self-adaptive control strategy and terminal equipment - Google Patents
Optimizing method and device for virtual power grid self-adaptive control strategy and terminal equipment Download PDFInfo
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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
- H02J3/36—Arrangements for transfer of electric power between ac networks via a high-tension dc link
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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
- H02J3/001—Methods to deal with contingencies, e.g. abnormalities, faults or failures
- H02J3/00125—Transmission line or load transient problems, e.g. overvoltage, resonance or self-excitation of inductive loads
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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
- H02J3/36—Arrangements for transfer of electric power between ac networks via a high-tension dc link
- H02J2003/365—Reducing harmonics or oscillations in HVDC
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- 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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- 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
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/60—Arrangements for transfer of electric power between AC networks or generators via a high voltage DC link [HVCD]
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Abstract
The invention relates to a method, a device and a terminal device for optimizing a self-adaptive control strategy of a virtual power grid, which are applied to a flexible direct current power transmission system, wherein the method, the device and the terminal device are used for controlling the self-adaptive control strategy of the virtual power grid to switch among a first link, a second link and a third link according to the actual alternating voltage of an alternating current side of a flexible direct current converter of the flexible direct current power transmission system, so that the risk of resonance of the flexible direct current power transmission system can be reduced, the flexible direct current power transmission system can obtain better dynamic characteristics in the moment of fault and in the fault recovery process, the damage to loads (devices or equipment) caused by overstress generated by the flexible direct current power transmission system is avoided, and the safety of direct current fault ride-through of the flexible direct current power transmission system is improved; the problem that dynamic characteristics are poor in an alternating current fault recovery process when the existing virtual power grid self-adaptive controller is adopted to inhibit high-frequency resonance of a flexible direct current transmission line is solved.
Description
Technical Field
The present invention relates to the field of electric power technologies, and in particular, to a method, an apparatus, and a terminal device for optimizing a virtual power grid adaptive control strategy.
Background
Flexible direct current transmission is a trend of future power system development, and several key technical problems to be solved by applying flexible direct current transmission are solved, wherein one of the key technical problems is to inhibit high-frequency resonance between a flexible direct current system and an alternating current system, and the high-frequency resonance is mainly caused by that a flexible direct current converter of the flexible direct current transmission presents negative impedance to amplify harmonic waves of a power transmission system, and is also caused by that the flexible direct current converter is not matched with the impedance of the alternating current system. The high frequency resonance is mainly related to control link delay and feedforward strategies of flexible direct current transmission. For the high-frequency resonance, the main solution in the flexible direct current transmission engineering is to reasonably configure a filter strategy in the feedforward link of the flexible direct current station inner loop controller, namely a virtual power grid self-adaptive controller strategy.
When the virtual power grid self-adaptive controller strategy adopts low-pass filtering and nonlinear filtering to inhibit high-frequency resonance of flexible direct-current transmission, the technical problem of deteriorating dynamic characteristics of a power system exists. For example, the Chinese intellectual property office discloses a flexible direct current high-frequency resonance method, a system and equipment with the bulletin number of CN111799833A in 10 and 20 in 2020, and the input quantity and the output quantity of the virtual power grid self-adaptive controller are completely isolated physically under the normal working condition, so that the harmonic wave of the actual electric quantity can not be reflected on the virtual electric quantity, and the effect of inhibiting the harmonic wave is achieved. When the effective value of the actual alternating voltage which is actually input is reduced from a normal value to a value which meets the preset condition, the virtual electric quantity is enabled to be completely equal to the actual electric quantity, so that the actual electric quantity is completely tracked in real time, and the dynamic characteristic of the power system at the moment of fault is improved; after the complete tracking is performed for a period of time, if the effective value of the actual alternating voltage is smaller than a preset threshold value, the self-adaptive tracking is performed until the actual electric quantity is recovered to a stable value, so that the technical problem is solved. The filtering process of the virtual power grid self-adaptive controller strategy is divided into three links of no response to small change of actual electric quantity under normal working conditions, complete tracking of actual electric quantity at the moment of failure and self-adaptive tracking of actual electric quantity during failure and recovery, when the flexible direct-current power transmission adopts the current virtual power grid self-adaptive control strategy, the three links are required to be smoothly switched, and the problem of poor dynamic characteristics can exist in the alternating-current failure recovery process.
Therefore, in the flexible direct current power transmission system, how to ensure that the virtual power grid filter is smoothly switched among three links in the virtual power grid self-adaptive controller strategy so as to obtain a good resonance suppression effect and good dynamic characteristics (starting of the power transmission system, alternating current fault moment and fault recovery process) of the power transmission system becomes a problem to be solved in the field.
Disclosure of Invention
The embodiment of the invention provides a method, a device and terminal equipment for optimizing a virtual power grid self-adaptive control strategy, which are used for solving the technical problem that the dynamic characteristic is poor in the alternating current fault recovery process when the existing virtual power grid self-adaptive controller is adopted to inhibit high-frequency resonance of a flexible direct current transmission line.
In order to achieve the above object, the embodiment of the present invention provides the following technical solutions:
the optimizing method of the self-adaptive control strategy of the virtual power grid is applied to a flexible direct current transmission system and is suitable for installing the self-adaptive controller of the virtual power grid in the feedforward link of the current inner loop controller in the flexible direct current transmission system in advance, and the optimizing method comprises the following steps:
s10, when a flexible direct current transmission system starts a virtual power grid self-adaptive control strategy, controlling the output of a virtual power grid self-adaptive controller to be equal to the input of the virtual power grid self-adaptive controller and to be unchanged, namely, enabling the virtual power grid self-adaptive control strategy to enter a first link, and acquiring a first actual alternating voltage of an alternating current side of a flexible direct current converter in the flexible direct current transmission system;
s20, if the effective value of the first actual alternating voltage is larger than a first preset value, the output of the virtual power grid self-adaptive controller is kept unchanged, namely the virtual power grid self-adaptive control strategy is always in the first link;
s30, if the effective value of the first actual alternating voltage is not greater than a first preset value, controlling the output of the virtual power grid self-adaptive controller to be equal to the input of the virtual power grid self-adaptive controller, enabling the virtual power grid self-adaptive control strategy to enter a second link, and obtaining the tracking time when the output of the virtual power grid self-adaptive controller is completely equal to the input of the virtual power grid self-adaptive controller;
s40, if the tracking time reaches a time set value, controlling a virtual power grid self-adaptive control strategy to enter a third link, and simultaneously obtaining a second actual alternating voltage of an alternating side of the flexible direct current converter in the flexible direct current transmission system;
s50, if the effective value of the second actual alternating voltage is larger than the first preset value, controlling the virtual power grid self-adaptive control strategy to exit the third link, and simultaneously obtaining a voltage difference value between the output of the virtual power grid self-adaptive controller and the input of the virtual power grid self-adaptive controller;
s60, if the voltage difference value is larger than a second preset value, controlling the output of the virtual power grid self-adaptive controller to be equal to the input of the virtual power grid self-adaptive controller, and switching the virtual power grid self-adaptive control strategy from the third link to the first link;
s70, if the voltage difference value is not larger than a second preset value, controlling the virtual power grid self-adaptive control strategy to be directly switched from the third link to the first link;
the first link is that the virtual power grid self-adaptive control strategy is in a state of 'normal working condition does not respond to the tiny change of the actual electric quantity'; the second link is that the self-adaptive control strategy of the virtual power grid is in a state of 'completely tracking the actual electric quantity at the moment of failure'; and the third link is that the self-adaptive control strategy of the virtual power grid is in a state of 'self-adaptively tracking the actual electric quantity during fault and recovery'.
Preferably, in step S20, the first preset value ranges from 0.7pu to 0.9pu.
Preferably, in step S40, the time set value ranges from 2ms to 15ms.
Preferably, in step S60, the second preset value ranges from 0.005pu to 0.02pu.
Preferably, before step S10, the optimization method of the virtual grid adaptive control strategy further includes: the flexible direct current transmission system does not receive the converter unlocking signal, and a virtual power grid self-adaptive control strategy is not required to be started; and receiving an inverter unlocking signal at the flexible direct current transmission system, and starting a virtual power grid self-adaptive control strategy.
The invention also provides an optimizing device of the virtual power grid self-adaptive control strategy, which is applied to the flexible direct current transmission system and is suitable for installing the virtual power grid self-adaptive controller in the feedforward link of the current inner loop controller in the flexible direct current transmission system in advance, and the optimizing device comprises a voltage acquisition module, a first execution module, a second execution module, a third execution module, a fourth execution module, a fifth execution module and a sixth execution module;
the voltage acquisition module is used for starting a virtual power grid self-adaptive control strategy according to the flexible direct current power transmission system, controlling the output of the virtual power grid self-adaptive controller to be equal to the input of the virtual power grid self-adaptive controller and keeping unchanged, namely, the virtual power grid self-adaptive control strategy enters a first link, and acquiring a first actual alternating voltage of an alternating side of the flexible direct current converter in the flexible direct current power transmission system;
the first execution module is configured to keep output of the virtual power grid adaptive controller unchanged according to that an effective value of the first actual ac voltage is greater than a first preset value, that is, the virtual power grid adaptive control strategy is always in the first link;
the second execution module is configured to control, according to the effective value of the first actual ac voltage not greater than a first preset value, the output of the virtual power grid adaptive controller to be equal to the input of the virtual power grid adaptive controller, and the virtual power grid adaptive control strategy enters a second link to obtain a tracking time when the output of the virtual power grid adaptive controller is completely equal to the input of the virtual power grid adaptive controller;
the third execution module is used for controlling the virtual power grid self-adaptive control strategy to enter a third link according to the tracking time reaching a time set value, and simultaneously obtaining a second actual alternating voltage of the alternating side of the flexible direct current converter in the flexible direct current transmission system;
the fourth execution module is configured to control the virtual power grid adaptive control strategy to exit the third link according to the effective value of the second actual ac voltage being greater than the first preset value, and simultaneously obtain a voltage difference between the output of the virtual power grid adaptive controller and the input of the virtual power grid adaptive controller;
the fifth execution module is configured to control, according to the voltage difference value being greater than a second preset value, an output of the virtual power grid adaptive controller to be equal to an input of the virtual power grid adaptive controller, and the virtual power grid adaptive control strategy is switched from the third link to the first link;
the sixth execution module is configured to control the virtual power grid adaptive control strategy to directly switch from the third link to the first link according to the voltage difference value not greater than a second preset value;
the first link is that the virtual power grid self-adaptive control strategy is in a state of 'normal working condition does not respond to the tiny change of the actual electric quantity'; the second link is that the self-adaptive control strategy of the virtual power grid is in a state of 'completely tracking the actual electric quantity at the moment of failure'; and the third link is that the self-adaptive control strategy of the virtual power grid is in a state of 'self-adaptively tracking the actual electric quantity during fault and recovery'.
Preferably, the first preset value ranges from 0.7pu to 0.9pu.
Preferably, the time set point ranges from 2ms to 15ms.
Preferably, the second preset value ranges from 0.005pu to 0.02pu.
Preferably, the optimizing device of the virtual power grid adaptive control strategy further comprises: the starting determining module is used for not receiving the converter unlocking signal according to the flexible direct current transmission system, and does not need to start the virtual power grid self-adaptive control strategy; or receiving the converter unlocking signal according to the flexible direct current transmission system, and starting the virtual power grid self-adaptive control strategy
The invention also provides a computer readable storage medium for storing computer instructions that, when run on a computer, cause the computer to perform the method of optimizing a virtual grid adaptive control strategy described above.
The invention also provides a terminal device, which comprises a processor and a memory;
the memory is used for storing program codes and transmitting the program codes to the processor;
and the processor is used for executing the optimization method of the virtual power grid self-adaptive control strategy according to the instructions in the program codes.
From the above technical solutions, the embodiment of the present invention has the following advantages: according to the optimization method, the device and the terminal equipment of the virtual power grid self-adaptive control strategy, the virtual power grid self-adaptive control strategy is controlled to switch among the first link, the second link and the third link according to the actual alternating voltage of the alternating current side of the flexible direct current converter of the flexible direct current power transmission system, so that the risk of resonance of the flexible direct current power transmission system can be reduced, the flexible direct current power transmission system can obtain better dynamic characteristics in the fault moment and the fault recovery process, damage to loads (devices or equipment) caused by overstresses generated by the flexible direct current power transmission system is avoided, and the safety of direct current fault ride through of the flexible direct current power transmission system is improved; the technical problem that dynamic characteristics are poor in an alternating current fault recovery process when the existing virtual power grid self-adaptive controller is adopted to inhibit high-frequency resonance of a flexible direct current transmission line is solved.
Drawings
In order to more clearly illustrate the embodiments of the invention or the technical solutions of the prior art, the drawings which are used in the description of the embodiments or the prior art will be briefly described, it being obvious that the drawings in the description below are only some embodiments of the invention, and that other drawings can be obtained from these drawings without inventive faculty for a person skilled in the art.
Fig. 1 is a flowchart of steps of a method for optimizing a virtual grid adaptive control strategy according to an embodiment of the present invention.
Fig. 2 is a schematic diagram of tracking of a virtual grid adaptive controller in the optimization method of the virtual grid adaptive control strategy according to the embodiment of the present invention.
Fig. 3 is a schematic structural diagram of positive sequence inner loop control of the flexible direct current transmission system of the virtual power grid adaptive control strategy in the optimization method of the virtual power grid adaptive control strategy according to the embodiment of the invention.
Fig. 4 is a schematic structural diagram of a negative sequence inner loop control of a flexible direct current transmission system of a virtual power grid adaptive control strategy in an optimization method of the virtual power grid adaptive control strategy according to an embodiment of the present invention.
Fig. 5 is a frame diagram of an optimizing device of a virtual grid adaptive control strategy according to an embodiment of the present invention.
Detailed Description
In order to make the objects, features and advantages of the present invention more comprehensible, the technical solutions in the embodiments of the present invention are described in detail below with reference to the accompanying drawings, and it is apparent that the embodiments described below are only some embodiments of the present invention, but not all embodiments of the present invention. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.
The vector control based on direct current control is widely adopted in the engineering at present, and consists of an outer ring control strategy and an inner ring control strategy, wherein the vector control mainly is based on a flexible direct current mathematical model under a dq rotating coordinate system, and the d-axis component and the q-axis component of a valve side voltage fundamental wave of a valve group are respectively subjected to decoupling control, so that the exchange of power between an alternating current system and a direct current system is realized, the current can be effectively limited, and meanwhile, the vector control has good response characteristics. The structure of the inner loop controller is shown in fig. 3 and 4, and the flexible direct current inner loop control link receives the reference value I of active and reactive current from the outer loop control dref And I qref The control of the dq component of the alternating-current side voltage of the valve bank is realized by fast tracking the reference current through a proportional integral link, and the amplitude and the phase of the alternating-current side voltage of the valve bank can be changed by changing Vd and Vq components, so that the exchange of power between alternating-current and direct-current systems is realized. The current inner loop control adopts double dq decoupling control (positive sequence and negative sequence); the positive sequence inner loop controller tracks the active and reactive current reference value, and the negative sequence inner loop is used as asymmetric fault controlThe main function of the system is to control the negative sequence current component generated under the asymmetric working condition of the power grid to be zero so as to prevent the valve bank from overcurrent and the power module capacitor from overvoltage. The virtual power grid self-adaptive controller is mainly used for a positive and negative sequence inner loop voltage feedforward link. The angle of the positive sequence coordinate transformation is the angle of the phase-locked loop; the angle of the negative sequence coordinate transformation is the angle of the phase-locked loop multiplied by-1.
The embodiment of the application provides a virtual power grid self-adaptive control strategy optimization method, device and terminal equipment, which are used for solving the technical problem that the dynamic characteristics are poor in the alternating current fault recovery process when the existing virtual power grid self-adaptive controller is adopted to inhibit high-frequency resonance of a flexible direct current transmission line.
Embodiment one:
fig. 1 is a flowchart illustrating steps of an optimization method of a virtual power grid adaptive control strategy according to an embodiment of the present invention, and fig. 2 is a schematic tracking diagram of a virtual power grid adaptive controller in the optimization method of a virtual power grid adaptive control strategy according to an embodiment of the present invention.
As shown in fig. 1 and fig. 2, an embodiment of the present invention provides an optimization method of a virtual power grid adaptive control strategy, which is applied to a flexible direct current transmission system and is suitable for installing a virtual power grid adaptive controller in advance in a feedforward link of a current inner loop controller in the flexible direct current transmission system, and the optimization method includes the following steps:
s10, when the flexible direct current transmission system starts a virtual power grid self-adaptive control strategy, controlling the output of a virtual power grid self-adaptive controller to be equal to the input of the virtual power grid self-adaptive controller and keeping unchanged, namely, enabling the virtual power grid self-adaptive control strategy to enter a first link, and acquiring a first actual alternating voltage of an alternating side of a flexible direct current converter in the flexible direct current transmission system;
s20, if the effective value of the first actual alternating voltage is larger than a first preset value, the output of the virtual power grid self-adaptive controller is kept unchanged, namely the virtual power grid self-adaptive control strategy is always in a first link;
s30, if the effective value of the first actual alternating voltage is not greater than a first preset value, controlling the output of the virtual power grid adaptive controller to be equal to the input of the virtual power grid adaptive controller, enabling the virtual power grid adaptive control strategy to enter a second link, and obtaining the tracking time when the output of the virtual power grid adaptive controller is completely equal to the input of the virtual power grid adaptive controller;
s40, if the tracking time reaches a time set value, controlling a virtual power grid self-adaptive control strategy to enter a third link, and simultaneously acquiring a second actual alternating voltage of an alternating side of the flexible direct current converter in the flexible direct current power transmission system;
s50, if the effective value of the second actual alternating voltage is larger than the first preset value, controlling the virtual power grid self-adaptive control strategy to exit the third link, and simultaneously obtaining a voltage difference value between the output of the virtual power grid self-adaptive controller and the input of the virtual power grid self-adaptive controller;
s60, if the voltage difference value is larger than a second preset value, controlling the output of the virtual power grid self-adaptive controller to be equal to the input of the virtual power grid self-adaptive controller, and switching the virtual power grid self-adaptive control strategy from a third link to a first link;
s70, if the voltage difference value is not greater than a second preset value, controlling the virtual power grid self-adaptive control strategy to be directly switched from the third link to the first link;
the first link is that the self-adaptive control strategy of the virtual power grid is in a state of 'normal working condition does not respond to the tiny change of the actual electric quantity'; the second link is that the self-adaptive control strategy of the virtual power grid is in a state of 'completely tracking the actual electric quantity at the moment of failure'; and the third link is that the self-adaptive control strategy of the virtual power grid is in a state of 'self-adaptively tracking the actual electric quantity during fault and recovery'.
In the embodiment of the present invention, before step S10, the method for optimizing the adaptive control strategy of the virtual grid further includes: the flexible direct current transmission system does not receive the converter unlocking signal, and a virtual power grid self-adaptive control strategy is not required to be started; and receiving an inverter unlocking signal at the flexible direct current transmission system, and starting a virtual power grid self-adaptive control strategy.
It should be noted that, before unlocking, the converter of the flexible direct current transmission system has no resonance problem, the flexible direct current transmission system does not need to start the virtual power grid self-adaptive control strategy, and only after unlocking, the converter of the flexible direct current transmission system needs to start the virtual power grid self-adaptive control strategy to inhibit the high-frequency resonance of the flexible direct current transmission line.
In step S10 of the embodiment of the present invention, after a virtual power grid adaptive control strategy is started according to a flexible direct current power transmission system, an output of a virtual power grid adaptive controller of the flexible direct current power transmission system is controlled to be equal to an input of the virtual power grid adaptive controller at a moment of unlocking the converter, and an output of the virtual power grid adaptive controller (the virtual power grid adaptive controller) is kept unchanged, and the virtual power grid adaptive control strategy formally enters a first link of "normal working conditions do not respond to a small change of an actual electric quantity", and a first actual ac voltage on an ac side of the flexible direct current converter in the flexible direct current power transmission system is also obtained.
It should be noted that, the content of obtaining the first actual ac voltage on the ac side of the flexible dc converter in the flexible dc power transmission system is described in detail in patent document with publication number CN111799833a, which is a flexible dc high-frequency resonance method, system and apparatus, and is not described in any way in this embodiment.
In step S20 and step S30 of the embodiment of the present invention, the time for determining and acquiring the effective value of the first actual ac voltage is described in detail in patent literature of a flexible dc high-frequency resonance method, system and device with the publication number CN111799833a, which is not described in detail in this embodiment.
The range of the first preset value is 0.7pu to 0.9pu.
In step S40 of the embodiment of the present invention, mainly, according to whether the tracking time reaches the set time setting value, the virtual power grid adaptive control strategy is controlled to switch from the second link to the third link, and the second actual ac voltage of the flexible dc power transmission system at this time is obtained.
The time set value ranges from 2ms to 15ms.
In step S50 of the embodiment of the present invention, the effective value of the second actual ac voltage is mainly determined, whether the virtual grid adaptive control strategy exits the third link is controlled, and the voltage difference between the output of the virtual grid adaptive controller and the input thereof at this time is obtained.
In step S60 and step S70 of the embodiment of the present invention, whether the virtual power grid adaptive control strategy is directly switched from the third link to the first link is controlled mainly according to whether the voltage difference value meets the second preset value.
The second preset value ranges from 0.005pu to 0.02pu.
According to the optimization method of the virtual power grid self-adaptive control strategy, which is provided by the invention, the virtual power grid self-adaptive control strategy is controlled to switch among the first link, the second link and the third link according to the actual alternating voltage of the alternating current side of the flexible direct current converter of the flexible direct current power transmission system, so that the risk of resonance of the flexible direct current power transmission system can be reduced, the flexible direct current power transmission system can obtain better dynamic characteristics in the fault moment and the fault recovery process, the damage of the load (device or equipment) caused by the overstress generated by the flexible direct current power transmission system is avoided, and the safety of the direct current fault ride-through of the flexible direct current power transmission system is improved; the technical problem that dynamic characteristics are poor in an alternating current fault recovery process when the existing virtual power grid self-adaptive controller is adopted to inhibit high-frequency resonance of a flexible direct current transmission line is solved.
In the embodiment of the invention, the optimization method of the virtual power grid self-adaptive control strategy mainly comprises the steps of starting the virtual power grid self-adaptive control strategy for the flexible direct current power transmission system, controlling the link switching of the virtual power grid self-adaptive control strategy between a first link and a third link in the alternating current fault recovery process, and avoiding the bad dynamic characteristics of the virtual power grid self-adaptive control strategy in the link switching process, thereby damaging the load connected with the flexible direct current power transmission system.
Embodiment two:
fig. 5 is a frame diagram of an optimizing device of a virtual grid adaptive control strategy according to an embodiment of the present invention.
As shown in fig. 5, the embodiment of the present invention further provides an optimizing device of a virtual grid adaptive control strategy, which is applied to a flexible dc power transmission system and is suitable for installing a virtual grid adaptive controller in advance in a feedforward link of a current inner loop controller in the flexible dc power transmission system, where the optimizing device includes a voltage acquisition module 10, a first execution module 20, a second execution module 30, a third execution module 40, a fourth execution module 50, a fifth execution module 60, and a sixth execution module 70;
the voltage acquisition module 10 is configured to start a virtual power grid adaptive control strategy according to the flexible direct current power transmission system, control the output of the virtual power grid adaptive controller to be equal to the input of the virtual power grid adaptive controller and to remain unchanged, that is, the virtual power grid adaptive control strategy enters a first link, and acquire a first actual alternating voltage of an alternating side of the flexible direct current converter in the flexible direct current power transmission system;
the first execution module 20 is configured to keep the output of the virtual power grid adaptive controller unchanged according to the fact that the effective value of the first actual ac voltage is greater than a first preset value, that is, the virtual power grid adaptive control strategy is always in the first link;
the second execution module 30 is configured to control, according to the effective value of the first actual ac voltage not greater than the first preset value, the output of the virtual power grid adaptive controller to be equal to the input of the virtual power grid adaptive controller, the virtual power grid adaptive control strategy entering a second link, and obtaining a tracking time when the output of the virtual power grid adaptive controller is completely equal to the input of the virtual power grid adaptive controller;
the third execution module 40 is configured to control the virtual power grid adaptive control strategy to enter a third link according to the tracking time reaching the time set value, and obtain a second actual ac voltage on the ac side of the flexible dc converter in the flexible dc power transmission system;
the fourth execution module 50 is configured to control the virtual power grid adaptive control strategy to exit the third link according to the effective value of the second actual ac voltage being greater than the first preset value, and obtain a voltage difference between the output of the virtual power grid adaptive controller and the input of the virtual power grid adaptive controller;
the fifth execution module 60 is configured to control, according to the voltage difference being greater than the second preset value, the output of the virtual grid adaptive controller to be equal to the input of the virtual grid adaptive controller, and the virtual grid adaptive control strategy is switched from the third link to the first link;
the sixth execution module 70 is configured to control the virtual power grid adaptive control strategy to directly switch from the third link to the first link according to the voltage difference value being not greater than the second preset value;
the first link is that the self-adaptive control strategy of the virtual power grid is in a state of 'normal working condition does not respond to the tiny change of the actual electric quantity'; the second link is that the self-adaptive control strategy of the virtual power grid is in a state of 'completely tracking the actual electric quantity at the moment of failure'; and the third link is that the self-adaptive control strategy of the virtual power grid is in a state of 'self-adaptively tracking the actual electric quantity during fault and recovery'.
In the embodiment of the invention, the range of the first preset value is 0.7 pu-0.9 pu; the range of the time set value is 2 ms-15 ms; the second preset value ranges from 0.005pu to 0.02pu.
In an embodiment of the present invention, the optimizing device of the adaptive control strategy of the virtual power grid further includes: the starting determining module is used for not receiving the converter unlocking signal according to the flexible direct current transmission system, and does not need to start the virtual power grid self-adaptive control strategy; or receiving an inverter unlocking signal according to the flexible direct current transmission system, and starting a virtual power grid self-adaptive control strategy.
It should be noted that, the modules in the apparatus of the second embodiment correspond to the steps in the method of the second embodiment, and the steps in the method of the second embodiment are described in detail in the first embodiment, and the details of the modules in the apparatus are not described in detail in the second embodiment.
Embodiment III:
the embodiment of the invention provides a computer readable storage medium, which is used for storing computer instructions, and when the computer instructions run on a computer, the computer is caused to execute the optimization method of the virtual power grid adaptive control strategy.
Embodiment four:
the embodiment of the invention provides terminal equipment, which comprises a processor and a memory;
a memory for storing program code and transmitting the program code to the processor;
and the processor is used for executing the optimization method of the virtual power grid adaptive control strategy according to the instructions in the program codes.
It should be noted that the processor is configured to execute the steps in the above-described embodiment of the method for optimizing a virtual grid adaptive control strategy according to instructions in the program code. In the alternative, the processor, when executing the computer program, performs the functions of the modules/units in the system/apparatus embodiments described above.
For example, a computer program may be split into one or more modules/units, which are stored in a memory and executed by a processor to complete the present application. One or more of the modules/units may be a series of computer program instruction segments capable of performing specific functions for describing the execution of the computer program in the terminal device.
The terminal device may be a computing device such as a desktop computer, a notebook computer, a palm computer, a cloud server, etc. The terminal device may include, but is not limited to, a processor, a memory. It will be appreciated by those skilled in the art that the terminal device is not limited and may include more or less components than those illustrated, or may be combined with certain components, or different components, e.g., the terminal device may also include input and output devices, network access devices, buses, etc.
The processor may be a central processing unit (Central Processing Unit, CPU), other general purpose processors, digital signal processors (Digital Signal Processor, DSP), application specific integrated circuits (Application Specific Integrated Circuit, ASIC), off-the-shelf programmable gate arrays (Field-Programmable Gate Array, FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, or the like. A general purpose processor may be a microprocessor or the processor may be any conventional processor or the like.
The memory may be an internal storage unit of the terminal device, such as a hard disk or a memory of the terminal device. The memory may also be an external storage device of the terminal device, such as a plug-in hard disk provided on the terminal device, a Smart Media Card (SMC), a Secure Digital (SD) Card, a Flash memory Card (Flash Card), or the like. Further, the memory may also include both an internal storage unit of the terminal device and an external storage device. The memory is used for storing computer programs and other programs and data required by the terminal device. The memory may also be used to temporarily store data that has been output or is to be output.
It will be clear to those skilled in the art that, for convenience and brevity of description, specific working procedures of the above-described systems, apparatuses and units may refer to corresponding procedures in the foregoing method embodiments, which are not repeated herein.
In the several embodiments provided in this application, it should be understood that the disclosed systems, apparatuses, and methods may be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative, e.g., the division of the units is merely a logical function division, and there may be additional divisions when actually implemented, e.g., multiple units or components may be combined or integrated into another system, or some features may be omitted or not performed. Alternatively, the coupling or direct coupling or communication connection shown or discussed with each other may be an indirect coupling or communication connection via some interfaces, devices or units, which may be in electrical, mechanical or other form.
The units described as separate units may or may not be physically separate, and units shown as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.
In addition, each functional unit in the embodiments of the present invention may be integrated in one processing unit, or each unit may exist alone physically, or two or more units may be integrated in one unit. The integrated units may be implemented in hardware or in software functional units.
The integrated units, if implemented in the form of software functional units and sold or used as stand-alone products, may be stored in a computer readable storage medium. Based on such understanding, the technical solution of the present invention may be embodied essentially or in part or all of the technical solution or in part in the form of a software product stored in a storage medium, including instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method according to the embodiments of the present invention. And the aforementioned storage medium includes: a U-disk, a removable hard disk, a Read-Only Memory (ROM), a random access Memory (RAM, random Access Memory), a magnetic disk, or an optical disk, or other various media capable of storing program codes.
The above embodiments are only for illustrating the technical solution of the present invention, and not for limiting the same; although the invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit and scope of the technical solutions of the embodiments of the present invention.
Claims (9)
1. The optimizing method of the self-adaptive control strategy of the virtual power grid is applied to a flexible direct current transmission system and is suitable for installing the self-adaptive controller of the virtual power grid in the feedforward link of the current inner loop controller in the flexible direct current transmission system in advance, and the optimizing method comprises the following steps:
s10, when a flexible direct current power transmission system starts a virtual power grid self-adaptive control strategy, controlling the output of a virtual power grid self-adaptive controller to be equal to the input of the virtual power grid self-adaptive controller and to be unchanged, namely, enabling the virtual power grid self-adaptive control strategy to enter a first link, and acquiring a first actual alternating voltage of an alternating current side of a flexible direct current converter in the flexible direct current power transmission system;
s20, if the effective value of the first actual alternating voltage is larger than a first preset value, the output of the virtual power grid self-adaptive controller is kept unchanged, namely the virtual power grid self-adaptive control strategy is always in the first link;
s30, if the effective value of the first actual alternating voltage is not greater than a first preset value, controlling the output of the virtual power grid self-adaptive controller to be equal to the input of the virtual power grid self-adaptive controller, enabling the virtual power grid self-adaptive control strategy to enter a second link, and obtaining the tracking time when the output of the virtual power grid self-adaptive controller is completely equal to the input of the virtual power grid self-adaptive controller;
it is characterized in that the method comprises the steps of,
s40, if the tracking time reaches a time set value, controlling a virtual power grid self-adaptive control strategy to enter a third link, and simultaneously obtaining a second actual alternating voltage of an alternating side of the flexible direct current converter in the flexible direct current transmission system;
s50, if the effective value of the second actual alternating voltage is larger than the first preset value, controlling the virtual power grid self-adaptive control strategy to exit the third link, and simultaneously obtaining a voltage difference value between the output of the virtual power grid self-adaptive controller and the input of the virtual power grid self-adaptive controller;
s60, if the voltage difference value is larger than a second preset value, controlling the output of the virtual power grid self-adaptive controller to be equal to the input of the virtual power grid self-adaptive controller, and switching the virtual power grid self-adaptive control strategy from the third link to the first link;
s70, if the voltage difference value is not larger than a second preset value, controlling the virtual power grid self-adaptive control strategy to be directly switched from the third link to the first link;
the first link is that the virtual power grid self-adaptive control strategy is in a state of 'normal working condition does not respond to the tiny change of the actual electric quantity'; the second link is that the self-adaptive control strategy of the virtual power grid is in a state of 'completely tracking the actual electric quantity at the moment of failure'; the third link is that the virtual power grid adaptive control strategy is in a state of 'self-adaptively tracking the actual electric quantity during fault and recovery', and in step S60, the second preset value ranges from 0.005pu to 0.02pu.
2. The method according to claim 1, wherein in step S20, the first preset value ranges from 0.7pu to 0.9pu.
3. The method according to claim 1, wherein in step S40, the time set value ranges from 2ms to 15ms.
4. The method for optimizing a virtual grid adaptive control strategy according to claim 1, further comprising, prior to step S10: the flexible direct current transmission system does not receive the converter unlocking signal, and a virtual power grid self-adaptive control strategy is not required to be started; and receiving an inverter unlocking signal at the flexible direct current transmission system, and starting a virtual power grid self-adaptive control strategy.
5. The optimizing device of the virtual power grid self-adaptive control strategy is applied to a flexible direct current transmission system and is suitable for installing a virtual power grid self-adaptive controller in a feedforward link of a current inner loop controller in the flexible direct current transmission system in advance, and is characterized by comprising a voltage acquisition module, a first execution module, a second execution module, a third execution module, a fourth execution module, a fifth execution module and a sixth execution module;
the voltage acquisition module is used for starting a virtual power grid self-adaptive control strategy according to the flexible direct current power transmission system, controlling the output of the virtual power grid self-adaptive controller to be equal to the input of the virtual power grid self-adaptive controller and keeping unchanged, namely, the virtual power grid self-adaptive control strategy enters a first link, and acquiring a first actual alternating voltage of an alternating side of the flexible direct current converter in the flexible direct current power transmission system;
the first execution module is configured to keep output of the virtual power grid adaptive controller unchanged according to that an effective value of the first actual ac voltage is greater than a first preset value, that is, the virtual power grid adaptive control strategy is always in the first link;
the second execution module is configured to control, according to the effective value of the first actual ac voltage not greater than a first preset value, the output of the virtual power grid adaptive controller to be equal to the input of the virtual power grid adaptive controller, and the virtual power grid adaptive control strategy enters a second link to obtain a tracking time when the output of the virtual power grid adaptive controller is completely equal to the input of the virtual power grid adaptive controller;
the third execution module is used for controlling the virtual power grid self-adaptive control strategy to enter a third link according to the tracking time reaching a time set value, and simultaneously obtaining a second actual alternating voltage of the alternating side of the flexible direct current converter in the flexible direct current transmission system;
the fourth execution module is configured to control the virtual power grid adaptive control strategy to exit the third link according to the effective value of the second actual ac voltage being greater than the first preset value, and simultaneously obtain a voltage difference between the output of the virtual power grid adaptive controller and the input of the virtual power grid adaptive controller;
the fifth execution module is configured to control, according to the voltage difference value being greater than a second preset value, an output of the virtual power grid adaptive controller to be equal to an input of the virtual power grid adaptive controller, and the virtual power grid adaptive control strategy is switched from the third link to the first link;
the sixth execution module is configured to control the virtual power grid adaptive control strategy to directly switch from the third link to the first link according to the voltage difference value not greater than a second preset value;
the first link is that the virtual power grid self-adaptive control strategy is in a state of 'normal working condition does not respond to the tiny change of the actual electric quantity'; the second link is that the self-adaptive control strategy of the virtual power grid is in a state of 'completely tracking the actual electric quantity at the moment of failure'; the third link is that the virtual power grid self-adaptive control strategy is in a state of 'self-adaptively tracking actual electric quantity during fault and recovery', and the range of the second preset value is 0.005 pu-0.02 pu.
6. The optimizing device of a virtual grid adaptive control strategy according to claim 5, wherein the range of the first preset value is 0.7pu to 0.9pu, and the range of the time set value is 2ms to 15ms.
7. The apparatus for optimizing a virtual grid adaptive control strategy according to claim 5, further comprising: the starting determining module is used for not receiving the converter unlocking signal according to the flexible direct current transmission system, and does not need to start the virtual power grid self-adaptive control strategy; or receiving an inverter unlocking signal according to the flexible direct current transmission system, and starting a virtual power grid self-adaptive control strategy.
8. A computer readable storage medium storing computer instructions which, when run on a computer, cause the computer to perform the method of optimizing a virtual grid adaptive control strategy according to any one of claims 1-4.
9. A terminal device comprising a processor and a memory;
the memory is used for storing program codes and transmitting the program codes to the processor;
the processor is configured to execute the optimization method of the virtual grid adaptive control strategy according to any one of claims 1-4 according to the instructions in the program code.
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Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111541263A (en) * | 2020-06-10 | 2020-08-14 | 南方电网科学研究院有限责任公司 | Harmonic control strategy evaluation method, system and equipment for flexible direct current transmission system |
| CN112103969A (en) * | 2020-08-25 | 2020-12-18 | 特变电工西安柔性输配电有限公司 | Flexible direct current transmission system oscillation suppression strategy based on PIR |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN104078974B (en) * | 2014-06-30 | 2016-05-04 | 湖南大学 | A kind of large-sized photovoltaic power station harmonic resonance specificity analysis and inhibition method |
| EP3709467A1 (en) * | 2019-03-13 | 2020-09-16 | Siemens Gamesa Renewable Energy A/S | Reduction of subsynchronous active power oscillations in grid forming pwm converters for wind turbine generators |
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| CN112103969A (en) * | 2020-08-25 | 2020-12-18 | 特变电工西安柔性输配电有限公司 | Flexible direct current transmission system oscillation suppression strategy based on PIR |
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