CN111030127B - Method and system for determining dynamic and static reactive power coordination control strategy of multi-direct-current feed-in system - Google Patents

Method and system for determining dynamic and static reactive power coordination control strategy of multi-direct-current feed-in system Download PDF

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CN111030127B
CN111030127B CN201911149278.4A CN201911149278A CN111030127B CN 111030127 B CN111030127 B CN 111030127B CN 201911149278 A CN201911149278 A CN 201911149278A CN 111030127 B CN111030127 B CN 111030127B
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current
generator
reactive power
power grid
direct
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CN111030127A (en
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申旭辉
潘晓杰
罗红梅
邵德军
马世英
唐晓骏
党杰
徐友平
岳宗祖
李晶
谢岩
高雯曼
张鑫
陈得治
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China Electric Power Research Institute Co Ltd CEPRI
Central China Grid Co Ltd
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China Electric Power Research Institute Co Ltd CEPRI
Central China Grid Co Ltd
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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
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J3/00—Circuit arrangements for ac mains or ac distribution networks
    • H02J3/18—Arrangements for adjusting, eliminating or compensating reactive power in networks
    • H02J3/1821—Arrangements for adjusting, eliminating or compensating reactive power in networks using shunt compensators
    • H02J3/1835—Arrangements for adjusting, eliminating or compensating reactive power in networks using shunt compensators with stepless control
    • H02J3/1864—Arrangements for adjusting, eliminating or compensating reactive power in networks using shunt compensators with stepless control wherein the stepless control of reactive power is obtained by at least one reactive element connected in series with a semiconductor switch
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J3/00—Circuit arrangements for ac mains or ac distribution networks
    • H02J3/18—Arrangements for adjusting, eliminating or compensating reactive power in networks
    • H02J3/1885—Arrangements for adjusting, eliminating or compensating reactive power in networks using rotating means, e.g. synchronous generators
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J3/00—Circuit arrangements for ac mains or ac distribution networks
    • H02J3/38—Arrangements for parallely feeding a single network by two or more generators, converters or transformers
    • H02J3/46—Controlling of the sharing of output between the generators, converters, or transformers
    • H02J3/50—Controlling the sharing of the out-of-phase component
    • 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

Abstract

The invention discloses a method and a system for determining a dynamic and static reactive power coordination control strategy of a multi-direct current feed-in system, wherein the method comprises the following steps: adjusting the generator terminal voltage of the generator, the reactive power output of the capacitor and the starting number of the generator to enable the overall operation voltage of the system to be a preset systemic overall operation voltage threshold value; performing N-1 fault checking on a direct current fed-in alternating current power grid in a current operation mode to obtain a first checking result; when the first check result indicates that the system is stable, reducing the terminal voltage of the generator, increasing the reactive power output of the capacitor, and maintaining the integral operation voltage of the system with the direct current fed into the alternating current power grid; performing N-1 fault checking to obtain a second checking result; and when the second check result indicates that the direct current input alternating current power grid is in a system unstable state, determining a dynamic and static reactive power coordination control strategy under the current overall system operation voltage according to the operation mode of the direct current input alternating current power grid in the system stable state.

Description

Method and system for determining dynamic and static reactive power coordination control strategy of multi-direct-current feed-in system
Technical Field
The invention relates to the technical field of power systems, in particular to a method and a system for determining a dynamic and static reactive power coordination control strategy of a multi-direct-current feed-in system.
Background
At present, with the rapid development of new energy in China, direct current transmission has the advantages of low line cost, small loss, large transmission capacity, high regulation speed and the like and becomes a main means of long-distance transmission, a voltage stabilization problem of a receiving-end alternating current power grid is increasingly serious due to direct current feed-in, the voltage stabilization problem is more prominent when a heavy load area is subjected to large disturbance due to continuous increase of dynamic load, and the safe and stable operation of the power grid faces more challenges.
The main reactive power adjusting means in the power grid comprises static elements such as a low-voltage compensation capacitor, a low-voltage reactor, a high-voltage reactor and the like, the capacitive reactive power output capacity of the capacitor is in a square-time relation with the voltage at the end of the capacitor, when the disturbed voltage of the power grid drops, the capacitor does not have the capacity of maintaining the steady-state reactive power output, and the larger the capacitive reactive power output is, the larger the loss capacity of response after disturbance is, so that the power grid voltage stability is not favorably maintained.
The receiving end power grid is provided with a large number of generator sets as important reactive power regulation equipment in the power grid, capacitive reactive power can be provided for the power grid and can be absorbed from the power grid under the regulation of an excitation system, the generator sets not only have the capacity of maintaining stable capacitive reactive power output in the dynamic process of voltage drop and recovery after disturbance, but also can further output capacitive reactive power increment to the power grid under the regulation of the excitation system when the voltage difference between the internal potential and the power grid is increased. When the generator operates in a steady state, the higher the capacitive reactive output level of the generator is, the larger the total amount of capacitive reactive power injected into the power grid by the disturbed generator set is, and the voltage stability of the power grid is favorably maintained.
Although different dynamic and static reactive power control methods can regulate and control the system steady-state voltage to a target expected value, due to the obvious difference of the characteristics of the dynamic reactive voltage between static passive elements such as a capacitor and a reactor and a local excitation automatic regulation generator, the dynamic voltage recovery characteristics in the transient process of the system can be greatly influenced, and how to coordinate the reasonable proportion of reactive power output of reactive power compensation equipment such as a generator set and a capacitor under different voltage levels is a problem to be solved urgently at present.
Therefore, a method for controlling dynamic and static reactive coordination of a multi-dc feed system at different voltage levels is needed.
Disclosure of Invention
The invention provides a method and a system for determining a dynamic and static reactive power coordination control strategy of a multi-direct-current feed-in system, and aims to solve the problem of how to determine the dynamic and static reactive power coordination control strategy of the multi-direct-current feed-in system.
In order to solve the above problem, according to an aspect of the present invention, there is provided a method for determining a dynamic and static reactive power coordination control strategy of a multiple direct current feed-in system, the method including:
step 1, in a built data model of a direct current feed-in alternating current power grid, adjusting a generator terminal voltage of a generator to be a first preset generator terminal voltage threshold value, and adjusting reactive power output of a capacitor and the number of the generators to enable the overall system operation voltage of the direct current feed-in alternating current power grid in a current operation mode to be a preset systematized overall operation voltage threshold value;
step 2, performing N-1 fault checking on the direct current feed-in alternating current power grid in the current operation mode to obtain a first checking result;
step 3, when the first check result indicates that the direct current fed into the alternating current power grid is in a system stable state, reducing the terminal voltage of a generator, increasing the reactive power output of a capacitor, and maintaining the integral operation voltage of the system of the direct current fed into the alternating current power grid unchanged;
step 4, performing N-1 fault check on the direct current fed into the alternating current power grid in the current operation mode to obtain a second check result;
step 5, when the second check result indicates that the direct current input alternating current power grid is in a system unstable state, determining a dynamic and static reactive power coordination control strategy under the current system overall operation voltage according to the operation mode of the direct current input alternating current power grid in the system stable state at the last time; wherein, the dynamic and static reactive power coordination control strategy comprises: the minimum starting number of the generator, the minimum generator terminal voltage of the generator and the reactive power output condition of the corresponding capacitor are generated under the integral operation voltage of the current system.
Preferably, wherein the method further comprises:
before the starting number of the generators is adjusted, carrying out direct-current monopole blocking fault simulation, and determining the transient supporting capacity sequence of the generators according to the reactive integral values of the generators from the fault clearing moment to the fault recovery stage and the magnitude of the reactive integral values; wherein, the lower the reactive integral value, the more the unit of the reserve of the tendency of falling first.
Preferably, wherein the reactive integral value of the generator is determined using the following formula:
Figure BDA0002283084860000031
wherein, t0Indicating the fault removal time; t is t1Representing the reactive integration cut-off time of the generator; q0iIndicating that the generator i is initially idle; qi(t) denotes the generator i at tThe idle output of carving; qiRepresenting the reactive power output integral value of the generator i within the integral time.
Preferably, wherein the method further comprises:
and when the first check result indicates that the direct current input alternating current power grid is in a system unstable state, increasing the near-zone spinning reserve capacity of the direct current receiving end according to a first preset adjustment strategy, increasing the starting number of the generators, reducing the reactive power output of the capacitor, maintaining the integral operation voltage of the system of the direct current input alternating current power grid unchanged, and returning to the step 2 to obtain the first check result again.
Preferably, wherein the method further comprises:
when the second check result indicates that the direct current input alternating current power grid is in a system stable state, if the reactive power output of the capacitor can be continuously increased in the current operation mode and the terminal voltage is greater than a second preset terminal voltage threshold value, reducing the terminal voltage of the generator, increasing the reactive power output of the capacitor, maintaining the overall operation voltage of the system of the direct current input alternating current power grid unchanged, and returning to the step 4 to obtain a second check result again;
and when the second check result indicates that the direct current input alternating current power grid is in a system stable state, if the reactive power output of the capacitor cannot be continuously increased in the current operation mode or the terminal voltage is less than or equal to a second preset terminal voltage threshold value, determining a dynamic and static reactive power coordination control strategy under the current overall operation voltage of the system according to the current operation mode when the direct current input alternating current power grid is in the system stable state.
Preferably, wherein the method further comprises:
and if the current system overall operation voltage is larger than the preset allowable operation voltage threshold, reducing the current system overall operation voltage according to the preset system overall operation voltage adjustment step threshold, taking the adjusted system overall operation voltage as the preset systematized overall operation voltage threshold, and returning to the step 1.
According to another aspect of the present invention, there is provided a system for determining a dynamic and static reactive power coordination control strategy of a multiple direct current feed-in system, the system comprising:
the initial operation mode adjusting unit is used for adjusting the terminal voltage of the generator to be a first preset terminal voltage threshold value in a built data model of the direct current feed-in alternating current power grid, and adjusting the reactive power output of the capacitor and the starting number of the generator so that the overall system operation voltage of the direct current feed-in alternating current power grid in the current operation mode is a preset systemic overall operation voltage threshold value;
the first check result acquisition unit is used for carrying out N-1 fault check on the direct current feed-in alternating current power grid in the current operation mode to acquire a first check result;
the first operation mode adjusting unit is used for reducing the terminal voltage of the generator, increasing the reactive power output of the capacitor and maintaining the integral operation voltage of the system of the direct current input alternating current power grid unchanged when the first check result indicates that the direct current input alternating current power grid is in the system stable state;
the second check result acquisition unit is used for performing N-1 fault check on the direct current fed into the alternating current power grid in the current operation mode so as to acquire a second check result;
a dynamic and static reactive power coordination control strategy determining unit, configured to determine a current dynamic and static reactive power coordination control strategy under the overall system operation voltage according to an operation mode of the dc fed-in ac power grid in the system stable state last time when the second check result indicates that the dc fed-in ac power grid is in the system unstable state; wherein, the dynamic and static reactive power coordinated control strategy comprises: the minimum starting number of the generator, the minimum generator terminal voltage of the generator and the reactive power output condition of the corresponding capacitor are generated under the integral operation voltage of the current system.
Preferably, wherein the system further comprises:
the transient supporting capacity sequence determining unit is used for performing direct-current monopole blocking fault simulation before the starting number of the generators is adjusted, determining a transient supporting capacity sequence of the generators according to a reactive integral value of the generators from the fault clearing time to the fault recovery stage and according to the size of the reactive integral value; wherein, the lower the reactive integral value, the more the unit of the reserve of the tendency of falling first.
Preferably, the transient supporting capability order determination unit determines the reactive power integral value of the generator using the following formula:
Figure BDA0002283084860000051
wherein, t0Indicating the fault removal time; t is t1Representing the reactive integration cut-off time of the generator; q0iIndicating that the generator i is initially idle; qi(t) represents the reactive power output of the generator i at time t; qiRepresenting the reactive power output integral value of the generator i within the integral time.
Preferably, wherein the system further comprises:
and the second operation mode adjusting unit is used for increasing the near-area spinning reserve capacity of the direct current receiving end according to a first preset adjusting strategy, increasing the starting number of the generator, reducing the reactive power output of the capacitor, keeping the integral operation voltage of the system of the direct current fed into the alternating current power grid unchanged, and returning to the first checking result obtaining unit to obtain the first checking result again when the first checking result indicates that the direct current fed into the alternating current power grid is in a system unstable state.
Preferably, the first operation mode adjusting unit is further configured to:
when the second check result indicates that the direct-current fed-in alternating-current power grid is in a system stable state, if the reactive power output of the capacitor can be continuously increased in the current operation mode and the terminal voltage is greater than a second preset terminal voltage threshold, the terminal voltage of the generator is reduced, the reactive power output of the capacitor is increased, the overall operation voltage of the system of the direct-current fed-in alternating-current power grid is maintained unchanged, and the second check result is returned to the second check result acquisition unit to obtain a second check result again;
and when the second check result indicates that the direct current input alternating current power grid is in a system stable state, if the reactive power output of the capacitor cannot be continuously increased in the current operation mode or the terminal voltage is less than or equal to a second preset terminal voltage threshold value, determining a dynamic and static reactive power coordination control strategy under the current overall operation voltage of the system according to the current operation mode when the direct current input alternating current power grid is in the system stable state.
Preferably, wherein the system further comprises:
and the preset systematic whole operation voltage threshold value adjusting unit is used for reducing the current system whole operation voltage according to the preset system whole operation voltage adjusting step threshold value if the current system whole operation voltage is larger than the preset allowable operation voltage threshold value, taking the adjusted system whole operation voltage as the preset systematic whole operation voltage threshold value, and returning to the initial operation mode adjusting unit.
The invention provides a method and a system for determining a dynamic and static reactive power coordination control strategy of a multi-direct-current feed-in system, which can determine the dynamic and static reactive power coordination control strategy for a receiving-end power grid, particularly a multi-direct-current feed-in receiving end, can provide reference for aspects such as power grid planning, operation and the like of the receiving-end power grid, and provide basis for optimization of a starting mode and design of power grid safety and stability control.
Drawings
A more complete understanding of exemplary embodiments of the present invention may be had by reference to the following drawings in which:
fig. 1 is a flowchart of a method 100 for determining a dynamic and static reactive power coordination control strategy of a multiple dc feed-in system according to an embodiment of the present invention;
fig. 2 is a flowchart of a method for determining a dynamic and static reactive power coordination control strategy of a multiple dc feed-in system according to an embodiment of the present invention;
figure 3 is a diagram of a qishao dc drop point near-region grid structure according to an embodiment of the present invention;
figure 4 is a plot of dc near dc reserve-free dc power in the keemun dc region according to an embodiment of the present invention;
figure 5 is a network tidal current diagram for the qishao dc near field 530kV voltage level, 1019MW spinning reserve capacity, 1.03pu terminal voltage mode of operation, according to an embodiment of the present invention;
fig. 6 is a reactive power output curve diagram in a Hunan pond machine set terminal voltage 1.03pu operation mode according to the embodiment of the present invention;
figure 7 is a network tidal current diagram for the qishao dc near field 530kV voltage level, 1019MW spinning reserve capacity, 1.02pu terminal voltage mode of operation, according to an embodiment of the present invention;
FIG. 8 is a reactive power output curve diagram of a Hunan pond unit at different terminal voltage levels according to an embodiment of the invention; and
fig. 9 is a schematic structural diagram of a system 900 for determining a dynamic and static reactive power coordination control strategy of a multiple direct current feed-in system according to an embodiment of the present invention.
Detailed Description
Example embodiments of the present invention will now be described with reference to the accompanying drawings, however, the invention may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein, which are provided for a complete and complete disclosure of the invention and to fully convey the scope of the invention to those skilled in the art. The terminology used in the exemplary embodiments illustrated in the accompanying drawings is not intended to be limiting of the invention. In the drawings, the same units/elements are denoted by the same reference numerals.
Unless otherwise defined, terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Further, it will be understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense.
Fig. 1 is a flowchart of a method 100 for determining a dynamic and static reactive power coordination control strategy of a multiple direct current feed-in system according to an embodiment of the present invention. As shown in fig. 1, the embodiment of the present invention provides a method for determining a dynamic and static reactive power coordination control strategy of a multiple direct current feed-in system, which can determine a dynamic and static reactive power coordination control strategy for a receiving-end power grid, particularly for a multiple direct current feed-in receiving end, can provide reference for power grid planning, operation, and other aspects of the receiving-end power grid, and provide a basis for optimization of a startup mode and design of power grid safety and stability control. The method 100 for determining the dynamic and static reactive power coordination control strategy of the multi-direct-current feed-in system provided by the embodiment of the invention starts from step 101, and in step 101, in a built data model of the direct-current feed-in alternating-current power grid, the terminal voltage of a generator is adjusted to be a first preset terminal voltage threshold, and the reactive power output of a capacitor and the starting number of the generator are adjusted, so that the overall system operation voltage of the direct current fed into the alternating-current power grid in the current operation mode is a preset systematic overall operation voltage threshold.
Preferably, wherein the method further comprises:
before the starting number of the generators is adjusted, carrying out direct-current monopole blocking fault simulation, and determining the transient supporting capacity sequence of the generators according to the reactive integral values of the generators from the fault clearing moment to the fault recovery stage and the magnitude of the reactive integral values; wherein, the lower the reactive integral value, the more the unit of the reserve of the tendency of falling first.
Preferably, wherein the reactive integral value of the generator is determined using the following formula:
Figure BDA0002283084860000071
wherein, t0Indicating the fault removal time; t is t1Representing the reactive integration cut-off time of the generator; q0iIndicating that the generator i is initially idle; qi(t) represents the reactive power output of the generator i at time t; qiRepresenting the reactive power output integral value of the generator i within the integral time.
In the embodiment of the invention, firstly, power system simulation software is adopted, and a model of tide data and stable data of the multi-direct-current feed-in alternating-current power grid is built according to the structure of the multi-direct-current feed-in receiving end alternating-current power grid. And then, adjusting a starting mode to enable zero standby in the current direct current drop point near region and guarantee that the transmission power of a connecting line is within an allowable value range, and adjusting the terminal voltage of the generator, the starting number and the reactive power output of the capacitor to enable the overall system operation voltage of the direct current fed into the alternating current power grid in the current operation mode to be a preset systemic overall operation voltage threshold value. The generator terminal voltage of the generator is adjusted to 1.03pu, and the overall operation voltage level of the system is adjusted to a preset systematized overall operation voltage threshold value.
Before the starting mode is adjusted, carrying out direct-current monopole blocking fault simulation, sequencing the transient supporting capability of the generator according to a reactive integral value from the fault clearing moment to the fault recovery stage, wherein the lower the integral value is, the more the rotary unit tends to be reduced, and the integral value is calculated as the following formula:
Figure BDA0002283084860000081
wherein, t0Indicating the fault removal time; t is t1Representing the reactive integration cut-off time of the generator; q0iIndicating that the generator i is initially idle; qi(t)Representing the reactive power output of the generator i at the moment t; qiRepresenting the reactive power output integral value of the generator i within the integral time.
In step 102, the dc feed-in ac grid in the current operation mode is subjected to N-1 fault checking to obtain a first checking result.
In step 103, when the first check result indicates that the dc input ac power grid is in a system stable state, the generator terminal voltage of the generator is reduced, the reactive power output of the capacitor is increased, and the overall system operating voltage of the dc input ac power grid is maintained unchanged.
Preferably, wherein the method further comprises:
when the first check result indicates that the direct current input alternating current power grid is in a system unstable state, increasing the near-zone spinning reserve capacity of the direct current receiving end according to a first preset adjustment strategy, increasing the starting number of the generators, reducing the reactive power output of the capacitor, maintaining the integral operation voltage of the system of the direct current input alternating current power grid unchanged, and returning to the step 102 to obtain the first check result again.
In an embodiment of the present invention, if the first check result indicates that the dc input ac grid is in a system stable state, the generator terminal voltage of the generator is reducedAnd increasing the reactive output of the capacitor, maintaining the overall operation voltage of the system with the direct current fed into the alternating current power grid unchanged, and performing check again in step 104 to obtain a second check result. Wherein, when the generator terminal voltage is reduced, the step length is adjusted to be 0.1pu each time, namely delta Eq＝0.1pu。
If the first check result indicates that the direct current feed-in alternating current power grid is in a system unstable state, adjusting a starting mode of a near-zone generator at a direct current receiving and inputting point, increasing the rotating reserve capacity, increasing the step length by 20MW each time, reducing the reactive power output of a capacitor, and keeping the overall operation voltage of the system of the direct current feed-in alternating current power grid unchanged, wherein the calculation formula is as follows: p is N Δ P, where P represents the total reserve capacity for rotation in the near zone of the dc drop point; n represents the number of times of the startup mode adjustment, and N is 0, 1, 2, 3 … …; and Δ P represents a system voltage adjustment step size, and Δ P is 20 MW.
In step 104, the dc feed into the ac grid in the current operation mode is subjected to N-1 fault checking to obtain a second checking result.
In step 105, when the second check result indicates that the dc fed-back ac grid is in a system unstable state, determining a dynamic and static reactive power coordination control strategy under the current overall system operation voltage according to an operation mode of the dc fed-back ac grid in the system stable state last time; wherein, the dynamic and static reactive power coordination control strategy comprises: the minimum starting number of the generator, the minimum generator terminal voltage of the generator and the reactive power output condition of the corresponding capacitor are generated under the integral operation voltage of the current system.
Preferably, wherein the method further comprises:
when the second check result indicates that the dc-fed ac power grid is in the system stable state, if the reactive power output of the capacitor can be continuously increased in the current operation mode and the terminal voltage is greater than the second preset terminal voltage threshold, decreasing the terminal voltage of the generator, increasing the reactive power output of the capacitor, and maintaining the overall operation voltage of the system of the dc-fed ac power grid unchanged, and returning to step 104 to obtain the second check result again;
and when the second check result indicates that the direct current input alternating current power grid is in a system stable state, if the reactive power output of the capacitor cannot be continuously increased in the current operation mode or the terminal voltage is less than or equal to a second preset terminal voltage threshold value, determining a dynamic and static reactive power coordination control strategy under the current overall operation voltage of the system according to the current operation mode when the direct current input alternating current power grid is in the system stable state.
In the embodiment of the invention, if the second check result indicates that the direct current feed-in alternating current power grid is in a system unstable state, outputting the operation mode when the previous group of systems is stable, wherein the output mode is a dynamic and static reactive power coordination control strategy at the voltage level; wherein, the dynamic and static reactive power coordination control strategy comprises: the minimum starting number of the generator, the minimum generator terminal voltage of the generator and the reactive power output condition of the corresponding capacitor are generated under the integral operation voltage of the current system.
When the second check result indicates that the dc-fed ac power grid is in the system stable state, if the reactive power output of the capacitor can be continuously increased in the current operation mode and the terminal voltage is greater than the second preset terminal voltage threshold value 0.97pu, the terminal voltage of the generator is reduced, the reactive power output of the capacitor is increased, the overall operation voltage of the system of the dc-fed ac power grid is maintained unchanged, and the step 104 is returned to obtain the second check result again.
And when the second check result indicates that the direct current input alternating current power grid is in a system stable state, if the reactive power output of the capacitor cannot be continuously increased in the current operation mode or the terminal voltage is less than or equal to a second preset terminal voltage threshold value 0.97pu, determining a dynamic and static reactive power coordination control strategy under the current overall operation voltage of the system according to the current operation mode when the direct current input alternating current power grid is in the system stable state.
Preferably, wherein the method further comprises:
if the current system overall operation voltage is greater than the preset allowable operation voltage threshold, reducing the current system overall operation voltage according to the preset system overall operation voltage adjustment step threshold, taking the adjusted system overall operation voltage as the preset systematized overall operation voltage threshold, and returning to the step 101.
In the embodiment of the invention, when determining the dynamic and static coordination reactive power control strategy under different voltages, the formula U is used as U0-k Δ U, adjusted to determine different preset systematized overall operating voltage thresholds. Wherein U represents a preset overall system operation voltage threshold; u shape0The initial operation voltage of the system is represented and is the highest allowable value of the overall operation voltage of the system; k represents the number of circulation of the circulation body, k is 0, 1, 2, 3 … …; Δ U represents a voltage adjustment step size, and in the first operation, U ═ U0The value of U gradually decreases.
For example, if the maximum allowable value of the overall operation voltage of the system is 530kV, the voltage adjustment step is 5kV, and the preset allowable operation voltage threshold is 515kV, first determining that the preset overall operation voltage threshold of the system is 530kV, adjusting the startup mode to make the overall operation voltage of the system be 530kV, and determining a dynamic and static reactive power coordination control strategy corresponding to the 530kV voltage; then, re-determining that the preset integral operation voltage threshold is 525kV, returning to the step 101 to adjust the starting mode, so that the integral operation voltage of the system is 525kV, and determining a dynamic and static reactive power coordination control strategy corresponding to the 525kV voltage; and stopping calculation until the integral system operation voltage corresponding to the current operation mode is equal to a preset allowable operation voltage threshold value 515kV, namely stopping calculation after determining a dynamic and static reactive power coordination control strategy corresponding to the 515kV voltage.
Fig. 2 is a flowchart of a method for determining a dynamic and static reactive power coordination control strategy of a multiple direct current feed-in system according to an embodiment of the present invention. As shown in fig. 2, the method for determining the dynamic and static reactive power coordination control strategy of the multiple direct current feed-in system includes the steps of:
and S1, building a data model of the multi-direct-current feed-in alternating-current power grid.
And S2, adjusting the generator terminal voltage of the generator to a first preset generator terminal voltage threshold value of 1.03pu, and adjusting the starting number of the generator and the reactive power output of the capacitor to enable the overall operation voltage of the system to be a preset overall system voltage threshold value.
S3, performing N-1 fault check on the direct current fed into the alternating current power grid in the current operation mode to obtain a first check result.
S4, judging whether the first checking result indicates that the system is stable; if stable, go to S5; if not, the process proceeds to S9.
And S5, reducing the terminal voltage of the generator, increasing the reactive power output of the capacitor, and maintaining the integral operation voltage of the system with the direct current fed into the alternating current power grid unchanged.
And S6, performing N-1 fault check on the direct current fed into the alternating current power grid in the current operation mode to obtain a second check result.
S7, judging whether the second check result indicates that the system is stable; if not, go to S8; if stable, the process proceeds to S10.
S8, a second check result indicates that the system is unstable, and a dynamic and static reactive power coordination control strategy under the current overall system operation voltage is determined according to the operation mode when the direct current is fed into the alternating current power grid at the last time and is in the system stable state; wherein, the dynamic and static reactive power coordination control strategy comprises: the minimum starting number of the generators, the minimum generator terminal voltage of the generators and the reactive power output condition of the corresponding capacitors are generated under the current overall system operation voltage, and the process goes to S13.
And S9, increasing the near-zone spinning reserve capacity of the direct current receiving end, increasing the starting number of the generator, reducing the reactive power output of the capacitor, maintaining the integral operation voltage of the system with the direct current fed into the alternating current power grid unchanged, and returning to S3.
S10, judging whether the reactive power output of the capacitor can be continuously increased and the current terminal voltage Eq is greater than a second preset terminal voltage threshold value 0.97 pu; if yes, go to S5; if not, the process proceeds to S11.
And S11, determining a dynamic and static reactive power coordination control strategy under the current overall system operation voltage according to the current operation mode when the direct current is fed into the alternating current power grid and is in the system stable state, and entering S12.
S12, judging whether the current system integral operation voltage is less than or equal to a preset allowable operation voltage threshold value; if not, go to S13; if yes, ending;
and S13, reducing the current overall system operating voltage according to the preset overall system operating voltage adjusting step threshold, taking the adjusted overall system operating voltage as the preset systemic overall operating voltage threshold, and entering S2.
The following takes the near region of the qishao dc falling point as an example to further explain the specific implementation mode of the invention.
And (1) building a data model of a multi-direct-current feed-in alternating-current power grid.
The direct current engineering already put into production in China includes Hami-Zheng, Sanxia-east China and Sanxia-south China, and the direct current engineering put into production is expected to be spring-Hunan. Taking the falling point near area of Qishao DC as an example, the DC transmission power of the Qishao DC is 4500 MW. In the PSD-BPA program, the system reference capacity is 1000MVA, and the device parameters are all per unit values taking the system reference capacity as a reference. The specific power grid structure of the Keysao direct current falling point near region is shown in figure 3.
And (2) adjusting the starting-up mode, the whole voltage level of the system and the terminal voltage.
And adjusting a starting mode to enable zero standby in a Kelly Shao direct current falling point near region and ensure that the transmission power of a connecting line is in an allowable value range, adjusting the voltage of a generator terminal to 1.03pu, and horizontally adjusting the whole operation voltage of the system to be close to the maximum allowable value 530kV, namely U0 is 530 kV. The transient support effects of the generators are sorted, XiangShimen, Xiangwuqiang, Xiangbaoqing, Xiangyou county, Xiangquan lake and XiangChangsha and adjacent region machine sets are used as priority starting machine sets, rotating standby capacity is preferentially increased, the transient support effects of the Hunan three-plate, Xiangtuo, Xiangzhui river, Xianghuayue, Xiangripple source, Xiangyi Yiyang, Xiangzhui and Xiangui are smaller in integrated value, and the power-off state is kept to the maximum extent.
Step (3), performing N-1 simulation calculation on the adjusted operation mode, and entering step (4) if the simulation result indicates that the system is unstable; and if the simulation result indicates that the system is stable, the step (12) is carried out.
Adjusting the starting mode to enable zero standby in a Keosha direct current falling point near region and ensure that the transmission power of a connecting line is within an allowable value range, adjusting the generator terminal voltage to 1.03pu, performing N-1 simulation calculation on the adjusted operation mode, and showing that the system is unstable and a Keosha direct current near region non-standby direct current power curve is shown in figure 4.
And (4) destabilizing the system, adjusting the starting mode of the direct current receiving station near-area generator, increasing the rotating reserve capacity, reducing the reactive power output of the capacitor and maintaining the voltage level unchanged.
Adjusting the starting mode of a power generator at a near area of a Keoshao direct current receiving station, taking Hunan Shimen, Xiangwuqiang, Xiangbaoqing, Xiangyou county, Xianghun lake, Xiangchangsha, Xiangchangde and Xiangzhuanxi machine sets as priority starting machine sets, keeping the voltage of the machine end at 1.03pu, increasing the rotating spare capacity to 1019MW, and respectively keeping the number and the capacity of capacitor sets input by a Ridge node, a civil Feng node, a Hengyang node, an ancient pavilion node, a Suzuo node, a Xingcheng node, a Yutian node, a sand terrace node and a renaming node at 60Mvar, 2Mvar, 60Mvar, 3Mvar, 60Mvar, 5Mvar, 40Mvar, 60Mvar, 4Mvar, 60Mvar, 3Mvar and 530 Mvar at the whole level.
And (5) carrying out N-1 simulation calculation on the adjusted operation mode.
According to simulation results, the system is stable in the operation mode of 530kV voltage level, 1019MW standby capacity and near zone generator terminal voltage of 1.03pu, a network tidal current graph is shown in fig. 5, and a reactive power curve of a Hunan pool generator in the operation mode is shown in fig. 6.
And (6) stabilizing the system, reducing the voltage at the generator terminal of the generator, increasing the reactive power output of the capacitor and maintaining the same voltage level.
According to the calculation result, the system is stable, the voltage at the generator terminal is reduced, the step length is 0.1pu each time, namely, the delta Eq is 0.1pu, the number of the capacitor input groups is increased, and the voltage level is maintained. Delta u is 0.1pu, N is 1, the terminal voltage of the Hunan Shimen, Xiangwuqiang, Xiangbaqing, Xiangyou county, Xianghuntan, XiangChangsha, Xianghede and Xiangcuxixi machine set is reduced to 1.02pu, a set of 60Mvar capacitors is put into the Ridge node, a set of 30Mvar capacitors is put into the Yutian node, a set of 40Mvar capacitors is put into the Xincheng node, and the voltage level is maintained at 530 kV. The QiShao DC near 530 voltage level, 1019MW rotation DC power curve is shown in figure 7.
And (7) carrying out N-1 simulation calculation on the operation mode after the terminal voltage is reduced, and adjusting the starting mode.
And (4) calculating according to the operation mode adjusted in the step (6), finding out the instability of the system, returning to the step (4) to continuously adjust the starting mode, adjusting the step size to be 20MW each time, reducing the output of 650MW to the output of 610MW for the Xiang Baoqing 02 unit, and increasing the output of 40MW for the Xiang Jiang puer unit. Reactive output curves of the Hunan Tan machine set at different terminal voltage levels are shown in FIG. 8.
And (8) reducing the voltage at the generator terminal, increasing the reactive power output of the capacitor and maintaining the same voltage level.
The generator terminal voltage is reduced, the step length is 0.1pu each time, namely delta Eq is 0.1pu, the number of input groups of the capacitors is increased, and the voltage level is maintained. The generator terminal voltage of Xiangshimen, Xiangwuqiang, Xiangbaoqing, Xiangyou county, Xianghuntan, XiangChangsha, Xiangchangde and Xiangzhuanxixi machine units is reduced to 1.01pu, 60Mvar capacitors are respectively added into ancient pavilion nodes and Suyan nodes, and the voltage level is maintained at 530 kV.
And (9) carrying out N-1 simulation calculation on the adjusted operation mode.
The calculation result shows that the system is stable, and at the moment, the direct current near-zone capacitor bank is completely put into use, and the voltage at the generator terminal can not maintain the 530kV voltage level when the direct current near-zone capacitor bank is continuously reduced. Go to the next step.
And (10) judging whether the overall operation voltage level of the system is less than the lowest allowable operation voltage or not.
At the moment, the output operation mode is that under the 530kV voltage level of the Kelly Shao direct current near region, the voltage levels of different generator terminals of the generator and the steady-state reactive power output matching condition of the capacitor bank, and the current Kelly Shao direct current falling point near region voltage is higher than the lowest allowable operation voltage of 515 kV. And (4) according to the operation mode of the generator terminal voltage 1.03pu under the voltage level of 530 in the step (4), continuously reducing the reactive power output of the capacitor bank, reducing the overall operation voltage of the system to 525kV, and returning to the step (2).
(11) If the step (10) judges that the overall operation voltage level of the system is less than the lowest allowable operation voltage.
After the voltage level of the whole system in the near-region of the Qishao direct current falling point is gradually reduced to 515kV, the operation control strategies under different voltage levels are output, and the cycle is ended.
Fig. 9 is a schematic structural diagram of a system 900 for determining a dynamic and static reactive power coordination control strategy of a multiple direct current feed-in system according to an embodiment of the present invention. As shown in fig. 9, a system 900 for determining a dynamic and static reactive power coordination control strategy of a multiple direct current feed-in system according to an embodiment of the present invention includes: an initial operation mode adjusting unit 901, a first checking result obtaining unit 902, a first operation mode adjusting unit 903, a second checking result obtaining unit 904, and a dynamic and static reactive power coordination control strategy determining unit 905.
Preferably, the initial operation mode adjusting unit 901 is configured to, in the built data model of the dc-fed ac power grid, adjust a generator terminal voltage of the generator to be a first preset generator terminal voltage threshold, and adjust a reactive power output of the capacitor and a number of generators that are started, so that an overall operation voltage of the system of the dc-fed ac power grid in the current operation mode is a preset systemic overall operation voltage threshold.
Preferably, the first check result obtaining unit 902 is configured to perform N-1 fault check on the dc-fed ac power grid in the current operation mode to obtain a first check result.
Preferably, the first operation mode adjustment unit 903 is configured to, when the first check result indicates that the dc fed into the ac power grid is in a system stable state, reduce a generator terminal voltage of the generator, increase a reactive power output of the capacitor, and maintain a system overall operation voltage of the dc fed into the ac power grid unchanged.
Preferably, wherein the system further comprises: and the second operation mode adjusting unit is used for increasing the near-area spinning reserve capacity of the direct current receiving end according to a first preset adjusting strategy, increasing the starting number of the generator, reducing the reactive power output of the capacitor, keeping the integral operation voltage of the system of the direct current fed into the alternating current power grid unchanged, and returning to the first checking result obtaining unit to obtain the first checking result again when the first checking result indicates that the direct current fed into the alternating current power grid is in a system unstable state.
Preferably, the second check result obtaining unit 904 is configured to perform N-1 fault check on the dc fed into the ac power grid in the current operation mode, so as to obtain a second check result.
Preferably, the dynamic and static reactive power coordination control strategy determining unit 905 is configured to determine, when the second check result indicates that the dc-fed ac power grid is in a system unstable state, a dynamic and static reactive power coordination control strategy under the current system overall operation voltage according to an operation mode of the dc-fed ac power grid in the system stable state last time; wherein, the dynamic and static reactive power coordination control strategy comprises: the minimum starting number of the generator, the minimum generator terminal voltage of the generator and the reactive power output condition of the corresponding capacitor are generated under the integral operation voltage of the current system.
Preferably, wherein the system further comprises:
the transient supporting capacity sequence determining unit is used for carrying out direct-current monopole blocking fault simulation before the startup number of the generators is adjusted, determining the transient supporting capacity sequence of the generators according to the reactive integral value of the generators from the fault clearing moment to the fault recovery stage and the magnitude of the reactive integral value; wherein, the lower the reactive integral value, the more the unit of the reserve of the tendency of falling first.
Preferably, the transient supporting capability order determination unit determines the reactive power integral value of the generator using the following formula:
Figure BDA0002283084860000161
wherein, t0Indicating the fault removal time; t is t1Representing the reactive integration cut-off time of the generator; q0iIndicating that the generator i is initially idle; qi(t) represents the reactive power output of the generator i at time t; qiRepresenting the reactive power output integral value of the generator i within the integral time.
Preferably, the first operation mode adjusting unit is further configured to:
when the second check result indicates that the direct-current fed-in alternating-current power grid is in a system stable state, if the reactive power output of the capacitor can be continuously increased in the current operation mode and the terminal voltage is greater than a second preset terminal voltage threshold, the terminal voltage of the generator is reduced, the reactive power output of the capacitor is increased, the overall operation voltage of the system of the direct-current fed-in alternating-current power grid is maintained unchanged, and the second check result is returned to the second check result acquisition unit to obtain a second check result again;
and when the second check result indicates that the direct current input alternating current power grid is in a system stable state, if the reactive power output of the capacitor cannot be continuously increased in the current operation mode or the terminal voltage is less than or equal to a second preset terminal voltage threshold value, determining a dynamic and static reactive power coordination control strategy under the current overall operation voltage of the system according to the current operation mode when the direct current input alternating current power grid is in the system stable state.
Preferably, wherein the system further comprises: and the preset systematic whole operation voltage threshold value adjusting unit is used for reducing the current system whole operation voltage according to the preset system whole operation voltage adjusting step threshold value if the current system whole operation voltage is larger than the preset allowable operation voltage threshold value, taking the adjusted system whole operation voltage as the preset systematic whole operation voltage threshold value, and returning to the initial operation mode adjusting unit.
The system 900 for determining the dynamic and static reactive power coordination control strategy of the multiple dc feed-in system according to the embodiment of the present invention corresponds to the method 100 for determining the dynamic and static reactive power coordination control strategy of the multiple dc feed-in system according to another embodiment of the present invention, and therefore, no further description is provided herein.
The invention has been described with reference to a few embodiments. However, other embodiments of the invention than the one disclosed above are equally possible within the scope of the invention, as would be apparent to a person skilled in the art from the appended patent claims.
Generally, all terms used in the claims are to be interpreted according to their ordinary meaning in the technical field, unless explicitly defined otherwise herein. All references to "a/an/the [ means, component, etc ]" are to be interpreted openly as referring to at least one instance of said means, component, etc., unless explicitly stated otherwise. The steps of any method disclosed herein do not have to be performed in the exact order disclosed, unless explicitly stated.
As will be appreciated by one skilled in the art, embodiments of the present application may be provided as a method, system, or computer program product. Accordingly, the present application may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, the present application may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, and the like) having computer-usable program code embodied therein.
The present application is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the application. It will be understood that each flow and/or block of the flow diagrams and/or block diagrams, and combinations of flows and/or blocks in the flow diagrams and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a general purpose computer, special purpose computer, embedded force output device, or other programmable data output apparatus to produce a machine, such that the instructions, which execute via the force output device of the computer or other programmable data output apparatus, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.
These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data output apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.
These computer program instructions may also be loaded onto a computer or other programmable data output device to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented output such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.
Finally, it should be noted that: the above embodiments are only for illustrating the technical solutions of the present invention and not for limiting the same, and although the present invention is described in detail with reference to the above embodiments, those of ordinary skill in the art should understand that: modifications and equivalents may be made to the embodiments of the invention without departing from the spirit and scope of the invention, which is to be covered by the claims.

Claims (12)

1. A method for determining a dynamic and static reactive power coordination control strategy of a multi-direct current feed-in system is characterized by comprising the following steps:
step 1, in a built data model of a direct current feed-in alternating current power grid, adjusting a generator terminal voltage of a generator to be a first preset generator terminal voltage threshold value, and adjusting reactive power output of a capacitor and the number of the generators to enable the overall system operation voltage of the direct current feed-in alternating current power grid in a current operation mode to be a preset systemic overall operation voltage threshold value;
step 2, performing N-1 fault checking on the direct current feed-in alternating current power grid in the current operation mode to obtain a first checking result;
step 3, when the first check result indicates that the direct current feed-in alternating current power grid is in a system stable state, reducing the generator terminal voltage of the generator, increasing the reactive power output of the capacitor, and maintaining the integral operation voltage of the system of the direct current feed-in alternating current power grid unchanged;
step 4, performing N-1 fault check on the direct current feed-in alternating current power grid in the current operation mode to obtain a second check result;
step 5, when the second check result indicates that the direct current feed-in alternating current power grid is in a system unstable state, determining a dynamic and static reactive power coordination control strategy under the current system overall operation voltage according to the operation mode of the direct current feed-in alternating current power grid in the system stable state last time; wherein, the dynamic and static reactive power coordination control strategy comprises: the minimum starting number of the generator, the minimum generator terminal voltage of the generator and the reactive power output condition of the corresponding capacitor are generated under the integral operation voltage of the current system.
2. The method of claim 1, further comprising:
before the starting number of the generators is adjusted, carrying out direct-current monopole blocking fault simulation, and determining the transient supporting capacity sequence of the generators according to the reactive integral values of the generators from the fault clearing moment to the fault recovery stage and the magnitude of the reactive integral values; wherein, the lower the reactive integral value, the more the unit of the reserve of the tendency of falling first.
3. A method according to claim 2, characterized in that the reactive integral value of the generator is determined by means of the following formula:
Figure 398144DEST_PATH_IMAGE002
，
wherein, t0Indicating the fault removal time; t is t1Representing the reactive integration cut-off time of the generator; q0iIndicating that the generator i is initially idle; qi(t) represents the reactive power output of the generator i at time t; qiRepresenting the reactive power output integral value of the generator i within the integral time.
4. The method of claim 1, further comprising:
and when the first check result indicates that the direct-current feed-in alternating-current power grid is in a system unstable state, increasing the rotational standby capacity of the direct-current receiving end near area according to a first preset adjustment strategy, increasing the starting number of the generators, reducing the reactive power output of the capacitor, maintaining the integral operation voltage of the system of the direct-current feed-in alternating-current power grid unchanged, and returning to the step 2 to obtain the first check result again.
5. The method of claim 1, further comprising:
when the second check result indicates that the direct-current feed-in alternating-current power grid is in a system stable state, if the reactive power output of the capacitor can be continuously increased in the current operation mode and the terminal voltage is greater than a second preset terminal voltage threshold value, reducing the terminal voltage of the generator, increasing the reactive power output of the capacitor, maintaining the overall operation voltage of the system of the direct-current feed-in alternating-current power grid unchanged, and returning to the step 4 to obtain a second check result again;
and when the second check result indicates that the direct-current feed-in alternating-current power grid is in a system stable state, if the reactive power output of the capacitor cannot be continuously increased in the current operation mode or the generator terminal voltage is less than or equal to a second preset generator terminal voltage threshold value, determining a dynamic and static reactive power coordination control strategy under the current overall operation voltage of the system according to the current operation mode when the direct-current feed-in alternating-current power grid is in the system stable state.
6. The method of claim 1, further comprising:
and if the current system overall operation voltage is larger than the preset allowable operation voltage threshold, reducing the current system overall operation voltage according to the preset system overall operation voltage adjustment step threshold, taking the adjusted system overall operation voltage as the preset systematized overall operation voltage threshold, and returning to the step 1.
7. A system for determining a dynamic and static reactive power coordination control strategy of a multi-feed dc system, the system comprising:
the initial operation mode adjusting unit is used for adjusting the terminal voltage of the generator to be a first preset terminal voltage threshold value in a built data model of the direct current feed-in alternating current power grid, and adjusting the reactive power output of the capacitor and the starting number of the generator so that the overall system operation voltage of the direct current feed-in alternating current power grid in the current operation mode is a preset systemic overall operation voltage threshold value;
the first checking result obtaining unit is used for carrying out N-1 fault checking on the direct current feed-in alternating current power grid in the current operation mode so as to obtain a first checking result;
the first operation mode adjusting unit is used for reducing the generator terminal voltage of the generator, increasing the reactive power output of the capacitor and maintaining the integral operation voltage of the system of the direct current feed-in alternating current power grid unchanged when the first check result indicates that the direct current feed-in alternating current power grid is in the system stable state;
the second check result acquisition unit is used for performing N-1 fault check on the direct current fed-in alternating current power grid in the current operation mode to acquire a second check result;
a dynamic and static reactive power coordination control strategy determining unit, configured to determine a current dynamic and static reactive power coordination control strategy under the overall system operation voltage according to an operation mode of the last time when the dc feed-in ac grid is in the system stable state when the second check result indicates that the dc feed-in ac grid is in the system unstable state; wherein, the dynamic and static reactive power coordination control strategy comprises: the minimum starting number of the generator, the minimum generator terminal voltage of the generator and the reactive power output condition of the corresponding capacitor are generated under the integral operation voltage of the current system.
8. The system of claim 7, further comprising:
the transient supporting capacity sequence determining unit is used for carrying out direct-current monopole blocking fault simulation before the startup number of the generators is adjusted, determining the transient supporting capacity sequence of the generators according to the reactive integral value of the generators from the fault clearing moment to the fault recovery stage and the magnitude of the reactive integral value; wherein, the lower the reactive integral value, the more the unit of the reserve of the tendency of falling first.
9. The system of claim 8, wherein the transient support capability sequence determination unit determines the reactive integral value of the generator using the following equation:
Figure 518547DEST_PATH_IMAGE002
，
wherein, t0Indicating the fault removal time; t is t1Representing the reactive integration cut-off time of the generator; q0iIndicating that the generator i is initially idle; qi(t) represents the reactive power output of the generator i at time t; qiRepresenting the reactive power output integral value of the generator i within the integral time.
10. The system of claim 7, further comprising:
and the second operation mode adjusting unit is used for increasing the near-area spinning reserve capacity of the direct current receiving end according to a first preset adjusting strategy, increasing the starting number of the generators, reducing the reactive power output of the capacitor, keeping the overall operation voltage of the system of the direct current feed-in alternating current power grid unchanged, and returning to the first check result obtaining unit to obtain the first check result again when the first check result indicates that the direct current feed-in alternating current power grid is in the system unstable state.
11. The system of claim 7, wherein the first operation mode adjustment unit is further configured to:
when the second check result indicates that the direct-current feed-in alternating-current power grid is in a system stable state, if the reactive power output of the capacitor can be continuously increased in the current operation mode and the generator terminal voltage is greater than a second preset generator terminal voltage threshold value, the generator terminal voltage of the generator is reduced, the reactive power output of the capacitor is increased, the overall operation voltage of the system of the direct-current feed-in alternating-current power grid is kept unchanged, and the second check result is returned to the second check result acquisition unit to obtain a second check result again;
and when the second check result indicates that the direct-current feed-in alternating-current power grid is in a system stable state, if the reactive power output of the capacitor cannot be continuously increased in the current operation mode or the terminal voltage is less than or equal to a second preset terminal voltage threshold value, determining a dynamic and static reactive power coordination control strategy under the current system overall operation voltage according to the current operation mode when the direct-current feed-in alternating-current power grid is in the system stable state.
12. The system of claim 7, further comprising:
and the preset systematized overall operation voltage threshold value adjusting unit is used for reducing the current overall operation voltage of the system according to the preset overall operation voltage adjustment step threshold value of the system if the current overall operation voltage of the system is greater than the preset allowable operation voltage threshold value, taking the adjusted overall operation voltage of the system as the preset systematized overall operation voltage threshold value, and returning to the initial operation mode adjusting unit.
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Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102074939A (en) * 2010-11-17 2011-05-25 华北电网有限公司 Online examination method of relay protection setting value based on dynamic short-circuit current
CN103094905A (en) * 2013-01-07 2013-05-08 广东电网公司电网规划研究中心 Selection method of dynamic reactive power compensation configuration point
CN103701140A (en) * 2014-01-06 2014-04-02 国家电网公司 Dynamic reactive power reserve optimization method for improving transient voltage stability of alternating-current and direct-current power grid
CN104333012A (en) * 2014-11-06 2015-02-04 国家电网公司 Multi-feed flexible DC transmission reactive power control method and device

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103296685B (en) * 2013-05-27 2015-06-10 国家电网公司 SVC (static var compensator) compensation strategy optimizing method

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102074939A (en) * 2010-11-17 2011-05-25 华北电网有限公司 Online examination method of relay protection setting value based on dynamic short-circuit current
CN103094905A (en) * 2013-01-07 2013-05-08 广东电网公司电网规划研究中心 Selection method of dynamic reactive power compensation configuration point
CN103701140A (en) * 2014-01-06 2014-04-02 国家电网公司 Dynamic reactive power reserve optimization method for improving transient voltage stability of alternating-current and direct-current power grid
CN104333012A (en) * 2014-11-06 2015-02-04 国家电网公司 Multi-feed flexible DC transmission reactive power control method and device

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
大规模直流输电馈入广东电网稳定运行的关键技术研究与应用;周保荣等;《2017年度广东省科学技术奖受理项目》;20170800;全文 *

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