CN112260283A - Power transmission section tide adjusting method and device for power system - Google Patents

Power transmission section tide adjusting method and device for power system Download PDF

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Publication number
CN112260283A
CN112260283A CN202011136562.0A CN202011136562A CN112260283A CN 112260283 A CN112260283 A CN 112260283A CN 202011136562 A CN202011136562 A CN 202011136562A CN 112260283 A CN112260283 A CN 112260283A
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power
power generation
active
sending
receiving
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CN112260283B (en
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司大军
朱欣春
李玲芳
周俊东
孙鹏
游广增
陈义宣
陈姝敏
何烨
肖友强
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Yunnan Power Grid Co Ltd
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Yunnan Power 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
    • H02J3/04—Circuit arrangements for ac mains or ac distribution networks for connecting networks of the same frequency but supplied from different sources
    • H02J3/06—Controlling transfer of power between connected networks; Controlling sharing of load between connected networks
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J3/00—Circuit arrangements for ac mains or ac distribution networks
    • H02J3/38—Arrangements for parallely feeding a single network by two or more generators, converters or transformers
    • H02J3/381—Dispersed generators
    • 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
    • H02J3/48—Controlling the sharing of the in-phase component
    • 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
    • H02J2203/00—Indexing scheme relating to details of circuit arrangements for AC mains or AC distribution networks
    • H02J2203/10—Power transmission or distribution systems management focussing at grid-level, e.g. load flow analysis, node profile computation, meshed network optimisation, active network management or spinning reserve management

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  • Power Engineering (AREA)
  • Other Liquid Machine Or Engine Such As Wave Power Use (AREA)
  • Supply And Distribution Of Alternating Current (AREA)

Abstract

The application provides a method and a device for adjusting power transmission section power flow of a power system. The method comprises the following steps: and taking the power generation node corresponding to the maximum value of the voltage phase angle as a representative node of each power generation station according to the voltage phase angles of all the power generation nodes in each power generation station, sequencing each power generation station according to the voltage phase angle of each representative node, and sequentially adjusting the active output of each power generation station according to the sequence which is most unfavorable for the stability of a power grid, so as to adjust the section tidal current until the tidal current deviation is smaller than a preset threshold value. Therefore, the influence of the power generation node on the power grid stability is reflected by the voltage phase angle, the power generation node which is the most unfavorable to the power grid stability is preferentially started and the power generation node which is the most favorable to the power grid stability is preferentially closed during the tide adjustment, the minimum section limit can be ensured, and the safety and the stability of the power grid are more favorable.

Description

Power transmission section tide adjusting method and device for power system
Technical Field
The application relates to the technical field of power system automation processing, in particular to a power system transmission section power flow adjusting method and device.
Background
When a power system is scheduled and planned by a power system scheduling and planning department, in order to ensure the safety and stability of the power system, it is necessary to ensure that a power grid can keep transient stability under a preset fault condition, and the transient stability of the power grid is generally ensured by controlling the power on a power transmission section. After some branches in the power grid are disconnected in a preset mode, the power grid is divided into two systems, the interface of the two systems is the power transmission section of the power grid, the power at the power transmission section represents the power transmitted between the two systems, and because the power transmitted at the power transmission section is too large, the power grid is possibly instable in a transient state under a certain fault condition, the section limit of the power grid at the power transmission section needs to be analyzed, namely the maximum value of the transmission power at the power transmission section under the premise that the transient state of the power grid is kept stable.
The section limit is usually determined by means of tidal current adjustment, and the main adjustment process includes: under a certain operation mode, performing transient stability analysis on the power grid under the initial power flow value, adjusting the power flow value according to an analysis result, wherein if the power grid is in a transient stable state, the power flow value of the power transmission section is increased, if the power grid is in a transient unstable state, the power flow value of the power transmission section is reduced, after the power flow value is adjusted, performing transient stability analysis on the power grid again, continuously adjusting the power flow value of the power transmission section according to the analysis result, and continuously iterating and solving the above steps to finally determine the section limit.
The sensitivity method is to calculate the power flow adjustment amount according to the target deviation and the sensitivity by calculating the sensitivity of the cross-section power flow to the active output of each generator. Generally, the active output adjustment sequence of each power generation node is different, the finally determined section limit may have a large difference, when the section limit of the power system is solved, the section tide needs to be adjusted in a mode which is most unfavorable for power grid stability, and the minimum section limit is determined as much as possible, so that the safety and stability of the power grid are ensured.
When the sensitivity method is used for tidal current adjustment, different influences of different power generation node active output adjustment sequences on the result of the section limit are not considered, and therefore the minimum section limit cannot be obtained.
Disclosure of Invention
The application provides a method and a device for adjusting power transmission section tide of a power system, which can be used for solving the technical problem that the minimum section limit cannot be obtained because different influences on the result of the section limit caused by different power generation node active output adjusting sequences are not considered when tide adjustment is carried out in the prior art.
In a first aspect, an embodiment of the present application provides a power flow adjustment method for a power transmission section of a power system, where the method includes:
carrying out load flow calculation on the power transmission section of the load flow to be adjusted to obtain a load flow result of the power transmission section; the power flow result comprises a voltage phase angle of a power generation node, active power output of the power generation node and a power flow value of each branch in the power transmission section;
dividing a preset power grid into a sending end system and a receiving end system at the position of the power transmission section according to the active power flow direction; the power transmission section comprises a plurality of branches; the power grid comprises a plurality of power generation stations; the power plant comprises a plurality of power generation nodes;
determining an initial tidal current value of the power transmission section according to the tidal current values of all the branches;
determining a maximum voltage phase angle from the voltage phase angles of all power generation nodes in the power station, and taking the power generation node corresponding to the maximum voltage phase angle as a representative node of the power station;
determining a power flow adjustment amount according to a preset target power flow value and the initial power flow value, and determining a sending end unit adjustment amount of a sending end system and a receiving end unit adjustment amount of a receiving end system according to the power flow adjustment amount;
if the tidal current adjustment quantity is larger than zero, sequentially adjusting the active output of each sending end power station according to the adjustment quantity of the sending end unit, the active output of each power generation node in the sending end power station of the sending end system and the maximum active output of each power generation node in the sequence from large to small of the voltage phase angle of the representative node; the active output of the sending-end power station is the sum of the active outputs of all power generation nodes in the sending-end power station;
according to the receiving end unit adjustment quantity, the active output of each power generation node in the receiving end power station of the receiving end system and the maximum active output of each power generation node, sequentially adjusting the active output of each receiving end power station according to the sequence of the voltage phase angle of the representative node from small to large; the active output of the receiving-end power station is the sum of the active outputs of all power generation nodes in the receiving-end power station;
determining an updated tidal current value after the tidal current of the power transmission section is adjusted according to the adjusted active output of all the power stations;
determining a tidal current deviation according to the target tidal current value and the updated tidal current value;
and if the power flow deviation is greater than or equal to a preset threshold value, setting the updated power flow value as an initial power flow value, returning to the step of determining the power flow adjustment amount until the power flow deviation is less than the preset threshold value, and finishing the power flow adjustment of the power transmission section.
In an implementation manner of the first aspect, the dividing, at the power transmission section, a preset power grid into a sending-end system and a receiving-end system according to an active power flow direction includes:
dividing a preset power grid into two systems at the power transmission section;
and according to the active power flow direction, taking the system which sends out the power in the two systems as a sending end system, and taking the system which flows in the power in the two systems as a receiving end system.
In an implementation manner of the first aspect, the power flow adjustment amount, the sending end unit adjustment amount, and the receiving end unit adjustment amount are determined by:
Figure BDA0002736913660000021
wherein Δ P is the power flow adjustment amount, P1Is the target tidal current value, P0Is the initial tidal current value, Δ PmFor the adjustment of the sending end unit, Δ PnAnd adjusting the quantity of the receiving end unit.
In an implementation manner of the first aspect, the sequentially adjusting the active power output of each sending-end power station is implemented by:
sequencing all the transmitting-end power stations according to the sequence of the voltage phase angles of the representative nodes from large to small to obtain a transmitting-end power station sequence;
for a first sending-end power station in the sending-end power station sequence, determining an active regulating value of a first power generation node according to the sending-end unit regulating quantity, the active output of the first power generation node in the first sending-end power station and the maximum active output of the first power generation node;
if the active regulating value of the first power generation node is not equal to the adjustment value of the sending end unit, determining the active regulating value of the next power generation node according to a first difference value between the adjustment value of the sending end unit and the active regulating value of the first power generation node, the active output of the next power generation node in the first sending end power station and the maximum active output of the next power generation node;
if the sum of the active adjustment values of all the power generation nodes in the first sending-end power station is not equal to the sending-end unit adjustment amount, the active adjustment values of all the power generation nodes in the second sending-end power station in the sending-end power station sequence are continuously determined until the sum of the active adjustment values of all the power generation nodes adjusted in the sending-end power station sequence is equal to the sending-end unit adjustment amount, and the active output of the corresponding power generation node is adjusted according to the adjusted active adjustment values of all the power generation nodes in the sending-end power station sequence.
In an implementation manner of the first aspect, the sequentially adjusting the active power output of each receiving-end power station is implemented by:
sequencing all receiving-end power stations according to the sequence of voltage phase angles of the representative nodes from small to large to obtain a receiving-end power station sequence;
for a first receiving-end power station in the receiving-end power station sequence, determining an active regulation value of a first receiving-end power generation node according to the receiving-end unit adjustment quantity, the active output of the first receiving-end power generation node in the first receiving-end power station and the maximum active output of the first receiving-end power generation node;
if the active regulating value of the first receiving end power generation node is not equal to the receiving end unit regulating value, determining the active regulating value of the next power generation node according to the difference value between the receiving end unit regulating value and the active regulating value of the first receiving end power generation node, the active output of the next power generation node in the first receiving end power station and the maximum active output of the next power generation node;
if the sum of the active adjustment values of all the power generation nodes in the first receiving-end power station is not equal to the receiving-end unit adjustment amount, the active adjustment values of all the power generation nodes in a second receiving-end power station in the receiving-end power station sequence are continuously determined until the sum of the active adjustment values of all the power generation nodes adjusted in the receiving-end power station sequence is equal to the receiving-end unit adjustment amount, and the active output of the corresponding power generation node is adjusted according to the adjusted active adjustment values of all the power generation nodes in the receiving-end power station sequence.
In an implementation manner of the first aspect, the method further includes:
if the tidal current adjustment quantity is smaller than zero, sequentially adjusting the active output of each sending end power station according to the adjustment quantity of the sending end unit, the active output of each power generation node in the sending end power station of the sending end system and the maximum active output of each power generation node in the sequence from small voltage phase angle to large voltage phase angle of the representative node; the active output of the sending-end power station is the sum of the active outputs of all power generation nodes in the sending-end power station;
according to the receiving end unit adjustment quantity, the active output of each power generation node in the receiving end power station of the receiving end system and the maximum active output of each power generation node, the active output of each receiving end power station is sequentially adjusted according to the sequence of voltage phase angles of the representative nodes from large to small; the active output of the receiving-end power station is the sum of the active outputs of all power generation nodes in the receiving-end power station.
In a second aspect, an embodiment of the present application provides an apparatus for adjusting a power flow of a power transmission section of a power system, where the apparatus includes:
the preprocessing unit is used for carrying out load flow calculation on the power transmission section of the load flow to be adjusted to obtain a load flow result of the power transmission section; the power flow result comprises a voltage phase angle of a power generation node, active power output of the power generation node and a power flow value of each branch in the power transmission section; dividing a preset power grid into a transmitting end system and a receiving end system according to the active power flow direction at the power transmission section; the power transmission section comprises a plurality of branches; the power grid comprises a plurality of power generation stations; the power plant comprises a plurality of power generation nodes; (ii) a Determining an initial tidal current value of the power transmission section according to the tidal current values of all the branches;
the processing unit is used for determining the maximum voltage phase angle from the voltage phase angles of all the power generation nodes in the power station and taking the power generation node corresponding to the maximum voltage phase angle as a representative node of the power station; determining a power flow adjustment amount according to a preset target power flow value and the initial power flow value, and determining a sending end unit adjustment amount of a sending end system and a receiving end unit adjustment amount of a receiving end system according to the power flow adjustment amount;
the first adjusting unit is used for sequentially adjusting the active output of each sending-end power station according to the adjustment quantity of the sending-end unit, the active output of each power generation node in the sending-end power station of the sending-end system and the maximum active output of each power generation node according to the sequence of the voltage phase angle of the representative node from large to small if the power flow adjustment quantity is larger than zero; the active output of the sending-end power station is the sum of the active outputs of all power generation nodes in the sending-end power station; according to the adjustment quantity of the receiving end unit, the active output of each power generation node in the receiving end power station of the receiving end system and the maximum active output of each power generation node, the active output of each receiving end power station is sequentially adjusted according to the sequence of the voltage phase angle of the representative node from small to large; the active output of the receiving-end power station is the sum of the active outputs of all power generation nodes in the receiving-end power station;
the verification unit is used for determining an updated tidal current value after the tidal current of the power transmission section is adjusted according to the adjusted active output of all the power stations; determining a tidal current deviation according to the target tidal current value and the updated tidal current value; and if the power flow deviation is larger than or equal to a preset threshold value, setting the updated power flow value as an initial power flow value, and returning to the step of determining the power flow adjustment amount until the power flow deviation is smaller than the preset threshold value, and finishing the power flow adjustment of the power transmission section.
In an implementation manner of the second aspect, the preprocessing unit is specifically configured to:
dividing a preset power grid into two systems at the power transmission section;
and according to the active power flow direction, taking the system which sends out the power in the two systems as a sending end system, and taking the system which flows in the power in the two systems as a receiving end system.
In an implementation manner of the second aspect, the power flow adjustment amount, the sending end unit adjustment amount, and the receiving end unit adjustment amount are determined by:
Figure BDA0002736913660000041
wherein Δ P is the power flow adjustment amount, P1Is the target tidal current value, P0Is the initial tidal current value, Δ PmFor the adjustment of the sending end unit, Δ PnAnd adjusting the quantity of the receiving end unit.
In an implementation manner of the second aspect, the first adjusting unit is specifically configured to:
sequencing all the transmitting-end power stations according to the sequence of the voltage phase angles of the representative nodes from large to small to obtain a transmitting-end power station sequence;
for a first sending-end power station in the sending-end power station sequence, determining an active regulating value of a first power generation node according to the sending-end unit regulating quantity, the active output of the first power generation node in the first sending-end power station and the maximum active output of the first power generation node;
if the active regulating value of the first power generation node is not equal to the adjustment value of the sending end unit, determining the active regulating value of the next power generation node according to a first difference value between the adjustment value of the sending end unit and the active regulating value of the first power generation node, the active output of the next power generation node in the first sending end power station and the maximum active output of the next power generation node;
if the sum of the active adjustment values of all the power generation nodes in the first sending-end power station is not equal to the sending-end unit adjustment amount, the active adjustment values of all the power generation nodes in the second sending-end power station in the sending-end power station sequence are continuously determined until the sum of the active adjustment values of all the power generation nodes adjusted in the sending-end power station sequence is equal to the sending-end unit adjustment amount, and the active output of the corresponding power generation node is adjusted according to the adjusted active adjustment values of all the power generation nodes in the sending-end power station sequence.
In an implementation manner of the second aspect, the first adjusting unit is specifically configured to:
sequencing all receiving-end power stations according to the sequence of voltage phase angles of the representative nodes from small to large to obtain a receiving-end power station sequence;
for a first receiving-end power station in the receiving-end power station sequence, determining an active regulation value of a first receiving-end power generation node according to the receiving-end unit adjustment quantity, the active output of the first receiving-end power generation node in the first receiving-end power station and the maximum active output of the first receiving-end power generation node;
if the active regulating value of the first receiving end power generation node is not equal to the receiving end unit regulating value, determining the active regulating value of the next power generation node according to the difference value between the receiving end unit regulating value and the active regulating value of the first receiving end power generation node, the active output of the next power generation node in the first receiving end power station and the maximum active output of the next power generation node;
if the sum of the active adjustment values of all the power generation nodes in the first receiving-end power station is not equal to the receiving-end unit adjustment amount, the active adjustment values of all the power generation nodes in a second receiving-end power station in the receiving-end power station sequence are continuously determined until the sum of the active adjustment values of all the power generation nodes adjusted in the receiving-end power station sequence is equal to the receiving-end unit adjustment amount, and the active output of the corresponding power generation node is adjusted according to the adjusted active adjustment values of all the power generation nodes in the receiving-end power station sequence.
In an implementable manner of the second aspect, the apparatus further comprises:
the second adjusting unit is used for sequentially adjusting the active output of each sending-end power station according to the adjustment quantity of the sending-end unit, the active output of each power generation node in the sending-end power station of the sending-end system and the maximum active output of each power generation node according to the sequence of the voltage phase angle of the representative node from small to large if the flow adjustment quantity is smaller than zero; the active output of the sending-end power station is the sum of the active outputs of all power generation nodes in the sending-end power station;
according to the receiving end unit adjustment quantity, the active output of each power generation node in the receiving end power station of the receiving end system and the maximum active output of each power generation node, the active output of each receiving end power station is sequentially adjusted according to the sequence of voltage phase angles of the representative nodes from large to small; the active output of the receiving-end power station is the sum of the active outputs of all power generation nodes in the receiving-end power station.
Therefore, the influence of the power generation node on the stability of the power grid is reflected through the voltage phase angle of the power generation node in the power grid, the power generation node with the largest voltage phase angle in each power station is used as the representative node of the power station, the power stations are sequenced according to the voltage phase angle of each representative node, and the active output of each power station is sequentially regulated according to the sequence which is most unfavorable for the stability of the power grid, namely, the power flow is regulated. The tide adjusting method can ensure that the minimum, namely the most conservative section limit is obtained, and is more favorable for the safety and the stability of a power grid.
Drawings
Fig. 1 is a schematic flow chart corresponding to a power transmission section flow adjustment method of an electric power system according to an embodiment of the present application;
fig. 2 is a schematic structural diagram of a sending-end system and a receiving-end system provided in an embodiment of the present application;
fig. 3 is a schematic structural diagram of a power flow adjustment device for a power transmission section of a power system according to an embodiment of the present application.
Detailed Description
To make the objects, technical solutions and advantages of the present application more clear, embodiments of the present application will be described in further detail below with reference to the accompanying drawings.
In order to solve the problems in the prior art, embodiments of the present application provide a power transmission section flow adjustment method for an electric power system, and specifically, the method is used for solving the problem that a minimum section limit cannot be obtained because different active output adjustment sequences of power generation nodes cannot cause different influences on a section limit result when flow adjustment is performed in the prior art. Fig. 1 is a schematic flow chart corresponding to a power flow adjustment method for a power transmission section of an electric power system according to an embodiment of the present application. The method specifically comprises the following steps:
step 101, carrying out load flow calculation on a power transmission section of the load flow to be adjusted to obtain a load flow result of the power transmission section.
Step 102, dividing a preset power grid into a transmitting end system and a receiving end system at a power transmission section according to an active power flow direction.
And 103, determining an initial tidal current value of the power transmission section according to the tidal current values of all the branches.
And step 104, determining the maximum voltage phase angle from the voltage phase angles of all the power generation nodes in the power station, and taking the power generation node corresponding to the maximum voltage phase angle as a representative node of the power station.
And 105, determining a power flow adjustment amount according to a preset target power flow value and an initial power flow value, and determining a sending end unit adjustment amount of a sending end system and a receiving end unit adjustment amount of a receiving end system according to the power flow adjustment amount.
And step 106, if the power flow adjustment quantity is larger than zero, sequentially adjusting the active output of each sending end power station according to the adjustment quantity of the sending end unit, the active output of each power generation node in the sending end power station of the sending end system and the maximum active output of each power generation node in the order from large to small of the voltage phase angle of the representative node.
And 107, sequentially adjusting the active output of each receiving-end power station according to the adjustment quantity of the receiving-end unit, the active output of each power generation node in the receiving-end power station of the receiving-end system and the maximum active output of each power generation node in the order from small to large of the voltage phase angle of the representative node.
And step 108, determining an updated tidal current value after the tidal current of the power transmission section is adjusted according to the adjusted active output of all the power stations.
And step 109, determining the tidal current deviation according to the target tidal current value and the updated tidal current value.
Step 110, if the power flow deviation is greater than or equal to a preset threshold, executing step 111: setting the updated power flow value as an initial power flow value, and returning to the step 105 of determining the power flow adjustment amount; and finishing the power flow adjustment of the power transmission section until the power flow deviation is smaller than a preset threshold value.
Specifically, in step 101, a power transmission section of a power flow to be adjusted is determined as required, and a power flow result of the power transmission section includes a voltage phase angle of a power generation node, an active power output of the power generation node, and a power flow value of each branch in the power transmission section. Specifically, load flow calculation software, such as PDS-BPA software, may be used to calculate the load flow of the power transmission section, or the load flow of the power transmission section may be directly calculated by using a formula, which is not limited specifically.
In step 102, a preset power grid represents a plurality of power transmission lines between two areas, a power transmission section of the power grid comprises a plurality of branches, the power grid comprises a plurality of power generation stations, and each power generation station comprises a plurality of power generation nodes. The power generation node corresponds to a power generation unit in a power station, and refers to a node with actual active output greater than zero or maximum active output greater than zero, and the node with actual active output equal to zero is also included in the embodiment of the present application, except for a balance node. That is, one genset in the power plant represents one power generation node.
The power transmission section naturally divides the power grid into a transmitting end system and a receiving end system, and as shown in fig. 2, the power grid is a schematic structural diagram of the transmitting end system and the receiving end system provided by the embodiment of the present application. The sending end system and the receiving end system are divided by the following modes:
and dividing a preset power grid into two systems at the position of a power transmission section.
And according to the active power flow direction, a system which sends out power in the two systems is used as a sending end system, and a system which flows in power in the two systems is used as a receiving end system.
It should be noted that, in the power grid, the power station located in the sending end system is the sending end power station, and the power station located in the receiving end system is the receiving end power station.
In step 103, the sum of the tidal current values of all the branches is used as the initial tidal current value of the power transmission section.
In step 104, for each power generation station, the power generation station includes one or more power generation nodes, each power generation node has a corresponding voltage phase angle, a maximum voltage phase angle is determined from the voltage phase angles of the power generation nodes, and the power generation node corresponding to the maximum voltage phase angle is used as a representative node of the power generation station. And respectively determining the representative node of each power station aiming at all the power stations in the power grid.
Therefore, by adopting the method, the influence of the power generation node on the stability of the power grid is reflected by using the voltage phase angle of the power generation node, the power generation node which is the most unfavorable to the stability of the power grid and the power generation node which is the most favorable to the stability of the power grid are accurately judged, and a foundation is laid for the subsequent power flow adjustment.
In step 105, the power flow adjustment amount, the sending end unit adjustment amount and the receiving end unit adjustment amount are determined by formula (1):
Figure BDA0002736913660000071
in the formula (1), Δ P is the power flow adjustment amount, P1Is the target tidal current value, P0Is the initial tidal current value, Δ PmFor adjustment of sending-end unit, Δ PnAnd adjusting the quantity for the receiving end unit.
In step 106, the active output of the sending-end power station refers to the sum of the active outputs of all power generation nodes in the sending-end power station. It should be noted that adjusting the active output of the sending-end power station is to sequentially adjust the active output of each power generation node in each sending-end power station. Specifically, if the power flow adjustment amount Δ P is greater than zero, the active power output of each sending-end power station is sequentially adjusted by:
and sequencing all the transmitting-end power stations according to the sequence of the voltage phase angles of the representative nodes from large to small to obtain a transmitting-end power station sequence.
And aiming at a first sending end power station in the sending end power station sequence, determining an active regulating value of a first power generation node according to the adjustment quantity of a sending end unit, the active output of the first power generation node in the first sending end power station and the maximum active output of the first power generation node.
And if the active regulating value of the first power generation node is not equal to the adjustment value of the sending end unit, determining the active regulating value of the next power generation node according to a first difference value between the adjustment value of the sending end unit and the active regulating value of the first power generation node, the active output of the next power generation node in the first sending end power station and the maximum active output of the next power generation node.
And if the sum of the active adjustment values of all the power generation nodes in the first sending-end power station is not equal to the adjustment amount of the sending-end unit, continuously determining the active adjustment value of each power generation node in the second sending-end power station in the sending-end power station sequence until the sum of the adjusted active adjustment values of all the power generation nodes in the sending-end power station sequence is equal to the adjustment amount of the sending-end unit, and adjusting the active output of the corresponding power generation node according to the adjusted active adjustment value of each power generation node in the sending-end power station sequence.
In the process of adjusting the active output of the power generation node at the transmitting end, if a plurality of power generation nodes exist in each power generation station at the transmitting end, the adjusting sequence can perform active adjustment on the power generation node at the transmitting end according to the sequence of the voltage phase angle from large to small.
In order to more clearly illustrate the active power output adjustment process of the transmitting-end power station, the following description is taken in conjunction with specific formulas.
Assuming that M sending-end power stations exist in a sending-end system, sequencing the M sending-end power stations according to the sequence of voltage phase angles of M representative nodes from large to small to obtain a sending-end power station sequence Sm＝{Sm,1，Sm,2……Sm,MIn which S ism,1A transmitting station with the largest voltage phase angle, Sm,MThe terminal power station with the smallest voltage phase angle. Assuming that there are k power generation nodes in each transmitting-end power generation station, the power generation nodes of each transmitting-end power generation station in the transmitting-end power generation station sequence are sorted in the order of the voltage phase angles from large to small, and then the whole transmitting-end power generation node sequence S ═ { S ═ can be obtained1，S2，S3,……SMk}。
For the first power generation node S1The deviation between the adjustable range and the adjustment quantity of the sending end unit is determined by a formula (2):
ΔP1＝ΔPm-(Pmax,1-P1) Formula (2)
In the formula (2), Δ P1Is the deviation, delta P, of the adjustable range of the first power generation node from the adjustment of the sending end unitmFor adjustment of sending-end unit, Pmax,1Is the maximum active output, P, of the first power generation node1The active output of the first power generation node.
If Δ P1Less than or equal to zero, then P ismax,1And Δ P1As the first power generation node S1The adjusted target active value is the target active value minus the active power output P1The obtained difference value is the active adjustment value delta P1,1According to the active regulation value, a first power generation node S in a first transmitting-end power station1And after the active power output is adjusted, the active power adjustment of the sending-end power station is finished. It should be noted that, at this time, the active adjustment value of the first power generation node is equal to the adjustment amount of the sending-end unit, it is indicated that the active output of the first power generation node is adjusted to meet the requirement of sending-end tidal current adjustment, and the active adjustment of the sending-end power station is finished after the first power generation node is adjusted.
If Δ P1If greater than zero, P will bemax,1As a first power generation node S1The adjusted target active value is the target active value minus the active power output P1The obtained difference value is the active adjustment value delta P1,1For the first power generation node S1After the active power output is adjusted, the second power generation node S is continuously adjusted2Active power output of (1). It should be noted that, at this time, the active adjustment value of the first power generation node is not equal to the adjustment amount of the sending-end unit, which indicates that only adjusting the active output of the first power generation node cannot meet the requirement of sending-end tidal current adjustment, and the next power generation node needs to be continuously adjusted after the first power generation node is adjusted.
And the analogy is carried out until the active regulation values of the first j power generation nodes in the power generation node sequenceAnd Δ P1,1+ΔP1,2+……ΔP1,jEqual to the adjustment quantity delta P of the sending end unitmJ is the number of the power generation nodes of the transmitting end for active power regulation, and j is an integer which is greater than or equal to 1 and less than or equal to Mk; mk is the total number of the sending end power generation nodes. And correspondingly adjusting the active output of each power generation node according to the active adjustment value of each power generation node, and finishing the active adjustment of the power transmission end power station. It should be noted that it is not necessary that each power generation node of each power generation station in the sending-end power generation station sequence is adjusted, and the adjustment can be finished as long as the sum of the active adjustment values of the adjusted power generation nodes is equal to the adjustment amount of the sending-end unit.
In step 107, the active output of the receiving-end power station refers to the sum of the active outputs of all power generation nodes in the receiving-end power station. It should be noted that adjusting the active output of the receiving-end power station is to sequentially adjust the active output of each power generation node in each receiving-end power station. Specifically, if the power flow adjustment amount Δ P is greater than zero, the active power output of each receiving-end power station is sequentially adjusted by:
and sequencing all receiving-end power stations according to the sequence of the voltage phase angles of the representative nodes from small to large to obtain a receiving-end power station sequence.
And aiming at a first receiving-end power station in the receiving-end power station sequence, determining an active regulating value of a first receiving-end power generation node according to the adjusting quantity of a receiving-end unit, the active output of the first receiving-end power generation node in the first receiving-end power station and the maximum active output of the first receiving-end power generation node.
And if the active regulating value of the first receiving end generating node is not equal to the regulating value of the receiving end unit, determining the active regulating value of the next generating node according to the difference value of the regulating value of the receiving end unit and the active regulating value of the first receiving end generating node, the active output of the next generating node in the first receiving end power station and the maximum active output of the next generating node.
And if the sum of the active regulating values of all the generating nodes in the first receiving end power station is not equal to the adjusting amount of the receiving end unit, continuously determining the active regulating value of each generating node in the second receiving end power station in the receiving end power station sequence until the sum of the adjusted active regulating values of all the generating nodes in the receiving end power station sequence is equal to the adjusting amount of the receiving end unit, and adjusting the active output of the corresponding generating node according to the adjusted active regulating value of each generating node in the receiving end power station sequence.
In the process of adjusting the active output of the receiving-end power generation node, if a plurality of power generation nodes exist in each receiving-end power generation station, the adjusting sequence can perform active adjustment on the receiving-end power generation node according to the sequence of the voltage phase angle from small to large.
In order to more clearly illustrate the active power output regulation process of the receiving-end power station, the following description is taken in conjunction with a specific formula.
Assuming that N receiving-end power stations exist in a receiving-end system, sequencing the N receiving-end power stations according to the sequence of voltage phase angles of the N representative nodes from small to large to obtain a receiving-end power station sequence Sn＝{Sn,1，Sn,2……Sn,NIn which S isn,1A receiving-end power station with the smallest voltage phase angle, Sn,NThe receiving-end power station with the largest voltage phase angle. Assuming that there are t power generation nodes in each receiving-end power generation station, and for each receiving-end power generation station in the receiving-end power generation station sequence, the power generation nodes are sorted in the order of the voltage phase angles from small to large, and then the whole receiving-end power generation node sequence S ═ { S ═ can be obtained1，S2，S3,……SNt}。
For the first power generation node S1And the deviation between the adjustable range and the adjustment quantity of the receiving end unit is determined by a formula (3):
ΔP1＝ΔPn+P1formula (3)
In the formula (3), Δ P1Is the deviation of the adjustable range of the first power generation node and the adjustment quantity of the receiving end unit, delta PnFor regulating the receiving-end unit, P1The active output of the first power generation node.
If Δ P1Greater than or equal to zero, then Δ P will be1As a first power generation node S1Regulated target active powerValue, target active value minus active power P1The obtained difference value is the active adjustment value delta P1,1According to the active regulation value, the first power generation node S1And after the active power output is regulated, the active power regulation of the receiving-end power station is finished. It should be noted that, at this time, the active adjustment value of the first power generation node is equal to the adjustment amount of the receiving-end unit, it is indicated that the active output of the first power generation node is adjusted to meet the receiving-end tidal current adjustment requirement, and the active adjustment of the receiving-end power station is finished after the first power generation node is adjusted.
If Δ P1If the voltage is less than zero, the zero is taken as the first power generation node S1The adjusted target active value is the target active value minus the active power output P1The obtained difference value is the active adjustment value delta P1,1For the first power generation node S1After the active power output is adjusted, the second power generation node S is continuously adjusted2Active power output of (1). It should be noted that, at this time, the active adjustment value of the first power generation node is not equal to the adjustment amount of the receiving-end unit, which indicates that only adjusting the active output of the first power generation node cannot meet the receiving-end tidal current adjustment requirement, and the next power generation node needs to be continuously adjusted after the first power generation node is adjusted.
And analogizing in turn until the sum delta P of the active adjustment values of all the power generation nodes1,1+ΔP1,2+……ΔP1,iEqual to the adjustment quantity delta P of the receiving end unitnWherein i is the number of receiving end power generation nodes for active power regulation, and i is an integer greater than or equal to 1 and less than or equal to Nt; nt is the total number of receiving end power generation nodes. And correspondingly adjusting the active output of each power generation node according to the active adjustment value of each power generation node, and ending the active adjustment of the receiving-end power station. It should be noted that it is not necessary that each power generation node of each power generation station in the receiving-end power generation station sequence is adjusted, and the adjustment can be finished as long as the sum of the active adjustment values of the adjusted power generation nodes is equal to the adjustment amount of the receiving-end unit.
Before performing step 108, the following steps are also performed:
and if the tidal current adjustment quantity is less than zero, sequentially adjusting the active output of each transmitting end power station according to the adjustment quantity of the transmitting end unit, the active output of each generating node in the transmitting end power station of the transmitting end system and the maximum active output of each generating node in the sequence from small to large of the voltage phase angle of the representative node. The active output of the sending-end power station is the sum of the active outputs of all power generation nodes in the sending-end power station.
And sequentially adjusting the active output of each receiving-end power station according to the adjustment quantity of the receiving-end unit, the active output of each power generation node in the receiving-end power station of the receiving-end system and the maximum active output of each power generation node in the order from large to small of the voltage phase angle of the representative node. The active output of the receiving-end power station is the sum of the active outputs of all power generation nodes in the receiving-end power station.
Specifically, when the tidal current adjustment amount Δ P is less than zero, the adjustment amount of the sending-end unit is also less than zero, the active output of the sending-end power station when the tidal current adjustment amount Δ P is less than zero can be adjusted by referring to the active processing and adjusting process of the receiving-end power station when the tidal current adjustment amount Δ P is greater than zero, that is, referring to formula (3), until the sum of the active adjustment values of the first j power generation nodes of the sending-end power station is equal to the adjustment amount of the sending-end unit, and the sending-end tidal current adjustment is finished. Wherein j is an integer greater than or equal to 1 and less than or equal to Mk; mk is the total number of the sending end power generation nodes.
When the tidal current adjustment quantity delta P is less than zero, the adjustment quantity of the receiving end unit is greater than zero, the active power output of the receiving end power station when the tidal current adjustment quantity delta P is less than zero can be adjusted by referring to the active processing and adjusting process of the sending end power station when the tidal current adjustment quantity delta P is greater than zero, namely referring to a formula (2), until the sum of the active adjustment values of the first i power generation nodes of the receiving end power station is equal to the adjustment quantity of the receiving end unit, and the receiving end tidal current adjustment is finished. Wherein i is an integer greater than or equal to 1 and less than or equal to Nt; nt is the total number of receiving end power generation nodes.
By adopting the method to carry out the tidal current adjustment, when the section tidal current needs to be increased, the power generation nodes with the stability of the power grid and the receiving end are preferentially increased, when the section tidal current needs to be reduced, the power generation nodes with the stability of the power grid and the receiving end are preferentially decreased, and then the tidal current adjustment is carried out in the direction which is most unfavorable to the stability of the power grid. The tide adjusting method can ensure that the minimum, namely the most conservative section limit is obtained, and is more favorable for the safety and the stability of a power grid.
And step 108, carrying out load flow calculation on the power transmission section again according to the adjusted active power output of all the power stations to obtain an updated load flow value of the power transmission section after load flow adjustment.
In step 109, the power flow deviation is determined by formula (4):
ΔP'＝P1-P'0formula (4)
In the formula (4), Δ P' is the power flow deviation, P1Is a target tidal stream value, P'0To update the tidal current value.
In steps 110 and 111, judging whether the power flow deviation delta P ' is smaller than a preset threshold value, and if the power flow deviation delta P ' is larger than or equal to the preset threshold value, updating the power flow value P '0Setting the initial tidal current value, returning to the step 105 of determining the tidal current adjustment amount, performing tidal current adjustment again, calculating tidal current deviation again until the tidal current deviation is smaller than a preset threshold value, and finishing tidal current adjustment on the power transmission section.
In order to more clearly illustrate steps 101 to 111, the following is illustrated by a specific example.
The preset power system provided by the embodiment of the application is simulated by adopting PDS-BPA software, the preset power system is divided into a transmitting end system and a receiving end system by a preset power transmission section according to the active power flow direction, two branches, namely a branch 1 and a branch 2, are arranged at the power transmission section, the transmitting end system comprises three power stations of a power supply A, a power supply B and a power supply C, power with the power of 2 multiplied by 177.3 equal to 354.6MW is transmitted to the receiving end system through the two branches, and the receiving end system comprises two power stations of a power supply D and a power supply E. Wherein, the power supply A comprises two power generation nodes, A1G and A2G respectively; power source B includes two power generation nodes, B1G and B2G; the power source C includes two power generation nodes, C1G and C2G; the power supply D comprises two power generation nodes, namely D1G and D2G, and D1G is a balancing machine; the power source E includes a power generation node, i.e., E1G. The maximum active output of each power generation node in the power supply A, the power supply B, the power supply C, the power supply E and the power supply D is 80 MW.
In order to calculate the limits of presetting two branches N-1 (1 of them is disconnected) of the power system at the transmission section, the power flow needs to be increased to 410 MW. That is, the initial tidal current value P0 is 354.6MW, and the target tidal current value P1The power flow adjustment quantity delta P is 410MW, and the power flow adjustment quantity delta P is 410MW-354.6MW which is 55.4 MW.
The power flow calculation is performed on a preset power system, and the power generation nodes in each power station of the power system, the active power output of each power generation node, and the voltage phase angle information of each power generation node are shown in table 1.
Table 1: an example of active output, voltage phase angle of a power generation node and power generation nodes in power generation stations of a power system
Figure BDA0002736913660000101
In the power station a, the voltage phase angle of the power supply A1G is the largest, the power supply A1G is the representative node of the power station a, and by analogy, the power supply B1G is the representative node of the power station B, the power supply C1G is the representative node of the power station C, the power supply D2G is the representative node of the power station D, and the power supply E1G is the representative node of the power station E.
Determining the adjustment quantity delta P of the sending end unit according to the tidal current adjustment quantity delta P being 55.4MWmIs 55.4MW, the adjustment quantity delta P of the receiving end unitnIt was-55.4 MW. Due to the power flow adjustment quantity delta P being 55.4MW>And 0, adjusting the active output of the corresponding power station in the active output adjusting process of the sending end power station and the receiving end power station according to the condition that the tidal current adjustment quantity delta P is larger than zero. The specific process is as follows:
sequencing the power stations at the sending end according to the voltage phase angles of the representative nodes from large to small, and sequencing the power stations at the sending end SmPower supply B, power supply C, power supply a }; the receiving-end power stations are sorted from small to large according to the voltage phase angle of the representative node, and the receiving-end power station sequence SnPower D, power E. Sequence of sending-end generating nodesThe power source B1G, the power source B2G, the power source C1G, the power source C2G, the power source A1G, and the power source A2G, and the receiving-side power generation node sequence is { the power source D1G, the power source D2G, the power source E1G }.
The first power generation node B1G of the sending-end power station is full of capacity and cannot be adjusted upwards.
For the second power generation node B2G of the sending-end power station, the deviation delta P between the adjustable range and the adjustment quantity of the sending-end unit2＝55.4-(80-50)＝25.4>And 0, taking 80MW as a target active power value of the second power generation node B2G, wherein the active power regulation value is 80-50 to 30MW, that is, the active power output of B2G is adjusted to 30MW, and is adjusted to 80MW from the original 50 MW.
The third power generation node C1G of the sending-end power station is full of capacity and cannot be adjusted upwards.
Aiming at the fourth power generation node C2G of the sending-end power station, the deviation delta P between the adjustable range and the adjustment quantity of the sending-end unit4＝25.4-(80-0)＝-54.6<And 0, taking 80-54.6-25.4 MW as the target active value of the fourth power generation node C2G, namely, adjusting the active output of C2G by 25.4MW, and ending the active regulation of the transmitting-end power station.
The first power generation node D1G of the receiving-end power station is a balancing machine and is not considered. Aiming at the second power generation node D2G of the receiving-end power station, the deviation delta P between the adjustable range and the adjustment quantity of the receiving-end unit2＝-55.4+50＝-5.4<00, taking 0MW as a target active value of the second power generation node D2G, where the active adjustment value is 0-50 to-50 MW, that is, the active output of D2G is adjusted to 50MW, and is adjusted to 0MW from the original 50MW, and at this time, the active output of the third power generation node E1G of the receiving-end power station needs to be continuously adjusted.
Aiming at the third power generation node E1G of the receiving-end power station, the deviation delta P between the adjustable range and the adjustment quantity of the receiving-end unit3＝-5.4+50＝44.6>And 0, taking 44.6MW as a target active value of the third power generation node E1G, and taking an active regulation value of 44.6-50 MW to-5.4 MW, namely, regulating the active output of E1G to 5.4MW from the original 50MW to 44.6MW, and ending the active regulation of the receiving-end power station.
And recalculating the power flow of the power transmission section according to the active power output adjusted by each power generation node to obtain an updated power flow value of 408.3MW, a power flow deviation of 410MW-408.3 MW-1.7 MW, and an absolute value greater than a preset threshold value of 1MW, so that power flow adjustment needs to be performed again. And repeating the calculation of the steps, and finally adjusting the active output to 27.1MW from 25.4W for the fourth power generation node C2G of the transmitting-end power station and to 42.9MW from 44.6MW for the second power generation node D2G of the receiving-end power station.
And recalculating the power flow of the power transmission section again according to the adjusted active output to obtain an updated power flow value of 410MW, wherein the power flow deviation is 410 MW-0 MW, the absolute value is less than a preset threshold value of 1MW, and the power flow adjustment is finished.
The following are embodiments of the apparatus of the present application that may be used to perform embodiments of the method of the present application. For details which are not disclosed in the embodiments of the apparatus of the present application, reference is made to the embodiments of the method of the present application.
Fig. 3 schematically illustrates a structural diagram of a power system transmission profile power flow adjustment device provided by an embodiment of the present application. As shown in fig. 3, the apparatus has a function of implementing the power transmission section flow adjustment method of the power system, and the function may be implemented by hardware, or may be implemented by hardware executing corresponding software. The apparatus may include: a preprocessing unit 301, a processing unit 302, a first adjusting unit 303 and a verifying unit 304.
The preprocessing unit 301 is configured to perform power flow calculation on a power transmission section of a power flow to be adjusted to obtain a power flow result of the power transmission section; the power flow result comprises a voltage phase angle of a power generation node, active power output of the power generation node and a power flow value of each branch in a power transmission section; dividing a preset power grid into a transmitting end system and a receiving end system at a power transmission section according to the active power flow direction; the power transmission section comprises a plurality of branches; the power grid comprises a plurality of power generation stations; the power generation station comprises a plurality of power generation nodes; (ii) a And determining an initial tidal current value of the power transmission section according to the tidal current values of all the branches.
The processing unit 302 is configured to determine a maximum voltage phase angle from voltage phase angles of all power generation nodes in the power plant, and use a power generation node corresponding to the maximum voltage phase angle as a representative node of the power plant; and determining a power flow adjustment amount according to a preset target power flow value and an initial power flow value, and determining a sending end unit adjustment amount of a sending end system and a receiving end unit adjustment amount of a receiving end system according to the power flow adjustment amount.
A first adjusting unit 303, configured to, if the power flow adjustment amount is greater than zero, sequentially adjust the active output of each sending-end power station according to the sending-end unit adjustment amount, the active output of each power generation node in the sending-end power station located in the sending-end system, and the maximum active output of each power generation node, in an order from large to small of the voltage phase angle of the representative node; the active output of the sending-end power station is the sum of the active outputs of all power generation nodes in the sending-end power station; according to the adjustment quantity of the receiving end unit, the active output of each power generation node in the receiving end power station of the receiving end system and the maximum active output of each power generation node, the active output of each receiving end power station is sequentially adjusted according to the sequence of the voltage phase angle of the representative node from small to large; the active output of the receiving-end power station is the sum of the active outputs of all power generation nodes in the receiving-end power station.
The verification unit 304 is configured to determine an updated tidal current value after power transmission section tidal current adjustment according to the adjusted active output of all the power stations; determining a tidal current deviation according to the target tidal current value and the updated tidal current value; and if the power flow deviation is larger than or equal to the preset threshold value, setting the updated power flow value as an initial power flow value, returning to the step of determining the power flow adjustment amount until the power flow deviation is smaller than the preset threshold value, and finishing the power flow adjustment of the power transmission section.
In one implementation, the preprocessing unit 301 is specifically configured to:
and dividing a preset power grid into two systems at the position of a power transmission section.
And according to the active power flow direction, a system which sends out power in the two systems is used as a sending end system, and a system which flows in power in the two systems is used as a receiving end system.
In one implementation, the power flow adjustment amount, the sending-end unit adjustment amount, and the receiving-end unit adjustment amount are determined by:
Figure BDA0002736913660000121
wherein, Δ P is the power flow adjustment amount, P1Is the target tidal current value, P0Is the initial tidal current value, Δ PmFor adjustment of sending-end unit, Δ PnAnd adjusting the quantity for the receiving end unit.
In an implementation manner, the first adjusting unit 303 is specifically configured to:
and sequencing all the transmitting-end power stations according to the sequence of the voltage phase angles of the representative nodes from large to small to obtain a transmitting-end power station sequence.
And aiming at a first sending end power station in the sending end power station sequence, determining an active regulating value of a first power generation node according to the adjustment quantity of a sending end unit, the active output of the first power generation node in the first sending end power station and the maximum active output of the first power generation node.
And if the active regulating value of the first power generation node is not equal to the adjustment value of the sending end unit, determining the active regulating value of the next power generation node according to a first difference value between the adjustment value of the sending end unit and the active regulating value of the first power generation node, the active output of the next power generation node in the first sending end power station and the maximum active output of the next power generation node.
And if the sum of the active adjustment values of all the power generation nodes in the first sending-end power station is not equal to the adjustment amount of the sending-end unit, continuously determining the active adjustment value of each power generation node in the second sending-end power station in the sending-end power station sequence until the sum of the adjusted active adjustment values of all the power generation nodes in the sending-end power station sequence is equal to the adjustment amount of the sending-end unit, and adjusting the active output of the corresponding power generation node according to the adjusted active adjustment value of each power generation node in the sending-end power station sequence.
In an implementation manner, the first adjusting unit 303 is specifically configured to:
sequencing all receiving-end power stations according to the sequence of voltage phase angles of the representative nodes from small to large to obtain a receiving-end power station sequence;
aiming at a first receiving-end power station in a receiving-end power station sequence, determining an active regulating value of a first receiving-end power generation node according to a receiving-end unit regulating quantity, the active output of the first receiving-end power generation node in the first receiving-end power station and the maximum active output of the first receiving-end power generation node;
if the active regulating value of the first receiving end generating node is not equal to the regulating value of the receiving end unit, determining the active regulating value of the next generating node according to the difference value of the regulating value of the receiving end unit and the active regulating value of the first receiving end generating node, the active output of the next generating node in the first receiving end power station and the maximum active output of the next generating node;
and if the sum of the active regulating values of all the generating nodes in the first receiving end power station is not equal to the adjusting amount of the receiving end unit, continuously determining the active regulating value of each generating node in the second receiving end power station in the receiving end power station sequence until the sum of the adjusted active regulating values of all the generating nodes in the receiving end power station sequence is equal to the adjusting amount of the receiving end unit, and adjusting the active output of the corresponding generating node according to the adjusted active regulating value of each generating node in the receiving end power station sequence.
In one implementation, the apparatus further comprises:
the second adjusting unit is used for sequentially adjusting the active output of each sending-end power station according to the adjustment quantity of the sending-end unit, the active output of each power generation node in the sending-end power station of the sending-end system and the maximum active output of each power generation node according to the sequence that the voltage phase angle of the representative node is from small to large if the tidal current adjustment quantity is smaller than zero; the active output of the sending-end power station is the sum of the active outputs of all power generation nodes in the sending-end power station;
according to the adjustment quantity of the receiving end unit, the active output of each power generation node in the receiving end power station of the receiving end system and the maximum active output of each power generation node, the active output of each receiving end power station is sequentially adjusted according to the sequence of voltage phase angles of the representative nodes from large to small; the active output of the receiving-end power station is the sum of the active outputs of all power generation nodes in the receiving-end power station.
Therefore, the influence of the power generation node on the stability of the power grid is reflected through the voltage phase angle of the power generation node in the power grid, the power generation node with the largest voltage phase angle in each power station is used as the representative node of the power station, the power stations are sequenced according to the voltage phase angle of each representative node, and the active output of each power station is sequentially regulated according to the sequence which is most unfavorable for the stability of the power grid, namely, the power flow is regulated. The tide adjusting method can ensure that the minimum, namely the most conservative section limit is obtained, and is more favorable for the safety and the stability of a power grid.
In an exemplary embodiment, a computer-readable storage medium is further provided, in which a computer program or an intelligent contract is stored, and the computer program or the intelligent contract is loaded and executed by a node to implement the transaction processing method provided by the above-described embodiment. Alternatively, the computer-readable storage medium may be a Read-Only Memory (ROM), a Random Access Memory (RAM), a CD-ROM, a magnetic tape, a floppy disk, an optical data storage device, and the like.
Those skilled in the art will clearly understand that the techniques in the embodiments of the present application may be implemented by way of software plus a required general hardware platform. Based on such understanding, the technical solutions in the embodiments of the present application may be essentially implemented or a part contributing to the prior art may be embodied in the form of a software product, which may be stored in a storage medium, such as a ROM/RAM, a magnetic disk, an optical disk, etc., and includes several instructions for enabling a computer device (which may be a personal computer, a server, or a network device, etc.) to execute the method described in the embodiments or some parts of the embodiments of the present application.
Other embodiments of the disclosure will be apparent to those skilled in the art from consideration of the specification and practice of the disclosure disclosed herein. This application is intended to cover any variations, uses, or adaptations of the disclosure following, in general, the principles of the disclosure and including such departures from the present disclosure as come within known or customary practice within the art to which the disclosure pertains. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the disclosure being indicated by the following claims.
It will be understood that the present disclosure is not limited to the precise arrangements described above and shown in the drawings and that various modifications and changes may be made without departing from the scope thereof. The scope of the present disclosure is limited only by the appended claims.

Claims (10)

1. A power system transmission section power flow adjusting method is characterized by comprising the following steps:
carrying out load flow calculation on the power transmission section of the load flow to be adjusted to obtain a load flow result of the power transmission section; the power flow result comprises a voltage phase angle of a power generation node, active power output of the power generation node and a power flow value of each branch in the power transmission section;
dividing a preset power grid into a sending end system and a receiving end system at the position of the power transmission section according to the active power flow direction; the power transmission section comprises a plurality of branches; the power grid comprises a plurality of power generation stations; the power plant comprises a plurality of power generation nodes;
determining an initial tidal current value of the power transmission section according to the tidal current values of all the branches;
determining a maximum voltage phase angle from the voltage phase angles of all power generation nodes in the power station, and taking the power generation node corresponding to the maximum voltage phase angle as a representative node of the power station;
determining a power flow adjustment amount according to a preset target power flow value and the initial power flow value, and determining a sending end unit adjustment amount of a sending end system and a receiving end unit adjustment amount of a receiving end system according to the power flow adjustment amount;
if the tidal current adjustment quantity is larger than zero, sequentially adjusting the active output of each sending end power station according to the adjustment quantity of the sending end unit, the active output of each power generation node in the sending end power station of the sending end system and the maximum active output of each power generation node in the sequence from large to small of the voltage phase angle of the representative node; the active output of the sending-end power station is the sum of the active outputs of all power generation nodes in the sending-end power station;
according to the receiving end unit adjustment quantity, the active output of each power generation node in the receiving end power station of the receiving end system and the maximum active output of each power generation node, sequentially adjusting the active output of each receiving end power station according to the sequence of the voltage phase angle of the representative node from small to large; the active output of the receiving-end power station is the sum of the active outputs of all power generation nodes in the receiving-end power station;
determining an updated tidal current value after the tidal current of the power transmission section is adjusted according to the adjusted active output of all the power stations;
determining a tidal current deviation according to the target tidal current value and the updated tidal current value;
and if the power flow deviation is greater than or equal to a preset threshold value, setting the updated power flow value as an initial power flow value, returning to the step of determining the power flow adjustment amount until the power flow deviation is less than the preset threshold value, and finishing the power flow adjustment of the power transmission section.
2. The method according to claim 1, wherein the dividing of the preset power grid into a sending-end system and a receiving-end system at the power transmission section according to an active power flow direction comprises:
dividing a preset power grid into two systems at the power transmission section;
and according to the active power flow direction, taking the system which sends out the power in the two systems as a sending end system, and taking the system which flows in the power in the two systems as a receiving end system.
3. The method of claim 1, wherein the power flow adjustment amount, the sending end unit adjustment amount, and the receiving end unit adjustment amount are determined by:
Figure FDA0002736913650000011
wherein Δ P is the power flow adjustment amount, P1In order to be the target tidal current value,P0is the initial tidal current value, Δ PmFor the adjustment of the sending end unit, Δ PnAnd adjusting the quantity of the receiving end unit.
4. The method of claim 1, wherein the adjusting the active power output of each transmitting end power station in turn is accomplished by:
sequencing all the transmitting-end power stations according to the sequence of the voltage phase angles of the representative nodes from large to small to obtain a transmitting-end power station sequence;
for a first sending-end power station in the sending-end power station sequence, determining an active regulating value of a first power generation node according to the sending-end unit regulating quantity, the active output of the first power generation node in the first sending-end power station and the maximum active output of the first power generation node;
if the active regulating value of the first power generation node is not equal to the adjustment value of the sending end unit, determining the active regulating value of the next power generation node according to a first difference value between the adjustment value of the sending end unit and the active regulating value of the first power generation node, the active output of the next power generation node in the first sending end power station and the maximum active output of the next power generation node;
if the sum of the active adjustment values of all the power generation nodes in the first sending-end power station is not equal to the sending-end unit adjustment amount, the active adjustment values of all the power generation nodes in the second sending-end power station in the sending-end power station sequence are continuously determined until the sum of the active adjustment values of all the power generation nodes adjusted in the sending-end power station sequence is equal to the sending-end unit adjustment amount, and the active output of the corresponding power generation node is adjusted according to the adjusted active adjustment values of all the power generation nodes in the sending-end power station sequence.
5. The method of claim 1, wherein the sequentially adjusting the active power output of each receiving end power station is accomplished by:
sequencing all receiving-end power stations according to the sequence of voltage phase angles of the representative nodes from small to large to obtain a receiving-end power station sequence;
for a first receiving-end power station in the receiving-end power station sequence, determining an active regulation value of a first receiving-end power generation node according to the receiving-end unit adjustment quantity, the active output of the first receiving-end power generation node in the first receiving-end power station and the maximum active output of the first receiving-end power generation node;
if the active regulating value of the first receiving end power generation node is not equal to the receiving end unit regulating value, determining the active regulating value of the next power generation node according to the difference value between the receiving end unit regulating value and the active regulating value of the first receiving end power generation node, the active output of the next power generation node in the first receiving end power station and the maximum active output of the next power generation node;
if the sum of the active adjustment values of all the power generation nodes in the first receiving-end power station is not equal to the receiving-end unit adjustment amount, the active adjustment values of all the power generation nodes in a second receiving-end power station in the receiving-end power station sequence are continuously determined until the sum of the active adjustment values of all the power generation nodes adjusted in the receiving-end power station sequence is equal to the receiving-end unit adjustment amount, and the active output of the corresponding power generation node is adjusted according to the adjusted active adjustment values of all the power generation nodes in the receiving-end power station sequence.
6. The method of claim 1, further comprising:
if the tidal current adjustment quantity is smaller than zero, sequentially adjusting the active output of each sending end power station according to the adjustment quantity of the sending end unit, the active output of each power generation node in the sending end power station of the sending end system and the maximum active output of each power generation node in the sequence from small voltage phase angle to large voltage phase angle of the representative node; the active output of the sending-end power station is the sum of the active outputs of all power generation nodes in the sending-end power station;
according to the receiving end unit adjustment quantity, the active output of each power generation node in the receiving end power station of the receiving end system and the maximum active output of each power generation node, the active output of each receiving end power station is sequentially adjusted according to the sequence of voltage phase angles of the representative nodes from large to small; the active output of the receiving-end power station is the sum of the active outputs of all power generation nodes in the receiving-end power station.
7. An apparatus for adjusting power flow in a power transmission section of a power system, the apparatus comprising:
the preprocessing unit is used for carrying out load flow calculation on the power transmission section of the load flow to be adjusted to obtain a load flow result of the power transmission section; the power flow result comprises a voltage phase angle of a power generation node, active power output of the power generation node and a power flow value of each branch in the power transmission section; dividing a preset power grid into a transmitting end system and a receiving end system according to the active power flow direction at the power transmission section; the power transmission section comprises a plurality of branches; the power grid comprises a plurality of power generation stations; the power plant comprises a plurality of power generation nodes; (ii) a Determining an initial tidal current value of the power transmission section according to the tidal current values of all the branches;
the processing unit is used for determining the maximum voltage phase angle from the voltage phase angles of all the power generation nodes in the power station and taking the power generation node corresponding to the maximum voltage phase angle as a representative node of the power station; determining a power flow adjustment amount according to a preset target power flow value and the initial power flow value, and determining a sending end unit adjustment amount of a sending end system and a receiving end unit adjustment amount of a receiving end system according to the power flow adjustment amount;
the first adjusting unit is used for sequentially adjusting the active output of each sending-end power station according to the adjustment quantity of the sending-end unit, the active output of each power generation node in the sending-end power station of the sending-end system and the maximum active output of each power generation node according to the sequence of the voltage phase angle of the representative node from large to small if the power flow adjustment quantity is larger than zero; the active output of the sending-end power station is the sum of the active outputs of all power generation nodes in the sending-end power station; according to the adjustment quantity of the receiving end unit, the active output of each power generation node in the receiving end power station of the receiving end system and the maximum active output of each power generation node, the active output of each receiving end power station is sequentially adjusted according to the sequence of the voltage phase angle of the representative node from small to large; the active output of the receiving-end power station is the sum of the active outputs of all power generation nodes in the receiving-end power station;
the verification unit is used for determining an updated tidal current value after the tidal current of the power transmission section is adjusted according to the adjusted active output of all the power stations; determining a tidal current deviation according to the target tidal current value and the updated tidal current value; and if the power flow deviation is larger than or equal to a preset threshold value, setting the updated power flow value as an initial power flow value, and returning to the step of determining the power flow adjustment amount until the power flow deviation is smaller than the preset threshold value, and finishing the power flow adjustment of the power transmission section.
8. The apparatus according to claim 7, wherein the preprocessing unit is specifically configured to:
dividing a preset power grid into two systems at the power transmission section;
and according to the active power flow direction, taking the system which sends out the power in the two systems as a sending end system, and taking the system which flows in the power in the two systems as a receiving end system.
9. The apparatus of claim 7, wherein the power flow adjustment amount, the sending end unit adjustment amount, and the receiving end unit adjustment amount are determined by:
Figure FDA0002736913650000031
wherein Δ P is the power flow adjustment amount, P1Is the target tidal current value, P0Is the initial tidal current value, Δ PmFor the adjustment of the sending end unit, Δ PnAnd adjusting the quantity of the receiving end unit.
10. The apparatus of claim 7, further comprising:
the second adjusting unit is used for sequentially adjusting the active output of each sending-end power station according to the adjustment quantity of the sending-end unit, the active output of each power generation node in the sending-end power station of the sending-end system and the maximum active output of each power generation node according to the sequence of the voltage phase angle of the representative node from small to large if the flow adjustment quantity is smaller than zero; the active output of the sending-end power station is the sum of the active outputs of all power generation nodes in the sending-end power station; according to the receiving end unit adjustment quantity, the active output of each power generation node in the receiving end power station of the receiving end system and the maximum active output of each power generation node, the active output of each receiving end power station is sequentially adjusted according to the sequence of voltage phase angles of the representative nodes from large to small; the active output of the receiving-end power station is the sum of the active outputs of all power generation nodes in the receiving-end power station.
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