CN110071499B - Method and system for rapidly judging safety loop closing of power distribution network - Google Patents
Method and system for rapidly judging safety loop closing of power distribution network Download PDFInfo
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Abstract
The invention discloses a method and a system for rapidly judging the safety loop closing of a power distribution network, which can rapidly judge whether a loop can be closed or not. The method comprises the following steps: building a typical closed loop model of the power distribution network; acquiring real-time operation condition parameters of a typical closed-loop model of the power distribution network; calculating steady-state current in the closed-loop operation process according to real-time operation condition parameters of a typical closed-loop model of the power distribution network; constructing a safe loop closing condition of the line; obtaining the steady state current of the line before the loop closing operation in the typical loop closing model of the power distribution network, judging whether the steady state current of the line before the loop closing operation meets the safe loop closing condition of the line, and if so, performing the line operation and the loop operation.
Description
Technical Field
The disclosure relates to a method and a system for rapidly judging safety loop closing of a power distribution network.
Background
During line maintenance or load adjustment, in order to ensure the continuity of residential and industrial electricity, it is necessary to minimize the number of affected users, and therefore, the closed loop power switching (hot reversing) operation gradually replaces the conventional "cold reversing" method. For a loop closing power-transfer circuit, a loop closing condition is required to be met, the change of the power flow after loop closing is ensured not to exceed the limits in aspects of relay protection, equipment capacity and the like, and the sensitivity of circuit protection is considered. Meanwhile, the power regulating equipment cannot be connected with a fault area, so that dangerous conditions such as expansion of a fault range and the like caused by power regulation are prevented.
In the existing method, only a certain key point of the distribution network loop closing operation is qualitatively or quantitatively researched, parameters contained in a calculation formula cannot be directly inquired and obtained, and a distribution network regulator cannot be quickly and effectively guided to judge whether loop closing is available or not in actual operation.
Therefore, an effective technical scheme is not available for how to quickly and effectively judge whether the loop closing of the distribution network line can be realized.
Disclosure of Invention
In order to overcome the defects of the prior art, the present disclosure provides a method and a system for quickly determining a power distribution network safety loop closing, which can quickly determine whether a loop can be closed.
The technical scheme adopted by the disclosure is as follows:
a method for rapidly judging the safety loop closing of a power distribution network comprises the following steps:
building a typical closed loop model of the power distribution network;
acquiring real-time operation condition parameters of a typical closed-loop model of the power distribution network;
calculating steady-state current in the closed-loop operation process according to real-time operation condition parameters of a typical closed-loop model of the power distribution network;
constructing a safe loop closing condition of the line;
obtaining the steady state current of the line before the loop closing operation in the typical loop closing model of the power distribution network, judging whether the steady state current of the line before the loop closing operation meets the safe loop closing condition of the line, and if so, performing the line operation and the loop operation.
Further, the typical closed-loop model of the power distribution network comprises a first transformer located at the 110kV side, a second transformer located at the 110kV side, a first line located at the 10kV side and connected with the first transformer, and a second line located at the 10kV side and connected with the second transformer; and a communication switch is connected between the first line and the second line.
Further, the real-time operation condition parameters of the typical closed loop model of the power distribution network comprise maximum allowable current of a line, voltage on two sides of a tie switch, impedance of a first transformer and a second transformer on a 110kV side equivalent to impedance on a 10kV side, and impedance of a first line and a second line on the 10kV side.
Further, the method for calculating the steady-state current in the loop closing operation process comprises the following steps:
(1-1) calculating the difference value of the voltages at the two sides of the interconnection switch;
(1-2) calculating the sum of the impedance equivalence of a first transformer at the 110kV side to the impedance at the 10kV side, the impedance equivalence of a second transformer at the 110kV side to the impedance at the 10kV side, the impedance of a first line at the 10kV side and the impedance of a second line;
and (1-2) comparing the difference value obtained in the step (1-1) with the sum value obtained in the step (1-2), and multiplying by a complex operator to obtain the steady-state current in the loop closing operation process.
Further, the construction method of the line safety loop closing condition comprises the following steps:
establishing a relational expression of the sum of the steady-state current of the circuit before the loop closing operation and the steady-state current in the loop closing operation and the steady-state current of the circuit after the loop closing operation according to the steady-state current in the loop closing operation process, and establishing a relational expression of the sum of the steady-state current of the circuit before the loop closing operation and the product of the steady-state current and the impact coefficient in the loop closing operation process and the maximum effective value of the loop closing impact current according to the steady-state current and the impact coefficient in the loop closing operation process;
setting a line current protection setting value, and respectively establishing a relational expression of the line current protection setting value and the maximum effective values of the steady-state current and the loop closing impact current of the circuit after loop closing operation;
establishing a relational expression between the difference value between the maximum allowable current of the 10kV side line and the steady-state current in the loop closing operation process and the steady-state current of the line before the loop closing operation by utilizing the relational expression between the line current protection setting value and the maximum allowable current of the 10kV side line and the relational expression between the line current protection setting value and the steady-state current of the second line after the loop closing operation and the maximum effective value of the loop closing impact current;
and establishing a relational expression between the difference between the maximum allowable current of the 10kV side circuit and the steady-state current in the maximum loop closing operation process and the steady-state current of the circuit before loop closing operation according to the steady-state current in the loop closing operation process and the relational expression between the difference between the maximum allowable current of the 10kV side circuit and the steady-state current in the loop closing operation process and the steady-state current of the second circuit before loop closing operation, namely the circuit safety loop closing condition.
Further, the circuit safety loop closing conditions are as follows:
wherein the content of the first and second substances,
respectively, the voltage on both sides of the interconnection switch K, ZH1、ZH2The impedance of the A transformer and the B transformer on the 110kV side are equivalent to the impedance, Z on the 10kV side1、Z2Respectively 10kV side line L1And L2Impedance Z is Z1、Z2、ZH1、ZH2Of minimum effective value, ImaxThe maximum allowable current of a 10kV line; i is1The first line steady-state current before the loop closing operation; i is2Is the second line steady-state current before the loop closing operation.
The utility model provides a system for fast speed judgments distribution network safety closes ring, characterized by: executing on the processor or the memory, configured to execute the following instructions:
building a typical closed loop model of the power distribution network;
acquiring real-time operation condition parameters of a typical closed-loop model of the power distribution network;
calculating steady-state current in the closed-loop operation process according to real-time operation condition parameters of a typical closed-loop model of the power distribution network;
constructing a safe loop closing condition of the line;
obtaining the steady state current of the line before the loop closing operation in the typical loop closing model of the power distribution network, judging whether the steady state current of the line before the loop closing operation meets the safe loop closing condition of the line, and if so, performing the line operation and the loop operation.
A computer readable storage medium having stored therein a plurality of instructions adapted to be loaded by a processor of a terminal device and to execute the method for fast determining a power distribution network closed loop.
A terminal device comprising a processor and a computer readable storage medium, the processor being configured to implement instructions; the computer readable storage medium is used for storing a plurality of instructions, and the instructions are suitable for being loaded by a processor and executing the method for rapidly judging the safety loop closing of the power distribution network.
Through the technical scheme, the beneficial effects of the disclosure are that:
(1) the method comprises the steps of firstly constructing a typical closed-loop model of the power distribution network, obtaining real-time operation condition parameters of the typical closed-loop model by combining a dispatching SCADA system on the typical closed-loop model of the power distribution network, calculating steady-state current in the closed-loop process, deducing a safe closed-loop condition expression of the steady-state current of a circuit before closed-loop, and judging whether closed-loop can be performed or not according to the magnitude of the steady-state current before closed-loop;
(2) according to the method, for a specific line, when the real-time current of the line before loop closing is smaller than the maximum steady-state current of the line before loop closing, loop closing can be safely carried out, calculation or test is not needed in advance, the judgment basis is simplified, reference is provided for a dispatcher to quickly judge, and the method is simple, quick, safe and effective.
Drawings
The accompanying drawings, which are included to provide a further understanding of the disclosure, illustrate embodiments of the disclosure and together with the description serve to explain the disclosure and are not to limit the disclosure.
Fig. 1 is a flowchart illustrating a method for quickly determining a safe loop closing of a power distribution network according to an embodiment of the present invention;
fig. 2 is a structural diagram of a typical closed loop model of a second distribution network in the embodiment;
fig. 3 is a simplified diagram of a typical closed loop model of a second distribution network according to the present embodiment;
FIG. 4 is a schematic diagram of a simulation model of a typical closed-loop model of a distribution network;
FIG. 5 is a diagram of the line current waveforms before and after loop closing;
FIG. 6 is a graph of line current waveforms before and after threshold loop closing.
Detailed Description
It should be noted that the following detailed description is exemplary and is intended to provide further explanation of the disclosure. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs.
It is noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments according to the present disclosure. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, and it should be understood that when the terms "comprises" and/or "comprising" are used in this specification, they specify the presence of stated features, steps, operations, devices, components, and/or combinations thereof, unless the context clearly indicates otherwise.
Example one
The embodiment provides a method for quickly judging a power distribution network safety loop, and referring to fig. 1, the method includes the following steps:
s101, building a typical closed loop model of the distribution network.
Specifically, the typical closed-loop model of the power distribution network built in the step 101 includes a first transformer and a second transformer which are arranged at 110kV sides, and a first line and a second line which are arranged at 10kV sides, wherein the first line is connected with the first transformer, the second line is connected with the second transformer, and a connection switch is connected between the first line and the second line.
S102, obtaining real-time operation condition parameters of the typical closed-loop model of the power distribution network.
Specifically, in step 102, the real-time operating condition parameters of the typical closed-loop model of the power distribution network are obtained by scheduling the SCADA system, and include the maximum allowable current of the line, the voltage across the interconnection switch K, the impedance of the first transformer at the 110kV side is equivalent to the impedance at the 10kV side, the impedance of the second transformer is equivalent to the impedance at the 10kV side, the impedance of the first line and the impedance of the second line at the 10kV side, and the steady-state currents of the first line and the second line before the closed-loop operation.
S103, calculating the steady-state current in the loop closing operation process.
Specifically, in step S103, the steady-state current in the loop closing operation process is calculated, and the following scheme is adopted:
s103-1, calculating the difference value of the voltages at the two sides of the interconnection switch K;
s103-2, calculating the sum of the impedance of the first transformer at the 110kV side equivalent to the impedance at the 10kV side, the impedance of the second transformer at the 110kV side equivalent to the impedance at the 10kV side, the impedance of the first line at the 10kV side and the impedance of the second line;
s103-3, comparing the difference value obtained in the step S103-1 with the sum value obtained in the step S103-2, and multiplying by a complex operator to obtain the steady-state current in the loop closing operation process.
S104, establishing a safety loop closing condition of the first line and the second line.
Specifically, in the step 104, the safety loop closing condition of the first line is established, and the following scheme may be adopted for specific implementation:
s1041-1, establishing a relational expression of the sum of the steady-state current of the first line before the loop closing operation and the steady-state current in the loop closing operation and the steady-state current of the first line after the loop closing operation according to the steady-state current in the loop closing operation obtained in the step 103, and establishing a relational expression of the sum of the product of the steady-state current of the first line before the loop closing operation and the steady-state current and the impact coefficient in the loop closing operation and the maximum effective value of the loop closing impact current according to the steady-state current and the impact coefficient in the loop closing operation obtained in the step 103;
s1041-2, setting a first line current protection setting value, and respectively establishing a relational expression of the first line current protection setting value and the maximum effective values of the first line steady-state current and the loop closing impact current after loop closing operation;
s1041-3, establishing a relational expression between the difference value between the maximum allowable current of the 10kV side circuit and the steady-state current in the loop closing operation process and the steady-state current of the first circuit before loop closing by utilizing the relation between the first circuit current protection setting value and the maximum allowable current of the 10kV side circuit and the relational expression between the first circuit current protection setting value obtained in the step 1041-2 and the maximum effective values of the steady-state current and the loop closing impact current of the first circuit after the loop closing operation;
s1041-4, establishing a relational expression between the difference between the maximum allowable current of the 10kV side circuit and the steady-state current in the maximum loop closing operation process and the steady-state current of the first circuit before loop closing according to the steady-state current in the loop closing operation process and the relational expression between the difference between the maximum allowable current of the 10kV side circuit and the steady-state current in the loop closing operation process and the steady-state current of the first circuit before loop closing, and obtaining the first circuit safety loop closing condition.
Similarly, in the step 104, the safety loop closing condition of the second line is established, and the following scheme may be adopted for specific implementation:
s1042-1, establishing a relational expression of the sum of the steady-state current of the second line before the loop closing operation and the steady-state current in the loop closing operation and the steady-state current of the second line after the loop closing operation according to the steady-state current in the loop closing operation obtained in the step 103, and establishing a relational expression of the sum of the product of the steady-state current of the second line before the loop closing operation and the steady-state current and the impact coefficient in the loop closing operation and the maximum effective value of the loop closing impact current according to the steady-state current and the impact coefficient in the loop closing operation obtained in the step 103;
s1042-2, setting a second line current protection setting value, and respectively establishing a relational expression of the second line current protection setting value and the maximum effective values of the second line steady-state current and the loop closing impact current after the loop closing operation;
s1042-3, establishing a relational expression between the difference value between the maximum allowable current of the 10kV side line and the steady-state current in the loop closing operation process and the steady-state current of the second line before loop closing by using the relation between the second line current protection setting value and the maximum allowable current of the 10kV side line and the relational expression between the second line current protection setting value obtained in the step 1042-2 and the steady-state current and the maximum effective value of the loop closing impact current of the second line after the loop closing operation;
s1042-4, establishing a relation between the difference between the maximum allowable current of the 10kV side circuit and the steady-state current in the maximum loop closing operation process and the steady-state current of the second circuit before loop closing according to the steady-state current in the loop closing operation process and the relation between the difference between the maximum allowable current of the 10kV side circuit and the steady-state current in the loop closing operation process and the steady-state current of the second circuit before loop closing, namely the second circuit safety loop closing condition.
And S105, judging whether the steady-state current of the first line and the steady-state current of the second line meet corresponding line safety loop closing conditions before loop closing, and if so, performing loop closing operation.
Specifically, in step 105, whether a first line safety loop closing condition is met is judged according to the magnitude of the first line steady-state current before loop closing; judging whether the second line safety loop closing condition is met or not according to the magnitude of the second line steady-state current before loop closing; if the conditions are met, performing loop closing operation.
The method for rapidly judging the safe loop closing of the power distribution network, provided by the embodiment, includes the steps of firstly constructing a typical loop closing model of the power distribution network, obtaining real-time operation condition parameters of the typical loop closing model by combining with a dispatching SCADA system on the typical loop closing model of the power distribution network, calculating steady-state current in the loop closing process, deducing a safe loop closing condition expression of the steady-state current of a circuit before loop closing, and judging whether the loop can be closed according to the magnitude of the steady-state current before loop closing.
Example two
To enable those skilled in the art to better understand the present application, a more detailed embodiment is listed below, and this embodiment provides a method for quickly determining a power distribution network security loop, which includes the following steps:
s201, building a typical closed loop model of the distribution network.
FIG. 2 shows the structure of a typical closed-loop model of a power distribution network, in which 110kV sides are an A transformer and a B transformer of a first stationVoltage transformer, 10kV side line L1And L2Line L1And L2The on-site phase checking is carried out, the condition of loop closing is preliminarily met, and the connection is carried out through a communication switch K.
Under normal conditions, the interconnection switch K is opened; when the loop closing operation is needed, the interconnection switch K is switched on.
S202, obtaining real-time operation condition parameters of the power distribution network typical closed-loop model.
Specifically, in step 202, the real-time operating condition parameters of the typical closed-loop model of the power distribution network, including the maximum allowable current I of the line, are obtained by scheduling the SCADA systemmaxVoltage on both sides of interconnection switch K
And
the impedance of two transformers at the 110kV side is equivalent to the impedance Z at the 10kV sideH1And ZH210kV loop closing line impedance Z1And Z2。
S203, calculating the steady-state current I in the closed loop operation processc。
Fig. 3 shows a simplified diagram of a typical closed loop model of a power distribution network, and the balance nodes are regarded as 110kV buses in fig. 3, and three phases are symmetrical.
The loop closing current consists of a steady-state current before loop closing and a loop closing circulation current, and the magnitude of the loop closing current can be calculated according to the superposition theorem.
Specifically, in step 203, define
For connecting voltage on two sides of switch K in loop closing process
Induced steady state current, definition IcFor the corresponding effective value, according to the superposition theorem and the parameters shown in fig. 3, the following can be obtained:
in the formula (I), the compound is shown in the specification,
respectively, the voltage on both sides of the interconnection switch K, ZH1、ZH2The impedance of the A transformer and the B transformer on the 110kV side are equivalent to the impedance, Z on the 10kV side1、Z2Respectively 10kV side line L1And L2The impedance of (c).
Step 204, obtaining the line L before loop closing1And L2Steady state current I of1、I2Judging the line L before loop closing1And L2Steady state current I of1、I2And the maximum allowable current I of the linemaxAnd if the loop closing condition is met, performing loop closing operation.
Specifically, in step 204, before the loop is configured, the 10kV side line L is connected to the loop1And a line L2Steady state currents of
And the corresponding effective values are respectively I1、I2After loop closing operation, 10kV side line L1And a line L2A steady state current of
And the corresponding effective values are respectively I'1、I′2，I′tThe maximum effective value of the loop closing impact current is as follows:
I′t≤I1+kIc (3)
wherein k is an impact coefficient and is 1.62;
after the loop closing operation, 10kV sideLine L1The steady state current of (c); i'1Is composed of
A valid value of (a);
before the loop closing operation, a 10kV side line L1A steady state current; i is1Is composed of
A valid value of (a); i'tThe maximum effective value of the loop closing impact current;
for steady-state current in the loop closing process, IcIs the corresponding valid value.
Obtaining the maximum allowable current I of the 10kV line according to the step 102maxSetting the corresponding line current protection setting value as IsetIf so:
I′1≤I1+Ic≤Imax (4)
I′t≤I1+kIc≤Iset (5)
when the formulas (4) and (5) are simultaneously established, the steady-state current of the loop closing is within the self bearing range of the circuit, the relay protection misoperation cannot be caused in the transient process, and the safety of the loop closing can be ensured.
For three-section protection of current of distribution network line, setting value IsetSatisfies the following conditions:
Imax≤Iset (6)
solving the following equations (4), (5) and (6) to obtain:
I1≤Imax-Ic (7)
when formula (7) holds and is based on the obtained IcThe operator on duty can adjust the steady-state current I of the circuit before loop closing1And (5) directly judging whether the loop can be closed directly or not.
Setting the impedance Z to Z1、Z2、ZH1、ZH2The minimum effective value among the effective values is obtained by the equations (1) and (7) simultaneously1Safe loop closing conditions are as follows:
the same way can obtain the line L2Safe loop closing conditions are as follows:
in the formulae (8), (9), I for a specific substation and a specific distribution network linemax、
Z can be inquired and obtained in a dispatching SCADA system, so that for the typical closed-loop network, the steady-state current I of the line before the closed loop1、I2When the circuit safety loop closing conditions given by the formulas (8) and (9) are met, the loop closing operation can be carried out.
The method for rapidly judging the safe loop closing of the power distribution network, provided by the embodiment, includes the steps of firstly constructing a typical loop closing model of the power distribution network, obtaining real-time operation condition parameters of the typical loop closing model by combining with a dispatching SCADA system on the typical loop closing model of the power distribution network, calculating steady-state current in the loop closing process, deducing a safe loop closing condition expression of the steady-state current of a circuit before loop closing, and judging whether the loop can be closed according to the magnitude of the steady-state current before loop closing.
The embodiment also provides simulation of the method for rapidly judging the power distribution network security loop closing, and the simulation implementation process is as follows:
a typical regional loop closing network simulation model is built through a Matlab/Simulink module, and the line current before and after loop closing is simulated, wherein the model is shown in FIG. 4.
In the simulation process, the interconnection switch K is controlled to be closed when 0.06s is set, and the loop closing operation is performed, and the loop closing current waveform in the process is shown in fig. 5.
From FIG. 5, it can be seen thatThe duration of the loop closing current transient process is about 0.02s, and t is satisfiedT≤tsetⅡConditions; the steady-state current effective value of the circuit before loop closing is 141A, and is within the range of the circuit safety loop closing condition (not more than 337A) proposed by the embodiment; the maximum impact current in the loop closing process is 411A and is smaller than an instantaneous quick-break protection action setting value 4200A; the steady state current effective value of the circuit after loop closing is about 212A and is less than the maximum allowable current 600A of the circuit. In summary, this kind of condition can not trigger circuit relay protection malfunction, satisfies the safe condition of closing the ring, can close the ring.
As the load current of the circuit before loop closing is gradually increased, the loop closing impact current and the steady-state current after loop closing are also increased. Effective value of steady-state current I of circuit before loop closing2at-310A, the current waveforms of the circuit before and after loop closing are shown in figure 6. It can be obtained from the graph that the loop closing impact current is increased to 930A, the steady-state current effective value after loop closing is also increased to 590A, which is close to the maximum allowable current of the line, in this case, a certain potential safety hazard exists in loop closing, and one-step calculation or test is required to ensure that the change of the tidal current of each link after loop closing does not exceed the limit in the aspects of relay protection, power grid stability, equipment capacity and the like.
The embodiment also provides a system for quickly judging a power distribution network safety loop, which runs on a processor or a memory and is configured to execute the following instructions:
building a typical closed loop model of the power distribution network;
acquiring real-time operation condition parameters of a typical closed-loop model of the power distribution network;
calculating steady-state current in the closed-loop operation process according to real-time operation condition parameters of a typical closed-loop model of the power distribution network;
constructing a safe loop closing condition of the line;
obtaining the steady state current of the line before the loop closing operation in the typical loop closing model of the power distribution network, judging whether the steady state current of the line before the loop closing operation meets the safe loop closing condition of the line, and if so, performing the line operation and the loop operation.
The embodiment also provides a computer-readable storage medium, wherein a plurality of instructions are stored, and the instructions are suitable for being loaded by a processor of a terminal device and executing the method for rapidly judging the power distribution network safety loop closing.
The embodiment also provides a terminal device, which comprises a processor and a computer readable storage medium, wherein the processor is used for realizing the instructions; the computer readable storage medium is used for storing a plurality of instructions, and the instructions are suitable for being loaded by a processor and executing the method for rapidly judging the safety loop closing of the power distribution network.
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 processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing 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 processing 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 processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process 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.
The above description is only a preferred embodiment of the present application and is not intended to limit the present application, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, improvement and the like made within the spirit and principle of the present application shall be included in the protection scope of the present application.
Although the present disclosure has been described with reference to specific embodiments, it should be understood that the scope of the present disclosure is not limited thereto, and those skilled in the art will appreciate that various modifications and changes can be made without departing from the spirit and scope of the present disclosure.
Claims (7)
1. A method for rapidly judging the safety loop closing of a power distribution network is characterized by comprising the following steps:
building a typical closed loop model of the power distribution network;
acquiring real-time operation condition parameters of a typical closed-loop model of the power distribution network;
obtaining real-time operation working condition parameters of a typical closed loop model of the power distribution network by a dispatching SCADA system, wherein the real-time operation working condition parameters comprise the maximum allowable current of a line, the voltage on two sides of a tie switch K, the impedance of a first transformer on a 110kV side is equivalent to the impedance of a 10kV side, the impedance of a second transformer is equivalent to the impedance of the 10kV side, the impedance of a first line and the impedance of a second line on the 10kV side, and the steady-state current of the first line and the second line before closed loop operation;
calculating steady-state current in the closed-loop operation process according to real-time operation condition parameters of a typical closed-loop model of the power distribution network;
the method for calculating the steady-state current in the closed loop operation process comprises the following steps:
(1-1) calculating the difference value of the voltages at the two sides of the interconnection switch;
(1-2) calculating the sum of the impedance equivalence of a first transformer at the 110kV side to the impedance at the 10kV side, the impedance equivalence of a second transformer at the 110kV side to the impedance at the 10kV side, the impedance of a first line at the 10kV side and the impedance of a second line;
(1-3) comparing the difference value obtained in the step (1-1) with the sum value obtained in the step (1-2), and multiplying by a complex operator to obtain a steady-state current in the loop closing operation process;
constructing a safe loop closing condition of the line;
the circuit safety loop closing conditions are as follows:
wherein the content of the first and second substances,
respectively, the voltage on both sides of the interconnection switch K, ZH1、ZH2The impedance of the A transformer and the B transformer on the 110kV side are equivalent to the impedance, Z on the 10kV side1、Z2Respectively 10kV side line L1And L2Impedance Z is Z1、Z2、ZH1、ZH2Of minimum effective value, ImaxThe maximum allowable current of a 10kV line; i is1The first line steady-state current before the loop closing operation; i is2The steady-state current of the second line before the loop closing operation;
obtaining the steady state current of the line before the loop closing operation in the typical loop closing model of the power distribution network, judging whether the steady state current of the line before the loop closing operation meets the safe loop closing condition of the line, and if so, performing the line operation and the loop operation.
2. The method for rapidly judging the safety loop closing of the power distribution network according to claim 1, wherein the typical loop closing model of the power distribution network comprises a first transformer positioned on a 110kV side, a second transformer positioned on the 110kV side, a first line connected with the first transformer positioned on a 10kV side, and a second line connected with the second transformer positioned on the 10kV side; and a communication switch is connected between the first line and the second line.
3. The method for rapidly judging the safety loop closing of the power distribution network as claimed in claim 1, wherein the real-time operation condition parameters of the typical loop closing model of the power distribution network comprise maximum allowable line current, voltage across a tie switch, impedance of a first transformer and a second transformer on a 110kV side equivalent to impedance on a 10kV side, and impedance of a first line and a second line on a 10kV side.
4. The method for rapidly judging the safety loop closing of the power distribution network according to claim 1, wherein the construction method of the circuit safety loop closing condition comprises the following steps:
establishing a relational expression of the sum of the steady-state current of the circuit before the loop closing operation and the steady-state current in the loop closing operation and the steady-state current of the circuit after the loop closing operation according to the steady-state current in the loop closing operation process, and establishing a relational expression of the sum of the steady-state current of the circuit before the loop closing operation and the product of the steady-state current and the impact coefficient in the loop closing operation process and the maximum effective value of the loop closing impact current according to the steady-state current and the impact coefficient in the loop closing operation process;
setting a line current protection setting value, and respectively establishing a relational expression of the line current protection setting value and the maximum effective values of the steady-state current and the loop closing impact current of the circuit after loop closing operation;
establishing a relational expression between the difference value between the maximum allowable current of the 10kV side line and the steady-state current in the loop closing operation process and the steady-state current of the line before the loop closing operation by utilizing the relational expression between the line current protection setting value and the maximum allowable current of the 10kV side line and the relational expression between the line current protection setting value and the steady-state current of the second line after the loop closing operation and the maximum effective value of the loop closing impact current;
and establishing a relational expression between the difference between the maximum allowable current of the 10kV side circuit and the steady-state current in the maximum loop closing operation process and the steady-state current of the circuit before loop closing operation according to the steady-state current in the loop closing operation process and the relational expression between the difference between the maximum allowable current of the 10kV side circuit and the steady-state current in the loop closing operation process and the steady-state current of the second circuit before loop closing operation, namely the circuit safety loop closing condition.
5. The utility model provides a system for fast speed judgments distribution network safety closes ring, characterized by: executing on the processor or the memory, configured to execute the following instructions:
building a typical closed loop model of the power distribution network;
acquiring real-time operation condition parameters of a typical closed-loop model of the power distribution network;
obtaining real-time operation working condition parameters of a typical closed loop model of the power distribution network by a dispatching SCADA system, wherein the real-time operation working condition parameters comprise the maximum allowable current of a line, the voltage on two sides of a tie switch K, the impedance of a first transformer on a 110kV side is equivalent to the impedance of a 10kV side, the impedance of a second transformer is equivalent to the impedance of the 10kV side, the impedance of a first line and the impedance of a second line on the 10kV side, and the steady-state current of the first line and the second line before closed loop operation;
calculating steady-state current in the closed-loop operation process according to real-time operation condition parameters of a typical closed-loop model of the power distribution network;
the method for calculating the steady-state current in the closed loop operation process comprises the following steps:
(1-1) calculating the difference value of the voltages at the two sides of the interconnection switch;
(1-2) calculating the sum of the impedance equivalence of a first transformer at the 110kV side to the impedance at the 10kV side, the impedance equivalence of a second transformer at the 110kV side to the impedance at the 10kV side, the impedance of a first line at the 10kV side and the impedance of a second line;
(1-3) comparing the difference value obtained in the step (1-1) with the sum value obtained in the step (1-2), and multiplying by a complex operator to obtain a steady-state current in the loop closing operation process;
constructing a safe loop closing condition of the line;
the circuit safety loop closing conditions are as follows:
wherein the content of the first and second substances,
respectively, the voltage on both sides of the interconnection switch K, ZH1、ZH2The impedance of the A transformer and the B transformer on the 110kV side are equivalent to the impedance, Z on the 10kV side1、Z2Respectively 10kV side line L1And L2Impedance Z is Z1、Z2、ZH1、ZH2Of minimum effective value, ImaxThe maximum allowable current of a 10kV line; i is1The first line steady-state current before the loop closing operation; i is2The steady-state current of the second line before the loop closing operation;
obtaining the steady state current of the line before the loop closing operation in the typical loop closing model of the power distribution network, judging whether the steady state current of the line before the loop closing operation meets the safe loop closing condition of the line, and if so, performing the line operation and the loop operation.
6. A computer-readable storage medium having stored therein a plurality of instructions, characterized in that: the instructions are suitable for being loaded by a processor of a terminal device and executing the method for rapidly judging the safety loop closing of the power distribution network as set forth in any one of claims 1 to 4.
7. A terminal device comprising a processor and a computer readable storage medium, the processor being configured to implement instructions; a computer readable storage medium for storing a plurality of instructions characterized by: the instructions are suitable for being loaded by a processor and executing the method for rapidly judging the safety loop closing of the power distribution network as claimed in any one of claims 1 to 4.
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| JPH1056737A (en) * | 1996-08-07 | 1998-02-24 | Toshiba Corp | Distribution system operating equipment |
| CN101908763A (en) * | 2010-07-23 | 2010-12-08 | 广东电网公司中山供电局 | Method for controlling distribution network closed loop |
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| CN108711850A (en) * | 2018-06-05 | 2018-10-26 | 国网上海市电力公司 | The determination method of safe Loop Closing Operation is carried out to medium voltage distribution network |
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| JPH1056737A (en) * | 1996-08-07 | 1998-02-24 | Toshiba Corp | Distribution system operating equipment |
| CN101908763A (en) * | 2010-07-23 | 2010-12-08 | 广东电网公司中山供电局 | Method for controlling distribution network closed loop |
| CN107749635A (en) * | 2017-11-15 | 2018-03-02 | 江苏方天电力技术有限公司 | A kind of closed loop network running optimizatin method |
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