Method for optimizing 220kV incoming line operation mode of substation

Abstract

The invention belongs to the technical field of power system operation optimization, and particularly relates to a substation 220kV incoming line operation mode optimization method, which comprises the following steps of: before loop closing, measuring voltages on two sides of a loop closing point, acquiring a voltage difference, comparing the voltage difference with a voltage difference threshold value, preliminarily judging whether a loop closing condition is met or not, and avoiding equipment damage; the stability coefficient of each acquisition unit of the two incoming lines is obtained, the overall stability condition of the line voltage and load power of each incoming line in the acquisition unit can be reflected, and the characterization value of the stability coefficient is obtained by establishing a two-dimensional coordinate system of the stability coefficient changing along with time; the method is advantaged in that whether the two incoming lines satisfy the loop closing condition can be accurately determined through further comparison with the preset stability coefficient characterization value according to the specific value of the total time length and the acquisition period, risks after loop closing are further reduced, normal operation of the 220kV incoming lines of the marine power substation is protected, and the operation mode is optimized.

Description

Technical Field

[0001] The invention belongs to the technical field of power system operation optimization, in particular to a method for optimizing the operation mode of a 220kV incoming line of a substation. Background Art

[0002] With the continuous growth of electricity demand and the increasing complexity of the power grid structure, the optimization of substation operation mode has become the key to improving the stability and quality of power supply. As an important part of the urban power grid, the optimization of the 220kV incoming line operation mode of Haili Substation is of great significance to improving the power supply capacity and reliability of the entire power grid.

[0003] The existing Haili substation has two 220kV incoming lines, with double busbars running separately. When the workshop is under maintenance, the two lines have load imbalance, one of which will be reversed, while the other line still needs to supply load from the network, and it is urgent to balance the load of the two lines. At present, the 220kV double incoming lines in Haili substation have been adjusted from separate operation to closed loop operation. The loads of the two incoming lines are basically balanced, eliminating the problem of reverse load of the lines. The protection switch plays a protective role in the circuit, and can quickly cut off the power supply when a circuit fault occurs to prevent the circuit from continuing to work, thereby avoiding electrical equipment from being damaged or causing fire due to overload, short circuit and other reasons; however, after closing the ring, if the load of each component in the ring network exceeds its rated capacity, it will cause the equipment to be overloaded, and in serious cases, the equipment may be damaged; during the closed loop operation, if the protection setting value is improperly set or the protection device has defects, it may cause the protection to malfunction and affect the normal operation of the system.

[0004] To this end, the present invention provides a method for optimizing the operation mode of a 220kV incoming line of a substation. Summary of the invention

[0005] In order to make up for the deficiencies of the prior art, at least one technical problem raised in the background technology is solved.

[0006] The technical solution adopted by the present invention to solve the technical problem is: the substation 220kV incoming line operation mode optimization method of the present invention comprises: S1, set a collection cycle, divide the collection cycle into several collection units, and obtain the real-time operation data of the closing points of the two incoming 220kV lines of Haili Substation within the collection cycle, where the operation data includes the voltage values ​​U1 and U2 on both sides of the closing point; S2, analyzing and processing the operation data to obtain a voltage difference UC on both sides of the closing point, and comparing the voltage difference UC with a voltage difference threshold (the voltage difference threshold is obtained by a person skilled in the art based on historical data): obtaining a closing signal, a non-closing signal or a signal to be analyzed; S3, based on the signal to be analyzed, obtain the load power value of each acquisition unit in the acquisition period of the two incoming lines, and obtain the voltage stability coefficient and the load power stability coefficient of the two incoming lines respectively through analysis; calculate the stability coefficient of each acquisition unit of the two incoming lines respectively according to the voltage stability coefficient and the load power stability coefficient; S4, establish a two-dimensional coordinate system for the change of stability coefficient over time, obtain stability coefficient curves of the two incoming lines, set a stability coefficient threshold, mark the stability coefficient threshold in the two-dimensional coordinate system, obtain a stability coefficient threshold straight line, obtain the total time length that the stability coefficient curves of the two incoming lines are simultaneously located above the stability coefficient threshold straight line, obtain the ratio of the total time length to the acquisition period, and obtain a stability coefficient characterization value; S5, comparing the stability coefficient characterization value with the preset stability coefficient characterization value, and converting the signal to be analyzed into a closed-loop signal or a non-closed-loop signal for output.

[0007] Preferably, in S2, the operation data is analyzed and processed to obtain the voltage difference on both sides of the closing point, specifically: The voltage values ​​on both sides of the loop closing point are calculated by difference, and the absolute value of the obtained difference is taken. The absolute values ​​of all voltage differences in the corresponding acquisition unit are summed and averaged to obtain the voltage difference UC.

[0008] Preferably, the voltage difference UC is compared with the voltage difference threshold, specifically: The voltage difference threshold comprises a first voltage difference threshold YU1 and a second voltage difference threshold YU2, wherein the first voltage difference threshold YU1 and the second voltage difference threshold YU2; When the voltage difference UC is less than or equal to the first voltage difference threshold YU1, it indicates that the voltage difference on both sides of the closing point is within the allowable range, and a closing signal is generated; If the first voltage difference threshold value YU1 is less than the voltage difference value UC and less than the second voltage difference threshold value YU2, it indicates that the voltages on both sides of the closing point need to be analyzed in one step to generate a signal to be analyzed; If the voltage difference UC≥the second voltage difference threshold value YU2, it indicates that the voltage difference on both sides of the closing point exceeds the limit, and a closing-unable signal is generated.

[0009] Preferably, the voltage stability coefficient is obtained in the following manner: All voltage differences obtained in the acquisition unit are calculated using the variance formula to obtain the voltage stability coefficient.

[0010] Preferably, the load power stability coefficient is obtained in the following manner: All load power values ​​obtained in the acquisition unit are calculated using the variance formula to obtain the load power stability coefficient.

[0011] Preferably, the stability coefficient of each acquisition unit of the two incoming lines is calculated based on the voltage stability coefficient and the load power stability coefficient, specifically: The voltage stability factor and load power stability factor are marked as DW and FW respectively, and the formula The stability coefficient WDX is obtained, where a1 and a2 are both preset proportional coefficients, and a1+a2=1.

[0012] Preferably, a two-dimensional coordinate system is established in which the stability coefficient changes with time, specifically: With the time of each acquisition unit in the acquisition cycle as the X-axis and the stability coefficient as the Y-axis, the stability coefficient of each acquisition unit of the two incoming lines is substituted into the two-dimensional coordinate system to obtain a two-dimensional coordinate system in which the stability coefficient changes with time.

[0013] Preferably, the stability coefficient characterization value is compared with a preset stability coefficient characterization value, specifically: If the stability coefficient characterization value is greater than or equal to the preset stability coefficient characterization value, the signal to be analyzed is converted into a closed-loop signal output; If the stability coefficient characterization value is less than the preset stability coefficient characterization value, the signal to be analyzed is converted into a non-loop-closable signal output.

[0014] The beneficial effects of the present invention are as follows: 1. The method for optimizing the operation mode of the 220kV incoming line of a substation described in the present invention measures the voltage on both sides of the closing point before closing the loop, obtains the voltage difference, compares it with the voltage difference threshold, and preliminarily determines whether the closing conditions are met to avoid equipment damage.

[0015] 2. The method for optimizing the operation mode of the 220kV incoming line of the substation described in the present invention can reflect the overall stability of the line voltage and load power of each incoming line in this acquisition unit by respectively obtaining the stability coefficient of each acquisition unit of the two incoming lines, and then obtain the stability coefficient characterization value by establishing a two-dimensional coordinate system in which the stability coefficient changes with time. The stability coefficient characterization value is the total time length that the stability coefficient curves of the two incoming lines are simultaneously located above the stability coefficient threshold straight line, that is, the stability coefficients of the two incoming lines at the same time are simultaneously greater than the stability coefficient threshold, which is obtained by the ratio of the total time length to the acquisition period. By further comparing with the preset stability coefficient characterization value, it is possible to more accurately judge whether the two incoming lines meet the closing conditions, further reduce the risk after closing, protect the normal operation of the 220kV incoming line of Haili substation, and optimize the operation mode. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The present invention will be further described below in conjunction with the accompanying drawings.

[0017] Figure 1It is a method flow chart of the method for optimizing the operation mode of the 220kV incoming line of a substation according to the present invention. DETAILED DESCRIPTION

[0018] In order to make the technical means, creative features, objectives and effects achieved by the present invention easy to understand, the present invention is further explained below in conjunction with specific implementation methods. Embodiment 1

[0019] like Figure 1 As shown, the method for optimizing the operation mode of the 220 kV incoming line of a substation according to an embodiment of the present invention includes: S1, set a collection cycle, divide the collection cycle into several collection units, and obtain the real-time operation data of the closing points of the two incoming 220kV lines of Haili Substation within the collection cycle, where the operation data includes the voltage values ​​U1 and U2 on both sides of the closing point; S2, analyzing and processing the operation data to obtain a voltage difference UC on both sides of the closing point, and comparing the voltage difference UC with a voltage difference threshold (the voltage difference threshold is obtained by a person skilled in the art based on historical data): obtaining a closing signal, a non-closing signal or a signal to be analyzed; S3, based on the signal to be analyzed, obtain the load power value of each acquisition unit in the acquisition period of the two incoming lines, and obtain the voltage stability coefficient and the load power stability coefficient of the two incoming lines respectively through analysis; calculate the stability coefficient of each acquisition unit of the two incoming lines respectively according to the voltage stability coefficient and the load power stability coefficient; S4, establish a two-dimensional coordinate system of stability coefficient variation over time, obtain stability coefficient curves of the two incoming lines, set a stability coefficient threshold (the stability coefficient threshold is set by those skilled in the art based on historical experience), mark the stability coefficient threshold in the two-dimensional coordinate system, obtain a stability coefficient threshold straight line, obtain the total time length that the stability coefficient curves of the two incoming lines are simultaneously located above the stability coefficient threshold straight line, obtain the ratio of the total time length to the acquisition period, and obtain a stability coefficient characterization value; S5, comparing the stability coefficient characterization value with a preset stability coefficient characterization value (the preset stability coefficient characterization value is set by a person skilled in the art based on historical experience), and converting the signal to be analyzed into a closed-loop signal or a non-closed-loop signal for output.

[0020] It should be noted that by obtaining the stability coefficient of each collection unit of the two incoming lines respectively, the overall stability of the line voltage and load power of each incoming line in this collection unit can be reflected, and then by establishing a two-dimensional coordinate system for the stability coefficient to change over time, the stability coefficient characterization value can be obtained. The stability coefficient characterization value is the total time length that the stability coefficient curves of the two incoming lines are simultaneously located above the stability coefficient threshold straight line, that is, the stability coefficients of the two incoming lines at the same time are simultaneously greater than the stability coefficient threshold, which is obtained by the ratio of the total time length to the collection period. By further comparing with the preset stability coefficient characterization value, it is possible to more accurately determine whether the two incoming lines meet the closing conditions, further reduce the risk after closing, protect the normal operation of the 220kV incoming line of Haili Substation, and optimize the operation mode. Embodiment 2

[0021] In a specific embodiment, the operation data is analyzed and processed in S2 to obtain the voltage difference between the two sides of the closing point, which is specifically: The voltage values ​​on both sides of the loop closing point are calculated by difference, and the absolute value of the obtained difference is taken. The absolute values ​​of all voltage differences in the corresponding acquisition unit are summed and averaged to obtain the voltage difference UC.

[0022] In a specific embodiment, the voltage difference value UC is compared with the voltage difference threshold value, specifically: The voltage difference threshold includes a first voltage difference threshold YU1 and a second voltage difference threshold YU2 (the first voltage difference threshold YU1 and the second voltage difference threshold YU2 are summarized by those skilled in the art based on historical data), wherein the first voltage difference threshold YU1 and the second voltage difference threshold YU2; When the voltage difference UC is less than or equal to the first voltage difference threshold YU1, it indicates that the voltage difference on both sides of the closing point is within the allowable range, and a closing signal is generated; If the first voltage difference threshold value YU1 is less than the voltage difference value UC and less than the second voltage difference threshold value YU2, it indicates that the voltages on both sides of the closing point need to be analyzed to generate a signal to be analyzed; If the voltage difference UC≥the second voltage difference threshold YU2, it indicates that the voltage difference on both sides of the loop closing point exceeds the limit, and a loop closing failure signal is generated.

[0023] It should be noted that when a closing signal is generated, the voltage difference UC≤the first voltage difference threshold YU1, indicating that the voltage difference on both sides of the closing point is within the allowable range, and no excessive circulating current will be generated after the closing, so the closing can be performed; when a signal to be analyzed is generated, the first voltage difference threshold YU1<voltage difference UC<second voltage difference threshold YU2. At this time, it is not 100% certain whether excessive circulating current will be generated after the closing, and further analysis and determination are required; and when a non-closing signal is generated, the voltage difference UC≥second voltage difference threshold YU2, indicating that the closing will definitely generate excessive circulating current, which may easily damage the equipment. Before closing the loop, the voltages on both sides of the closing point are measured to obtain the voltage difference, which is compared with the voltage difference threshold to preliminarily determine whether the closing conditions are met to avoid equipment damage.

[0024] In a specific embodiment, the voltage stability coefficient is obtained in the following manner: All voltage differences obtained in the acquisition unit are calculated using the variance formula to obtain the voltage stability coefficient.

[0025] In a specific embodiment, the load power stability coefficient is obtained in the following manner: All load power values ​​obtained in the acquisition unit are calculated using the variance formula to obtain the load power stability coefficient.

[0026] In a specific embodiment, the stability coefficient of each acquisition unit of the two incoming lines is calculated based on the voltage stability coefficient and the load power stability coefficient, which is specifically: The voltage stability factor and load power stability factor are marked as DW and FW respectively, and the formula The stability coefficient WDX is obtained, where a1 and a2 are both preset proportional coefficients, and a1+a2=1.

[0027] It should be noted that the stability coefficient of each acquisition unit of the two incoming lines can reflect the overall stability of the line voltage and load power in this acquisition unit. a1 and a2 represent the influence of the voltage stability coefficient and the load power stability coefficient on the incoming line stability coefficient. The specific values ​​are set by technical personnel in this field based on experience. The larger the stability coefficient, the smaller the change of the line voltage and load power acquisition unit within the time period, which is more conducive to the closed-loop operation of the two incoming lines.

[0028] In a specific embodiment, a two-dimensional coordinate system of stability coefficient changing with time is established, specifically: With the time of each acquisition unit in the acquisition cycle as the X-axis and the stability coefficient as the Y-axis, the stability coefficient of each acquisition unit of the two incoming lines is substituted into the two-dimensional coordinate system to obtain a two-dimensional coordinate system in which the stability coefficient changes with time.

[0029] In a specific embodiment, the stability coefficient characterization value is compared with a preset stability coefficient characterization value (the preset stability coefficient characterization value is set by a person skilled in the art based on historical experience), specifically: If the stability coefficient characterization value is greater than or equal to the preset stability coefficient characterization value, the signal to be analyzed is converted into a closed-loop signal output; If the stability coefficient characterization value is less than the preset stability coefficient characterization value, the signal to be analyzed is converted into a non-loop-closable signal output.

[0030] The above shows and describes the basic principles, main features and advantages of the present invention. It should be understood by those skilled in the art that the present invention is not limited to the above embodiments. The above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A method for optimizing the operation mode of 220kV incoming line in a substation, characterized by: include S1, set a collection cycle, divide the collection cycle into several collection units, and obtain the real-time operation data of the closing points of the two incoming 220kV lines of Haili Substation within the collection cycle, where the operation data includes the voltage values ​​U1 and U2 on both sides of the closing point; S2, analyzing and processing the operation data to obtain the voltage difference UC on both sides of the closing point, and comparing the voltage difference UC with the voltage difference threshold to obtain a closing signal, a non-closing signal or a signal to be analyzed; S3, based on the signal to be analyzed, obtain the load power value of each acquisition unit in the acquisition period of the two incoming lines, and obtain the voltage stability coefficient and the load power stability coefficient of the two incoming lines respectively through analysis; calculate the stability coefficient of each acquisition unit of the two incoming lines respectively according to the voltage stability coefficient and the load power stability coefficient; S4, establish a two-dimensional coordinate system for the change of stability coefficient over time, obtain stability coefficient curves of the two incoming lines, set a stability coefficient threshold, mark the stability coefficient threshold in the two-dimensional coordinate system, obtain a stability coefficient threshold straight line, obtain the total time length that the stability coefficient curves of the two incoming lines are simultaneously located above the stability coefficient threshold straight line, obtain the ratio of the total time length to the acquisition period, and obtain a stability coefficient characterization value; S5, comparing the stability coefficient characterization value with the preset stability coefficient characterization value, and converting the signal to be analyzed into a closed-loop signal or a non-closed-loop signal for output.

2. The method for optimizing the operation mode of the 220 kV incoming line of a substation according to claim 1, characterized in that: In S2, the operation data is analyzed and processed to obtain the voltage difference on both sides of the closing point, which is specifically: The voltage values ​​on both sides of the loop closing point are calculated by difference, and the absolute value of the obtained difference is taken. The absolute values ​​of all voltage differences in the corresponding acquisition unit are summed and averaged to obtain the voltage difference UC.

3. The method for optimizing the operation mode of the 220 kV incoming line of a substation according to claim 2 is characterized in that: The voltage difference UC is compared with the voltage difference threshold, specifically: The voltage difference threshold includes a first voltage difference threshold YU1 and a second voltage difference threshold YU2, (the first voltage difference threshold YU1 and the second voltage difference threshold YU2 are summarized by those skilled in the art based on historical data), wherein the first voltage difference threshold YU1 and the second voltage difference threshold YU2; When the voltage difference UC is less than or equal to the first voltage difference threshold YU1, it indicates that the voltage difference on both sides of the closing point is within the allowable range, and a closing signal is generated; If the first voltage difference threshold value YU1 is less than the voltage difference value UC and less than the second voltage difference threshold value YU2, it indicates that the voltages on both sides of the closing point need to be analyzed in one step to generate a signal to be analyzed; If the voltage difference UC≥the second voltage difference threshold value YU2, it indicates that the voltage difference on both sides of the closing point exceeds the limit, and a closing-unable signal is generated.

4. The method for optimizing the operation mode of the 220 kV incoming line of a substation according to claim 3 is characterized in that: The voltage stability coefficient is obtained as follows: All voltage differences obtained in the acquisition unit are calculated using the variance formula to obtain the voltage stability coefficient.

5. The method for optimizing the operation mode of the 220 kV incoming line of a substation according to claim 4 is characterized in that: The load power stability coefficient is obtained as follows: All load power values ​​obtained in the acquisition unit are calculated using the variance formula to obtain the load power stability coefficient.

6. The method for optimizing the operation mode of the 220 kV incoming line of a substation according to claim 5, characterized in that: The stability coefficient of each acquisition unit of the two incoming lines is calculated based on the voltage stability coefficient and the load power stability coefficient, which is: The voltage stability coefficient and the load power stability coefficient are marked as DW and FW respectively, and the stability coefficient WDX is obtained by the formula WDX=DW×a1+FW×a2, wherein a1 and a2 are both preset proportional coefficients, and a1+a2=1.

7. The method for optimizing the operation mode of the 220 kV incoming line of a substation according to claim 6 is characterized in that: Establish a two-dimensional coordinate system where the stability coefficient changes with time, specifically: With the time of each acquisition unit in the acquisition cycle as the X-axis and the stability coefficient as the Y-axis, the stability coefficient of each acquisition unit of the two incoming lines is substituted into the two-dimensional coordinate system to obtain a two-dimensional coordinate system in which the stability coefficient changes with time.

8. The method for optimizing the operation mode of the 220 kV incoming line of a substation according to claim 7 is characterized in that: The stability coefficient characterization value is compared with the preset stability coefficient characterization value, specifically: If the stability coefficient characterization value is greater than or equal to the preset stability coefficient characterization value, the signal to be analyzed is converted into a closed-loop signal output; If the stability coefficient characterization value is less than the preset stability coefficient characterization value, the signal to be analyzed is converted into a non-loop-closable signal output.

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