Analysis, early warning and problem diagnosis method for potential low voltage of distribution network area

Abstract

The invention relates to the technical field of power distribution network risk analysis early warning and operation and maintenance first-aid repair, and discloses a power distribution network area potential low voltage analysis early warning and problem diagnosis method comprising the following steps: S1, obtaining three-phase voltage data and three-phase current data monitored by a power distribution network area, when any phase voltage data in the three-phase voltage data is smaller than a set threshold value, skipping to S2; s2, judging whether the fluctuation of the phase voltage data is caused by a non-fault reason or not; s3, carrying out initial analysis on the fluctuated phase voltage data so as to calculate an early warning grade, and meanwhile, finding out a reason for causing low voltage by combining the phase voltage data with corresponding phase current data; s4, judging whether the analysis period is ended or not; s5, judging whether the condition that the three-phase voltage data is lower than the threshold value occurs again in an analysis period; and S6, judging whether the power distribution transformer area is a transformer area which has been pre-warned but not subjected to closed-loop treatment or not. The power supply service level can be effectively improved.

Description

Technical Field

[0001] The present invention relates to the technical field of risk analysis, early warning and operation and maintenance repair of distribution networks, and in particular to a method for analyzing, early warning and diagnosing problems of potential low voltage in distribution network substations. Background Art

[0002] The quality of the power supply voltage of the distribution network is the prerequisite for ensuring the normal power supply of users. The distribution network will cause power supply voltage fluctuations due to reasons such as adjustment of operation mode, power failure of upstream power supply, fault of distribution network line, and defect of distribution transformer, resulting in the power supply voltage quality not meeting the power supply requirements. Among them, the low voltage problem in the distribution network substation is one of the main reasons affecting the power supply of users. At present, the analysis and processing of low voltage in the distribution network substation is mainly based on the passive arrangement of operation and maintenance personnel for on-site verification and problem investigation when the power company finds that low voltage has occurred in the substation or the user complains by phone about the power supply voltage problem. Such situations have already affected the power consumption of users, and no early intervention and advance disposal have been achieved.

[0003] Therefore, at this stage, it is necessary to design a method for analyzing, warning and diagnosing potential low voltage in distribution network substations, to give early warning of the potential risk of low voltage in distribution network substations, and to diagnose and analyze the problems causing low voltage, to support on-site personnel in actively carrying out equipment operation and maintenance and problem handling, to ensure the qualified power supply voltage quality in distribution network substations, and thus to improve the power supply service level. Summary of the invention

[0004] The present invention provides a method for analyzing, warning and diagnosing potential low voltage in a distribution network substation, which is used to solve the problem of passively arranging operation and maintenance personnel to conduct on-site verification and problem investigation only when low voltage has occurred in the distribution network substation or users have complained by phone about power supply voltage quality problems. It can intervene and deal with the problem in advance to avoid the impact of low voltage in the distribution network substation on users' electricity consumption, thereby effectively improving the power supply service level.

[0005] The present invention is achieved through the following technical solutions:

[0006] A method for analyzing, warning and diagnosing potential low voltage in a distribution network area, comprising:

[0007] S1, obtaining the three-phase voltage data and three-phase current data monitored by the distribution station area, and when any phase voltage data of the three-phase voltage data is less than a set threshold, jumping to S2;

[0008] S2, determine whether the fluctuation of the phase voltage data is caused by non-fault reasons. If so, no warning is issued. Otherwise, a low voltage risk event is generated, and then jump to S3;

[0009] S3, performing a preliminary analysis on the fluctuating phase voltage data to calculate the warning level, and at the same time, combining the phase voltage data with the corresponding phase current data to find out the cause of the low voltage, and at the same time, adding the warning level, cause and fluctuation time of the phase voltage data to the low voltage risk event;

[0010] S4, judging whether the analysis cycle is over, if so, ending the analysis, otherwise, jumping to S5;

[0011] S5, judging whether the three-phase voltage data is lower than the threshold value again in one analysis cycle, if so, jumping to S6, otherwise, returning to S4;

[0012] S6. Determine whether the distribution station area is an area that has been warned but not closed-loop handled before. If so, jump to S3; otherwise, jump to S2.

[0013] As an optimization, the non-fault reasons include power outage of the upper power supply of the distribution station area and adjustment of the operation mode.

[0014] As an optimization, if any phase voltage data of the distribution station area is equal to 0 and any phase current data is equal to 0, the cause of the fluctuation of the phase voltage data is the power failure of the upper power supply. If the maximum value of any phase voltage data is equal to 0, If it is less than 220V, the cause of the fluctuation of the phase voltage data is the adjustment of the operating mode.

[0015] As an optimization, in S3, the fluctuating phase voltage data is initially analyzed, and the specific process of calculating the warning level is as follows:

[0016] S3.1. Determine the fluctuation level B and the fluctuation matrix according to the phase voltage data of the fluctuation Wherein, m represents the number of the distribution station area, and the specific expression of the fluctuation level B is:

[0017]

[0018] in, Represents the i-th phase voltage data of the m-th distribution station area;

[0019] The volatility matrix The specific formula is:

[0020]

[0021] And the fluctuation matrix The initial time is 0;

[0022] S3.2, obtain the corresponding warning level D according to the fluctuation matrix of the mth distribution station area m, the warning level D m The specific expression is:

[0023]

[0024] As an optimization, the phase voltage data is combined with the corresponding phase current data to find out the cause of the low voltage:

[0025] Compare and as well as and Size:

[0026] like and It is determined that the cause of the low voltage is a fault in the upper power supply equipment;

[0027] like It is determined that the cause of the low voltage is a short-term surge in the load in the distribution station area;

[0028] like and It is determined that the cause of the low voltage is the wiring of the metering and collection terminals;

[0029] like and It is determined that the cause of the low voltage is a fault on the low-voltage side of the distribution station area;

[0030] in, are the phase voltage data of the nth phase of the mth transformer area at time t and time t-1, are the phase current data of the nth phase of the mth transformer area at time t and time t-1, They are the phase voltage data difference threshold and the phase current ratio threshold, n∈[1,2,3], corresponding to phases A, B, and C.

[0031] As an optimization, the low voltage risk event includes a low voltage risk event occurrence time field, a warning field, and a voltage drop cause, wherein the low voltage risk event occurrence time field is used to record the fluctuation time of the phase voltage data, the warning field is used to record the number of times each warning level occurs within the analysis period, and the voltage drop cause is used to record the number of times the cause of the low voltage occurs.

[0032] The present invention also discloses a system for analyzing, warning and diagnosing potential low voltage in a distribution network area, which is used to implement the aforementioned method for analyzing, warning and diagnosing potential low voltage in a distribution network area, and includes:

[0033] The acquisition start module is used to obtain the three-phase voltage data monitored by the distribution station area, and start the first judgment module when any phase voltage data of the three-phase voltage data is less than a set threshold;

[0034] The first judgment module is used to judge whether the fluctuation of the phase voltage data is caused by non-fault reasons. If so, no warning is issued; otherwise, a low voltage risk event is generated, and then the initial analysis module is started;

[0035] The initial analysis module is used to perform initial analysis on the fluctuating phase voltage data, thereby calculating the warning level. At the same time, the phase voltage data is combined with the corresponding phase current data to find out the cause of the low voltage. At the same time, the warning level, cause and fluctuation time of the phase voltage data are newly recorded in the low voltage risk event;

[0036] A second judgment module is used to judge whether the analysis cycle is completed;

[0037] A third judgment module is used to judge whether the three-phase voltage data is lower than the threshold again within an analysis cycle;

[0038] The fourth judgment module is used to judge whether the distribution station area is a station area that has been warned before but not closed-loop handled.

[0039] The present invention also discloses an electronic device, comprising: a processor, a memory and a computer program; wherein the processor is connected to the memory, the computer program is stored in the memory, and when the electronic device is running, the processor executes the computer program stored in the memory, so that the electronic device executes and implements a method for analyzing, warning and diagnosing problems of potential low voltage in a distribution network area as described above.

[0040] The present invention also discloses a storage medium, which is used to store computer instructions. When the computer instructions are executed by a processor, a method for analyzing, warning and diagnosing potential low voltage in a distribution network area as described above is implemented.

[0041] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0042] By monitoring the phase voltage and phase current of the distribution network substation, the present invention can intervene and take preemptive measures before low voltage occurs in the distribution network substation, thereby avoiding the situation where the operation and maintenance personnel are passively arranged to conduct on-site verification and problem investigation after low voltage occurs in the distribution network substation or when users complain by phone about power supply voltage quality problems, thereby avoiding the impact of low voltage in the distribution network substation on user electricity consumption, thereby effectively improving the power supply service level. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] The drawings described herein are used to provide a further understanding of the embodiments of the present invention, constitute a part of this application, and do not constitute a limitation of the embodiments of the present invention. In the drawings:

[0044] Figure 1 The present invention provides a flow chart of a method for analyzing, warning and diagnosing potential low voltage in a distribution network area. DETAILED DESCRIPTION

[0045] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with embodiments and drawings. The exemplary embodiments of the present invention and their description are only used to explain the present invention and are not intended to limit the present invention.

[0046] This embodiment 1 provides a method for analyzing, warning and diagnosing potential low voltage in a distribution network area. Figure 1 As shown, including:

[0047] S1. Obtain three-phase voltage data and three-phase current data monitored by the distribution station area, and jump to S2 when any phase voltage data of the three-phase voltage data is less than a set threshold; in some embodiments, the threshold is 220V.

[0048] That is, 1) according to the voltage data monitored by the distribution network area sensing equipment, potential low voltage analysis and early warning are carried out. When any phase of the three-phase voltage is less than 220V, the potential low voltage analysis and early warning are activated.

[0049] S2, determine whether the fluctuation of the phase voltage data is caused by non-fault reasons. If so, no warning is issued. Otherwise, a low voltage risk event is generated, and then jump to S3;

[0050] In some embodiments, the non-fault reasons include power outage of the upper power supply of the distribution station area and adjustment of the operation mode.

[0051] More specifically, if any phase voltage data of the distribution station area is equal to 0 and any phase current data is equal to 0, the cause of the fluctuation of the phase voltage data is the power failure of the upper power supply. If it is less than 220V, the cause of the fluctuation of the phase voltage data is the operating mode.

[0052] That is, 2) perform a preliminary analysis according to formula (1) to eliminate voltage fluctuations caused by power outages of the upper power supply, adjustments to the operating mode, etc.

[0053]

[0054] S3, performing a preliminary analysis on the fluctuating phase voltage data to calculate the warning level, and at the same time, combining the phase voltage data with the corresponding phase current data to find out the cause of the low voltage, and at the same time, adding the warning level, cause and fluctuation time of the phase voltage data to the low voltage risk event;

[0055] Specifically, the specific process of performing a preliminary analysis on the fluctuating phase voltage data and calculating the warning level is as follows:

[0056] S3.1. Determine the fluctuation level B and the fluctuation matrix according to the phase voltage data of the fluctuation Wherein, m represents the number of the distribution station area, and the specific expression of the fluctuation level B is:

[0057]

[0058] in, Represents the i-th phase voltage data of the m-th distribution station area;

[0059] The volatility matrix The specific formula is:

[0060]

[0061] And the fluctuation matrix The initial time is 0;

[0062] That is, 3) according to the initial analysis of step 2), when the value of A is 3, further analysis and processing is performed according to formula (2) and formula (3) to obtain the volatility matrix.

[0063] S3.2, obtain the corresponding warning level D according to the fluctuation matrix of the mth distribution station area m , the warning level D m The specific expression is:

[0064]

[0065] That is, 4) according to the matrix C obtained in step 3), the potential low voltage warning level D is obtained according to formula (4).

[0066] here, It refers to the sum of the occurrence of fluctuation matrices of all levels.

[0067] The phase voltage data is combined with the corresponding phase current data to find out the cause of the low voltage. In some embodiments, the phase voltage data is combined with the corresponding phase current data to find out the cause of the low voltage specifically as follows:

[0068] Compare and as well as and Size:

[0069] like and It is determined that the cause of the low voltage is a fault in the upper power supply equipment;

[0070] like It is determined that the cause of the low voltage is a short-term surge in the load in the distribution station area;

[0071] like and It is determined that the cause of the low voltage is the wiring of the metering and collection terminals;

[0072] like and It is determined that the cause of the low voltage is a fault on the low-voltage side of the distribution station area;

[0073] in, are the phase voltage data of the nth phase of the mth transformer area at time t and time t-1, are the phase current data of the nth phase of the mth transformer area at time t and time t-1, They are the phase voltage data difference threshold and the phase current ratio threshold, n∈[1,2,3], corresponding to phases A, B, and C.

[0074] That is, 5) according to the warning level obtained in step 4, if Dm is not equal to 0, the problem causing the voltage drop is analyzed according to formula (5).

[0075]

[0076] After obtaining the warning level, voltage drop cause and voltage drop time, these data must be recorded in the low voltage risk event. In some embodiments, the low voltage risk event includes a low voltage risk event occurrence time field, a warning field and a voltage drop cause. The low voltage risk event occurrence time field is used to record the fluctuation time of the phase voltage data, the warning field is used to record the number of times each warning level occurs within the analysis period, and the voltage drop cause is used to record the number of times each cause of low voltage occurs.

[0077] Each time S3 is executed, a record will be made in the low voltage risk event, and the record will be accumulated until the end of the analysis cycle.

[0078] S4, judging whether the analysis cycle is over, if so, ending the analysis, otherwise, jumping to S5;

[0079] S5, judging whether the three-phase voltage data is lower than the threshold value again in one analysis cycle, if so, jumping to S6, otherwise, returning to S4;

[0080] Here, we are analyzing the same substation. Therefore, in the same substation, no matter which phase has a problem, the voltage fluctuation of the previous phase will be recorded continuously.

[0081] S6. Determine whether the distribution station area is an area that has been warned but not closed-loop handled before. If so, jump to S3; otherwise, jump to S2.

[0082] That is, 6) within an analysis cycle X, when the three-phase voltage is lower than 220V again, determine whether the substation is a substation that has been warned but not closed-loop handled before. If not, jump to step 2); if so, jump to step 7).

[0083] 7) The time when the low voltage 220V occurs again is recorded in the generated low voltage risk event occurrence time field. At the same time, the warning level is obtained according to the voltage value according to step 4), and the number of occurrences is increased by 1 in the corresponding warning field in the event.

[0084] 8) Determine the number of times of the three warning level fields. When a higher warning level appears, update the low voltage warning level and jump to step 5) to analyze the cause of the voltage drop.

[0085] 9) After an analysis cycle X, the potential low voltage warning and problem diagnosis analysis of the m substation area is completed.

[0086] Next, the method of the present invention is described using specific data.

[0087]

[0088]

[0089]

[0090] The above table shows the voltage and current data of 96 collection points in the T-stage area in one day. At 12:30, the B-phase voltage was lower than 200V, and the potential low voltage analysis warning was initiated.

[0091] According to step 2, a preliminary analysis is performed. The three-phase voltages are not 0, and the currents are not 0 either. Voltage fluctuations caused by power outages of the upper power supply, adjustment of the operating mode, etc. can be ruled out. The value of A is 3 according to formula (1).

[0092] Continue to step 3 and determine that the value of A is equal to 3. According to formula (2), Then B = 3, and according to formula (3) we get

[0093] Continue to step 4 and obtain D according to formula (4). T =3.

[0094] Continue to step 5 and calculate and Get the data in the following table.

[0095]

[0096]

[0097] According to formula (5), according to the historical operation of the T-stage area, set The possible cause of low voltage is poor wiring of the metering acquisition terminal.

[0098] Continue to execute steps 6, 7, and 8. At 12:45, the voltage of phase B is lower than 200V, and the T area is the area that has been warned before but not closed-loop handled, and the voltage is less than 198V. The number of low-voltage level 3 warnings increases by 1.

[0099] Until step 9, at 23:45, the analysis was completed and the T-stage area had a third-level low-voltage warning, with a cumulative number of 46 times. It was suspected that the problem was caused by poor wiring of the metering and collection terminals. The potential low-voltage warning and problem diagnosis analysis was completed.

[0100] Embodiment 2 further discloses a system for analyzing, warning and diagnosing potential low voltage in a distribution network area, which is used to implement a method for analyzing, warning and diagnosing potential low voltage in a distribution network area of ​​embodiment 1, including:

[0101] The acquisition start module is used to obtain the three-phase voltage data monitored by the distribution station area, and start the first judgment module when any phase voltage data of the three-phase voltage data is less than a set threshold;

[0102] The first judgment module is used to judge whether the fluctuation of the phase voltage data is caused by non-fault reasons. If so, no warning is issued; otherwise, a low voltage risk event is generated, and then the initial analysis module is started;

[0103] The initial analysis module is used to perform initial analysis on the fluctuating phase voltage data, thereby calculating the warning level. At the same time, the phase voltage data is combined with the corresponding phase current data to find out the cause of the low voltage. At the same time, the warning level, cause and fluctuation time of the phase voltage data are newly recorded in the low voltage risk event;

[0104] A second judgment module is used to judge whether the analysis cycle is completed;

[0105] A third judgment module is used to judge whether the three-phase voltage data is lower than the threshold again within an analysis cycle;

[0106] The fourth judgment module is used to judge whether the distribution station area is a station area that has been warned before but not closed-loop handled.

[0107] Example 3 also discloses an electronic device, comprising: a processor, a memory and a computer program; wherein the processor is connected to the memory, the computer program is stored in the memory, and when the electronic device is running, the processor executes the computer program stored in the memory, so that the electronic device executes a method for analyzing, warning and diagnosing potential low voltage in a distribution network area as in Example 1.

[0108] Embodiment 4 further discloses a storage medium, which is used to store computer instructions. When the computer instructions are executed by a processor, a method for analyzing, warning and diagnosing potential low voltage in a distribution network area as described in Embodiment 1 is implemented.

[0109] The specific implementation methods described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific implementation method of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for analyzing, warning and diagnosing potential low voltage in a distribution network area, characterized in that: include: S1, obtaining the three-phase voltage data and three-phase current data monitored by the distribution station area, and when any phase voltage data of the three-phase voltage data is less than a set threshold, jumping to S2; S2, determine whether the fluctuation of the phase voltage data is caused by non-fault reasons. If so, no warning is issued. Otherwise, a low voltage risk event is generated, and then jump to S3; S3, performing a preliminary analysis on the fluctuating phase voltage data to calculate the warning level, and at the same time, combining the phase voltage data with the corresponding phase current data to find out the cause of the low voltage, and at the same time, adding the warning level, cause and fluctuation time of the phase voltage data to the low voltage risk event; S4, judging whether the analysis cycle is over, if so, ending the analysis, otherwise, jumping to S5; S5, judging whether the three-phase voltage data is lower than the threshold value again in one analysis cycle, if so, jumping to S6, otherwise, returning to S4; S6. Determine whether the distribution station area is an area that has been warned but not closed-loop handled before. If so, jump to S3; otherwise, jump to S2.

2. A method for analyzing, warning and diagnosing potential low voltage in a distribution network area according to claim 1, characterized in that: The threshold value is 220V.

3. The method for analyzing, warning and diagnosing potential low voltage in a distribution network area according to claim 1 is characterized in that: The non-fault reasons include power outage of the upper power supply of the distribution station area and adjustment of the operation mode.

4. The method for analyzing, warning and diagnosing potential low voltage in a distribution network area according to claim 1 is characterized in that: If any phase voltage data of the distribution station area is equal to 0 and any phase current data is equal to 0, the cause of the fluctuation of the phase voltage data is the power failure of the upper power supply. If it is less than 220V, the cause of the fluctuation of the phase voltage data is the adjustment of the operating mode.

5. The method for analyzing, warning and diagnosing potential low voltage in a distribution network area according to claim 1 is characterized in that: In S3, the fluctuating phase voltage data is initially analyzed to calculate the warning level in the following specific process: S3.

1. Determine the fluctuation level B and the fluctuation matrix according to the phase voltage data of the fluctuation Wherein, m represents the number of the distribution station area, and the specific expression of the fluctuation level B is: in, Represents the i-th phase voltage data of the m-th distribution station area; The volatility matrix The specific formula is: And the fluctuation matrix The initial time is 0; S3.2, obtain the corresponding warning level D according to the fluctuation matrix of the mth distribution station area m , the warning level D m The specific expression is:

6. The method for analyzing, warning and diagnosing potential low voltage in a distribution network area according to claim 1 is characterized in that: The phase voltage data is combined with the corresponding phase current data to find out the cause of low voltage: Compare and as well as and Size: like and It is determined that the cause of the low voltage is a fault in the upper power supply equipment; like It is determined that the cause of the low voltage is a short-term surge in the load in the distribution station area; like and It is determined that the cause of the low voltage is the wiring of the metering and collection terminals; like and It is determined that the cause of the low voltage is a fault on the low-voltage side of the distribution station area; in, are the phase voltage data of the nth phase of the mth transformer area at time t and time t-1, are the phase current data of the nth phase of the mth transformer area at time t and time t-1, They are the phase voltage data difference threshold and the phase current ratio threshold, n∈[1,2,3], corresponding to phases A, B, and C.

7. The method for analyzing, warning and diagnosing potential low voltage in a distribution network area according to claim 1, characterized in that: The low voltage risk event includes a low voltage risk event occurrence time field, a warning field, and a voltage drop cause, wherein the low voltage risk event occurrence time field is used to record the fluctuation time of the phase voltage data, the warning field is used to record the number of times each warning level occurs within the analysis period, and the voltage drop cause is used to record the number of times the cause of the low voltage occurs.

8. A potential low voltage analysis, early warning and problem diagnosis system for distribution network areas, characterized in that: A method for analyzing, warning and diagnosing potential low voltage in a distribution network area according to any one of claims 1 to 7, comprising: The acquisition start module is used to obtain the three-phase voltage data monitored by the distribution station area, and start the first judgment module when any phase voltage data of the three-phase voltage data is less than a set threshold; The first judgment module is used to judge whether the fluctuation of the phase voltage data is caused by non-fault reasons. If so, no warning is issued; otherwise, a low voltage risk event is generated, and then the initial analysis module is started; The initial analysis module is used to perform initial analysis on the fluctuating phase voltage data, thereby calculating the warning level. At the same time, the phase voltage data is combined with the corresponding phase current data to find out the cause of the low voltage. At the same time, the warning level, cause and fluctuation time of the phase voltage data are newly recorded in the low voltage risk event; A second judgment module is used to judge whether the analysis cycle is completed; A third judgment module is used to judge whether the three-phase voltage data is lower than the threshold again within an analysis cycle; The fourth judgment module is used to judge whether the distribution station area is a station area that has been warned before but not closed-loop handled.

9. An electronic device, characterized in that: include: A processor, a memory and a computer program; wherein the processor is connected to the memory, the computer program is stored in the memory, and when the electronic device is running, the processor executes the computer program stored in the memory so that the electronic device executes a method for analyzing, warning and diagnosing potential low voltage in a distribution network substation as described in any one of claims 1 to 7.

10. A storage medium, characterized in that: The storage medium is used to store computer instructions. When the computer instructions are executed by the processor, a method for analyzing, warning and diagnosing potential low voltage in a distribution network area is implemented as described in any one of claims 1 to 7.

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