CN113884942A - SCADA data-based grounding line selection alarm correctness checking method - Google Patents
SCADA data-based grounding line selection alarm correctness checking method Download PDFInfo
- Publication number
- CN113884942A CN113884942A CN202111201166.6A CN202111201166A CN113884942A CN 113884942 A CN113884942 A CN 113884942A CN 202111201166 A CN202111201166 A CN 202111201166A CN 113884942 A CN113884942 A CN 113884942A
- Authority
- CN
- China
- Prior art keywords
- bus
- grounding
- scada
- signal
- line selection
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 238000000034 method Methods 0.000 title claims abstract description 46
- 238000004364 calculation method Methods 0.000 claims description 37
- 238000009826 distribution Methods 0.000 claims description 6
- 238000004891 communication Methods 0.000 claims description 5
- 230000000737 periodic effect Effects 0.000 claims description 4
- 230000009471 action Effects 0.000 description 12
- 238000004088 simulation Methods 0.000 description 10
- 238000004458 analytical method Methods 0.000 description 8
- 230000011664 signaling Effects 0.000 description 8
- 230000008859 change Effects 0.000 description 7
- 238000012549 training Methods 0.000 description 7
- 238000012545 processing Methods 0.000 description 6
- 230000002159 abnormal effect Effects 0.000 description 4
- 238000010586 diagram Methods 0.000 description 4
- 238000012544 monitoring process Methods 0.000 description 4
- 230000007935 neutral effect Effects 0.000 description 3
- 230000008569 process Effects 0.000 description 3
- 238000011084 recovery Methods 0.000 description 3
- 238000012795 verification Methods 0.000 description 3
- 238000005520 cutting process Methods 0.000 description 2
- 238000003745 diagnosis Methods 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 238000005457 optimization Methods 0.000 description 2
- 230000003068 static effect Effects 0.000 description 2
- 238000007619 statistical method Methods 0.000 description 2
- 241001465754 Metazoa Species 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 238000011217 control strategy Methods 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000004146 energy storage Methods 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 230000001052 transient effect Effects 0.000 description 1
Images
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
- G01R31/50—Testing of electric apparatus, lines, cables or components for short-circuits, continuity, leakage current or incorrect line connections
- G01R31/52—Testing for short-circuits, leakage current or ground faults
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Supply And Distribution Of Alternating Current (AREA)
- Remote Monitoring And Control Of Power-Distribution Networks (AREA)
Abstract
The invention discloses a ground connection line selection alarm correctness checking method based on SCADA data, which comprises the following steps: the SCADA collects various data in real time; the SCADA searches whether a bus grounding signal exists or not, and if yes, the bus grounding signal is judged to be a first bus grounding signal sent by a low-current grounding line selection device of the transformer substation or a second bus grounding signal calculated by the SCADA; if the bus grounding signal is the first bus grounding signal, the SCADA retrieves the self grounding judgment condition within the first preset time when the first bus grounding signal is received, and compares whether the first bus grounding signal exists or not; and if the bus grounding signal is the second bus grounding signal, the SCADA retrieves various received data within second preset time when the second bus grounding signal is received, and compares whether the second bus grounding signal exists. The invention can verify the correctness of the grounding line selection signal of the low-current grounding line selection device at the station end of the existing power plant so as to improve the accuracy of the grounding line selection alarm of the device and simultaneously facilitate the improvement of the device.
Description
Technical Field
The invention relates to a ground connection line selection alarm correctness checking method based on SCADA data, and belongs to the technical field of power system ground faults.
Background
In actual operation, single-phase or three-phase ground faults often occur in buses and lines of an electric power system, and particularly, the ground faults of the buses and the lines occur more frequently under severe weather conditions such as rainy season, strong wind, hail and the like. In addition, low-current ground faults caused by small animals, tree faults and the like also occur frequently. Most of the existing low-current grounding line selection devices for the transformer substation can only be used for detecting single-phase grounding faults, and have the problems of device faults, false grounding alarms and the like. In addition, the conditions of sending and reporting leakage caused by the dead halt of the device, the dead halt of the program card and the like also occur occasionally.
Disclosure of Invention
Based on the above, the invention provides a method for checking correctness of ground connection line selection alarm based on SCADA data, which can verify correctness of ground connection line selection signals of a low-current ground connection line selection device at a station end of a current power plant so as to improve the accuracy of ground connection line selection alarm of the device, and can improve the device conveniently at the same time so as to overcome the defects of the prior art.
The technical scheme of the invention is as follows: a grounding line selection alarm correctness checking method based on SCADA data comprises the following steps:
the method comprises the steps that various data are collected in real time through an SCADA (supervisory control and data acquisition), the SCADA is distributed at an electric power dispatching end, the various data are data of a power plant station end, the SCADA is in communication connection with the power plant station end, and the power plant station end is provided with a transformer substation low-current grounding line selection device;
the SCADA searches whether a bus grounding signal exists or not, and if yes, the bus grounding signal is judged to be a first bus grounding signal sent by the small-current grounding line selection device of the transformer substation or a second bus grounding signal calculated by the SCADA;
if the bus grounding signal is the first bus grounding signal, the SCADA retrieves the self grounding judgment condition within the first preset time when the first bus grounding signal is received, compares whether the first bus grounding signal exists or not, and counts whether the small-current grounding line selection device of the transformer substation is correct or not according to the comparison condition;
and if the bus grounding signal is the second bus grounding signal, the SCADA retrieves the received various types of data within second preset time when the second bus grounding signal is received, compares whether the second bus grounding signal exists or not, and counts whether the small-current grounding line selection device of the transformer substation is correct or not according to the comparison condition.
Optionally, if the first bus grounding signal exists, it is determined that the first bus grounding signal is correct, and the SCADA counts that the number of times of correct pairs of the small-current grounding line selection device of the substation is i + 1; if the first bus grounding signal does not exist, the SCADA retrieves the self grounding judgment condition within a third preset time of receiving the first bus grounding signal, and compares whether the first bus grounding signal exists or not; at the moment, if the first bus grounding signal still does not exist, the first bus grounding signal is judged to be incorrect, and the SCADA counts the false alarm times of the small-current grounding line selection device of the transformer substation to be j + 1; and if the first bus grounding signal exists, judging that the first bus grounding signal is correct, judging that the first bus grounding signal has time delay and is not high in precision, and counting the down-extending time number k of the small-current grounding line selection device of the transformer substation to be k +1 by the SCADA.
Optionally, if the second bus grounding signal exists, it is determined that the second bus grounding signal is correct, and the SCADA counts that the correct number of times of the pairs of the small-current grounding line selection device of the substation is m + 1; if the second bus grounding signal does not exist, the SCADA retrieves the various types of received data within a fourth preset time when the second bus grounding signal is received, and compares whether the second bus grounding signal exists or not; at the moment, if the second bus grounding signal still does not exist, the fact that the small-current grounding line selection device of the transformer substation has no bus grounding signal is judged, and the SCADA counts the number of times of missing report of the small-current grounding line selection device of the transformer substation to be h + 1; and if the second bus grounding signal exists, judging that the bus grounding signal of the small-current grounding line selection device of the transformer substation is correct, judging that time delay exists and the precision is not high, and counting the time k of the upward time delay of the small-current grounding line selection device of the transformer substation to be k +1 by the SCADA.
Optionally, the second bus grounding signal is obtained by periodically calculating SCADA according to the various types of data, and the bus grounding calculation method includes a single-phase grounding start criterion, a bus open-phase grounding judgment method, and a grounding fault judgment method through a low-resistance grounding system.
Optionally, the single-phase ground connection starting criterion is that a bus zero-sequence voltage, a bus three-phase power grid, a bus ground connection alarm and a line ground connection alarm in a main network system are utilized, and a "wave recording locking" or "wave recording starting" signal in a distribution network system passes through a logical and/or a non-combination of scenes to serve as a single-phase ground connection starting criterion, in periodic calculation, a set number of times of calculation is started, if the calculation result is "true", the bus is judged to be grounded, and otherwise, the bus is judged to be not grounded.
Optionally, for a bus open-phase, the bus open-phase determination method includes:
if the voltage of the grounding phase bus is smaller than a first preset value and the voltages of the non-grounding phase buses are all larger than a second preset value, the bus is judged to be open-phase; or the absolute value of the difference between any two phases of the bus voltage is greater than a third preset value, the bus is judged to be open-phase; or when any one of the voltages of the bus is smaller than a fourth preset value and at least one phase of the voltages of the other two phases is larger than a fifth preset value, the bus is judged to be open-phase;
for bus grounding, the bus grounding determination method comprises the following steps:
if the voltage grounding phase of the bus is smaller than the sixth preset value and the voltage of the non-grounding phase is larger than the seventh preset value, the bus is judged to be grounded; or if any phase voltage of the bus voltage is larger than an eighth preset value, and the absolute value of the difference between the other two phase voltages is larger than a ninth preset value, the bus is judged to be grounded.
Optionally, the method for determining the ground fault of the low-resistance grounding system includes calculating real-time data according to the power flow, and analyzing current directions of lines on the same bus, where the current directions of the fault line are opposite to those of other non-fault lines, so as to determine the fault line.
Optionally, the various types of data include bus voltage, line current, and signals sent by a line protection device.
Optionally, the verification method is operated according to a predetermined period, and the times h of missing report, the times i of correct right-down report, the times j of false report, the times k of time delay for down report, the times m of correct right-up report and the times n of time delay for up report of the small-current grounding line selection device are counted.
The invention has the beneficial effects that: the invention collects and analyzes various data of the power plant station end in real time through SCADA, after judging whether a bus grounding signal is from a low-current grounding line selection device or the SCADA calculates, whether the grounding line selection of the low-current grounding line selection device of the current plant station end is correct or not can be accurately calculated, the year/month availability, the correct rate, the error event record statistical analysis and the like of the low-current grounding line selection device are further calculated, and the invention is a more efficient and convenient processing scheme or means for finding the problems of the low-current grounding line selection device in time and determining the positions needing to be improved.
Drawings
FIG. 1 is a flow chart of a method according to an embodiment of the present invention;
FIG. 2 is a functional block diagram according to an embodiment of the present invention;
FIG. 3 is a diagram illustrating an embodiment of the present invention.
Detailed Description
In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in detail below. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein, but rather should be construed as broadly as the present invention is capable of modification in various respects, all without departing from the spirit and scope of the present invention.
Referring to fig. 1 to fig. 3, a method for checking correctness of ground line selection alarm based on SCADA data in the present embodiment includes:
s1, collecting various data in real time by the SCADA, wherein the SCADA is distributed at the power dispatching end, the various data are data of the power plant station end, the SCADA is in communication connection with the power plant station end, and the power plant station end is provided with a small-current grounding line selection device of a transformer substation.
The SCADA (system) is arranged at the power dispatching end and comprises modules of SCADA data processing and monitoring, prepositive acquisition, network topology, load prediction, short-circuit current calculation, dispatcher load flow and state estimation and the like, wherein the SCADA data processing and monitoring is used as a main control module and is respectively and electrically connected with the modules of the prepositive acquisition, the network topology, the load prediction, the short-circuit current calculation, the dispatcher load flow and state estimation and the like, the prepositive acquisition module is in communication connection with a telemechanical module at the power plant end, and the supervisory control system can receive various data at the power plant end through the telemechanical module and transmit control information to the power plant end through the telemechanical module to be executed.
The following explains the above functional modules:
and (3) an SCADA system: data acquisition, data processing, data monitoring and data real-time monitoring control.
Pre-collection: the remote control system is mainly in communication connection with a telecontrol module at a plant station end and is used for acquiring various data and transmitting command information and the like.
Network topology: the connection relation of the electric islands formed by all the substations in the region and the connection relation of the electric islands formed inside each substation.
And (3) state estimation: and State Estimation (SE for short), wherein the State Estimation provides the optimal Estimation values of the voltage (amplitude and phase) and the power flow of each bus in the power grid according to real-time information provided by the SCADA. The state estimation is analyzed and calculated according to the SCADA real-time remote signaling and telemetry data to obtain a relatively accurate and complete operation mode, and all bus voltages and all loads can be calculated. And simultaneously, the SCADA remote signaling and remote measuring are verified, remote measuring points which are possibly abnormal are provided, and the calculation result and the measuring quality mark are returned to the SCADA. The calculation result of the state estimation can be used by other application software in a real-time mode, for example, dispatcher load flow can perform simulation operation calculation on the basis of the calculation result of the state estimation.
Dispatcher trend: dispatcher trending is one of the most basic applications of PAS. Through on-line load flow calculation, mode adjustment can be carried out at any time, and active power distribution is more reasonable. By using the estimated data to perform load flow calculation, a scheduling staff can arrange a theoretical basis for a future performing mode, and the method is more accurate, more reliable and more capable of truly reflecting the state of the power grid than offline calculation. In the switching operation and accident handling process, the dispatcher trend can play a good role in decision assistance. Dispatcher load flow is a comprehensive application and comprises several sub-applications, such as dispatcher load flow, short circuit calculation, static safety analysis and reactive power optimization. Each sub-application has its own independent picture and its own independent main picture. The relation and data flow among all modules are introduced in an offline analysis picture, firstly, offline analysis software (dispatcher power flow, static safety analysis, short circuit calculation and reactive power optimization) acquires a latest power grid model, and then acquires a historical section after acquiring the power grid model, wherein the section acquisition also has a plurality of modes, such as historical section acquisition, real-time section acquisition, historical integral point section acquisition and the like. After the power grid model and the section are obtained, the off-line analysis software can be used for calculating, and the calculated result can be displayed on different pictures.
And (3) load prediction: the function of load prediction is: and predicting the future load of the predicted measuring point defined by the user.
Short-circuit current calculation: the short-circuit current is calculated in order to correct an overcurrent generated when a short circuit is caused in a circuit due to a fault or a connection error. The current that flows in an electrical system when an abnormal connection (short circuit) occurs between a phase and a phase or between a phase and ground (or neutral line) during operation is called a short-circuit current. The basic types of short circuits occurring in three-phase systems are three-phase short circuits, two-phase short circuits, single-phase-to-ground short circuits and two-phase-to-ground short circuits. The three-phase short circuit is called as symmetrical short circuit because the three-phase loop is symmetrical when in short circuit; the other short circuits all make the three-phase circuit asymmetric, so the three-phase circuit is called asymmetric short circuit. In a grid with a neutral point directly grounded, a short-circuit fault to ground is the largest, and accounts for about 90% of all short-circuit faults. In an electric power network in which the neutral point is not directly grounded, the short-circuit fault is mainly a short circuit between various phases. When a short circuit occurs, the current in the short circuit loop is greatly increased due to the reduction of the impedance of the power supply loop of the power supply and the transient process during sudden short circuit, and may exceed the rated current of the loop by many times. The magnitude of the short-circuit current depends on the electrical distance between the short-circuit point and the power supply, for example, when a short circuit occurs at the generator end, the maximum instantaneous value of the short-circuit current flowing through the generator can reach 10-15 times of the rated current of the generator, and in a large-capacity power system, the short-circuit current can reach tens of thousands of amperes.
Training and simulating a dispatcher: the Dispatcher Training Simulator (DTS) can provide a comprehensive power system simulation tool for the Dispatcher to train, examine and perform anti-accident exercises so as to improve the professional level and the working skill of power grid dispatching and management personnel; besides, the system is also used as an analysis and research tool for power grid operation, support and decision-making personnel. The training function mainly comprises power grid dispatching operation control simulation training and EMS system application operation simulation training. The dispatcher training simulation system can simulate various running states of the power system, including a normal state, an emergency state, a fault state and an accident recovery process, so that a student can train normal operation, accident handling and system recovery in the same dispatching environment as an actual dispatching center, master various functional modules of an EMS, is familiar with various operations, and experiences the change condition of the system with high fidelity while observing the system state and implementing control measures.
Automatic reactive power control: the AVC program runs in a regional dispatching center, a transformer substation and a centralized control station, mainly controls the voltage and the reactive power of a regional power grid, the transformer substation and the centralized control station, the software contains an automatic control strategy, and simultaneously supports a user to control a 9-region diagram or a 17-region diagram and increase or decrease related locking conditions. And topology analysis is required to be carried out during each operation, so that the control is more reliable. The AVC program can run on multiple nodes, but typically runs on two hosts, one on duty on standby, commanded by the attendant, and the standby synchronizing the attendant information. When the duty machine fails, the standby machine is automatically upgraded to the duty node.
In the SCADA system, the voltages of all the pivot points are analyzed in real time through real-time load flow calculation data, the voltage change of all buses in the whole network is analyzed, and the buses with abnormal phase voltages and abnormal zero sequence voltages are identified. The method comprises the steps of utilizing network topology calculation to analyze grounding of a certain bus on the network in real time, possibly resulting in grounding of all 220kV buses connected with the bus in the whole network, and grounding of other 220kV transformer substation areas, 110kV transformer substation areas and 35kV transformer substation areas connected with the 220kV bus, sending out an emergency alarm according to possible area grounding events, locating a Siamese grounding bus or a grounding bus, executing remote control circuit breaker breaking, cutting off a grounding circuit in time, and performing wheel cutting if necessary. By utilizing state estimation, the voltage and current or P, Q change of a total station or even a whole network caused by the voltage change of a bus in a certain transformer substation and the load change of the total station or the whole network caused by the switching-on and switching-off of a circuit breaker in the process of eliminating the ground fault are estimated. The method comprises the steps of utilizing a dispatcher training simulation system (DTS) to conduct grounding simulation on fault points which are possibly grounded by buses/lines in the whole network, achieving whole-process simulation of bus/line grounding fault 'fault definition-fault occurrence-fault analysis-fault judgment-fault analysis processing-fault removal', and achieving line selection and route pulling or round-trip simulation after bus/line grounding fault in a simulation environment. By utilizing fault (after event) analysis methods of fault inversion (PDR) and SOE, the fault inversion (PDR) provides analog quantity changes before, when and within a period of time after a power system fault occurs. The SOE provides a hard contact signal or a soft contact signal of the substation, and includes signals of switch, switch deflection, line protection actions, and the like, such as "protection action", "reclosing action", "PT disconnection", "device call", "simultaneous action of switching relays", "switch tripping", "switch on", "control loop disconnection", "no energy storage of spring", and the like. According to the analysis method, the time point of tripping and closing of the circuit breaker and the time point of obvious change of the analog quantity are found through unifying the time scale, the sequence of actions, namely the change of the analog quantity at the key time node is analyzed, and the possible reasons of the occurrence of the fault event are analyzed.
The scada system acquires remote signaling and remote measuring of the transformer substation in real time and has a remote control function on a station switch. The remote signaling comprises a protected hard contact and a soft message, SOE of a switch and a remote signaling deflection signal, the remote signaling comprises a real-time section under the application of SCADA and PAS, and the remote signaling and remote signaling data provide a rich data source for real-time diagnosis of bus/line grounding. The real-time PAS and SCADA models provide a complete power grid model for real-time diagnosis of bus/line grounding and automatic recovery of grounding faults. The Scada system diagnoses the grounding of the bus/line in real time and has a remote control function on a station switch, so that a decision and execution of the decision are provided for judging the grounding fault and automatically processing and recovering.
The various data include bus voltage, line current, signals sent by line protection devices and low current grounding line selection devices. Specifically, the bus voltage comprises line voltages Uab, Ubc, Uca, phase voltages Ua, Ub, Uc, and a zero sequence voltage Uo; line voltages include, but are not limited to, Ua, Ub, Uc, Uab, Ubc, Uca, U, Uo, 3 Uo; line currents include, but are not limited to, Ia, Ib, Ic, Iab, Ibc, Ica, Io, 3 Io; the signals sent by the line protection device comprise signals of overcurrent first-stage action, overcurrent second-stage action, zero-sequence voltage action, protection action, primary/secondary reclosing action and the like; the signal sent by the low-current grounding line selection device comprises a bus grounding signal.
And S2, the SCADA searches whether a bus grounding signal exists, and if so, the bus grounding signal is judged to be a first bus grounding signal sent by the small-current grounding line selection device of the transformer substation or a second bus grounding signal calculated by the SCADA.
Specifically, the SCADA searches whether a bus grounding signal exists in real time or periodically, and judges whether the bus grounding signal is sent out by a low-current grounding line selection device of the transformer substation or is calculated by the SCADA so as to select a verification scheme.
The SCADA obtains the grounding condition of all buses in the whole power grid through periodic calculation according to various data, and the bus grounding calculation method comprises a single-phase grounding starting criterion, a bus open-phase grounding judgment method and a grounding fault judgment method through a small-resistance grounding system.
The single-phase grounding starting criterion is that bus zero sequence voltage, a bus three-phase power grid, bus grounding alarm and line grounding alarm in a main network system and wave recording locking or wave recording starting signals in a distribution network system pass through logical AND/OR/NOT combination of scenes to serve as the single-phase grounding starting criterion, in periodic calculation, the set number of times of calculation is started, if the calculation result is 'true', the bus is judged to be grounded, and otherwise, the bus is judged not to be grounded.
Specifically, the single-phase grounding starting criterion is the starting criterion which uses 10kV/35kV bus zero-sequence voltage (3U0), 10kV/35kV bus three-phase power grid (Ua/Ub/Uc), 10kV/35kV bus grounding alarm, 10kV/35kV line grounding alarm in a main network system and uses 'wave recording locking' or 'wave recording starting' signals in a distribution network system to pass through logic AND or non-combination of scenes as single-phase grounding. Example (c): condition 1: x1 represents the zero sequence voltage (3U0) of the main grid 10kV bus, condition 2: x2 represents the mains grid 10kV bus a-phase voltage, condition 3: x3 represents the mains grid 10kV bus B-phase voltage, condition 4: x4 represents the mains grid 10kV bus C-phase voltage, condition 5: x5 represents the main network 10kV bus grounding alarm action, condition 6: x6 represents the signal action of 'wave recording locking' or 'wave recording starting' in the distribution network system, and the 10kV single-phase grounding starting condition expression is as follows: x1>30| ((x2<4.8& & x3>7.0& & x4>7.0) | (x2>7.0& & x3<4.8& & x4>7.0) | (x2>7.0& & x3>7.0& & x4<4.8)) | | | x5| | | x6, and so on, the 35kV single-phase ground start condition expression is: x1>30| ((x2<16.0& & x3>24.5& & x4>24.5) | (x2>24.5& & x3<16.0& & x4>24.5) | (x2>24.5& & x3>24.5& & x4<16.0)) | x5| | x 6. Starting 3 times of calculation in the acquisition period, and judging that the bus is grounded if the expression calculation results of the 3 times are all true, namely the calculation result is 'true'; and if at least one expression calculation result is not established in the continuous 3 times of calculation, namely the calculation result is false, judging that the bus is not grounded.
For the bus open-phase, the bus open-phase judgment method comprises the following steps: if the voltage of the grounding phase bus is smaller than a first preset value and the voltages of the non-grounding phase buses are all larger than a second preset value, the bus is judged to be open-phase; or the absolute value of the difference between any two phases of the bus voltage is greater than a third preset value, the bus is judged to be open-phase; or when any voltage of the bus voltage is smaller than a fourth preset value and at least one phase of the other two phases of voltages is larger than a fifth preset value, the bus is judged to be open-phase.
In the following expression, x1 is a Ua real-time value, x2 is a Ub real-time value, and x3 is a Uc real-time value.
Example (c): calculating the bus open phase to be used as auxiliary calculation of bus grounding, wherein the specific method comprises the following steps:
10kV bus phase failure:
(x1<4.5& x2>5.3& x3>5.3) | (x2<4.5& x1>5.3& x3>5.3) | (x3<4.5& x1>5.3& x2>5.3) (i.e., when the 10kV grounded phase bus voltage is less than 4.5kV and the ungrounded phase bus voltages are all greater than 5.3kV, the 10kV bus phase failure is determined) or (abs (x1-x2) >0.5) | (abs (x2-x3) >0.5) | (abs (x1-x3) >0.5) (i.e., when the absolute value of the difference between any two phases of the 10kV bus voltage is greater than 0.5kV, the 10kV phase failure is determined) or (x1<4.5& (x 24 > 5.5 > 5.593 | (x 845) | 3.5) | (i.5) | (x 843) > 5) | (i.5 kV) if the absolute value of the bus voltage is greater than 0.5 kV) is greater than 0.5kV, the 10kV bus voltage is greater than 0.5kV (i.5 kV) and the voltage is greater than 3.5 kV 5kV (i.5 kV) or (i.5 kV) the 10kV bus voltage is determined) is greater than 3.5 kV (i.e., the 10kV 5kV 3.5 kV) greater than 3.5 kV bus voltage is greater than 3.5 kV 6kV (i.5 kV) or less than 7 kV).
And (3) phase failure of a 35kV bus:
(x1<15& (x2>19| | x3>19)) | (x2<15& (x1>19| | | x3>19)) | (x3<15& (x1>19| | | x2>19)) (i.e., when any one phase voltage of the 35kV bus voltage is less than 15kV, if at least one phase of the other two phase voltages is greater than 19kV, the 35kV bus is judged to be open-phase).
For bus grounding, the bus grounding judgment method comprises the following steps: if the voltage grounding phase of the bus is smaller than the sixth preset value and the voltage of the non-grounding phase is larger than the seventh preset value, the bus is judged to be grounded; or if any phase voltage of the bus voltage is larger than an eighth preset value, and the absolute value of the difference between the other two phase voltages is larger than a ninth preset value, the bus is judged to be grounded.
Example (c): calculating the grounding of the bus, and the specific method is as follows:
grounding a 10kV bus:
(x1>6.3& x2>6.3& x3<5.2) | (x1>6.3& x3>6.3& x2<5.2) | (x2>6.3& x3>6.3& x1<5.2) (i.e., when the 10kV bus voltage ground phase is less than 5.2kV and the ungrounded phase voltages are all greater than 6.3kV, the 10kV bus ground is determined), or ((x1>6.5) & abs (x2-x3) >0.6) | ((x2>6.5) & abs (x1-x3) >0.6) | ((x 3) & 6.5) & abs (x1-x2) >0.6) (i.e., when any one phase voltage of the 10kV bus voltage is greater than 6.5, if the absolute difference of the other phases of the two phases of the 10kV bus voltage is greater than 0.6kV, the absolute difference of the two phases of the 10kV bus voltage is determined).
Grounding a 35kV bus:
(x1>23& x2>23& x3<18) | (x1>23& x3>23& x2<18) | (x2>23& x3>23& x1<18) (i.e., 35kV bus voltage is less than 18kV for any one phase bus voltage and is greater than 23kV for both other phases bus voltage, the 35kV bus is judged to be grounded.), or x1>26| | x2>26| | | x3>26| | abs (x1-x2) >10.5| | | abs (x1-x3) >10.5| abs (x2-x3) >10.5 (i.e., when 35kV bus voltage for any one phase is greater than 26kV, or the absolute value of the difference between any two phases is greater than 10.5kV, the 35kV bus is judged to be grounded).
When grounding occurs through a low resistance grounding system, the fault line current direction (direction of Io) is opposite to the non-fault line current direction, i.e., positive-negative. Therefore, the method for judging the grounding fault of the low-resistance grounding system comprises the steps of calculating real-time data according to the load flow, analyzing the current direction of each line on the same bus, wherein the current direction of a fault line is opposite to that of other non-fault lines, and judging the fault line.
The three bus/line grounding calculation methods are simultaneously configured in the Scada system, and one or more combined calculation methods are selected during specific operation and are selectable through a human-computer interface.
S3, if the bus grounding signal is the first bus grounding signal, the SCADA retrieves the self grounding judgment condition within the first preset time when the first bus grounding signal is received, compares whether the first bus grounding signal exists, and counts whether the small current grounding line selection device of the transformer substation is correct or not according to the comparison condition.
Specifically, if the bus grounding signal is judged to be the first bus grounding signal sent by the small-current grounding line selection device of the transformer substation, the SCADA retrieves the self grounding judgment condition within the time range of +/-1 min of the time scale of receiving the first bus grounding signal, compares and judges whether the first bus grounding signal exists, if the first bus grounding signal exists, judges that the first bus grounding signal is correct, and counts the downward correct times of the small-current grounding line selection device of the transformer substation to be i + 1. If the first bus grounding signal is judged to be absent, the SCADA retrieves the self grounding judgment condition within the time range of +/-5 min of the time scale of receiving the first bus grounding signal, and compares and judges whether the first bus grounding signal is present or not; at the moment, if the first bus grounding signal still does not exist, the first bus grounding signal is judged to be incorrect, and the SCADA counts the false alarm times of the small-current grounding line selection device of the transformer substation to be j + 1; and if the first bus grounding signal exists, judging that the first bus grounding signal is correct, judging that the first bus grounding signal has time delay and is not high in precision, and counting the down-extending time number k of the small-current grounding line selection device of the transformer substation to be k +1 by the SCADA.
And S4, if the bus grounding signal is the second bus grounding signal, the SCADA retrieves the received various types of data within the second preset time when the second bus grounding signal is received, compares whether the second bus grounding signal exists, and counts whether the small-current grounding line selection device of the transformer substation is correct or not according to the comparison condition.
Specifically, if the bus grounding signal is calculated by the SCADA, the SCADA searches the received low-current grounding line selection device signal within the time range of +/-1 min of the time scale when the SCADA judges grounding, and compares whether the second bus grounding signal is received. And if the second bus grounding signal is received, judging that the second bus grounding signal is correct, and counting the correct times of the small-current grounding line selection device of the transformer substation to m +1 by the SCADA. If the second bus grounding signal is not received, searching the received small current grounding line selection device signal by the scada within the time range of +/-5 min of the time scale for judging grounding by the scada, and comparing whether the second bus grounding signal is received or not; if the second bus grounding signal is still not received, judging that the small-current grounding line selection device of the transformer substation has no bus grounding signal, and counting the number of times of missing report of the small-current grounding line selection device of the transformer substation by using the SCADA (supervisory control and data acquisition) as h + 1; and if the second bus grounding signal is received, judging that the bus grounding signal of the small-current grounding line selection device of the transformer substation is correct, judging that time delay exists and the precision is not high, and counting the time k of the upward time delay of the small-current grounding line selection device of the transformer substation to be k +1 by the SCADA.
Optionally, the verification method is operated according to a predetermined period, and the times h of missing report, the times i of correct right-down report, the times j of false report, the times k of time delay for down report, the times m of correct right-up report and the times n of time delay for up report of the small-current grounding line selection device are counted. Specifically, the above calculations are run periodically. Counting the times h of missing report, the times i of correct time for down report, the times j of false report, the times k of time for down report, the times m of correct time for up report and the times n of time delay for up report of the small-current grounding line selection device according to the year, month and day, and calculating the grounding judgment delay rate, the missing report rate, the false report rate, the error event record and the like of the small-current grounding line selection device of each transformer substation/each quarter and the like according to requirements.
The invention collects and analyzes various data of the power plant station end in real time through SCADA, after judging whether a bus grounding signal is from a low-current grounding line selection device or the SCADA calculates, whether the grounding line selection of the low-current grounding line selection device of the current plant station end is correct or not can be accurately calculated, the year/month availability, the correct rate, the error event record statistical analysis and the like of the low-current grounding line selection device are further calculated, and the invention is a more efficient and convenient processing scheme or means for finding the problems of the low-current grounding line selection device in time and determining the positions needing to be improved.
The above-mentioned embodiments only express several embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the present invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.
Claims (9)
1. A grounding line selection alarm correctness checking method based on SCADA data comprises the following steps:
the method comprises the steps that various data are collected in real time through an SCADA (supervisory control and data acquisition), the SCADA is distributed at an electric power dispatching end, the various data are data of a power plant station end, the SCADA is in communication connection with the power plant station end, and the power plant station end is provided with a transformer substation low-current grounding line selection device;
the SCADA searches whether a bus grounding signal exists or not, and if yes, the bus grounding signal is judged to be a first bus grounding signal sent by the small-current grounding line selection device of the transformer substation or a second bus grounding signal calculated by the SCADA;
if the bus grounding signal is the first bus grounding signal, the SCADA retrieves the self grounding judgment condition within the first preset time when the first bus grounding signal is received, compares whether the first bus grounding signal exists or not, and counts whether the small-current grounding line selection device of the transformer substation is correct or not according to the comparison condition;
and if the bus grounding signal is the second bus grounding signal, the SCADA retrieves the received various types of data within second preset time when the second bus grounding signal is received, compares whether the second bus grounding signal exists or not, and counts whether the small-current grounding line selection device of the transformer substation is correct or not according to the comparison condition.
2. The SCADA data-based ground route selection alarm correctness checking method of claim 1, wherein,
if the first bus grounding signal exists, judging that the first bus grounding signal is correct, and counting the downward correct times of the small-current grounding line selection device of the transformer substation to i +1 by using the SCADA;
if the first bus grounding signal does not exist, the SCADA retrieves the self grounding judgment condition within a third preset time of receiving the first bus grounding signal, and compares whether the first bus grounding signal exists or not;
at the moment, if the first bus grounding signal still does not exist, the first bus grounding signal is judged to be incorrect, and the SCADA counts the false alarm times of the small-current grounding line selection device of the transformer substation to be j + 1; and if the first bus grounding signal exists, judging that the first bus grounding signal is correct, judging that the first bus grounding signal has time delay and is not high in precision, and counting the down-extending time number k of the small-current grounding line selection device of the transformer substation to be k +1 by the SCADA.
3. The method for checking the correctness of the grounding line selection alarm based on SCADA data as claimed in claim 1,
if the second bus grounding signal exists, judging that the second bus grounding signal is correct, and carrying out statistics on the correct times of the small-current grounding line selection device of the transformer substation by using the SCADA to obtain m + 1;
if the second bus grounding signal does not exist, the SCADA retrieves the various types of received data within a fourth preset time when the second bus grounding signal is received, and compares whether the second bus grounding signal exists or not;
at the moment, if the second bus grounding signal still does not exist, the fact that the small-current grounding line selection device of the transformer substation has no bus grounding signal is judged, and the SCADA counts the number of times of missing report of the small-current grounding line selection device of the transformer substation to be h + 1; and if the second bus grounding signal exists, judging that the bus grounding signal of the small-current grounding line selection device of the transformer substation is correct, judging that time delay exists and the precision is not high, and counting the time k of the upward time delay of the small-current grounding line selection device of the transformer substation to be k +1 by the SCADA.
4. The method for checking the correctness of the SCADA data-based ground connection line selection alarm as recited in claim 1, wherein the second bus grounding signal is obtained by periodically calculating SCADA according to the various types of data, and the bus grounding calculation method comprises a single-phase grounding start criterion, a bus open-phase grounding judgment method and a grounding fault judgment method through a low-resistance grounding system.
5. The method for checking the correctness of the SCADA data-based ground connection line selection alarm according to claim 4, wherein the single-phase ground connection start criterion is that a bus zero sequence voltage in a main network system, a bus three-phase power grid, a bus ground connection alarm, a line ground connection alarm and a logic and/or a non-combination of a wave recording locking signal or a wave recording start signal in a distribution network system are used as the start criterion of the single-phase ground connection, in the periodic calculation, the set number of times of calculation is started, if the calculation results are all true, the bus is judged to be grounded, and otherwise, the bus is judged to be ungrounded.
6. The SCADA data-based ground connection line selection alarm correctness checking method according to claim 4, wherein for a bus open-phase, the bus open-phase determining method comprises the following steps:
if the voltage of the grounding phase bus is smaller than a first preset value and the voltages of the non-grounding phase buses are all larger than a second preset value, the bus is judged to be open-phase; or the absolute value of the difference between any two phases of the bus voltage is greater than a third preset value, the bus is judged to be open-phase; or when any one of the voltages of the bus is smaller than a fourth preset value and at least one phase of the voltages of the other two phases is larger than a fifth preset value, the bus is judged to be open-phase;
for bus grounding, the bus grounding determination method comprises the following steps:
if the voltage grounding phase of the bus is smaller than the sixth preset value and the voltage of the non-grounding phase is larger than the seventh preset value, the bus is judged to be grounded; or if any phase voltage of the bus voltage is larger than an eighth preset value, and the absolute value of the difference between the other two phase voltages is larger than a ninth preset value, the bus is judged to be grounded.
7. The SCADA data-based ground connection line selection alarm correctness checking method according to claim 4, wherein the method for judging the ground fault through the low-resistance grounding system comprises the steps of calculating real-time data according to power flow, analyzing the current direction of each line on the same bus, wherein the current direction of a fault line is opposite to that of other non-fault lines, and judging the fault line.
8. The SCADA data based ground wire selection alarm correctness checking method of claim 1, wherein the various types of data comprise bus voltage, line current and signals emitted by a line protection device.
9. The SCADA data-based ground wire selection alarm correctness checking method of claim 1, wherein the checking method is operated according to a predetermined period, and the times of missing reporting h, the times of correct lower pair i, the times of false reporting j, the times of time delay lower pair k, the times of correct upper pair m and the times of time delay upper pair n of the small-current ground wire selection device are counted.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111201166.6A CN113884942B (en) | 2021-10-15 | 2021-10-15 | SCADA data-based grounding line selection alarm correctness checking method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111201166.6A CN113884942B (en) | 2021-10-15 | 2021-10-15 | SCADA data-based grounding line selection alarm correctness checking method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN113884942A true CN113884942A (en) | 2022-01-04 |
| CN113884942B CN113884942B (en) | 2024-04-05 |
Family
ID=79002917
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202111201166.6A Active CN113884942B (en) | 2021-10-15 | 2021-10-15 | SCADA data-based grounding line selection alarm correctness checking method |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN113884942B (en) |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR19990034487A (en) * | 1997-10-30 | 1999-05-15 | 이종훈 | High-resistance ground fault control system with transmission line and its control method |
| CN102565619A (en) * | 2012-02-16 | 2012-07-11 | 华北电力大学（保定） | State diagnosis method for small-current ground fault line selection device |
| CN102611080A (en) * | 2012-03-16 | 2012-07-25 | 国电南瑞科技股份有限公司 | Main station type small current grounding control method |
| CN109031044A (en) * | 2018-08-09 | 2018-12-18 | 国网浙江省电力有限公司温州供电公司 | A kind of dispatching terminal substation low current single-phase earthing automatic route selection method |
| CN111257698A (en) * | 2020-03-24 | 2020-06-09 | 上海君世电气科技有限公司 | Low-current grounding power grid continuous line selection system based on impedance change detection |
| CN111366815A (en) * | 2020-04-24 | 2020-07-03 | 北京东土科技股份有限公司 | Low-current grounding line selection method, device and medium based on power distribution station server |
-
2021
- 2021-10-15 CN CN202111201166.6A patent/CN113884942B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR19990034487A (en) * | 1997-10-30 | 1999-05-15 | 이종훈 | High-resistance ground fault control system with transmission line and its control method |
| CN102565619A (en) * | 2012-02-16 | 2012-07-11 | 华北电力大学（保定） | State diagnosis method for small-current ground fault line selection device |
| CN102611080A (en) * | 2012-03-16 | 2012-07-25 | 国电南瑞科技股份有限公司 | Main station type small current grounding control method |
| CN109031044A (en) * | 2018-08-09 | 2018-12-18 | 国网浙江省电力有限公司温州供电公司 | A kind of dispatching terminal substation low current single-phase earthing automatic route selection method |
| CN111257698A (en) * | 2020-03-24 | 2020-06-09 | 上海君世电气科技有限公司 | Low-current grounding power grid continuous line selection system based on impedance change detection |
| CN111366815A (en) * | 2020-04-24 | 2020-07-03 | 北京东土科技股份有限公司 | Low-current grounding line selection method, device and medium based on power distribution station server |
Non-Patent Citations (3)
| Title |
|---|
| 何绍洋;叶楠;: "小电流接地系统单相接地故障选线方法的分析", 电工电气, no. 04 * |
| 刘英杰;: "小电流接地选线装置的现场应用", 炼油与化工, no. 06 * |
| 宫朝臣;赵旭堂;: "小电流接地系统接地信号判断与处理", 农村电工, no. 12 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN113884942B (en) | 2024-04-05 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN104198884B (en) | Differential principle based large-scale power grid intelligent trouble diagnosis method | |
| CN103607042B (en) | The distribution network failure processing method of long fault indicator for overhead lines towards outskirts of a town | |
| CN103023149A (en) | Intelligent power distribution terminal and intelligent power distribution system based on IEC61850 | |
| Hardiman et al. | An advanced tool for analyzing multiple cascading failures | |
| CN114114003A (en) | Circuit breaker operation detection system based on data monitoring | |
| O'Brien et al. | Catching falling conductors in midair—detecting and tripping broken distribution circuit conductors at protection speeds | |
| CN113433419B (en) | Intelligent alarm method and system based on polymorphic data cooperative processing | |
| CN113922326B (en) | Bus/line grounding line selection wheel cutting method based on SCADA data | |
| CN107561408B (en) | Method for improving accuracy rate of small current ground fault line selection | |
| Sarathkumar et al. | A technical review on self-healing control strategy for smart grid power systems | |
| CN108011358A (en) | A kind of power distribution network multinode intelligent fault diagnosis method based on Situation Awareness | |
| CN113341272A (en) | Transient quantity-based power distribution network single-phase earth fault section positioning system and method | |
| CN115037046A (en) | Power secondary equipment running state analysis and detection system | |
| Chaves et al. | Development of an Automated Distribution Grid With the Application of New Technologies | |
| CN111327474B (en) | Power system fault diagnosis method based on topology analysis | |
| CN113866677B (en) | SCADA data-based ground fault removal correctness checking method | |
| CN113884942B (en) | SCADA data-based grounding line selection alarm correctness checking method | |
| CN114441896B (en) | Distribution network automatic simulation platform and FTU detection method | |
| CN113437805B (en) | Station domain visual anti-misoperation early warning method based on secondary loop online monitoring | |
| CN116169778A (en) | Processing method and system based on power distribution network anomaly analysis | |
| CN108847656B (en) | Distribution network grounding line selection protection system based on self-adaptive dynamic contribution rate | |
| CN113162118A (en) | Offshore low-voltage crossing detection method for wind generating set | |
| CN113013871A (en) | Load transfer method for power distribution network equipment during fault and maintenance | |
| CN111426982A (en) | Single-phase earth fault positioning method for power distribution overhead cable hybrid line | |
| Arghandeh et al. | Synchronized measurements and their applications in distribution systems: An update |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |