Patent Publication Number: US-2022236727-A1

Title: Monitoring control apparatus

Description:
TECHNICAL FIELD 
     The present disclosure relates to a monitoring control apparatus. 
     BACKGROUND ART 
     A conventional monitoring control system in an electric power system widely adopts the function of, in the event of any abnormality in a monitoring target device, displaying an alarm message on a human machine interface (HMI) screen to notify a system operator with the occurring abnormality. 
     As a technique of issuing an alarm, for example, WO 2013/047651 (PTL 1) discloses a technique of determining a parent-child relationship between alarms and grouping alarms having the parent-child relationship, and causing a touch panel display to display the alarms having the parent-child relationship. 
     CITATION LIST 
     Patent Literature 
     
         
         PTL 1: WO 2013/047651 
       
    
     SUMMARY OF INVENTION 
     Technical Problem 
     In PTL 1, the alarm issued based on the alarm from the interlock management unit is defined as “parent alarm”, and the alarm issued based on the alarm from the module controller is defined as “child alarm”, and the alarms are associated with each other. It is disclosed that, as the method for association, a list of alarm names is stored in advance in the interlock management unit and the module controllers depending on the type of interlock factor. 
     In PTL 1, however, the parent alarm and the child alarm are merely associated with each other in advance. Thus, in the event where multiple abnormalities have occurred in a monitoring target device, a degree of association of an abnormality with any other abnormality cannot be appropriately notified to a system operator at the moment of the occurrence. 
     An object in an aspect of the present disclosure is to provide a monitoring control apparatus that can more appropriately notify the association among a plurality of abnormalities of a monitoring target device provided in an electric power system. 
     Solution to Problem 
     A monitoring control apparatus according to an embodiment includes: a display controller to display an alarm screen for notifying a plurality of abnormalities occurring in a monitoring target device provided in an electric power system; a selector to select a first abnormality among the plurality of abnormalities; a degree-of-association calculator to calculate, for each of one or more other abnormalities except for the first abnormality among the plurality of abnormalities, a degree of association of the other abnormality with the first abnormality; and an extractor to extract the other abnormality as an associated abnormality associated with the first abnormality when the degree of association of the other abnormality is not less than a threshold. The alarm screen includes an associated alarm for notification of the extracted associated abnormality. 
     Advantageous Effects of Invention 
     According to the present disclosure, the association among a plurality of abnormalities of a monitoring target device provided in an electric power system can be notified more appropriately. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  shows an example system configuration including a monitoring control apparatus. 
         FIG. 2  is a block diagram showing an example hardware configuration of the monitoring control apparatus. 
         FIG. 3  shows an example alarm screen. 
         FIG. 4  shows an example display screen of a schematic diagram. 
         FIG. 5  is a diagram for illustrating another example display of the alarm screen. 
         FIG. 6  is a diagram for illustrating still another example display of the alarm screen. 
         FIG. 7  is a block diagram showing a functional configuration of the monitoring control apparatus. 
         FIG. 8  shows an example procedure of the monitoring control apparatus. 
         FIG. 9  shows an example alarm screen according to another embodiment. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     Embodiments will now be described with reference to the drawings. The same or corresponding parts in the drawings have the same reference characters allotted. Their names and functions are also the same. Thus, detailed description thereof will not be repeated. 
     &lt;System Configuration&gt; 
       FIG. 1  shows an example system configuration including a monitoring control apparatus  100 . Referring to  FIG. 1 , monitoring control apparatus  100  is used for monitoring and control of a relatively large-scale apparatus or facility, such as control of an electric power system. Monitoring control apparatus  100  typically receives signals indicating various statuses of a monitoring target device (also simply referred to as “target device” below) and detects an abnormality of the monitoring target device based on the received signal. 
     Specifically, monitoring control apparatus  100  monitors and controls various target devices  2 A,  2 B, . . .  2 N (also collectively referred to as “target device  2 ” below) provided in an electric power system. Examples of target device  2  include transformer station equipment such as a gas circuit breaker (GCB), a transformer, a current transformer, a potential transformer, a disconnecting switch, an earthing switch, and a lightning arrester provided in an electric power system including an electric power station, a transformer station and the like. Target device  2  has a communications function for communications with monitoring control apparatus  100 . 
     Monitoring control apparatus  100  is configured so as to communicate with target device  2  via a network  4 . Monitoring control apparatus  100  collects various pieces of information from target device  2  and stores the various pieces of information in an internal memory or the like. Network  4  is, for example, a wide-area internet protocol (IP) network laid over a wide area. 
     Monitoring control apparatus  100  generates various screens for monitoring and control of target device  2  and displays the generated various screens on a display. Specifically, monitoring control apparatus  100  displays an alarm screen for notifying the nature of an abnormality of target device  2  which is detected based on signals from various detection circuits (e.g., sensors) provided in target device  2 . This allows a user (e.g., system operator) operating monitoring control apparatus  100  can check the presence or absence of an abnormality of target device  2 . The system operator performs operation input to monitoring control apparatus  100  using a keyboard, a mouse or the like while checking the alarm screen. The manner of displaying the alarm screen in monitoring control apparatus  100  will be described below in detail. 
     &lt;Hardware Configuration&gt; 
       FIG. 2  is a block diagram showing an example hardware configuration of monitoring control apparatus  100 . Referring to  FIG. 2 , monitoring control apparatus  100  includes a processor  150 , a main storage device  152 , a secondary storage device  154 , a communication interface (I/F)  156 , a display  158 , an input device  160 , a speaker  162 , and a general-purpose interface (I/F)  164  as components thereof. These components are communicatively connected with each other via an internal bus  166 . 
     Processor  150  is typically an arithmetic processing unit such as a central processing unit (CPU) or a multi processing unit (MPU). Processor  150  reads various programs including an OS installed in secondary storage device  154  and executes the various programs while deploying the various programs to main storage device  152 . 
     Main storage device  152  is typically a volatile storage medium such as a dynamic random access memory (DRAM) and holds codes of various programs including the OS executed by processor  150 , as well as various pieces of work data necessary for execution of the various programs. Secondary storage device  154  is a non-volatile storage medium such as a hard disk or a solid state drive (SSD) and holds various programs including an OS, as well as various setting values. 
     Communication interface  156  performs processing related to communications with the apparatus. Communication interface  156  is typically an interface for monitoring control apparatus  100  to communicate with target device  2  via network  4 . 
     Display  158  displays various pieces of information in accordance with an instruction of processor  150 . Input device  160  typically includes a keyboard, a mouse and the like, and accepts various settings and operations from the user. Input device  160  may include a touch panel. Speaker  162  converts an audio signal provided from processor  150  into a voice and then outputs the voice to the outside of monitoring control apparatus  100 . 
     General-purpose interface  164  typically includes a universal serial bus (USB) interface, an RS-232C-compliant serial communication interface, a parallel communication interface and the like, and exchanges data with an external device or the like. 
     Monitoring control apparatus  100  may further include a light emitting diode (LED) lamp or the like for notifying target device  2  of an occurring abnormality. 
     &lt;Alarm Screen&gt; 
       FIG. 3  shows an example alarm screen. Referring to  FIG. 3 , monitoring control apparatus  100  displays an alarm screen  300  in display  158 . Alarm screen  300  includes an alarm list  310 , a details display area  320 , and an associated display area  330 . Herein, target device  2  is a GCB in a transformer station. 
     Alarm screen  300  is an alarm screen assuming a case where an accident has occurred in a hydraulic actuator of the GCB. The GCB is filled with an SF 6  gas and adopts a manner of driving a puffer cylinder that forms a chamber referred to as a puffer chamber by the driving force of the hydraulic actuator, and spraying the SF 6  gas in the puffer chamber onto an arc generated between electrodes to extinguish the arc. 
     Alarm list  310  is list information for notifying the system operator of various abnormalities that have occurred in target device  2 . Alarm list  310  includes an index, an alarm name corresponding to an abnormality, a time of occurrence of an abnormality, and a status of an abnormality as main items. 
     In the example of  FIG. 3 , alarm display of a drop in the gas pressure of a tank filled with the SF 6  gas, drops in the oil pressure and oil level of the hydraulic actuator, a long-time operation of an electric motor that drives the hydraulic actuator, and an overcurrent of the electric motor are shown is performed as abnormalities that have occurred in the GCB. For example, a gas pressure drop alarm  311  with an index “5” indicates that a “gas pressure drop” “has occurred” at “10:36 on October 12”. It is assumed here that an abnormality has occurred in a flow as in (1) through (4) below. 
     (1) The oil pressure of the hydraulic actuator drops, and the gas pressure of the tank filled with the SF 6  gas drops, due to age-related deterioration. When the oil pressure of the hydraulic actuator has dropped due to oil leakage or the like, the hydraulic pump operates to increase the oil pressure. Monitoring control apparatus  100  determines that an oil pressure drop has occurred based on a signal from an oil pressure detection circuit provided in the hydraulic actuator, and determines that a gas pressure drop has occurred based on a signal from a gas pressure detection circuit provided in the tank. Monitoring control apparatus  100  displays gas pressure drop alarm  311  and an oil pressure drop alarm  312  in alarm list  310 . 
     (2) When the oil pressure of the hydraulic actuator has dropped due to oil leakage or the like, the hydraulic pump operates several times to increase the oil pressure, which increases the count of operations. The oil level also drops due to oil leakage or the like. Monitoring control apparatus  100  determines that the oil level has dropped based on a signal from an oil level detection circuit provided in the hydraulic actuator, and then displays an oil level drop alarm  313  in alarm list  310 . 
     (3) When the count of operations of the hydraulic pump increases, the operating time of the electric motor for driving the hydraulic pump increases. Monitoring control apparatus  100  determines that a long-time operation of an electric motor has occurred based on a signal from a detection circuit that detects a long-time operation of the electric motor, and then displays an electric motor long-time operation alarm  314  in alarm list  310 . 
     (4) As the operating time of the electric motor increases, an overcurrent occurs in the electric motor. Monitoring control apparatus  100  determines that an overcurrent has occurred in the electric motor based on a signal from an overcurrent detection circuit, and then displays an electric motor overcurrent alarm  315  in alarm list  310 . 
     In the example of  FIG. 3 , detailed information about a long-time operation of the electric motor is displayed in details display area  320  among a plurality of abnormalities shown in alarm list  310  that have occurred in the GCB. For example, monitoring control apparatus  100  accepts an input to select electric motor long-time operation alarm  314  from the system operator via input device  160 , thereby displaying detailed information about a long-time operation of the electric motor in details display area  320 . 
     Details display area  320  includes an alarm name  321  selected, a transition button  322  for transition to a schematic diagram, and a remedy contents group  323  for resolving an abnormality corresponding to the selected alarm (i.e., returning from the abnormality). Herein, “ELECTRIC MOTOR LONG-TIME OPERATION” is displayed as alarm name  321 . Remedy contents group  323  includes a first remedy content “CHECK OF OIL PRESSURE”, a second remedy content “CHECK OF OIL LEAKAGE”, and a third remedy content “CHECK OF NITROGEN LEAKAGE”. The system operator can select each of the first to third remedy contents to check more specific remedy contents (e.g., such as check of a sensor failure, replacement of a sensor). 
     Although the example of  FIG. 3  shows a configuration in which remedy contents group  323  includes three remedy contents, the present disclosure is not limited to this configuration. For example, it suffices that remedy contents group  323  includes one or more remedy contents. 
     As the system operator selects transition button  322 , a schematic diagram as shown in  FIG. 4  is displayed.  FIG. 4  shows an example of a display screen  400  of the schematic diagram. This schematic diagram includes a circuit element for detecting an abnormality “electric motor long-time operation”. Referring to  FIG. 4 , various contact circuits  21 ,  31 ,  41  to  43 ,  51 ,  61 , and indicators  23 ,  32 ,  44 ,  52 ,  62  are arranged as circuit elements in the schematic diagram shown in display screen  400 . Also, connecting lines L 1 , L 2  for connecting these circuit elements are arranged. 
     Contact circuit  21  closes contact  211  when detecting a power interruption of the hydraulic pump. Indicator  23  performs alarm display indicating the power interruption of the hydraulic pump when contact  211  is closed. Contact circuit  31  closes contact  231  when detecting an oil pressure drop of the hydraulic actuator. Indicator  32  performs alarm display indicating an oil pressure drop when contact  231  is closed. 
     Contact circuit  41  closes a contact  241  when detecting an overcurrent in an R phase among three phases of the electric motor. Similarly, contact circuit  42  closes a contact  242  when detecting an overcurrent in an S phase in the electric motor. Contact circuit  43  closes a contact  243  when detecting an overcurrent of a T phase of the electric motor. Indicator  44  performs alarm display indicating that an overcurrent has occurred in the electric motor when any of contacts  241  to  243  is closed (i.e., when an overcurrent has occurred in any one phase among the R phase to T phase of the electric motor). 
     Contact circuit  51  closes a contact  251  when detecting that the operating time of the electric motor is not less than a reference time (i.e., a long-time operation of the electric motor). Indicator  52  performs alarm display indicating a long-time operation of the electric motor when contact  251  is closed. Contact circuit  61  closes a contact  261  when detecting a phase interruption in any of the phases of the GCB. Indicator  62  performs alarm display indicating a phase interruption when contact  261  is closed. 
     Indicators  23 ,  32 ,  44 ,  52 ,  62  typically correspond to the respective LED lamps attached to a control panel of monitoring control apparatus  100 . Each indicator typically notifies the system operator of an abnormality by lighting up in the event of an abnormality. For example, indicator  32  lights up in the event of an oil pressure drop. The system operator can grasp what type of abnormality has occurred by checking a lighting indicator. In the event of an abnormality, an alarm corresponding to the abnormality is displayed on alarm screen  300  in display  158 . 
     Referring again to  FIG. 3 , an oil pressure drop alarm, an oil level drop alarm, and an electric motor overcurrent alarm are displayed in associated display area  330  as an associated alarm  332  associated with electric motor long-time operation alarm  314  selected by the system operator. This means that the abnormality “oil pressure drop alarm”, the abnormality “oil level drop”, and the abnormality “electric motor overcurrent” are extracted as associated abnormalities associated with the abnormality “electric motor long-time operation”. A manner of extracting an associated abnormality will be described below specifically. 
     Monitoring control apparatus  100  calculates levels of association of the abnormality “electric motor overcurrent”, the abnormality “oil level drop”, the abnormality “oil pressure drop”, and the abnormality “gas pressure drop”, corresponding to the other alarms included in alarm list  310 , with the abnormality “electric motor long-time operation” corresponding to electric motor long-time operation alarm  314  selected by the system operator. 
     Specifically, monitoring control apparatus  100  determines whether a condition A 1  is satisfied, where condition A 1  is a condition that a schematic diagram including a detection circuit for an abnormality X (herein, “electric motor long-time operation”) corresponding to the alarm selected by the system operator is identical to a schematic diagram including a detection circuit for the other abnormality. When condition A 1  is satisfied, it is conceivable that the degree of association of the other abnormality with abnormality X may be high. This is because the system operator wants to simultaneously check abnormality X and an abnormality which is highly likely to occur concomitantly with abnormality X, and accordingly, the detection circuits for these abnormalities are arranged in the same schematic diagram in many cases. 
     The schematic diagram shown in  FIG. 4  includes a detection circuit (e.g., contact circuit  51 ) for the abnormality “electric motor long-time operation”, a detection circuit (e.g., contact circuit  31 ) for the abnormality “oil pressure drop”, and detection circuits (e.g., contact circuit  41  to  43 ) for the abnormality “electric motor overcurrent”. In other words, the schematic diagram corresponding to the abnormality “electric motor long-time operation” is identical to the schematic diagrams corresponding to the abnormality “oil pressure drop” and the abnormality “electric motor overcurrent”. 
     Monitoring control apparatus  100  increases the level of association of each of the abnormality “oil pressure drop” and the abnormality “electric motor overcurrent” with the abnormality “electric motor long-time operation” by “1”. In contrast, the abnormality “oil level drop” and the abnormality “gas pressure drop” do not satisfy condition A 1 , and accordingly, the levels of association thereof are not increased. 
     Monitoring control apparatus  100  then determines whether a condition A 2  is satisfied, where condition A 2  is a condition that a target part for abnormality X is identical to a target part for the other abnormality. When condition A 2  is satisfied, it is conceivable that the degree of association of the other abnormality with abnormality X may be high. This is because abnormality X and the other abnormality are highly likely to occur concurrently when the target part for abnormality X is identical to the target part for the other abnormality. 
     The abnormality “electric motor overcurrent”, the abnormality “electric motor long-time operation”, the abnormality “oil level drop”, and the abnormality “oil pressure drop” are abnormalities in the hydraulic actuator and have the same target part. In contrast, the abnormality “gas pressure drop” is an abnormality in the gas tank filled with the SF 6  gas and has a target part different from the target parts for the above four abnormalities. 
     Monitoring control apparatus  100  increases the level of association of each of the abnormality “electric motor overcurrent”, the abnormality “oil level drop”, and the abnormality “oil pressure drop” with the abnormality “electric motor long-time operation” by “1”. In contrast, the abnormality “gas pressure drop” does not satisfy condition A 2 , and accordingly, the level of association thereof is not increased. 
     Monitoring control apparatus  100  then determines whether a condition A 3  is satisfied, where condition A 3  is a condition that a difference between a time of occurrence of abnormality X and a time of occurrence of the other abnormality is not more than a reference time (e.g., not more than one minute). When condition A 3  is satisfied, it is conceivable that the degree of association of the other abnormality with abnormality X may be high. This is because abnormality X and the other abnormality are highly likely to have occurred by the same cause when the time of occurrence of abnormality X and the time of occurrence of the other abnormality are close to each other. 
     As shown in  FIG. 3 , the time of occurrence of the abnormality “electric motor long-time operation” is 12:58 on October 12, and an abnormality that has occurred within one minute from this time of occurrence is only the abnormality “electric motor overcurrent”. 
     Monitoring control apparatus  100  increases the level of association of the abnormality “electric motor overcurrent” with the abnormality “electric motor long-time operation” by “1”. In contrast, the abnormality “gas pressure drop”, the abnormality “oil pressure drop”, and the abnormality “oil level drop” do not satisfy condition A 3 , and accordingly, the levels of association thereof are not increased. 
     Monitoring control apparatus  100  further determines whether a condition A 4  is satisfied, where condition A 4  is a condition that the remedy contents for the other abnormality are included in the remedy contents for abnormality X. When condition A 4  is satisfied, it is conceivable that the degree of association of the other abnormality with abnormality X may be high. This is because when the remedy contents for abnormality X are identical to those for the other abnormality, these abnormalities are highly likely to occur by the same cause. 
     Since the occurrence of abnormality X (herein, abnormality “electric motor long-time operation”) is caused by an oil pressure drop in many cases, it is basically aimed to restore an oil pressure. Thus, the remedy contents for the abnormality “electric motor overcurrent” include the first remedy content “check of oil pressure”, the second remedy content “check of oil leakage”, and the third remedy content “check of nitrogen leakage” as shown in  FIG. 3 . 
     Herein, the remedy contents for the abnormality “oil level drop” and the abnormality “oil pressure drop” are identical to the remedy contents for the abnormality “electric motor long-time operation”. In contrast, the remedy contents for the abnormality “electric motor overcurrent” are check of an abnormality of an electric motor and replacement of a part, and accordingly, none of these remedy contents are identical to the remedy contents for “electric motor long-time operation”. The remedy contents for the abnormality “gas pressure drop” include check of a gas pressure and the like, and accordingly, none of these remedy contents are identical to those for the abnormality “electric motor long-time operation”. 
     Monitoring control apparatus  100  increases the level of association of each of the abnormality “oil level drop” and the abnormality “oil pressure drop” with the abnormality “electric motor long-time operation” by “3”. In the case of condition A 4 , the levels of association are increased significantly compared with conditions A 1  to A 3 . When the remedy contents for abnormality X are identical to those for the other abnormality, these abnormalities are highly likely to be resolved by performing the remedy therefor. Since condition A 4  has a degree of importance higher than those of conditions A 1  to A 3 , in calculation of the level of association of each abnormality, the level of association is increased significantly when condition A 4  is satisfied. 
     The above has described the configuration in which the remedy contents for the abnormality “electric motor long-time operation” are completely identical to the remedy contents for the abnormality “oil level drop” and the abnormality “oil pressure drop”, but the present disclosure is not limited to this configuration. For example, when at least one remedy content for the other abnormality is included in a plurality of remedy contents for abnormality X, monitoring control apparatus  100  may determine that condition A 4  is satisfied. For example, when any of the first to third remedy contents for abnormality X is included in the remedy contents for the other abnormality, monitoring control apparatus  100  may determine that condition A 4  is satisfied. 
     Monitoring control apparatus  100  calculates a level of association of another abnormality with abnormality X based on conditions A 1  to A 4  described above. Since the abnormality “oil pressure drop” satisfies conditions A 1 , A 2 , A 4 , the level of association with the abnormality “electric motor long-time operation” is “5”. Since the abnormality “oil level drop” satisfies conditions A 2 , A 4 , the level of association is “4”. Since the abnormality “electric motor overcurrent” satisfies conditions A 1 , A 2 , A 3 , the level of association is “3”. Since the abnormality “gas pressure drop” satisfies none of conditions A 1  to A 4 , the level of association is “0”. 
     When the level of association of another abnormality is not less than a threshold, monitoring control apparatus  100  extracts the other abnormality as an associated abnormality associated with abnormality X. In the example of  FIG. 3 , this threshold is set at “1” (corresponds to “FILTER: LEVEL 1” in the figure). Monitoring control apparatus  100  thus extracts, as the associated abnormalities, the abnormality “oil level drop”, the abnormality “oil level drop”, and the abnormality “electric motor overcurrent”, each of which has a level of association of not less than “1” with the abnormality “electric motor long-time operation”. 
     Monitoring control apparatus  100  then displays associated alarm  332  (i.e., an oil pressure drop alarm, an oil level drop alarm, and an electric motor overcurrent alarm) for notifying the extracted associated abnormalities (i.e., oil pressure drop, oil level drop, and electric motor overcurrent). 
     For condition A 4 , monitoring control apparatus  100  may change a manner of increasing a level of association in accordance with a degree of coincidence of remedy contents. For example, when a plurality of remedy contents for abnormality X coincide with a plurality of remedy contents for another abnormality in three or more remedy contents, the level of association of the other abnormality with abnormality X is increased by “3”. When a plurality of remedy contents for abnormality X coincide with a plurality of remedy contents for another abnormality in two remedy contents, the level of association of the other abnormality with abnormality X may be increased by “2”. When a plurality of remedy contents for abnormality X coincide with a plurality of remedy contents for another abnormality in one remedy content, the level of association of the other abnormality with abnormality X may be increased by “1”. 
     (Other Display Examples of Alarm Screen) 
       FIGS. 5 and 6  are diagrams for illustrating other display examples of the alarm screen. Referring to  FIG. 5 , when a remedy for an abnormality is complete, monitoring control apparatus  100  displays an object (e.g., icon) indicating the completion of the remedy. In the example of  FIG. 5 , an object  325  indicating the completion of the first remedy content “check of oil pressure” for the abnormality “electric motor long-time operation” is displayed. When the associated abnormality (e.g., abnormality “oil pressure drop”) is resolved by a remedy for the abnormality or by another cause, the associated alarm corresponding to the resolved abnormality “oil pressure drop” is deleted from associated display area  330 . 
     Thus, the system operator can immediately check that remedy is complete, allowing a smooth shift to the next remedy without requiring a check operation. The system operator can also grasp in real time how many associated alarms are present, and accordingly, can determine the nature of an abnormality required to be handled. 
     Referring to  FIG. 6 , monitoring control apparatus  100  displays an entry for selecting any of levels of association “0” to “4” when accepting an input to select a filter  331  by the system operator. Monitoring control apparatus  100  displays a list of associated alarms not lower than the level of association selected by the system operator. Specifically, when level of association “4” is selected, monitoring control apparatus  100  extracts, as associated abnormalities, the abnormality “oil level drop” and the abnormality “oil level drop”, each of which has a level of association of not less than “4” with the abnormality “electric motor long-time operation”, and displays associated alarms corresponding to these associated abnormalities. The system operator can select an associated alarm to be displayed, depending on the situation, with the use of a filter. 
     &lt;Functional Configuration&gt; 
       FIG. 7  is a block diagram showing a functional configuration of monitoring control apparatus  100 . Referring to  FIG. 7 , monitoring control apparatus  100  includes a signal receiver  501 , a display controller  503 , a selector  505 , a degree-of-association calculator  507 , and an extractor  509  as the main functional configuration. Each of these functions is implemented by, for example, processor  150  executing a program stored in secondary storage device  154 . In an alternative configuration, some or all of these functions may be implemented by hardware. 
     Signal receiver  501  receives various signals transmitted from target device  2 . Signal receiver  501  typically receives abnormal signals detected by the various detection circuits provided in target device  2 . 
     Display controller  503  displays an alarm screen (e.g., alarm screen  300  of  FIG. 3 ) for notifying a plurality of abnormalities that have occurred in monitoring target device  2 , based on the received various abnormal signals. 
     Selector  505  selects any abnormality X among the plurality of abnormalities that have occurred in monitoring target device  2 . Selector  505  typically selects any abnormality X from among the plurality of abnormalities displayed on alarm screen  300 , in accordance with an instruction by a user (e.g., system operator) via input device  160 . Display controller  503  displays detailed information about the selected abnormality X on alarm screen  300 . In the example of  FIG. 3 , the detailed information on the selected abnormality “electric motor long-time operation” is displayed in details display area  320 . 
     For each of one or more other abnormalities except for abnormality X among the plurality of abnormalities, degree-of-association calculator  507  calculates a degree of association (e.g., level of association) of the other abnormality with abnormality X based on a plurality of conditions (e.g., conditions A 1  to A 4 ). In the example of  FIG. 3 , degree-of-association calculator  507  calculates a degree of association of each of the abnormality “gas pressure drop”, the abnormality “oil pressure drop”, the abnormality “oil level drop”, and the abnormality “electric motor overcurrent” with the abnormality “electric motor long-time operation”. 
     In an aspect, when condition A 1  that a schematic diagram including a detection circuit for abnormality X is identical to a schematic diagram including a detection circuit for another abnormality is satisfied, degree-of-association calculator  507  increases the degree of association of the other abnormality with abnormality X by a reference value E 1  (e.g., “1”). Also, when condition A 2  that the target part for abnormality X is identical to the target part for another abnormality is satisfied, degree-of-association calculator  507  increases the degree of association of the other abnormality with abnormality X by reference value E 1 . Further, when condition A 3  that a difference between a time of occurrence of abnormality X and a time of occurrence of another abnormality is not more than a reference time (e.g., not more than one minute) is satisfied, degree-of-association calculator  507  increases the degree of association of the other abnormality with abnormality X by reference value E 1 . 
     In another aspect, when condition A 4  that at least one remedy content for another abnormality is included in at least one remedy content for abnormality X is satisfied, degree-of-association calculator  507  increases the degree of association of the other abnormality with abnormality X by a reference value E 2  (e.g., “3”) greater than reference value E 1 . 
     When the degree of association of another abnormality is not less than a threshold Th, extractor  509  extracts the other abnormality as an associated abnormality associated with abnormality X. Threshold Th can be changed appropriately by selecting filter  331  displayed on alarm screen  300 . For example, when “1” is selected in filter  331 , threshold Th is “1”. 
     Display controller  503  displays associated alarm  332  for notifying the associated abnormality extracted by extractor  509  in associated display area  330  of alarm screen  300 . 
     &lt;Procedure&gt; 
       FIG. 8  shows an example procedure of monitoring control apparatus  100 . The flowchart of  FIG. 8  shows a procedure of displaying an associated alarm. Each step below is typically performed by processor  150  of monitoring control apparatus  100 . 
     Referring to  FIG. 8 , processor  150  displays alarm list  310  on alarm screen  300  based on an abnormal signal received from target device  2  (step S 10 ). Processor  150  receives an input to select any alarm of alarm list  310  via input device  160  (step S 12 ). Processor  150  calculates a level of association of another abnormality with abnormality X corresponding to the selected alarm (step S 14 ). 
     Processor  150  extracts an associated abnormality of abnormality X (step S 16 ). Specifically, when the level of association of the other abnormality with abnormality X is not less than threshold Th, processor  150  extracts the other abnormality as an associated abnormality. Processor  150  displays associated alarm  332  corresponding to the associated abnormality on alarm screen  300  (step S 18 ), and then ends the processing. 
     Advantageous Effects 
     Monitoring control apparatus  100  according to the present embodiment appropriately notifies the association among a plurality of abnormalities that have occurred in target device  2 . In the event that a plurality of abnormalities have occurred in target device  2 , thus, the system operator can immediately grasp a degree of association between an abnormality and another abnormality. Since an abnormality highly associated with an abnormality corresponding to an alarm selected by the system operator is displayed automatically, an improvement in operation efficiency for an abnormality is expected. Since the remedy contents for abnormalities are displayed in the details display area, the system operator can immediately grasp a remedy required for the occurring abnormality. 
     Other Embodiment 
     The above embodiment has described the case where target device  2  is a GCB, but target device  2  may be any other device. An example display of an alarm screen when target device  2  is a transformer will be described as another example. 
       FIG. 9  shows an example alarm screen according to another embodiment. Referring to  FIG. 9 , monitoring control apparatus  100  displays an alarm screen  350  on display  158 . Alarm screen  350  includes alarm list  310 , details display area  320 , and associated display area  330 . Herein, target device  2  is a transformer in a transformer station. 
     Alarm screen  350  is an alarm screen assuming a case where an accident has occurred in a transformer. In the example of  FIG. 9 , an overcurrent in a transformer, detection of gas in the transformer, any abnormality (corresponding to “LR abnormality” in the figure) in a tap changer, an operation of a pressure relief valve in a transformer, and incomplete tap changing are displayed as abnormalities that have occurred in the transformer. For example, each type of abnormality occurs in the flow as in (1) through (5) below. 
     (1) An overcurrent relay in a transformer operates due to a short-circuit accident. Monitoring control apparatus  100  determines that an overcurrent has occurred based on a signal from the overcurrent relay and displays an overcurrent alarm  361  in alarm list  310 . 
     (2) Cracked gas is detected, which has occurred in pyrolysis of insulating oil and insulator due to local overheating, discharging or the like in the transformer. Monitoring control apparatus  100  determines that cracked gas has occurred based on a signal from a gas detection circuit and displays a gas detection alarm  362  in alarm list  310 . 
     (3) Any abnormality occurs in a tap changer. Monitoring control apparatus  100  determines that the abnormality has occurred based on a signal from the tap changer and displays an LR abnormality alarm  363  in alarm list  310 . 
     (4) The generation of cracked gas increases the pressure in the transformer, thus operating the pressure relief valve. Monitoring control apparatus  100  displays a pressure relief valve operation alarm  364  in alarm list  310  based on an operation signal of the pressure relief valve. 
     (5) Incomplete tap changing occurs when a tap cannot be changed within a certain period of time. Based on a signal indicating the occurrence of incomplete tap changing, monitoring control apparatus  100  displays an incomplete tap changing alarm  365  in alarm list  310 . 
     Detailed information corresponding to the abnormality “pressure relief valve operation” is displayed in details display area  320 . Remedy contents group  323  corresponding to the abnormality “pressure relief valve operation” includes a first remedy content “stop of transformer operation”, a second remedy content “analysis of gas”, and a third remedy content “internal inspection”. 
     Monitoring control apparatus  100  calculates the level of association of each of the abnormality “overcurrent”, the abnormality “gas detection”, the abnormality “LR”, and the abnormality “incomplete tap changing” with the abnormality “pressure relief valve operation” based on conditions A 1  to A 4  described above. 
     For example, the abnormality “overcurrent” and the abnormality “gas detection” satisfy conditions A 1 , A 2 , and accordingly, the levels of association thereof with the abnormality “pressure relief valve operation” are “2”. The abnormality “LR” satisfies condition A 3 , and accordingly, the level of association thereof is “1”. The abnormality “incomplete tap changing” satisfies none of conditions A 1  to A 4 , and accordingly, the level of association thereof is “0”. 
     Monitoring control apparatus  100  extracts other abnormalities, each having a level of association of not less than “2”, based on the calculation result of the level of association, and displays associated alarm  332  corresponding to the extracted other abnormalities in associated display area  330 . In the example of  FIG. 9 , this threshold is set at “2” (corresponding to “FILTER: “LEVEL 2” in the figure). Monitoring control apparatus  100  thus displays a gas detection alarm and an overcurrent alarm as the associated alarms. 
     Each of the configurations illustrated as the embodiments described above is an example of the configuration of the present disclosure, and it can be combined with another known technique, or can be modified, for example partially omitted, within the scope not departing from the gist of the present disclosure. Further, in each embodiment described above, the process or the configuration described in the other embodiment may be employed and implemented as appropriate. 
     It should be understood that the embodiments disclosed herein are illustrative and non-restrictive in every respect. The scope of the present disclosure is defined by the scope of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the scope of the claims. 
     INDUSTRIAL APPLICABILITY 
       2  monitoring target device;  4  network;  21 ,  31 ,  41 ,  42 ,  43 ,  51 ,  61  contact circuit;  23 ,  32 ,  44 ,  52 ,  62  indicator;  100  monitoring control apparatus; 150 processor;  152  main storage device;  154  secondary storage device;  156  communication interface;  158  display;  160  input device;  162  speaker;  164  general-purpose interface;  166  internal bus;  300 ,  350  alarm screen;  310  alarm list;  320  details display area;  323  remedy contents group;  330  associated display area;  332  associated alarm;  400  display screen;  501  signal receiver;  503  display controller;  505  selector; 507 degree-of-association calculator;  509  extractor.