Abstract:
An EMS ( 30 ) is equipped with a control unit ( 31 ) for obtaining a first measurement value which indicates an operating state of an apparatus ( 11 ) at a predetermined time point and at least one second measurement value which indicates an operating state of the apparatus ( 11 ) at a time point earlier than the predetermined time point. The control unit ( 31 ) calculates a first reference value, which indicates a reference for the operating state of the apparatus ( 11 ), by using the second measurement value and determines the presence/absence of an anomaly of the apparatus ( 11 ) on the basis of a comparison result between the first measurement value and the first reference value.

Description:
TECHNICAL FIELD 
       [0001]    The present invention relates to an equipment management system, an equipment management apparatus, and an equipment management method for the management of equipment installed in a consumer&#39;s facility of grid power. 
       BACKGROUND ART 
       [0002]    In recent years, distributed power sources, such as a photovoltaic power generator, a storage battery apparatus, and a fuel cell, are being introduced in consumer&#39;s facilities of grid power. An equipment management apparatus that manages loads and distributed power sources (hereinafter, referred to as “equipment”) installed in the consumer&#39;s facilities are also known. An equipment management apparatus especially for homes is referred to as a home energy management system (HEMS). 
         [0003]    The equipment management apparatus monitors numerical values indicating an operation state of the equipment (e.g., power consumption), and determines an occurrence or a non-occurrence of an error of the equipment. Specifically, the equipment management apparatus determines an occurrence or a non-occurrence of an error of the equipment based on a comparison result between a measured value and a reference value of power consumption using, for example, a power consumption value of the equipment on a catalog or the like issued by a manufacturer as the reference value (see, for example, Patent Literature 1). 
       CITATION LIST 
     Patent Literature 
       [0004]    [Patent Literature 1] Japanese Patent Application Publication No. 2012-134837 
       SUMMARY OF INVENTION 
       [0005]    However, since different users use the equipment in different ways, the measured value of power consumption of the equipment can deviate from the reference value on a catalog or the like. In that case, if the equipment management apparatus uses the reference value on the catalog or the like, there is possibility that an error of the equipment is not detected accurately. 
         [0006]    Then, an object of the present invention is to provide an equipment management system, an equipment management apparatus, and an equipment management method capable of detecting an error of equipment accurately. 
         [0007]    An equipment management system according to a first feature includes: an equipment management apparatus that manages equipment provided in a consumer&#39;s facility, wherein the equipment management apparatus comprises a first controller that acquires a first measured value indicating an operation state of the equipment at first timing and a second measured value indicating an operation state of the equipment at second timing prior to the first timing; the first controller calculates a first reference value indicating a standard of the operation state of the equipment using the second measured value; and the first controller determines an occurrence or a non-occurrence of an error of the equipment based on a comparison result between the first measured value and the first reference value. 
         [0008]    In the first feature, the first controller calculates the first reference values for each of operation conditions of the equipment; and the first controller determines the occurrence or the non-occurrence of the error of the equipment based on a comparison result between the first measured value and the first reference value corresponding to a predetermined operation condition, when the first measured value is measured during an operation of the equipment according to the predetermined operation condition. 
         [0009]    In the first feature, the equipment management system includes: a higher-order management apparatus that manages a plurality of equipment management apparatuses, wherein the higher-order management apparatus comprises a second controller that acquires, about each of a plurality of equipments managed by any of the plurality of equipment management apparatuses, a third measured value indicating the operation state at second timing, and a fourth measured value indicating an operation state acquired at timing prior to the second timing; the second controller calculates a second reference value indicating a standard of the operation state for each equipment type of a plurality of equipments using the fourth measured value regarding the equipment of the same equipment type among a plurality of equipments; and the second controller determines an occurrence or a non-occurrence of an error of the predetermined equipment based on a comparison result between the third measured value about the predetermined equipment included in the plurality of equipments and the second reference value corresponding to the equipment type of the predetermined equipment. 
         [0010]    In the first feature, the second controller calculates the second reference value for each operation condition of the plurality of equipments; and the second controller determines the occurrence or the non-occurrence of the error of the predetermined equipment based on a comparison result between the third measured value about the predetermined equipment and the second reference value corresponding to the equipment type and the predetermined operation conditions of the predetermined equipment, when the third measured value about the predetermined equipment is measured during an operation of the predetermined equipment according to the predetermined operation conditions. 
         [0011]    In the first feature, the second controller calculates the second reference value for each operation condition of the plurality of equipments and for each installation environment of the plurality of equipments; and the second controller determines the occurrence or the non-occurrence of the error of the predetermined equipment based on a comparison result between the third measured value about the predetermined equipment and the second reference value corresponding to the equipment type, the predetermined operation conditions and a predetermined installation environment of the predetermined equipment, when the third measured value about the predetermined equipment is measured during an operation of the predetermined equipment according to the predetermined operation conditions and in the predetermined installation environment. 
         [0012]    In the first feature, the second controller determines that the error has occurred in the predetermined equipment if a difference between the third measured value about the predetermined equipment and the second reference value corresponding to the equipment type of the predetermined equipment, the predetermined operation conditions, and the predetermined installation environment exceeds a threshold value, when the third measured value about the predetermined equipment is measured during an operation of the predetermined equipment according to the predetermined operation conditions and in the predetermined installation environment. 
         [0013]    An equipment management apparatus according to a second feature manages equipment provided in a consumer&#39;s facility, includes a first controller that acquires a first measured value indicating an operation state of the equipment at predetermined timing, and a second measured value indicating an operation state of the equipment at timing prior to the predetermined timing, wherein the first controller calculates a first reference value indicating a standard of the operation state of the equipment using the second measured values; and the first controller determines an occurrence or a non-occurrence of an error of the equipment based on a comparison result between the first measured value and the first reference value. 
         [0014]    An equipment management method according to a third feature is a method of an equipment management apparatus that manages equipment provided in a consumer&#39;s facility. The equipment management method includes the steps of acquiring a first measured value indicating an operation state of the equipment at predetermined timing, and a second measured value indicating an operation state of the equipment at timing prior to the predetermined timing; calculating a first reference value indicating a standard of an operation state of the equipment using the second measured value; and determining an occurrence or a non-occurrence of an error of the equipment based on a comparison result between the first measured value and the first reference value. 
         [0015]    According to the present invention, provided are an equipment management system, an equipment management apparatus, and an equipment management method capable of detecting an error of equipment accurately. 
     
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         [0016]      FIG. 1  is a diagram of an equipment management system according to the present embodiment. 
           [0017]      FIG. 2  is a block diagram of an EMS according to the present embodiment. 
           [0018]      FIG. 3  is a diagram illustrating a table stored in a storage of the EMS according to the present embodiment. 
           [0019]      FIG. 4  is a sequence diagram of an equipment management method according to the present embodiment. 
           [0020]      FIG. 5  is a block diagram of a CEMS according to a first modification. 
           [0021]      FIG. 6  is a diagram illustrating a table stored in a storage of the CEMS according to the first modification. 
           [0022]      FIG. 7  is a sequence diagram of an equipment management method according to the first modification. 
           [0023]      FIG. 8  is a diagram illustrating a table stored in a storage of a CEMS according to a second modification. 
           [0024]      FIG. 9  is a diagram illustrating a table stored in a storage of a CEMS according to the third modification. 
       
    
    
     DESCRIPTION OF EMBODIMENTS 
       [0025]    Hereinafter, an equipment management system, an equipment management apparatus, and an equipment management method according to embodiments of the present invention will be described with reference to the drawings. In the following drawings, identical or similar components are denoted by identical or similar reference numerals. 
         [0026]    It should be understood that the drawings are schematic only and the ratio of dimensions is not to scale. Therefore, specific dimensions should be determined with reference to the description below. It is needless to mention that different relationships and ratio of dimensions may be included in different drawings. 
       Outline of the Embodiments 
       [0027]    An equipment management system according to embodiment includes: an equipment management apparatus that manages equipment provided in a consumer&#39;s facility, wherein the equipment management apparatus comprises a first controller that acquires a first measured value indicating an operation state of the equipment at first timing and a second measured value indicating an operation state of the equipment at second timing prior to the first timing; the first controller calculates a first reference value indicating a standard of the operation state of the equipment using the second measured value; and the first controller determines an occurrence or a non-occurrence of an error of the equipment based on a comparison result between the first measured value and the first reference value. 
         [0028]    The equipment management system according to the embodiment sets the first reference value calculated using the measured value indicating the operation state of the equipment to be basis during the determination of the occurrence or the non-occurrence of the error of the equipment. Thus, the equipment management system according to the embodiment is capable of detecting the error of the equipment accurately. 
       Embodiments 
     (Equipment Management System) 
       [0029]    Hereinafter, an equipment management system according to the present embodiment will be described.  FIG. 1  is a diagram illustrating an equipment management system  100  according to the present embodiment. 
         [0030]    As illustrated in  FIG. 1 , the equipment management system  100  includes a consumer&#39;s facility  10 , a CEMS  20 , and a network server  40 . The consumer&#39;s facility  10  receives power supply from a grid  50 . The consumer&#39;s facility  10 , the CEMS  20 , and the network server  40  are connected by a network  60 . 
         [0031]    In the present embodiment, the consumer&#39;s facility  10  includes an equipment  11  and an EMS  30 . The equipment  11  includes distributed power sources that output generated or stored power, and loads that consume the power. The distributed power sources include, for example, fuel cell apparatuses, such as a photovoltaic power generation (PV) apparatus, a solid oxide fuel cell (SOFC), or a polymer electrolyte fuel cell (PEFC), and a storage battery apparatus. The loads include, for example, such apparatuses as a refrigerator, a freezer, a lighting, and an air conditioner. The EMS  30  is an exemplary equipment management apparatus that manages the equipment  11 . One or a plurality of the equipment  11  may be provided. The configuration of the EMS  30  will be described later. 
         [0032]    The consumer&#39;s facility  10  may be a detached house, a shop, such as a convenience store and a supermarket, a commercial facility, such as a commercial building, and a factory. 
         [0033]    In the present embodiment, a consumer group  10 A, a consumer group  10 B, and a consumer group  10 C are constituted by a plurality of consumer&#39;s facilities  10 . The consumer group  10 A, the consumer group  10 B, and the consumer group  10 C are classified, for example, geographically. The consumer group  10 A, the consumer group  10 B, and the consumer group  10 C may, for example, be an apartment house, such as a condominium. 
         [0034]    The CEMS  20  controls interconnection between a plurality of consumer&#39;s facilities  10  and the grid  50 . The CEMS  20  manages a plurality of consumer&#39;s facilities  10  and is therefore referred to as a cluster/community energy management system (CEMS). In particular, the CEMS  20  disconnects a plurality of consumer&#39;s facilities  10  from the grid  50  during an outage or the like. On the other hand, the CEMS  20  interconnects a plurality of consumer&#39;s facilities  10  and the grid  50  during power recovery or the like. 
         [0035]    In the present embodiment, a CEMS  20 A and a CEMS  20 B are provided as the CEMS  20 . The CEMS  20 A controls, for example, interconnection between the consumer&#39;s facilities  10  included in the consumer group  10 A and the grid  50 . The CEMS  20 B controls, for example, interconnection between the consumer&#39;s facilities  10  included in the consumer group  10 B and the grid  50 . Since no CEMS is provided corresponding to the consumer group  10 C in the present embodiment, the EMS  30 , for example, provided in the consumer&#39;s facilities  10  included in the consumer group  10 C controls interconnection between the consumer&#39;s facilities  10  and the grid  50 . 
         [0036]    The network server  40  collectively manages the consumer&#39;s facilities  10  included in the consumer group  10 A, the consumer group  10 B, and the consumer group  10 C. The network server  40  stores information about the consumer&#39;s facilities  10  acquired, for example, from the CEMS  20  or a HEMS  30 . 
         [0037]    The grid  50  supplies power generated by a power plant to the consumer&#39;s facilities  10  via substations, power lines, and the like. 
         [0038]    The network  60  is connected to each apparatus via signal lines. The network  60  is, for example, the Internet, a broadband communication network, a narrowband communication network, or a portable telephone network. 
       (Configuration of EMS) 
       [0039]    Hereinafter, the EMS according to the present embodiment will be described.  FIG. 2  is a block diagram of the EMS  30  according to the present embodiment.  FIG. 3  is a diagram illustrating a table stored in a storage  33  of the EMS  30  according to the present embodiment. 
         [0040]    As illustrated in  FIG. 2 , the EMS  30  includes a controller  31 , a communication unit  32 , the storage  33 , and a display unit  34 . 
         [0041]    The controller  31  controls the communication unit  32 , the storage  33 , and the display unit  34 . 
         [0042]    In the present embodiment, the controller  31  acquires information about the equipment  11 . The information about the equipment  11  includes, for example, an identification number of the equipment  11 . The controller  31  may acquire information about the equipment  11  in a format based on communication protocols, such as the ECHONET Lite (registered trademark) or the Zig Bee (registered trademark), when the equipment  11  is connected to a new EMS  30  via a signal line. Alternatively, the controller  31  may request the equipment  11  to transmit information about the equipment  11 . 
         [0043]    In the present embodiment, the controller  31  acquires a measured value indicating an operation state of the equipment  11  (hereafter, a “measured value”). The measured value about the equipment  11  may, for example, be energy consumption (e.g., power consumption) of the equipment  11 , or power generated or discharged by the equipment  11 . The controller  31  may acquire the measured value from the equipment  11 , or may acquire the measured value from, for example, a sensor provided separately from the equipment  11 . The controller  31  may acquire the measured value about the equipment  11  periodically. Alternatively, the controller  31  may request the equipment  11  to transmit the measured value. 
         [0044]    The communication unit  32  transmits and receives various signals to and from the equipment  11  via a signal line. In the present embodiment, the communication unit  32  receives information about the equipment  11 . The controller  31  may control the equipment  11  using a signal based on communication protocols, such as the ECHONET Lite (registered trademark). The communication unit  32  may transmit information about the equipment  11  to the CEMS  20  via a signal line. 
         [0045]    The storage  33  stores information about the equipment  11  acquired by the controller  31 . When the controller  31  acquires the measured value about the equipment  11 , the storage  33  stores the measured value acquired by the controller  31  together with the measured value acquired previously by the controller  31 . 
         [0046]    As illustrated in  FIG. 3 , the storage  33  has a table that stores information about the equipment  11 . The storage  33  stores, for example, information about the equipment  11  (e.g., an identification number) and a later-described first reference value about the equipment  11  in association with each other. 
         [0047]    The display unit  34  visualizes and displays various types of information stored in the EMS  30  by an application. The display unit  34  may include a manipulation unit, such as a touchscreen. In that case, a user may input information for controlling the equipment  11  via the manipulation unit. 
       (Determination About Occurrence or Non-Occurrence of Error) 
       [0048]    Hereinafter, determination about an occurrence or a non-occurrence of an error of the equipment by the EMS according to the present embodiment will be described. 
         [0049]    The controller  31  acquires a first measured value indicating an operation state of the equipment  11  at predetermined timing, and a second measured value indicating an operation state of the equipment  11  at timing prior to the predetermined timing. Specifically, the first measured value is one of the measured values about the equipment  11  and, preferably, is the latest measured value at the time of determining an occurrence or a non-occurrence of an error of the equipment  11 . The second measured values are all the measured values about the equipment  11  acquired, for example, prior to the predetermined timing at which the first measured value is measured. 
         [0050]    The controller  31  calculates a first reference value indicating a standard of the operation state of the equipment using the second measured values. Specifically, the controller  31  may calculate an average value of the second measured values, and use the calculated average value as the first reference value. Alternatively, after excluding values determined as outliers of the second measured values based on the average value, standard deviation, or the like, the controller  31  may calculate the average value of the second measured values and use the calculated average value as the first reference value. Alternatively, the controller  31  may classify the second measured values by time period, and calculate the first reference value for each time period. The storage  33  stores the first reference value in association with the information about the equipment  11 . 
         [0051]    The controller  31  may calculate the first reference value each time it acquires the measured value about the equipment  11 . Alternatively, the controller  31  may calculate the first reference value periodically. 
         [0052]    In the present embodiment, the controller  31  compares the first measured value with the first reference value. The controller  31  determines an occurrence or a non-occurrence of an error of the equipment  11  based on a comparison result between the first measured value and the first reference value. For example, the controller  31  determines that an error has occurred in the equipment  11  in a case where a difference between the measured value and the first reference value exceeds a threshold value. 
         [0053]    If the controller  31  determines that an error has occurred in the equipment  11 , the controller  31  may display a message notifying an occurrence of an error of the equipment  11  on the display unit  34 . Alternatively, if the controller  31  determines that an error has occurred in the equipment  11 , the controller  31  may transmit an equipment stop signal for stopping operation of the equipment  11  to the equipment  11  via the communication unit  32 . 
         [0054]    In the present embodiment, the controller  31  may acquire operation conditions (e.g., heating, temperature a 1 , an air volume b 1 , and the like) of the equipment  11  in addition to the measured value about the equipment  11 . In that case, the storage  33  stores the measured value about the equipment  11  for each operation condition. 
         [0055]    In a case where the controller  31  acquires the operation conditions of the equipment  11  in addition to the measured value about the equipment  11 , the controller  31  calculates the first reference value for each operation condition. The storage  33  stores the first reference value in association with the information and the operation conditions about the equipment  11 . 
       (Equipment Management Method) 
       [0056]    Hereinafter, an equipment management method according to the present embodiment will be described.  FIG. 4  is a sequence diagram of the equipment management method according to the present embodiment. 
         [0057]    In step S 10 , the EMS  30  stores information about the equipment  11  (e.g., the equipment type). Here, the information about the equipment  11  may be transmitted to the EMS  30  from the equipment  11  when the equipment  11  is newly connected to the EMS  30  via a signal line. Alternatively, the EMS  30  may request the equipment  11  to transmit the information about the equipment. 
         [0058]    In step S 20 , the EMS  30  acquires the measured value about the equipment  11  and stores the acquired measured value. Here, the EMS  30  may acquire the measured value from the equipment  11 , or may acquire the measured value from a sensor or the like provided separately from the equipment  11 . The EMS  30  may perform the process of step S 20  periodically (e.g., each one minute), or may perform the process of step S 20  when the EMS  30  requests the equipment  11  to transmit the measured value. 
         [0059]    In step S 30 , the EMS  30  calculates the first reference value. Specifically, the EMS  30  refers to the stored measured value, and sets a measured value indicating the operation state of the equipment  11  at predetermined timing to be the first measured value, and sets a of measured values representing the operation state of the equipment  11  at timing prior to the predetermined timing to be the second measured value. The EMS  30  calculates the first reference value indicating the standard of the operation state of the equipment using the second measured value. The process of step S 30  may be performed in succession to step S 20  or may be performed periodically (e.g., each 15 minutes). 
         [0060]    In step S 40 , the EMS  30  compares the first measured value with the first reference value. In step S 50 , the EMS  30  determines an occurrence or a non-occurrence of an error of the equipment  11  based on a comparison result between the first measured value and the first reference value. In a case where the EMS  30  determines that an error has occurred in the equipment  11 , the EMS  30  performs the process of step S 60 . 
         [0061]    In step S 60 , the EMS  30  transmits, for example, an equipment stop signal for stopping the equipment  11  to the equipment  11 . Alternatively, the EMS  30  may display a message notifying a user of an occurrence of an error of the equipment  11 . 
         [0062]    Here, in step S 20 , in a case where the EMS  30  acquires the operation conditions in addition to the measured value about the equipment  11 , the EMS  30  stores the measured value about the equipment  11  for each operation condition. In step S 30 , the EMS  30  calculates the first reference value about the equipment  11  for each operation condition. 
         [0063]    As described above, the EMS  30  calculates the first reference value using the measured value about the equipment  11 . The EMS  30  updates the first reference value by repeating the process of step S 20 . Therefore, since the EMS  30  uses the first reference value suitable to the usage status of the equipment  11  for the determination of an occurrence or a non-occurrence of an error, the EMS  30  can detect an error of the equipment  11  accurately. 
       First Modification 
       [0064]    Hereinafter, an equipment management system according to a first modification of the present embodiment will be described mainly with reference to differences from the equipment management system according to the present embodiment.  FIG. 5  is a block diagram illustrating a CEMS  20  according to the first modification.  FIG. 6  is a diagram illustrating a table stored in a storage  23  of the CEMS  20  according to the first modification.  FIG. 7  is a sequence diagram of the equipment management method according to the first modification. 
         [0065]    As illustrated in  FIG. 5 , the CEMS  20  includes a controller  21 , a communication unit  22 , and a storage  23 . 
         [0066]    The controller  21  controls the communication unit  22  and the storage  23 . 
         [0067]    In the first modification, the controller  21  acquires information about each of a plurality of equipments  11  managed by any of a plurality of EMSs  30  (hereinafter, referred to as “equipment  11 ”). Information about the equipment  11  includes the equipment type (e.g., an air conditioner  1 ). 
         [0068]    In the first modification, the controller  21  acquires a measured value indicating an operation state about the equipment  11  managed by any of a plurality of EMSs  30 . Specifically, the controller  21  acquires a third measured value indicating the operation state about the equipment  11  at predetermined timing, and a fourth measured value indicating the operation state acquired at timing prior to the predetermined timing. The third measured value is one of the measured values about the equipment  11  and, preferably, is the latest measured value at the time of determining an occurrence or a non-occurrence of an error of the equipment  11 . The fourth measured values are, for example, all the measured values about the equipment  11  acquired prior to the predetermined timing at which the third measured value is measured. 
         [0069]    The communication unit  22  transmits and receives various signals to and from the EMS  30  via a signal line. In the present embodiment, the communication unit  22  receives information about the equipment  11  from the EMS  30 . The communication unit  22  may transmit and receive various signals to and from the network server  40  via the network  60 . 
         [0070]    The storage  23  stores the measured value about the equipment  11  acquired by the controller  21 . That is, when the controller  21  acquires the measured value about the equipment  11 , the storage  23  stores the measured value acquired by the controller  21  in addition to the measured value acquired previously by the controller  21 . 
         [0071]    As illustrated in  FIG. 6 , the storage  23  includes a table that stores information about the equipment  11 . The storage  23  stores the equipment type of the equipment  11  and a later-described second reference value about the equipment  11  in association with each other. 
         [0072]    In the first modification, the controller  21  calculates the second reference value indicating the standard of the operation state for each equipment type of a plurality of equipments using the fourth measured value regarding the equipment of the same equipment type among a plurality of equipments. The storage  23  stores the second reference value about the equipment  11  in association with the equipment type of the equipment  11 . 
         [0073]    In the first modification, the controller  21  determines an occurrence or a non-occurrence of an error of predetermined equipment (i.e., the equipment  11 ) based on a comparison result between the third measured value about the predetermined equipment included in a plurality of equipments and the second reference value corresponding to the equipment type of the predetermined equipment. For example, the controller  31  determines that an error has occurred in the equipment  11  if a difference between the third measured value and the second reference value exceeds a threshold value. In a case where the controller  21  determines that an error has occurred in the equipment  11 , the controller  21  notifies the EMS  30  of the error of the equipment  11 . 
         [0074]    Hereinafter, an equipment management method according to the first modification of the present embodiment will be described.  FIG. 7  is a sequence diagram of the equipment management method according to the first modification. 
         [0075]    In step S 110 , the EMS  30  stores information about the equipment  11 . Next, in step S 120 , the CEMS  20  stores information about the equipment  11 . The process of step S 120  is performed in succession to, for example, the process of step S 110 . 
         [0076]    In step S 130 , the EMS  30  acquires the measured value about the equipment  11  and stores the acquired measured value. Next, in step S 140 , the CEMS  20  acquires the measured value about the equipment  11  and stores the acquired measured value. The process of step S 140  is performed in succession to, for example, the process of step S 130 . 
         [0077]    In step S 150 , the CEMS  20  calculates the second reference value. Specifically, with reference to the stored measured value, the CEMS  20  sets the measured value indicating the operation state at predetermined timing to be the third measured value, and sets a measured value indicating the operation state at timing prior to the predetermined timing to be the fourth measured value, regarding the equipment  11  managed by any of a plurality of EMSs  30 . The CEMS  20  calculates the second reference value indicating the standard of the operation state for each equipment type of a plurality of equipments using the fourth measured value regarding the equipment of the same equipment type among a plurality of equipments. The process of step S 150  may be performed in succession to step S 140  or may be performed periodically (e.g., each 15 minutes). 
         [0078]    In step S 160 , the CEMS  20  compares the third measured value about predetermined equipment included in a plurality of equipments and the second reference value corresponding to the equipment type of the predetermined equipment. In step S 170 , the CEMS  20  determines an occurrence or a non-occurrence of an error of the predetermined equipment based on the comparison result in step S 160 . In a case where the CEMS  20  determines that an error has occurred in the predetermined equipment, the CEMS  20  performs the process of step S 180 . 
         [0079]    In step S 180 , the CEMS  20  transmits an error detection notification about the predetermined equipment to the EMS  30  that manages the predetermined equipment. The EMS  30  that has received the error detection notification transmits, for example, an equipment stop signal for stopping the equipment  11  to the predetermined equipment in step S 190 . Alternatively, the EMS  30  may display a message notifying a user of an occurrence of an error about the predetermined equipment. 
         [0080]    As described above, in the equipment management system according to the first modification of the present embodiment, the CEMS  20  acquires, from a plurality of EMSs  30 , the measured value about the equipment  11  managed by each EMS  30 . The CEMS  20  calculates the second reference value for each equipment type and uses the calculated second reference value for the determination of an occurrence or a non-occurrence of an error of the equipment  11 . 
         [0081]    The CEMS  20  calculates the second reference value for each equipment type using the measured value about the equipment  11  acquired from a plurality of EMSs  30 . As described above, the consumer group managed by the CEMS  20  (e.g., the consumer group  10 A and the consumer group  10 B) is, for example, a geographically divided consumer group or an apartment house, such as a condominium. Therefore, it is supposed that the equipments  11  provided in a consumer group managed by the same CEMS  20  are installed in similar installation environments (e.g., an average temperature or a building structure) even if the equipments  11  are managed by different EMSs  30 . Thus, the CEMS  20  calculates the second reference value using many measured values about the equipments installed in similar installation environments and of the same equipment type. Since the CEMS  20  uses the thus-calculated second reference value as the base at the time of determining an occurrence or a non-occurrence of an error of the equipment  11 , the CEMS  20  can determine an error of the equipment  11  accurately. 
       Second Modification 
       [0082]    Hereinafter, an equipment management system according to a second modification of the present embodiment will be described mainly with reference to differences from the equipment management system according to the first modification of the present embodiment.  FIG. 8  is a diagram illustrating a table stored in a storage  23  of the CEMS  20  according to the second modification. Since the configuration of the CEMS  20  according to the second modification is common to that of the CEMS  20  according to the first modification illustrated in  FIG. 5 , description thereof will be omitted. 
         [0083]    In the second modification, the controller  21  acquires operation conditions (e.g., heating, temperature a 1 , and an air volume b 1 ) of the equipment  11  in addition to the measured value about the equipment  11 . 
         [0084]    The storage  23  stores the measured value about the equipment  11  acquired by the controller  21 . In the second modification, the storage  23  stores the measured value about the equipment  11  for each equipment type and each operation condition of the equipment  11 . 
         [0085]    As illustrated in  FIG. 8 , the storage  23  includes a table that stores information about the equipment  11 . The storage  23  stores the equipment type and the operation conditions of the equipment  11 , and the second reference value in association with each other. 
         [0086]    In the second modification, the controller  21  calculates the second reference value for each of the operation conditions of a plurality of equipments. The storage  23  stores the second reference value about the equipment  11  in association with the equipment type and the operation condition of the equipment  11 . 
         [0087]    In the second modification, when a third measured value about the predetermined equipment is measured during an operation of the predetermined equipment according to predetermined operation conditions, the controller  21  determines an occurrence or a non-occurrence of an error of the predetermined equipment based on a comparison result between the third measured value about the predetermined equipment and the second reference value corresponding to the equipment type and the predetermined operation conditions of the predetermined equipment. 
         [0088]    As described above, in the equipment management system according to the second modification of the present embodiment, the CEMS  20  calculates the second reference value using the operation conditions in addition to the equipment type of the equipment  11 . Thus, the CEMS  20  calculates the second reference value in a manner more suitable to the usage status of the equipment  11 . Since the CEMS  20  uses the thus-calculated second reference value as the base at the time of determining an occurrence or a non-occurrence of an error of the equipment  11 , the CEMS  20  can determine an error of the equipment  11  accurately. 
       Third Modification 
       [0089]    Hereinafter, an equipment management system according to a third modification of the present embodiment will be described mainly with reference to differences from the equipment management system according to the second modification of the present embodiment.  FIG. 9  is a diagram illustrating a table stored in a storage  23  of the CEMS  20  according to the third modification. Since the configuration of the CEMS  20  according to the third modification is common to that of the CEMS according to the first modification illustrated in  FIG. 5 , description thereof will be omitted. 
         [0090]    In the third modification, the controller  21  acquires information about the equipment  11 . Information about the equipment  11  includes the equipment type and the installation environment (e.g., reinforced concrete construction) of the equipment  11 . 
         [0091]    In the third modification, the storage  23  stores the measured value about the equipment  11  for each equipment type, each operation condition, and each installation environment of the equipment  11 . 
         [0092]    As illustrated in  FIG. 9 , the storage  23  includes a table that stores information about the equipment  11 . The storage  23  stores the equipment type, the operation conditions and the installation environment of the equipment  11 , and the second reference value in association with each other. 
         [0093]    In the third modification, the controller  21  calculates the second reference value for each of the operation conditions and each installation environment of a plurality of equipments. The storage  23  stores the second reference value about the equipment  11  in association with the equipment type, the operation conditions, and the installation environment of the equipment  11 . 
         [0094]    In the third modification, the controller  21  determines an occurrence or a non-occurrence of an error of the predetermined equipment based on a comparison result between the third measured value about the predetermined equipment and the second reference value corresponding to the equipment type, the predetermined operation conditions and the predetermined installation environment of the predetermined equipment, when a third measured value about the predetermined equipment is measured during an operation of the predetermined equipment according to predetermined operation conditions and in a predetermined installation environment. 
         [0095]    As described above, in the equipment management system according to the third modification of the present embodiment, the CEMS  20  calculates the second reference value using the installation environment in addition to the equipment type and the operation conditions of the equipment  11 . Thus, the CEMS  20  calculates the second reference value in a manner more suitable to the usage status of the equipment  11 . Since the CEMS  20  uses the thus-calculated second reference value as the base at the time of determining an occurrence or a non-occurrence of an error of the equipment  11 , the CEMS  20  can determine an error of the equipment  11  accurately. 
       Other Embodiment 
       [0096]    Although the present invention has been described with reference to the embodiments described above, it should not be understood that the discussion and drawings constituting a part of the disclosure are limiting the present invention. Various alternative embodiments, examples and operation technology will be apparent to a person skilled in the art from the present disclosure. 
         [0097]    The EMS  30  may also be a home energy management system (HEMS), a store energy management system (SEMS), a building energy management system (BEMS), or a factory energy management system (FEMS). 
         [0098]    In the present embodiment, the EMS  30  calculates the first reference value using the measured value (and the operation conditions) about the equipment  11 . For example, in a case where the EMS  30  manages a plurality of equipments of the same equipment type, the EMS  30  may calculate the second reference value indicating the standard of the operation state for each equipment type and may determine an occurrence or a non-occurrence of an error of the equipment  11 . 
         [0099]    In the present embodiment, the CEMS  20  calculates the second reference value using the information, the measured values, and the like about the equipment  11 , and determines an occurrence or a non-occurrence of an error of the equipment  11 . Alternatively, the network server  40  may calculate the second reference value using the information, the measured values, and the like about the equipment  11 , and determine an occurrence or a non-occurrence of an error of the equipment  11 . 
         [0100]    Thus, it is a matter of course that the present invention includes a variety of embodiments or the like that are not described herein. Also, the foregoing embodiments and modification examples can be combined. Therefore, the technical scope of the present invention is defined only by specific matters of the invention according to the scope of the claim that is reasonable from the foregoing description. 
         [0101]    It is noted that the entire content of Japanese Patent Application No. 2013-014476 (filed on Jan. 29, 2013) is incorporated in the present specification by reference. 
       INDUSTRIAL APPLICABILITY 
       [0102]    According to the present invention, provided are the equipment management system, the equipment management apparatus, and the equipment management method capable of detecting the error of equipment accurately.