A SYSTEM AND METHOD FOR MANAGING SUBSTATION
Field of the Invention
The present invention generally relates to power distribution systems. More particularly, the present invention relates to Smart Substation Management System (SSMS) which is an automation of distribution substation so as to remotely monitor and manage the substation in a power distribution network.
Background of the Invention
To cater to ever increasing power demand, power distribution companies need to look at capacity augmentation and optimization of their power distribution networks to eliminate bottlenecks. In power distribution system, SMART grid promises a more efficient way of supplying and consuming energy, wherein the SMART implies Self-Monitoring, Analysis and Reporting Technology. In essence, the smart grid is a data communications network integrated with the power grid that enables power grid operators to collect and analyze data about power generation, transmission, distribution, and consumption—all in near real time. Smart grid communication technology provides predictive information and recommendations to utilities, their suppliers, and their customers on how best to manage power.
To achieve the above, there is a need in the art to bring more automation and intelligence to the power grid network to address a myriad of utility concerns such as how to reduce operational expenses and at the same time meeting new regulatory requirements. This may help to ensure a secure smart grid and a reliable and sustainable energy supply in power distribution system.
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Object(s) of the Invention:
The principal object of the present invention is to provide a system, method and apparatus for managing at least one substation in a power distribution network.
Another object of the invention is to provide a better energy accounting for loss measurement in the power distribution network.
Yet another object of the invention is to improve uptime of equipment in the power distribution network.
Further object of the invention is to improve the consumer satisfaction by quick detection of faults and its removal in the power distribution network.
Furthermore object of the invention is to reduce the cost of asset management in the power distribution network.
Another object of the invention is to generate MIS reports for informed decision making based on meter data.
Summary of the Invention:
Before the system, method, apparatus and hardware enablement of the present invention are described, it is to be understood that this invention in not limited to the particular systems, and methodologies described, as there can be multiple possible embodiments of the present invention which are not expressly illustrated in the present disclosure. It is also to be understood that the terminology used in the description is for the purpose of describing the particular versions or embodiments only, and is not intended to limit the scope of the present invention which will be limited only by the appended claims.
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The present invention provides a system and apparatus for managing at least one substation in a power distribution network.
According to one embodiment of the invention, a substation management system including: at least one first unit coupled to a first sensor unit and configured to receive a first set of parameters from at least one transformer, at least one second unit coupled to a second sensor unit and configured to receive a second set of parameters from at least one substation, a third unit operatively coupled to the at least one first and second unit and configured to receive and process the first and second set of parameters, and at least one server operatively coupled to the third unit and configured to receive and analyze the processed first and second set of parameters and initiate necessary actions when there is any abnormality identified in value or status of one or more of the processed first and second set of parameters.
According to another embodiment of the invention, the third unit is further coupled to at least one energy meter and configured to receive meter data or parameters.
According one exemplary embodiment of the invention, the at least one first unit comprises Distribution Transformer (DT) unit, the at least one second unit comprises Ring Main (RM) unit and the third unit comprises Field Remote Terminal Unit (FRTU).
According to another exemplary embodiment of the invention, the first set of parameters comprises oil temperature, oil level, and/or terminal temperature, and the second set of parameters comprises isolator/breaker status, fault passage indicator status, and/or door status.
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According to another embodiment of the invention, the abnormality is identified when the value or status of the processed first and second set of parameters go above or below a predetermined value or change one state to other. Upon identifying the abnormality, the server sends alarm/alert to the concerned authority level via communication medium such as Short Message Services (SMS), and/or electronic email (email).
According to yet another embodiment of the invention, a system for monitoring at least one substation comprising: a first server having a database, wherein the database comprises values and status of plurality of parameters related to at least one first unit, at least one second unit, and at least one energy meter located in the at least one substation; and a second server having a graphical user interface, the second server operatively coupled to the first server and configured to monitor performance of the at least one substation by accessing the value or status of the one or more of the plurality of parameters.
According to another embodiment of the invention, the second server further configured to generate a report based on one or more of the plurality of parameters.
According to another embodiment of the invention, the second server further configured to initiate necessary actions if there is any abnormality identified in value or status of one or more said parameters.
According to one exemplary embodiment of the invention, the at least one first unit comprises Distribution Transformer (DT) unit, the at least one second unit comprises Ring Main (RM) unit and the third unit comprises Field Remote Terminal Unit (FRTU).
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According to further another embodiment of the invention, a method for managing at least one substation comprising: receiving a first set of parameters by at least one first unit from at least one transformer; receiving a second set of parameters by at least one second unit from the at least one substation; processing the first and second set of parameters by a third unit and sending the processed parameters to at least one server; analyzing the processed first and second set of parameters; and initiating necessary actions when there is any abnormality in value or status of one or more of first and second set of parameters is identified.
According to another embodiment of the invention, identifying the abnormality comprises determining when the value or status of one or more of the first and second set of parameters go above or below a predetermined value or change one state to other.
Brief description of the drawings:
The foregoing summary, as well as the following detailed description of preferred embodiments, is better understood when read in conjunction with the appended drawings. For the purpose of illustrating the invention, there is shown in the drawings example constructions of the invention; however, the invention is not limited to the specific systems, methods and apparatus disclosed in the drawings: Figure 1 represents an exemplary block diagram of an overview of a system according to an embodiment of the present invention.
Figure 2 depicts a flow diagram of a method according to an embodiment of the present invention.
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Figure 3 depicts a block diagram of an apparatus according to an embodiment of the present invention.
Detailed description of the invention:
Some embodiments of this invention, illustrating its features, will now be discussed in detail. The words "comprising," "having," "containing," and "comprising," and other forms thereof, are intended to be equivalent in meaning and be open ended in that an item or items following any one of these words is not meant to be an exhaustive listing of such item or items, or meant to be limited to only the listed item or items. It must also be noted that as used herein and in the appended claims, the singular forms "a," "an," and "the" comprise plural references unless the context clearly dictates otherwise. Although any systems, methods and apparatuses similar or equivalent to those described herein can be used in the practice or testing of embodiments of the present invention, the preferred, systems, methods and apparatuses are now described. The disclosed embodiments are merely exemplary of the invention, which may be embodied in various forms by a person skilled in the art.
System of the present invention is a key component towards SMART Grid. The system allows predictive maintenance prior to the fault by giving indication. Its function comprises condition monitoring of various assets such as transformer and switchgear along with intrusion detection, fire detection, energy meter management, reactive power management through active power factor correction (APFC), Fault detection and isolation in the network within less than an hour. The system/method/apparatus of the present invention may be designed and developed to work at 11KV/415V distribution substation level.
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Figure 1 represents an exemplary block diagram of an overview of a system according to an embodiment of the present invention. In one exemplary embodiment of the invention, a substation management system (100) includes a Distribution Transformer (DT) unit (106), Ring Main (RM) unit (112), Field Remote Terminal Unit (FRTU) (108), Server Unit (116) and Client terminal unit (118). The DT unit (106), RM unit (112), FRTU (108) may be referred as first unit, second unit, and third unit respectively.
In accordance with one aspect of the invention, DT unit (106) may be installed at a site consisting of Distribution Transformers, wherein the distribution transformer is a transformer that provides the final voltage transformation in the electric power distribution system, stepping down the voltage used in the distribution lines to the level used by the customer. If mounted on a utility pole, they are called pole-mount transformers. If the distribution lines are located at ground level or underground, distribution transformers are mounted on concrete pads and locked in steel cases, thus known as pad mount transformers.
In one aspect of the invention, the DT unit (106) may be coupled with FRTU (108) via coupling means and configured to manage the substation in the power distribution network, wherein the coupling means may be RS 485 standard connection. In a preferred embodiment of the invention, 4 no’s of DT unit s (106) may be connected with the FRTU (108). Alternatively, number of DT units (106) may be increased more than 4 based on the requirements.
In another aspect of the invention, the DT unit (106) comprises at least one microcontroller unit, at least one analog-digital convert unit, at least one operational amplifier circuit unit, and at least one connection port unit. In yet another aspect of the invention, the DT unit (106) also includes a first sensor unit (104), wherein the first sensor unit (104) installed outside the DT unit (106). In both cases, the first sensor unit (104) communicatively coupled to the
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DT unit (106) and configured to receive a first set of parameters from the transformer. In one exemplary embodiment of the invention, the first set of parameters may be oil temperature, oil level, and terminal temperature.
In a preferred embodiment of the invention, the microcontroller unit of DT unit (106) may be ARM 32 bit Microcontroller. The DT unit (106) may additionally comprise at least one External Flash Memory, RS485 Communication, NO/NC Contacts.
In one exemplary embodiment of the invention, the first sensor unit (104) may comprise various sensors like Door sensor, fire sensor, LT palm temperature sensor, Gas sensor, Oil level sensor, oil temperature sensor which may be mounted on transformer and switchgear. These sensors may send the first set of parameters using analog and digital signals to DT unit (106). In one aspect, the FRTU (108) may directly receive the above parameters directly from the first sensor unit (104).
In another exemplary embodiment of the invention, the sensor may be a device that measures a physical quantity and converts it into a signal which can be read by an instrument. The sensors may comprise a top mounted oil level sensor, wherein the sensor may be used to measure level of oil in the Transformer. In case the level of oil Decrease below the limit it will sense and generate the alarm indicating requirement for the maintenance. The sensors may comprise a Top mounted oil temperature sensor, wherein the sensor may be used to sense the temperature of oil. It may offer excellent accuracy over wide range of transformer from (-200°C to 850°C). The sensors may comprise a Door sensor, wherein the sensor may Open Contact Switch (N/O) for Closed Loop System (N/C). The sensors may comprise a Fire and smoke sensor, wherein the sensor may be a plug in fire detector combining optical smoke Detection, heat detection and microprocessor control with Analog Addressable
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Communications. The sensors may comprise a LT palm temperature sensor, wherein the sensor may be used to measure the interface temperature at output 3-Ph RYB feeders from the transformer. This sensor may be sandwiched between the cable and the transformer terminal. This sensor may be thermocouple based and measure temperature up to 200°C with an accuracy of 0.5°C.
In a preferred embodiment of the invention, DT unit (106) may be an electronic printed circuit board used as a distributed input /output unit. It may be mounted on DT or near to DT collecting various distribution transformers parameter as listed below. This PCB may be mounted in a PVC box suitable for outdoor application.
In one exemplary embodiment of the invention, the lists of sensors may be connected to DT units (106) are palm temperature, oil temperature, oil level, fire/smoke detector, door sensor (open/close) and DT Unit RS485 Connection.
In a preferred embodiment of the invention, the DT unit (106) may sense the parameters pertaining to the transformers such as the R, Y, B Phase temperature, ambient temperature, oil level. It also detects the Fire and intrusion. It may be interfaced with the FRTU (108) and communicates all the data when demanded by the FRTU (108).
In another aspect of the invention, the DT unit (106) may take analog input from 5 PT100 sensors (R, Y, B, N, oil Temperature) and digital inputs from oil level sensor, door sensor, and/or fire sensor. DT unit data may be periodically sent to FRTU (108) through RS‐485 communication on receiving required command from FRTU (108) which is a half-duplex communication. The DT unit (106) may send alarm data to FRTU (108) instantaneously on occurrence of any alarm event.
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In another aspect of the invention, the DT unit (106) may be a subsystem which is housed at the distribution transformers with a 32 bit ARM Microcontroller sensing the parameters pertaining to the distribution transformer such as the Oil temp, R-Phase-Phase-Phase and/or N-phase Temperature. The DT unit (106) has the provision of sensing the digital input to sense the status of NO/NC contacts for oil level, door and fire sensors which are optically isolated via opto couplers. The DT unit (106) may communicate all the sensor and digital data to the FRTU board via RS485 Communication interface.
In a preferred embodiment of the invention, the communication between the DT unit (106) and FRTU (108) may be based on RS‐485 half duplex communication, wherein the FRTU (108) acts as master and send unique command for each DT Unit (106) and wait for required response. Each DT Unit (106) has its unique address. The command Sent by FRTU (108) is received by all DT units (106). Only Single DT Unit (106) responds which address has matched with command sent by FRTU (108).
Initially all DT units (106) may be configured as receiver for RS‐485 communication and FRTU (10) may be configured as transmitter for RS‐485 communication. FRTU (108) may send the required command to DT units (106) and change its mode to receiver waiting for response from DT units (106). DT units (106), after receiving the required commands, may change its mode to transmitter and may send the data and then change its mode to receiver. This procedure repeats itself whenever data from DT units (106) is to be taken.
In accordance with one aspect of the invention, the RM unit (112) may be installed at Ring Main Unit, where Ring Main Unit is standard piece of
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switchgear in distribution systems comprising of switches for switching power cable rings and of switches in series with fuses for the protection of distribution transformers. RM unit (112) used for H.T. side. RM unit (112) is having 3no’s of switches (Circuit Breakers or Isolators or LBS), it may be used for two inputs with mechanical or electrical interlock and one outgoing to the load. Either one input with two outgoings. RM unit (112) may be used for redundancy feeder's purpose.
In a preferred embodiment of the invention, the RM unit (112) may be coupled with FRTU (108) via coupling means and configured to manage the substation in the power distribution network, wherein the coupling means may be RS 485 standard connection.
In accordance with another aspect of the invention, the RM unit (112) may comprise at least one microcontroller unit and at least one connection port unit. In a preferred embodiment of the invention, the RM unit (112) also comprises a second sensor unit (110), wherein the second sensor unit (110) can be either embedded in the RM unit (112) or installed outside the RM unit (112). In both cases, the second sensor unit (110) communicatively coupled to the DT unit (106) and configured to receive a second set of parameters from at least one substation in the distribution network.
In a preferred embodiment of the invention, the microcontroller unit of RM unit (112) may be ARM 32 bit Microcontroller. The RM unit (112) additionally comprises at least one external flash memory, RTC battery, digital inputs, digital outputs, and analog inputs.
In one exemplary embodiment of the invention, the second sensor unit (110) may comprise various sensors like open/close status of breaker and isolator
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switch of RM unit (112), gas pressure switch of RM unit (112), breaker trip status of RM unit (112), and/or fault passage indicator status on incoming line.
In another exemplary embodiment of the invention, the sensors (110) may comprise a gas sensor, wherein the sensor may be used to sense pressure in circuit breaker. The sensors may comprise an isolator and circuit breaker status sensor, wherein the sensor may be used to sense open or close position of isolator and circuit breaker. The Fault Passage Indicator (FPI) may comprise at least one circuit breaker and at least one grid feeder. When a fault occurs between section x & y it is detected with the help of core balance current transformer (CBCT) installed at substation S1 & S2 which operates alarm contacts for remote indication and illuminates an integral LED at substation S1 & S2 while indicator at Substation S3 will not glow thus indicating faulty section of the network. The FPI indicator may help in pin pointing faulty section between two substations thus eliminating the need to check every section between two substation starting from grid. The FPI status may also be used in a graphical user interface of the client unit for monitoring the health of the substation.
In one exemplary embodiment of the invention, 90%-95% of the total fault in the network occurs because of earth fault. When a fault occurs between section x & y it is detected with the help of CBCT installed at substation S1 & S2 which operates alarm contacts for remote indication and illuminates an integral LED at substation S1 & S2 while indicator at Substation S3 will not glow thus indicating faulty section of the network. Maintenance engineer will check LED illuminating at different substation from the grid as soon as the substation is reached where LED is Off indicates fault between the last illuminating LED substation and Off LED substation section. The FPI indicator may help in pin
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pointing faulty section between two substations thus eliminating need to check every section between two substation starting from grid.
In another exemplary embodiment of the invention, an Integration of FPI and Geographical Information System (GIS) may be used to locate the fault in the network. When a fault occurs between any section instead of checking every substation it is easy to track glowing FPI in GIS and directly locate the fault in the network. When faults occur in the network engineer can keep a track of network through GIS system. Illuminating LED’s represent that particular feeder is faulty; Red LED’s may represent Substations after the faulty section in particular areas which may be referred as A1, A1, A2, A3, etc. In this way it locate the fault and maintenance engineer will work directly in the faulty section at site in this way help in saving time and quick fault removal.
In another exemplary embodiment of the invention, the second set of parameters may be isolator/breaker status, fault passage indicator (FPI) status, and/or door status. In a preferred embodiment of the invention, RM unit (112) may be an electronic printed circuit board used as an input/output unit. It may be mounted on RM Unit (112) or near to RM Unit (112). This unit collecting RM unit (112) switch status and FPI status. This PCB may be mounted in a PVC Box suitable for outdoor application. There are two parts of the RM unit (112), one is the control board and other is the termination board.
In another aspect of the invention, the RM unit (112) may be used in a secondary distribution system. It is basically used for an uninterrupted power supply. Alongside, it also protects the secondary side transformer from the occasional transient currents. Depending on the applications and loading conditions a switch fuse combination or a circuit breaker may be used to protect the transformer. This transformer connected to the switch fuse/circuit breaker is called Toff. In a common arrangement, load break switches on both the sides of
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the Toff. The RM units (112) come in standard ratings of 11/22/33 kV, 630/1250 A, 21 KA/3 secs.
The RMU connector board may take input from CBCT, isolator, three fault passage indicators, and/or circuit breakers and transmit it to the main RM unit (112) board via 50pin connector. The RM unit board further communicates it to the FRTU (108) board via RS485 communication and produces control output at the relay. It also takes input from the door sensor.
In a preferred embodiment of the invention, the RM unit data may periodically send to FRTU (108) through RS‐485 communication on receiving required command from FRTU (108). It is half duplex communication. In another embodiment of the invention, the communication between the RM unit (112) and FRTU (108) is based on RS‐485 half duplex communication. The FRTU (108) act as master and send command for RM Unit (112) and wait for required response.
Initially RM unit (112) is configured as receiver for RS‐485 communication and FRTU (108) will be configured as Transmitter for RS‐485 communication. FRTU (108) sends the required command to RM unit (112) and change its mode to receiver waiting for response from RM unit (112). The RM unit (112) after receiving the required commands changes its mode to transmitter and sends the data and then changes its mode to receiver. This Procedure repeats itself whenever data from RM unit (112) is to be taken.
In accordance with one aspect of the invention, the FRTU (108) may be the central unit which may be installed at the remote place. The FRTU (108) coupled to DT unit (106) and RM unit (112) and configured to receive and process the first and second set of parameters.
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In one exemplary embodiment of the invention, the FRTU (108) may comprise at least one microcontroller unit, at least one memory unit, at least one GPRS communication unit, and at least one connection port unit. In a preferred embodiment of the invention, the microcontroller unit of FRTU (108) may be ARM 32 bit Microcontroller. The FRTU (108) additionally comprises at least one 16x2 alphanumeric LCD, RTC Battery, Lithium ion Battery Backup, RS232 Communication, RS485 Communication and NO/NC Contacts.
In one aspect of the invention, the system also comprises at least one meter/energy meter unit (102) and server unit (116). Alternatively, more than one meter units (102) may be coupled with the FRTU (108) and configured to send metered data to the FRTU (108). In a preferred embodiment of the invention, the meter unit (102) may be coupled with the FRTU (108) via RS 232 standard connection. The server unit (116) may be coupled to the FRTU (108) and configured to acquire at least one parameter from at least one DT unit (106), RM unit (112) and/or the FRTU (108) and send it to the client terminal unit (118). In one exemplary embodiment of the invention, the server unit (116) may comprise at least one server and the client terminal unit (118) may comprise at least one computing device such as computer, laptop, and/or mobile, etc. In accordance with another aspect of the invention, the server unit (116) may be located inside or outside the substation. The end user can set the parameters for generating the alarm in the DT unit (106), RM unit (112), and/or FRTU (108) using the graphical user interface of the client terminal unit (118).
These alarms may set by the end user according to priority levels as critical and normal. By way of non-limiting example, they may set as:
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In a preferred embodiment of the invention, the server unit (116) may be connected with the FRTU (108) via communication unit (114) such as wired connection or wireless connection such as internet, and the server unit (116) may be connected with the client terminal unit (118) via at least one communication means such as wired connections or wireless connection such as internet. In one exemplary embodiment of the invention, the communication unit (114) may include communication network. The communication network may follow GSM or GPRS mode of communication. The communication unit (114) may be either embedded inside the FRTU (108) or installed outside the FRTU (108). The server unit (116) and the client terminal unit (118) may be located at the site and/or remote place.
In another aspect of the invention, DG set APFC unit may also be connected with the FRTU (108) via communication means, wherein the communication means may be RS 485 standard connection. The DG set APFC unit may be
S.No
ALARMS
CRITICAL
NORMAL
RESPONSE TIME
1
Fire

1 hrs
2
Door open

4 hrs
3
Oil Temperature

24 hrs
4
Oil Level

36 hrs
5
Terminal Temperature

24 hrs
6
FPI

NA
7
RMU Gas

NA
8
Isolator Status
NA
NA
NA
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located at the site and configure to save energy consistently maintain high power factor in the DT unit (106) using FRTU (108).
In one aspect of the invention, the FRTU (108) acquires all parameters from the sensors and meter units (102) and transmits the desired information to the remote server unit (116) through on board GSM/GPRS Modem. All sensor data may be communicated to the FRTU (108) through RS485 Communication. FRTU (108) has digital input to sense the status of NO/NC contacts which are optically isolated via opto couplers and outputs to control the units in the field. FRTU (108) also has RS-232 and RS-485 communication interface available on the unit to communicate with Energy meters (102) and RM Units (112), DT units (106) respectively.
In another aspect of the invention, the FRTU (108) may be the master unit that has on board GSM/GPRS modem that sends data to logging server (116) via TCP/IP communication. FRTU (108) may be interfaced with DT unit (106), RM unit (112) through RS‐485 half duplex interface and Energy Meter (102) through RS‐232 interface.
In another exemplary aspect of the invention, the FRTU (108) may be connected to maximum three energy meter (102), six door sensors, two fire sensors, three DT units (106) and one RM unit (112). The model which may be used upon in the system is DATA PULL model that is whatever command it gets from the server, the desired result is produced and provided to the server. All data is sent to the server through GSM/GPRS communication. FRTU (108) has internal flash memory M25P32 (4MB) to store configuration parameters and to store sensor thresholds. These values can be remotely configurable through SMS or Web interface.
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In another exemplary aspect of the invention, the FRTU (108) has quad band GSM/GPRS modem on board to communicate with the remote server unit (116). GSM/GPRS modem works on standard AT commands and establishes TCP/IP communication with remote server to transfer periodic data and alarms as and when they arrive.
Energy Meter data (Instantaneous parameters, Load survey, Events) are taken using secure meter API program in TCP/IP mode which will run on remote data logging server. Energy Meter data may be used to determine loading, unloading of transformer, polarity.
In accordance with one aspect of the invention, the meter unit (102) may be configured to produce instantaneous parameters, load profile, energy/demand, tamper, and/or events.
In one exemplary aspect of the invention, the metered data may comprise line current, voltage and power factor will be sent in cyclic mode to central server (116) in time interval of 30 minutes. Metered data may be analyzed as per validation rules in case of abnormality SMS and e-mail on lotus note will be sent to DT maintenance engineer to check the DT meter within 48 hours. It also helps in improving time involved in DT metering. It also may store three months live data and rest will be archived in the data disc.
The metered data may also comprise the parameters of unbalancing the transformer and loading the transformer. The unbalancing of the transformer may be identified as follows:
When 5% and above value of the total current flowing through RYB phase start flowing through neutral refers to unbalancing and this unbalancing can be detected with the help of system.
The loading of the transformer may be identified as follows:
Loading can be of two types overloading and under loading:
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When the transformer is loaded above its threshold value it is called overloading and transformer loaded below its optimum value is called under loading.
By way of non-limiting example, 1MVA transformer has maximum loading limit of 120% whereas the optimum value for the same exist as 70% loading. So for any loading above 120% will be detected by the system (100) is termed as overloading and below 70% is termed as under loading.
Transformer loading can be detected with the help of system (100).
In a preferred embodiment of the invention, the FRTU (108) may be communicated with the meter unit (102) based on RS‐232 communication protocol. Four Energy Meters (102) may be interfaced with FRTU (108) and at a time data may be taken from any one Energy meter (102) which is selected by multiplexer in FRTU (108).
Data may be acquired through two methods either by giving direct command to meter by FRTU (108) which will give corresponding Instantaneous Parameters value or by using Server side API which will give Load profile, Energy/Demand, Tamper, Events.
Acquiring the Energy Meter Instantaneous Parameters may comprise:
First command will be given to FRTU (108) from server (116). FRTU (108) responds with the serial number of meter connected;
Server (116) may check the validity of meter’s serial number received. Valid Serial number should be of length 10 and it should contain SP in first two places;
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After validating serial number of meter, data is taken from corresponding meter (102) whose serial number is valid by giving corresponding command;
If command is valid then sent it to FRTU (108);
After giving command, server (116) may wait for 120 seconds for response from FRTU (108);
At a time only one meter reading command may be given and after waiting for 120 seconds for response from FRTU (108), another meter reading command can be issued depending on validity of serial number; and
All the parameters values received may be stored in the memory of FRTU (108).
Energy Meter Data through API may be taken by configuring FRTU (108) in transparent mode. Server (116) may initiate the API on scheduled basis and accordingly FRTU (108) may configure itself in transparent mode. In this mode, commands received from server (116) are sending to meter (102) and responses from meter (102) are sending to server (116). At a time only one meter (102) may be read through API which is selected by multiplexer in FRTU (108). On successful reading of meter (102) by API transparent mode is disabled and MRD file is formed at server (116). The meter reading conforms to Minimum Interoperability Standard (MIOS) standard.
Acquiring the Energy Meter data/parameters through API may comprise:
First command will be given to FRTU (108) from server (116). Then FRTU (108) responds with the serial no of meter connected;
Then Server (116) checks the validity of meter’s serial number received. Valid Serial No should be of length 10 and it should contain SP in first two places;
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After validating serial no of meter data is taken from corresponding meter whose serial no is valid by giving corresponding command;
If the command is valid then sent it to FRTU (108), this command indicates FRTU (108) that meter data should be taken from first meter and then FRTU (108) will open first meter port by configuring multiplexer accordingly and configure itself in transparent connection mode;
FRTU will open the corresponding port on receiving the command;
After each meter reading command server (116) will initiate API and meter is read using API which runs at server (116);
At a time only one meter reading command is given and after the API times out either by successful reading or unsuccessful reading another meter reading will be issued depending on validity of serial no;
On successful reading of meter by API MRD file will be formed at server (116); and
Meter reading through API is scheduled one in a day.
In one embodiment, server communication protocol may define the set of commands and responses from server (116) and FRTU (108) for acquiring data in system from different devices which comprises DT Unit (106), RM unit (112) and Energy Meter (102). This communication protocol may be based on data pull architecture where FRTU (108) sends the data when it receives required command from Server unit (116). Server unit (116) may have full control on FRTU (108) connected at sites where it can take schedule data from FRTU (108).
In one exemplary aspect of the invention, the FRTU (108) may communicate with the server (116) by initiating a request and receiving the verified acknowledgement from the server (116).
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In the Request Initiation, the server may be in listening mode waiting for FRTU (108) to connect at fixed IP and port number which is stored on the FRTU (108). Whenever FRTU (108) wants to establish connection with server (116) it first establishes TCP/IP socket with server (116) at predefined port at predefined public IP address. It sends IMEI (15 Digit unique no for each Device) to server (116). After the initiation, the server (116) waits for valid IMEI no. When a valid IMEI number is received it acknowledges the FRTU (108), wherein the valid IMEI number should have length of 15.
In one exemplary aspect of the invention, the server (116) may be scheduled to take DT unit (106), FRTU (108), RM unit (112) parameters and Energy Meter Instantaneous Parameters every 15 minutes on alternate basis. These parameters may be stored and updated in a database unit. Data may comprise DT unit (106), RM unit (112), FRTU (108) parameters, Energy Meter Instantaneous Parameters, Energy Meter Load Profile, Energy, and Events.
In one exemplary embodiment of the invention, the parameters may comprise oil temperature, oil level, R, Y, B, N phase line temperature, fire alarm, door/intrusion alarm, FPI alarm through CBCT, isolator/breaker potential free contacts, meter frequency, meter currents on R, Y, B line, meter voltages of R, Y, B line, and/or power factor of R, Y, B line and average power factor.
In another aspect of the invention, the server operatively coupled to the FRTU (108) and configured to receive and analyze the processed first and second set of parameters and initiate necessary actions when there is any abnormality identified in value or status of processed first and second set of parameters. The abnormality is identified when the value or status of the one or more of processed first and second set of parameters go above or below a predetermined value or change one state to other.
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In one exemplary aspect of the invention, the necessary actions may be include sending the Short Message Service (SMS) and/or Electronic mail (Email) to the concerned authority levels by the server (116), wherein the SMS and/or email will be generated according to criticality of data.
The server (116) may perform the confirmation for resolving the fault in every one hour by cross‐checking the updated data from the Main Data Base. If fault is not resolved then a SMS along with mail may be generated and it sends starting from lower authority level to higher authority level. In every hour, they are sent to higher authority level to the previous authority level. This process may be repeated until the fault is not resolved.
In another exemplary embodiment of the invention, the server (116) may receive the parameters directly from DT unit (106), RM Unit (112), and/or energy meter (102).
In another exemplary embodiment of the invention, the FRTU (108) may be configured to perform the above function when the abnormalities identified. In another exemplary embodiment, the various units or components or sub components of the system (100) may be connected to each other in a suitable manner or alone and configured to achieve the objects of the present invention.
Figure 2 depicts a flow diagram of a method (200) according to an embodiment of the present invention. At 202, a first set of parameters is received by the DT unit (106) from at least one transformer. The DT unit (106) may receive these parameters periodically upon receiving request from the FRTU (108), or without any such request (i.e. on its own), from the first sensor unit (104). These parameters may be received at a client/user device (118) as and when required by a user to monitor the performance of the one or substations.
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At 204, a second set of parameters is received by the RM unit (112) from the at least one substation. These parameters may be different from the first set of parameters. These parameters may be received from the second sensor unit (110). The RM unit (112) may receive these parameters periodically upon receiving request from the FRTU (108), or without any such request (i.e. on its own), from the first sensor unit (104). These parameters may be received at the client/user device (118) as and when required by a user to monitor the performance of the one or substations.
At 206, the received first and second sets of parameters are processed by the FRTU (108). In one aspect, the FRTU (108) may analyze these parameters to identify the abnormality in value or status of any one of these parameters. The FRTU (108) may compare the received parameters value or status with stored threshold value or status of these parameters and identify the abnormality. In another aspect, the FRTU (108) may send a notification to an authorized person to correct the abnormality. In one aspect, the FRTU (108) may receive these parameters upon receiving a request from the server unit (116). The FRTU (108) may process these received parameters to the server unit (116) for analyzing, in one aspect.
At 208 and 210, the server unit (116) may analyze these parameters and send a notification to the authorized person if there is any abnormality is identified in the value or status of the analyzed parameters. The notification may be an e-mail or short message service (SMS), or any other suitable communication. In this process, the server unit (116) may compare the analyzed parameters value or status with the stored parameters value or status. The server unit (116) may also store the value or status of these parameters periodically in a database unit. The sever unit (116) may update these parameters periodically in the database unit. The database unit may be located inside the server unit (116) or outside
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the server unit (116). These stored values may be accessed by the authorized person for any predictive maintenance of the substation.
Figure 3 depicts a block diagram of an apparatus according to an embodiment of the present invention. The apparatus (300) may comprise a data acquisition system module (302), an alarm management module (306), a network management module (308), a transformer data management module (304), and a user management module (310). The data acquisition system module (302) may access the data or parameters from the database unit of the server unit (116) whenever it is required. The data acquisition system module (302) may collect the meter data or parameters, transformer parameters and switchgear status, FPI action status, alarms and outage notifications. The data acquisition system module (302) may also collect other parameters as described above. The data acquisition system module (302) may also configure sensor threshold for different substations. The sensor threshold may be used for analyzing the sensed parameters. The transformer data management module (304) may analyze one or more of the parameters as collected by the data acquisition system module (302). The transformer management module (304) may compare the one or more collected parameters with the threshold or predetermined value or status as stored in the data acquisition system module (302). The transformer management module (304) may responsible for analyzing meter and transformer sensor data/parameters. The transformer management module (304) may also allow user or the apparatus to derive DT health report from the basic metered and/or analyzed parameters.
Based on meter data the transformer management module (304) will be able to generate various MIS reports like current unbalancing, power factor, reactive energy for informed decision making.
By way of non-limiting example, the report may comprise as below:
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The report may be generated on daily basis considering the abnormal sensor parameters which may comprise information about oil temperature, oil level, fire, door, motion sensor and palm temperature of distribution transformers. In this, a report may be generated considering single parameter one at a time for all the concerned authority levels. The report may be generated hierarchy wise. In one aspect, the report may be generated on daily basis which may comprise information about overloading and the unbalancing of distribution transformer. The overloading report may consist of overloading range based on the overall capacity of the distribution transformers such as 0-20%, 20%-40%, 40%-60%, 60%-80%, and 80%-100%. The unbalancing report may consist of how much the DT was unbalanced for the entire day in percentage. The report may be delivered to the concerned authority personnel such as substation, sub-division, division, circle and CEO. The DT health may be monitored by analyzing the transformer data/parameters, meter data/parameters, RMU data/parameters and GIS.
Transformer data may contain following transformer parameters:
Oil Level -Normal, low and very low. Normal oil level requires no
action. For low and very low oil level alarm automatic alarm may be generated;
Ambient Temperature‐ It may give an idea about oil temperature. Oil
temperature may be predicted on the basis of ambient temperature;
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Oil Temperature‐When the oil temperature exceeds 85°C an automatic
alarm may be generated;
R phase palm temperature- when the R phase palm temperature exceeds
85°C an automatic alarm may be generated;
Y phase palm temperature‐ when the Y phase palm temperature exceeds
85°C an automatic alarm may be generated;
B phase palm temperature‐ when the B phase palm temperature exceeds
85°C an automatic alarm may be generated;
N phase palm temperature ‐when the N phase palm temperature exceeds
85°C an automatic alarm may be generated;
Door‐ If the door of the substation or transformer is open an automatic
alarm may be generated. When the door is closed it requires no action;
Smoke sensor‐ when smoke is detected by the smoke sensor an
automatic alarm may be generated;
Alarms‐ Users may acknowledge the alarms to log an event; and
Events‐ It may show in a table the Transformer data for which an alarm
is acknowledged along with its status and event date and time.
The alarm management module (306) may generate alarms when there is any abnormality identified in the value or status of one or more of the analyzed parameters. The alarm management module (306) may compare the one or more collected parameters with the threshold or predetermined value or status to identify the abnormality, in one aspect. The alarm management module (306) may send a notification to an authorized person to correct abnormality upon identification. The user or the apparatus may also define threshold for different alarms along with their priorities using the alarm management module (306). Also, SMS and email notification details of user may be configured using the alarm management module (306). The user management module (310) may create and manage users with different privilege level, along with their other
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details (post, location, contact number, email, etc.). It may also allow administration to keep track record of different activity taken up by employees. The network management module (308) may manage the geographic, administrative, regional and electrical hierarchy of the complete system or substation. It may comprise GIS based mapping of the different Zones, Circle, Division, Subdivision, Substation, Feeder, Transformers etc. The network management module (308) may manage the relation between different hierarchies and allows easy navigation for users. The modules as described above may be operatively connected to each other in any suitable manner to perform the desired functions as described above.
The steps of a method described in connection with the embodiments disclosed herein may be interchanged, and not all steps need to be reached. The steps of a method described in connection with the embodiments disclosed herein may be embodied directly in hardware, in a software module executed by a processor, or in a combination of the two. A software module may reside in non-transitory memory, such as RAM memory, flash memory, ROM memory, EPROM memory, EEPROM memory, registers, hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art, comprising semiconductor, optical, and/or magnetic storage mediums, comprising computer-readable storage mediums. An exemplary storage medium is coupled to the processor such the processor can read information from, and write information to, the storage medium. In the alternative, the storage medium may be integral to the processor. The processor and the storage medium may reside in an ASIC. The ASIC may reside in a user terminal. In the alternative, the processor and the storage medium may reside as discrete components in a user terminal.
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Those of skill would appreciate that the various illustrative logical blocks, components, and modules and method steps described in connection with the embodiments disclosed herein may be implemented as electronic hardware, computer software, or combinations of both. To clearly illustrate this interchangeability of hardware and software, various illustrative components, blocks, modules, and steps have been described above generally in terms of their functionality. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the overall system. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present invention.
The various illustrative logical blocks, components, and modules described in connection with the embodiments disclosed herein may be implemented or performed with a general purpose processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general purpose processor may be a microprocessor, but in the alternative, the processor may be any conventional processor, controller, microcontroller, or state machine. A processor may also be implemented as a combination of computing devices, e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration.
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Advantages of the Invention:
The system, method and apparatus of the proposed invention may be used for
 Real Time Monitoring of Transformer Health (Oil Level, Oil Temp, Palm Temp, Fire Indicator, Door Status).
 Acquisition of Instantaneous Parameters, Load Survey, Energy, Tamper, Events of Energy Meter.
 Automatic Alarm generation on user defined parameters and information through SMS and email.
 Tracking of action taken by responsible person and automatic Escalation of Alarms on inaction by responsible person to higher authority.
 Real Time Monitoring of RMU (Ring Main unit) Switching parameters (Isolator, Breaker, FPI, CBCT) and SF6 Gas Pressure.
 Seamless Integration with GIS (Geographic Information Systems).

We Claim:
1. A substation management system comprising:
at least one first unit coupled to a first sensor unit and configured to receive a first set of parameters from at least one transformer;
at least one second unit coupled to a second sensor unit and configured to receive a second set of parameters from at least one substation;
a third unit operatively coupled to the at least one first and send units and configured to receive and process the first and second set of parameters; and
at least one server operatively coupled to the third unit and configured to receive and analyze the processed first and second set of parameters and initiate necessary actions when there is any abnormality identified in value or status of one or more of processed first and second set of parameters.
2. The system as claimed in claim 1, wherein the first set of parameters comprises oil temperature, oil level, and/or terminal temperature.
3. The system as claimed in claim 1, wherein the second set of parameters comprises isolator/breaker status, fault passage indicator status, and/or door status.
4. The system as claimed in claim 1, wherein the abnormality is identified when the value or status of the one or more of processed first and second set of parameters go above or below a predetermined value or change one state to other.
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5. The system as claimed in claim 1, wherein the third unit is further coupled to at least one energy meter and configured to receive meter data or parameters.
6. The system as claimed in claim 1, wherein the at least one first unit comprises Distribution Transformer (DT) unit, the at least one second unit comprises Ring Main (RM) unit and the third unit comprises Field Remote Terminal Unit (FRTU).
7. A method for managing at least one substation comprising:
receiving a first set of parameters by at least one first unit from at least one transformer;
receiving a second set of parameters by at least one second unit from the at least one substation;
processing the first and second set of parameters by a third unit and sending the processed parameters to at least one server;
analyzing the processed first and second set of parameters; and
initiating necessary actions when there is any abnormality in value or status of one or more of the first and second set of parameters is identified.
8. The method as claimed in claim 7, wherein receiving the first and second set of parameters comprises receiving a request related to the said parameters from the third unit.
9. The method as claimed in claim 7, wherein processing the first and second set of parameters comprises receiving a request related to the said parameters from the at least one server.
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10. The method as claimed in claim 7, wherein identifying the abnormality comprises identifying when the value or status of one or more of the first and second set of parameters go above or below a predetermined value or change one state to other.
11. Apparatus for monitoring at least one substation, comprising:
a data acquisition module for collecting plurality of parameters related to at least one first unit, at least one second unit, and at least one energy meter located in the at least one substation;
a transformer data management module for analyzing one or more of the plurality of parameters; and
an alarm management module for generating alarm when there is any abnormality identified in the one or more of the analyzed parameters.
12. The apparatus as claimed in claim 11, wherein the plurality of parameters comprises oil temperature, oil level, terminal temperature, isolator/breaker status, fault passage indicator status, and/or door status.
13. The apparatus as claimed in claim 11, wherein the at least one first unit comprises Distribution Transformer (DT) unit, and the at least one second unit comprises Ring Main (RM) Unit.
14. The apparatus as claimed in claim 11, wherein the transformer data management module further configured to generate a report based on one or more of the analyzed parameters.