A) TECHNICAL FIELD

[0001] The present invention generally relates to Automated Meter Reading in power supply systems. The present invention particularly relates to power failure detection and notification system for sending Short Message Service (SMS) with a GSM network in absence of power supply. The present invention more particularly relates to power failure detection and notification system in energy meters for sending SMS to a central server in absence of supply using a super-capacitor.

B) BACKGROUND OF THE INVENTION

[0002] The traditional utility meter displays energy usage as an accumulation of counts presented to a display, which is used to calculate the monthly bill, it has applications within the electricity, gas and water utility industries for domestic, commercial and industrial applications. Sub metering is often used within a building, retail or industrial facility where it is desirable to measure power consumption for specific equipment, locations or sub-level accounts.

[0003] A conventional method for reading a utility (e.g., power, water, gas, etc.) meter is to send a meter-reading personnel of the utility company to a subscriber premises to record the meter reading and to compute meterage indicated at the meter. This method is susceptible to human error.

[0004] Thus, instead of the manual meter reading method, one solution to the problem is to automatically upload a meterage of the meter through a cable network. But this method preconditions that a dedicated line and a cable network should be installed in each subscriber's household nationwide. This can be very expensive.

[0005] A GSM type AMR, is the technology of automatically collecting consumption, diagnostic and status data from the Electronic energy metering devices and transferring that data for billing, troubleshooting and analyzing through GSM/GPRS network to a base central database.

[0006] The management software installed at the base central station will be able to establish connection with the remote site and data will be collected in auto dial mode or manual mode for analysis as and when required. During this time, the system at the base central station should have prior information that the modem at the meter end is in power ON condition or OFF condition. And accordingly it will schedule the scheduler (a software used to program the time of dialing the modems) to dial the modem and collect the data. Thus it can save the time and cost of unsuccessful dialing in case of switched OFF modems in the dialing list.

[0007] Automatic meter reading (AMR) is the technology of automatically collecting consumption, diagnostic and status data from water meter or energy metering devices (water, gas, electric) and transferring that data to a central database for billing, troubleshooting, and analyzing. This advance mainly saves utility providers the expense of periodic trips to each physical location to read a meter. Another advantage is billing can be based on near real time consumption rather than on estimates based on previous or predicted consumption. This timely information coupled with analysis, can help both utility providers and customers better control the use and production of electric energy, gas usage, or water consumption.

[0008] AMR technologies include handheld, mobile and network technologies based on telephony platforms (wired and wireless), radio frequency (RF) or power line transmission. In the event of a failure of the network due a natural disaster, sabotage, power failure or other network interruption, the Automatic meter reading (AMR) system is available in the disaster recovery plan as an alternative means of data collection to the fixed network.

[0009] A GSM/GPRS based AMR for Static energy meter will have a Base central station where their will a computer system with managed software and predefined GSM/GPRS modem which will be suitable for connection to the GSM/GPRS modem at meter end through GSM/GPRS network. And GSM modem at meter end will be connected to the Static energy meter with a suitable interface facility in the form of communication cord (optical/RS232) which will allow collecting data from meter.

[0010] The information of ON/OFF condition of the modem at meter end is very much important for the system at Base central station. So GSM modem at meter end should be capable of sending SMS as alert during Power failure and when power resumed with date and time. And also the AMR installed at the customer end may be manipulated such that AMR power supply will be removed accidentally or incidentally. Even in such cases, the GSM modem at meter end should send SMS which can help the administrator at the base central station to check the cause of power failure at the meter end.

[0011] Hence there is a need to provide a detection and notification system to detect the power failure condition in the AMR type energy meters and to notify the detected power failure condition to the central server through SMS effectively. Also there is a need for a notification system to communicate information of ON/OFF condition of the modem at meter end for the system at Base central station during power failure condition and also during the accidental or wanton removal of the AMR power supply is removed accidentally or incidentally, to enable the administrator at the base central station to check the cause of power failure at the meter end.

[0012] The above mentioned shortcomings, disadvantages and problems are addressed herein and which will be understood by reading and studying the following specification

C) OBJECT OF THE INVENTION

[0013] The primary object of the present invention is to develop a power failure detection and notification module to detect the mains failure and also to send a SMS to the predefined mobile number in the Modem In absence of the mains power.

[0014] Another object of the present invention is to develop a power failure detection and notification module to detect the mains failure and also to send a signal to the CPU of the MODEM to send SMS using Supercap backup to the predefined mobile number in the Modem in absence of mains power.

[0015] Yet another object of the present invention is to develop a Power ON detection and notification module to detect the mains power resumption and to send a signal to the CPU of the MODEM to send SMS using mains supply to the predefined mobile number stored in the MODEM,

[0016] Yet another object of the present invention is to develop a power failure detection and notification system to detect the tampering of the AMR/GSM Modem by the disconnection of Power supply to MODEM.

[0017] These and other objects and advantages of the present invention will become readily apparent from the following detailed description taken in conjunction with the accompanying drawings.

D) SUMMARY OF THE INVENTION

[0018] The various embodiments of the present invention provide a system and method for power failure detection and sending SMS to a central server in absence of supply using a super-capacitor power supply backup. According to one embodiment of the present invention, a power failure detection and notification system for energy meters has a switched mode power supply. A power failure detection circuit is connected to the switched mode power supply. A communication unit is connected to the switched mode power supply and the power failure detection circuit. A MOSFET switch is connected to the communication unit. Atleast one super capacitor is connected to the switched mode power supply and to the MOSFET switch.

[0019] The power failure detection circuit senses power failure to output an enable signal to MOSFET switch to supply the power from the super capacitor to the communication unit and to output a power interrupt signal to the communication unit to send a power failure notification.

[0020] The super capacitor is connected to the communication unit through the MOSFET switch to supply a backup power to the communication unit during the power failure period to send a power failure notification. The communication unit is connected to the MOSFET switch to output a disable signal to the MOSFET to turn off the MOSFET after sending a notification of power failure.

[0021] The MOSFET switch is turned off to cut the power supply from the super capacitor to the communication unit, when a notification of power failure is sent from the communication unit. The MOSFET Is supplied with the power from the switched mode power supply during the normal power supply period. The communication unit is powered with the electric power supplied from the switched mode power supply during the normal power supply period.

[0022] The system further comprises a current limiting resistor connected to the super capacitor. The super capacitor is charged with the power supplied from the switched mode power supply during the normal power supply period. The system further comprises a balancing resistor connected to the super capacitor to balance the power supplied from the super capacitors when pluralities of the super capacitors are connected to the system. The super capacitor supplies back up power for a preset period during the power failure period until a proper shut down operation is completed and a power failure notification is sent. The charge in the super capacitor is not drained completely during the power failure period. The communication unit is a modem. The communication unit sends a power failure notification through short message service.

[0023] According to one embodiment of the present invention, a power failure detection and notification system has a backup supply unit built with a super capacitor that is capable of supplying short term power supply to a system for a preset period of lime until a proper shutdown is completed and/or the main power is restored and/or a SMS is sent to a central database to notify that system is getting shutdown. Once the total system gets shutdown after sending SMS, the residual charge in the super-capacitor is still retained thereby requiring very less charge for charging back the super-capacitor during the next recharge cycle.

[0024] When the mains voltage goes below a cutoff level during power failures, a power detection circuit provided with an op-amp comparator circuit having a defined threshold voltage detects the power failure. The output of the comparator is used to switch ON the MOSFET switch (FDC6329L) which is having very low SWITCH ON drop at high current, to supply the required backup for the MODEM from a super capacitor to send SMS, The MOSFET switch is enabled to provide an uninterrupted power supply for the system. The super-capacitor is used to provide a fast acting short term power for the system during power failures. The super capacitors provide the power bursts needed for peak power events like SMS transmission and then get recharged when the main power is resumed,

[0025] When the Power is restored or switched ON again, the power detection circuit gives a signal to the MODEM to send SMS using a mains supply. During the supply of mains power, super-cap is charged with a constant current through a parallel tapping from SMPS secondary supply and the charge is stored in the super-cap. Only during power supply failures, the power from the super-cap is supplied to the Modem through a MOSFET switch after detecting the power failure. After a preset time (which is equal to time required to send SMS), MOSFET switch is disabled and hence the complete system is shutdown. This will ensure that the super-cap is not discharged completely thereby enhancing the life of super-cap.

[0026] Since the time required to send SMS by any GSM appliances after the power failure is very less (< 2 Sec), the designed circuit can supply the power continuously up to 10 consecutive power failures even without recharging the supercap. Since the supercap gets fully charged for one time and there is no complete discharging, the charging burden on SMPS secondary is very less.

E) BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The other objects, features and advantages will occur to those skilled in the art from the following description of the preferred embodiment and the accompanying drawings in which:

[0028] FIG. 1 illustrates a block circuit diagram of the power detection and notification system for energy meters according to one embodiment of the present invention.

[0029] FIG. 2 illustrates a flow chart explaining the MODEM operation in the power detection and notification system for energy meters according to one embodiment of the present invention.

[0030] Although specific features of the present invention are shown in some drawings and not in others. This is done for convenience only as each feature may be combined with any or all of the other features in accordance with the present invention.

F) DETAILED DESCRIPTION OF THE INVENTION

[0031] In the following detailed description, reference is made to the accompanying drawings that form a part hereof, and in which the specific embodiments that may be practiced is shown by way of illustration. These embodiments are described in sufficient detail to enable those skilled in the art to practice the embodiments and it is to be understood that the logical, mechanical and other changes may be made without departing from the scope of the embodiments. The following detailed description is therefore not to be taken in a limiting sense.

[0032] The various embodiments of the present invention provide a system and method for detecting power failure and sending SMS to a central server in absence of power supply using a super-capacitor power supply backup in an energy meter with AMR. Automating Meter Reading (AMR) which is a GSM / GPRS type connected to Static Energy meter for collecting data and storing into the server through GSM/GPRS network.

[0033] According to one embodiment of the present invention, a power failure detection and notification system for energy meters has a switched mode power supply. A power failure detection circuit is connected to the switched mode power supply. A communication unit is connected to the switched mode power supply and the power failure detection circuit. A MOSFET switch is connected to the communication unit. Atleast one super capacitor is connected to the switched mode power supply and to the MOSFET switch.

[0034] The power failure detection circuit senses power failure to output an enable signal to MOSFET switch to supply the power from the super capacitor to the communication unit and to output a power interrupt signal to the communication unit to send a power failure notification.

[0035] The super capacitor is connected to the communication unit through the MOSFET switch to supply a backup power to the communication unit during the power failure period to send a power failure notification. The communication unit is connected to the MOSFET switch to output a disable signal to the MOSFET to turn off the MOSFET after sending a notification of power failure.

[0036] The MOSFET switch is turned off to cut the power supply from the super capacitor to the communication unit, when a notification of power failure is sent from the communication unit. The MOSFET is supplied with the power from the switched mode power supply during the normal power supply period. The communication unit is powered with the electric power supplied from the switched mode power supply during the normal power supply period.

[0037] The system further comprises a current limiting resistor connected to the super capacitor. The super capacitor is charged with the power supplied from the switched mode power supply during the normal power supply period. The system further comprises a balancing resistor connected to the super capacitor to balance the power supplied from the super capacitors when pluralities of the super capacitors are connected to the system. The super capacitor supplies back up power for a preset period during the power failure period until a proper shut down operation is completed and a power failure notification is sent. The charge in the super capacitor is not drained completely during the power failure period. The communication unit is a modem. The communication unit sends a power failure notification through short message service.

[0038] According to one embodiment of the present invention, a power failure detection and notification system is provided to send SMS to a central server in absence of supply using a super-capacitor power supply backup. Electric double-layer capacitors, also known as super-capacitors, electrochemical double layer capacitors (EDLCs), or ultra-capacitors are an electrochemical energy storage device in the "power" industries. Compared with battery, super-capacitor has one-tenth of energy, but delivers over 10 times of power due to ultra low Equivalent Series Resistance (ESR). It operates more reliably in wider temperature and its life is semi-permanent, over 500,000 cycles.

[0039] The backup supply unit built with super capacitor is capable of supplying short term power to a system for a preset time until a proper shutdown is completed and/or the main power is restored and/or until a SMS is sent to a central database to notify that system is getting shutdown. Once the total system gets shutdown after sending SMS, the charge in the super-capacitor is still retained thereby consuming very less charge during the next recharge cycle.

[0040] FIG.1 illustrates the block diagram of the power detection and notification system for energy meters according to one embodiment of the present invention. The super cap 105 is capable of supplying short term power to a system for a set period of time until a proper shutdown is completed and/or the main power is restored and/or until a SMS is sent to a central database to notify that the system Is getting shutdown. Once the total system gets shutdown after sending the SMS, the charge in the super-capacitor 105 is still retained thereby consuming very less charge for recharging the super capacitor 105 during the next recharge cycle.

[0041] With respect to FIG.1, a power detection circuit 104 in which comparator circuit with a defined threshold voltage detects the power failure and the generates a power fail interrupt signal and enable signal during power supply failure period or when the mains voltage goes below a cutoff level. The power fail interrupt signal is output to the MODEM 108 to send SMS to the central server to notify the power failure. The enable signal is output from the detection circuit 104 is used to switch on the MOSFET 107 switch which is having very low switch on drop at high current to supply the required backup for the MODEM 108 from the super capacitor 105 to send a SMS to the central server to notify the power failure. After the sending of SMS, a disable signal is output to the MOSFET switch 107 from MODEM 108 to switch off the MOSFET switch 107, The MOSFET switch 107 is turned on to provide an uninterrupted supply for the system. Here the super cap 105 is used to provide fast acting short term power for the system during power failures. Super capacitors 105 provide the power bursts needed for peak power events like SMS transmission and then get recharge when main power is resumed. When the mains power is switched ON again, the power detection circuit 104 gives a signal to the MODEM 108 to send SMS. But the mains supply is used for sending SMS to the central server during this time.

[0042] During the supply of power from the mains, super-capacitor 105 is charged with a constant current through a current limiting resistor 109 from a parallel tapping of secondary supply of SMPS 101 and the charge is stored in the super cap 105. A balancing resistor 106 is used to control the voltage sharing across each super cap 105 when they are connected in series. Only during the power failures, power from the super-cap 105 is supplied to the Modem 108 through a MOSFET switch 107 after detecting the power failure. After the supply of power to the MODEM 108 for which is equal to time required to send SMS, the MOSFET switch 107 is disabled and hence the complete system gets shutdown. As a result, the super-cap 105 is not discharged completely thereby enhancing the life of super-cap 105.

[0043] Since the time require to send SMS by any GSM appliances after power failure is very less (< 2 Sec), the designed circuit is capable of supplying the power continuously for 10 consecutive power failure events even without recharging the super-cap 105. Since the super-cap 105 gets fully charged for one time and there is no complete discharging, the charging burden on the secondary of SMPS 101 is very less.

[0044] FIG. 2 illustrates a flow chart explaining the operation of a modem in the power detection and notification system for energy meters according to one embodiment of the present invention. During the mains power supply period, the super-cap is charged with a constant current through a current limiting resistor from a parallel tapping of SMPS secondary supply and the charge is stored in the super cap. An enable signal is output from the detection circuit to switch ON the MOSFET switch which is having very low switch ON drop at high current to supply the required backup power from the super capacitor to the MODEM to send SMS. A power failure interrupt signal is output to the MODEM from the detection circuit to send SMS to notify the power failure. Then a DISABLE signal is output from the MODEM after sending a SMS, to switch OFF the MOSFET switch. Only during the power supply failure period, the power from the super-cap is supplied to the MODEM through a MOSFET switch after detecting the power failure. After the supply of power to the MODEM from the super capacitor for a preset time which is equal to time required to send SMS, the MOSFET switch is disabled and hence the complete system gets shutdown. As a result, the super-cap is not discharged completely thereby enhancing the life of the super-cap.

[0045] The super-capacitor is used to provide fast acting short term power for the system during power failures. Super capacitors will provide the power bursts needed for peak power events like SMS transmission, and then get recharge when main power is resumed. When the Power is supplied again from the mains, the power detection circuit gives a signal to the MODEM to send SMS. But the power from the mains supply is used for sending SMS during this time.

G) ADVANTAGES OF THE INVENTION

[0046] Thus the various embodiments of the present invention provide a system and method for detecting power failure and sending SMS to a central server in absence of main power supply using a backup power supply with a super-capacitor. The system increases the life of the GSM/GPRS modem and also reduces the distortion while supplying the high peak power during the transmission of the SMS. The power bursts are needed for the peak power events like GSM/GPRS/ RF transmissions /SMS transmission. The system reduces the modem power consumption over long run compared to battery type of backup a super capacitor which is connected in parallel with SMPS secondary supply and charged with a constant current. The SMPS used in the modem does not get into Hiccup mode due to low Equivalent Series Resistance (ESR) of the super capacitor and totally avoids the abnormal start up of modem when the Mains Supply is restored. The super capacitor is charged with a constant current and discharged for very less time thereby enhancing the life of the GSM/GPRS modem design and improving the electrical safety to the users. The detection and notification circuit updates the server regarding the detection of power failure in mains power supply for more than 10 consecutive power failure events.

[0047] Although the invention is described with various specific embodiments, it will be obvious for a person skilled in the art to practice the invention with modifications. However, all such modifications are deemed to be within the scope of the claims.

[0048] It is also to be understood that the following claims are intended to cover all of the generic and specific features of the present invention described herein and all the statements of the scope of the invention which as a matter of language might be said to fall there between.

CLAIMS

What is claimed is:

1. A power failure detection and notification system for energy meters, comprising:

A switched mode power supply;

A power failure detection circuit connected to the switched mode power supply;

A communication unit connected to the switched mode power supply and the power failure detection circuit;

A MOSFET switch connected to the communication unit; and

Atleast one super capacitor connected to the switched mode power supply and to the MOSFET switch;

Wherein the power failure detection circuit senses power failure to output an enable signal to MOSFET switch to supply the power from the super capacitor to the communication unit and to output a power interrupt signal to the communication unit to send a power failure notification.

2. The system according to claim 1, wherein the super capacitor is connected to the communication unit through the MOSFET switch to supply a backup power to the communication unit during the power failure period to send a power failure notification.

3. The system according to claim 1, wherein the communication unit is connected to the MOSFET switch to output a disable signal to the MOSFET to turn off the MOSFET after sending a notification of power failure.

4. The system according to claim 1, wherein the MOSFET switch is turned off to cut the power supply from the super capacitor to the communication unit, when a notification of power failure is sent from the communication unit.

5. The system according to claim 1, wherein the MOSFET is supplied with the power from the switched mode power supply during the normal power supply period.

6. The system according to claim 1, wherein the communication unit is powered with the electric power supplied from the switched mode power supply during the normal power supply period.

7. The system according to claim further comprising a current limiting resistor connected to the super capacitor.

8. The system according to claim 1, wherein the super capacitor is charged with the power supplied from the switched mode power supply during the normal power supply period.

9. The system according to claim 1 further comprising a balancing resistor connected to the super capacitor.

10. The system according to claim 1, wherein the super capacitor supplies back up power for a preset period during the power failure period until a proper shut down operation is completed and a power failure notification is sent.

11. The system according to claim 1, wherein the charge In the super capacitor is not drained completely during the power failure period.

12. The system according to claim 1, wherein the communication unit is a modem.

13. The system according to claim 1, wherein the communication unit sends a power failure notification through short message service.