] The present invention relates to a device and a method to log metering and ambient data from a power meter, more specifically, a device to independently log data from within a power meter.
BACKGROUND OF THE INVENTION
[002] Electricity meters, power meters, or electric energy meters are installed in homes and businesses to register the energy consumed by the customers. During the life of an electricity meter, its main function of registering energy might get defeated due to tamper attempts or malfunctioning of meter itself. This results in a loss of revenue for the utilities, as in such cases there is no trace of data available, which could be used for preparing a bill or producing a theft case in the court of law. Further, in the event of a fire or an electrical accident, a conventional memory housed inside the electricity meter is likely to be damaged or could become malfunction by heat or electrically damage.
[003] Hence, there is a need to safeguard utilities from their lost revenue if the meter malfunctions or is tampered with, by being able to independently log data from a power meter.
SUMMARY OF THE INVENTION
[004] According to an embodiment, the present invention discloses a device to independently log data from a power meter. The device includes a metering data recording unit configured to record a metering data from the power meter. The metering data recording unit is connected to a meter circuitry. The device includes a clock unit configured to time stamp the metering data to generate timestamped metering data. The device also includes a memory unit configured to store the timestamped metering data.

[005] According to an embodiment, the present invention discloses a method for monitoring a power meter. The method includes recording a metering data registered by the power meter at a periodic interval. The method also includes time stamping the metering data to generate a timestamped metering data and sensing at least one of an ambient parameter or an operational parameter. The method further includes storing the timestamped metering data in a memory.
BRIEF DESCRIPTION OF THE DRAWINGS
[006] The foregoing and other features of embodiments of the present invention will become more apparent from the following detailed description of embodiments when read in conjunction with the accompanying drawings. In the drawings, like reference numerals refer to like elements.
[007] Fig 1 illustrates a conceptual diagram of a device to independently log data from a power meter, in accordance with an embodiment of the invention.
[008] Fig 2 illustrates a schematic view of the device to independently log data from a power meter, in accordance with an embodiment of the invention.
[009] Fig 3 illustrates an input/output (io) data protection circuit, in accordance with an embodiment of the invention.
[010] Fig 4 illustrates an electrical protection for a power line, in accordance with an embodiment of the invention.
[011] Fig 5 illustrates a flow chart of a method for monitoring a power meter, in accordance with an embodiment of the invention.
DETAILED DESCRIPTION
[012] In the following detailed description, reference is made to the accompanying drawings that form a part hereof, and in which shown by way of illustration specific embodiments that may be practiced. These embodiments are described in sufficient detail to enable a person skilled in the art to practice the

invention, and it is to be understood that other embodiments may be utilized and that logical, mechanical, and other changes may be made within the scope of the embodiments. Also, the words "comprising," "having," "containing," and "including," and other similar forms 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. The singular forms "a," "an," and "the" include plural references unless the context clearly dictates otherwise. The following detailed description is, therefore, not be taken as limiting the scope of the invention, but instead the invention is to be defined by the appended claims.
[013] The present invention discloses a device and a method to log metering and ambient data from a power meter. According to an embodiment, the present invention discloses a device to independently log data from within a power meter. The device includes a metering data recording unit configured to record a metering data from the power meter, wherein the metering data recording unit is connected directly to a meter circuitry. The device includes a clock unit configured to time stamp the metering data to generate timestamped metering data. The device also includes a memory unit configured to store the timestamped metering data.
[014] Fig 1 illustrates a conceptual diagram of a device (100) to independently log a data from a power meter, in accordance with an embodiment of the invention. The device (100) is configured to independently log data from a power meter (104). The device (100) includes a metering data recording unit (102) configured to record metering data from the power meter (104), wherein the metering data recording unit (102) is connected to a meter circuitry (not disclosed in the diagram). The device (100) includes a clock unit (106) configured to time stamp the metering data with real time to generate a timestamped metering data. The device (100) also includes a memory unit (108) configured to store the timestamped metering data.
[015] In an embodiment of the present invention, the clock unit (106) employed for stamping the data captured with real time is designed to work independent from

the real time clock of the power meter. Typically, the power meter (104) also includes a real time clock, where as the clock unit (106) is independent of the working of the real time clock of the power meter (104).
[016] In an embodiment of the present invention, the device (100) is configured to independently log data from within a power meter. In an embodiment of the present invention, the metering data recording unit (102) is connected directly to the meter circuitry. In yet another embodiment of the present invention, the metering data recording unit (102) is connected through another device that records the data from the meter circuitry. In an embodiment of the present invention, another device may be a data recorder that is part of the power meter (104).
[017] According to another embodiment of the present invention, the device (100) includes a sensor unit to sense at least one of an ambient parameter or an operational parameter. According to another embodiment of the present invention, the device (100) includes a processing unit configured to process the timestamped metering data and the at least one of the ambient parameter or the operational parameter to identify an anomaly. In an embodiment of the present invention, the processing unit is in a cloud server. In yet another embodiment of the present invention the processing unit is in an external processor. According to an embodiment of the present invention, the anomalies identified includes, but not limited to an abnormal change in energy parameters, main processor not responding, abnormal ambient readings from sensors.
[018] In an embodiment of the present invention, the device (100) includes at least one processor to receive an input and to provide appropriate output for the various units of the device (100) such as metering data recording unit, clock unit, memory unit, sensor unit, processing unit. In an embodiment of the present invention, the processor runs at a low clock speed. In an embodiment of the present invention, the processor is a microprocessor. In yet another embodiment of the present invention, the processor is a micro controller. In another embodiment of

the present invention, the device (100) includes a communication unit configured to provide a communication interface between various units of the device (100).
[019] In an embodiment of the present invention, the low clock speed is the speed at which the curve in the phase space between the time required and the energy required (integral of Pdt) to perform the task is at the minimum. In other words, the power (which is linearly related to clock speed with a fixed bias term) has to be low, but the execution time should also be small enough so that the energy is also very low. This depends on the specifics of the microcontroller selected. Typically, the clock speed is low enough to optimize the time required and the total energy required including the full operational mode and the interim waiting mode.
[020] According to an embodiment of the present invention, the device (100) operates with an external power source. According to another embodiment of the present invention, the device (100) includes a backup battery configured to provide backup power to the device (100). In an embodiment of the present invention, when the external power source fails then the device (100) utilizes the backup battery to continuously log data from the power meter. The backup battery makes sure that the device works even during the external power source failure or main power supply failure. In an embodiment of the present invention, the external power source is the main power supply to the power meter. In an embodiment of the present invention, the backup battery is a super capacitor.
[021] According to another embodiment of the present invention, the device (100) is housed within a shielding with an air gap to bypass an external electrical noise and a radio frequency noise. In an embodiment of the present invention, the shielding is either a single or a multilayer conductive cubical metal. In an embodiment of the present invention, the shielding is suitably and solidly grounded, to bypass the external electrical noise and the radio frequency noise. In an embodiment of the present invention, the device (100) is connected to the power meter through at least one power rail with transient and surge protection, wherein the transient protection filters designed to slow any change in voltage or current

due to an induced transient. In an embodiment of the present invention, the transient and surge protection is by using passive filters and transient voltage suppressor. In yet another embodiment of the present invention, the device (100) is connected to the power meter through a data line to log the data from the power meter. Typically, the data line is to transmit data communications between power meter and the device. In an embodiment of the present invention, the data line is protected against transients and surges using passive filters and transient voltage suppressor. In another embodiment of the present invention, the data line is protected against transients and surges using optical coupling. In an embodiment of the present invention, an input drive and /or an output drive strength is decreased to increase the rise and fall times. In an embodiment of the present invention, the decreased strength of input drive and/or an output drive helps to reduce high frequency components in the transition. In yet another embodiment of the present invention, a low bit rate is used for communication between the power meter and the device (100). Typically, the communication between the power meter and the device (100) is the range of 600 to 1200 bits per second (bps).
[022] In an embodiment of the present invention, the sensor unit includes a temperature sensor to detect the ambient temperature. In another embodiment of the present invention, the sensor unit includes a radio frequency (RF) sensor and a magnetic field sensor that are kept outside the shielding. The radio frequency sensor senses the external radio frequency influence, whereas the magnetic field sensor senses the strong influencing magnetic fields. In yet another embodiment of the present invention the sensor unit includes a humidity sensor to detect a fluid ingress. In yet another embodiment of the present invention, the sensor unit includes an accelerometer. The accelerometer is used to measure the jerks and mechanical shocks to the device (100).
[023] In an embodiment of the present invention, the device (100) is compact such that the surface area of the device (100) is designed to be as small as possible. In an embodiment of the present invention, typically the size of the device is 1.25 inch by 1.25 inches.

[024] According to an embodiment of the present invention, the device (100) is designed to be immune to all influencing disturbances such as but not limited to electromagnetic interference (EMI), electrostatic discharge (ESD), high frequency injection at levels much higher than the meter could withstand using the shielding, power line and data line protections and other structural features of the device.
[025] According to another embodiment of the present invention, the device is placed in an under belly of the power meter, so that a main board of the power meter acts as the shielding for the device. In another embodiment of the present invention, sharp corners are avoided to reduce potential build-up on the device.
[026] According to another embodiment of the present invention, the power meter (104) is at least one of a smart meter or a conventional power meter.
[027] In an embodiment of the present invention, the device (100) is embedded inside a power meter so that it is not visible to the common users.
[028] Fig 2 illustrates a schematic view of the device to independently log data from a power meter, in accordance with an embodiment of the invention. The device (200) is connected to a main supply (202) through a multiplexer (power max) (204) a power converter. A backup battery (206) is connected to power max (204) to provide backup power to the device (200). The device (200) includes the processor (208) which is having the metering data recording unit (not shown in the figure) to independently log the data from a main processor (300) in the power meter (not shown in the figure). The main processor (300) is connected to the processor (208) through a data line (302) with an input protection circuit and/or an output protection circuit (304). A power line (306) from the main power supply (202) is connected to the device (200) to provide a supply power to the device (200) through the multiplexer (204). The power line (306) is provided with an electric protection circuit (400). The processor (208) is connected to a real time clock (RTC) (210) configured to time stamp the metering data to generate time stamped metering data. The time stamped metering data is stored in a non-volatile memory (NVM) (212). The device (200) includes a temperature sensor (214) coupled to a

sensor unit (not shown in the figure) to sense the ambient temperature. The device (200) includes an accelerometer sensor (216) coupled to a sensor unit (not shown in the figure) to record peak shocks, jerks, and movement during the operation of the device that are utilized for diagnosis and help in recreation of an event. The device (200) includes other sensors (218) coupled to the sensor unit to sense other ambient parameter and operational parameter. Typically, in an embodiment other sensors include sensors such as but not limited to a radio frequency (RF) sensor, a magnetic field sensor for breach detection (case open detection), cellular signal strength sensor, humidity sensor etc. The device (200) includes a metal shielding that protects device against EMI/EMC radiations. The device (200) includes a serial port (220) to retrieve data through the processor (208) for further processing. Typically, the data is retrieved after failure of the main power meter typically in a laboratory setup. The device (200) includes a power-on reset (222) that generates a reset impulse that goes to the device to reset into a known state. The processor (208) is configured to send an interrupt through a data line (310) to the main processor (300). The data line (310) through which the interrupt is send has a data protection (not shown in the figure) similar to the data protection (304). The device (200) is provided with a shielding (not shown in the figure) to protect the data stored in the non-volatile memory (212) from tampering. The data is stored in the non-volatile memory (212) in an encrypted format.
[029] Fig 3 illustrates the input/output (io) data protection circuit (304), in accordance with an embodiment of the invention. As shown in the example embodiment of Fig 3, the input/output data protection circuit (304) is a passive filter and transient voltage suppressor. The data from the main microprocessor (Main MCU) (350) is an input to the transient voltage suppressor. The transient voltage suppressor includes two diodes, wherein the first diode (340) is connected to a voltage source and a second diode (342) t is grounded. The transient voltage suppressor diodes clamp transient voltages (eg: ESD events) to a safe level before they can damage a circuit. In an embodiment of the present invention, the transient voltage suppressor diodes uses at least one of a standard diode or Zener diode. In

yet another embodiment of the present invention, the transient voltage suppressor is a transient-voltage-suppression (TVS) diode. The passive filter includes a resistor (344) in series to a capacitor (346). The capacitor (346) is grounded. The output (348) from the passive filter is given to the device. In an embodiment of the present invention, the passive filter passive is used to suppress harmonic currents and decrease voltage distortion appearing in sensitive parts of the device.
[030] Fig 4 illustrates an electrical protection circuit for a power line in accordance with an embodiment of the invention. The electrical protection circuit (400) is a passive filter and transient voltage suppressor. The supply from the main supply (412) is input to the transient voltage suppressor. The transient voltage suppressor includes two diodes, wherein the first diode (402) is connected to a voltage source Vcc and a second diode (404) is grounded. The transient voltage suppressor diodes clamp transient voltages (eg: ESD events) to a safe level before they can damage a circuit. In an embodiment of the present invention, the transient voltage suppressor uses at least one of a standard diode or Zener diode. In yet another embodiment of the present invention, the transient voltage suppressor is a transient-voltage-suppression (TVS) diode. The passive filter includes two capacitors (406 and 408) connected parallel, which is in series with an inductor (410). The capacitators (406 and 408) are grounded properly. The output (414) from the passive filter is given to the device.
[031] Fig 5 illustrates the flow chart of a method for monitoring a power meter, in accordance with an embodiment of the invention. The method (500) includes the step (502) of recording a metering data registered by the power meter at a periodic interval. The method (500) includes the step (504) of time stamping the metering data to generate a time stamped metering data. The method (500) also includes the step (506) of sensing at least one of an ambient parameter or an operational parameter. The method (500) includes the step (508) of storing the timestamped metering data and at least one of the ambient parameter or the operational parameter in a memory.

[032] In an embodiment of the present invention, the periodic interval may be typically one hour such that the device records the metering data from the power meter typically in every one hour. In another embodiment of the present invention, a user can program the device and set the periodic interval. In another embodiment of the present invention, when the memory gets utilized completely the device starts rewriting the memory from the beginning on a first-in-first-out basis.
[033] In an embodiment of the present invention, the step (506) of sensing at least one of the ambient parameter or the operational parameter helps to measure the jerks and mechanical shocks occurred to the device using the respective sensors. In another embodiment of the present invention, the step (506) of sensing at least one of the ambient parameter or the operational parameter detects strong influencing magnetic fields using external magnetic field sensors. In yet another embodiment of the present invention, the step (506) of sensing at least one of the ambient parameter or the operational parameter detects external radio frequency influence using radio frequency sensors. In yet another embodiment of the present invention, the step (506) of sensing at least one of the ambient parameter or the operational parameter detects fluid an ingress using humidity sensor. In an embodiment of the present invention, the step (506) of sensing at least one of the ambient parameter or the operational parameter includes sensing the operational parameter such as metering parameters such as energies, tamper status word etc.
[034] In an embodiment of the present invention, the method (500) includes the step of processing the time stamped metering data and at least one of the ambient parameter or the operational parameter to identify an anomaly. In an embodiment of the present invention, the anomalies include but not limited to abnormal changes to energy parameters, main processor not responding, abnormal ambient readings from the sensors. In yet another embodiment of the present invention, the step of processing utilizes a multivariate Gaussian estimation to determine an outlier in order to identify the anomaly.

[035] In yet another embodiment of the present invention, the method (500) includes the step of rebooting a metering micro of the power meter when the anomaly indicates of a stoppage of function of the power meter.
[036] In another embodiment of the present invention, the method (500) further includes the step (504) of time stamping the metering data and the step (508) of storing the timestamped metering data. In one embodiment of the present invention, the time stamping of the metering data and the storing of the timestamped metering data may be independent of a function or a malfunction of the power meter. Typically, the functioning or malfunctioning of the power meter doesn't interrupt the performance of step of time stamping the metering data and the step (506) of sensing at least one of the ambient parameter or the operational parameter which helps the method to identify the anomaly even when the power meter malfunctions.
[037] In yet another embodiment of the present invention, the method (500) includes the step of retrieving the time stamped metering data and at least one of the ambient parameter or the operational parameter (herein after referred as data) in a secure setting. In an embodiment of the present invention, the data is stored in an encrypted form to prevent the unauthorized access of the data. The shielding of the device provides further protection for data from tampering.
[038] The present invention in accordance with an embodiment keeps an independent record of the energy registered by the power meter typically for each hour for a period of say last 'n' months, where n is the number of months for which the record of the energy is stored. The method and device in accordance with an embodiment of the invention helps to reproduce the data recorded by the device as evidence in the court of law in the event of a dispute or while prosecuting the meter tampering accused. The present invention further helps to helps in investigation of the root cause of the malfunction of the power meter. The method and device in accordance with another embodiment of the invention works as a supervisor wherein it reboots the main metering micro in case it hangs and stops metering due

to tampering or malfunction. In another embodiment of the present invention, the device in accordance with the present invention is immune to all influencing disturbances such as electromagnetic interference (EMI), electrostatic discharge (ESD) at levels much higher than the power meter could withstand. In yet another embodiment of the present invention, the device helps to keep an independent record of energy registered by the power meter and is designed to be immune to all influencing disturbances.
[039] The foregoing description of the preferred embodiment of the present invention has been presented for the purpose of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed. Furthermore, all examples recited herein are principally intended expressly to be only for pedagogical purposes to aid the reader in understanding the principles of the present subject matter and are to be construed as being without limitation to such specifically recited examples and conditions. Many modifications and variations are possible in light of the above teachings.

We claim:

1) A device to independently log data from a power meter, wherein the device
comprises:
- a metering data recording unit configured to record a metering data from the power meter, wherein the metering data recording unit is connected to a meter circuitry;
- a clock unit configured to time stamp the metering data to generate a timestamped metering data; and
- a memory unit configured to store the timestamped metering data.

2) The device as claimed in claim 1, further comprises a sensor unit to sense at least one of an ambient parameter or an operational parameter.
3) The device as claimed in claim 2, further comprises a processing unit configured to process the time stamped metering data and the at least one of the ambient parameter or the operational parameter to identify an anomaly.
4) The device as claimed in claim 1, further comprises a backup battery configured to provide backup power to the device.
5) The device as claimed in claim 1, wherein the device is housed within a shielding with an air gap to bypass an external electrical, radio frequency noise or combination thereof.
6) The device as claimed in claim 1, wherein the power meter is at least one of a smart meter or a conventional power meter.
7) The device as claimed in claim 1, wherein the device is within the power meter.
8) A method for monitoring a power meter, wherein the method comprising:

- recording a metering data registered by the power meter at a periodic interval;
- time stamping the metering data to generate a timestamped metering data;
- sensing at least one of an ambient parameter or an operational parameter; and
- storing the timestamped metering data and at least one of the ambient parameter or the operational parameter in a memory.

9) The method as in claim 8, further comprising processing the time stamped metering data and at least one of the ambient parameter or the operational parameter to identify an anomaly.
10) The method as in claim 9, further comprising rebooting a metering micro of the power meter when the anomaly indicates of a stoppage of function of the power meter.
11) The method as in claim 8, wherein time stamping the metering data and storing the timestamped metering data is performed independent of a function or a malfunction of the power meter.
12) The method as in claim 8 comprising retrieving the time stamped metering data and at least one of the ambient parameter or the operational parameter in a secure setting.