An electronic anti-disassembly system of an electric energy meter

Abstract

The utility model discloses a kind of electronic anti-disassembly systems of electric energy meter, system includes anti-disassembly sensor, main control module and relay drive circuit;Main control module is connected with anti-disassembly sensor, main control module and peripheral circuit, anti-disassembly sensor is used to detect electric energy meter uncovering action, relay drive circuit is connected with main control module and built-in relay.The utility model realizes anti-disassembly protection under complete power-off condition by energy storage capacitor and hardware latch circuit, and prevents the means of avoiding monitoring by power-off;Relay disconnecting action is triggered by pure hardware circuit, response speed is in microsecond to millisecond level, much faster than MCU software response speed, eliminates operation time window, using the memory function of hardware latch, illegal uncovering state can be recorded, until authorized reset, prevent malicious recovery.

Description

Technical Field

[0001] This utility model relates to the field of electricity meter technology, specifically an electronic anti-tampering system for electricity meters. Background Technology

[0002] As a key device for electricity measurement, the security and accuracy of data from electricity meters are of paramount importance. To prevent users from illegally opening the meter cover to steal electricity or tamper with the data, modern electricity meters are typically equipped with mechanical or electronic tamper protection devices. A common electronic tamper protection device is a microswitch or reed switch installed on the meter cover. When the cover is opened, the switch state changes, and the microcontroller (MCU) detects this change and records an opening event.

[0003] However, existing technologies have obvious drawbacks: Power outage avoidance: Electricity thieves may cut off the power supply to the electricity meter before opening the meter cover (e.g., by pulling down the user's circuit breaker). At this time, the MCU and detection circuit stop working due to power loss and cannot record the opening event. After power is restored, the system cannot detect the previously illegal opening behavior.

[0004] Response lag: Even without power interruption, after detecting an opening event, the MCU typically only logs the event and uploads data. Electricity thieves could exploit the brief time window between opening the cover and the MCU taking substantive action (such as disconnecting internal relays) for malicious purposes.

[0005] Therefore, there is an urgent need for an electronic anti-tamper system that can still function effectively in the event of a power outage and can quickly take hardware-level response measures. Utility Model Content

[0006] This utility model provides an electronic anti-tampering system for electricity meters, which aims to solve the problems mentioned in the background art.

[0007] To achieve the above objectives, this utility model provides the following technical solution: An electronic anti-tamper system for an electricity meter, the system includes a built-in relay and peripheral circuits, as well as an anti-tamper sensor, a main control module and a relay drive circuit; The main control module is connected to the anti-tamper sensor, the main control module, and peripheral circuits. The tamper-proof sensor is used to detect the opening action of the electricity meter cover; The relay drive circuit is connected to the main control module and the built-in relay. The relay drive circuit is used to control the opening and closing of the built-in relay according to the detection status of the anti-tamper sensor.

[0008] As a preferred technical solution of this application, the relay driving circuit includes a hardware latching unit, a driving unit, and a communication module; The hardware latch unit consists of an SR latch, which is connected to the tamper sensor; The driving unit is a transistor or MOSFET driving circuit, which is used to control the coil of the built-in relay. When the SR latch outputs a high level, the relay is disconnected; when the SR latch outputs a low level, the relay is energized. The communication module is used to communicate with the host computer system after an event occurs.

[0009] As a preferred technical solution of this application, the system also includes a power supply maintenance unit and a power supply circuit; The power supply maintenance unit consists of an energy storage capacitor, which is charged when the meter is supplying power normally and provides power to the subsequent logic circuit after the external power supply is disconnected. The power management circuit provides a stable operating voltage for the main control module and the energy storage capacitor.

[0010] As a preferred technical solution of this application, when the cover of the electricity meter is in the open state, the anti-tamper sensor contacts are disconnected and a high-level pulse signal is generated to the SR latch. When the cover of the electricity meter is closed, the anti-tamper sensor contacts close, generating a low-level pulse signal to the SR latch.

[0011] As a preferred technical solution of this application, the I / O port of the main control module detects the state change of the anti-tamper sensor, records the "opening event" in the program, and reports the event through the communication module.

[0012] This utility model achieves tamper protection under complete power failure by using energy storage capacitors and hardware latching circuits, thus eliminating the means of circumventing monitoring by power failure. The relay disconnection action is triggered by a purely hardware circuit, with a response speed in the microsecond to millisecond range, which is much faster than the MCU software response speed, thus eliminating the operation time window.

[0013] By utilizing the memory function of the hardware latch, the unauthorized opening state can be recorded until it is authorized to be reset, thus preventing malicious recovery. It can provide dual recording protection by combining hardware actions and MCU software recording to ensure reliable recording and reporting of events. Attached Figure Description

[0014] Figure 1 This is a framework diagram of an electronic anti-tamper system for electricity meters. Detailed Implementation

[0015] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0016] This utility model provides an electronic anti-tampering system for an electricity meter. The system includes a main control module, a built-in relay, and an external circuit. The external circuit is powered by an external AC power supply. It also includes an anti-tampering sensor, a main control module, and a relay drive circuit. The main control module is connected to the anti-tamper sensor, the main control module and peripheral circuits. The main control module is an MCU microcontroller, which is used to monitor the status of the anti-tamper sensor, control the on / off state of the relay, record events and upload data through the communication module. The tamper-proof sensor is used to detect the opening action of the electricity meter cover; The relay drive circuit is connected to the main control module and the built-in relay. The relay drive circuit is used to control the opening and closing of the built-in relay according to the detection status of the anti-tamper sensor.

[0017] In this embodiment, the relay driving circuit includes a hardware latch unit, a driving unit, and a communication module; The hardware latch unit consists of an SR latch, which is connected to the tamper sensor; The driving unit is a transistor or MOSFET driving circuit, which is used to control the coil of the built-in relay. When the SR latch outputs a high level, the relay is disconnected; when the SR latch outputs a low level, the relay is energized. The communication module is used to communicate with the host computer system after an event occurs. The host computer system is usually called an electricity metering automation system or an electricity information collection system. It is the core software platform that connects the underlying smart meters (terminals) with the upper-level management applications. It is existing technology and will not be described in detail here.

[0018] In this embodiment, the system also includes a power supply maintenance unit and a power management circuit; The power supply maintenance unit consists of an energy storage capacitor, which is charged when the meter is supplying power normally and provides power to the subsequent logic circuit after the external power supply is disconnected. The power management circuit provides a stable operating voltage for the main control module and the energy storage capacitor.

[0019] In this embodiment, when the cover of the energy meter is open, the anti-tamper sensor contact is disconnected and a high-level pulse signal is generated to the SR latch. When the cover of the electricity meter is closed, the anti-tamper sensor contacts close, generating a low-level pulse signal to the SR latch.

[0020] The main control module's I / O port detects changes in the status of the anti-tamper sensor, records "open cover events" in the program, and reports the events through the communication module.

[0021] The specific work steps are as follows: Normal state: The meter is powered normally, and the energy storage capacitor is fully charged. The tamper sensor is in the closed state, the S terminal of the hardware SR latch is at a low level, its output Q terminal is at a low level, the built-in relay drive circuit does not work, the relay remains energized, and the meter measures normally.

[0022] Opening event triggered (power supply normal): When the watch cover is opened, the tamper sensor contacts disconnect, generating a high-level pulse signal that is sent to the S terminal of the hardware latch.

[0023] When the SR latch is set, the output Q instantly flips to a high level and is latched to maintain that state.

[0024] The high level immediately drives the transistor / MOSFET to conduct, thereby de-energizing the built-in relay coil, causing the relay to quickly disconnect and cut off the metering circuit.

[0025] At the same time, the MCU's I / O port detects the change in the status of the anti-tamper sensor, immediately records the "open cover event" in the program, and reports the event through the communication module (such as carrier wave, low power wireless, RS485, etc.).

[0026] Opening event triggered (power disconnection): The electricity thief first disconnects the external power supply to the meter. At this point, the system is powered by the energy storage capacitor. The meter cover is opened, the anti-tamper sensor contacts disconnect, and a high-level pulse signal is sent to the S terminal of the SR latch. The SR latch is set, and the output terminal Q flips to a high level and latches the signal. This high level drives the drive transistor to conduct, and the built-in relay disconnects. The entire process is completed within milliseconds, powered by the energy storage capacitor, and completely independent of the MCU software flow, achieving a purely hardware-level rapid forced action.

[0027] The energy storage capacitor was subsequently depleted, and the system lost power completely, but the state of the latch was maintained due to its hardware characteristics.

[0028] After power is restored: External power to the meter was restored, and the system was powered back on.

[0029] After the MCU starts up, it first reads the current status of the anti-tamper sensor (disconnected) and the output status of the SR latch (high level). The MCU confirms that an opening event has occurred, records the event and uploads it.

[0030] The built-in relay remains open because the latch output is still high. Authorized personnel need to use specific instructions (such as a closing command issued by the host computer) to enable the MCU to control a reset signal (connected to the R terminal of the latch) to reset the latch and restore the relay to its active state. The above description is only a preferred embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any equivalent substitutions or changes made by those skilled in the art within the technical scope disclosed in the present utility model, based on the technical solution and the inventive concept of the present utility model, should be included within the protection scope of the present utility model.

Claims

1. An electronic anti-tamper system for electricity meters, comprising a built-in relay and external circuitry, characterized in that: It also includes tamper-proof sensors, a main control module, and relay drive circuitry; The main control module is connected to the anti-tamper sensor, the main control module, and peripheral circuits. The tamper-proof sensor is used to detect the opening action of the electricity meter cover; The relay drive circuit is connected to the main control module and the built-in relay. The relay drive circuit is used to control the opening and closing of the built-in relay according to the detection status of the anti-tamper sensor.

2. The electronic anti-tamper system for an electricity meter according to claim 1, characterized in that: The relay drive circuit includes a hardware latch unit, a drive unit, and a communication module; The hardware latch unit consists of an SR latch, which is connected to the tamper sensor; The driving unit is a transistor or MOSFET driving circuit, which is used to control the coil of the built-in relay. When the SR latch outputs a high level, the relay is disconnected; when the SR latch outputs a low level, the relay is energized. The communication module is used to communicate with the host computer system after an event occurs.

3. The electronic anti-tamper system for an electricity meter according to claim 1, characterized in that: The system also includes a power supply maintenance unit and power supply circuitry; The power supply maintenance unit consists of an energy storage capacitor, which is charged when the meter is supplying power normally and provides power to the subsequent logic circuit after the external power supply is disconnected. The power management circuit provides a stable operating voltage for the main control module and the energy storage capacitor.

4. The electronic anti-tamper system for an electricity meter according to claim 1, characterized in that: When the cover of the energy meter is open, the anti-tamper sensor contacts are disconnected and a high-level pulse signal is generated to the SR latch. When the cover of the electricity meter is closed, the anti-tamper sensor contacts close, generating a low-level pulse signal to the SR latch.

5. The electronic anti-tamper system for an electricity meter according to claim 1, characterized in that: The main control module's I / O port detects changes in the tamper sensor's status, records "open cover events" in the program, and reports the events through the communication module.

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