Intelligent cost control electric energy meter

Abstract

The utility model relates to the technical field of electric energy meters, in particular to an intelligent cost control electric energy meter, which comprises a resistance voltage division voltage detection circuit, a resistance type current sampling circuit, a digital-to-analog conversion module, a metering chip, a microprocessor, a memory and a meter calibration pulse module, the output ends of the resistance voltage division voltage detection circuit and the resistance type circuit sampling circuit are electrically connected with the digital-to-analog conversion module respectively, the digital-to-analog conversion module is electrically connected with the input end of the metering chip, and the metering chip is electrically connected with the meter calibration pulse module; the output end of the metering chip is electrically connected with the microprocessor, and the microprocessor is electrically connected with the memory. Voltage and current signals of the power transmission line are directly acquired by adopting the resistance voltage division voltage detection circuit and the resistance type current sampling circuit, mutual inductor equipment does not need to be installed, and the wiring process is simplified.

Description

Technical Field

[0001] The utility model relates to the technical field of electric energy meters, in particular to an intelligent fee-controlled electric energy meter. Background Art

[0002] As part of the intelligent power management system, the remote fee-controlled electricity meter can be used to measure the user's electricity consumption and remotely control meter reading and fee settlement. Compared with traditional electricity meters that require manual door-to-door meter reading, it reduces labor costs and meter reading errors.

[0003] However, currently, most remote cost-controlled electricity meters use transformer sampling to measure and collect user electricity consumption. The voltage signal and current signal of the user are collected through voltage transformers and current transformers respectively. This method requires the layout of transformer equipment in the transmission line, and the wiring is complicated. On the other hand, the transformer may age with the use of time. If it is not replaced in time, there may be errors, the metering accuracy will decrease, resulting in inaccurate electricity consumption measurement, which will in turn affect the final electricity bill settlement. Utility Model Content

[0004] To solve the above-mentioned problems, the utility model provides an intelligent fee-controlled electric energy meter, including a resistor voltage-dividing voltage detection circuit, a resistor current sampling circuit, a digital-to-analog conversion module, a metering chip, a microprocessor, a memory and a calibration pulse module; the output ends of the resistor voltage-dividing voltage detection circuit and the resistor current sampling circuit are respectively electrically connected to the digital-to-analog conversion module, the digital-to-analog conversion module is electrically connected to the input end of the metering chip, and the metering chip is electrically connected to the calibration pulse module; the output end of the metering chip is electrically connected to the microprocessor, and the microprocessor is electrically connected to the memory.

[0005] In a specific implementation, the resistor divider voltage detection circuit includes a differential amplifier and resistors R1, R2, R3, R4, and R5. The positive pole of the load transmission line is connected to ground in series via resistors R3 and R4, and the positive input end of the differential amplifier is connected to the series node of resistors R3 and R4; the negative pole of the load transmission line is connected to ground in series via resistors R1 and R5, and the series node of resistors R1 and R5 is respectively connected to the reverse input end of the differential amplifier and one end of resistor R2, and the other end of resistor R2 is connected to the output end of the differential amplifier.

[0006] The resistive current sampling circuit comprises a detection resistor, a load resistor and an operational amplifier. The detection resistor is connected in series with the load resistor, and two ends of the detection resistor are respectively connected to a positive input terminal and a negative input terminal of the operational amplifier.

[0007] The detection resistor is a manganese copper resistor, which has a low resistance temperature coefficient and changes little due to the influence of current.

[0008] The calibration pulse module comprises a CD4060 frequency divider and a crystal oscillator, wherein the crystal oscillator is electrically connected to the CD4060 frequency divider via a resistor and a capacitor.

[0009] The intelligent fee-controlled electric energy meter also includes an RS485 communication module and a network communication module, and the microprocessor is electrically connected to the RS485 communication module and the network communication module respectively.

[0010] The network communication module is used to communicate with the Internet and can upload data on the total amount of electricity used and the amount of electricity charges.

[0011] The RS485 communication module is used to be electrically connected to the circuit breaker via a cable, and can control the circuit breaker to perform remote opening and closing.

[0012] In order to ensure that the output signals of the resistor divider voltage detection circuit and the resistor current sampling circuit can be converted in real time to avoid queuing, two digital-to-analog conversion modules are provided, and the resistor divider voltage detection circuit and the resistor current sampling circuit are respectively electrically connected to one digital-to-analog conversion module.

[0013] The beneficial effect is that the utility model is an intelligent fee-controlled electric energy meter, which directly collects the voltage and current signals of the transmission line by adopting a resistor voltage-dividing voltage detection circuit and a resistor current sampling circuit, without installing a transformer device, thus simplifying the wiring process. At the same time, the signal is converted and processed by a digital-to-analog conversion module and a metering chip, and the pulse signal of the metering chip is accurately calibrated by a meter calibration pulse module, thereby improving the measurement accuracy and reliability, and ensuring the accuracy of the electric energy meter in measuring the total amount of electricity consumption. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 This is the system structure diagram of the intelligent fee-controlled energy meter;

[0015] Figure 2 is a circuit diagram of a resistor divider voltage detection circuit;

[0016] Figure 3 The circuit diagram of the resistive circuit sampling circuit. DETAILED DESCRIPTION

[0017] Exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings.

[0018] See also Figure 1 This embodiment provides an intelligent fee-controlled energy meter, which is electrically connected to the load transmission line and can directly collect the load power consumption and perform electricity fee statistics; and the intelligent fee-controlled energy meter is electrically connected to the circuit breaker connected in series to the load transmission line, and is used to control the opening and closing of the circuit breaker according to the electricity fee balance.

[0019] The intelligent fee-controlled electric energy meter specifically includes a resistor voltage-dividing voltage detection circuit, a resistor current sampling circuit, a digital-to-analog conversion module, a metering chip, a microprocessor, a memory, and a meter calibration pulse module. The load transmission line is electrically connected to the resistor voltage-dividing voltage detection circuit and the input end of the resistor current sampling circuit respectively, and the output end of the resistor voltage-dividing voltage detection circuit and the resistor current sampling circuit is electrically connected to the digital-to-analog conversion module respectively, and the digital-to-analog conversion module is electrically connected to the input end of the metering chip, and the metering chip is electrically connected to the meter calibration pulse module. The resistor voltage-dividing voltage detection circuit divides the voltage through series resistors, and detects the voltage value of the load transmission line according to the voltage-dividing signal; the resistor current sampling circuit detects the current signal flowing through the load transmission line by using resistors, and obtains the current sampling value by collecting the voltage drop across the resistor and the resistance value. The resistor voltage-dividing voltage detection circuit and the resistor current sampling circuit are digitally converted by the digital-to-analog conversion module respectively, and converted into a pulse signal proportional to the power consumption and transmitted to the metering chip. The metering chip performs time-sharing accumulation according to the pulse signal to obtain the total power consumption of the load transmission line.

[0020] In order to ensure that the output signals of the resistor divider voltage detection circuit and the resistor current sampling circuit can be converted in real time and avoid queuing to cause delays in electricity consumption metering, two digital-to-analog conversion modules are provided, and the resistor divider voltage detection circuit and the resistor current sampling circuit are respectively electrically connected to a digital-to-analog conversion module.

[0021] At the same time, in order to achieve the accuracy of the metering chip's statistics on the input pulse signal, the pulse signal of the metering chip is corrected by a meter calibration pulse module. The meter calibration pulse module includes a CD4060 frequency divider and a crystal oscillator, and the crystal oscillator is electrically connected to the CD4060 frequency divider via a resistor and a capacitor.

[0022] After the metering chip completes the total electricity consumption statistics, the output end of the metering chip is electrically connected to the microprocessor, and the serial communication end of the microprocessor is electrically connected to the memory. The microprocessor stores the electricity fee rate internally, and calculates and processes the total electricity consumption of the load transmission line transmitted by the metering chip to obtain the electricity fee amount, and saves it in the memory.

[0023] In order to facilitate the remote meter reading control of the intelligent fee-controlled energy meter, the intelligent fee-controlled energy meter also includes an RS485 communication module and a network communication module. The microprocessor is electrically connected to the RS485 communication module and the network communication module respectively, and the network communication module is communicatively connected to the Internet. The microprocessor can upload the total electricity consumption and the electricity fee amount stored in the memory to the power grid service platform through the network communication module to realize the remote meter reading of the energy meter. When the Internet detects that the balance of the electricity fee paid by the user is in arrears, a control instruction is sent to the microprocessor through the network communication module, and the RS485 communication module is electrically connected to the circuit breaker through a cable. The microprocessor opens the circuit breaker and cuts off the power through the RS485 communication module until the user completes the electricity fee payment and closes the circuit breaker again through the RS485 communication module.

[0024] As a preferred embodiment, the resistor voltage-dividing voltage detection circuit includes a differential amplifier and resistors R1, R2, R3, R4, and R5. The positive pole of the load transmission line is connected to the ground in series through resistors R3 and R4, and the positive input end of the differential amplifier is connected to the series node of resistors R3 and R4; the negative pole of the load transmission line is connected to the ground in series through resistors R1 and R5, and the series node of resistors R1 and R5 is respectively connected to the reverse input end of the differential amplifier and one end of resistor R2, and the other end of resistor R2 is connected to the output end of the differential amplifier. By dividing the voltage through series resistors and using a differential amplifier to prevent interference from common-mode signals, the two divided voltage signals are differentially processed and amplified to detect the voltage value of the load transmission line.

[0025] The resistive current sampling circuit includes a detection resistor, a load resistor and an operational amplifier. The detection resistor is connected in series with the load resistor. The detection resistor adopts a manganese copper resistor with a low resistance temperature coefficient, and its two ends are respectively connected to the positive input terminal and the reverse input terminal of the operational amplifier. Since the resistance value of the manganese copper resistor changes little with the current, the voltage change generated by the current flowing through the two ends of the manganese copper resistor is detected to achieve accurate detection of the current of the load transmission line.

Claims

1. An intelligent fee-controlled electric energy meter, characterized in that: It includes a resistor-divider voltage detection circuit, a resistor current sampling circuit, a digital-to-analog conversion module, a metering chip, a microprocessor, a memory and a calibration pulse module; the output ends of the resistor-divider voltage detection circuit and the resistor current sampling circuit are respectively electrically connected to the digital-to-analog conversion module, the digital-to-analog conversion module is electrically connected to the input end of the metering chip, and the metering chip is electrically connected to the calibration pulse module; the output end of the metering chip is electrically connected to the microprocessor, and the microprocessor is electrically connected to the memory.

2. The intelligent fee-controlled electric energy meter according to claim 1, characterized in that: The resistor-divider voltage detection circuit includes a differential amplifier and resistors R1, R2, R3, R4 and R5. Resistors R3 and R4 are connected to ground in series, and the positive input end of the differential amplifier is connected to the series node of resistors R3 and R4; resistors R1 and R5 are connected to ground in series, and the series node of resistors R1 and R5 is respectively connected to the reverse input end of the differential amplifier and one end of resistor R2, and the other end of resistor R2 is connected to the output end of the differential amplifier.

3. The intelligent fee-controlled electric energy meter according to claim 1, characterized in that: The resistive current sampling circuit comprises a detection resistor, a load resistor and an operational amplifier. The detection resistor is connected in series with the load resistor, and two ends of the detection resistor are respectively connected to a positive input terminal and a negative input terminal of the operational amplifier.

4. The intelligent fee-controlled electric energy meter according to claim 3 is characterized in that: The detection resistor is a manganese copper resistor.

5. The intelligent fee-controlled electric energy meter according to claim 1, characterized in that: The calibration pulse module comprises a CD4060 frequency divider and a crystal oscillator, and the crystal oscillator is electrically connected to the CD4060 frequency divider via a resistor and a capacitor.

6. The intelligent fee-controlled electric energy meter according to claim 1, characterized in that: It also includes an RS485 communication module and a network communication module, and the microprocessor is electrically connected to the RS485 communication module and the network communication module respectively.

7. The intelligent fee-controlled electric energy meter according to claim 6, characterized in that: The network communication module is used for communication connection to the Internet.

8. The intelligent fee-controlled electric energy meter according to claim 6, characterized in that: The RS485 communication module is used to be electrically connected to the circuit breaker through a cable.

9. The intelligent fee-controlled electric energy meter according to claim 1, characterized in that: The digital-to-analog conversion modules are provided with two, and the resistor voltage-dividing voltage detection circuit and the resistor current sampling circuit are electrically connected to one digital-to-analog conversion module respectively.

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