CN102128977A - Single-phase watt-hour meter supporting two-way communication - Google Patents

Abstract

The invention provides a single-phase electric energy meter supporting two-way communication. The electric energy meter includes: a main control CPU; a data acquisition unit for collecting voltage signals and current signals from power lines; a data processing unit for collecting voltage signals and current signals The current signal is processed to generate voltage quality information and electric energy metering information; the display unit is used to display the voltage quality information and electric energy metering information; the communication device interface is used to connect with a communication device; multiple communication systems are different from each other One of the communication devices is connected to the interface of the communication device for sending the voltage quality information and electric energy metering information to the remote end; the main control CPU controls the data acquisition unit, the data processing unit, the display unit, the interface of the communication device and the connection with the interface of the communication device work of the communication device. It is used to realize a single-phase electric energy meter that supports multiple communication systems and does not need to change any single-phase electric energy meter software and hardware.

Description

A single-phase watt-hour meter supporting two-way communication

technical field

The present invention relates to electric energy metering technology of electric power system, in particular to household single-phase electric energy meter technology, specifically a single-phase electric energy meter supporting two-way communication.

Background technique

With the construction and development of the smart grid, power companies need to know more about the electricity consumption of household users and the operation status of metering equipment. However, the single-phase energy meters for residents in the prior art only support simple metering, prepayment and other functions, and cannot meet the requirements of more information interaction of power companies.

Contents of the invention

An embodiment of the present invention provides a single-phase electric energy meter supporting two-way communication to realize a single-phase electric energy meter supporting multiple communication systems without changing any software and hardware of the single-phase electric energy meter.

The purpose of the embodiments of the present invention is to provide a single-phase electric energy meter supporting two-way communication, the electric energy meter includes: a main control CPU; a data acquisition unit for collecting voltage signals and current signals from power lines; a data processing unit for Processing the collected voltage signal and current signal to generate voltage quality information and electric energy metering information; a display unit for displaying the voltage quality information and electric energy metering information; a communication device interface for communicating with a communication device Connection; a plurality of communication devices with different communication standards, select one of the communication devices with different communication standards to connect with the interface of the communication device, and use the voltage quality information and electric energy metering The information is sent to the remote end; the main control CPU controls the work of the data collection unit, data processing unit, display unit, communication device interface and the communication device connected to the communication device interface.

The effect of the embodiments of the present invention is to realize a single-phase electric energy meter supporting multiple communication modules, and to support hot swapping of each communication module. The single-phase electric energy meter of the present invention can not only support the most mainstream communication mode at present, but also can replace modules according to different requirements without changing any software and hardware of the single-phase electric energy meter, thereby greatly reducing development, production and maintenance costs. The present invention proposes to use broadband wireless (McWiLL), GPRS, power line carrier and small wireless communication methods, through event detection circuits and algorithms, so that the electric energy meter can automatically detect abnormal electricity consumption, electricity theft, and electric meter failure, etc., and actively report function, which solves the disadvantages of manual meter reading and greatly improves work efficiency and power supply service quality. At the same time, the energy meter can be used as a communication medium to realize the two-way real-time communication function between the display terminal-the energy meter-the main station, and realize the two-way interaction between the power user and the power company without any additional communication medium, satisfying the intelligent Grid construction needs.

Description of drawings

The drawings described here are used to provide further understanding of the present invention, constitute a part of the application, and do not limit the present invention. In the attached picture:

Fig. 1 is the structural block diagram of the single-phase electric energy meter that supports two-way communication of the present invention;

Fig. 2 is a schematic diagram of the appearance of a single-phase electric energy meter supporting two-way communication in the present invention;

3a to 3d are structural block diagrams of the communication device of the present invention;

Fig. 4 is a structural block diagram of a single-phase electric energy meter supporting two-way communication according to an embodiment of the present invention;

5 is a schematic diagram of an interface of a remote communication device according to an embodiment of the present invention;

FIG. 6 is a schematic diagram of definition of interface pins of a remote communication device according to an embodiment of the present invention;

Fig. 7 is the interface circuit diagram of the photoelectric isolation and remote communication device of the embodiment of the present invention;

8 is a schematic diagram of an event sensor of an electric energy meter according to an embodiment of the present invention;

FIG. 9 is a circuit diagram of a cover opening sensing circuit according to an embodiment of the present invention;

FIG. 10 is a circuit diagram of a relay and a zero-crossing detection circuit according to an embodiment of the present invention.

Detailed ways

In order to make the object, technical solution and advantages of the present invention clearer, the embodiments of the present invention will be further described in detail below in conjunction with the accompanying drawings. Here, the exemplary embodiments and descriptions of the present invention are used to explain the present invention, but not to limit the present invention.

As shown in Figure 1, the single-phase watt-hour meter supporting two-way communication of the specific embodiment of the present invention comprises: main control CPU104, and data acquisition unit 101 is used for collecting voltage signal and current signal from power line; Data processing unit 102 is used for collecting The voltage signal and current signal are processed to generate voltage quality information and electric energy metering information; the display unit 103 is used to display the voltage quality information and electric energy metering information; the communication device interface 105 is used to connect with a communication device; Communication devices (106a, 106b, 106c, 106d) with different communication standards from each other, select one of the communication devices (106a, 106b, 106c, 106d) with different communication standards to connect with the communication module interface 105 for connecting The voltage quality information and electric energy metering information are sent to the remote end; the main control CPU 104 controls the work of the data acquisition unit 101, the data processing unit 102, the display unit 103, the communication device interface 105 and the communication device connected with the communication device interface.

As shown in Figure 2, it is a schematic diagram of the appearance of a single-phase electric energy meter 200 supporting two-way communication according to a specific embodiment of the present invention. The single-phase electric energy meter 200 includes: a display screen 201, a communication device slot 202, and communication device interfaces (202a and 202b ), the communication device interface 202a is a data line interface, the communication device interface 202b is a power line interface, and the communication device interfaces 202a and 202b can also be combined into one interface.

In Fig. 2, the communication device is a modular design, using common interface definitions, it can support GPRS, broadband wireless (McWiLL), low-voltage power line carrier and short-distance micro-power wireless at the same time. The transmission data adopts the method of transparent forwarding. The communication unit of the energy meter body performs data analysis and framing according to specific communication protocols. The communication device is only responsible for forwarding the communication frames according to the corresponding communication methods, so that more communication methods in the future can be It can be seamlessly connected to the uplink channel of the energy meter. The communication device includes: a GPRS communication device 203a, a 3G communication device 203b, a carrier communication device 203c and a short-distance wireless communication device 203d. According to the current communication environment of the energy meter, select an available communication device among the GPRS communication device 203a, 3G communication device 203b, carrier communication device 203c and short-range wireless communication device 203d to connect to the communication device interfaces 202a and 202b.

As shown in Fig. 3a, the GPRS communication device includes: CPU 303a, serial interface 302a, LED indicator light 304a, watchdog circuit 306a, memory 305a and McWiLL module 301a. GPRS General Packet Radio Service (General Packet Radio Service) is a wireless packet switching technology based on the GSM system. Although GPRS technology is a transitional technology for the evolution of the existing GSM network to the third generation of mobile communication, it has advantages in many aspects. GPRS technology is suitable for more data services, such as mobile office, Internet access, etc., and has advantages in transmission rate, wireless resource management, and billing. Through GPRS communication, the direct communication between the electric energy meter and the main station can be realized without other equipment for transfer.

As shown in Fig. 3b, the 3G communication device includes: CPU 303b, serial interface 302b, LED indicator light 304b, watchdog circuit 306b, memory 305b and GPRS communication module 301b. The 3G communication module 301b can adopt the McWiLL (Multi-Carrier Wireless Information Local Loop) module, and the McWiLL module is a broadband evolution version of SCDMA integrated wireless access technology. The McWiLL module can support voice services, data services, and multimedia at the same time, and is a broadband wireless access system integrating voice and data. McWiLL single base station occupies 5MHz carrier frequency bandwidth, the maximum throughput is 15Mbit/s, the maximum terminal throughput is 3Mbit/s, and can support up to 300 simultaneous voice channels. It is currently a commercially available broadband wireless access system that supports mobility. . It can realize the real-time direct interaction between the energy meter and the main station.

As shown in Fig. 3c, the carrier communication device includes: CPU 303c, serial interface 302c, LED indicator light 304c, watchdog circuit 306c, memory 305c and 3G communication module 301c. Power carrier communication module PLC, commonly known as "power line Internet access", mainly refers to a communication method that uses power lines to transmit data and voice signals. Its advantage is low implementation cost, because the existing power distribution network can be directly used as the transmission line, so no additional wiring is required, which greatly reduces the network investment and cost. Powerline is the network with the widest reach, and its scale is unmatched by any other network. PLC can easily penetrate into every family, creating great space for the development of the Internet. PLC can provide high-speed transmission. At present, its transmission rate is between 4.5M and 45Mbps, which is much higher than dial-up and ISDN, and can support the application on the existing network.

As shown in Fig. 3d, the short-distance wireless communication device includes: CPU 303d, serial interface 302d, LED indicator light 304d, watchdog circuit 306d, memory 305d and short-distance wireless communication module 301d. Short-range wireless communication refers to: all wireless network communications whose transmission range is equal to or less than the range specified by the IEEE 802.11 and 802.15 standards. Short-range wireless communication is faster, cheaper and consumes less power than wireless data transmission of third-generation cellular devices.

The above four communication methods can meet the communication requirements of electric energy meters in different power consumption environments, improve the reliability of the communication system, and also enable the full collection and full coverage of residential users' electricity consumption information.

Example

As shown in Figure 4, the electric energy meter of this embodiment includes: a main control CPU 404, a data acquisition unit 401 for collecting voltage signals and current signals from the power line; a data processing unit 402 for processing the collected voltage signals and current signals, Generate voltage quality information and electric energy metering information; the display unit 403 is used to display the voltage quality information and electric energy metering information; the remote communication device interface 405 is used to connect with a communication device; multiple communication devices with different communication formats (406a , 406b, 406c, 406d), select one of a plurality of communication devices with different communication modes to connect with the remote communication device interface 405, and send the voltage quality information and electric energy metering information to the remote end; the main control CPU404 controls the data The collection unit 401 , the data processing unit 402 , the display unit 403 , the remote communication device interface 405 and the communication device connected to the communication device interface 405 work.

The electric energy meter of this embodiment further includes: a photoelectric isolation circuit 407 , and the remote communication device interface 405 is connected with the main control CPU 404 through the photoelectric isolation circuit 407 .

The electric energy meter of this embodiment also includes: an event sensor 410 is used to detect the local event signal of the electric energy meter, and transmits the event signal to the data processing unit 402 to generate event alarm information, and the event alarm information is sent to the remote end by the communication device . The event sensor 410 includes: an electric energy meter cover opening sensing circuit, an electric energy meter battery undervoltage sensing circuit and/or an electric energy meter temperature sensor.

The electric energy meter of this embodiment also includes: a switch control unit 409, and the switch control unit 409 includes: a relay and a zero-crossing detection circuit; wherein, the zero-crossing detection circuit collects fault signals and operating status signals from the power line, and The fault signal and the running state signal are transmitted to the main control CPU 404, and the main control CPU 404 controls the action of the relay according to the fault signal and the running state signal.

The electric energy meter in this embodiment further includes: a local communication unit 412 configured to send voltage quality information and electric energy metering information to a near-end communication device. The local communication unit includes: infrared communication module, RS485 communication module, M-BUS communication module or ZigBee communication module.

The energy meter in this embodiment also includes: a keyboard 408 and an interface 411 for an electricity purchase card.

The interface of the communication device of the electric energy meter in this embodiment supports hot plugging, and the electric energy meter can simultaneously support communication systems such as GPRS, 3G, carrier wave, and short-distance wireless communication. Because the carrier is partially different from the communication interface of GPRS and 3G, the electrical interface of the energy meter is designed to be compatible with 4 kinds of modules at the same time. The interface socket arrangement between the communication device and the energy meter is shown in Figure 5.

As shown in Figure 6, it is a schematic diagram of the definition of the interface pins of the remote communication device; wherein, MRX is the signal pin (5V TTL level) for the communication device to receive the electric energy meter CPU; MTX is the signal pin (5V TTL level) for the communication device to send the electric energy meter CPU level); MGND is the communication ground; MDC5V is the analog power supply of GPRS, 3G and carrier, provided by the electric energy meter. MDC12V is another power supply of the carrier, compatible with 5V carrier module and 12V carrier module; 1ZBSET is the setting signal pin of the carrier (compatible with 5V and 12V level); 1ZBRST is the reset signal pin of the carrier (compatible with 5V and 12V level).

As shown in Figure 7, the photoelectric isolation and remote communication device interface circuit diagram; the optocoupler isolation circuit is used between the main control CPU and the communication device to ensure the safety of hot swapping. At the same time, the use of standard UART pins ensures the replaceability of different communication modules. In the case of no power failure, after replacing other communication modules, the communication channel can be switched automatically, and the master station will be notified via the new communication medium that the communication device of the single-phase electric energy meter has been replaced. The modular design of the communication interface can meet the requirements of communication device interchange and support the seamless access of more communication methods. The software and hardware design has a unified level interface, parameters, and a unified program interface to ensure seamless access.

As shown in Figure 8, the electric energy meter of this embodiment also includes: an event sensor, which is used to detect the local event signal of the electric energy meter, and transmits the event signal to the data processing unit to generate event alarm information, and the event alarm is reported by the communication device The information is sent to the remote end. The event sensor includes: a sensor circuit for opening the cover of the energy meter, a sensor circuit for undervoltage of the battery of the energy meter, and/or a temperature sensor for the energy meter.

The electric energy meter has the functions of detecting the meter cover and opening the terminal cover. As shown in Figure 9, the IO port of the main control CPU is connected to the KBGJL port as an input port. Through the sensor, K4 can detect whether the terminal cover of the ammeter is opened, that is, when the terminal cover is opened, K4 is closed; when the terminal cover is closed, K4 is disconnected. The main control CPU detects the state of K4 every 1 second. Once it is in the disconnected state and exceeds the set number of times, it will be regarded as an opening event and recorded. It can be seen from Figure 9 that when the terminal cover is not opened, the KBGJL signal connected to the main control CPU is always high (equal to VCP voltage), and when the terminal cover is opened, the KBGJL signal connected to the main control CPU is grounded (DGND) through K4 , completed the detection of the open cover. After the main control CPU detects the cover opening event, it can immediately report the event to the master station.

Battery undervoltage reporting function: Battery is a 3.6V battery symbol, which provides 3.3V power for the main control CPU and memory after being stepped down by a diode. Two 10M large resistors R73 and R74 reduce the battery voltage to half, and send the voltage BT3CHK to the sampling port of the main control CPU. The value obtained by the main control CPU through 10-bit high-speed A/D sampler The reference voltage is compared to obtain an accurate battery voltage value. If the battery voltage value is lower than a certain critical point, the main control CPU immediately reports the battery undervoltage event to the main station, and notifies the power supply company to replace the battery in time.

Abnormal temperature reporting: Use the intelligent temperature sensor chip TCN75 to detect real-time temperature. If the temperature is abnormal, the electric energy meter can report the abnormal situation. TCN75 is a serial programmable temperature sensor, when the ambient temperature exceeds the set point programmed by the user, it can be sent to the main control CPU of the energy meter through the 2-wire bus IIC_SDA and IIC_SCL.

As shown in Figure 10, it is a circuit diagram of a relay and a zero-crossing detection circuit. Among them, CS5463 is a zero-crossing signal detection chip. The INT pin of CS5463 can be used to notify CS5463 that certain events have occurred, these events include the status of the chip running and internal fault status. The combination of status register and mask register will generate INT signal. After the 220V mains signal UN passes through the resistor network R20, R21, R22, R23, R24, R25, R26, R27, it is transformed into a sine wave signal with an amplitude of about 2V and input to the differential input signal source VIN+ and VIN- ports of CS5463. Completed the real-time sampling of the mains.

In this embodiment, the trigger mode of the INT pin is configured to be valid at the rising edge, and the INT port of the CS5463 is connected to the middle port INT1 of the main control CPU. When the sinusoidal waveform of UN turns from the negative terminal to the positive terminal and just passes through the zero point, CS5463 immediately sends a pulse signal to the INT port. After the port INT1 in the main control CPU receives the signal, it immediately enters the interrupt service subroutine to complete the real-time monitoring of the mains zero-crossing signal. Due to the adoption of the above-mentioned zero-cross detection technology, this circuit has the characteristic of disconnecting the relay when the voltage crosses zero. Therefore, it can effectively solve the problem of relay under capacitive and inductive conditions, reduce the arc generated between the live wire and the neutral wire of the relay, and greatly increase the reliability and life of the relay.

The heat dissipation method of the relay, the reasonable space layout of the relay, there is a large space around the relay, the relay and the bottom case are not in direct contact, and the installation position of the relay considers air convection, which is more conducive to heat dissipation. The interface of live wire and neutral wire at the outer end of the relay uses symmetrical thick copper strips, which is good for heat conduction. The cooperation of the relay and the shunt handles the influence of the external magnetic field well.

The power supply of the communication system of the single-phase electric energy meter in this technical solution can meet the requirement of zero shutdown, and the power supply module has the function of hot swapping to meet the requirement of zero shutdown. The hot-plug requirement is also to prevent system errors. However, since different modules have different characteristics, this technology meets the following hardware requirements:

1) When performing hot swapping, the hardware can withstand the impact of instantaneous surge voltage and surge current, and eliminate sparks between sockets.

2) After hot-swapping, the load of the hardware system of the single-phase electric energy meter takes over smoothly to prevent the adjustment of the output voltage from being affected by a sudden change. The specific hardware design includes the definition of the module interface, the interface circuit design of the electric energy meter communication module and the design of the communication part.

The embodiment of the present invention makes the software and hardware of the single-phase electric energy meter compatible with various communication modules at the same time; and various communication modules are hot-swappable; the electric energy meter can actively report events; the electric energy meter is used as a communication medium to transmit information such as messages, data, and voice. The embodiment of the present invention supports multiple communication modes, and can be simultaneously compatible with four channels of low-voltage power line carrier, GPRS, short-range wireless communication and broadband wireless communication (McWiLL). When replacing the communication module, the single-phase energy meter does not need to be powered off, and there is no need to change any software and hardware design, which meets the needs of future smart grid construction. Through the two-way communication of the energy meter, the energy meter can actively report events in real time, and can also provide communication media to transmit text messages, voice and video and other data transmission functions.

The specific embodiments described above have further described the purpose, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above descriptions are only specific embodiments of the present invention and are not intended to limit the scope of the present invention. Protection scope, within the spirit and principles of the present invention, any modification, equivalent replacement, improvement, etc., shall be included in the protection scope of the present invention.

Claims (10)

1. A single-phase watt-hour meter supporting two-way communication, said watt-hour meter comprising: a main control CPU; it is characterized in that said watt-hour meter also includes: A data acquisition unit for collecting voltage signals and current signals from the power line; The data processing unit is used to process the collected voltage signal and current signal to generate voltage quality information and electric energy metering information; a display unit, configured to display the voltage quality information and electric energy metering information; a communication device interface for connecting with a communication device; A plurality of communication devices with different communication standards, one of the plurality of communication devices with different communication standards is selected to be connected to the interface of the communication device for sending the voltage quality information and electric energy metering information to remote; The main control CPU controls the operation of the data collection unit, the data processing unit, the display unit, the communication device interface and the communication device connected to the communication device interface. 2. The electric energy meter according to claim 1, wherein the plurality of communication devices with different communication standards include: GPRS communication device, 3G communication device, carrier communication device and short-distance wireless communication device. 3. The electric energy meter as claimed in claim 2, wherein said GPRS communication device comprises: CPU, serial interface, LED indicator light, watchdog circuit, memory and GPRS communication module; The 3G communication device includes: CPU, serial interface, LED indicator light, watchdog circuit, memory and 3G communication module; The carrier communication device includes: CPU, serial interface, LED indicator light, watchdog circuit, memory and power line carrier communication module; The short-distance wireless communication device includes: CPU, serial interface, LED indicator light, watchdog circuit, memory and short-distance wireless communication module. 4. The electric energy meter according to claim 1, characterized in that, the electric energy meter further comprises: a photoelectric isolation circuit, and the communication device interface is connected to the main control CPU through the photoelectric isolation circuit . 5. The electric energy meter according to claim 1, characterized in that, the electric energy meter further comprises: an event sensor for detecting local event signals of the electric energy meter, and transmitting the event signals to the The data processing unit generates event alarm information, and the communication device sends the event alarm information to the remote end. 6. The electric energy meter according to claim 5, wherein the event sensor comprises: an electric energy meter opening sensing circuit, an electric energy meter battery undervoltage sensing circuit and/or an electric energy meter temperature sensor. 7. The electric energy meter as claimed in claim 1, characterized in that, said electric energy meter further comprises: a relay and a zero-crossing detection circuit; wherein, The zero-crossing detection circuit collects fault signals and operating state signals from the power line, and transmits the fault signals and operating state signals to the main control CPU, and the main control CPU The fault signal and the running state signal control the action of the relay. 8. The electric energy meter according to claim 1, further comprising: a local communication unit, configured to send the voltage quality information and electric energy metering information to a near-end communication device. 9. The electric energy meter according to claim 8, wherein said local communication unit comprises: an infrared communication module, an RS485 communication module, an M-BUS communication module or a ZigBee communication module. 10. The electric energy meter according to claim 1, characterized in that, the electric energy meter further comprises: a keyboard and an interface for a power purchase card.

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