CN207457341U - Three-phase and four-line RF intelligent electric meters - Google Patents

Abstract

The utility model proposes three-phase and four-line RF intelligent electric meters, belong to intelligent electric meter field, including ammeter main control chip, A roads metering module, B roads metering module, C roads metering module, the RF communication modules being electrically connected with the ammeter main control chip, it further includes the LCD display module being connected on the ammeter main control chip, detection of power loss module, data memory module, pulse outgoing management module and the power module for being used for power supply is electrically connected with A roads metering module, B roads metering module, C roads metering module, ammeter main control chip.By using the chip of integrated multiple functions, using fit designing scheme, the structure of three-phase and four-line RF intelligent electric energy meters is simplified, while improves the reliability of three-phase and four-line RF intelligent electric energy meters.

Description

Three-phase and four-line RF intelligent electric meters

Technical field

The utility model belongs to intelligent electric meter field, more particularly to three-phase and four-line RF intelligent electric meters.

Background technology

Currently, RF（Radio Frequency, radio frequency）The electric energy meter of the discrete design scheme of communication generally uses microcontroller Device unit（Micro control unit, MCU）Add the compositions such as computation chip plus independent RF communication modules.It is wherein independent RF communication modules are generally made of RF chips and a individual low capacity MCU, wherein MCU of the control RF chips by low capacity It completes, is simply used with main MCU as serial ports, the transmission of data is all transparent transmission.With the development of intelligent grid, electricity Energy table market further promotes the performance requirement of intelligent electric meter, and the requirement of cost is higher and higher, and existing discrete design is Can not meet the needs of novel intelligent electric meter.It is obvious that there are of high cost, hardware circuits for the existing discrete design scheme of electric energy meter The defects of complexity, poor reliability.

Utility model content

In order to solve shortcoming and defect in the prior art, the utility model provide it is a it is at low cost, circuit is simple Single three-phase and four-line RF intelligent electric energy meters reliable, communication distance is remote, low in energy consumption.

In order to reach above-mentioned technical purpose, the utility model provides three-phase and four-line RF intelligent electric energy meters, the three-phase four Line RF intelligent electric energy meters, including：Ammeter main control chip, the A roads metering module being electrically connected with the ammeter main control chip, B roads meter Module, C roads metering module, RF communication modules are measured, the LCD display module being connected on the ammeter main control chip is further included, falls Electro-detection module, data memory module, pulse outgoing management module and with A roads metering module, B roads metering module, C roads count Measure module, the electrical connection of ammeter main control chip is used for the power module of power supply.

Optionally, the meter main control chip is HT6015 chips.

Optionally, the A roads metering module, B roads metering module, C roads metering module is using single-phase measurement chip RN8207C。

Optionally, the RF communication modules are using unlimited transceiving chip SX1276.

Optionally, the RF communication modules are by GPIO mouthfuls of communications with ammeter main control chip.

Optionally, A roads metering module, B roads metering module, C roads metering module include voltage sampling circuit and electricity Flow sample circuit.

The advantageous effect that technical solution provided by the utility model is brought is：By using the chip of integrated multiple functions, Using fit designing scheme, the structure of three-phase and four-line RF intelligent electric energy meters is simplified, improves its reliability, meanwhile, have Low in energy consumption, the characteristics of wireless transmission distance is remote, during the networking of RF systems, play very crucial effect.

Description of the drawings

It, below will be to needed in embodiment description in order to illustrate more clearly of the technical solution of the utility model Attached drawing is briefly described, it should be apparent that, the accompanying drawings in the following description is only some embodiments of the utility model, for For those of ordinary skill in the art, without creative efforts, other are can also be obtained according to these attached drawings Attached drawing.

Fig. 1 is the structure diagram of three-phase and four-line RF intelligent electric meters provided by the utility model；

Fig. 2 is the structure diagram of voltage sampling circuit provided by the utility model；

Fig. 3 is the structure diagram of current sampling circuit provided by the utility model；

Fig. 4 is the structure diagram of RF communications GPIO circuits provided by the utility model；

Fig. 5 is Communication processing flow chart provided by the utility model.

Specific embodiment

To make the structure of the utility model and advantage clearer, the structure of the utility model is made below in conjunction with attached drawing It is further described through.

The utility model provides a kind of three-phase and four-line RF intelligent electric meters, as shown in Figure 1, three-phase and four-line RF intelligence electricity Table, including：Ammeter main control chip, the A roads metering module being electrically connected with the ammeter main control chip, B roads metering module, C roads meter Measure module, RF communication modules, further include the LCD display module being connected on the ammeter main control chip, detection of power loss module, Data memory module, pulse outgoing management module and with A roads metering module, B roads metering module, C roads metering module, ammeter Main control chip electrical connection is used for the power module of power supply.

In force, the A roads metering module, B roads metering module, C roads metering module, is communicated by serial bus Mode with ammeter main control chip communicate, the data of metering are transmitted to ammeter main control chip.Pulse outgoing management module, to needing The management that the active and idle pulse of output is exported.LCD display module, the different information that display client needs.Power down is examined The power down of ammeter is detected survey module and the management of event.The data memory module includes ferroelectricity chip and EEPROM It is memory module, the data such as electricity, event is managed.Most important module is RF modules, it is as integrated kilowatt meter reading-out system Most important module realizes same low-power consumption Wide Area Netweork（LPWAN）On equipment communicated and the requirement of interactive function.RF Communication module between CPU pass through GPIO mouthfuls communication.

The ammeter main control chip is HT6015 chips, and corresponding RF communication function modules is coordinated to complete the transmission of data Etc. functions.HT6X1X series is multi-functional, high-performance, the MCU chip of the special 128K of low-power consumption single-phase intelligent ammeter, is internally integrated Cortex-M0 processors, Clock management, power management, hardware auto thermal compensation RTC, PLL, high frequency RC, low frequency RC, LCD Units and NVIC the and DEBUG debugging functions such as driving.Wherein, support the RTC units of compensation mechanism per second, chip with 32.768KHz crystal oscillator clocks source is as RTC clock source, the clock automatic digital compensating unit integrated by chip internal, assists User realizes the automatic compensation of RTC in the case where being participated in without its software.

The A roads metering module, B roads metering module, C roads metering module using single-phase measurement chip RN8207C, The function of the chip： 1）RN8207C can measure active power, reactive power, active energy, quadergy, and can provide electricity Virtual value, voltage effective value, line frequency, zero passage interruption etc. are flowed, can realize flexible anti-electricity-theft scheme.2）RN8207C is supported Digital gain, phase and offset corrections.Active energy pulse is exported from PF pins.Reactive energy pulse can pass through interruption Mouth exports after software processing.3）RN8207C provides serial interface UART, and fixed baud rate 4800, pin resets and UART Input pin RX is multiplexed.4）The reliable work of chip when power supply supervisory circuit inside RN8207C can ensure to power on and power off Make.

The RF communication modules are mainly remotely adjusted using unlimited transceiving chip SX1276, the transceiver using LoRa Modulator-demodulator, for extra long distance spread spectrum communication, strong interference immunity can reduce current drain to greatest extent.By liter special LoRaTM patent modulation techniques, SX1276/77/78 is using the height that the crystal and material of low cost can be more than -148dBm Sensitivity.In addition, the highly sensitive integrated link budget for making these devices with 20dBm power amplifiers has reached industry neck It is first horizontal, become the optimal selection of remote transmission and the application high to reliability requirement.Conventional modulated technology is compared, LoRaTM modulation techniques also have a clear superiority in terms of antiblocking and selectivity, and solving traditional design scheme can not be simultaneous simultaneously The problem of caring for distance, anti-interference and power consumption.These devices also support the high-performance of the systems such as WM-Bus and IEEE802.15.4g (G) FSK patterns.Compared with similar device, SX1276/77/78 is also significantly optimized on the basis of current drain is greatly reduced Phase noise, selectivity, the receiver linearity, three ranks input intercept point（IIP3）Wait properties.

Three-phase and four-line RF intelligent electric meter functions are broadly divided into the parts such as display, metering, communication.Voltage, current signal warp Sample circuit is input to main control chip, and the ginsengs such as power factor, electric current, frequency, requirement, voltage are obtained by corresponding calculate of mathematics Number, by RF communication interface and external communication, while records event information and electricity data and carries out interaction of human-computer interaction etc.. Main functional circuit unit is described in detail below.

The A roads metering module, B roads metering module, C roads metering module includes voltage sampling circuit respectively and electric current is adopted Sample circuit.

The voltage sampling circuit is as shown in Fig. 2, UA roads voltage is depressured by resistance pressure-dividing network and resistance capacitance （Resistor-capacitor, RC）Low-pass filter circuit is input to computation chip.In voltage sampling circuit, resistance R40, R41, R42, R46, R47, R48, R49, R50 are voltage resistance, are generated at resistance R51 and R66 both ends with inputting external electrical The low voltage signal of ratio reduction is pressed into, since computation chip simulates AD input voltages amplitude no more than 750mV, resistance is set It must be that external signal is reduced to Analog-digital Converter to count value（Within input range.Then voltage signal pass through by The RC network of R51, R66, C34, C42 composition carries out anti-aliasing filter with filtering interference signals, finally by the string of computation chip Mouth is input to Master control chip.The voltage sampling circuit on UB, UC road can similarly obtain voltage differential signal and arrive computation chip Serial ports mouth, then to Master control chip.

The current sampling circuit as shown in figure 3, including：A roads electric current passes through current transformer（Current Transformer, CT）, load resistance and RC low-pass filter circuits be input to computation chip.Current signal passes through Current Mutual Inductance For device CT into current sampling circuit, wherein resistance R16 and R34 is the load resistance of current transformer, for by transformer secondary The electric current of coil is converted to voltage signal, while signal is adjusted to ADC input ranges.Current sampling signal is through RC low-pass filtering The differential pin of computation chip is input to after circuit filtering.B roads, the current sampling circuit on C roads also can similarly obtain.

The RF communication modules are by GPIO mouthfuls of communications with ammeter main control chip, and the RF communicates GPIO mouthfuls of circuits As shown in figure 4, including current-limiting resistance R18, R19, R20, R69, R70 between connection HT6015 chips and SX1276, Yi Jifu Position circuit, the reset circuit is by connecting the resistance R5 between HT6015 chips and SX1276, the resistance being connected with resistance R5 R6 and capacitance C68 compositions, the resistance R6 other ends are connected with 3.6V power supplys, capacitance C68 other ends ground connection；Wherein RF_SCLK is the end pipe foot of HT6015 and SX1276.

Physical interface is defined as follows shown in table：

In order to preferably play the performance of module, recommendation 3.3V, each pin electricity of module is preferred in modular power source voltage Pressure is no more than 3.9V, and no it will cause module permanent damages.Before module powers on, in addition to power pins, it is ensured that other pins electricity Pressure does not exceed (VDD+0.3), and otherwise module cannot normally start.Power supply specific requirement is as follows：

1) voltage accuracy：Better than 9%, i.e., when module works, voltage is not below 3.0V, and otherwise radio frequency power output can subtract It is small；

2) source current：Module T-time peak current<30mA, but the time is very short.So source current capacity is at least There are 30mA fan-out capabilities, if power is limited really, large bulk capacitance can be placed the modular power source near-end, to improve more Power supply stability；

3) power supply ripple：<100mV；Ripple will influence greatly very much communication efficiency；

4) power supply type：Linear stabilized power supply is preferred in power supply, if using Switching Power Supply, it is noted that filtering, it is ensured that Voltage accuracy and ripple value reach requirement.

The RF Communication processing flows of GPIO mouthfuls of three-phase and four-line RF intelligent electric meters are as shown in Figure 5.

Communication processing flow is as shown in Figure 5.

First, GPIO mouthfuls are detected after startup and sends whether data terminate, if terminated, GPIO mouthfuls of initiating communications data permit Perhaps processing time assigns initial value, conversely, directly judge to receive data whether time-out or transmission data；

Secondly, judge receive data whether time-out and also without send data, if so, receive opening flag reset, connect Delay flag clear is received, receives and terminates set, conversely, directly judging whether GPIO mouthfuls of receptions terminate；

Again, judge whether GPIO mouthfuls of receptions terminate, if so, GPIO mouthfuls of interruptions are closed, when then handling communication data Between assign initial value, and by the processing parsing of IEC stipulations communication data, conversely, directly terminating flow；

Finally, judge that communication data allows processing time whether to reach, if so, by GPIO mouthfuls of initialization, then terminate Flow, if not, directly terminating flow.

What the LCD display module was selected is BL55077A chips, and the HT6015 is the same as passing through I2C between BL55077A Bus is communicated.

The three-phase and four-line RF intelligent electric meter clock units are that the hardware RTC block integrated using HT6015 realizes clock Calendar function.

The utility model proposes three-phase and four-line RF intelligent electric meters, have the characteristics that low in energy consumption, wireless transmission distance is remote, During the networking of RF systems, very crucial effect is played.It can be used for business to measure, reactive energy can be tested, had The real time electrical quantities data such as work(electric energy, voltage, electric current, power, frequency, and measurement accuracy meets 1 grade of three-phase of IEC62053-21 The demand of technical standard of electric energy meter.By using the chip of integrated multiple functions, the structure of intelligent electric meter is simplified, is improved simultaneously The reliability of intelligent electric meter.

The above description is only the embodiments of the present invention, is not intended to limit the utility model, all in the utility model Spirit and principle within, any modifications, equivalent replacements and improvements are made should be included in the protection model of the utility model Within enclosing.

Claims (4)

1. three-phase and four-line RF intelligent electric meters, which is characterized in that the three-phase and four-line RF intelligent electric meters, including：Ammeter master control core Piece, the A roads metering module being electrically connected with the ammeter main control chip, B roads metering module, C roads metering module, RF communication modules, It is defeated to further include the LCD display module being connected on the ammeter main control chip, detection of power loss module, data memory module, pulse Go out management module and be electrically connected to supply with A roads metering module, B roads metering module, C roads metering module, ammeter main control chip The power module of electricity, the main control chip are HT6015 chips, and the A roads metering module, B roads metering module, C roads are measured Module is using single-phase measurement chip RN8207C, and the RF communication modules are using unlimited transceiving chip SX1276, institute The RF communication modules stated are by GPIO mouthfuls of communications, A roads metering module, B roads metering module, C with ammeter main control chip Road metering module includes voltage sampling circuit and current sampling circuit.

2. three-phase and four-line RF intelligent electric meters according to claim 1, which is characterized in that the same ammeter of RF communication modules Main control chip communicates GPIO mouthfuls of circuits by the circuit of GPIO mouthfuls of communications for RF, and the RF, which communicates GPIO mouthfuls of circuits, includes connection Current-limiting resistance R18, R19, R20, R69, R70 and reset circuit between HT6015 chips and SX1276, reset electricity Resistance R5, the resistance R6 being connected with resistance R5 and capacitance C68 between routing connection HT6015 chips and SX1276 are formed, described The resistance R6 other ends be connected with 3.6V power supplys, capacitance C68 other ends ground connection, wherein RF_SCLK for HT6015 and The end pipe foot of SX1276.

3. three-phase and four-line RF intelligent electric meters according to claim 1, which is characterized in that the voltage sampling circuit includes Divider resistance R40, R41, R42, R46, R47, R48, R49, R50 and the RC network being made of R51, R66, C34, C42.

4. three-phase and four-line RF intelligent electric meters according to claim 1, which is characterized in that the current sampling circuit includes For electric current by current transformer, load resistance and RC low-pass filter circuits, the load resistance is R16 and R34, the RC Low-pass filter circuit is made of R8, R36, C25, C27.