阅读说明：本技术 一种直接接入式直流电能表 (Direct access type direct current electric energy meter ) 是由 李熊 姚力 章江铭 刘炜 陆春光 肖涛 王朝亮 李亦龙 蒋群 宋磊 黄荣国 于 2021-08-12 设计创作，主要内容包括：本发明公开了一种直接接入式直流电能表,属于电能计量技术领域。现有的内置式分流器实现,为了便于信号准确采集,通常采用大阻值的分流电阻,导致流通大电流时,会产生较多热量,影响电能表计量精度。本发明的一种直接接入式直流电能表,包括壳体、分流器、多芯模组。本发明设置一种具有35μΩ-45μΩ分流电阻的分流器,同时设置至少具有0.1级精度的模数转换芯片,实现所述分流器信号的准确计量采集,进而能有效降低分流器热损耗,提高整体电能计量的准确度。相对于传统直流电能计量模块,本发明的分流器内置组装,充分利用装置内部空间,分流器与多芯模组进行空间隔离,有效降低分流器温升对于电路工作的影响。(The invention discloses a direct access type direct current electric energy meter, and belongs to the technical field of electric energy metering. The existing built-in shunt is realized, and in order to facilitate accurate signal acquisition, a shunt resistor with a large resistance value is usually adopted, so that more heat can be generated when large current flows, and the metering precision of the electric energy meter is influenced. The invention relates to a direct access type direct current electric energy meter which comprises a shell, a current divider and a multi-core module. The invention provides the current divider with the 35 mu omega-45 mu omega shunt resistance, and the analog-to-digital conversion chip with at least 0.1-level precision is arranged, so that accurate measurement and acquisition of signals of the current divider are realized, the heat loss of the current divider can be effectively reduced, and the accuracy of the whole electric energy measurement is improved. Compared with the traditional direct current electric energy metering module, the shunt is internally assembled, the internal space of the device is fully utilized, the shunt is spatially isolated from the multi-core module, and the influence of the temperature rise of the shunt on the circuit work is effectively reduced.)

1. A direct access type direct current electric energy meter is characterized in that,

comprises a shell, a shunt and a multi-core module;

the shell is provided with an accommodating cavity, and an end cover is assembled at the upper end part of the shell;

the shunt is provided with a shunt resistor of 35 mu omega-45 mu omega and used for reducing the heat loss of the shunt, and the shunt is arranged in the assembly space of the shell;

the multi-core module is assembled adjacent to the shunt, is used for realizing the measurement and management of voltage and current, comprises a measurement core and a management core, and a heat dissipation space for heat volatilization is arranged between the multi-core module and the shunt;

the measurement core is equipped with the AD chip, the AD chip is the analog-to-digital conversion chip that has 0.1 level precision at least, realizes the measurement of shunt signal and gathers.

2. A direct access DC power meter according to claim 1,

one interface of the shunt is provided with a sampling end which is used for being communicated with the positive current, and the other interface of the shunt is electrically connected with the AD chip through a transient suppression circuit, an anti-null-shift interference circuit and an anti-aliasing network circuit in sequence.

3. A direct access DC power meter according to claim 2,

the transient suppression circuit is provided with a transient suppression diode TVS and is used for suppressing instant high-energy impact in the circuit;

the zero drift interference resistant circuit is provided with a resistor R55, a resistor R57 and a resistor R59;

the anti-aliasing network circuit is provided with a resistor R56, a resistor R58, a capacitor C70 and a capacitor C71.

4. A direct access DC power meter according to claim 2,

a TMR sensor is arranged adjacent to the current divider and used for collecting the negative current value, realizing electric leakage monitoring comparison and forming a positive and negative bipolar current monitoring structure;

the TMR sensor is electrically connected with the CPU chip through a voltage division filter network circuit;

the voltage division filter network circuit comprises a resistor R49, a resistor R50, a resistor R51, a resistor R52, a resistor R53 and a capacitor C66, and the voltage division filter network circuit is communicated with a B-phase current acquisition channel of a CPU chip to monitor the negative current.

5. A direct access DC power meter according to claim 1,

the metering core also comprises a CPU chip used for managing the AD chip;

the CPU chip is in the model of RN2025 and comprises a direct-current voltage management module, a current sampling module, a direct-current power calculation module, a direct-current electric energy calculation module, a rate management module and a calibration coefficient management module;

the model of the AD chip is ADS131M04, and the AD chip is used for realizing PGA gain amplification of an internal 64-time programmable gain amplifier and realizing 0.1-level precision within a 10000:1 dynamic range.

6. A direct access DC power meter according to claim 1,

the management core is a micro control unit HT6025 which is provided with a communication display module and a data storage module;

the isolation communication between the micro control unit HT6025 and the management core is realized by an isolation-tolerant chip ISO7742 FDW.

7. A direct access DC power meter according to claim 1,

the circuit also comprises a resistance voltage division circuit;

the resistance voltage division circuit comprises a resistor R37, a resistor R38, a resistor R39, a resistor R40, a resistor R41, a resistor R42, a resistor R43, a resistor R44, a resistor R46, a resistor R47, a capacitor C59 and a capacitor C60, and is electrically connected with the AD chip and used for realizing voltage division and sampling of direct-current voltage;

the R37, the resistor R38, the resistor R39, the resistor R40, the resistor R41, the resistor R42, the resistor R43 and the resistor R44 are sequentially connected in series;

the resistor R46 and the capacitor C59 are connected in parallel;

the resistor R47 and the capacitor C60 are connected in parallel.

8. A direct access DC power meter according to any of claims 1 to 7,

the back of the shell is provided with a sliding chute, and a connecting sheet is embedded in the sliding chute;

the two sides of the connecting sheet are bent to form edge bodies which can be embedded into the sliding grooves, and an elliptic connecting hole is formed in the middle of the connecting sheet;

the edge body can slide in the sliding groove to form a guide rail type mounting structure.

9. A direct access type direct current electric energy meter is characterized in that,

the integrated direct current electric energy meter comprises a power supply module, a metering module, a function management module, a storage module, a communication module, a display module, an expansion module and a current divider;

the power supply module is electrically connected with the metering module, the function management module and the communication module respectively;

the metering module is provided with an AD chip, and the AD chip is an analog-to-digital conversion chip at least with 0.1-level precision so as to realize accurate metering and acquisition of signals of the shunt;

the function management module is respectively connected with the metering module, the communication module, the storage module, the display module and the expansion module;

the shunt is provided with a shunt resistance of 35 mu omega-45 mu omega so as to reduce the heat loss of the shunt;

the metering module acquires voltage signals from the positive and negative buses through the divider resistor, acquires current signals through the shunt or/and the zero-flux sensor, and transmits electric quantity parameters subjected to analysis processing to the function management module through the digital isolator through the serial peripheral interface SPI to realize direct-current electric energy metering.

10. A direct access DC power meter according to claim 9,

the function management module displays the acquired electric quantity data on the display module, transmits the data to the background master station through the 485 communication module, and stores the monitored event data in the storage module;

the expansion module is provided with a Bluetooth and micropower wireless transmission module.

Technical Field

The invention relates to a direct access type direct current electric energy meter, and belongs to the technical field of electric energy metering.

Background

Chinese patent (CN 202153235U) discloses a bidirectional dc electric energy meter, which comprises a metering unit, a CPU control unit, a liquid crystal screen, and a power circuit, wherein the metering unit and the CPU control unit are both connected to the power circuit, and further comprises a first RS485 communication circuit and a second RS485 communication circuit both connected to the CPU control unit, and the first RS485 communication circuit and the second RS485 communication circuit are both connected to the power circuit.

This patent is fit for voltage range and wide, is applicable to the measurement of the direct current energy within the rated voltage 750V, and need not the adjustment after the complete machine leaves the factory, is applied to electric automobile charging station, fills electric pile.

The two-way direct current electric energy meter, current sampling relies on external shunt, holistic measurement accuracy is subject to the precision of two parts of electric energy meter and shunt, also need separately to examine in the time of examination, leads to holistic measurement accuracy to be subject to the precision of two parts of electric energy meter and shunt, can cause whole error big partially like this. And the shunt is a resistive sampling element, and the heating loss is large when the current is large. Meanwhile, the use is inconvenient, and the manufacturing and installation costs are high.

If a built-in shunt scheme is adopted, but the existing built-in shunt usually adopts a shunt resistor with large resistance value in order to realize accurate signal acquisition, so that more heat can be generated when large current flows; and because shunt and circuit module are sealed in narrow and small space, can lead to the temperature in the electric energy meter to rise sharply, and then influence the performance of circuit chip, finally influence electric energy meter measurement accuracy.

Disclosure of Invention

Aiming at the defects of the prior art, the invention aims to provide a built-in shunt which adopts a shunt resistor of 35 mu omega-45 mu omega; and meanwhile, an analog-to-digital conversion chip with 0.1-level precision is arranged, so that accurate measurement and acquisition of signals of the current divider are realized, the heat loss of the current divider can be effectively reduced, and the integral electric energy measurement accuracy is improved.

The invention also aims to provide a TMR sensor arranged adjacent to the current divider, which is used for collecting the negative current value and is matched with the current divider capable of collecting the positive current value to form a positive and negative bipolar current monitoring structure; when the electric leakage condition occurs, alarm information can be sent out in time, and therefore the safety and reliability of the direct current power supply system are improved.

In order to achieve one of the above purposes, the technical scheme of the invention is as follows:

a direct access type direct current electric energy meter,

comprises a shell, a shunt and a multi-core module;

the shell is provided with an accommodating cavity, and an end cover is assembled at the upper end part of the shell;

the shunt is provided with a shunt resistor of 35 mu omega-45 mu omega and used for reducing the heat loss of the shunt, and the shunt is arranged in the assembly space of the shell;

the multi-core module is assembled adjacent to the shunt, is used for realizing the measurement and management of voltage and current, comprises a measurement core and a management core, and a heat dissipation space for heat volatilization is arranged between the multi-core module and the shunt;

the measurement core is equipped with the AD chip, the AD chip is the analog-to-digital conversion chip that has 0.1 level precision at least, realizes the accurate measurement of shunt signal and gathers.

Through continuous exploration and test, the shunt with the shunt resistance of 35 mu omega-45 mu omega is arranged, and the analog-to-digital conversion chip with at least 0.1-level precision is arranged, so that accurate measurement and acquisition of signals of the shunt are realized, the heat loss of the shunt can be effectively reduced, and the accuracy of the whole electric energy measurement is improved.

Further, a typical conventional shunt output voltage is 75mV, with its own rated thermal losses equal to the rated current multiplied by 75mV, such as a 300A/75mV specification shunt, with losses at 300A of 22.5W.

When the resistance value of the current divider adopted by the invention is 40 mu omega ohm, the voltage value corresponding to the 300A current is 12mV, and the loss of the current divider is 3.6W at the moment, so that the heat loss is greatly reduced compared with the traditional current divider, and the scheme of the invention is simple, practical and feasible.

Furthermore, because the output voltage signal of the current divider is very small, in order to accurately acquire the output voltage signal of the current divider, an analog-to-digital conversion chip with at least 0.1-level precision is adopted, and the accurate metering acquisition of the current divider signal is realized within a 10000:1 dynamic range.

Furthermore, compared with the traditional direct current electric energy metering module, the shunt is internally assembled, the internal space of the device is fully utilized, the shunt is spatially isolated from the multi-core module, the influence of the temperature rise of the shunt on the circuit work is effectively reduced, and the metering precision of the electric energy meter can be effectively improved.

As a preferable technical measure:

one interface of the shunt is provided with a sampling end which is used for being communicated with the positive current, and the other interface of the shunt is electrically connected with the AD chip through a transient suppression circuit, an anti-null-shift interference circuit and an anti-aliasing network circuit in sequence.

As a preferable technical measure:

the transient suppression circuit is provided with a transient suppression diode TVS and is used for suppressing instant high-energy impact in the circuit;

the zero drift interference resistant circuit is provided with a resistor R55, a resistor R57 and a resistor R59;

the anti-aliasing network circuit is provided with a resistor R56, a resistor R58, a capacitor C70 and a capacitor C71.

In order to achieve the second purpose, the technical scheme of the invention is as follows:

a TMR sensor is arranged adjacent to the current divider and used for collecting the negative current value, realizing electric leakage monitoring comparison and forming a positive and negative bipolar current monitoring structure;

the TMR sensor is electrically connected with the CPU chip through a voltage division filter network circuit;

the voltage division filter network circuit comprises a resistor R49, a resistor R50, a resistor R51, a resistor R52, a resistor R53 and a capacitor C66, and the voltage division filter network circuit is connected with a B-phase current acquisition channel of the CPU chip RN2025 to monitor the negative current.

A TMR sensor is arranged adjacent to a current divider and used for collecting the value of a negative current, and the TMR sensor is matched with the current divider capable of collecting the value of a positive current to form a positive and negative bipolar current monitoring structure; when the electric leakage condition occurs, the alarm information can be sent out in time, so that the safety and reliability of the direct current power supply system are improved, and the scheme is simple and practical.

As a preferable technical measure:

the metering core also comprises a CPU chip used for managing the AD chip;

the CPU chip is in the model of RN2025 and comprises a direct-current voltage management module, a current sampling module, a direct-current power calculation module, a direct-current electric energy calculation module, a rate management module and a calibration coefficient management module;

because the output voltage signal of the current divider is very small, the model of the AD chip is ADS131M04, the AD chip is used for realizing PGA gain amplification of an internal 64-time programmable gain amplifier, and the precision of 0.1 level is realized in a 10000:1 dynamic range.

As a preferable technical measure:

the management core is a micro control unit HT6025 which is provided with a communication display module and a data storage module;

the isolation communication between the micro control unit HT6025 and the management core is realized by an isolation-tolerant chip ISO7742 FDW.

As a preferable technical measure:

the circuit also comprises a resistance voltage division circuit;

the resistance voltage division circuit comprises a resistor R37, a resistor R38, a resistor R39, a resistor R40, a resistor R41, a resistor R42, a resistor R43, a resistor R44, a resistor R46, a resistor R47, a capacitor C59 and a capacitor C60, and is electrically connected with the AD chip and used for realizing voltage division and sampling of direct-current voltage;

the R37, the resistor R38, the resistor R39, the resistor R40, the resistor R41, the resistor R42, the resistor R43 and the resistor R44 are sequentially connected in series;

the resistor R46 and the capacitor C59 are connected in parallel;

the resistor R47 and the capacitor C60 are connected in parallel.

As a preferable technical measure:

the back of the shell is provided with a sliding chute, and a connecting sheet is embedded in the sliding chute;

the two sides of the connecting sheet are bent to form edge bodies which can be embedded into the sliding grooves, and an elliptic connecting hole is formed in the middle of the connecting sheet;

the edge body can slide in the sliding groove to form a guide rail type mounting structure.

The invention adopts a guide rail type design, and is convenient to install and use under various working conditions.

In order to achieve one of the above purposes, the technical scheme of the invention is as follows:

a direct access type direct current electric energy meter is an integrated direct current electric energy meter and comprises a power supply module, a metering module, a function management module, a storage module, a communication module, a display module, an expansion module and a current divider;

the power supply module is electrically connected with the metering module, the function management module and the communication module respectively;

the metering module is provided with an AD chip, and the AD chip is an analog-to-digital conversion chip at least with 0.1-level precision so as to realize accurate metering and acquisition of signals of the shunt;

the function management module is respectively connected with the metering module, the communication module, the storage module, the display module and the expansion module;

the shunt is provided with a shunt resistance of 35 mu omega-45 mu omega so as to reduce the heat loss of the shunt;

the metering module acquires voltage signals from the positive and negative buses through the divider resistor, acquires current signals through the shunt or/and the zero-flux sensor, and transmits electric quantity parameters subjected to analysis processing to the function management module through the digital isolator through the serial peripheral interface SPI to realize direct-current electric energy metering.

As a preferable technical measure:

the function management module displays the acquired electric quantity data on the display module, transmits the data to the background master station through the 485 communication module, and stores the monitored event data in the storage module, so that the data maintenance and recall are facilitated;

the expansion module is provided with a Bluetooth and a micropower wireless transmission module, and realizes more functions such as remote communication and the like.

The display module is a liquid crystal display screen.

The direct current electric energy meter can display the measured data to the working personnel through the liquid crystal display screen, and when the parameters of line voltage, current and the like are abnormal, alarm information is uploaded through the RS485 screen for prompting, so that voltage and current abnormal events can be timely and timely monitored and processed.

Compared with the prior art, the invention has the following beneficial effects:

through continuous exploration and test, the shunt with the shunt resistance of 35 mu omega-45 mu omega is arranged, and the analog-to-digital conversion chip with at least 0.1-level precision is arranged, so that accurate measurement and acquisition of signals of the shunt are realized, the heat loss of the shunt can be effectively reduced, and the accuracy of the whole electric energy measurement is improved.

Furthermore, because the output voltage signal of the current divider is very small, in order to accurately acquire the output voltage signal of the current divider, an analog-to-digital conversion chip with at least 0.1-level precision is adopted, and the accurate metering acquisition of the current divider signal is realized within a 10000:1 dynamic range.

Further, compared with the traditional direct current electric energy metering module, the shunt is internally assembled, the internal space of the device is fully utilized, the shunt is spatially isolated from the multi-core module, and the influence of the temperature rise of the shunt on the circuit work is effectively reduced.

Drawings

FIG. 1 is a schematic view of a diverter according to the present invention;

FIG. 2 is a schematic diagram of the current divider circuit of the present invention;

FIG. 3 is a schematic diagram of the current sampling of the present invention;

FIG. 4 is a voltage sampling schematic of the present invention;

FIG. 5 is a functional block diagram of the DC power meter according to the present invention;

FIG. 6 is a diagram of the general structure of the DC electric energy meter of the present invention (without the end cap assembled);

FIG. 7 is an assembled view of the separator, TMR sensor and housing of the present invention;

fig. 8 is a structural diagram of the back side of the dc power meter of the present invention.

Description of reference numerals:

1. a housing; 2. a communication module; 3. a load identification module; 4. a power quality module; 5. a flow divider; 6. a TMR sensor; 7. connecting sheets; 71. and connecting the holes.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

On the contrary, the invention is intended to cover alternatives, modifications, equivalents and alternatives which may be included within the spirit and scope of the invention as defined by the appended claims. Furthermore, in the following detailed description of the present invention, certain specific details are set forth in order to provide a better understanding of the present invention. It will be apparent to one skilled in the art that the present invention may be practiced without these specific details.

As shown in fig. 1 to 8, a direct access type dc electric energy meter includes a housing 1, a shunt 5, and a multi-core module.

The housing 1 has a receiving cavity, and an end cap is assembled on the upper end portion.

The shunt 5, which is provided with a shunt resistance of 35 mu omega-45 mu omega for reducing heat loss of the shunt 5, is installed in the assembly space of the case 1.

The multicore module, adjacent shunt 5 assembly for realize the measurement and the management of voltage, electric current, it is equipped with the heat dissipation space that is used for the heat to volatilize including measurement core and management core between it and shunt 5.

The measurement core is equipped with the AD chip, the AD chip is the analog-to-digital conversion chip that has 0.1 level precision at least, realizes the accurate measurement of shunt 5 signal and gathers.

Through continuous exploration and test, the shunt 5 with the shunt resistance of 35 mu omega-45 mu omega is arranged, and the analog-to-digital conversion chip with at least 0.1-level precision is arranged, so that the accurate measurement and acquisition of signals of the shunt 5 are realized, the heat loss of the shunt 5 can be effectively reduced, and the accuracy of the whole electric energy measurement is improved.

Further, a typical conventional shunt 5 has an output voltage of 75mV, its own rated heat loss is equal to the rated current multiplied by 75mV, for example, a 300A/75mV specification shunt 5, with a loss of 22.5W at 300A.

When the resistance value of the shunt 5 adopted by the invention is 40 mu omega ohm, the voltage value corresponding to the 300A current is 12mV, and the loss of the shunt 5 is 3.6W at the moment, so that the heat loss is greatly reduced compared with the traditional shunt 5, therefore, the scheme of the invention is simple, practical and feasible.

Furthermore, because the output voltage signal of the current divider 5 is very small, in order to accurately acquire the output voltage signal of the current divider 5, an analog-to-digital conversion chip with at least 0.1-level precision is adopted, and the accurate measurement and acquisition of the signal of the current divider 5 are realized within a 10000:1 dynamic range.

A preferred embodiment of the present invention:

a direct access type direct current electric energy meter adopts a multi-core modularized design scheme and is divided into a metering core and a management core. The metering core is realized by a capacitance CPU chip RN2025 and an AD chip ADS131M04, and the functions of the management core are completed by HT6025, including functions of communication display, data storage and the like. The isolation communication between the metering core and the management core is realized through an isolation-tolerant chip ISO7742 FDW.

The main functions of the metering core comprise a direct-current voltage module, a current sampling module, a direct-current power calculating module, a direct-current electric energy calculating module, a rate management module, a calibration coefficient management module and the like. The direct current load characteristic real-time analysis system can exchange direct current electric quantity data with a management core in real time, and an SPI (serial peripheral interface) can output direct current AD sampling original data in real time to be used for analyzing direct current load characteristics by an expansion module.

The function management module realizes the function requirements of the electric energy meter such as key pressing, display, communication and the like, and can be upgraded and updated through software so as to adapt to the requirement of new functions.

The invention also has very strong expandability, and the expansion module can select modules with different functions according to actual requirements, supports pluggable and flexibly selects and matches device functions to adapt to different engineering requirements. The expansion module can read the sampled voltage and current AD data in real time through the SPI bus interface, and subsequent load characteristic analysis is facilitated.

The invention adopts the mode that the function management module is active and other modules are passive. After the function management module is configured with modules such as metering modules, each module starts to operate independently, the function management module asks for electric energy data from the metering module at fixed intervals, and monitors the operation states of other modules. Once the metering modules and the like generate errors, the function management module sends an instruction to reset the abnormal module.

The invention adopts a positive and negative bipolar current monitoring mode, wherein the positive current adopts a shunt 5 sampling scheme, and the negative current adopts a TM R sensor 6 scheme. The positive electrode current is used as the electric energy metering current value, and the negative electrode current value is used as the electric leakage monitoring comparison value.

The conventional shunt 5 has an output voltage of 75mV and its own rated heat loss equal to the rated current multiplied by 75mV, for example a 300A/75mV specification shunt 5 with a loss of 22.5W at 300A.

The resistance value of the shunt 5 adopted by the invention is 40 mu omega ohm, namely the voltage value at 300A is 12mV, and the loss of the shunt 5 is 3.6W, so that the heat loss is greatly reduced compared with the traditional shunt 5, and the reference figure 1 shows that.

Because the output voltage signal of the current divider 5 is very small, the AD chip ADS131M04 is adopted to realize signal acquisition, the PGA gain amplification of the internal 64-time programmable gain amplifier can be realized, the 0.1-level precision can be realized within the 10000:1 dynamic range, and the circuit principle is shown in figure 2.

The voltage value of mV output by the shunt 5 is protected by a transient suppression diode TVS (transient suppression diode) of V15, passes through an anti-null-drift interference circuit consisting of a resistor R55, a resistor R57 and a resistor R59, and enters an AD chip ADS131M04 through an anti-aliasing network consisting of a resistor R56, a resistor R58, a capacitor C70 and a capacitor C71.

The transient suppression diode TVS is a semiconductor device having a surge absorption capability, and its response time is very fast, reaching a sub-nanosecond level, so that once a circuit receives an instantaneous high energy impact, it can suppress the energy, and by absorbing an instantaneous large current and high voltage from the circuit, the final result is to protect the following devices or circuits.

The output rated value of the negative pole current TMR sensor is 4V, and the output rated value enters a B-phase current acquisition channel of the CPU chip RN2025 for monitoring through a voltage division filter network consisting of a resistor R49, a resistor R50, a resistor R51, a resistor R52, a resistor R53 and a capacitor C66, and the monitoring is carried out, referring to fig. 3.

The voltage sampling embodiment of the invention:

the invention adopts a resistance voltage division mode to realize direct current voltage sampling, and the principle is shown in figure 4:

after the voltage of the direct current bus is divided to about 100mV through a resistor, the voltage enters an AD chip ADS131M04 for voltage calculation.

After the voltage and the current are collected by the AD chip ADS131M04, the sampled data are transmitted to the CPU chip RN2025 through the serial peripheral interface SPI bus, and then voltage, current, power quantization and direct current electric energy metering are carried out. The electric energy calculation method adopts an instantaneous power integration method for accumulation.

Compared with the traditional direct current electric energy metering module, the direct current electric energy metering module has the advantages that a novel structural design is adopted, the size of the direct current electric energy metering module is increased, and the direct current electric energy metering module is suitable for built-in assembly of the shunt 5. The wiring of the device adopts a through type wiring, the internal space of the device is fully utilized, the shunt 5 is isolated from the circuit design in space, and the influence of the temperature rise of the shunt 5 on the circuit work is effectively reduced. The structure of the shell 1 adopts a guide rail type design, and is convenient to install and use under various working conditions.

According to the direct current electric energy meter, the shunt 5 and the multi-core module are assembled together, so that the use difficulty and the installation cost are effectively reduced, the product maintainability is improved, the loss of a direct current line is reduced, the influence of a separation system on the metering accuracy is eliminated, and the electric energy metering precision is greatly improved.

The direct current electric energy meter is provided with the power failure meter reading battery and the clock battery for power supply, can monitor direct current voltage and current in real time, can accurately store, record and monitor electric energy data, and is simple in power supply and convenient to use.

The direct current electric energy meter can monitor the currents of the positive pole and the negative pole, can monitor the current inequality in time when electric leakage occurs, triggers a fault event, and actively reports the fault event to a system, thereby greatly improving the reliability of power utilization.

The best embodiment of the invention is as follows:

a direct access type direct current electric energy meter is an integrated direct current electric energy meter and comprises a power supply module, a metering module, a function management module, a storage module, a communication module 2, a display module, an expansion module, a load identification module 3 and an electric energy quality module 4.

The metering module, the function management module and the communication module 2 are all connected with the power supply module, and the function management module is respectively connected with the metering module, the communication module 2, the storage module, the display module and the expansion module.

One end of the positive and negative copper bars is connected to the low-voltage side of the direct-current power distribution network conversion system, and the other end of the positive and negative copper bars is connected to a direct-current power load. The metering module acquires voltage signals from the positive and negative buses through the divider resistor, acquires current signals in a mode of the current divider 5 or the zero-flux sensor, and transmits electric quantity parameters subjected to analysis processing to the function management module through the digital isolator through the SPI. The function management module displays the collected electric quantity data on the liquid crystal panel, transmits the data to the background master station through the 485 communication module 2, and stores the monitored event data in the storage module, so that the data maintenance and the recall are facilitated. The expansion module can be matched with functional modules such as Bluetooth, micropower wireless and the like according to actual needs, and more functions such as remote communication and the like are realized.

The invention uses the zero-flux current sensor to finish the sampling of the direct current, thereby further reducing the loss of the direct current line.

The zero-flux current sensor is designed based on a magnetic sensing technology and a closed-loop working principle, has the characteristics of high precision and low power consumption, does not generate heat and has good temperature stability and no influence on a metering circuit compared with the manganin shunt 5. Meanwhile, primary and secondary isolation measurement can be carried out, the method has the characteristics of high response speed, good linearity and large measurement current range, and the accuracy of the direct current electric energy meter can be effectively improved.

The back of the shell is provided with a sliding chute, and a connecting sheet 7 is embedded in the sliding chute;

two sides of the connecting sheet 7 are bent to form edge bodies which can be embedded into the sliding grooves, and an elliptic connecting hole 71 is formed in the middle of the connecting sheet;

the edge body can slide in the sliding groove to form a guide rail type mounting structure.

The invention adopts a guide rail type design, thereby being convenient for installation and use under various working condition environments; meanwhile, the wiring adopts a vertically through type wiring, the panel is provided with a liquid crystal display and display following key, and the flip cover can replace an extension module.

Finally, it should be noted that: the above embodiments are only for illustrating the technical solutions of the present invention and not for limiting the same, and although the present invention is described in detail with reference to the above embodiments, those of ordinary skill in the art should understand that: modifications and equivalents may be made to the embodiments of the invention without departing from the spirit and scope of the invention, which is to be covered by the claims.