阅读说明：本技术 计量电路、多通道计量电路及计量设备 (Metering circuit, multichannel metering circuit and metering equipment ) 是由 周为 胡环 王卫华 刘旭杰 王建忠 于 2021-08-17 设计创作，主要内容包括：本发明公开了一种计量电路、多通道计量电路及计量设备,所述计量电路,包括：第一电压采样模块、第二电压采样模块、电流采样模块和计量模块,计量模块的第一端与第一电压采样模块的输出端连接,计量模块的第二端与第二电压采样模块的输出端连接,计量模块的第三端与电流采样模块的输出端连接；第一电压采样模块、第二电压采样模块,用于对电压信号进行采样,以得到并输出电压信号；电流采样模块,用于对电流信号进行采样,以得到并输出电流信号；计量模块,用于通过第一电压采样模块或第二电压采样模块得到电压信号,并根据所述电压信号和电流信号进行电能计量。本发明减少了两路电压信号输入的计量回路中的信号损失,提升了计量准确性。(The invention discloses a metering circuit, a multi-channel metering circuit and a metering device, wherein the metering circuit comprises: the device comprises a first voltage sampling module, a second voltage sampling module, a current sampling module and a metering module, wherein the first end of the metering module is connected with the output end of the first voltage sampling module, the second end of the metering module is connected with the output end of the second voltage sampling module, and the third end of the metering module is connected with the output end of the current sampling module; the first voltage sampling module and the second voltage sampling module are used for sampling the voltage signals to obtain and output voltage signals; the current sampling module is used for sampling the current signal to obtain and output the current signal; and the metering module is used for obtaining a voltage signal through the first voltage sampling module or the second voltage sampling module and metering electric energy according to the voltage signal and the current signal. The invention reduces the signal loss in the metering loop of two paths of voltage signal input and improves the metering accuracy.)

1. A metering circuit, comprising: the device comprises a first voltage sampling module, a second voltage sampling module, a current sampling module and a metering module, wherein a first end of the metering module is connected with an output end of the first voltage sampling module, a second end of the metering module is connected with an output end of the second voltage sampling module, and a third end of the metering module is connected with an output end of the current sampling module;

the first voltage sampling module and the second voltage sampling module are used for sampling the voltage signals to obtain and output voltage signals;

the current sampling module is used for sampling the current signal to obtain and output the current signal;

the metering module is used for obtaining a voltage signal through the first voltage sampling module or the second voltage sampling module;

and the metering module is also used for metering electric energy according to the voltage signal and the current signal.

2. The metering circuit of claim 1, wherein the metering module comprises a voltage converting unit, a current converting unit and a metering unit, wherein an input end of the voltage converting unit is connected with an output end of the first voltage sampling module and an output end of the second voltage sampling module, an input end of the current converting unit is connected with an output end of the current sampling module, and an output end of the voltage converting unit and an output end of the current converting unit are respectively connected with the metering unit;

the metering unit is used for obtaining a voltage signal through the first voltage sampling module or the second voltage sampling module;

and the metering unit is also used for metering electric energy according to the voltage signal and the current signal.

3. The metering circuit of claim 2, wherein the voltage converting unit includes a first voltage converting unit and a second voltage converting unit, an output terminal of the first voltage converting unit and an output terminal of the second voltage converting unit are respectively connected to the metering unit,

the first voltage conversion unit and the second voltage conversion unit respectively comprise an A-phase voltage conversion unit, a B-phase voltage conversion unit and a C-phase voltage conversion unit,

the input ends of the A phase voltage conversion unit, the B phase voltage conversion unit and the C phase voltage conversion unit of the first voltage conversion unit are connected with the output end of the first voltage sampling unit, the output ends of the A phase voltage conversion unit, the B phase voltage conversion unit and the C phase voltage conversion unit of the first voltage conversion unit are connected with the metering unit,

the input ends of the A-phase voltage conversion unit, the B-phase voltage conversion unit and the C-phase voltage conversion unit of the second voltage conversion unit are connected with the output end of the second voltage sampling unit, and the output ends of the A-phase voltage conversion unit, the B-phase voltage conversion unit and the C-phase voltage conversion unit of the second voltage conversion unit are connected with the metering unit.

4. The metering circuit of claim 2 wherein the current converting unit comprises an a-phase current signal converter, a B-phase current signal converter, and a C-phase current signal converter, an input of the a-phase current signal converter, an input of the B-phase current signal converter, and an input of the C-phase current signal converter are connected to an output of the current sampling module, and an output of the a-phase current signal converter, an output of the B-phase current signal converter, and an output of the C-phase current signal converter are connected to the metering unit, respectively.

5. The metering circuit of claim 1 wherein the first and second voltage sampling modules comprise an a-phase voltage sampling unit, a B-phase voltage sampling unit, and a C-phase voltage sampling unit, respectively;

the input ends of an A phase voltage sampling unit, a B phase voltage sampling unit and a C phase voltage sampling unit of the first voltage sampling module are the input ends of the first voltage sampling module, the output ends of the A phase voltage sampling unit, the B phase voltage sampling unit and the C phase voltage sampling unit of the first voltage sampling module are the output ends of the first voltage sampling module,

the input ends of an A phase voltage sampling unit, a B phase voltage sampling unit and a C phase voltage sampling unit of the second voltage sampling module are the input ends of the second voltage sampling module, and the output ends of the A phase voltage sampling unit, the B phase voltage sampling unit and the C phase voltage sampling unit of the second voltage sampling module are the output ends of the second voltage sampling module.

6. The metering circuit of claim 1 wherein the current sampling module comprises an A-phase current sampling unit, a B-phase current sampling unit, and a C-phase current sampling unit,

the input ends of the A-phase current sampling unit, the B-phase current sampling unit and the C-phase current sampling unit are the input ends of the current sampling module, and the output ends of the A-phase current sampling unit, the B-phase current sampling unit and the C-phase current sampling unit are the output ends of the current sampling module.

7. A multi-channel metering circuit is characterized in that the multi-channel metering circuit comprises a control circuit and at least one metering circuit, the output end of the metering circuit is connected with the control circuit,

the metering circuit configured as the metering circuit of any one of claims 1-6,

the control circuit is used for sending out a metering selection signal so that the metering module can obtain a voltage signal through the first voltage sampling module or the second voltage sampling module.

8. The multi-channel metering circuit of claim 7 further comprising a communication module, the communication module coupled to the control circuit,

the communication module is used for receiving the metering selection signal and transmitting the metering selection signal to the control circuit so as to control the metering module to perform corresponding electric energy metering.

9. The multi-channel metering circuit of claim 8, further comprising a power conversion module, wherein an input of the power conversion module is connected to a first power source, a first output of the power conversion module outputs a second power source, and a second output of the power conversion module outputs a third power source.

10. A metrology apparatus, characterized in that it comprises:

a metering circuit configured as the metering circuit of any one of claims 1-6;

or, a multi-channel metering circuit configured as a multi-channel metering circuit as claimed in any one of claims 7-9.

Technical Field

The invention relates to the field of power equipment, in particular to a metering circuit, a multi-channel metering circuit and metering equipment.

Background

The station terminal is a common distribution network device at present, and is commonly used in a ring main unit and an opening and closing station in a cable network. The power distribution metering equipment for the station terminal is used for counting the power consumption provided by the station terminal to the next-level terminal, and management of power distribution network line loss is facilitated.

The power distribution metering equipment of the station terminal generally needs to support 2-circuit three-phase voltage signal input and 4-circuit, 6-circuit or 8-circuit three-phase current input, measure the input voltage and current signals, measure the electric energy and upload the measured electric energy to the station terminal main station.

At present, an electric energy metering mode is mainly implemented by using a metering chip, the three-phase metering chip generally only supports metering of one path of three-phase voltage and one path of three-phase current, and in order to solve the problem that a single-path metering loop can support input of two paths of three-phase voltage signals, a common solution is to switch voltage signals entering the metering chip through an analog switch or a small signal relay, and for metering equipment supporting 8 paths of current signals, 8 groups of three-phase voltage channels are needed, and 24 groups of two-selected analog switches or a single-pole double-throw signal relay are needed.

Disclosure of Invention

The invention mainly aims to provide a metering circuit, a multi-channel metering circuit and metering equipment, and aims to solve the problem of serious signal loss in a single-channel metering loop with two-channel voltage signal input and improve the metering accuracy.

To achieve the above object, the present invention provides a metering circuit, comprising: the device comprises a first voltage sampling module, a second voltage sampling module, a current sampling module and a metering module, wherein a first end of the metering module is connected with an output end of the first voltage sampling module, a second end of the metering module is connected with an output end of the second voltage sampling module, and a third end of the metering module is connected with an output end of the current sampling module;

the first voltage sampling module and the second voltage sampling module are used for sampling the voltage signals to obtain and output voltage signals;

the current sampling module is used for sampling the current signal to obtain and output the current signal;

the metering module is used for obtaining a voltage signal through the first voltage sampling module or the second voltage sampling module;

and the metering module is also used for metering electric energy according to the voltage signal and the current signal.

Optionally, the metering module includes a voltage conversion unit, a current conversion unit and a metering unit, an input end of the voltage conversion unit is connected to an output end of the first voltage sampling module and an output end of the second voltage sampling module, an input end of the current conversion unit is connected to an output end of the current sampling module, and an output end of the voltage conversion unit and an output end of the current conversion unit are respectively connected to the metering unit;

the metering unit is used for obtaining a voltage signal through the first voltage sampling module or the second voltage sampling module;

and the metering unit is also used for metering electric energy according to the voltage signal and the current signal.

Optionally, the voltage conversion unit includes a first voltage conversion unit and a second voltage conversion unit, an output end of the first voltage conversion unit and an output end of the second voltage conversion unit are respectively connected to the metering unit,

the first voltage conversion unit and the second voltage conversion unit respectively comprise an A-phase voltage conversion unit, a B-phase voltage conversion unit and a C-phase voltage conversion unit,

the input ends of the A phase voltage conversion unit, the B phase voltage conversion unit and the C phase voltage conversion unit of the first voltage conversion unit are connected with the output end of the first voltage sampling unit, the output ends of the A phase voltage conversion unit, the B phase voltage conversion unit and the C phase voltage conversion unit of the first voltage conversion unit are connected with the metering unit,

the input ends of the A-phase voltage conversion unit, the B-phase voltage conversion unit and the C-phase voltage conversion unit of the second voltage conversion unit are connected with the output end of the second voltage sampling unit, and the output ends of the A-phase voltage conversion unit, the B-phase voltage conversion unit and the C-phase voltage conversion unit of the second voltage conversion unit are connected with the metering unit.

Optionally, the current converting unit includes an a-phase current signal converter, a B-phase current signal converter, and a C-phase current signal converter, an input end of the a-phase current signal converter, an input end of the B-phase current signal converter, and an input end of the C-phase current signal converter are connected to an output end of the current sampling module, and an output end of the a-phase current signal converter, an output end of the B-phase current signal converter, and an output end of the C-phase current signal converter are respectively connected to the metering unit.

Optionally, the first voltage sampling module and the second voltage sampling module respectively include an a-phase voltage sampling unit, a B-phase voltage sampling unit, and a C-phase voltage sampling unit;

the input ends of an A phase voltage sampling unit, a B phase voltage sampling unit and a C phase voltage sampling unit of the first voltage sampling module are the input ends of the first voltage sampling module, the output ends of the A phase voltage sampling unit, the B phase voltage sampling unit and the C phase voltage sampling unit of the first voltage sampling module are the output ends of the first voltage sampling module,

the input ends of an A phase voltage sampling unit, a B phase voltage sampling unit and a C phase voltage sampling unit of the second voltage sampling module are the input ends of the second voltage sampling module, and the output ends of the A phase voltage sampling unit, the B phase voltage sampling unit and the C phase voltage sampling unit of the second voltage sampling module are the output ends of the second voltage sampling module.

Optionally, the current sampling module comprises a phase A current sampling unit, a phase B current sampling unit and a phase C current sampling unit,

the input ends of the A-phase current sampling unit, the B-phase current sampling unit and the C-phase current sampling unit are the input ends of the current sampling module, and the output ends of the A-phase current sampling unit, the B-phase current sampling unit and the C-phase current sampling unit are the output ends of the current sampling module.

In addition, to achieve the above object, the present invention provides a multi-channel metering circuit, which is characterized in that the multi-channel metering circuit comprises a control circuit and at least one metering circuit, the output end of the metering circuit is connected with the control circuit,

the metering circuit is configured as the metering circuit described above,

the control circuit is used for sending out a metering selection signal so that the metering module can obtain a voltage signal through the first voltage sampling module or the second voltage sampling module.

Optionally, the multi-channel metering circuit further comprises a communication module, the communication module is connected with the control circuit,

the communication module is used for receiving the metering selection signal and transmitting the metering selection signal to the control circuit so as to control the metering module to perform corresponding electric energy metering.

Optionally, the multichannel metering circuit further includes a power conversion module, an input end of the power conversion module is connected to the first power supply, a first output end of the power conversion module outputs the second power supply, and a second output end of the power conversion module outputs the third power supply.

Further, to achieve the above object, the present invention also provides a metering apparatus comprising:

a metering circuit configured as described above;

or, a multi-channel metering circuit configured as a multi-channel metering circuit as described above.

The invention discloses a metering circuit, comprising: the device comprises a first voltage sampling module, a second voltage sampling module, a current sampling module and a metering module, wherein a first end of the metering module is connected with an output end of the first voltage sampling module, a second end of the metering module is connected with an output end of the second voltage sampling module, and a third end of the metering module is connected with an output end of the current sampling module; the first voltage sampling module and the second voltage sampling module are used for sampling the voltage signals to obtain and output voltage signals; the current sampling module is used for sampling the current signal to obtain and output the current signal; the metering module is used for obtaining a voltage signal through the first voltage sampling module or the second voltage sampling module; and the metering module is also used for metering electric energy according to the voltage signal and the current signal. The software program is arranged in the metering module in advance, so that the software control metering module selects the voltage signal input by the first voltage sampling module or the voltage signal input by the second voltage sampling module, devices such as an analog switch or a relay are not needed in a single-circuit metering loop with two-circuit voltage signal input, the signal loss in the metering loop with two-circuit voltage signal input is reduced, and the metering accuracy is improved.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the structures shown in the drawings without creative efforts.

FIG. 1 is a block diagram of a metering circuit according to an embodiment of the present invention;

FIG. 2 is a schematic diagram of a metering module according to an embodiment of the present invention;

FIG. 3 is a detailed diagram of a metering module in an embodiment of the metering circuit of the present invention;

FIG. 4 is a detailed diagram of a metering module in another embodiment of the metering circuit of the present invention;

FIG. 5 is a schematic diagram of a voltage sampling module according to an embodiment of the metering circuit of the present invention;

FIG. 6 is a detailed diagram of a voltage sampling module according to an embodiment of the metering circuit of the present invention;

FIG. 7 is a schematic diagram of a current sampling module according to an embodiment of the metering circuit of the present invention;

FIG. 8 is a detailed diagram of a current sampling module according to an embodiment of the metering circuit of the present invention;

FIG. 9 is a block diagram of a multi-channel metering circuit according to an embodiment of the present invention;

FIG. 10 is a block diagram of a multi-channel metering circuit according to an embodiment of the present invention;

FIG. 11 is a block diagram of another embodiment of a multi-channel metering circuit of the present invention.

The implementation, functional features and advantages of the objects of the present invention will be further explained with reference to the accompanying drawings.

The reference numbers illustrate:

reference numerals	Name (R)	Reference numerals	Name (R)
				10	First voltage sampling module	421	B-phase current signal converter
20	Second voltage sampling module	422	C-phase current signal converter
				30	Current sampling module	101	A phase voltage sampling unit
40	Metering module	102	B-phase voltage sampling unit
				41	Voltage conversion unit	103	C-phase voltage sampling unit
42	Current conversion unit	301	A-phase current sampling unit
				43	Metering unit	302	B-phase current sampling unit
410	First voltage conversion unit	303	C-phase current sampling unit
				411	Second voltage conversion unit	50	Control module in multi-channel metering circuit
412	A-phase voltage conversion unit	60	Metering circuit in multi-channel metering circuit
				413	B-phase voltage conversion unit	70	Communication module
414	C-phase voltage conversion unit	80	Power supply conversion module
				420	A-phase current signal converter

Detailed Description

It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

It should be noted that all the directional indicators (such as up, down, left, right, front, and rear … …) in the embodiment of the present invention are only used to explain the relative position relationship between the components, the movement situation, etc. in a specific posture (as shown in the drawing), and if the specific posture is changed, the directional indicator is changed accordingly.

In addition, the descriptions related to "first", "second", etc. in the present invention are for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In addition, technical solutions between various embodiments may be combined with each other, but must be realized by a person skilled in the art, and when the technical solutions are contradictory or cannot be realized, such a combination should not be considered to exist, and is not within the protection scope of the present invention.

The station terminal is a common distribution network device, and the distribution metering equipment of the station terminal generally needs to support the input of main and standby three-phase voltage signals and the input of 4, 6 or 8 three-phase currents, measure the input voltage and current signals and meter electric energy, and upload the measured signals to the station terminal main station.

At present, in field wiring, one group of voltage signals in two groups of voltage signals corresponds to 2-path, 3-path, 4-path or even directly matches 8-path current signal output; the two groups of voltage signals correspond to 4-path, 6-path or 8-path signal output. Due to the fact that field wiring is complex or other power distribution wiring requirements exist, one path of voltage does not have one-to-one correspondence with corresponding current output, and therefore input three-phase voltage signals and three-phase current signals need to be matched one by one according to field conditions.

Taking two groups of three-phase voltages and 8-circuit three-phase current input as an example, one path of three-phase current may correspond to a first three-phase voltage or a second three-phase voltage, and so on, and the arrangement and combination modes are more. The complexity of wiring and circuit design of the power distribution metering equipment is increased. At present, a conventional electric energy metering mode mainly uses a metering chip, and the three-phase metering chip generally only supports metering of one three-phase voltage and one three-phase current, such as a common metering chip HT 7038. In order to solve the problem that a single-circuit metering loop can support the input of two groups of three-phase voltage signals, a common solution is to switch the voltage signals entering a metering chip through an analog switch or a small signal relay, and for the specification of supporting 8 circuits of current signals, 8 groups of three-phase voltage channels are needed, and 24 circuits of analog switches or single-pole double-throw signal relays are selected from one another totally, so that the scheme undoubtedly increases the complexity of product design and the risk of signal loss.

Based on the phenomenon, the invention provides a metering circuit, a multi-channel metering circuit and a metering device, so that the voltage signal entering a metering chip is switched without using an analog switch or a small signal relay, the signal loss is reduced, and the metering accuracy is improved.

Referring to fig. 1, the present invention provides a metering circuit, which in one embodiment comprises: the voltage measuring device comprises a first voltage sampling module 10, a second voltage sampling module 20, a current sampling module 30 and a metering module 40, wherein a first end of the metering module 40 is connected with an output end of the first voltage sampling module 10, a second end of the metering module 40 is connected with an output end of the second voltage sampling module 20, and a third end of the metering module 40 is connected with an output end of the current sampling module 30;

the first voltage sampling module 10 and the second voltage sampling module 20 are used for sampling the voltage signal to obtain and output a voltage signal;

the current sampling module 30 is configured to sample a current signal to obtain and output the current signal;

the metering module 40 is configured to obtain a voltage signal through the first voltage sampling module 10 or the second voltage sampling module 20;

the metering module 40 is further configured to perform electric energy metering according to the voltage signal and the current signal.

The metering module 40 is configured to obtain a voltage signal through the first voltage sampling module 10 or the second voltage sampling module 20, where the first voltage sampling module 10 samples and outputs a first voltage signal, the second voltage sampling module 20 samples and outputs a second voltage signal, and the metering module 40 selects one of the first voltage signal and the second voltage signal as a voltage signal to be calculated with the current signal through software setting.

In this embodiment, the metering circuit 40 is correspondingly connected to a current signal input and two voltage signal inputs, which are respectively a current signal output by the current sampling module 30, a voltage signal output by the first voltage sampling module 10, and a voltage signal output by the second voltage sampling module 20. Specifically, the first voltage sampling module 10 and the second voltage sampling module 20 are respectively used for connecting a main circuit voltage and a standby circuit voltage, and it can be understood that only one circuit of the main and standby voltages is supplied with power at the same time, so that only one circuit of voltage signals of the supplied power needs to be measured, that is, the measuring module 40 only needs to measure one circuit of signals of the sampled power supply voltages in the first voltage sampling module 10 and the second voltage sampling module 20. The specific path is determined in the process of field wiring and configuration during power supply, so that an operation program is preset in the metering module 40, the metering module 40 selects the voltage signal output by the corresponding voltage sampling module, and the voltage signal and the current signal are calculated, and then electric energy metering is realized.

The metering circuit may further include a control module to which the metering module 40 may be connected, a switch module connected to the control module, and/or a communication module. When the field wiring or configuration error occurs and the program in the metering module 40 is preset, the program can be switched and selected through the switch module, so that the control module sends a switching signal to the metering module 40, and the metering module 40 switches the selected voltage sampling module; the switching signal sent by the remote control terminal can be received through the communication module, so that the control circuit receives and sends a selection signal to the metering module 40, and the metering module 40 selects the voltage signals input by the two voltage sampling modules.

This scheme is through the input preset program in measurement module 40 to realize that software control's mode selects the voltage signal of input, no longer need the access of components and parts such as analog switch or single-pole double-throw signal relay of alternative, both can reduce the signal loss in the transmission course, improve the measurement degree of accuracy, can reduce the complexity of wiring again, alleviate the working strength of wiring, and, under the condition that the misconnection appears, can realize by long-range direct switch-over, do not need artifically to confirm to the scene, reduce the cost of labor.

In this embodiment, the metering circuit includes: the device comprises a first voltage sampling module, a second voltage sampling module, a current sampling module and a metering module, wherein a first end of the metering module is connected with an output end of the first voltage sampling module, a second end of the metering module is connected with an output end of the second voltage sampling module, and a third end of the metering module is connected with an output end of the current sampling module; the first voltage sampling module and the second voltage sampling module are used for sampling the voltage signals to obtain and output voltage signals; the current sampling module is used for sampling the current signal to obtain and output the current signal; the metering module is used for obtaining a voltage signal through the first voltage sampling module or the second voltage sampling module; and the metering module is also used for metering electric energy according to the voltage signal and the current signal. The software program is written in the metering unit in advance, so that the software controls the metering unit to select the voltage signal input by the first voltage sampling unit or the voltage signal input by the second voltage sampling unit, and a single-circuit metering loop with two-circuit voltage signal input does not need devices such as an analog switch or a relay and the like, so that the signal loss in the metering loop with two-circuit voltage signal input is reduced, and the metering accuracy is improved.

Further, referring to fig. 2, the metering module 40 includes a voltage converting unit 41, a current converting unit 42 and a metering unit 43, an input terminal of the voltage converting unit 41 is connected to an output terminal of the first voltage sampling module 10 and an output terminal of the second voltage sampling module 20, an input terminal of the current converting unit 42 is connected to an output terminal of the current sampling module 30, and an output terminal of the voltage converting unit 41 and an output terminal of the current converting unit 42 are respectively connected to the metering unit 43;

the metering unit 43 is configured to obtain a voltage signal through the first voltage sampling module 10 or the second voltage sampling module 20;

the metering unit 43 is further configured to perform electric energy metering according to the voltage signal and the current signal.

The voltage conversion unit 41 is configured to isolate a voltage signal and perform analog-to-digital signal conversion; the current conversion unit 42 is used for performing analog-to-digital signal conversion on the current signal; the metering unit 43 includes a System On Chip (SOC) having a communication interface, the communication interface may be used for communicating with the control module, for example, a serial port, and the SOC may store and operate a program to realize selection of calculation of the voltage signal and the current signal corresponding to the first voltage sampling module 10 or calculation of the voltage signal and the current signal corresponding to the second voltage sampling module 20. In response to the configuration command, the metering unit 43 allows the metering unit 43 to select the metering in the two sets of voltage signals by the programmed configuration inside the SOC.

Further, referring to fig. 3, the voltage converting unit 41 includes a first voltage converting unit 410 and a second voltage converting unit 411, an output terminal of the first voltage converting unit 410 and an output terminal of the second voltage converting unit 411 are respectively connected to the metering unit 43,

the first voltage converting unit 410 and the second voltage converting unit 411 include an a-phase voltage converting unit 412, a B-phase voltage converting unit 413, and a C-phase voltage converting unit 414,

the input terminals of the a-phase voltage converting unit 412, the B-phase voltage converting unit 413 and the C-phase voltage converting unit 414 of the first voltage converting unit 410 are connected to the output terminal of the first voltage sampling unit 10, the output terminals of the a-phase voltage converting unit 412, the B-phase voltage converting unit 413 and the C-phase voltage converting unit 414 of the first voltage converting unit 410 are connected to the metering unit 43,

the input terminals of the a-phase voltage converting unit 412, the B-phase voltage converting unit 413, and the C-phase voltage converting unit 414 of the second voltage converting unit 411 are connected to the output terminal of the second voltage sampling unit 20, and the output terminals of the a-phase voltage converting unit 412, the B-phase voltage converting unit 413, and the C-phase voltage converting unit 414 of the second voltage converting unit 411 are connected to the metering unit 43.

Specifically, the a-phase voltage converting unit 412, the B-phase voltage converting unit 413, and the C-phase voltage converting unit 414 respectively include a signal isolating unit and a voltage signal converting unit,

the input end of the signal isolation unit of the first voltage conversion unit 410 is connected to the output end of the first voltage sampling module 10, the input end of the signal isolation module of the second voltage conversion unit 411 is connected to the output end of the second voltage sampling module 20, the output end of the signal isolation unit is connected to the input end of the voltage signal conversion module, and the output end of the voltage signal conversion module is connected to the input end of the metering unit 43.

It should be noted that, the problem of crosstalk between the sampling modules to the buses in the a, B, and C phases occurs, and the too long weak voltage signal bus is inevitably susceptible to external interference, thereby affecting the metering.

Referring to fig. 4, the voltage signal conversion unit may include an SAR ADC, and in data obtained by processing the SAR ADC, software filtering is generally performed on a voltage reference signal, that is, a software dc removal algorithm is performed to remove the voltage signal reference by software, where the method is to take an average value of a last cycle sampled by the SAR ADC as a value of the software filtering; the metering unit filters the reference value and then performs electric quantity metering with the current signal. Thereby allowing for greater accuracy in the metrology signal. At present, a voltage sampling mode can be a differential input ADC circuit, and the differential input ADC circuit has the advantage of strong common-mode interference resistance, but the differential input occupies one IO pin more than the single-ended input, the hardware circuit design occupies more resources, the SAR ADC input of the single-ended input saves the IO hardware resources of a chip than the circuit of the differential input, and the common-mode signal interference can be overcome through the optimization and the processing of the circuit design.

The signal isolation unit can include the voltage follower, need explain that, the voltage signal of voltage sampling module sampling passes through three-phase voltage signal bus transmission to metering module, and when voltage signal bus was walked the line for circuit layout longer, the signal line was longer more, and circuit impedance is big more, and is big more to the interference of signal, also introduces external disturbance easily simultaneously, and a plurality of SAR ADC's parallelly connected sample also can cause voltage sampling signal's mutual interference. In the embodiment, the voltage follower for signal isolation is added in front of the SAR ADC, so that the input impedance of voltage signal sampling is greatly increased, the output impedance of signals entering the SAR ADC is reduced, the problems of signal attenuation and interference caused by signal line length are solved, and the mutual crosstalk of the sampling modules to buses on the A phase, the B phase and the C phase is favorably reduced.

The first voltage conversion unit 410 and the second voltage conversion unit 411 commonly need 6-way voltage followers, and the design of the 6-way voltage followers is not limited to the use of a 6-way integrated operational amplifier, and can also be other equivalent modes such as a mode of combining a 4-way operational amplifier and a 2-way operational amplifier.

In this embodiment, through the setting to voltage conversion unit, can be so that the sampled signal that gets into metering module is more accurate to when handling sampled signal, handle jointly through software, hardware, make the measurement of electric energy more accurate.

Further, referring to fig. 3 again, the current converting unit 42 includes an a-phase current signal converter 420, a B-phase current signal converter 421 and a C-phase current signal converter 422, an input end of the a-phase current signal converter 420, an input end of the B-phase current signal converter 421 and an input end of the C-phase current signal converter 422 are connected to an output end of the current sampling module 30, and an output end of the a-phase current signal converter 420, an output end of the B-phase current signal converter 421 and an output end of the C-phase current signal converter 422 are respectively connected to the metering unit 43.

The a-phase current signal converter 420, the B-phase current signal converter 421 and the C-phase current signal converter 422 perform signal conversion on the input a-phase, B-phase and C-phase currents, respectively, and specifically, the current signal converter is a sigma-delta ADC, which can make the processing of the current signal more accurate.

It should be noted that, when the actual circuit is implemented, the metering module 40 does not adopt a metering chip, but adopts an SOC chip with multiple analog sampling front ends; more specifically, the metering module 40 includes not only a metering SOC chip but also voltage follower circuits for respective voltage signal channels; the SOC chip of the metering unit comprises 6-path single-end input supporting SAR ADC and 3-path sigma-delta ADC input, under the same signal measurement channel requirement, as many as possible single-end input supporting SAR ADC channels are provided so as to reduce the number of ADCs, IO pins and cost of the chip as much as possible, and at the same time, the metering SOC chip also comprises at least two-path serial ports and a plurality of GPIO ports,

the output signals of the two groups of voltage sampling modules are connected to 6 paths of SAR ADC input channels of the metering unit, and meanwhile, in order to enable the two groups of three-phase voltage signals to be isolated from each other before entering an SOC chip SAR ADC of the metering unit, a voltage follower circuit is introduced before each SAR ADC is input; the output signal of the current sampling module is directly connected into a 3-way sigma-delta ADC of the metering unit; the measurement unit SOC determines which path of SAR ADC input sampled voltage signal and which path of sigma-delta ADC sampled current signal are adopted by the measurement unit for measurement according to actual field configuration and a configuration command issued by the multi-channel control equipment.

Further, referring to fig. 5, the first voltage sampling module 10 and the second voltage sampling module 20 respectively include an a-phase voltage sampling unit 101, a B-phase voltage sampling unit 102, and a C-phase voltage sampling unit 103;

the input ends of the a-phase voltage sampling unit 101, the B-phase voltage sampling unit 102 and the C-phase voltage sampling unit 103 of the first voltage sampling module 10 are the input ends of the first voltage sampling module 10, and are respectively connected with the a-phase line UA1, the B-phase line UB1 and the C-phase line UC1 of the first path of three-phase power, and the output ends of the a-phase voltage sampling unit 101, the B-phase voltage sampling unit 102 and the C-phase voltage sampling unit 103 of the first voltage sampling module 10 are the output ends of the first voltage sampling module 10;

the input ends of the a-phase voltage sampling unit 101, the B-phase voltage sampling unit 102 and the C-phase voltage sampling unit 103 of the second voltage sampling module 20 are the input ends of the second voltage sampling module 20, and are respectively connected with the a-phase line UA2, the B-phase line UB2 and the C-phase line UC2 of the second three-phase circuit, and the output ends of the a-phase voltage sampling unit 101, the B-phase voltage sampling unit 102 and the C-phase voltage sampling unit 103 of the second voltage sampling module are the output ends of the second voltage sampling module 20.

The a-phase voltage sampling unit 101, the B-phase voltage sampling unit 102, and the C-phase voltage sampling unit 103 may be set according to an actual circuit, for example, referring to fig. 6, the a-phase voltage sampling unit 101, the B-phase voltage sampling unit 102, and the C-phase voltage sampling unit 103 may include a voltage dividing resistor, a voltage sampling resistor, and a voltage transformer, respectively;

the first ends of voltage dividing resistors of the A-phase voltage sampling unit, the B-phase voltage sampling unit and the C-phase voltage sampling unit are respectively connected with an A-phase line, a B-phase line and a C-phase line of a three-phase voltage, the second ends of the voltage dividing resistors are connected with the primary side of the voltage transformer, the secondary side of the voltage transformer is connected with the first end of the sampling resistor, and the second ends of the sampling resistors respectively output an A-phase voltage signal, a B-phase voltage signal and a C-phase voltage signal;

the second end of the sampling resistor of the first voltage sampling module 10 is the output end of the first voltage sampling module 10, and the second end of the sampling resistor of the second voltage sampling module 10 is the output end of the second voltage sampling module 20.

The first voltage sampling module 10 samples three-phase input voltages of UA1, UB1 and UC1, wherein UA1 is connected to a primary side of a UA1 voltage transformer through a UA1 divider resistor, and a secondary side of a UA1 voltage transformer is connected to a UA1 sampling resistor to generate a sampling voltage signal UA 1; the same UB1 is connected to the primary side of a UB1 voltage transformer through a UB1 voltage dividing resistor, and a sampling voltage signal UB1 is generated after the secondary side of the UB1 voltage transformer is connected to a UB1 sampling resistor; the same UC1 is connected to the primary side of a UC1 voltage transformer through a UC1 voltage dividing resistor, and a sampling voltage signal UC1 is generated after the secondary side of the UC1 voltage transformer is connected to a UC1 sampling resistor; the second voltage sampling module 20 processes the set of three-phase input voltages UA2, UB2, UC3 by the second voltage sampling module 20 in the same processing manner to output sampled voltage signals UA2, UB2, UC 2. It should be noted that ua1, ub1, uc1 are pure signals containing the voltage signal reference signal 1, ua2, ub2, uc2 are pure signals containing the voltage signal reference signal 2; the voltage signal reference 1 and the voltage signal reference 2 can be output by the SOC and generated by a circuit, the voltage signal reference 1 and the voltage signal reference 2 have the same amplitude, according to actual needs, for example, under the condition of wiring of a group of three-phase voltages and 8-circuit three-phase voltages, the two voltages can be combined into one, and the voltage sampling module 10 can be configured with different parameters to meet different three-phase voltage input requirements.

Further, referring to fig. 7, the current sampling module 30 includes an a-phase current sampling unit 301, a B-phase current sampling unit 302, and a C-phase current sampling unit 303,

the input ends of the a-phase current sampling unit 301, the B-phase current sampling unit 302 and the C-phase current sampling unit 303 are the input ends of the current sampling module 30, and the output ends of the a-phase current sampling unit 301, the B-phase current sampling unit 302 and the C-phase current sampling unit 303 are the output ends of the current sampling module 30.

The current sampling module 30 samples the currents IA, IB, and IC, and outputs sampling current signals IA, IB, and IC after the currents are input through the respective sampling units, in a manner similar to the processing manner of the voltage sampling units. Of course, the specific circuit of the current sampling module 30 may configure different parameters to meet different three-phase current input requirements, for example, referring to fig. 8, the a-phase current sampling unit 301, the B-phase current sampling unit 302, and the C-phase current sampling unit 303 respectively include a current transformer and a current sampling resistor;

the first ends of the current transformers of the phase a current sampling unit 301, the phase B current sampling unit 302 and the phase C current sampling unit 303 are respectively connected with the phase a current IA, the phase B current IB and the phase C current IC of the three-phase power, the second ends of the current transformers are connected with the first end of the current sampling resistor, the second ends of the current sampling resistor respectively output a phase a current signal IA, a phase B current signal IB and a phase C current signal IC, and the second ends of the current sampling resistor are the output ends of the current sampling module 30.

After the A-phase current IA, the B-phase current IB and the C-phase current IC are connected through respective current transformers, sampling current signals Ia, Ib and IC are respectively output to be used for a lower-level circuit to convert current, and therefore the sampling current signals and the voltage signals are calculated to measure electric energy.

Referring to fig. 9, the present invention further provides a multi-channel metering circuit, in an embodiment, the multi-channel metering circuit includes a control module 50 and at least one metering circuit 60, an output end of the metering circuit 60 is connected to the control module 50, and a structure of the metering circuit 60 may refer to the above-mentioned embodiment, and it should be noted that each metering circuit 60 includes a first voltage sampling module 10 and a second voltage sampling module 20, and the first voltage sampling module 10 and the first voltage sampling module 20 of each metering circuit 60 may be respectively arranged, so that each metering circuit 60 separately measures electric energy of a loop with two voltage inputs; of course, the first voltage sampling module 10 and the second voltage sampling module 20 of each metering circuit 60 may be shared; or a part of the first voltage sampling module 10 and a part of the second voltage sampling module 20 are shared.

The control module 50 is configured to send a metering selection signal to the metering module 40, so that the metering module 40 selects the voltage signal input by the first voltage sampling module 10 or the voltage signal input by the second voltage sampling module 20 to obtain a voltage signal, and performs electric energy metering with the current signal output by the current sampling module 30. Furthermore, the control module 50 may communicate with the metering modules 40, and the control module 50 may count the electric energy information metered by each metering module 40.

Referring to fig. 10, for example, the multi-channel metering circuit includes eight metering circuits, and when the multi-channel metering circuit is used for metering two paths of voltage signals and eight paths of current signals, all the metering circuits 60 share the same first voltage sampling module 10 to sample the same path of voltage signals, and the second voltage sampling module 20 shares the same first voltage sampling module 10 to sample the other path of voltage signals. The metering module can select to conduct selective metering in the two paths of three-phase voltage signals through software, namely, the voltage signal sampled by the first voltage module or the voltage signal sampled by the second voltage module is selected. Based on this, a device using the circuit can realize that: 1-circuit voltage and 8-circuit three-phase current are supported to be output and measured; or, 1-path voltage is supported, and only 1-path, 2-path and at most 8-path current output are supported and measured; the system can also support two paths of three-phase voltages, each path of three-phase voltage has the measurement of 4 paths of three-phase current output, and the specific implementation mode can be configured according to an actual circuit.

In this embodiment, the voltage signal input by the metering module 40 is switched by software, and a hardware device is not required to switch the signal, so that the circuit structure is simple, and no hardware signal loss occurs; even if a plurality of metering modules and input signals are involved, the channel of each metering module can be individually configured, so that the adaptability is strong, and the application range is wide; the SAC ADC is adopted for voltage sampling, the sigma-delta ADC is adopted for current sampling, and a signal isolation module based on an operational amplifier circuit is used as a voltage follower at the front end of the SAR ADC, so that the input impedance of a sampling point on each voltage signal bus is greatly increased, the output impedance of a signal entering the SAR ADC is reduced, and the problems of signal attenuation and interference caused by the long signal line are effectively solved; under the condition that the 8 metering modules sample the voltage signals at the same time, mutual crosstalk of buses on the A phase, the B phase and the C phase on the first voltage signal bus or the second voltage signal bus among the modules is facilitated.

Further, referring to fig. 11, the multi-channel metering circuit further includes a communication module 70, the communication module 70 is connected to the control module 50,

the communication module 70 is configured to receive a metering selection signal and transmit the metering selection signal to the control module 50, so as to control the metering module 40 to perform corresponding electric energy metering;

the communication module 70 is further configured to transmit the electric energy information measured by the measuring module 40.

The communication module 70 may transmit the electric energy information measured by each measuring module 40 to the remote control end, and may also receive a measurement selection signal issued by the remote control end, so as to implement the control of the remote control end on the circuit, thereby improving the efficiency of the control and saving the labor cost.

Furthermore, the multichannel metering circuit further comprises a power conversion module 80, wherein an input end of the power conversion module 80 is connected with a first power supply, a first output end of the power conversion module 80 outputs a second power supply, and a second output end of the power conversion module 80 outputs a third power supply;

the second power source is connected to the power end of the metering module 60, and the third power source is connected to the power end of the communication module 70.

The power conversion module 80 is used for converting the first power with higher voltage into a direct current power suitable for circuits such as a metering module, a communication module, a control circuit and the like. Specifically, the second power supply and the third power supply are isolated from each other, so that the power supply signals are less interfered with each other, and are more stable.

The present invention also provides a metering apparatus comprising: the structure of the metering circuit can refer to the above embodiments, and is not described herein again; or, the structure of the multi-channel metering circuit may refer to the above embodiments, and will not be described herein again. It should be understood that, since the metering device of the present embodiment adopts the technical solution of the above metering circuit or multi-channel metering circuit, the metering device has all the advantages of the above metering circuit or multi-channel metering circuit.

The above description is only a preferred embodiment of the present invention, and not intended to limit the scope of the present invention, and all modifications of equivalent structures and equivalent processes, which are made by using the contents of the present specification and the accompanying drawings, or directly or indirectly applied to other related technical fields, are included in the scope of the present invention.