Discrete current acquisition system

Abstract

The invention discloses a discrete current acquisition system which comprises a voltage acquisition and power supply module U and discrete current acquisition modules I. The voltage acquisition and power supply module U is connected with the discrete current acquisition modules I. The multiple discrete current acquisition modules I are connected in series. Wherein the voltage acquisition and power supply module U focuses on power grid voltage acquisition and power supply for the current acquisition module I. The current acquisition module I focuses on current acquisition, in conclusion, the system overcomes the defects in the prior art, is reasonable in design, improves the convenience and accuracy of data integration, and has relatively high social use value and application prospect.

Description

Technical Field

[0001] This invention relates to the field of current acquisition technology, and in particular to a discrete current acquisition system. Background Technology

[0002] With the rapid development of power grid energy measurement technology, the demand for measuring power grid usage is growing rapidly. In various complex and ever-changing application scenarios, accurate and efficient acquisition of current data under different environments has become crucial to ensuring stable power grid operation and optimizing energy distribution. While traditional energy measurement equipment meets basic measurement needs to a certain extent, its limitations are becoming increasingly apparent when facing specific scenarios, such as distributed energy resource integration, smart grid monitoring, and temporary power quality testing.

[0003] In particular, when it is necessary to monitor current data at multiple points simultaneously, traditional solutions often require the deployment of a large number of electricity meters. This not only increases hardware costs but also brings a series of problems such as complex wiring, difficult maintenance, and cumbersome data integration. In addition, traditional equipment is also insufficient in terms of portability and flexibility, making it difficult to meet the needs of rapid deployment and flexible relocation.

[0004] In view of this, the present invention proposes an innovative discrete current acquisition system, which aims to overcome the limitations of the prior art and provide an efficient, economical and convenient current data acquisition solution. Summary of the Invention

[0005] To address the problems mentioned in the background section, this invention provides a discrete current acquisition system.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A discrete current acquisition system includes a voltage acquisition and power supply module U and a discrete current acquisition module I, which are connected together. Multiple discrete current acquisition modules I are connected in series. The voltage acquisition and power supply module U is dedicated to acquiring grid voltage and supplying power to the current acquisition modules I, while the current acquisition modules I are dedicated to acquiring current.

[0008] Preferably, the voltage acquisition and power supply module U supplies power to the current acquisition module I via a PoE power supply.

[0009] Preferably, the discrete current acquisition module I communicates with the voltage acquisition and power supply module U and the current acquisition module I via an RS-485 circuit.

[0010] Preferably, the discrete current acquisition module I includes a power supply circuit, a current acquisition circuit, an MCU circuit, and a display circuit.

[0011] Preferably, the current acquisition circuit includes a current transformer and an operational amplifier circuit, wherein: the current transformer converts the large current in the power grid into a small current signal, which is then amplified by the operational amplifier circuit, and the operational amplifier circuit has an amplification factor of 15 times.

[0012] Preferably, the current acquisition circuit adopts a two-stage amplification design.

[0013] Preferably, the operational amplifier circuit includes resistors RA3, RA2, and RA1, capacitors C27 and CA2, and an operational amplifier. Resistor RA3 converts the small current signal coupled by the mutual inductor into a voltage signal.

[0014] Preferably, one end of resistor RA3 is connected to the positive terminal of the operational amplifier through resistor RA5, and the other end of resistor RA3 is connected to one end of resistor RA2 and to the negative terminal of the operational amplifier through resistor RA4.

[0015] Preferably, one end of the resistor RA1 is connected to the output terminal of the operational amplifier, and the output current of the operational amplifier circuit is:

[0016] V IA1 =(RA1 / RA2)*V IAIN +V offfect

[0017] Where: V IAIN V is the input voltage of the operational amplifier circuit. offect This is the bias voltage, and V offect =1.62V.

[0018] Compared with the prior art, the beneficial effects of the present invention are:

[0019] 1. Data integration: The discrete current acquisition modules I in different regions can be integrated into the voltage acquisition and power supply module U for unified reading, which improves the convenience and accuracy of data integration and facilitates intelligent management and maintenance of measurement data by users;

[0020] 2. Reduced costs: Significantly reduced hardware costs, eliminating the need to purchase a large number of separate electricity meters;

[0021] 3. Simplified architecture: Power supply via PoE and data transmission via RS-485 circuitry simplify the system architecture, reduce wiring workload, and improve system maintainability.

[0022] 4. Discrete and portable design: The system is designed to be compact and portable, adaptable to various complex environments, and meet the needs of rapid deployment and flexible adjustment.

[0023] In summary, this invention overcomes the shortcomings of existing technologies, has a reasonable design, improves the convenience and accuracy of data integration, and has high social value and application prospects. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 This is a schematic diagram illustrating the module connections of the present invention;

[0026] Figure 2 This is a schematic diagram of the current acquisition module I of the present invention;

[0027] Figure 3 The circuit diagram of the operational amplifier circuit of the present invention is shown below. Figure 1

[0028] Figure 4 The circuit diagram of the operational amplifier circuit of the present invention is shown below. Figure 2 Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0030] Example 1

[0031] Reference Figure 1 A discrete current acquisition system includes a voltage acquisition and power supply module U and a discrete current acquisition module I. The voltage acquisition and power supply module U and the discrete current acquisition module I are connected. The voltage acquisition and power supply module U is focused on acquiring grid voltage and supplying power to the current acquisition module I. The current acquisition module I is used to focus on current acquisition.

[0032] Furthermore, the voltage acquisition and power supply module U supplies power to the current acquisition module I via PoE (Power over Ethernet). With this power supply method, the voltage acquisition and power supply module U can achieve power supply and communication with the current acquisition module I simply through a conventional Ethernet cable.

[0033] Furthermore, there are 32 discrete current acquisition modules I, which are connected in series. Each discrete current acquisition module I includes two RS-485 circuits. One RS-485 circuit is used to communicate with the preceding voltage acquisition and power supply module U or the current acquisition module I, and the other RS-485 circuit communicates with the following current acquisition module I. Through RS-485 communication, stable and high-speed communication is achieved between the voltage acquisition and power supply module U and up to 32 discrete current acquisition modules I, which greatly improves the efficiency and coverage of data acquisition.

[0034] Reference Figure 2 The discrete current acquisition module I also includes a power supply circuit, a current acquisition circuit, an MCU circuit, and a display circuit. The power supply circuit converts the 24V power supplied by the voltage acquisition and power supply module U into the 5V and 3.3V power supplies required by the internal circuitry at each stage.

[0035] The current acquisition circuit consists of a 100A / 66.66mA current transformer and an operational amplifier circuit. The current transformer converts the large current in the power grid into a small current signal, which is then converted into a small voltage signal by the operational amplifier circuit and amplified before being transmitted to the MCU circuit for processing.

[0036] The MCU circuit performs calculations and reconstructions on the small voltage signal to obtain the actual grid current information, which is then displayed on the LCD screen through the display circuit.

[0037] Furthermore, the current acquisition circuit adopts a two-stage amplification design. When the grid current exceeds 20A, the voltage signal coupled and converted by the current transformer is directly amplified by the operational amplifier and then transmitted to the MCU circuit for processing. When the grid current is less than 20A, the voltage waveform output by the current transformer has too small an amplitude and is easily affected by interference distortion, which affects the sampling accuracy. Therefore, the MCU circuit has an internal amplification circuit to achieve two-stage amplification and improve the sampling accuracy of small current signals.

[0038] Reference Figure 3 and Figure 4 The operational amplifier circuit includes resistors RA3, RA2, and RA1, capacitors C27 and CA2, and an operational amplifier. Resistor RA3 converts the small current signal coupled by the mutual inductor into a voltage signal.

[0039] One end of resistor RA3 is connected to one end of capacitor C27 and is connected to the positive terminal of operational amplifier through resistor RA5. The other end of resistor RA3 is connected to one end of resistor RA2 and the other end of capacitor C27 and is connected to the negative terminal of operational amplifier through resistor RA4. Capacitor C27 is used to filter out interference noise from the mutual inductor.

[0040] One end of resistor RA1 is connected to the output of the operational amplifier, and the other end of resistor RA1 is connected to one end of capacitor CA2. Capacitor CA2 is used to filter out interference signals.

[0041] Furthermore, based on the concepts of virtual short and virtual open of operational amplifiers, we can obtain:

[0042] V IA1 =(RA1 / RA2)*V IAIN +V offect

[0043] Among them, V IA1 V is the output voltage of the operational amplifier circuit. IAIN V is the input voltage of the operational amplifier circuit. offect This is the bias voltage, and V offect =1.65V.

[0044] Working principle: When the system is in use, the voltage acquisition and power supply module U supplies power to multiple current acquisition modules I via PoE and acquires the grid voltage. The current acquisition modules I can acquire multiple current data and transmit them to the voltage acquisition and power supply module U via RS-485 communication protocol. The voltage acquisition and power supply module U can acquire and integrate current data from different areas, which greatly improves the efficiency and coverage of data acquisition.

[0045] When current acquisition module I is working, the power supply circuit converts the 24V power supply provided by voltage acquisition and power supply module U into the 5V and 3.3V power supplies required by the internal circuits at each stage. The current acquisition circuit consists of a 100A / 66.66mA current transformer and an operational amplifier circuit. The current transformer converts the large current in the power grid into a small current signal, which is then converted into a small voltage signal by the operational amplifier circuit and amplified before being transmitted to the MCU circuit for processing. The MCU circuit performs calculations and reconstruction on the small voltage signal to obtain the actual power grid current information.

[0046] The control method of this invention is automatic control through a controller. The control circuit of the controller can be implemented by simple programming by those skilled in the art. The power supply is also common knowledge in the art. Furthermore, since this invention is mainly used to protect mechanical devices, the control method and circuit connection will not be explained in detail here.

[0047] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A discrete current acquisition system, characterized in that: It includes a voltage acquisition and power supply module U and a discrete current acquisition module I, wherein the voltage acquisition and power supply module U and the discrete current acquisition module I are connected, and multiple discrete current acquisition modules I are connected in series. Among them, the voltage acquisition and power supply module U is focused on acquiring grid voltage and supplying power to the current acquisition module I, while the current acquisition module I is used to focus on current acquisition.

2. The discrete current acquisition system according to claim 1, characterized in that: The voltage acquisition and power supply module U supplies power to the current acquisition module I via a PoE power supply.

3. The discrete current acquisition system according to claim 1, characterized in that: The discrete current acquisition module I communicates with the voltage acquisition and power supply module U and the current acquisition module I via an RS-485 circuit.

4. A discrete current acquisition system according to claim 1, characterized in that: The discrete current acquisition module I includes a power supply circuit, a current acquisition circuit, an MCU circuit, and a display circuit.

5. A discrete current acquisition system according to claim 4, characterized in that: The current acquisition circuit includes a current transformer and an operational amplifier circuit. The current transformer converts the large current in the power grid into a small current signal, which is then amplified by the operational amplifier circuit, which has an amplification factor of 15.

6. A discrete current acquisition system according to claim 4, characterized in that: The current acquisition circuit adopts a two-stage amplification design.

7. A discrete current acquisition system according to claim 5, characterized in that: The operational amplifier circuit includes resistors RA3, RA2, and RA1, capacitors C27 and CA2, and an operational amplifier. Resistor RA3 converts the small current signal coupled by the mutual inductor into a voltage signal.

8. A discrete current acquisition system according to claim 7, characterized in that: One end of resistor RA3 is connected to the positive terminal of the operational amplifier through resistor RA5, and the other end of resistor RA3 is connected to one end of resistor RA2 and to the negative terminal of the operational amplifier through resistor RA4.

9. A discrete current acquisition system according to claim 8, characterized in that: One end of resistor RA1 is connected to the output terminal of the operational amplifier. The output current of the operational amplifier circuit is: In IA1 =(RA1 / RA2)*V IAIN +V offect Where: V IAIN V is the input voltage of the operational amplifier circuit. offect This is the bias voltage, and V offect =1.62V.

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