Onboard isolated single-phase and three-phase electric energy acquisition circuit

Abstract

The utility model discloses an onboard isolated single-phase and three-phase electric energy acquisition circuit, which comprises a metering circuit, a current sampling circuit, a voltage sampling circuit, a power supply circuit, an MCU (Microprogrammed Control Unit) circuit, a mode selection circuit, a voltage isolation circuit and a signal isolation circuit. According to the utility model, through combination of the metering circuit, the current sampling circuit, the voltage sampling circuit, the power supply circuit, the MCU circuit, the mode selection circuit, the voltage isolation circuit and the signal isolation circuit, the circuit can carry out corresponding sampling according to the type of input alternating current, i.e., sampling of voltage and current is carried out according to single-phase power when the single-phase power is input; when three-phase electricity is input, voltage and current are adopted according to the three-phase electricity, and therefore the sampling circuit can be used for collecting single-phase electricity and three-phase electricity at the same time.

Description

Technical Field

[0001] This utility model relates to an onboard isolated single- or three-phase power acquisition circuit. Background Technology

[0002] Electricity acquisition modules are used to collect electricity consumption data and are widely used in power systems. Single-phase and three-phase electricity are widely used in production and daily life. Currently, when collecting electricity consumption data for single-phase and three-phase electricity, separate electricity acquisition modules are used for each. That is, electricity acquisition modules can only collect data for single-phase or three-phase electricity and cannot achieve universal compatibility. Utility Model Content

[0003] To address the aforementioned problems, this utility model provides an onboard isolated single-phase and three-phase power acquisition circuit. Through optimized circuit design, it can adaptively acquire power according to actual access conditions, effectively solving the problems mentioned in the background art.

[0004] The technical solution adopted in this utility model is:

[0005] An onboard isolated single-phase and three-phase power acquisition circuit includes a metering circuit, a current sampling circuit, a voltage sampling circuit, a power supply circuit, an MCU circuit, a mode selection circuit, a voltage isolation circuit, and a signal isolation circuit. The metering circuit is connected to the current sampling circuit, the voltage sampling circuit, and the mode selection circuit, respectively. The metering circuit is connected to the MCU circuit through the signal isolation circuit. The power supply circuit is connected to the metering circuit, the MCU circuit, the mode selection circuit, and the signal isolation circuit through the power supply isolation circuit, respectively.

[0006] Preferably, the current sampling circuit includes three current detection circuits, each used to detect the current of a live wire.

[0007] The three current detection circuits can detect the current of the three live wires respectively. When working simultaneously, they can be used for current detection of three-phase lines, while one of them can be used for current detection of a single-phase line.

[0008] Preferably, the voltage sampling circuit includes three voltage detection circuits, each of which is used to detect the voltage of a live wire.

[0009] The three voltage detection circuits can detect the voltage of the three live wires respectively. When working simultaneously, they can be used for voltage detection of three-phase lines, while one of them can be used for voltage detection of a single-phase line.

[0010] Preferably, the mode selection circuit includes four detection lines connected in parallel. One end of each of the four detection lines is connected and grounded, and the other end is connected to the metering circuit. Resistors (R9, R10, R11, R12) are provided on each of the four detection lines. The detection lines are connected to the power isolation circuit through resistors (R3, R4, R5, R6) at the end of the resistors (R9, R10, R11, R12) closest to the metering circuit.

[0011] The mode selection circuit can automatically switch the acquisition logic according to the type of power supply (single-phase or three-phase).

[0012] Preferably, the system also includes a communication circuit, which is connected to the MCU circuit and is connected to the power supply circuit via a power isolation circuit.

[0013] The communication circuit has excellent expansion capabilities. It can be directly connected to a display screen for display, or it can be connected to a smart meter, energy management system or IoT terminal, supporting future functional upgrades (such as harmonic analysis and demand statistics).

[0014] The power supply circuit uses one of the live wires for power supply. The power supply circuit converts high-voltage AC power into low-voltage DC power for output, powering the metering circuit, MCU circuit, mode selection circuit, signal isolation circuit and communication circuit.

[0015] This invention combines a metering circuit, a current sampling circuit, a voltage sampling circuit, a power supply circuit, an MCU circuit, a mode selection circuit, a voltage isolation circuit, and a signal isolation circuit. This allows the circuit to perform corresponding sampling based on the type of AC input. Specifically, when single-phase power is input, voltage and current are sampled based on single-phase power, and when three-phase power is input, voltage and current are sampled based on three-phase power. Thus, the sampling circuit of this invention can be used simultaneously for the acquisition of both single-phase and three-phase power.

[0016] The beneficial effects of this utility model are:

[0017] 1. Adaptive acquisition mode: Through the mode selection circuit (configured with multiple parallel detection lines and resistor network), the system can automatically switch the acquisition logic according to the power supply type (single-phase or three-phase) without replacing the hardware module. For example, when the input is single-phase, only the sampling circuit of the corresponding live wire and neutral wire is activated, and when the input is three-phase, the three live wire signals are acquired simultaneously.

[0018] 2. Dynamic sampling optimization: The current sampling circuit adopts three independent detection channels (each live wire is equipped with a dedicated current transformer), and the voltage sampling circuit achieves balanced acquisition through a voltage divider resistor network to ensure the accuracy of data when the three-phase load is unbalanced;

[0019] 3. Modular integration: The high integration of metering circuits, current / voltage sampling circuits and isolation circuits enables the same hardware platform to be compatible with single-phase (220V) and three-phase (380V) application scenarios, reducing equipment redundancy and maintenance costs, and is especially suitable for industrial and civil scenarios that require flexible switching of power supply modes;

[0020] 4. Power isolation circuits and signal isolation circuits (such as optocoupler isolation) achieve electrical isolation between metering circuits, MCU circuits and communication circuits, effectively suppressing common-mode interference and avoiding the impact of high-voltage side faults on the low-voltage control terminal;

[0021] 5. The introduction of TVS diodes and PTC resettable fuses further protects against overvoltage, overcurrent and short circuit risks. The use of metal film power resistors (such as MMF204) and surface mount capacitors optimizes the signal sampling path and reduces the impact of high-frequency noise on measurement accuracy.

[0022] 6. Low-cost solution: Reduce the number of external components and lower BOM costs through onboard integrated design (such as surface mount components and universal XA sockets); the selection of isolated power supply modules balances performance and cost, making them suitable for large-scale deployment; the communication circuit reserves standardized interfaces (such as 485 chips), which can be seamlessly connected to smart meters, energy management systems or IoT terminals, support future functional upgrades (such as harmonic analysis and demand statistics), and can also directly output detection information to displays, etc.

[0023] 7. Traditional solutions require separate configuration of single-phase / three-phase acquisition modules, while this design achieves "multi-purpose use on one board" through mode selection circuit, saving equipment space and procurement costs. Furthermore, existing modules often neglect isolation design, resulting in insufficient anti-interference capability. This solution significantly improves system reliability through a fully isolated architecture. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the structure of this utility model;

[0025] Figure 2 For MCU circuits;

[0026] Figure 3 This is a current sampling circuit;

[0027] Figure 4 This is a voltage sampling circuit;

[0028] Figure 5 For power supply circuit;

[0029] Figure 6 It is a power isolation circuit;

[0030] Figure 7 For metering circuits;

[0031] Figure 8For mode selection circuit;

[0032] Figure 9 For communication circuits;

[0033] Figure 10 This is a signal isolation circuit. Detailed Implementation

[0034] It should be noted that the following detailed descriptions are illustrative and intended to provide further explanation of this application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains.

[0035] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0036] Furthermore, in the description of this utility model, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "clockwise," and "counterclockwise," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0037] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, unless otherwise stated, "a plurality of" means two or more, unless otherwise expressly defined.

[0038] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0039] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0040] The present invention will now be described in further detail with reference to specific embodiments and accompanying drawings.

[0041] like Figure 1-10 As shown, an onboard isolated single-phase and three-phase power acquisition circuit includes a metering circuit, a current sampling circuit, a voltage sampling circuit, a power supply circuit, an MCU circuit, a mode selection circuit, a voltage isolation circuit, a signal isolation circuit, and a communication circuit. The metering circuit is connected to the current sampling circuit, the voltage sampling circuit, and the mode selection circuit, respectively. The metering circuit is connected to the MCU circuit through the signal isolation circuit. The communication circuit is connected to the MCU circuit. The power supply circuit is connected to the metering circuit, the MCU circuit, the mode selection circuit, the signal isolation circuit, and the communication circuit through the power supply isolation circuit.

[0042] The current sampling circuit includes three current detection circuits, each used to detect the current of a live wire.

[0043] The voltage sampling circuit includes three voltage detection circuits, each used to detect the voltage of a live wire.

[0044] The mode selection circuit includes four detection lines connected in parallel. One end of each detection line is connected to ground, and the other end is connected to a metering circuit. Each of the four detection lines is equipped with a resistor (R9, R10, R11, R12). The detection lines are connected to a power isolation circuit through resistors (R3, R4, R5, R6) at the end of the resistors (R9, R10, R11, R12) closest to the metering circuit.

[0045] Figure 2 The diagram illustrates the MCU circuit, where +5V is the power supply circuit powered through a power isolation circuit, PWM is the port connected to the signal isolation circuit, and USART0_DE, USART0_RX, and USART0_TX are the ports connected to the communication circuit.

[0046] Figure 3 The diagram illustrates a current sampling circuit, which consists of three identical current detection circuits, where IA1N, IA1P, IB1N, IB1P, IC1N, and IC1P are ports connected to the metering circuit.

[0047] Figure 4 The voltage sampling circuit is illustrated, consisting of three identical voltage detection circuits. UA, UB, and UC are ports connected to the three live wires, while UA2P, UB2P, and UC2P are ports connected to the metering circuit.

[0048] Figure 5 The diagram illustrates a power supply circuit that connects to either a live wire or a neutral wire. In the diagram, UN is the port connected to the neutral wire, UC is the port connected to one of the live wires, and +5V is the voltage output terminal of the power supply circuit.

[0049] Figure 6 The diagram illustrates a power isolation circuit. There are two +5V lines in the diagram. One is an input connected to the +5V of the power supply circuit, and the other is an output connected to the metering circuit, MCU circuit, mode selection circuit, signal isolation circuit, and communication circuit.

[0050] Figure 7 The metering circuit is illustrated. The +5V power supply is provided by the power isolation circuit and connected to the +5V output of the power isolation circuit. The CF port is connected to the PWM port of the MCU circuit after passing through the signal isolation circuit. The S1, S0, SCF, and ADD ports are connected to the mode selection circuit.

[0051] Figure 8 The diagram illustrates the mode selection circuit, where the +5V power supply is provided by the power isolation circuit and connected to the +5V output of the power isolation circuit.

[0052] Figure 9The diagram illustrates the communication circuit, where the +5V power supply is provided by the power isolation circuit and connected to the +5V output of the power isolation circuit.

[0053] Figure 10 The diagram illustrates the signal isolation circuit, where the +5V power supply circuit is powered through the power isolation circuit and connected to the +5V output of the power isolation circuit. The CF port is connected to the metering circuit, and the PWM port is connected to the MCU circuit.

[0054] Finally, it should be noted that the above examples are merely specific embodiments of this utility model. Obviously, this utility model is not limited to the above embodiments and can have many variations. All variations that can be directly derived or conceived by those skilled in the art from the disclosure of this utility model should be considered within the protection scope of this utility model.

Claims

1. An onboard isolated single-phase and three-phase power acquisition circuit, characterized in that, It includes a metering circuit, a current sampling circuit, a voltage sampling circuit, a power supply circuit, an MCU circuit, a mode selection circuit, a voltage isolation circuit, and a signal isolation circuit. The metering circuit is connected to the current sampling circuit, the voltage sampling circuit, and the mode selection circuit, respectively. The metering circuit is connected to the MCU circuit through the signal isolation circuit. The power supply circuit is connected to the metering circuit, the MCU circuit, the mode selection circuit, and the signal isolation circuit through the power supply isolation circuit, respectively.

2. The onboard isolated single-phase and three-phase power acquisition circuit according to claim 1, characterized in that, The current sampling circuit includes three current detection circuits, each used to detect the current of a live wire.

3. The onboard isolated single-phase and three-phase power acquisition circuit according to claim 1, characterized in that, The voltage sampling circuit includes three voltage detection circuits, each used to detect the voltage of a live wire.

4. The onboard isolated single-phase and three-phase power acquisition circuit according to claim 1, characterized in that, The mode selection circuit includes four detection lines connected in parallel. One end of each detection line is connected to ground, and the other end is connected to a metering circuit. Each of the four detection lines is equipped with a resistor (R9, R10, R11, R12). The detection lines are connected to a power isolation circuit through resistors (R3, R4, R5, R6) at the end of the resistors (R9, R10, R11, R12) closest to the metering circuit.

5. The onboard isolated single-phase and three-phase power acquisition circuit according to claim 1, characterized in that, It also includes a communication circuit, which is connected to the MCU circuit and is connected to the power supply circuit through a power isolation circuit.

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