Detection device for new energy grid-connected metering installation

Abstract

The utility model discloses a detection device for new energy grid-connected metering installation, after the wiring of the new energy grid-connected installation device is completed, a power supply is used for supplying power to a single-chip microcomputer chip, and the single-chip microcomputer is used for controlling the conduction of a detection signal injection relay expansion board and a detection signal reading relay expansion board. A signal interface on a first DC5V relay is controlled to be conducted through a single chip microcomputer, and an access signal of a corresponding signal interface on a detection signal injection relay expansion board flows to a corresponding signal interface on a detection signal reading relay expansion board through a connection wire on a new energy grid-connected metering installation device. A received signal is read through a corresponding signal interface on a second DC5V relay, the received signal is converted into a digital signal by a digital quantity switch sampling circuit and is transmitted into a single-chip microcomputer, and if a detection signal in the single-chip microcomputer is pulled down from a high level to a low level, the new energy grid-connected installation device is correct in wiring; otherwise, the new energy grid-connected installation device fails in wiring. According to the utility model, new energy grid-connected installation automatic detection can be realized.

Description

Technical Field

[0001] This utility model relates to the field of power electronics technology, specifically to a detection device for grid-connected metering installation of new energy sources. Background Technology

[0002] In the power industry, proficiency in metering installation is a crucial indicator of an employee's professional skills. Metering installation encompasses both traditional conventional metering installation and new energy grid-connected metering installation. As the proportion of new energy grid connection gradually increases, the demand for new energy grid-connected metering installation is also growing. Currently, relevant personnel are relatively more familiar with traditional conventional metering installation, but less so with new energy grid-connected metering installation. Therefore, targeted practical training is needed to improve the professional skills of relevant personnel in both new energy grid-connected metering installation and conventional metering installation.

[0003] Metering wiring is intricate and complex, and training relevant personnel inevitably involves checking the correctness of these wiring connections. Manually verifying the correctness of wiring on a large scale is impractical; therefore, an automated checking and judgment system is needed. Consequently, there is an urgent need for a metering assembly training and certification device that can both simulate wiring scenarios and automatically determine the correctness of wiring. Utility Model Content

[0004] To address the problems existing in the prior art, this utility model provides a detection device for the metering installation of new energy grid connection. By setting up a detection signal injection relay expansion board and a detection signal reading relay expansion board, the detection signal is injected in segments to determine the accuracy of the new energy grid connection installation and can accurately locate the incorrect wiring position.

[0005] To achieve the above technical objectives, this utility model adopts the following technical solution: a detection device for new energy grid-connected metering installation, comprising: a power supply, a microcontroller chip, a communication chip, a detection signal injection relay expansion board, a detection signal reading relay expansion board, a digital quantity switch sampling circuit, a first DC5V relay, a second DC5V relay, and a computer. After the new energy grid-connected installation device is wired, the power supply powers the microcontroller chip. The microcontroller controls the conduction of the detection signal injection relay expansion board and the detection signal reading relay expansion board. The detection signal injection relay expansion board sends the access signal of the new energy grid-connected installation device, and the detection signal reading relay expansion board receives the new energy signal. The receiving signal of the energy grid-connected installation device is controlled by a microcontroller to turn on the signal interface of the first DC5V relay. The input signal of the detection signal injected into the corresponding signal interface on the relay expansion board flows through the wiring on the new energy grid-connected metering installation device to the corresponding signal interface on the detection signal reading relay expansion board, and then reads the received signal through the corresponding signal interface on the second DC5V relay. The read received signal is converted into a digital signal by a digital quantity switch sampling circuit and transmitted to the microcontroller. If the detection signal in the microcontroller is pulled from high level to low level, it indicates that the wiring of the new energy grid-connected installation device is correct; otherwise, the wiring of the new energy grid-connected installation device has failed, and the wiring result of the new energy grid-connected installation device is displayed on the computer.

[0006] Furthermore, the power supply includes: a DC12V DC power supply and a DC5V step-down chip. The positive terminal of the DC12V DC power supply is connected to the positive input terminal of the DC5V step-down chip, the negative terminal of the DC12V DC power supply is connected to the negative input terminal of the DC5V step-down chip, the positive output terminal of the DC5V step-down chip is connected to the input terminal of the first DC5V relay, and the negative output terminal of the DC5V step-down chip is grounded.

[0007] Furthermore, the A-phase, B-phase, C-phase, and N-phase input terminals of the first DC5V relay are all connected to the positive output terminal of the DC5V step-down chip. The A-phase output terminal of the first DC5V relay is connected to the A-phase input terminal of all relay units on the detection signal injection relay expansion board. The B-phase output terminal of the first DC5V relay is connected to the B-phase input terminal of all relay units on the detection signal injection relay expansion board. The C-phase output terminal of the first DC5V relay is connected to the C-phase input terminal of all relay units on the detection signal injection relay expansion board. The N-phase output terminal of the first DC5V relay is connected to the N-phase input terminal of all relay units on the detection signal injection relay expansion board. Each relay unit on the detection signal injection relay expansion board is connected to the access signal interface on the new energy grid-connected metering installation device.

[0008] Furthermore, the input terminal of each relay unit on the detection signal reading relay expansion board is connected to the signal receiving interface on the new energy grid-connected metering installation device. The A-phase output terminal of all relay units on the detection signal reading relay expansion board is connected to the A-phase input terminal of the second DC5V relay. The B-phase output terminal of all relay units on the detection signal reading relay expansion board is connected to the B-phase input terminal of the second DC5V relay. The C-phase output terminal of all relay units on the detection signal reading relay expansion board is connected to the C-phase input terminal of the second DC5V relay. The N-phase output terminal of all relay units on the detection signal reading relay expansion board is connected to the N-phase input terminal of the second DC5V relay.

[0009] Furthermore, the A-phase output terminal, B-phase output terminal, C-phase output terminal and N-phase output terminal of the second DC5V relay are respectively connected to the sampling terminal of a digital quantity switch sampling circuit.

[0010] Furthermore, the microcontroller chip is model MB9BF218SPMC. Each KK terminal of the microcontroller chip is connected to the signal terminal of a relay unit on the detection signal injection relay expansion board or the signal terminal of a relay unit on the detection signal reading relay expansion board. Each SEL_K terminal of the microcontroller chip is connected to the signal terminal of the first DC5V relay or the signal terminal of the second DC5V relay. Each XK terminal of the microcontroller chip is connected to the signal terminal of the digital quantity switch sampling circuit.

[0011] Furthermore, each relay unit of the detection signal injection relay expansion board or the detection signal reading relay expansion board consists of four relays connected in parallel. The signal terminal drive circuit of each relay includes: a first resistor R1, a second resistor R2, a third resistor R3, a first transistor T1, a second transistor T2, and a first diode D1. One end of the first resistor R1 is connected to the SEL_K terminal of the microcontroller. The other end of the first resistor R1 is connected to one end of the second resistor R2 and the base of the first transistor T1. The other end of the second resistor R2 and one end of the third resistor R3 are both connected to a 5V voltage. The other end of the third resistor R3 and the collector of the first transistor T1 are both connected to the base of the second transistor T2. The anode of the first diode D1 is connected to the collector of the second transistor T2 and the negative terminal of the relay. The cathode of the first diode D1 is connected to a 12V voltage and the positive terminal of the relay. The emitters of the first transistor T1 and the second diode T2 are both grounded.

[0012] Further, the digital switch sampling circuit includes: a fourth resistor R4, a fifth resistor R5, a sixth resistor R6, a varistor R7, a second light-emitting diode D2, a TLP785 optocoupler U, and a capacitor C. One end of the fourth resistor R4 is connected to the power supply voltage VCC, and the other end of the fourth resistor R4 is connected to the anode of the second light-emitting diode D2. One end of the fifth resistor R5 serves as the signal terminal of the digital switch sampling circuit. The other end of the fifth resistor R5 and the cathode of the second light-emitting diode D2 are both connected to the C1 terminal of the TLP785 optocoupler U. The E1 terminal, the K1 terminal of the TLP785 optocoupler U, and one end of the capacitor C are all grounded. The A1 terminal of the TLP785 optocoupler U is connected to the other end of the capacitor C and one end of the sixth resistor R6. The other end of the sixth resistor R6 and one end of the varistor R7 are both connected to the output terminal of the second DC5V relay. The other end of the varistor R7 is grounded.

[0013] Furthermore, the communication chip is model SN65HVD2082ED, the TXD transmitting port of the communication chip is connected to the USRAT_RX port of the microcontroller chip, and the RXD receiving port of the communication chip is connected to the USRAT_TX port of the microcontroller chip.

[0014] Furthermore, the 485-A and 485-B ports of the communication chip are connected to the computer via a serial port server.

[0015] Compared with the prior art, the present invention has the following beneficial effects: The detection device for new energy grid-connected metering installation of the present invention injects a detection signal into the relay expansion board through the control of the first DV5V relay. The signal then flows through the wiring of the new energy grid-connected metering installation device to the detection signal reading relay expansion board to detect a receiving signal. The receiving signal is then read through the corresponding signal interface on the second DC5V relay. The receiving signal is converted into a digital signal by the digital switch sampling circuit, and the detection signal in the microcontroller is pulled from high level to low level to determine whether the wiring of the new energy grid-connected metering installation device is correct. The detection device realizes automatic judgment, reduces the misjudgment that occurs when manually checking the wiring on a large scale, and saves manpower and time. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the detection device for the new energy grid-connected metering installation of this utility model;

[0017] Figure 2 The circuit diagram for injecting detection signals into the relay expansion board and reading detection signals from the relay expansion board in this utility model is shown.

[0018] Figure 3 This is a circuit diagram of the digital switch sampling circuit in this utility model. Detailed Implementation

[0019] The technical solution of this utility model will be further explained below with reference to the accompanying drawings.

[0020] like Figure 1 This is a schematic diagram of the detection device for new energy grid-connected metering installation according to this utility model. It includes: a power supply, a microcontroller chip, a communication chip, a detection signal injection relay expansion board, a detection signal reading relay expansion board, a digital switch sampling circuit, a first DC5V relay, a second DC5V relay, and a computer. After the new energy grid-connected installation device is wired, the power supply powers the microcontroller chip. The microcontroller controls the conduction of the detection signal injection relay expansion board and the detection signal reading relay expansion board. The detection signal injection relay expansion board sends the access signal from the new energy grid-connected installation device, and the detection signal reading relay expansion board receives the signal from the new energy grid-connected installation device. The system receives a signal, and the microcontroller controls the signal interface on the first DC5V relay to conduct. The input signal to the corresponding signal interface on the relay expansion board is then routed through the wiring on the new energy grid-connected metering installation device to the corresponding signal interface on the detection signal reading relay expansion board. The received signal is then read through the corresponding signal interface on the second DC5V relay. This received signal is converted into a digital signal by a digital switch sampling circuit and transmitted to the microcontroller. If the detection signal in the microcontroller is pulled from high to low, it indicates that the wiring of the new energy grid-connected installation device is correct; otherwise, the wiring has failed, and the result is displayed on the computer. This invention, by setting up detection signal injection relay expansion boards and detection signal reading relay expansion boards, injects detection signals in segments to determine the accuracy of the new energy grid-connected installation and accurately locates incorrect wiring positions.

[0021] The power supply in this invention includes a DC12V DC power supply and a DC5V step-down chip. The positive terminal of the DC12V DC power supply is connected to the positive input terminal of the DC5V step-down chip, the negative terminal of the DC12V DC power supply is connected to the negative input terminal of the DC5V step-down chip, the positive output terminal of the DC5V step-down chip is connected to the input terminal of the first DC5V relay, and the negative output terminal of the DC5V step-down chip is grounded, thereby reducing the DC12V voltage to DC5V, enabling the detection device to operate normally.

[0022] In this invention, the A-phase, B-phase, C-phase, and N-phase input terminals of the first DC5V relay are all connected to the positive output terminal of the DC5V step-down chip. The A-phase output terminal of the first DC5V relay is connected to the A-phase input terminals of all relay units on the detection signal injection relay expansion board. The B-phase output terminal of the first DC5V relay is connected to the B-phase input terminals of all relay units on the detection signal injection relay expansion board. The C-phase output terminal of the first DC5V relay is connected to the C-phase input terminals of all relay units on the detection signal injection relay expansion board. The N-phase output terminal of the first DC5V relay is connected to the N-phase input terminals of all relay units on the detection signal injection relay expansion board. Each relay unit on the detection signal injection relay expansion board is connected to the access signal interface on the new energy grid-connected metering installation device. The detection signal injection relay expansion board enables access signals to be injected into all access signal interfaces on the new energy grid-connected metering installation device.

[0023] In this invention, the input terminal of each relay unit on the detection signal reading relay expansion board is connected to the receiving signal interface on the new energy grid-connected metering installation device. The A-phase output terminals of all relay units on the detection signal reading relay expansion board are connected to the A-phase input terminal of the second DC5V relay. Similarly, the B-phase output terminals of all relay units on the detection signal reading relay expansion board are connected to the B-phase input terminal of the second DC5V relay, the C-phase output terminals of all relay units on the detection signal reading relay expansion board are connected to the C-phase input terminal of the second DC5V relay, and the N-phase output terminals of all relay units on the detection signal reading relay expansion board are connected to the N-phase input terminal of the second DC5V relay. This detection signal reading relay expansion board enables all receiving signal interfaces on the new energy grid-connected metering installation device to be injected with receiving signals.

[0024] The A-phase output, B-phase output, C-phase output, and N-phase output of the second DC5V relay are each connected to the sampling terminal of a digital switch sampling circuit.

[0025] In this invention, the microcontroller chip is model MB9BF218SPMC. Each KK terminal of the microcontroller chip is connected to either the signal terminal of a relay unit on the relay expansion board for injecting detection signals or the signal terminal of a relay unit on the relay expansion board for reading detection signals, thus controlling the conduction of the relay unit. Each SEL_K terminal of the microcontroller chip is connected to either the signal terminal of the first DC5V relay or the signal terminal of the second DC5V relay, allowing the microcontroller to select one input signal, which flows through the wiring on the new energy grid-connected metering installation device to another received signal for judgment. Each XK terminal of the microcontroller chip is connected to the signal terminal of the digital switch sampling circuit to determine whether the wiring on the new energy grid-connected metering installation device is correct. This invention improves detection accuracy by injecting detection signals in segments.

[0026] Each relay unit of the detection signal injection relay expansion board or detection signal reading relay expansion board consists of four relays connected in parallel. The signal terminal drive circuit of each relay is as follows: Figure 2 Each resistor includes: a first resistor R1, a second resistor R2, a third resistor R3, a first transistor T1, a second transistor T2, and a first diode D1. One end of the first resistor R1 is connected to the SEL_K terminal of the microcontroller. The other end of the first resistor R1 is connected to one end of the second resistor R2 and the base of the first transistor T1. The other end of the second resistor R2 and one end of the third resistor R3 are both connected to a 5V voltage. The other end of the third resistor R3 and the collector of the first transistor T1 are both connected to the base of the second transistor T2. The first diode D1 is used as a reverse voltage regulator. The anode of the first diode D1 is connected to the collector of the second transistor T2 and the negative terminal of the relay. The cathode of the first diode D1 is connected to a 12V voltage and the positive terminal of the relay. The emitters of the first transistor T1 and the second diode T2 are both grounded. The switching between the first transistor T1 and the second transistor T2 can control the closing and normally open states of the relay. When the microcontroller sends a high level to the relay pin, the controlled relay is in a normally open state; when the microcontroller sends a low level to the relay pin, the controlled relay is in a closed state.

[0027] like Figure 3The digital signal switching sampling circuit includes: a fourth resistor R4, a fifth resistor R5, a sixth resistor R6, an adjustable resistor R7, a second diode D2, a TLP785 optocoupler U, and a capacitor C. One end of the fourth resistor R4 is connected to the power supply voltage VCC, and the other end of the fourth resistor R4 is connected to the anode of the second diode D2. One end of the fifth resistor R5 serves as the signal terminal of the digital signal switching sampling circuit. The other end of the fifth resistor R5 and the cathode of the second diode D2 are both connected to the C1 terminal of the TLP785 optocoupler U. The E1 terminal and K1 terminal of the TLP785 optocoupler U, and one end of the capacitor C are all grounded. The A1 terminal of the TLP785 optocoupler U is connected to the other end of the capacitor C and one end of the sixth resistor R6. The other end of the sixth resistor R6 and one end of the varistor R7 are both connected to the output terminal of the second DC5V relay. The other end of the varistor R7 is grounded. The sixth resistor R6 serves as a current limiter. When a DC5V voltage is injected into one access port of the new energy grid-connected metering installation device, and connected to another receiving port via a banana test lead, the DC5V voltage is detected. At this time, the DC5V voltage enters from the A1 terminal of the TLP785 optocoupler U through the sixth resistor R6 in series, and exits from the K1 terminal to ground, forming an electrical loop. The C1 and E1 terminals of the TLP785 optocoupler U are connected, and the XK terminal of the microcontroller changes from high level to low level, indicating that the corresponding wiring on the new energy grid-connected metering installation device is connected.

[0028] In this invention, the communication chip is model SN65HVD2082ED. The TXD transmitting port of the communication chip is connected to the USRAT_RX port of the microcontroller chip, and the RXD receiving port of the communication chip is connected to the USRAT_TX port of the microcontroller chip. The 485-A port and 485-B port of the communication chip are connected to the computer through a serial port server, thereby realizing communication between the microcontroller and the computer through the UART communication protocol of the microcontroller, and realizing human-computer interaction.

[0029] The specific working process of this utility model's new energy grid-connected metering installation and testing device is as follows:

[0030] (1) All ports on the new energy grid-connected metering installation device are connected to the correct two ports A to A, B to B, C to C, and N to N through banana test wires, so that all devices on the new energy grid-connected metering installation device are connected in series or in parallel to form a complete photovoltaic new energy grid-connected installation wiring electrical circuit.

[0031] (2) After the operator connects the new energy grid-connected metering installation device according to the specified wiring method, the wiring test is performed by the detection device of this utility model. The computer sends a self-test command to the microcontroller. The command is converted by the serial port server and transmitted to the microcontroller through the 485 communication chip. The microcontroller is used to control the conduction of the detection signal injection relay expansion board and the detection signal reading relay expansion board. The microcontroller controls the signal interface on the first DC5V relay to conduct. The input signal of the corresponding signal interface on the detection signal injection relay expansion board flows through the wiring on the new energy grid-connected metering installation device to the corresponding signal interface on the detection signal reading relay expansion board. Then, the received signal is read through the corresponding signal interface on the second DC5V relay. The read received signal is converted into a digital signal through the digital quantity switch sampling circuit and transmitted to the microcontroller. If the detection signal in the microcontroller is pulled from high level to low level, it means that the wiring of the new energy grid-connected installation device is correct; otherwise, the wiring of the new energy grid-connected installation device fails, and the wiring result of the new energy grid-connected installation device is displayed on the computer.

[0032] The above are merely preferred embodiments of this utility model. The protection scope of this utility model is not limited to the above embodiments. All technical solutions falling within the scope of this utility model's concept are protected by this invention. It should be noted that for those skilled in the art, any improvements and modifications made without departing from the principle of this utility model should be considered within the protection scope of this utility model.

Claims

1. A detection device for metering installation of new energy grid-connected systems, characterized in that, include: The system includes a power supply, a microcontroller chip, a communication chip, a detection signal injection relay expansion board, a detection signal reading relay expansion board, a digital switch sampling circuit, a first DC5V relay, a second DC5V relay, and a computer. After the new energy grid-connected installation device is wired, the power supply powers the microcontroller chip. The microcontroller controls the conduction of the detection signal injection relay expansion board and the detection signal reading relay expansion board. The detection signal injection relay expansion board sends the access signal from the new energy grid-connected installation device, and the detection signal reading relay expansion board receives the received signal from the new energy grid-connected installation device. The microcontroller controls the second DC5V relay. When the signal interface on a DC5V relay is turned on, the input signal injected into the corresponding signal interface on the relay expansion board flows through the wiring on the new energy grid-connected metering installation device to the corresponding signal interface on the relay expansion board for detection signal reading. Then, the received signal is read through the corresponding signal interface on the second DC5V relay. The read received signal is converted into a digital signal by the digital quantity switch sampling circuit and transmitted to the microcontroller. If the detection signal in the microcontroller is pulled from high level to low level, it indicates that the wiring of the new energy grid-connected installation device is correct; otherwise, the wiring of the new energy grid-connected installation device has failed, and the wiring result of the new energy grid-connected installation device is displayed on the computer.

2. The detection device for grid-connected metering installation of new energy sources according to claim 1, characterized in that, The power supply includes a DC12V DC power supply and a DC5V step-down chip. The positive terminal of the DC12V DC power supply is connected to the positive input terminal of the DC5V step-down chip, the negative terminal of the DC12V DC power supply is connected to the negative input terminal of the DC5V step-down chip, the positive output terminal of the DC5V step-down chip is connected to the input terminal of a first DC5V relay, and the negative output terminal of the DC5V step-down chip is grounded.

3. The detection device for grid-connected metering installation of new energy sources according to claim 2, characterized in that, The A-phase, B-phase, C-phase, and N-phase input terminals of the first DC5V relay are all connected to the positive output terminal of the DC5V step-down chip. The A-phase output terminal of the first DC5V relay is connected to the A-phase input terminal of all relay units on the detection signal injection relay expansion board. The B-phase output terminal of the first DC5V relay is connected to the B-phase input terminal of all relay units on the detection signal injection relay expansion board. The C-phase output terminal of the first DC5V relay is connected to the C-phase input terminal of all relay units on the detection signal injection relay expansion board. The N-phase output terminal of the first DC5V relay is connected to the N-phase input terminal of all relay units on the detection signal injection relay expansion board. Each relay unit on the detection signal injection relay expansion board is connected to the access signal interface on the new energy grid-connected metering installation device.

4. The detection device for grid-connected metering installation of new energy sources according to claim 3, characterized in that, The input terminal of each relay unit on the detection signal reading relay expansion board is connected to the signal receiving interface on the new energy grid-connected metering installation device. The A-phase output terminal of all relay units on the detection signal reading relay expansion board is connected to the A-phase input terminal of the second DC5V relay. The B-phase output terminal of all relay units on the detection signal reading relay expansion board is connected to the B-phase input terminal of the second DC5V relay. The C-phase output terminal of all relay units on the detection signal reading relay expansion board is connected to the C-phase input terminal of the second DC5V relay. The N-phase output terminal of all relay units on the detection signal reading relay expansion board is connected to the N-phase input terminal of the second DC5V relay.

5. The detection device for grid-connected metering installation of new energy sources according to claim 4, characterized in that, The A-phase output terminal, B-phase output terminal, C-phase output terminal and N-phase output terminal of the second DC5V relay are respectively connected to the sampling terminal of a digital quantity switch sampling circuit.

6. The detection device for grid-connected metering installation of new energy sources according to claim 5, characterized in that, The microcontroller chip is model MB9BF218SPMC. Each KK terminal of the microcontroller chip is connected to the signal terminal of a relay unit on the detection signal injection relay expansion board or the signal terminal of a relay unit on the detection signal reading relay expansion board. Each SEL_K terminal of the microcontroller chip is connected to the signal terminal of the first DC5V relay or the signal terminal of the second DC5V relay. Each XK terminal of the microcontroller chip is connected to the signal terminal of the digital quantity switch sampling circuit.

7. The detection device for grid-connected metering installation of new energy sources according to claim 6, characterized in that, Each relay unit of the detection signal injection relay expansion board or the detection signal reading relay expansion board consists of four relays connected in parallel. The signal terminal drive circuit of each relay includes: a first resistor R1, a second resistor R2, a third resistor R3, a first transistor T1, a second transistor T2, and a first diode D1. One end of the first resistor R1 is connected to the SEL_K terminal of the microcontroller. The other end of the first resistor R1 is connected to one end of the second resistor R2 and the base of the first transistor T1. The other end of the second resistor R2 and one end of the third resistor R3 are both connected to a 5V voltage. The other end of the third resistor R3 and the collector of the first transistor T1 are both connected to the base of the second transistor T2. The anode of the first diode D1 is connected to the collector of the second transistor T2 and the cathode of the relay. The cathode of the first diode D1 is connected to a 12V voltage and the anode of the relay. The emitters of the first transistor T1 and the second diode T2 are both grounded.

8. The detection device for grid-connected metering installation of new energy sources according to claim 6, characterized in that, The digital quantity switch sampling circuit includes: a fourth resistor R4, a fifth resistor R5, a sixth resistor R6, a varistor R7, a second light-emitting diode D2, a TLP785 optocoupler U, and a capacitor C. One end of the fourth resistor R4 is connected to the power supply voltage VCC, and the other end of the fourth resistor R4 is connected to the anode of the second light-emitting diode D2. One end of the fifth resistor R5 serves as the signal terminal of the digital quantity switch sampling circuit. The other end of the fifth resistor R5 and the cathode of the second light-emitting diode D2 are both connected to the C1 terminal of the TLP785 optocoupler U. The E1 terminal, K1 terminal, and one end of the capacitor C of the TLP785 optocoupler U are all grounded. The A1 terminal of the TLP785 optocoupler U is connected to the other end of the capacitor C and one end of the sixth resistor R6. The other end of the sixth resistor R6 and one end of the varistor R7 are both connected to the output terminal of the second DC5V relay. The other end of the varistor R7 is grounded.

9. The detection device for grid-connected metering installation of new energy sources according to claim 6, characterized in that, The communication chip is model SN65HVD2082ED. The TXD transmitting port of the communication chip is connected to the USRAT_RX port of the microcontroller chip, and the RXD receiving port of the communication chip is connected to the USRAT_TX port of the microcontroller chip.

10. The detection device for grid-connected metering installation of new energy sources according to claim 9, characterized in that, The 485-A and 485-B ports of the communication chip are connected to the computer via a serial port server.

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