CN-224233705-U - Ethernet interface high-voltage isolation system based on intelligent ammeter

CN224233705UCN 224233705 UCN224233705 UCN 224233705UCN-224233705-U

Abstract

The utility model discloses an Ethernet interface high-voltage isolation system based on an intelligent ammeter, which comprises an Ethernet module, a primary isolation unit module and a secondary electrical isolation module, wherein the Ethernet module is connected with the primary isolation unit module and the secondary electrical isolation module.

Inventors

WANG DONGYANG
CHEN GUOHUA
ZHAO XIAOJIN
REN ZEJUN
LI XIAOJING
YU SHUOFENG

Assignees

杭州球一科技有限公司

Dates

Publication Date: 20260512
Application Date: 20250611

Claims (6)

1. The Ethernet interface high-voltage isolation system based on the intelligent ammeter is characterized by comprising an Ethernet module, a primary isolation unit module and a secondary electrical isolation module, wherein the Ethernet module is connected with the primary isolation unit module and the secondary electrical isolation module; the Ethernet module comprises an Ethernet chip and is used for converting Ethernet data into serial data; The primary isolation unit module comprises a network transformer which is connected with an RJ45 interface, and a center tap is grounded through a grounding capacitor; The second-level electric isolation module comprises an optical coupling isolation module which is connected with a serial port data pin of the Ethernet chip and the intelligent ammeter management chip; the optical coupler isolation module comprises a transmitting optical coupler and a receiving optical coupler, wherein the input end of the transmitting optical coupler is connected with the transmitting end of the central management chip through a current limiting resistor, and the output end of the transmitting optical coupler is connected with RXD1 of the Ethernet chip through a pull-up resistor; The input end of the receiving optocoupler is connected with TXD1 of the Ethernet chip through a current limiting resistor, and the output end of the receiving optocoupler is connected with the receiving end of the central management chip through a pull-up resistor.
2. The Ethernet interface high-voltage isolation system based on the intelligent ammeter according to claim 1, wherein the Ethernet module is internally provided with a 50Ω impedance matching resistor and a crystal oscillation capacitor; The device comprises an Ethernet chip U1, a capacitor, a resistor, a light emitting diode and a crystal oscillation capacitor Y1; Pins 3 and 8 of the Ethernet chip U1 are respectively connected with one end of a capacitor C3 and one end of a capacitor C4, and the other end of the capacitor C3 and the other end of the capacitor C4 are grounded; pins 6 and 7 of the Ethernet chip U1 are respectively connected with one end of a resistor R2 and one end of a resistor R1, the other end of the resistor R2 is connected with the negative electrode of a light emitting diode LED2, the positive electrode of the light emitting diode LED2 is connected with VCC voltage, the other end of the resistor R1 is connected with the negative electrode of the light emitting diode LED1, the positive electrode of the light emitting diode LED1 is connected with VCC voltage, pins 4 and 5 of the Ethernet chip U1 are respectively connected with two ends of a crystal oscillating capacitor Y1, pins 17 of the Ethernet chip U1 are grounded, pins 18 of the Ethernet chip U1 are connected with VCC voltage together with one ends of a capacitor C1 and a capacitor C2, the other ends of the capacitor C1 and the capacitor C2 are grounded, pins 8 of the Ethernet chip U1 are connected with one end of a resistor R7, and the other ends of the resistor R7 are connected with VCC voltage.
3. The Ethernet interface high voltage isolation system based on the intelligent ammeter according to claim 2, wherein the crystal oscillation capacitor Y1 is characterized in that the capacitor is configured according to a load: When the crystal load capacitance is 12pF, no external capacitance is configured; when the crystal load capacitor is 20pF, a 15pF external capacitor is configured, namely, two ends of the crystal oscillation capacitor Y1 are respectively connected with one end of the capacitor C5 and one end of the capacitor C6, and the other end of the capacitor C5 and the other end of the capacitor C6 are grounded.
4. The Ethernet interface high voltage isolation system based on the intelligent ammeter according to claim 1, wherein the primary isolation unit module comprises a network transformer T1, an RJ45 interface, a resistor and a capacitor; Pins 1, 2, 3 and 6 of the RJ45 interface are respectively connected with pins 16, 14, 11 and 9 of the network transformer T1, pins 4 and 5 of the RJ45 interface are connected with one end of a resistor R4, pins 7 and 8 of the RJ45 interface are connected with one end of a resistor R3, the other end of the resistor R4 and the other end of the resistor R3 are connected with one end of a capacitor C10, and the other end of the capacitor C10 is grounded; The pins 15 and 10 of the network transformer T1 are respectively connected with one end of a resistor R5 and one end of a resistor R6, the other end of the resistor R5 and the other end of the resistor R6 are connected with one end of a capacitor C10, the pins 2 and 7 of the network transformer T1 are respectively connected with one end of a capacitor C8 and one end of a capacitor C9, the other end of the capacitor C8 and the other end of the capacitor C9 are grounded, and the pins 1,3, 6 and 8 of the network transformer T1 are respectively connected with corresponding pins of an Ethernet chip.
5. The Ethernet interface high voltage isolation system based on the intelligent ammeter of claim 1, wherein the secondary electric isolation module comprises an optocoupler and a resistor; The No. 14 pin of the Ethernet chip U1 is connected with one end of a resistor R2, the other end of the resistor R2 is connected with the No. 2 pin of an optical coupler E10, the No. 1 pin of the optical coupler E10 is connected with VCC voltage, the No. 3 pin of the optical coupler E10 is grounded, the No. 4 pin of the optical coupler E10 is connected with 3.3V voltage and one end of the resistor R1, and the other end of the resistor R1 is connected with the RXD pin of the central management chip; The No. 13 pin of the Ethernet chip U1 is connected with one end of a resistor R4, the other end of the resistor R4 is connected with VCC voltage together with the No. 4 pin of an optical coupler E11, the No. 3 pin of the optical coupler E11 is grounded, the No. 1 pin of the optical coupler E11 is connected with one end of a resistor R3, the other end of the resistor R3 is connected with 3.3V voltage, the No. 2 pin of the optical coupler E11 is connected with one end of a resistor R5, and the other end of the resistor R2 is connected with the TXD pin of the central management chip.
6. The Ethernet interface high voltage isolation system based on the intelligent ammeter according to claim 5, wherein the working logic of the secondary electric isolation module is as follows: When the Ethernet chip U1 sends data, the receiving optocoupler E11 is conducted, and the central management chip receives the data; When the central management chip transmits data, the transmitting optical coupler E10 is conducted, and the Ethernet chip U1 receives the data.

Description

Ethernet interface high-voltage isolation system based on intelligent ammeter Technical Field The utility model relates to the technical field of electric energy meters, in particular to an Ethernet interface high-voltage isolation system based on an intelligent electric meter. Background The integration of the intelligent electric meter with the Ethernet port function is an important trend of development of intelligent power grids and the Internet of things (IoT), and the Ethernet port function has great advantages in high-speed data transmission, networked management and improvement of system compatibility. With the development of the electric power Internet of things and the energy Internet, an integrated, high-voltage-resistant and low-power-consumption isolation scheme becomes mainstream, and meanwhile, the communication efficiency and the system reliability are further optimized by combining the edge computing capability of the intelligent ammeter. The high-voltage isolation communication technology of the intelligent ammeter and the Ethernet port needs to be balanced between high-voltage security, high-speed data transmission and cost control. The current mainstream scheme mainly adopts single-stage magnetic isolation (network transformer) to realize high-voltage isolation, but has obvious defects that the network transformer has poor isolation effect on low-frequency surges (such as power frequency interference), the isolation withstand voltage level is usually not more than 2kV, high-voltage impact in a complex environment of a power grid is difficult to resist, the signal path between an Ethernet chip and an ammeter main control chip is not secondarily isolated, and a residual interference conduction path exists. Therefore, an ethernet interface scheme with multiple isolation mechanisms is needed, which can ensure high-speed data transmission and solve the potential electrical safety hazard of the smart meter in a high-voltage scene. Disclosure of utility model The utility model overcomes the defects of the prior art and provides the Ethernet interface high-voltage isolation system based on the intelligent ammeter with a multiple isolation mechanism. The technical scheme of the utility model is as follows: The Ethernet interface high-voltage isolation system based on the intelligent ammeter comprises an Ethernet module, a primary isolation unit module and a secondary electrical isolation module, wherein the Ethernet module is connected with the primary isolation unit module and the secondary electrical isolation module; the Ethernet module comprises an Ethernet chip and is used for converting Ethernet data into serial data; The primary isolation unit module comprises a network transformer which is connected with an RJ45 interface, and a center tap is grounded through a grounding capacitor; The second-level electric isolation module comprises an optical coupling isolation module which is connected with a serial port data pin of the Ethernet chip and the intelligent ammeter management chip; the optical coupler isolation module comprises a transmitting optical coupler and a receiving optical coupler, wherein the input end of the transmitting optical coupler is connected with the transmitting end of the central management chip through a current limiting resistor, and the output end of the transmitting optical coupler is connected with RXD1 of the Ethernet chip through a pull-up resistor; The input end of the receiving optocoupler is connected with TXD1 of the Ethernet chip through a current limiting resistor, and the output end of the receiving optocoupler is connected with the receiving end of the central management chip through a pull-up resistor. Furthermore, the Ethernet module is internally provided with a 50Ω impedance matching resistor and a crystal oscillation capacitor; The device comprises an Ethernet chip U1, a capacitor, a resistor, a light emitting diode and a crystal oscillation capacitor Y1; Pins 3 and 8 of the Ethernet chip U1 are respectively connected with one end of a capacitor C3 and one end of a capacitor C4, and the other end of the capacitor C3 and the other end of the capacitor C4 are grounded; pins 6 and 7 of the Ethernet chip U1 are respectively connected with one end of a resistor R2 and one end of a resistor R1, the other end of the resistor R2 is connected with the negative electrode of a light emitting diode LED2, the positive electrode of the light emitting diode LED2 is connected with VCC voltage, the other end of the resistor R1 is connected with the negative electrode of the light emitting diode LED1, the positive electrode of the light emitting diode LED1 is connected with VCC voltage, pins 4 and 5 of the Ethernet chip U1 are respectively connected with two ends of a crystal oscillating capacitor Y1, pins 17 of the Ethernet chip U1 are grounded, pins 18 of the Ethernet chip U1 are connected with VCC voltage together with one ends of a capacitor C1 and a capacitor C2,