Isolation communication circuit for sampling voltage outside charging pile

Abstract

The utility model discloses an isolation communication circuit used for sampling voltage outside a charging pile. The isolation communication circuit used for sampling voltage outside the charging pile comprises a metering sampling module, an isolation communication module and an MCU unit. Wherein one side of the metering sampling module is used for being connected with the outer side of the charging controller of the direct-current charging pile, and is used for sampling the voltage outside the charging controller of the direct-current charging pile; one side of the isolation communication module is connected with the other side of the metering sampling module, and the other side of the isolation communication module is connected with the MCU unit; the voltage outside the charging controller of the direct current charging pile is isolated by the isolation communication module and then is sent to the MCU unit; an instruction of the MCU unit is isolated by the isolation communication module and then is sent to the metering sampling module. According to the technical scheme provided by the utility model, the problems of unstable external voltage high-temperature communication, large size and high production cost of the charging controller of the direct-current charging pile are solved.

Description

Technical Field

[0001] The utility model relates to the technical field of DC charging piles, in particular to an isolation communication circuit for sampling the voltage outside a charging pile. Background Art

[0002] As new energy electric vehicles enter a period of rapid development, the various charging equipment and charging stations that support them are becoming increasingly popular and widely available. Charging stations, as the most critical charging system for electric vehicles, generally utilize high voltage and high current. They are also equipped with corresponding charge controllers, and sampling outside the charge controller requires isolated communication. Existing isolated communication solutions typically use an isolated power supply coupled with an optocoupler. The drawbacks of this solution are: first, the large space required for the isolated power supply makes it difficult to adapt to the trend of miniaturized charging stations; second, communication stability is poor at high temperatures, posing safety risks; and third, the product requires numerous components, resulting in high overall costs. Utility Model Content

[0003] In order to overcome the shortcomings of the existing technology, an isolated communication circuit for voltage sampling outside a charging pile is proposed.

[0004] An isolated communication circuit for sampling the voltage outside a charging pile, comprising a metering sampling module, an isolated communication module and an MCU unit; wherein,

[0005] One side of the metering sampling module is used to be connected to the outside of the DC charging pile charging controller and to sample the voltage outside the DC charging pile charging controller;

[0006] One side of the isolated communication module is connected to the other side of the metering sampling module, and the other side of the isolated communication module is connected to the MCU unit;

[0007] The voltage outside the DC charging pile charging controller is isolated by the isolation communication module and then sent to the MCU unit; the instructions of the MCU unit are isolated by the isolation communication module and then sent to the metering sampling module.

[0008] Preferably, the metering sampling module includes an AC / DC single-phase metering IC and a sampling circuit connected thereto; the sampling circuit is connected to the outside of the DC charging pile charging controller, and a plurality of voltage-dividing series resistors are arranged between the two.

[0009] Preferably, the isolated communication module includes an isolated communication IC; the power supply of the AC / DC single-phase metering IC is obtained from a preset pin of the isolated communication IC through multiple filter capacitors.

[0010] Preferably, a crystal oscillator is provided between the 1st and 16th pins of the AC / DC single-phase metering IC.

[0011] Preferably, a first capacitor and a second capacitor are further provided between the crystal oscillator and the ground.

[0012] Preferably, the multiple filter capacitors include a third capacitor and a fourth capacitor connected in parallel.

[0013] Preferably, an ESD electrostatic diode is provided in parallel with the third capacitor and the fourth capacitor.

[0014] Preferably, the isolated communication IC is powered by a preset DC power supply end, and the supply voltage of the preset DC power supply end is 5V.

[0015] Preferably, the isolation communication IC is connected to the AC / DC single-phase metering IC via a serial port pin.

[0016] This utility model provides an isolated communication circuit for sampling the voltage outside a charging pile. This circuit collects voltage through a metering and sampling module and transmits it to the MCU unit for detection, conversion, and calculation. Simultaneously, instructions sent by the MCU unit also communicate with the metering and sampling module through the isolated communication module. This solution has a simple circuit design and stable communication performance. Compared with existing technologies, it solves the problem of unstable communication at high temperatures outside the DC charging pile "charging controller," reducing safety risks. Furthermore, its compact size and minimal footprint not only reduce overall costs but also adapt to the trend of miniaturization of charging piles. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a framework diagram of an isolated communication circuit for sampling the voltage outside a charging pile in an embodiment of the present utility model;

[0018] Figure 2 This is a circuit diagram of the metering sampling module in the embodiment of the present utility model;

[0019] Figure 3 This is a schematic diagram of the circuit used in the embodiment of the present utility model;

[0020] Figure 4 This is a circuit schematic diagram of the isolated communication module in an embodiment of the present utility model. DETAILED DESCRIPTION

[0021] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0022] Provide an isolated communication circuit for sampling the voltage outside the charging pile, such as Figures 1 to 4As shown, it includes a metering sampling module, an isolation communication module and an MCU unit; wherein, the metering sampling module is used to implement voltage sampling, one side of which is used to connect to the outside of the DC charging pile charging controller to sample the voltage outside the DC charging pile charging controller, and the other side is connected to the isolation communication module, that is, to send the sampled voltage to the MCU unit.

[0023] The isolated communication module implements isolated communication and is located between the metering and sampling module and the MCU. One side of the module is connected to the other side of the metering and sampling module, which in turn is connected to the MCU. During operation, the voltage outside the DC charging pile controller is isolated by the isolated communication module before being sent to the MCU. Simultaneously, commands from the MCU are isolated by the isolated communication module before being sent to the metering and sampling module, thus achieving isolated communication.

[0024] Specifically, both the metering and sampling modules and the isolated communication module include their core ICs. For example, in one implementation, the metering and sampling module includes an AC / DC single-phase metering IC and a connected sampling circuit. The sampling circuit is connected to the outside of the DC charging pile controller, with multiple voltage-dividing series resistors interposed between the two. The isolated communication module also includes an isolated communication IC. The AC / DC single-phase metering IC is powered by a preset pin on the isolated communication IC and then by multiple filter capacitors.

[0025] Among them, such as Figure 3 As shown, the voltage divider series resistors include R174 (100Ω±1%) and R175 to R185 (470K±0.5%).

[0026] The AC / DC single-phase metering IC uses the RN8209C, and the isolated communication IC uses the CA-IS3621LVW. The CA-IS3621LVW offers high performance, including 5kVRMS isolation voltage resistance and integrated high-efficiency, low-radiation digital isolators with DC-DC converters. Its signal transmission rate ranges from DC to 100Mbps, and its isolation barrier lifespan is greater than 40 years at rated operating voltage. This solution offers low cost, stable communication, and a compact size, effectively preventing accidents.

[0027] In one implementation, Figure 2 As shown, a crystal oscillator HC-49SM is provided between the 1st and 16th pins of the AC / DC single-phase metering IC (RN8209C); at the same time, a first capacitor C165 and a second capacitor C166 are provided between the crystal oscillator and the ground.

[0028] In one implementation, Figure 4As shown, the multiple filter capacitors include a third capacitor C159 and a fourth capacitor C161 connected in parallel. Furthermore, an ESD diode ESD23 is provided in parallel with the third and fourth capacitors C159 and C161. The isolated communication IC is powered by a preset DC power supply terminal, which has a preset supply voltage of 5V. The isolated communication IC is connected to the AC / DC single-phase metering IC via serial port pins TX5 and RX5.

[0029] Based on the implementation scheme composed of RN8209C and CA-IS3621LVW, the circuit implementation principle mainly includes: the voltage outside the DC charging pile charging controller is divided by resistors R175, R176, R177, R178, R179, R180, R185, R184, R183, R182, and R181, and then connected in series with electronic R174 and capacitors C190 (10nF±10%, 50V) and C191. (100nF ±10%, 50V) to ground, then connected to pin 9 of the RN8209C for sampling. It then connects to pin 13 of the CA-IS3621LVW via pin 12 of the RN8209C for isolation. After isolation, it is sent to the MCU via pin 4 of the CA-IS3621LVW. The MCU, after isolation via pin 3 of the CA-IS3621LVW, sends instructions via its pin 14 to pin 13 of the RN8209C for reception. Simultaneously, the RN8209C is powered by capacitors C159 and C161 at pin 16 of the CA-IS3621LVW, filtered, and then supplied to the RN8209C, thus achieving bidirectional isolated power supply communication.

[0030] The above is an explanation of the isolated communication circuit for sampling the voltage outside the charging pile of the present invention, which is used to help understand the present invention; however, the implementation of the present invention is not limited to the above embodiments. Any changes, modifications, substitutions, combinations, and simplifications that do not deviate from the principles of the present invention should be equivalent replacement methods and are included in the scope of protection of the present invention.

Claims

1. An isolated communication circuit for sampling the voltage outside a charging pile, characterized in that: It includes a metering sampling module, an isolation communication module and an MCU unit; among which, One side of the metering sampling module is used to be connected to the outside of the DC charging pile charging controller and to sample the voltage outside the DC charging pile charging controller; One side of the isolated communication module is connected to the other side of the metering sampling module, and the other side of the isolated communication module is connected to the MCU unit; The voltage outside the DC charging pile charging controller is isolated by the isolation communication module and then sent to the MCU unit; the instructions of the MCU unit are isolated by the isolation communication module and then sent to the metering sampling module.

2. The isolated communication circuit for sampling the voltage outside the charging pile according to claim 1, characterized in that: The metering sampling module includes an AC / DC single-phase metering IC and a sampling circuit connected thereto; the sampling circuit is connected to the outside of the DC charging pile charging controller, and a plurality of voltage-dividing series resistors are arranged between the two.

3. The isolated communication circuit for sampling the voltage outside the charging pile according to claim 2, characterized in that: The isolated communication module includes an isolated communication IC; the AC / DC single-phase metering IC is powered by a preset pin of the isolated communication IC through a plurality of filter capacitors.

4. The isolated communication circuit for sampling the voltage outside the charging pile according to claim 3, characterized in that: A crystal oscillator is provided between the 1st and 16th pins of the AC / DC single-phase metering IC.

5. The isolated communication circuit for sampling the voltage outside the charging pile according to claim 4, characterized in that: A first capacitor and a second capacitor are further provided between the crystal oscillator and the ground.

6. The isolated communication circuit for sampling the voltage outside the charging pile according to claim 5, characterized in that: The plurality of filter capacitors include a third capacitor and a fourth capacitor connected in parallel.

7. The isolated communication circuit for sampling the voltage outside the charging pile according to claim 6, characterized in that: An ESD electrostatic diode is provided in parallel with the third capacitor and the fourth capacitor.

8. The isolated communication circuit for sampling the voltage outside the charging pile according to claim 3, characterized in that: The isolated communication IC is powered by a preset DC power supply terminal, and the power supply voltage of the preset DC power supply terminal is 5V.

9. The isolated communication circuit for sampling the voltage outside the charging pile according to claim 3, characterized in that: The isolation communication IC is connected to the AC / DC single-phase metering IC via a serial port pin.

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