A power supply circuit for geothermal metering, a geothermal metering unit, and an AC charging pile.

Abstract

This utility model discloses a thermal ground metering power supply circuit, a thermal ground metering unit, and an AC charging pile. The thermal ground metering power supply circuit includes an isolated power supply unit and an isolation transformer. The input terminal of the isolated power supply unit is connected to the input voltage, and the output terminal of the isolated power supply unit is connected to the input terminal of the isolation transformer. The output terminal of the isolation transformer is connected to a rectifier unit to output a working voltage to the thermal ground metering circuit to be powered. The technical solution provided by this utility model solves the problem of capacitor damage in RC step-down circuits operating in complex environments through the combination of an isolated power supply and an isolation transformer. Furthermore, it can be applied to 7KW AC charging piles, not only avoiding the problem of easy damage to step-down circuits but also exhibiting good control performance and stable operation without abnormalities.

Description

Technical Field

[0001] This utility model relates to AC charging piles, and in particular to a thermal ground metering power supply circuit, a thermal ground metering unit, and an AC charging pile. Background Technology

[0002] The thermal metering circuit in a charging pile is mainly used to monitor the operating temperature of the equipment to ensure that all components in the charging pile are within a safe operating range and to avoid safety malfunctions caused by overheating. Currently, most 7KW AC charging piles on the market use a resistor-capacitor step-down method to power the thermal metering circuit. However, although this circuit is economical, the step-down capacitor is at risk of damage when operating in complex environments, posing a safety hazard to the safe operation of the charging pile. Utility Model Content

[0003] To overcome the shortcomings of existing technologies, this utility model provides a thermal ground metering power supply circuit, a thermal ground metering unit, and an AC charging pile.

[0004] A thermal ground metering power supply circuit includes an isolation power supply unit and an isolation transformer; the input terminal of the isolation power supply unit is used to connect to an input voltage, and the output terminal of the isolation power supply unit is connected to the input terminal of the isolation transformer; the output terminal of the isolation transformer is connected to a rectifier unit to output a working voltage to the thermal ground metering circuit to be powered.

[0005] A thermal ground metering unit includes a thermal ground metering power supply circuit as described above, wherein the overall input terminal of the thermal ground metering unit is connected to the operating voltage output by the thermal ground metering power supply circuit.

[0006] An AC charging pile includes a thermal metering power supply circuit as described above, or a thermal metering unit as described above.

[0007] This invention provides a thermal ground metering power supply circuit, a thermal ground metering unit, and an AC charging pile. The isolated power supply unit is compatible with 3V~6V applications and can clamp and limit the power transistor current when the current is too high, ensuring its own operation within a safe range and protecting external components from high current surges. Simultaneously, a dead time tBBM is designed between the two drives of the isolated power supply unit, avoiding common current issues and reducing the drain-source voltage when the power transistor is turned on, thus reducing switching losses. The isolation transformer can achieve 3.3V-5V input and 3.3V-5V output, suitable for unregulated power supply solutions with a power rating not exceeding 2W. The combination of the isolated power supply and isolation transformer solves the problem of step-down capacitor damage in complex environments. Compared with existing technologies, the thermal ground metering power supply circuit and corresponding thermal ground metering unit and AC charging pile solution provided by this invention can be applied to 7KW AC charging piles, not only avoiding the problem of easy damage to step-down capacitors but also exhibiting good control performance and stable operation without abnormalities. Attached Figure Description

[0008] Figure 1 This is a framework diagram of the isolated power supply in an embodiment of this utility model;

[0009] Figure 2 This is a circuit diagram of the power supply circuit for thermal ground metering in an embodiment of this utility model. Detailed Implementation

[0010] To make the technical problems, technical solutions, and beneficial effects of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present utility model and are not intended to limit the present utility model.

[0011] Provide a power supply circuit for thermal ground metering, such as Figure 1 As shown, it includes an isolation power supply unit and an isolation transformer; the input terminal of the isolation power supply unit is used to connect to the input voltage, and the output terminal of the isolation power supply unit is connected to the input terminal of the isolation transformer; the output terminal of the isolation transformer is connected to the rectifier unit and outputs the working voltage to the thermal ground metering circuit to be powered.

[0012] The isolation power supply unit and isolation transformer can be integrated into a single chip. For example, the isolation power supply unit can use the VPS8702 / S. The VPS8702 / S is a DC-DC isolated switching power supply integrated controller suitable for full-bridge topology. Its bridge drive method has fewer transformer windings, lower cost, and can meet applications from 3V to 6V, offering strong compatibility. When the current is too high, the clamp limits the power transistor current, ensuring that the chip itself operates in a safe area and protecting external devices from high current surges. Furthermore, the VPS8702 / S incorporates a dead time tBBM between the two drives, preventing common-mode operation and reducing the drain-source voltage when the power transistor is turned on, thus minimizing switching losses.

[0013] The isolation transformer used is VPT87BB-01B, which has an isolation voltage of up to 3000VDC. It can realize 3.3V-5V input and 3.3V-5V output, as well as unregulated power supply solutions with a power of no more than 2W. It can be combined with VPS8702 / S for isolated power supply scenarios.

[0014] The output of the isolation transformer, after rectification, supplies power to the thermal ground metering circuit, i.e., it outputs the operating voltage to the thermal ground metering circuit. For example, the rectifier unit includes two Schottky diodes connected in parallel.

[0015] In a typical implementation, such as Figure 2As shown, the isolated power supply unit U44 uses a VPS8702, and the isolation transformer T4 uses a VPT87BB-01B. The input terminals of U44 include an input pin VIN, a ground pin GND, a clock pin CLK, and an enable pin EN. VIN is connected to the VDD_5V input; a first capacitor C23 (4.7uF, ±20%, 25V) is placed between VDD_5V and GND. The output terminals of the isolated power supply unit include two drive output pins, VD1 and VD2. The EN pin is used to control the chip's on / off state. When EN is pulled high (it is automatically pulled high when floating), U44 operates normally; when EN is pulled low, U44 stops working, achieving ultra-low standby power consumption.

[0016] Pins 1, 2, 3, and 4 of isolation transformer T4 are inputs, and pins 5, 6, 7, and 8 are outputs. The output of isolation transformer T4 is connected to two Schottky diodes, D23 and D24, model B5819W, and outputs 5V_DC to power the thermal ground metering circuit to be powered.

[0017] A thermal ground metering unit is provided, including the aforementioned thermal ground metering power supply circuit, wherein the overall input terminal of the thermal ground metering unit is connected to the operating voltage output by the thermal ground metering power supply circuit.

[0018] In a typical implementation, such as Figure 2 As shown, the thermal ground metering unit includes a low-dropout linear regulator U606, model SE8233X2-HF. The low-dropout linear regulator U606 includes an input pin VIN, an output pin VOUT, and an output pin VSS. The input pin VIN is connected between the 5V_DC operating voltage output from the thermal ground metering power supply circuit and the differential signal ground terminal RNGND, and is connected in parallel with a second capacitor C24 (4.7uF, ±20%, 25V), a third capacitor C694 (100nF, ±10%, 50V), and a first resistor R92 (510Ω ±5%).

[0019] Furthermore, the output pin VOUT of the low-dropout linear regulator is used to provide the output voltage D3V3. A second resistor R231 (10Ω, ±1%) is connected in series with the differential signal ground terminal RNGND. Then, a fourth capacitor C280 (10uF, ±20%, 25V), a fifth capacitor C218 (100nF, ±10%, 50V), a sixth capacitor C217 (10uF, ±20%, 25V), and a seventh capacitor C216 (100nF, ±10%, 50V) are connected in parallel. The VSS pin of the low-dropout linear regulator is connected to the differential signal ground terminal RNGND.

[0020] Understandably, the thermal metering unit is not limited to the above-mentioned components.

[0021] An AC charging pile is provided, including the above-mentioned thermal ground metering power supply circuit or a thermal ground metering unit based on the above-mentioned thermal ground metering power supply circuit, and other prior art parts of the AC charging pile will not be described here.

[0022] The above is a description of the present utility model, which is used to help understand the present utility model. However, the implementation of the present utility model is not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the principle of the present utility model shall be considered as equivalent substitutions and shall be included within the protection scope of the present utility model.

Claims

1. A thermal metering power supply circuit, characterized by, It includes an isolation power supply unit and an isolation transformer; the input terminal of the isolation power supply unit is used to connect to the input voltage, and the output terminal of the isolation power supply unit is connected to the input terminal of the isolation transformer; the output terminal of the isolation transformer is connected to a rectifier unit to output a working voltage to the thermal ground metering circuit to be powered.

2. The hot earth metered power supply circuit of claim 1, wherein, The rectifier unit includes two Schottky diodes connected in parallel.

3. The hot earth metered power supply circuit of claim 2, wherein, The input terminal of the isolated power supply unit includes an input pin, a ground pin, a clock pin, and an enable pin; the output terminal of the isolated power supply unit includes two drive output pins; a first capacitor is connected between the input pin and the ground pin.

4. The hot-spot metered power supply circuit of claim 3, wherein, The input range of the isolation transformer is 3.3V-5V, and the output range of the isolation transformer is 3.3V-5V.

5. A thermal ground metering unit, characterized in that, Includes the thermal ground metering power supply circuit as described in claim 4, wherein the overall input terminal of the thermal ground metering unit is connected to the operating voltage output by the thermal ground metering power supply circuit.

6. The heat metering unit of claim 5, wherein, The device includes a low-dropout linear regulator, which has an input pin, an output pin, and a VSS pin. The input pin of the low-dropout linear regulator is connected between the operating voltage output by the thermal ground metering power supply circuit and the differential signal ground terminal, and is connected in parallel with a second capacitor, a third capacitor, and a first resistor.

7. The heat metering unit of claim 6, wherein, The low-dropout linear regulator is used to provide the output voltage, and a second resistor is connected in series between the output pin of the low-dropout linear regulator and the ground terminal, followed by a fourth capacitor, a fifth capacitor, a sixth capacitor, and a seventh capacitor connected in parallel.

8. The heat metering unit of claim 7, wherein, The VSS pin of the low-dropout linear regulator is connected to the grounding terminal.

9. An alternating current charging post, characterized in that, It includes the thermal ground metering power supply circuit as described in any one of claims 1 to 4, or the thermal ground metering unit as described in any one of claims 5 to 8.

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