Power relay power consumption control circuit and alternating current charging pile
By using the output signal of the MCU control unit and combining it with a series circuit of transistors and resistors, efficient control of the power relay is achieved, solving the problem of continuous heating of the current-limiting resistor and reducing the temperature rise of the charging pile.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- SHENZHEN QIHUI ELECTRIC CO LTD
- Filing Date
- 2025-08-14
- Publication Date
- 2026-07-24
AI Technical Summary
In existing technologies, the current-limiting resistor continuously heats up during power relay control, leading to increased temperature rise in the charging pile and the overheating problem remains unresolved.
The system uses an MCU control unit to output high-level, low-level, and periodic frequency signals. The high-level signal controls the pulse output, reducing the power consumption of the relay. Combined with a series circuit of transistors and resistors, it enables the closing and opening control of the power relay.
It effectively reduces the power consumption of the relay, solves the problem of continuous heat generation of the current-limiting resistor, and reduces the temperature rise of the charging pile.
Smart Images
Figure CN224555474U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to AC charging piles, and in particular to a power relay power consumption control circuit and an AC charging pile. Background Technology
[0002] With the popularization of new energy vehicles, charging pile technology is also developing rapidly. Power relays are an indispensable component in 22kW AC charging piles, and also a major heat source. Currently, most methods to reduce power relay control power consumption use resistor current limiting, essentially shifting the relay's heat generation to the current-limiting resistor. However, this solution still causes the current-limiting resistor to continue heating when the relay is closing, increasing the charging pile's temperature rise; therefore, the heat generation problem has not yet been effectively solved. Utility Model Content
[0003] To overcome the shortcomings of the prior art, this utility model provides a power relay power consumption control circuit and an AC charging pile.
[0004] A power relay power consumption control circuit includes an MCU control unit and one or more power relays electrically connected to the MCU control unit; when there are multiple power relays, the multiple power relays are electrically connected to the MCU unit in parallel; a first resistor and a transistor are connected in series between the MCU control unit and a single power relay; an output pin of the MCU control unit is used to output a high-level signal, a low-level signal, and a periodic frequency signal to the power relay through the resistor and the transistor.
[0005] Preferably, the transistor is an NPN silicon transistor.
[0006] Preferably, it further includes a first capacitor and a second resistor connected in parallel; one end of the first capacitor and the second resistor is connected between the first resistor and the transistor, and the other end of the first capacitor and the second resistor is connected to ground.
[0007] Preferably, the number of power relays is four, and the power supply voltage of each relay is a DC power supply voltage of 12V.
[0008] Preferably, the parameters of the first resistor are 1kΩ ± 1%.
[0009] Preferably, the parameters of the second resistor are 10kΩ ± 1%.
[0010] Preferably, the parameters of the first capacitor are 100nF, ±10%, and 50V.
[0011] Preferably, the periodic frequency signal is an output frequency of 17kHz and a 50% duty cycle signal.
[0012] Preferably, the high-level signal is used to control the power relay to close, the periodic frequency signal is used to lock the power relay, and the low-level signal is used to control the power relay to open.
[0013] An AC charging station includes a power relay power consumption control circuit as described above.
[0014] The power relay power consumption control circuit and AC charging pile provided by this utility model are based on the following principle: the MCU control unit outputs high-level, low-level and periodic frequency signals to the power relay, and the high-level control is converted to pulse output control to reduce the power consumption of the relay, thus solving the problem of continuous heating of the current limiting resistor in the prior art. Attached Figure Description
[0015] Figure 1 This is a framework diagram of the power relay power consumption control circuit in an embodiment of this utility model;
[0016] Figure 2 This is a circuit diagram of the power relay power consumption control circuit in an embodiment of this utility model. Detailed Implementation
[0017] 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.
[0018] A power relay power consumption control circuit is provided to reduce the power consumption of the relay control operation. Its framework is as follows: Figure 1 As shown, it includes an MCU control unit and one or more power relays electrically connected to the MCU control unit; when there are multiple power relays, the multiple power relays are electrically connected to the MCU unit in parallel; a first resistor and a transistor are connected in series between the MCU control unit and a single power relay; an output pin of the MCU control unit is used to output a high-level signal, a low-level signal, and a periodic frequency signal to the power relay through the resistor and the transistor.
[0019] The MCU control unit uses a microcontroller, and the output pin of the microcontroller outputs signals to the power relay through a resistor and a transistor: a high-level signal is used to control the power relay to close, a periodic frequency signal is used to lock the power relay, and a low-level signal is used to control the power relay to open. That is, the power relay is controlled by the high-level control pulse output.
[0020] In one implementation, such as Figure 2As shown, the MCU control unit outputs high-level, low-level, and periodic frequency signals through the RELAY_EN pin. RLY1, RLY2, RLY3, and RLY4 correspond to four parallel power relays, with a DC supply voltage of 12V for each relay. Resistors R174, R189, R209, and R228 are the first resistors, with parameters of 1kΩ ±1%. Q17, Q19, Q21, and Q23 are transistors, preferably NPN silicon transistors SS8050. Resistors R177, R194, R212, and R240 are the second resistors, with parameters of 10kΩ ±1%. Capacitors C144, C151, C168, and C176 are the first capacitors, with parameters of 100nF ±10%, 50V (NC). The first capacitor and the second resistor are connected in parallel, with one end connected between the first resistor and the transistor, and the other end connected to ground. The periodic frequency signal is an output frequency of 17kHz with a 50% duty cycle.
[0021] During operation, the MCU control unit outputs a high level via RELAY_EN, which is connected to Q17 through resistor R174, Q19 through R189, Q21 through R209, and Q23 through R228, driving control relays RLY1, RLY2, RLY3, and RLY4 to close. After 100 milliseconds, the MCU control unit outputs a 17kHz 50% duty cycle signal via RELAY_EN to lock the relays. When it is necessary to open the circuit, the MCU control unit outputs a low level via RELAY_EN, which is then connected to Q17 through resistor R174, Q19 through R189, Q21 through R209, and Q23 through R228, driving control relays RLY1, RLY2, RLY3, and RLY4 to open the circuit, thus realizing power relay control.
[0022] An AC charging pile is provided, including the power relay power consumption control circuit described above. Other prior art aspects of AC charging piles will not be described here.
[0023] 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 power relay power consumption control circuit, characterized in that, The device includes an MCU control unit and one or more power relays electrically connected to the MCU control unit; when there are multiple power relays, the multiple power relays are electrically connected to the MCU control unit in parallel; a first resistor and a transistor are connected in series between the MCU control unit and a single power relay; an output pin of the MCU control unit is used to output a high-level signal, a low-level signal, and a periodic frequency signal to the power relay through the resistor and the transistor.
2. The power relay power consumption control circuit as described in claim 1, characterized in that, The transistor is an NPN silicon transistor.
3. The power relay power consumption control circuit as described in claim 2, characterized in that, It also includes a first capacitor and a second resistor connected in parallel; one end of the first capacitor and the second resistor is connected between the first resistor and the transistor, and the other end of the first capacitor and the second resistor is connected to ground.
4. The power relay power consumption control circuit as described in claim 3, characterized in that, The number of power relays is four, and all of them are powered by a DC power supply voltage of 12V.
5. The power relay power consumption control circuit as described in claim 4, characterized in that, The parameters of the first resistor are 1kΩ ± 1%.
6. The power relay power consumption control circuit as described in claim 5, characterized in that, The parameters of the second resistor are 10kΩ ± 1%.
7. The power relay power consumption control circuit as described in claim 6, characterized in that, The parameters of the first capacitor are 100nF, ±10%, 50V.
8. The power relay power consumption control circuit as described in any one of claims 1 to 7, characterized in that, The periodic frequency signal is an output frequency of 17kHz with a 50% duty cycle.
9. The power relay power consumption control circuit as described in claim 8, characterized in that, The high-level signal is used to control the power relay to close, the periodic frequency signal is used to lock the power relay, and the low-level signal is used to control the power relay to open.
10. An AC charging pile, characterized in that, Includes the power relay power consumption control circuit as described in any one of claims 1 to 9.