Direct current charging pile field detector

Abstract

The utility model discloses a direct current charging pile field detector, which belongs to the technical field of charging piles and comprises a charging gun interface, an insulation detection module, a main control unit, an analog quantity detection unit, a battery simulator, a power supply module and a battery pack. According to the utility model, various detection functions including voltage, current, insulation and the like are integrated, the state of the direct current charging pile can be comprehensively monitored, the 485 communication module, the Bluetooth module and the LIN communication module are arranged, convenient communication with external equipment and a system is ensured, interoperability and compatibility of the system are enhanced, and the system is convenient to use. The safety of the system is improved by the independent insulation detection module and the optical coupler isolation circuit, reliable operation in a high-voltage environment is ensured, the voltage acquisition circuit and the current acquisition circuit adopt high-precision amplifiers and sensors, and the accuracy of detection data is ensured.

Description

Technical Field

[0001] The utility model belongs to the technical field of charging piles, and particularly relates to a on-site detector for DC charging piles. Background Technique

[0002] DC charging piles are an important part of the charging infrastructure for electric vehicles and are widely used in public and private places to provide fast charging services for electric vehicles.

[0003] The detection of DC charging piles includes basic voltage and current detection, as well as simple fault diagnosis functions. At present, various detection instruments are required for the detection of these performances in the existing technology. These detection instruments are of various types and large in size, making it inconvenient to carry them to the site for detecting the already deployed DC charging piles. Content of the Utility Model

[0004] The purpose of the utility model is to provide a on-site detector for DC charging piles, which solves the technical problems of high integration degree, portability, and having diversified communication channels in the DC charging pile system.

[0005] To achieve the above purpose, the utility model adopts the following technical solutions:

[0006] A on-site detector for DC charging piles includes a charging gun interface, an insulation detection module, a main control unit, an analog quantity detection unit, a battery simulator, a power supply module, and a battery pack. The charging gun interface is respectively connected to the analog quantity detection unit and the insulation detection module. The analog quantity detection unit is connected to the battery simulator. The insulation detection module, the analog quantity detection unit, and the battery simulator are all connected to the main control unit. The battery pack is connected to the power supply module, and the power supply module supplies power to the insulation detection module, the main control unit, and the analog quantity detection unit;

[0007] The analog quantity detection unit includes a bus input interface, an access control unit, a voltage acquisition circuit, a current acquisition circuit, an opto-isolation circuit, a voltage division circuit, and a bus output interface. The bus access interface is connected to the charging gun interface. The power cord output by the charging gun is the bus. The bus access interface is also connected to the access control unit. The access control unit is used to control the on-off of the bus power supply circuit between the bus access interface and the bus output interface. The access control unit is connected to the current acquisition circuit, and the current acquisition circuit is connected to the bus output interface. The voltage acquisition circuit is connected to the bus between the access control unit and the current acquisition circuit for acquiring the voltage on the bus. The voltage acquisition circuit is connected to the opto-isolation circuit, and the opto-isolation circuit is connected to the voltage division circuit;

[0008] The main control unit includes a main controller, a 485 communication module, a Bluetooth module, an LCD display screen, a button group, and a LIN communication module. The 485 communication module, the Bluetooth module, the LCD display screen, the button group, and the LIN communication module are all connected to the main controller;

[0009] The access control unit is also connected to an IO port of the main control unit; the current acquisition current is connected to an AD interface of the main control unit, and the voltage dividing circuit is connected to another AD interface of the main control unit.

[0010] Preferably, the bus input interface is interface J1, and the bus output interface is interface J3; the access control unit includes a relay J2, a triode A1, a resistor R1, a resistor R2, and a freewheeling diode D1. The two common terminals of the relay J2 are respectively connected to the 1st and 2nd pins of the interface J1, and the two normally open terminals respectively output the DC+ power supply and the DC- power supply. The DC+ power supply and the DC- power supply constitute the bus. One end of the coil of the relay J2 is connected to the VCC power supply, and the other end is connected to the collector of the triode A1. The emitter of the triode A1 is connected to the ground wire, and the base is connected to an IO port of the main controller through the resistor R1. The resistor R2 is connected in parallel between the base and the emitter of the triode A1. A freewheeling diode D1 is also connected in parallel across the two ends of the coil of the relay J2;

[0011] The current acquisition circuit is composed of a current acquisition chip IC1 and its peripheral circuit. The 4th pin of the current acquisition chip IC1 is connected to the DC+ power supply, the 5th pin is connected to the 1st pin of the interface J3, the 2nd pin of the interface J3 is connected to the DC- power supply, and the 3rd pin of the current acquisition chip IC1 is connected to an AD interface of the main controller through a resistor R5.

[0012] Preferably, the model of the current acquisition chip IC1 is ACS758 current sensor, and the relay J2 is a double-pole relay.

[0013] Preferably, the voltage acquisition circuit includes a resistor R3 and a resistor R4, and the opto-isolation circuit includes an amplifier IC3, an opto-coupler IC3, an amplifier IC4, a resistor R6, a resistor R7, a capacitor C3, and a resistor R8. The resistor R3 and the resistor R4 constitute a voltage sampling circuit for collecting the voltage signal on the DC+ power supply. The positive input terminal of the amplifier IC3 is connected to the voltage sampling circuit, the negative input terminal is connected to the ground wire through the resistor R6, and the output terminal is connected to the LEDA terminal of the opto-coupler IC3 through the resistor R7. One end of the capacitor C3 is connected to the output terminal of the amplifier IC3, and the other end is connected to the ground wire. The LEDK terminal and the PDA1 terminal of the opto-coupler IC3 are connected to the ground wire, the PDK1 terminal and the PDK2 are connected to the VCC power supply, and the PDA2 terminal is connected to the positive input terminal of the amplifier IC4;

[0014] The positive input terminal of the amplifier IC4 is also connected to the ground wire through the resistor R8, and the negative input terminal and the output terminal of the amplifier IC4 are connected together;

[0015] The voltage dividing circuit includes resistor R9 and resistor R10. One end of resistor R9 is connected to the output end of amplifier IC4, and the other end is respectively connected to one end of resistor R10 and an AD interface of the main controller. The other end of resistor R10 is connected to the ground wire.

[0016] Preferably, the models of amplifier IC3 and amplifier IC4 are both TLE2022, and the model of optocoupler IC2 is TIL300.

[0017] Preferably, the model of the insulation detection module is KCDCG-U insulation resistance detection module, and the insulation detection module communicates with the 485 communication module through the 485 bus;

[0018] The model of the battery simulator is Chroma 62000D bidirectional programmable DC power supply, and the battery simulator communicates with the LIN communication module through the LIN bus.

[0019] Preferably, the model of the main controller is STM32F429ZI, the model of the 485 communication module is MAX485, the model of the Bluetooth module is RN4871, and the model of the LIN communication module is TJA1020.

[0020] Preferably, the power supply module includes a battery management chip BQ76940 and its peripheral circuit, a DC-DC 24V to 12V module, a 5V module, and a 3.3V module. The battery pack is a 24V lithium battery pack. The battery management chip BQ76940 is connected to the battery pack, and the battery management chip BQ76940 is also connected to the DC-DC 24V to 12V module. The DC-DC 24V to 12V module is connected to the 5V module, and the 5V module is connected to the 3.3V module;

[0021] The model of the DC-DC 24V to 12V module is LDD12-24S12 power supply module, the model of the 5V module is LM2675, and the model of the 3.3V module is AMS1117.

[0022] A DC charging pile on-site detector described in the present utility model solves the technical problems of high integration, portability, and having diverse communication channels in the DC charging pile system. The present utility model integrates various detection functions, including voltage, current, insulation, etc., and can comprehensively monitor the status of the DC charging pile. It is equipped with a 485 communication module, a Bluetooth module, and a LIN communication module, ensuring convenient communication with external devices and systems, enhancing the interoperability and compatibility of the system. The independent insulation detection module and the optocoupler isolation circuit improve the safety of the system and ensure reliable operation in a high-voltage environment. The voltage acquisition circuit and the current acquisition circuit adopt high-precision amplifiers and sensors, ensuring the accuracy of the detection data. Description of the Drawings

[0023] Figure 1 is the block diagram of the main schematic diagram of the present utility model;

[0024] Figure 2 is the block diagram of the schematic diagram of the analog quantity detection unit of the present utility model;

[0025] Figure 3 is the block diagram of the schematic diagram of the main control unit of the present utility model;

[0026] Figure 4 is the circuit diagram of the analog quantity detection unit of the present utility model. Detailed Embodiment

[0027] Composed of Figures 1-4 A on-site detector for a DC charging pile shown in the figure, including a charging gun interface, an insulation detection module, a main control unit, an analog quantity detection unit, a battery simulator, a power supply module and a battery pack. The charging gun interface is respectively connected to the analog quantity detection unit and the insulation detection module. The analog quantity detection unit is connected to the battery simulator. The insulation detection module, the analog quantity detection unit and the battery simulator are all connected to the main control unit. The battery pack is connected to the power supply module. The power supply module supplies power to the insulation detection module, the main control unit and the analog quantity detection unit;

[0028] The analog quantity detection unit includes a bus input interface, an access control unit, a voltage acquisition circuit, a current acquisition circuit, an opto-isolation circuit, a voltage division circuit and a bus output interface. The bus access interface is connected to the charging gun interface. The power line output by the charging gun is the bus. The bus access interface is also connected to the access control unit. The access control unit is used to control the on / off of the bus power supply loop between the bus access interface and the bus output interface. The access control unit is connected to the current acquisition circuit. The current acquisition circuit is connected to the bus output interface. The voltage acquisition circuit is connected to the bus between the access control unit and the current acquisition circuit for acquiring the voltage on the bus. The voltage acquisition circuit is connected to the opto-isolation circuit. The opto-isolation circuit is connected to the voltage division circuit;

[0029] The bus input interface is interface J1, and the bus output interface is interface J3; The access control unit includes relay J2, triode A1, resistor R1, resistor R2, and freewheeling diode D1. The two common terminals of relay J2 are respectively connected to pin 1 and pin 2 of interface J1, and the two normally open terminals respectively output DC+ power supply and DC- power supply. The DC+ power supply and DC- power supply constitute the bus. One end of the coil of relay J2 is connected to the VCC power supply, and the other end is connected to the collector of triode A1. The emitter of triode A1 is connected to the ground wire, and the base is connected to an IO port of the main controller through resistor R1. Resistor R2 is connected in parallel between the base and emitter of triode A1. A freewheeling diode D1 is also connected in parallel across the two ends of the coil of relay J2;

[0030] Relay J2 is controlled by triode A1, and triode A1 is controlled by an IO port of the main controller. When the charging gun is connected, interface J1 is powered on. After the main controller controls relay J2 to close, the bus voltage is applied to the analog quantity detection unit, thus avoiding the influence of events such as poor contact on the finally collected signal.

[0031] In this embodiment, the access control unit is a protection circuit, which further improves the stability of the system. The design of the relay can effectively control the current path and protect the detection device from overload and short circuit damage.

[0032] The current acquisition circuit is composed of current acquisition chip IC1 and its peripheral circuit. Pin 4 of current acquisition chip IC1 is connected to the DC+ power supply, pin 5 is connected to pin 1 of interface J3, pin 2 of interface J3 is connected to the DC- power supply, and pin 3 of current acquisition chip IC1 is connected to an AD interface of the main controller through a resistor R5.

[0033] When the bus voltage is connected to current acquisition chip IC1 through relay J2, current acquisition chip IC1 acquires the current on the bus and outputs it to the battery simulator through the bus output interface. Current acquisition chip IC1 is connected in series on the bus and will not affect the charging of the bus to the battery simulator.

[0034] The voltage acquisition circuit includes resistor R3 and resistor R4. The opto-isolation circuit includes amplifier IC3, opto-coupler IC3, amplifier IC4, resistor R6, resistor R7, capacitor C3, and resistor R8. Resistor R3 and resistor R4 constitute the voltage sampling circuit for acquiring the voltage signal on the DC+ power supply. The positive input terminal of amplifier IC3 is connected to the voltage sampling circuit, the negative input terminal is connected to the ground wire through resistor R6, and the output terminal is connected to the LEDA terminal of opto-coupler IC3 through resistor R7. One end of capacitor C3 is connected to the output terminal of amplifier IC3, and the other end is connected to the ground wire. The LEDK terminal and PDA1 terminal of opto-coupler IC3 are connected to the ground wire, the PDK1 terminal and PDK2 are connected to the VCC power supply, and the PDA2 terminal is connected to the positive input terminal of amplifier IC4;

[0035] The positive input terminal of amplifier IC4 is also connected to the ground wire through resistor R8, and the negative input terminal and the output terminal of amplifier IC4 are connected together;

[0036] The voltage dividing circuit includes resistor R9 and resistor R10. One end of resistor R9 is connected to the output terminal of amplifier IC4, and the other end is respectively connected to one end of resistor R10 and an AD interface of the main controller. The other end of resistor R10 is connected to the ground wire.

[0037] The voltage acquisition circuit first acquires the voltage on the bus through voltage dividing resistors R3 and R4, then undergoes isolation sampling through the linear optocoupler isolation circuit composed of amplifier IC3, optocoupler IC2, and amplifier IC4, and then is divided by another set of voltage dividing resistors (resistor R9 and resistor R10), and finally is input to the AD interface of the main controller for AD processing.

[0038] The voltage acquisition circuit and current acquisition circuit of the present utility model adopt high-precision amplifiers and sensors, such as TLE2022 and ACS758, which ensure the accuracy of the detection data.

[0039] The main control unit includes a main controller, a 485 communication module, a Bluetooth module, an LCD display screen, a key group, and a LIN communication module. The 485 communication module, the Bluetooth module, the LCD display screen, the key group, and the LIN communication module are all connected to the main controller;

[0040] In this embodiment, the model of the main controller is STM32F429ZI, the model of the 485 communication module is MAX485, the model of the Bluetooth module is RN4871, the model of the LIN communication module is TJA1020. The LCD display screen can adopt the ILI9341 type LCD display screen. The ILI9341 type LCD display screen is connected to the main controller using a parallel RGB interface or an SPI interface. MAX485 communicates with STM32F429ZI through a UART interface, TJA1020 communicates with STM32F429ZI through a UART interface, and RN4871 communicates with STM32F429ZI through a UART or SPI interface.

[0041] The main controller uses STM32F429ZI, which has powerful processing capabilities and rich peripheral interfaces. The high-speed processing capabilities and various interfaces of STM32F429ZI enable the system to quickly respond to and process a large amount of data, improving the overall performance of the system.

[0042] The access control unit is also connected to an IO port of the main control unit; the current acquisition circuit is connected to an AD interface of the main control unit, and the voltage dividing circuit is connected to another AD interface of the main control unit.

[0043] The model of the current acquisition chip IC1 is the ACS758 current sensor, and the relay J2 is a double-pole relay.

[0044] The models of the amplifier IC3 and the amplifier IC4 are both TLE2022, and the model of the optocoupler IC2 is TIL300.

[0045] The model of the insulation detection module is the KCDCG-U insulation resistance detection module, and the insulation detection module communicates with the 485 communication module through the 485 bus;

[0046] In the present utility model, the insulation detection module adopts an independent KCDCG-U insulation resistance detection module, which can monitor the insulation state of the charging pile in real time, discover potential safety hazards in time, and increase safety.

[0047] The model of the battery simulator is the Chroma 62000D bidirectional programmable DC power supply, and the battery simulator communicates with the LIN communication module through the LIN bus.

[0048] In this embodiment, the Chroma 62000D battery simulator is adopted, which can simulate complex battery charging and discharging processes and adapt to different test requirements. The high precision and programmability of this simulator can simulate various charging states, improving the flexibility and precision of detection.

[0049] The power supply module includes a battery management chip BQ76940 and its peripheral circuits, a DC-DC 24V to 12V module, a 5V module, and a 3.3V module. The battery pack is a 24V lithium battery pack. The battery management chip BQ76940 is connected to the battery pack, and the battery management chip BQ76940 is also connected to the DC-DC 24V to 12V module. The DC-DC 24V to 12V module is connected to the 5V module, and the 5V module is connected to the 3.3V module;

[0050] The model of the DC-DC 24V to 12V module is the LDD12-24S12 power supply module, the model of the 5V module is LM2675, and the model of the 3.3V module is AMS1117.

[0051] The power supply module in this embodiment is comprehensively designed, including DC-DC conversion, 5V and 3.3V voltage stabilization modules, ensuring stable power supply for each module. The efficient design of the power management module ensures the stability and reliability of the system during long-term operation

[0052] In this embodiment, the 3.3V module is used to supply power to the Bluetooth chip RN4871, the LIN chip TJA1020, and the power supply requirements of some ARMs, and the 5V module is used to supply power to the RS-485 chip MAX485 and the LCD screen ILI9341.

[0053] This utility model is equipped with a 24V lithium battery pack, having high endurance capacity and capable of meeting various on-site requirements.

[0054] A kind of on-site detector for DC charging piles of this utility model solves the technical problems of high integration degree, portability and having diversified communication channels of the DC charging pile system. A variety of detection functions are integrated in this utility model, including voltage, current, insulation, etc., capable of comprehensively monitoring the state of the DC charging pile, equipped with a 485 communication module, a Bluetooth module and a LIN communication module, ensuring convenient communication with external devices and systems, enhancing the interoperability and compatibility of the system. The independent insulation detection module and the use of optocoupler isolation circuit improve the safety of the system, ensuring reliable operation in a high-voltage environment. The voltage acquisition circuit and the current acquisition circuit adopt high-precision amplifiers and sensors, guaranteeing the accuracy of the detection data.

Claims

1. A on-site detector for DC charging piles, characterized in that: It includes a charging gun interface, an insulation detection module, a main control unit, an analog quantity detection unit, a battery simulator, a power supply module and a battery pack. The charging gun interface is respectively connected to the analog quantity detection unit and the insulation detection module. The analog quantity detection unit is connected to the battery simulator. The insulation detection module, the analog quantity detection unit and the battery simulator are all connected to the main control unit. The battery pack is connected to the power supply module, and the power supply module supplies power to the insulation detection module, the main control unit and the analog quantity detection unit; The analog quantity detection unit includes a bus input interface, an access control unit, a voltage acquisition circuit, a current acquisition circuit, an opto-isolation circuit, a voltage dividing circuit and a bus output interface. The bus access interface is connected to the charging gun interface, and the power line output by the charging gun is the bus. The bus access interface is also connected to the access control unit. The access control unit is used to control the on-off of the bus power supply loop between the bus access interface and the bus output interface. The access control unit is connected to the current acquisition circuit, and the current acquisition circuit is connected to the bus output interface. The voltage acquisition circuit is connected to the bus between the access control unit and the current acquisition circuit for acquiring the voltage on the bus. The voltage acquisition circuit is connected to the opto-isolation circuit, and the opto-isolation circuit is connected to the voltage dividing circuit; The main control unit includes a main controller, a 485 communication module, a Bluetooth module, an LCD display screen, a key group and a LIN communication module. The 485 communication module, the Bluetooth module, the LCD display screen, the key group and the LIN communication module are all connected to the main controller; The access control unit is also connected to an IO port of the main control unit; the current acquisition current is connected to an AD interface of the main control unit, and the voltage dividing circuit is connected to another AD interface of the main control unit.

2. The on-site detector for DC charging piles according to claim 1, wherein: The bus input interface is interface J1, and the bus output interface is interface J3; the access control unit includes a relay J2, a triode A1, a resistor R1, a resistor R2 and a freewheeling diode D1. The two common terminals of the relay J2 are respectively connected to pin 1 and pin 2 of the interface J1, and the two normally open terminals respectively output DC+ power and DC- power. The DC+ power and DC- power constitute the bus. One end of the coil of the relay J2 is connected to the VCC power supply, and the other end is connected to the collector of the triode A1. The emitter of the triode A1 is connected to the ground wire, and the base is connected to an IO port of the main controller through the resistor R1. The resistor R2 is connected in parallel between the base and the emitter of the triode A1. A freewheeling diode D1 is also connected in parallel across the two ends of the coil of the relay J2; The current acquisition circuit is composed of a current acquisition chip IC1 and its peripheral circuits. Pin 4 of the current acquisition chip IC1 is connected to the DC+ power supply, pin 5 is connected to pin 1 of the interface J3, and pin 2 of the interface J3 is connected to the DC- power supply. Pin 3 of the current acquisition chip IC1 is connected to an AD interface of the main controller through a resistor R5.

3. The on-site detector for a DC charging pile according to claim 2, characterized in that: The model of the current acquisition chip IC1 is ACS758 current sensor, and the relay J2 is a double-pole relay.

4. The on-site detector for a DC charging pile according to claim 2, characterized in that: The voltage acquisition circuit includes resistor R3 and resistor R4. The opto-isolation circuit includes amplifier IC3, opto-coupler IC3, amplifier IC4, resistor R6, resistor R7, capacitor C3 and resistor R8. Resistor R3 and resistor R4 form a voltage sampling circuit for acquiring the voltage signal on the DC+ power supply. The positive input terminal of amplifier IC3 is connected to the voltage sampling circuit, the negative input terminal is connected to the ground wire through resistor R6, and the output terminal is connected to the LEDA terminal of opto-coupler IC3 through resistor R7. One end of capacitor C3 is connected to the output terminal of amplifier IC3 and the other end is connected to the ground wire. The LEDK terminal and PDA1 terminal of opto-coupler IC3 are connected to the ground wire, the PDK1 terminal and PDK2 are connected to the VCC power supply, and the PDA2 terminal is connected to the positive input terminal of amplifier IC4; The positive input terminal of amplifier IC4 is also connected to the ground wire through resistor R8, and the negative input terminal and the output terminal of amplifier IC4 are connected together; The voltage division circuit includes resistor R9 and resistor R10. One end of resistor R9 is connected to the output terminal of amplifier IC4, and the other end is respectively connected to one end of resistor R10 and an AD interface of the main controller. The other end of resistor R10 is connected to the ground wire.

5. The on-site detector for a DC charging pile according to claim 4, wherein: The models of amplifier IC3 and amplifier IC4 are both TLE2022, and the model of opto-coupler IC2 is TIL300.

6. The on-site detector for a DC charging pile according to claim 1, characterized in that: The model of the insulation detection module is the KCDCG-U insulation resistance detection module, and the insulation detection module communicates with the 485 communication module through the 485 bus; The model of the battery simulator is the Chroma 62000D bidirectional programmable DC power supply, and the battery simulator communicates with the LIN communication module through the LIN bus.

7. The on-site detector for a DC charging pile according to claim 1, wherein: The model of the main controller is STM32F429ZI, the model of the 485 communication module is MAX485, the model of the Bluetooth module is RN4871, and the model of the LIN communication module is TJA1020.

8. The on-site detector for a DC charging pile according to claim 1, characterized in that: The power supply module includes the battery management chip BQ76940 and its peripheral circuit, the DC-DC 24V to 12V module, the 5V module and the 3.3V module. The battery pack is a 24V lithium battery pack. The battery management chip BQ76940 is connected to the battery pack, and the battery management chip BQ76940 is also connected to the DC-DC 24V to 12V module. The DC-DC 24V to 12V module is connected to the 5V module, and the 5V module is connected to the 3.3V module; The model of the DC-DC 24V to 12V module is the LDD12-24S12 power supply module, the model of the 5V module is LM2675, and the model of the 3.3V module is AMS1117.

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