阅读说明：本技术 一种具有铅酸充电功能的国标直流充电桩系统 (National standard direct current fills electric pile system with lead acid charging function ) 是由 王方达 黎庭 黄剑文 佘武 薛泽林 于 2021-11-11 设计创作，主要内容包括：本发明公开一种具有铅酸充电功能的国标直流充电桩系统,包括充电桩装置和充电系统,充电桩装置包括直流充电枪和铅酸充电接口,充电系统包括系统控制单元MCU、计费控制单元TCU、检测单元、功率单元和操作单元,系统控制单元MCU与计费控制单元TCU之间通过CAN通讯进行数据交互,再通过无线通信模组连接云平台进行操作,系统控制单元MCU与检测单元、功率单元和操作单元通过串口通讯方式进行交互；充电系统的供电电路包括主回路和辅电回路,主回路连接主回路开关和主回路接触器,主回路接触器连接有A枪回路电路和B枪回路电路,辅电回路输出端电连接有辅助电源断路器、主控板电子锁电源、A枪辅助电源、B枪辅助电源和器件辅助电源。(The invention discloses a national standard direct current charging pile system with a lead-acid charging function, which comprises a charging pile device and a charging system, wherein the charging pile device comprises a direct current charging gun and a lead-acid charging interface; the power supply circuit of the charging system comprises a main circuit and an auxiliary circuit, the main circuit is connected with a main circuit switch and a main circuit contactor, the main circuit contactor is connected with an A gun circuit and a B gun circuit, and the output end of the auxiliary circuit is electrically connected with an auxiliary power circuit breaker, a main control panel electronic lock power supply, an A gun auxiliary power supply, a B gun auxiliary power supply and a device auxiliary power supply.)

1. The utility model provides a national standard direct current fills electric pile system with lead acid charging function, fills the electric pile device and locates the charging system who fills in the electric pile device including filling, its characterized in that: the charging pile device comprises at least one direct-current charging gun and at least one lead-acid charging interface, the charging system comprises a system control unit MCU, a charging control unit TCU connected with the system control unit MCU, a detection unit, a power unit and an operation unit, the system control unit MCU and the charging control unit TCU are communicated through a CAN (controller area network) for data interaction, and then are connected with a cloud platform through a wireless communication module for operation, and the system control unit MCU is interacted with the detection unit, the power unit and the operation unit through a serial port communication mode;

charging system's power supply circuit includes major loop and auxiliary circuit, major loop switch and major loop contactor are connected to the major loop output, be connected with lightning protection switch and lightning protection device between major loop and the major loop switch, major loop contactor output is connected with A rifle circuit and B rifle circuit, auxiliary circuit output electricity is connected with auxiliary power circuit breaker, main control board electronic lock power, A rifle auxiliary power, B rifle auxiliary power and device auxiliary power.

2. The national standard direct current charging pile system with the lead-acid charging function according to claim 1, characterized in that: the detection unit comprises an overvoltage detection module, an undervoltage detection module, an overcurrent detection module, a metering fault detection module, a relay adhesion detection module, a BMS fault detection module, an emergency stop detection module, an entrance guard detection module, a power fault detection module, an insulation detection module, a TCU fault detection module and a CC1 control guide detection module, the power unit comprises an AC-DC module, a direct current digital electric meter, an auxiliary electric loop, an IC card reader and a temperature sensor, and the operation unit comprises a touch screen, an indicator light and a loudspeaker.

3. The national standard direct current charging pile system with the lead-acid charging function according to claim 2, characterized in that: the insulation detection module is an acquisition chip integrated on a system control unit MCU, the insulation detection module calculates the insulation resistance value between the main loop and the ground by acquiring the voltage value on the main loop, judges whether the resistance value meets a standard value or not to judge the current insulation performance of the charging pile equipment, and the voltage sampling of the insulation detection module is used as the charging voltage sampling of the lead-acid battery to control the charging current of the lead-acid battery.

4. The national standard direct current charging pile system with the lead-acid charging function according to claim 2, characterized in that: the AC-DC module comprises a plurality of groups or a plurality of groups, the voltage range of each AC-DC module is 0VDC-800VDC, the charging rated power is 20kW, and the AC-DC module outputs full power in the low-voltage charging process.

5. The national standard direct current charging pile system with the lead-acid charging function according to claim 1, characterized in that: the wireless communication module comprises a LAN module, a GPRS module and a WIFI module.

6. The national standard direct current charging pile system with the lead-acid charging function according to claim 1, characterized in that: fill electric pile device and include four guns that charge, two guns that charge for national standard direct current, two in addition are the interface that charges for lead acid battery, during charging, divide into two kinds of charge mode, one kind is: one side charges and lead-acid batteries system to a national standard new energy automobile simultaneously, and another kind is: one side charges a national standard new energy automobile, and the other side charges a lead-acid battery system.

7. The national standard direct current charging pile system with the lead-acid charging function according to claim 1, characterized in that: a rifle return circuit includes A rifle AC-DC module and rather than the A rifle fuse, A rifle bleeder circuit, A rifle electric energy detection circuitry, survey sampling circuit in the A rifle, A rifle high voltage direct current relay, A rifle outward survey sampling circuit, national standard A rifle and lead-acid A rifle that connect gradually, B rifle return circuit includes B rifle AC-DC module and rather than survey sampling circuit, B rifle bleeder circuit, B rifle electric energy detection circuitry, B rifle in the B rifle, B rifle high voltage direct current relay, B rifle outward survey sampling circuit, national standard B rifle and lead-acid B rifle that connect gradually, be equipped with the switching relay between A rifle return circuit and the B rifle return circuit, A rifle switching and A rifle bleeder circuit are connected to relay one end, and the other end is connected between B rifle fuse and B rifle bleeder circuit.

8. The national standard direct current charging pile system with the lead-acid charging function according to claim 1, characterized in that: the main circuit is three-phase 380V alternating current input, and the auxiliary circuit is auxiliary single-phase 220V alternating current input.

Technical Field

The invention relates to the technical field of direct current charging piles, in particular to a national standard direct current charging pile system with a lead-acid charging function.

Background

Recently, the development of electric vehicle charging facilities is actively promoted in China, rapid charging equipment mainly uses a national standard direct current charging pile as a main part, but the national standard direct current charging pile in the market is a lithium battery charging system following a national standard protocol, but the number of electric vehicles or equipment (including low-speed electric vehicles such as forklifts, special operation electric vehicles, tourist carriages and electric lift trucks) using lead-acid batteries in the engineering application field is increased, and at present, the electric vehicles of the lead-acid batteries are generally still vehicles with charging equipment corresponding to specific matching, so that the user cost and the consumption of various social resources are increased, and therefore, the national standard direct current charging pile system with the lead-acid charging function needs to be designed.

The basic working principle of the national standard direct current charging pile in the prior art is that three-phase 380V alternating current enters a three-phase four-wire system ammeter after passing through an EMC (electro magnetic compatibility) and other lightning protection and filtering modules, and the three-phase four-wire system ammeter monitors the actual charging electric quantity of the whole charger during working. According to the actual charging current and the charging voltage, the chargers are often used in parallel, so that the chargers are required to have a current-sharing output function, and the output of the chargers is directly charged to the power batteries through the charging guns. When the direct current charging pile works, the auxiliary power supply supplies power to control systems such as the main control unit, the display module, the protection control unit, the signal acquisition unit and the card swiping module. In addition, in the charging process of the power battery, the auxiliary power supply supplies power to the BMS system, and the BMS system monitors the state of the power battery in real time.

The state standard direct current of prior art fills electric pile and can't charge for electric motor car or the equipment that uses lead-acid batteries, and application range is more restricted, and the electric motor car or the equipment that use lead-acid batteries charge more difficultly, and it is extremely inconvenient to charge.

The state standard direct current of prior art fills electric pile can't guarantee full power full load output under the operating mode that lower voltage output charges, and efficiency can't be ensured, nevertheless uses lead-acid batteries's electric motor car or equipment to generally belong to lower voltage and charge.

Therefore, there is a need for a dc charging post with a lead-acid charging function to solve the above problems.

Disclosure of Invention

The invention mainly aims to provide a national standard direct current charging pile system with a lead-acid charging function, and aims to solve the problems that lead-acid batteries with different specifications need different chargers in the prior art and the technical problem that the national standard direct current charging pile in the prior art cannot charge the lead-acid battery system.

In order to achieve the purpose, the invention provides a national standard direct current charging pile system with a lead-acid charging function, which comprises a charging pile device and a charging system arranged in the charging pile device, wherein the charging pile device comprises at least one direct current charging gun and at least one lead-acid charging interface, the charging system comprises a system control unit MCU, a charging control unit TCU connected with the system control unit MCU, a detection unit, a power unit and an operation unit, the system control unit MCU and the charging control unit TCU perform data interaction through CAN communication and are connected with a cloud platform through a wireless communication module for operation, and the system control unit MCU interacts with the detection unit, the power unit and the operation unit through a serial port communication mode;

charging system's power supply circuit includes major loop and auxiliary circuit, major loop switch and major loop contactor are connected to the major loop output, be connected with lightning protection switch and lightning protection device between major loop and the major loop switch, major loop contactor output is connected with A rifle circuit and B rifle circuit, auxiliary circuit output electricity is connected with auxiliary power circuit breaker, main control board electronic lock power, A rifle auxiliary power, B rifle auxiliary power and device auxiliary power.

Preferably, the detection unit comprises an overvoltage detection module, an undervoltage detection module, an overcurrent detection module, a metering fault detection module, a relay adhesion detection module, a BMS fault detection module, an emergency stop detection module, an entrance guard detection module, a power fault detection module, an insulation detection module, a TCU fault detection module and a CC1 control guide detection module, the power unit comprises an AC-DC module, a direct current digital electric meter, an auxiliary electric loop, an IC card reader and a temperature sensor, and the operation unit comprises a touch screen, an indicator light and a loudspeaker.

Preferably, the insulation detection module is an acquisition chip integrated on the system control unit MCU, the insulation detection module calculates an insulation resistance value between the main circuit and the ground by acquiring a voltage value on the main circuit, determines whether the resistance value meets a standard value to determine the current insulation performance of the charging pile device, and the voltage sampling of the insulation detection module is used as the charging voltage sampling of the lead-acid battery to control the charging current of the lead-acid battery.

Preferably, the AC-DC module comprises a plurality of or a plurality of groups, each AC-DC module has the voltage range of 0VDC-800VDC, the charging rated power is 20kW, and the AC-DC module outputs full power in the low-voltage charging process.

Preferably, the wireless communication module comprises a LAN module, a GPRS module and a WIFI module.

Preferably, fill electric pile device and include four guns that charge, two are national standard direct current guns that charge, and another two are the lead acid battery interface that charges, during charging, divide into two kinds of charge mode, one is: one side charges and lead-acid batteries system to a national standard new energy automobile simultaneously, and another kind is: one side charges a national standard new energy automobile, and the other side charges a lead-acid battery system.

Preferably, the rifle a return circuit includes rifle AC-DC module and rather than the A rifle fuse, rifle a bleeder circuit, rifle electric energy detection circuitry, survey sampling circuit in the rifle a, rifle high voltage direct current relay, the rifle a outward survey sampling circuit, national standard A rifle and lead acid A rifle that connect gradually, rifle B return circuit includes rifle AC-DC module and rather than survey sampling circuit, rifle B bleeder circuit, rifle electric energy detection circuitry, the rifle B in the rifle, rifle high voltage direct current relay, rifle B outward survey sampling circuit, national standard B rifle and lead acid B rifle that connect gradually, be equipped with the switching relay between rifle a return circuit and the rifle return circuit of B rifle, relay switching one end is connected between rifle a rifle fuse and the rifle a bleeder circuit, and the other end is connected between rifle fuse of B rifle and rifle bleeder circuit.

Preferably, the main circuit is a three-phase 380V alternating current input, and the auxiliary circuit is an auxiliary single-phase 220V alternating current input.

The national standard direct current charging pile system with the lead-acid charging function provided by the invention has the following advantages:

1. the direct-current charging pile system can charge the electric vehicle or equipment using the lead-acid battery, so that the application range of the charging pile is enlarged, and the charging requirement of the electric vehicle or equipment using the lead-acid battery is facilitated;

2. the direct current charging pile system can simultaneously charge a lithium battery conforming to a national standard protocol and an electric vehicle or equipment using a lead-acid battery;

3. the direct current charging pile system can output full power and full load under the working condition of low-voltage output charging, so that charging use of low-voltage charging vehicles is guaranteed;

4. the input cost and the operation and maintenance cost of an operator are reduced, and the operator can meet the charging requirement of an electric vehicle or equipment using the lead-acid battery without additionally arranging a lead-acid charger.

Drawings

FIG. 1 is a schematic block diagram of an embodiment of a national standard DC charging pile system with lead-acid charging functionality according to the present invention;

FIG. 2 is an electrical schematic diagram of an embodiment of a national standard DC charging pile system with lead-acid charging functionality of the present invention;

fig. 3 is a schematic structural diagram of a charging pile device according to an embodiment of the national standard dc charging pile system with a lead-acid charging function of the present invention;

FIG. 4 is a charging state transition diagram of an embodiment of a national standard DC charging pile system with lead-acid charging function according to the present invention;

fig. 5 is a lead-acid battery charging curve diagram of an embodiment of a national standard dc charging pile system with a lead-acid charging function according to the present invention.

In the figure: 10-charging pile device, 100-charging system, 101-system control unit MCU, 102-charging control unit TCU, 103-detection unit, 104-power unit, 105-operation unit, 106-cloud platform, 1-main loop, 2-main loop switch, 3-main loop contactor, 4-lightning protection switch, 5-lightning protection device, 6-auxiliary circuit, 7-auxiliary power circuit breaker, 8-main control panel electronic lock power supply, 9-A gun auxiliary power supply, 10-B gun auxiliary power supply, 11-device auxiliary power supply, 12-A gun AC-DC module, 13-B gun AC-DC module, 14-A gun fuse, 15-B gun fuse, 16-switching relay, 17-A gun discharge circuit, The device comprises an 18-B gun discharge circuit, a 19-A gun electric energy detection circuit, a 20-B gun electric energy detection circuit, a 21-A gun internal measurement sampling circuit, a 22-A gun external measurement sampling circuit, a 23-B gun internal measurement sampling circuit, a 24-B gun external measurement sampling circuit, a 25-A gun high-voltage direct current relay, a 26-B gun high-voltage direct current relay, a 27-national standard A gun, a 28-national standard B gun, a 29-lead-acid A gun and a 30-lead-acid B gun.

Detailed Description

In the following, the embodiments of the present invention will be described in detail with reference to the drawings in the following, and it is apparent that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The invention provides a national standard direct current charging pile system with a lead-acid charging function, and with reference to fig. 1-5, the system comprises a charging pile device 10 and a charging system 100 arranged in the charging pile device, wherein the charging pile device 10 comprises at least one direct current charging gun and at least one lead-acid charging interface, the charging system 100 comprises a system control unit MCU101, a charging control unit TCU 102 connected with the system control unit MCU101, a detection unit 103, a power unit 104 and an operation unit 105, the system control unit MCU101 and the charging control unit TCU 102 are in data interaction through CAN communication and then are connected with a cloud platform 106 through a wireless communication module for operation, and the system control unit MCU101, the detection unit 103, the power unit 104 and the operation unit 105 are in interaction through a serial port communication mode.

The power supply circuit of the charging system comprises a main circuit 1 and an auxiliary circuit 6, the output end of the main circuit 1 is connected with a main circuit switch 2 and a main circuit contactor 3, a lightning protection switch 4 and a lightning protector 5 are connected between the main circuit 1 and the main circuit switch 2, the output end of the main circuit contactor 3 is connected with an A gun circuit and a B gun circuit, and the output end of the auxiliary circuit 6 is electrically connected with an auxiliary power circuit breaker 7, a main control panel electronic lock power supply 8, an A gun auxiliary power supply 9, a B gun auxiliary power supply 10 and a device auxiliary power supply 11.

The invention relates to a direct-current charging pile system with a lead-acid charging function, which comprises a charging pile device 10 and a charging system 100, wherein the charging pile device 10 comprises at least one direct-current charging gun and at least one lead-acid charging interface, the charging system 100 comprises a system control unit MCU101, a charging control unit TCU 102, a detection unit 103, a power unit 104 and an operation unit 105, and the system control unit MCU101 is communicated with all parts in a common serial port communication mode, so that the purposes of monitoring the system, measuring related charging data, controlling a charging process and ensuring safe charging are achieved; the system control unit MCU101 and the charging control unit TCU 102 perform data interaction through CAN communication, charging bill data CAN be generated according to the interaction data, and then the charging bill data is connected with the cloud platform 106 through the wireless communication module to perform operations such as remote measurement, remote control and remote signaling.

The power supply circuit of the charging system comprises a main circuit 1 and an auxiliary circuit 6, when the charging system is normal, a main circuit switch 2 is closed, the auxiliary circuit 6 gets power from the rear end, an auxiliary power circuit breaker 7 is closed, a main control panel electronic lock power supply 8 and other devices get power, a system control unit MCU101 sends out a closing driving signal to control a main circuit contactor 3 to be closed, so that an A gun circuit and a B gun circuit obtain alternating current input to work and perform data interaction with the main control panel, and the whole system is powered on to complete the operation.

The charging system has two start-stop charging modes:

1. scanning a charging instruction below the two-dimensional code displayed by the touch screen through WeChat;

2. the appointed charging card is identified through the IC card reader in the appointed card swiping area to start charging, and data such as charging voltage, current and electric quantity in the charging process can be checked through the touch screen after the charging is started.

The charging system has a metering and charging function, reads the values of voltage value, current value and electric energy value in the current charging process in real time through a direct current digital ammeter of the power unit to count charging data, and uploads the charging data to the charging control unit TCU 102 to generate a charging bill in combination with the charge rate.

In a preferred embodiment, referring to fig. 1, the detecting unit 103 of the dc charging pile system includes an overvoltage detecting module, an undervoltage detecting module, an overcurrent detecting module, a metering failure detecting module, a relay adhesion detecting module, a BMS failure detecting module, an emergency stop detecting module, an entrance guard detecting module, a power failure detecting module, an insulation detecting module, a TCU failure detecting module, and a CC1 control guidance detecting module. The system has multiple protection functions of overvoltage detection, undervoltage detection, overcurrent detection, metering fault detection, relay adhesion detection, BMS fault detection, emergency stop detection, entrance guard detection, power fault detection, insulation detection, TCU fault detection, CC1 control guide detection and the like.

Power unit 104 includes an AC-DC module, a direct current digital meter, an auxiliary electrical loop, an IC card reader, and a temperature sensor. The operation unit 105 includes a touch panel, an indicator lamp, and a speaker.

The charging system can perform parameter configuration by operating the touch screen,

firstly, power module parameter configuration: configuring parameters such as the number of power modules, output voltage, output current, overvoltage value, undervoltage value, overcurrent value, module manufacturers and the like;

secondly, system parameter configuration: configuring parameters such as system output capacity, system client parameters, system fault shielding and the like;

thirdly, network parameter configuration: and configuring parameters such as whether to connect a network, a networking mode, an IP address, a port number and the like.

In order to prompt a user of a charging step, a current charging state and an equipment running state, the charging system prompts charging information, a charging process, fault information, a charging operation step and the like through the touch screen, the indicating lamp prompts the current state of the system to comprise a standby state, a charging state, a fault state and the like, and the loudspeaker can prompt the current state in a voice mode.

In a preferred embodiment, referring to fig. 1, the insulation detection module is an acquisition chip integrated on the system control unit MCU101, the insulation detection module calculates an insulation resistance value between the main circuit and the ground by acquiring a voltage value on the main circuit, determines whether the resistance value meets a standard value to determine the current insulation performance of the charging pile device, and samples the voltage of the insulation detection module as a charging voltage of the lead-acid battery to control the charging current of the lead-acid battery.

In a preferred embodiment, referring to FIG. 2, the AC-DC modules include multiple or multiple sets, each AC-DC module having a voltage range of 0VDC to 800VDC and a charging power rating of 20kW, and the AC-DC modules output full power during low voltage charging. The output current and voltage of the conventional Buck converter are usually limited to a certain extent, and the requirements of low-voltage and high-current equipment cannot be met. The system adopts the power module to design a low-voltage large-current synchronous rectification Buck converter, calculates relevant parameters of an inductor, a capacitor, a switch and a rectifier tube through theoretical analysis, selects appropriate components and parts by considering actual conditions, reduces the power loss of the rectifier tube to a great extent by adopting a synchronous rectification technology, improves the working efficiency, and can ensure that the system outputs full power in a lower-voltage charging process by adopting the AC-DC module.

In a preferred embodiment, referring to fig. 1, the wireless communication module includes a LAN module, a GPRS module, and a WIFI module, and also includes other communication modes, and the wireless communication module interacts with the cloud platform 106 for remote control.

In a preferred embodiment, referring to fig. 3, the charging pile device 10 includes four charging guns, two of which are national standard dc charging guns 11 and two of which are charging interfaces 12 for lead-acid batteries, and during charging, two charging modes are divided, one of which is: one side charges and lead-acid batteries system to a national standard new energy automobile simultaneously, and another kind is: one side charges a national standard new energy automobile, and the other side charges a lead-acid battery system.

In a preferred embodiment, referring to fig. 2, the a-gun circuit includes an a-gun AC-DC module 12 and an a-gun fuse 14, an a-gun bleeder circuit 17, an a-gun power detection circuit 19, an a-gun in-gun sampling circuit 21, an a-gun high voltage DC relay 25, an a-gun out-of-gun sampling circuit 22, a national standard a-gun 27, and a lead-acid a-gun 29 connected in series thereto.

The B gun loop circuit comprises a B gun AC-DC module 13, a B gun fuse 15, a B gun discharge circuit 18, a B gun electric energy detection circuit 20, a B gun internal measurement sampling circuit 23, a B gun high-voltage direct current relay 26, a B gun external measurement sampling circuit 24, a national standard B gun 28 and a lead-acid B gun 30 which are sequentially connected with the B gun AC-DC module, a switching relay 16 is arranged between the A gun loop circuit and the B gun loop circuit, one end of the switching relay 16 is connected between the A gun fuse 14 and the A gun discharge circuit 17, and the other end of the switching relay is connected between the B gun fuse 15 and the B gun discharge circuit 18.

In a preferred embodiment, referring to fig. 2, the primary circuit 1 is a three-phase 380V ac input and the secondary circuit 6 is an auxiliary single-phase 220V ac input.

The national standard direct current charging pile system with the lead-acid charging function comprises three working conditions, wherein one working condition is that a national standard direct current charging gun is used for charging a national standard new energy automobile; secondly, charging a lead-acid system battery by using a lead-acid charging interface; and thirdly, charging the national standard gun A and the lead-acid gun B simultaneously.

When using the national standard direct current rifle that charges to charge for the national standard new energy automobile, insert the car socket that charges with standard national standard A rifle 27 and national standard B rifle 28 earlier, whether can judge the rifle that charges and connect according to CC1 control guide detection, connect normal touch-sensitive screen display and connect, select the payment mode according to the touch-sensitive screen suggestion, start charging behind the selection mode, mechanical lock and electronic lock linkage, locking rifle that charges, then the self-checking process, this process includes three stage: the method comprises a low-voltage auxiliary power-on stage, a charging handshake stage and a charging parameter configuration stage. In the process, the charging pile system realizes insulation detection, and the discharge resistors in the gun A discharge circuit 17 and the gun B discharge circuit 18 are started to discharge the high voltage during insulation detection to below 60V. In the process, the auxiliary power supply on the charging pile supplies power to the national standard new energy automobile terminal BMS through the A gun auxiliary power supply 9 or the B gun auxiliary power supply 10, the national standard new energy automobile terminal BMS starts to work, data interaction, handshaking and charging related parameters are carried out between the charging pile and the national standard new energy automobile terminal BMS, and the national standard new energy automobile terminal BMS informs of the related information of the battery of the charging pile.

After all the things are ready, the system control unit MCU101 issues an instruction to the A gun AC-DC module 12 and the B gun AC-DC module 13, and the A gun AC-DC module 12 and the B gun AC-DC module 13 start to work according to the output voltage and the output current required by the instruction, and continuously charge the power battery of the electric automobile. In the charging process, the national standard new energy automobile terminal BMS control system and the system control unit MCU101 communicate in real time, and the output voltage and the output current of the A gun AC-DC module 12 and the B gun AC-DC module 13 are adjusted in real time according to the requirements reported by the national standard new energy automobile terminal BMS control system.

The charging end is generally divided into three types: the charging is stopped artificially, the charging pile judges that the charging is stopped, and the national standard new energy automobile terminal BMS control system judges that the charging is stopped. After the charging condition is triggered and ended in the charging process, the system control unit MCU101 issues a stop working instruction to the gun A AC-DC module 12 and the gun B AC-DC module 13, the gun A electric energy detection circuit 19 and the gun B electric energy detection circuit 20 sample a voltage value and a current value, when the current value is smaller than 5A, the system control unit MCU101 issues a disconnection instruction to drive the gun A high-voltage direct-current relay 25 and the gun B high-voltage direct-current relay 26 to perform disconnection operation, then the bleeder resistors in the gun A bleeder circuit 17 and the gun B bleeder circuit 18 are started to discharge the voltage value to be below 60V, the electronic lock and the mechanical lock are unlocked, a user can pull the standard national standard A gun 27 and the national standard B gun 28 out of a new energy automobile socket and place the standard A gun and the national standard B gun 28 back on a fixed seat or a socket of the charging pile, and the charging process is ended at this moment.

When a lead-acid charging interface is used for charging a lead-acid system battery, a lead-acid A gun 29 and a lead-acid B gun 30 are firstly connected into a positive port or a negative port or a socket of a lead-acid battery system, at the moment, the voltage state of the lead-acid battery is sampled through an A gun external measurement sampling circuit 22 and a B gun high-voltage direct-current relay 24, a user selects a charging type on a system touch screen to charge the lead-acid battery system, because the lead-acid battery has no internal communication to carry out interaction of a required voltage value and a required current value, the system configuration can obtain battery information in two modes, the first mode is that a user system inputs rated voltage, rated capacity, end voltage and floating charge voltage of the battery system on the touch screen, and the system can automatically store the battery information; secondly, when the user selects charging, the user selects the battery information stored and recorded by the charging pile to be matched with the parameters of the battery system of the user; the charging pile system compares the sampled voltage with the user set parameters to determine whether the parameters are wrong or not, if the set parameters are not matched with the sampled data, charging is not allowed, if the parameters are matched, the system generates a lead-acid battery charging curve as shown in fig. 5 according to the user set parameters, then the charging state is entered, the system control unit MCU101 issues a starting-up working instruction to the gun A AC-DC module 12 and the gun B AC-DC module 13, the gun A AC-DC module 12 and the gun B AC-DC module 13 start working according to the output voltage and the output current required by the instruction, the system control unit MCU101 further issues a closing instruction to drive the gun A high-voltage direct-current relay 25 and the gun B high-voltage direct-current relay 26 to supply power, and at the moment, the system end of the lead-acid battery obtains voltage to be charged.

In the charging process, the voltage value and the current value are sampled in real time through the A gun electric energy detection circuit 19 and the B gun electric energy detection circuit 20, and the output voltage and the output current of the A gun AC-DC module 12 and the B gun AC-DC module 13 are adjusted in real time according to 4 charging stages of trickle charging, constant current charging, constant voltage charging and trickle floating charging by combining a charging curve.

The overall charging ending of the lead-acid battery system is divided into two types: and stopping charging manually and judging by the charging pile to stop charging. After the charging condition is triggered and ended in the charging process, the system control unit MCU101 issues a stop working instruction to the gun A AC-DC module 12 and the gun B AC-DC module 13, the gun A electric energy detection circuit 19 and the gun B electric energy detection circuit 20 sample a voltage value and a current value, when the current value is smaller than 5A, the system control unit MCU101 issues a disconnection instruction to drive the gun A high-voltage direct current relay 25 and the gun B high-voltage direct current relay 26 to perform disconnection operation, then the gun A leakage circuit 17 and the gun B leakage circuit 18 are started, the voltage value is discharged to be below 60V, and then a user can pull the lead-acid A gun 29 and the lead-acid B gun 30 out of the positive port or the negative port or the socket of the lead-acid battery system and place the lead-acid A gun 29 and the lead-acid B gun 30 back to the fixed base or the socket of the charging pile, and the charging process is ended.

When the gun A and the gun B are charged simultaneously, the lead-acid charging interface is used for charging the lead-acid battery system according to the charging process of the lead-acid battery system, and when the national standard direct-current charging gun is used for charging the national standard new energy automobile according to the national standard direct-current charging process, the difference between the simultaneous charging at two sides and the simultaneous charging at one side is that the switching relay 16 is closed when the single-side charging is carried out, the output power of the whole pile can be fully output in the gun at one side, the switching relay 16 is disconnected when the two sides are charged simultaneously, and the output power of the whole pile is averagely distributed to the two charging guns.

Referring to fig. 4, the state transition of the dc charging pile system is described in detail, after the whole system is powered on, the system enters a power-on state, after the system control unit MCU101 starts to work, the system enters a self-checking state, at this time, each unit module in the system is checked for a working state, a communication state, and the like, and if an abnormality is detected in the self-checking process, the system enters a state to be maintained, and waits for maintenance by a professional; if the self-checking process is normal, the system enters a standby state, the charging operation is carried out on a user in the standby state, the system enters a charging state after the user inserts a gun for charging operation, after the charging state triggers charging ending conditions of full charge, user stop and failure, if the charging ending reason is failure stop, the system enters a charging finishing state and then jumps to the failure state, otherwise, the system is maintained in the charging finishing state, and if the user pulls out the charging gun in the state, the system returns to the standby state, and if the national standard new energy automobile BMS control system requests to charge again, the system returns to the charging state. The system enters a standby state when the fault generated in the fault state is recovered to be normal, enters a state to be maintained if the fault state is not recovered for a long time, and enters a power-on state when the system is powered on again after the maintenance of professional personnel is finished in the state to be maintained.

In conclusion, the national standard direct current charging pile system with the lead-acid charging function has the following advantages:

1. the direct-current charging pile system can charge the electric vehicle or equipment using the lead-acid battery, so that the application range of the charging pile is enlarged, and the charging requirement of the electric vehicle or equipment using the lead-acid battery is facilitated;

2. the direct current charging pile system can simultaneously charge a lithium battery conforming to a national standard protocol and an electric vehicle or equipment using a lead-acid battery;

3. the direct current charging pile system can output full power and full load under the working condition of low-voltage output charging, so that charging use of low-voltage charging vehicles is guaranteed;

4. the input cost and the operation and maintenance cost of an operator are reduced, and the operator can meet the charging requirement of an electric vehicle or equipment using the lead-acid battery without additionally arranging a lead-acid charger.

The above description is only a part of or preferred embodiments of the present invention, and neither the text nor the drawings should be construed as limiting the scope of the present invention, and all equivalent structural changes, which are made by using the contents of the present specification and the drawings, or any other related technical fields, are included in the scope of the present invention.