CN113547943A

CN113547943A - Electric automobile exchanges formula and fills electric pile

Info

Publication number: CN113547943A
Application number: CN202110918169.5A
Authority: CN
Inventors: 陈耘
Original assignee: Shanghai Yidong Car Rental Co ltd
Current assignee: Shanghai Yidong Car Rental Co ltd
Priority date: 2021-08-11
Filing date: 2021-08-11
Publication date: 2021-10-26
Anticipated expiration: 2041-08-11
Also published as: CN113547943B

Abstract

The invention provides an alternating current type charging pile for an electric automobile, which comprises a control system, a charging system, a detection system, a communication and display system, a power supply system and a charging interface system. The control system acquires the configuration parameters and reports the running state by using the communication and display system, and controls the charging system to start the charging process of the electric automobile. In the charging process, the control system monitors the charging process by using the detection system and performs feedback control on the charging process by using the charging system; the power supply system provides power for charging the charging pile and the electric vehicle. The detection system comprises a temperature detection module used for reporting the temperature of the charging interface system as an operation state to the control system in the charging process. The charging interface has a simple structure, is convenient to charge, has a perfect over-temperature protection function, can accurately detect the temperature value at the interface and is matched with the over-temperature protection circuit to play a safety protection role, and the working stability of the charging pile system is improved.

Description

Electric automobile exchanges formula and fills electric pile

Technical Field

The invention relates to the field of intelligent charging facilities of electric automobiles, in particular to an alternating current type charging pile for an electric automobile.

Background

In the present day with huge environmental pollution and exhaustion of primary energy, the development of new energy automobile industry becomes a trend. In recent years, new energy electric vehicles are strongly developed, so that charging piles are also vigorously developed as electric energy supplementing devices, and the consumption requirements of people on the charging piles are increasingly increased. As an ac charging pile, the most basic system functions should be provided: the reservation function of charging possesses and detects the vehicle state, possesses and is full of the protection, possesses protection functions such as excessive pressure, undervoltage, overcurrent, possesses measurement charging function, possesses the identification function, possesses data acquisition, remote control function.

But along with the demand is higher and higher more in the development process, fill electric pile and also exposed a great deal of problem: the functions of the alternating-current charging pile system are incomplete, for example, models are not matched, charging time is long, over-temperature protection is blank, and safety factor is low. This brings great challenges to the further development of new energy electric vehicles.

Disclosure of Invention

The invention aims to provide an alternating current type charging pile for an electric automobile, which mainly solves the problems in the prior art and is simple in structure and convenient to charge. Especially, the charging interface has a perfect over-temperature protection function, and the system can be adjusted by the temperature detection of the system and the over-temperature protection circuit under the over-temperature condition caused by the influence factors such as faults, environment and the like, so that a good safety protection effect is achieved.

In order to achieve the purpose, the invention adopts the technical scheme that:

an alternating current type charging pile for an electric automobile is characterized by comprising a control system, a charging system, a detection system, a communication and display system, a power supply system and a charging interface system; the control system acquires configuration parameters and reports an operation state by using the communication and display system, and controls the charging system to start a charging process of the electric automobile; in the charging process, the control system monitors the charging process by using the detection system and performs feedback control on the charging process by using the charging system; the power supply system provides power for the control system, the charging system, the detection system and the communication and display system of the charging pile, and supplies power to the electric automobile through the charging interface system in the charging process; the detection system comprises a temperature detection module used for reporting the temperature of the charging interface system as the running state to the control system in the charging process.

Furthermore, the charging system is composed of a relay driving circuit, a connection detection circuit and an electric energy metering circuit; the relay driving circuit is managed by the control system, the power supply system and a charging loop are connected when the charging process starts, and the power supply system and the charging loop are disconnected when the charging process ends; the connection detection circuit is used for monitoring and acquiring charging state information in the charging process, and the electric energy metering circuit is used for counting electric energy metering in different charging modes in the charging process; and the charging state information and the electric energy metering information belong to the running state and are reported to the control system.

Furthermore, the temperature detection module is composed of a temperature detection circuit and an over-temperature protection circuit which are installed at the charging interface; the temperature detection circuit comprises a thermistor and an analog-to-digital converter; the over-temperature protection circuit comprises a hysteresis generation circuit and an amplification comparator; the voltage change of the thermistor brought by the temperature change is collected by the analog-to-digital converter and then transmitted to the control system; the control system collects the temperature value reported by the temperature detection circuit and outputs a reference voltage corresponding to the temperature threshold value to one input end of the amplification comparator; the voltage of the thermistor, which is brought by the temperature change, simultaneously drives the hysteresis generating circuit to generate currents with different magnitudes; the current of the hysteresis generating circuit is output to the other input end of the amplifying comparator; when the temperature value is larger than a temperature threshold value, the output current of the hysteresis generation circuit enables the amplification comparator to output a signal to the charging system to stop the charging process; when the temperature value is smaller than or equal to the temperature threshold value, the output current of the hysteresis generation circuit enables the amplification comparator to output a signal to the charging system to start the charging process.

Further, the detection system also comprises a leakage detection module and a grounding detection module; when monitoring that the electric leakage or the grounding abnormality is monitored in the charging process, feeding back to the charging system to stop the charging process; the leakage detection module comprises a current transformer and a leakage protection chip which internally comprises a voltage-stabilized power supply amplifying circuit, a comparison circuit, a tripping controller and a tripping driving circuit; a voltage stabilizing circuit and a filter circuit are arranged at the periphery of the leakage protection chip; when a leakage signal is generated, the current transformer outputs an electric signal of the detected leakage current to the leakage protection chip; and when the leakage current is larger than the rated current of the leakage protection chip, the leakage protection chip outputs an action level to the charging system, and the charging process is stopped.

Furthermore, the communication and display system consists of a data storage module, a 4G communication module, a GPRS communication module, an RS485 communication module, an LED display module and an alarm system; the LED display module and the alarm system are used for interacting with an electric vehicle user, and the 4G communication module and the GPRS communication module are used for interacting with a background control system; the RS485 is used for information interaction between the control system and the charging system; the data storage module provides data support for interaction with the electric vehicle user and the background control system.

Further, the power supply system comprises a PWM controller, a MOSFET controlled by the PWM controller, an input module at one side of the transformer and an output module at the other side of the transformer; the input module comprises a rectifying circuit and a high-voltage resistant circuit; after passing through the rectifying circuit and the high-voltage resistant circuit, 220V alternating current is connected to a high-voltage starting end of the PWM controller; a power supply for supplying power to the PWM controller is led out from the secondary winding of the transformer; the PWM controller controls the current and voltage of the secondary coil of the transformer by adjusting the current and voltage in the primary coil of the transformer by using the MOSFET; and the output module filters the current in the secondary coil and supplies the filtered current to the electric automobile for charging.

Further, the power supply system further comprises a photoelectric coupler; setting a sampling resistor in the output module; the voltage signal on the sampling resistor is amplified and then input to the control system; the input end of the photoelectric coupler is driven by the control system, and the output end of the photoelectric coupler is connected with the PWM controller; when the control system detects that the charging process enters trickle charging, the control system controls the voltage of the input end of the photoelectric coupler to reduce the output voltage of the photoelectric coupler, so that the PWM controller outputs narrow pulses, and the current and the voltage in the primary coil are reduced through the MOSFET.

Furthermore, the control system comprises an MCU (microprogrammed control unit), and the management of charging the electric automobile is completed by utilizing a charging control unit, a human-computer interaction unit and a networking monitoring unit which are operated on the MCU; the charging control unit completes system initialization, pile machine communication, charging mode selection and user identity identification by utilizing the input of the human-computer interaction unit and matching with the charging system, the detection system and the power supply system, and performs electric quantity metering work after the charging process is started; the human-computer interaction unit and the networking monitoring unit finish user identity identification, expense settlement and remote monitoring by utilizing the communication and display system.

Further, the charging mode selection comprises automatic full charging, charging according to time and charging according to electric quantity.

Furthermore, the control system comprises an MCU, and the monitoring of the charging process of the electric automobile is completed by utilizing a fault protection unit operated on the MCU; the fault protection unit is matched with the detection system to realize the safety protection function.

Further, the fault protection unit continuously reads a temperature value reported by the analog-to-digital converter, and drives the hysteresis generation circuit to generate a small current when the temperature value is less than or equal to a temperature threshold value; when the temperature value is larger than the temperature threshold value, driving the hysteresis generation circuit to generate large current; under the driving of the small current, the amplification comparator outputs a low-level signal, so that the charging system is connected with a charging loop; under the drive of the large current, the amplification comparator outputs a high-level signal, so that the charging system disconnects the charging loop.

In view of the above technical features, the present invention has the following advantages: temperature value and the cooperation excess temperature protection circuit of detection department kneck that can be more accurate play the safety protection effect, improve the job stabilization nature of filling the electric pile system.

Drawings

Fig. 1 is a system structure diagram of an electric vehicle ac charging pile according to a preferred embodiment of the present invention;

FIG. 2 is a hardware configuration diagram of an electric vehicle AC charging pile according to a preferred embodiment of the present invention;

FIG. 3 is a circuit diagram of the leakage detection of the AC charging post of the electric vehicle according to the preferred embodiment of the present invention;

FIG. 4 is a circuit diagram of a temperature detection circuit of an AC charging post for an electric vehicle according to a preferred embodiment of the present invention;

FIG. 5 is a circuit diagram of an over-temperature protection circuit of an AC charging post for an electric vehicle according to a preferred embodiment of the present invention;

FIG. 6 is a block diagram of a power system of an AC charging post for an electric vehicle according to a preferred embodiment of the present invention;

FIG. 7 is a software flowchart of a charging process of an AC charging post for an electric vehicle according to a preferred embodiment of the present invention;

fig. 8 is a flowchart of the over-temperature protection software of the ac charging pile for the electric vehicle according to the preferred embodiment of the invention.

In the figure: 100-control system, 200-charging system, 300-detection system, 400-communication and display system, 500-power system, 600-charging interface system, 700-commercial power;

3001-current transformer, 3002-earth leakage protection chip, 3003-voltage dependent resistor, 3004-capacitor; 3011-thermistor, 3012-hysteresis generation circuit, 3013-amplification comparator.

Detailed Description

The invention will be further illustrated with reference to specific embodiments. It should be understood that these examples are for illustrative purposes only and are not intended to limit the scope of the present invention. Further, it should be understood that various changes or modifications of the present invention may be made by those skilled in the art after reading the teaching of the present invention, and such equivalents may fall within the scope of the present invention as defined in the appended claims.

Referring to fig. 1, the invention discloses an alternating current charging pile for an electric vehicle. As shown, a preferred embodiment of the present invention includes a control system 100, a charging system 200, a detection system 300, a communication and display system 400, a power supply system 500, and a charging interface system 600. The input end of the power system of the electric vehicle ac charging pile of this embodiment is connected to the commercial power 700, and the output end is installed with the charging interface system 600 to connect the electric vehicle for charging. The electric pile that fills of this embodiment belongs to conventional charging mode, and alternating current operating voltage is 220V 5%, quota output power 3.5KW, 7KW, is applicable to the power battery that slowly charges.

The communication and display system 400 is responsible for completing a human-computer interaction interface, and can interact with a user of the electric vehicle to acquire parameters such as identity information and a charging mode and feed back a charging state, and also interact with a remote management system to report a system state and receive a remote control command. The control system 100 obtains the configuration parameters or remote control commands input by the user from the communication and display system 400, further manages the charging pile working mode, and reports the system running state by using the communication and display system 400. The control system 100 controls the charging process of the electric vehicle by switching on or off the charging loop of the electric vehicle through the charging system 200. During the charging process, the detection system 300 continuously monitors the charging process. For an abnormal event with high risk, the detection system 300 directly feeds back to the charging system 200 to cut off the charging loop. For other abnormal events, the detection system 300 reports to the control system 100, and the control system 100 determines the subsequent processing mode, such as whether to stop the charging process, or not, by itself or by interaction with a user or a remote control. The power system 500 has two purposes, one is to provide power support for each module of the charging pile system, including the control system 100, the charging system 200, the detection system 300, and the communication and display system 400, to ensure that these modules work normally. The other is to provide charging power to the electric vehicle through the charging interface system 600.

Referring to fig. 2, a core component of the control system 100 is a single chip Microcomputer (MCU), which is a chip-level computer formed by integrating a CPU, a memory, various I/O interfaces, and the like on one chip. Charging system 200

The charging system 200 is composed of a relay drive circuit, a connection detection circuit, and an electric energy metering circuit. The relay drive circuit is managed by the control system 100, and connects the power supply system 500 to the charging circuit at the start of the charging process, and disconnects the power supply system 500 from the charging circuit at the end of the charging process. In the charging process, the connection detection circuit monitors and collects charging state information, and the electric energy metering circuit counts electric energy metering in different charging modes. The charging state information and the electric energy metering information are reported to the control system 100 in the form of the running state, so that functions such as charging state prompt, charge settlement and the like are completed.

In this embodiment, the detection portion 300 is used for carrying out each item of safety detection to charging pile system to and the safety protection work, comprises ground connection detection module, electric leakage detection module and temperature detection module triplex. When a poor grounding or leakage condition is monitored during the charging process, the grounding detection module or the leakage detection module directly feeds back to the charging system 200 to stop the charging process.

The temperature detection module is disposed at the charging interface system 600, and configured to report the acquired temperature information as an operating state to the control system 100 in the charging process, and further process the temperature information by the control system 100.

The communication and display system 400 is composed of a data storage module, a 4G communication module, a GPRS communication module, an RS485 communication module, an LED display module and an alarm system, and is used for communicating with a background control system and a user terminal for the electric vehicle to realize functions of vehicle charging parameter matching, user identity identification, charging real-time monitoring, electric energy metering and the like. The LED display module and the alarm system are used for interacting with an electric automobile user, the 4G communication module and the GPRS communication module are used for interacting with a background control system, and the RS485 communication module is used for information interaction between an electric energy meter (a component of an electric energy metering circuit in the charging system 200) in the charging pile and the control system 100 (MCU). The data storage module provides support for the data interaction.

The power supply system 500 is a MOSFET controlled by pwm, and is used to rectify the ac power of the utility power 700 into dc power and maintain a stable output voltage, and is provided to the electric vehicle through the charging connection system 600 for charging.

Referring to fig. 3, the leakage detecting module includes a current transformer 3001 and a leakage protection chip 3002 (model VG54123A) including a voltage-stabilized power amplifier circuit, a comparator circuit, a trip controller, and a trip driving circuit therein. The chip is composed of eight pins, In1, In2, VSS, OA, Dly, OS, VDD, NC. The following outlines the respective pin functions:

in1 and In2 are amplifier input ends;

VSS is ground wire;

OA is the output of the internal amplifier and is externally connected with a filter capacitor;

dly is delay adjustment, external capacitor;

OS is the trip signal output;

VDD is a power line;

NC has no connection.

Two devices which are connected in parallel in an inverse manner, such as a voltage stabilizing diode 3003 used as a voltage stabilizing circuit, a voltage dependent resistor, a capacitor 3004 used as an input signal filter circuit and the like are arranged at the periphery of the leakage protection chip.

When a leakage signal is generated, the current transformer 3001 detects a leakage current and outputs the leakage current to the In1 and In2 pins of the leakage protection chip 3002. When the leakage current is larger than the rated current of the leakage protection chip 3002, the amplifier signal inside the leakage protection chip 3002 is inverted, and finally the OS outputs an action level to the charging system to control the charging system to trip, thereby stopping the charging process.

Referring to fig. 4 and 5, the temperature detection module is composed of a temperature detection circuit and an over-temperature protection circuit installed at the charging interface. The temperature detection circuit includes a thermistor 3011 and an analog-to-digital converter, as shown in fig. 3. The real-time temperature at the thermistor induction charging interface is specifically realized as follows: when the temperature changes, the resistance value of the thermistor changes, so that the voltage Tem at the input end of the analog-to-digital converter changes. The analog-to-digital converter collects the voltage signal of the input end, converts the voltage signal into a digital signal and reports the digital signal to the control system.

The over-temperature protection circuit (shown in fig. 4) includes a hysteresis generation circuit 3012 and an amplification comparator 3013. The driving hysteresis generating circuit 3012 is driven by a temperature detecting circuit composed of thermistors, generates currents of different magnitudes as the temperature detecting circuit detects different temperatures, is grounded through a triode, and then is input to the negative terminal of the amplifying comparator 3013. In the control system (i.e., MCU), the temperature value reported by the temperature detection circuit and the current value corresponding to the hysteresis generation circuit 3012 are collected in advance to form a lookup table. In the operating mode, the control system takes the temperature threshold (determined by the background control system) as an input, finds the value of the reference voltage corresponding to the temperature threshold by looking up the table comparison, and then drives the output to the positive terminal (VREF2) of the amplified comparator 3013.

When the temperature value is greater than the temperature threshold, the output current of the hysteresis generation circuit 3012 causes the negative terminal voltage of the amplified comparator 3013 to be lower than the positive terminal voltage (VREF2), and the amplified comparator 3013 outputs a high level to the charging system to stop the charging process. When the temperature is lower than a temperature threshold (determined by a background control system), the output current of the hysteresis generation circuit 3012 makes the negative terminal voltage of the amplification comparator 3013 higher than the positive terminal voltage (VREF2), that is, the amplification comparator 3013 outputs a low level, and the charging system turns on the charging loop to charge the electric vehicle. The temperature threshold is set to 150 deg.c in this embodiment.

Referring to fig. 6, the power supply system includes a PWM controller, a MOSFET connected and controlled by the PWM controller, an input module at one side of the transformer, and an output module at the other side. The input module comprises a rectifying circuit formed by four rectifying diodes and a high-voltage resistant circuit formed by two 400V/10 mu F aluminum electrolytic capacitors connected in series. Each capacitor can withstand up to 450V. The two capacitors are connected in series, so that the whole circuit can endure the maximum voltage of 900V. In addition, the electrolytic capacitor can also play a role in further filtering and smoothing output pulse signals by storing and releasing charges.

The PWM controller is a highly integrated and low start-up current GR8876N chip consisting of eight pins, RTL, COMP, CS, GND, OUT, VCC, NC, HV respectively. The following outlines the respective pin functions:

RTL: an auto recovery/latch trigger pin with OVP lock closure auto recovery above 3.5V and OTP latch auto recovery below 1.05V.

COMP: a voltage feedback pin for controlling duty ratio by connecting a photoelectric coupler

CS: a current detection pin connected to detect MOSFET current

GND: ground connection

OUT: output driver for driving external MOSFET

VCC: power supply pin

NC: unconnected pin

HV: the pin provides the start-up current, and when tripped (on), the high voltage loop will close and limit the power loss on the start-up circuit.

The utility model discloses in utilize this chip as switching power supply's driver chip, make its powerful functional characteristic of performance, steerable 65KHz switching frequency that has the shake in green mode operation process to reduce electromagnetic interference. The chip has a plurality of protection and detection compensation functions at the same time.

After passing through the rectifying circuit and the high-voltage resistant circuit, the 220V alternating current is connected to a high-voltage starting end (HV pin) of the PWM controller. The power supply (VCC) of the PWM controller comes from the secondary winding (13-15V) of the transformer. When the voltage on VCC is stable, the high voltage start-up circuit may automatically shut down. The OUT pin of the PWM controller is connected with the MOSFET, the MOSFET is turned on when OUT is in a high level, and the MOSFET is turned off when OUT is in a low level, so that the average current and voltage of the secondary coil of the transformer are controlled by adjusting the average current and voltage of the primary coil of the transformer. The output module filters the current in the secondary coil and then accesses the charging loop, and when the charging loop is switched on under the control of the charging system, the charging and discharging can be carried out on the electric automobile.

The power supply system further comprises a photoelectric coupler. The whole charging process of the automobile battery comprises pre-charging, quick charging, trickle charging and supplementary charging. Wherein the fast charging phase uses constant current charging. In the constant-current charging process, the charging current generates voltage drop on the sampling resistor, the voltage signal is transmitted to the MCU after being amplified, and the control signal is fed back to the preceding stage circuit through the photoelectric coupler after being processed by the MCU. Namely, the input end of the photoelectric coupler is controlled by the MCU, and the output end of the photoelectric coupler is connected with the PWM controller.

The MCU is also preset with a trickle charge threshold voltage. When the charging of the electric automobile enters trickle charging, the voltage drop on the sampling resistor is reduced, and when the voltage signal input to the MCU is lower than the threshold voltage, the MCU controls the output voltage of the photoelectric coupler to be reduced, namely the voltage of a COMP pin of the PWM controller is reduced, so that the pulse on the OUT pin is narrowed. The narrow pulse causes the MOSFET on-time to become short and the average current in the primary winding drops and feeds back to the secondary winding, causing the current and voltage at the output to drop to match the trickle charge requirement.

Referring to fig. 7, the control system completes management of charging the electric vehicle by using the charging control unit, the human-computer interaction unit and the networking monitoring unit which are operated on the MCU; the charging control unit waits for the automobile BMS to send a charging request to the charging pile, starts a charging mode after receiving the charging request, firstly performs analog-digital sampling to enter the charging mode, and then performs insulation detection to start the switching power supply module. During the entire charging process. And after the power module finishes charging, the state feedback is carried out, and at the moment, the system closes the charging process.

The man-machine interaction unit is communicated with the card reading panel and the electric energy metering system to carry out user identity identification and expense settlement. The charging state of the charging pile is represented by the fact that an LED indicator lamp of the charging pile control panel is turned on or off. And the networking monitoring unit is used for receiving and transmitting data by the control panel through the local area network and the background control system under a corresponding communication protocol in the whole charging process so as to realize remote monitoring of the charging pile.

The charging control unit is activated and started by the connection of the automobile and the charging interface of the charging gun (step S101), and then after the system initialization is completed (step S102), the pile machine communication is started. The pile machine communication mainly comprises the acquisition of relevant parameter information such as automobile charging current, voltage and the like, and comprises the detection of the signal state of a charging gun charging interface (step S103) and the communication butt joint with an electric automobile (step S104). When the communication result of the pile machine meets the preset condition, the charging control unit starts user identification by using the human-computer interaction unit (step S105). If the user' S identification card authentication (step S106) fails, it returns to step S105 to continue waiting for a valid card. If the identity card passes the authentication, the charging control unit waits for the charging mode selection of the electric vehicle user by using the man-machine interaction unit (step S107). The electric vehicle user can select automatic full charge (step S1071), charging by time (step S1072), or charging by electric quantity (step S1073). After the electric vehicle user selects a charging mode, the charging control unit cooperates with the charging system, the detection system and the power supply system to enter a charging process.

After the charging process is started, the charging control unit starts to measure the electric quantity (step S108), including the real-time monitoring of the interaction function of the charging pile and the automobile and the whole charging process. The charging circuit is first turned on to start charging (step S109), and then the charging termination condition is continuously detected (step S110). When the termination condition is satisfied, the charging control unit opens the contactor (step S111), and then performs a deduction settlement after the termination of charging (step S112). In the settlement process, the charging control unit and the networking monitoring unit interact with the electric vehicle user by utilizing the communication and display system. After the electric vehicle user finishes the settlement, the software flow is ended after waiting for the electric vehicle user to pull the gun (step S113).

Referring to fig. 8, the control system completes monitoring of the charging process of the electric vehicle by using the fault protection unit operating on the MCU. The fault protection unit is matched with the detection system, and takes various fault types into consideration, and corresponding fault detection programs are written in advance. When a fault occurs, the fault type can be firstly identified and judged through the fault detection system, and then a corresponding fault protection program is executed, so that a reliable safety protection function is realized.

In the fault protection unit, protection software for over-temperature protection of the charger interface is activated when the system is in a charging state of abnormal operation (step S201). The thermistor arranged at the charging interface system detects the current environment temperature in real time (step S202), on one hand, the temperature value is reported to the MCU through the analog-to-digital converter, on the other hand, the hysteresis generating circuit is driven to output current, and the voltage input of the negative terminal of the amplifier is formed through the triode. In the MCU, there is a table of temperature values versus output current of the hysteresis generation circuit (i.e., the amplifier negative terminal voltage). When the user determines the temperature threshold, the amplifier positive terminal voltage is derived from this table and driven by the MCU to the positive terminal of the amplifier. When the real-time temperature exceeds the preset value of 150 ℃, the negative terminal voltage formed by the current output by the hysteresis generation circuit is greater than the positive terminal voltage driven by the MCU. On the contrary, when the real-time temperature is less than or equal to the preset value of 150 ℃, the negative terminal voltage formed by the current output by the hysteresis generating circuit is less than the positive terminal voltage driven by the MCU (step S203). The amplified comparator determines whether the negative terminal real-time voltage is greater than a preset value (positive terminal voltage) (step S204), and if so, the amplified comparator outputs a low level and returns to step S201 to continue normal charging. If the current value is less than the preset value, the amplifying comparator outputs a high level to drive the charging system to close the charging loop (step S205), so that the charging process is stopped (step S206), and the step S202 is returned to continue to collect the real-time temperature. And when the temperature value at the interface to be charged is lower than the critical value of 150 degrees, the charging system is switched on the charging loop again, and the charging is recovered.

The above description is only a preferred embodiment of the present invention, and not intended to limit the scope of the present invention, and all modifications of equivalent structures and equivalent processes, which are made by using the contents of the present specification and the accompanying drawings, or directly or indirectly applied to other related technical fields, are included in the scope of the present invention.

Claims

1. An alternating current type charging pile for an electric automobile is characterized by comprising a control system, a charging system, a detection system, a communication and display system, a power supply system and a charging interface system; the control system acquires configuration parameters and reports an operation state by using the communication and display system, and controls the charging system to start a charging process of the electric automobile; in the charging process, the control system monitors the charging process by using the detection system and performs feedback control on the charging process by using the charging system; the power supply system provides power for the control system, the charging system, the detection system and the communication and display system of the charging pile, and supplies power to the electric automobile through the charging interface system in the charging process; the detection system comprises a temperature detection module used for reporting the temperature of the charging interface system as the running state to the control system in the charging process.

2. The electric vehicle alternating-current charging pile according to claim 1, wherein the charging system is composed of a relay driving circuit, a connection detection circuit and an electric energy metering circuit; the relay driving circuit is managed by the control system, the power supply system and a charging loop are connected when the charging process starts, and the power supply system and the charging loop are disconnected when the charging process ends; the connection detection circuit is used for monitoring and acquiring charging state information in the charging process, and the electric energy metering circuit is used for counting electric energy metering in different charging modes in the charging process; and the charging state information and the electric energy metering information belong to the running state and are reported to the control system.

3. The electric vehicle alternating-current charging pile according to claim 1, wherein the temperature detection module is composed of a temperature detection circuit and an over-temperature protection circuit which are installed at a charging interface; the temperature detection circuit comprises a thermistor and an analog-to-digital converter; the over-temperature protection circuit comprises a hysteresis generation circuit and an amplification comparator; the voltage change of the thermistor brought by the temperature change is collected by the analog-to-digital converter and then transmitted to the control system; the control system collects the temperature value reported by the temperature detection circuit and outputs a reference voltage corresponding to the temperature threshold value to one input end of the amplification comparator; the voltage of the thermistor, which is brought by the temperature change, simultaneously drives the hysteresis generating circuit to generate currents with different magnitudes; the current of the hysteresis generating circuit is output to the other input end of the amplifying comparator; when the temperature value is larger than a temperature threshold value, the output current of the hysteresis generation circuit enables the amplification comparator to output a signal to the charging system to stop the charging process; when the temperature value is smaller than or equal to the temperature threshold value, the output current of the hysteresis generation circuit enables the amplification comparator to output a signal to the charging system to start the charging process.

4. The electric vehicle alternating-current charging pile according to claim 1, wherein the detection system further comprises an electric leakage detection module and a grounding detection module; when monitoring that the electric leakage or the grounding abnormality is monitored in the charging process, feeding back to the charging system to stop the charging process; the leakage detection module comprises a current transformer and a leakage protection chip which internally comprises a voltage-stabilized power supply amplifying circuit, a comparison circuit, a tripping controller and a tripping driving circuit; a voltage stabilizing circuit and a filter circuit are arranged at the periphery of the leakage protection chip; when a leakage signal is generated, the current transformer outputs an electric signal of the detected leakage current to the leakage protection chip; and when the leakage current is larger than the rated current of the leakage protection chip, the leakage protection chip outputs an action level to the charging system, and the charging process is stopped.

5. The electric vehicle alternating-current charging pile according to claim 1, wherein the communication and display system is composed of a data storage module, a 4G communication module, a GPRS communication module, an RS485 communication module, an LED display module and an alarm system; the LED display module and the alarm system are used for interacting with an electric vehicle user, and the 4G communication module and the GPRS communication module are used for interacting with a background control system; the RS485 is used for information interaction between the control system and the charging system; the data storage module provides data support for interaction with the electric vehicle user and the background control system.

6. The electric vehicle alternating-current charging pile according to claim 1, wherein the power supply system comprises a PWM controller, a MOSFET controlled by the PWM controller, an input module on one side of the transformer and an output module on the other side of the transformer; the input module comprises a rectifying circuit and a high-voltage resistant circuit; after passing through the rectifying circuit and the high-voltage resistant circuit, 220V alternating current is connected to a high-voltage starting end of the PWM controller; a power supply for supplying power to the PWM controller is led out from the secondary winding of the transformer; the PWM controller controls the current and voltage of the secondary coil of the transformer by adjusting the current and voltage in the primary coil of the transformer by using the MOSFET; and the output module filters the current in the secondary coil and supplies the filtered current to the electric automobile for charging.

7. The electric vehicle ac charging pile according to claim 6, wherein the power supply system further comprises an opto-coupler; setting a sampling resistor in the output module; the voltage signal on the sampling resistor is amplified and then input to the control system; the input end of the photoelectric coupler is driven by the control system, and the output end of the photoelectric coupler is connected with the PWM controller; when the control system detects that the charging process enters trickle charging, the control system controls the voltage of the input end of the photoelectric coupler to reduce the output voltage of the photoelectric coupler, so that the PWM controller outputs narrow pulses, and the current and the voltage in the primary coil are reduced through the MOSFET.

8. The electric vehicle alternating-current charging pile according to claim 1, wherein the control system comprises an MCU (microprogrammed control unit), and management of electric vehicle charging is completed by utilizing a charging control unit, a human-computer interaction unit and a networking monitoring unit which are operated on the MCU; the charging control unit completes system initialization, pile machine communication, charging mode selection and user identity identification by utilizing the input of the human-computer interaction unit and matching with the charging system, the detection system and the power supply system, and performs electric quantity metering work after the charging process is started; the human-computer interaction unit and the networking monitoring unit finish user identity identification, expense settlement and remote monitoring by utilizing the communication and display system.

9. The electric vehicle ac charging pile according to claim 8, wherein the charging mode selection comprises auto-charging, charging according to time, and charging according to quantity of electricity.

10. The electric vehicle alternating-current charging pile according to claim 3, wherein the control system comprises an MCU (microprogrammed control unit), and the fault protection unit operated on the MCU is used for monitoring the charging process of the electric vehicle; the fault protection unit is matched with the detection system to realize the safety protection function.

11. The electric vehicle alternating-current charging pile according to claim 10, wherein the fault protection unit continuously reads a temperature value reported by the analog-to-digital converter, and drives the hysteresis generation circuit to generate a small current when the temperature value is less than or equal to a temperature threshold value; when the temperature value is larger than the temperature threshold value, driving the hysteresis generation circuit to generate large current; under the driving of the small current, the amplification comparator outputs a low-level signal, so that the charging system is connected with a charging loop; under the drive of the large current, the amplification comparator outputs a high-level signal, so that the charging system disconnects the charging loop.