CN113335095A - Vehicle-mounted fast and slow charging integrated charging system and method for low-voltage platform electric vehicle - Google Patents

Abstract

The invention provides a vehicle-mounted fast and slow charging integrated charging system and method for a low-voltage platform electric vehicle, aiming at the problem of charging convenience of the low-voltage platform electric vehicle at the present stage, a specific charging device and a control method are adopted, so that the function of charging the low-voltage platform electric vehicle in a conventional fast charging pile is realized, and the use convenience of the low-voltage platform electric vehicle is greatly improved. According to the invention, the low-voltage platform electric vehicle is supported to use the slow charging pile to perform high-efficiency safe charging through the slow charging working mode, so that the charging compatibility of the low-voltage platform electric vehicle charging system is effectively improved.

Description

Vehicle-mounted fast and slow charging integrated charging system and method for low-voltage platform electric vehicle

Technical Field

The invention belongs to the technical field of electric automobile charging, and particularly relates to a vehicle-mounted quick-slow charging integrated charging system and method for a low-voltage platform electric vehicle.

Background

In order to meet customer requirements and low-cost development requirements of specific electric automobiles, electric automobiles with low-voltage platforms (electric automobiles with power battery voltage ranges smaller than 200V) need to be developed, but at the present stage, the lowest output voltage of domestic general quick charging piles is larger than 200V, the charging requirements of vehicles with low-voltage platforms cannot be supported, the charging convenience is greatly influenced, and therefore the problem that the universal quick charging piles cannot be used for charging is required to be solved for the development of the low-voltage electric automobiles.

In the conventional vehicle-mounted charger for the electric automobile, the charging method and the electric automobile, compatible alternating current slow charging and direct current fast charging are realized by additionally arranging a boost DC-DC (when direct current fast charging is adopted, 12V provided by a storage battery is converted into high voltage, such as 400V, by using the boost DC-DC for enabling a direct current charging interface to have preset high voltage so as to meet the polarity detection requirement between a direct current fast charging pile and the direct current charging interface). However, the prior art has the following defects:

1. the circuit topology is free of a PFC (power factor correction) circuit and a power factor correction function, and the lower the power utilization rate is when alternating current is charged at a low speed, the lower the conversion efficiency of the whole machine is;

2. in the alternating-current slow charging process, 220V alternating current passes through a rectifier bridge and then is connected with a direct-current charging interface, so that direct-current high-voltage electricity always exists in the direct-current charging interface in the slow charging process, the electric shock risk exists, and huge potential safety hazards exist;

3. a Battery Management System (BMS) is integrated in the vehicle-mounted charger and shares a CPU controller, and the CPU controller is in a working state in the charging and driving processes, so that the service life is influenced, and the fault rate is increased; in addition, the Battery Management System (BMS) and each detection circuit or sensor in the battery pack need to be in communication connection through a large number of low-voltage signal harnesses, the Battery Management System (BMS) is outside the battery pack, so that the design of the whole vehicle harness is difficult, the reliability is reduced, the cost is increased, transmitted signals are easily interfered, and the use safety is affected.

In addition, a high-adaptability charging system and method for the electric automobile disclose the idea of multiple charging modes; however, this prior art only discloses that a battery management system is used to manage a positive relay in a normal charging mode, a positive relay in a high-voltage charging mode, and a positive relay in a low-voltage charging mode to realize charging in different modes, and does not disclose a specific structure of a circuit in each charging mode, nor a charging structure in a slow charging mode and a fast charging mode for a low-voltage electric vehicle.

Disclosure of Invention

The technical problem to be solved by the invention is as follows: the vehicle-mounted fast and slow charging integrated charging system and method for the low-voltage platform electric vehicle are used for achieving the function of charging the low-voltage platform electric vehicle in a conventional fast charging pile.

The technical scheme adopted by the invention for solving the technical problems is as follows: a vehicle-mounted fast and slow charging integrated charging system of a low-voltage platform electric vehicle comprises a vehicle fast charging socket, a vehicle slow charging socket, a vehicle-mounted fast and slow charging integrated charging device, a power battery and a storage battery; the vehicle-mounted quick and slow charging integrated charging device comprises a charging control unit, a DC/DC boosting module, an AC/DC conversion module, a DC/DC voltage reduction module, a first switch, a second switch and a third switch; the energy input end of the vehicle quick charging socket is connected with the quick charging pile; the energy output end of the vehicle fast charging socket is sequentially connected with the energy input end of the second switch and the energy input end of the DC/DC voltage reduction module in series through the direct current input interface of the vehicle-mounted fast and slow charging integrated charging device; the signal end of the vehicle quick-charging socket is connected with the charging control unit through a low-voltage interface of the vehicle-mounted quick-slow charging integrated charging device; the vehicle quick-charging socket is used for sending a quick-charging signal to the charging control unit when the quick-charging pile is communicated, and transmitting high-voltage direct current output by the quick-charging pile to the DC/DC voltage reduction module, so that the vehicle-mounted quick-slow charging integrated charging device enters a quick-charging working mode and controls input voltage and current; the energy input end of the vehicle slow charging socket is connected with the slow charging pile; the energy output end of the vehicle slow charging socket is connected with the energy input end of the AC/DC conversion module in series through the alternating current input interface of the vehicle-mounted fast and slow charging integrated charging device; the signal end of the vehicle slow charging socket is connected with the charging control unit through a low-voltage interface of the vehicle-mounted fast and slow charging integrated charging device; the vehicle slow charging socket is used for sending a slow charging signal to the charging control unit when the slow charging pile is communicated, and transmitting alternating current output by the slow charging pile to the AC/DC conversion module, so that the vehicle-mounted fast and slow charging integrated charging device enters a slow charging working mode and controls input current; the control end of the charging control unit is respectively connected with the signal end of the AC/DC conversion module, the signal end of the DC/DC voltage reduction module and the signal end of the DC/DC voltage boosting module and is used for respectively sending driving signals to the AC/DC conversion module, the DC/DC voltage reduction module and the DC/DC voltage boosting module; the energy output end of the storage battery is respectively connected with the energy input ends of the charging control unit and the DC/DC boosting module and is respectively used for supplying power to the charging control unit and the DC/DC boosting module; the energy output end of the DC/DC boosting module is connected with a quick charging pile through a third switch, a direct-current input interface of the vehicle-mounted quick-slow charging integrated charging device and a vehicle quick-charging socket; the DC/DC boosting module is used for converting low-voltage direct current output by the storage battery into high-voltage direct current according to a driving signal of the charging control unit and transmitting the high-voltage direct current to the quick charging pile so as to simulate the voltage of the vehicle end required to be detected when the quick charging pile is started; the energy output end of the AC/DC conversion module is connected with the energy input end of the DC/DC voltage reduction module through a first switch; the AC/DC conversion module is used for converting the alternating current output by the slow charging pile into direct current according to a driving signal of the charging control unit and transmitting the direct current to the DC/DC voltage reduction module; the energy output end of the DC/DC voltage reduction module is connected with the energy input end of the power battery through the direct current output interface of the vehicle-mounted fast and slow charging integrated charging device; the DC/DC voltage reduction module is used for converting the high-voltage direct current output by the quick charging pile or the direct current output by the AC/DC module into low-voltage direct current matched with the requirement of the power battery according to the driving signal of the charging control unit and transmitting the low-voltage direct current to the power battery.

According to the scheme, the power battery comprises a battery management unit; the signal end of the battery management unit is connected with the charging control unit through a low-voltage interface of the vehicle-mounted quick and slow charging integrated charging device; the battery management unit is used for sending signals including the charging permission voltage, the charging permission current and the SOC of the power battery to the charging control unit so as to control the voltage and the current output by the vehicle-mounted quick-slow charging integrated charging device.

Furthermore, the charging control unit comprises a plugging detection circuit, an MCU control circuit and a DSP control circuit; the inserting and robbing detection circuit is used for detecting a slow charging signal or a fast charging signal and outputting a high level signal to wake up the MCU control circuit and the DSP control circuit when the slow charging signal or the fast charging signal is detected; the MCU control circuit is used for receiving a fast charge signal or a slow charge signal, receiving signals including an allowable charge voltage, an allowable charge current and an SOC of the power battery after being awakened by the plugged robbing detection circuit, and sending signals including a fast charge working mode or a slow charge working mode, an input voltage limit value and an input current limit value to the DSP control circuit; the DSP control circuit is used for receiving signals including a fast charge working mode or a slow charge working mode, an input voltage limit value, an input current limit value, an output voltage and an output current after being awakened by the inserted robbing detection circuit, and respectively sending driving signals to the DC/DC boosting module, the AC/DC conversion module and the DC/DC voltage reduction module.

Further, the DC/DC boost module comprises an inverter circuit and a rectifying circuit; the inverter circuit is used for converting the low-voltage direct current output by the storage battery into alternating current according to the driving signal sent by the DSP control circuit and outputting the alternating current to the rectifying circuit; the rectification circuit is used for converting alternating current output by the inverter circuit into high-voltage direct current and transmitting the high-voltage direct current to the quick-charging pile, and the voltage of the vehicle end required to be detected when the quick-charging pile is started is simulated.

Further, the AC/DC conversion module comprises a filter circuit and a bridgeless PFC circuit; the filter circuit is used for filtering ripples in alternating current output by the slow charging pile; the bridgeless PFC circuit is used for converting alternating current passing through the filter circuit into direct current according to a driving signal sent by the DSP control circuit, correcting power factors and outputting the direct current to the DC/DC voltage reduction module.

Further, the DC/DC voltage reduction module comprises an inverter circuit and a rectification circuit; the inverter circuit is used for converting the high-voltage direct current output by the quick charging pile or the direct current output by the AC/DC module into alternating current according to a driving signal sent by the DSP control circuit and outputting the alternating current to the rectifying circuit; the rectification circuit is used for converting alternating current output by the inverter circuit into low-voltage direct current according to a driving signal sent by the DSP control circuit and outputting the low-voltage direct current to the power battery.

According to the scheme, the charging device further comprises a slow charging alternating current input loop formed by the first high-voltage cable group, and the slow charging alternating current input loop is used for connecting the vehicle slow charging socket and an alternating current input interface of the vehicle-mounted fast and slow charging integrated charging device; the quick charging direct current input loop is formed by the second high-voltage cable group and is used for connecting a vehicle quick charging socket and a direct current input interface of the vehicle-mounted quick and slow charging integrated charging device; the direct current output loop is formed by a third high-voltage cable group and is used for connecting a direct current output interface of the vehicle-mounted quick and slow charging integrated charging device and an energy input end of the power battery; the slow charging signal transmission line is formed by the first low-voltage cable group and used for connecting a signal end of the vehicle slow charging socket with the charging control unit; the quick-charging signal transmission line is formed by the second low-voltage cable group and used for connecting a signal end of the vehicle quick-charging socket with the charging control unit; the third low-voltage cable group forms a CAN communication signal transmission line for connecting a battery management unit and a charging control unit of the power battery; and the power line formed by the fourth low-voltage cable group is used for respectively connecting the energy output end of the storage battery with the energy input end of the charging control unit and the energy input end of the DC/DC boosting module.

A vehicle-mounted fast and slow charging integrated charging method for a low-voltage platform electric vehicle comprises the following steps:

s1: the method comprises the steps that a vehicle-mounted fast and slow charging integrated charging system of the low-voltage platform electric vehicle is built, and the vehicle-mounted fast and slow charging integrated charging system comprises a vehicle fast charging socket, a vehicle slow charging socket, a vehicle-mounted fast and slow charging integrated charging device, a power battery and a storage battery; the vehicle-mounted quick and slow charging integrated charging device comprises a charging control unit, a DC/DC boosting module, an AC/DC conversion module, a DC/DC voltage reduction module, a first switch, a second switch and a third switch; the energy input end of the vehicle quick charging socket is connected with the quick charging pile; the energy output end of the vehicle fast charging socket is sequentially connected with the energy input end of the second switch and the energy input end of the DC/DC voltage reduction module in series through the direct current input interface of the vehicle-mounted fast and slow charging integrated charging device; the signal end of the vehicle quick-charging socket is connected with the charging control unit through a low-voltage interface of the vehicle-mounted quick-slow charging integrated charging device; the energy input end of the vehicle slow charging socket is connected with the slow charging pile; the energy output end of the vehicle slow charging socket is connected with the energy input end of the AC/DC conversion module in series through the alternating current input interface of the vehicle-mounted fast and slow charging integrated charging device; the signal end of the vehicle slow charging socket is connected with the charging control unit through a low-voltage interface of the vehicle-mounted fast and slow charging integrated charging device; the control end of the charging control unit is respectively connected with the signal end of the AC/DC conversion module, the signal end of the DC/DC voltage reduction module and the signal end of the DC/DC voltage boosting module; the energy output end of the storage battery is respectively connected with the charging control unit and the energy input end of the DC/DC boosting module; the energy output end of the DC/DC boosting module is connected with a quick charging pile through a third switch, a direct-current input interface of the vehicle-mounted quick-slow charging integrated charging device and a vehicle quick-charging socket; the energy output end of the AC/DC conversion module is connected with the energy input end of the DC/DC voltage reduction module through a first switch; the energy output end of the DC/DC voltage reduction module is connected with the energy input end of the power battery through the direct current output interface of the vehicle-mounted fast and slow charging integrated charging device;

s2: when the electric automobile is connected to a charging pile for charging, a charging control unit of the vehicle-mounted quick and slow charging integrated device identifies which type of charging pile the vehicle is connected to through a signal input by a low-voltage interface, if the charging control unit identifies the charging pile, a quick charging working mode is started, and step S3 is executed; if the slow charging pile is identified, entering a slow charging working mode, and executing the step S4;

s3: in the quick charging working mode, the charging control unit performs signal interaction with a quick charging pile and a battery management unit of the power battery; the third switch is closed, the DC/DC boosting module converts the low-voltage direct current output by the storage battery into high-voltage direct current, and the high-voltage direct current is output to the quick charging pile through the vehicle quick charging socket; after detecting the high pressure of the vehicle end is built, the quick-charging pile starts to output; the third switch is switched off, and the DC/DC boost module is switched off; the second switch is closed, and the DC/DC voltage reduction module converts the high-voltage direct current output by the quick charging pile into low-voltage direct current and transmits the low-voltage direct current to the power battery;

s4: in a slow charging working mode, the charging control unit performs signal interaction with the slow charging pile and a battery management unit of the power battery; and when the first switch is closed, the AC/DC conversion module and the DC/DC voltage reduction module convert the alternating current output by the slow charging pile into low-voltage direct current and transmit the low-voltage direct current to the power battery.

Further, in step S3, in the fast charging mode, the specific steps of the charging control unit performing signal interaction with the fast charging pile and the battery management unit of the power battery are as follows:

s31: when the inserting and robbing detection circuit of the charging control unit detects a quick charging signal, the MCU control circuit and the DSP control circuit of the charging control unit are awakened;

s32: the MCU control circuit of the charging control unit receives the quick charging signal, enters a quick charging working mode and sends a signal comprising the quick charging working mode, an input voltage limit value and an input current limit value to the DSP control circuit of the charging control unit;

s33: and the DSP control circuit enters a fast charging working mode when receiving signals comprising a fast charging working mode, an input voltage limit value, an input current limit value, an output voltage and an output current, and respectively sends driving signals to the DC/DC boosting module and the DC/DC voltage reducing module.

Further, in step S4, in the slow charging mode, the specific steps of the charging control unit performing signal interaction with the slow charging pile and the battery management unit of the power battery are as follows:

s41: when the inserting and robbing detection circuit of the charging control unit detects a slow charging signal, the MCU control circuit and the DSP control circuit of the charging control unit are awakened;

s42: the MCU control circuit of the charging control unit receives a slow charging signal, enters a slow charging working mode, and sends signals comprising the slow charging working mode, an input voltage limit value and an input current limit value to the DSP control circuit of the charging control unit;

s43: and the DSP control circuit enters a slow charging working mode after receiving signals comprising a slow charging working mode, an input voltage limit value, an input current limit value, an output voltage and an output current, and respectively sends driving signals to the AC/DC conversion module and the DC/DC voltage reduction module.

The invention has the beneficial effects that:

1. according to the vehicle-mounted fast and slow charging integrated charging system and method for the low-voltage platform electric vehicle, aiming at the problem of charging convenience of the low-voltage platform electric vehicle at the present stage, a specific charging device and a control method are adopted, so that the function of charging the low-voltage platform electric vehicle in a conventional fast charging pile is realized, and the use convenience of the low-voltage platform electric vehicle is greatly improved.

2. According to the invention, the low-voltage platform electric vehicle is supported to use the slow charging pile to perform high-efficiency safe charging through the slow charging working mode, so that the charging compatibility of the low-voltage platform electric vehicle charging system is effectively improved.

Drawings

FIG. 1 is a functional block diagram of an embodiment of the present invention.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings and specific embodiments.

The low-voltage platform electric automobile is an electric automobile with a power battery voltage range smaller than 200V. As shown in fig. 1, an embodiment of the present invention includes: the vehicle slow charging socket, the vehicle fast charging socket, the vehicle-mounted fast and slow charging integrated charging device, a slow charging alternating current input loop formed by a high-voltage cable set 1, a fast charging direct current input loop formed by a high-voltage cable set 2, a direct current output loop formed by a high-voltage cable set 3, a slow charging signal transmission line formed by a low-voltage cable set 1, a fast charging signal transmission line formed by a low-voltage cable set 2, a CAN communication signal transmission line formed by a low-voltage cable set 3, a power line formed by a low-voltage cable set 4, a 12V storage battery and a power battery.

The vehicle slow charging socket is used for transmitting a slow charging signal to a vehicle-mounted fast and slow charging integrated charging device through a slow charging signal transmission line formed by a low-voltage cable set 1 and transmitting alternating current (220V) output by a slow charging pile to the vehicle-mounted fast and slow charging integrated charging device through a slow charging alternating current input loop formed by a high-voltage cable set 1 when the vehicle slow charging socket is connected with a slow charging pile, so that the vehicle-mounted fast and slow charging integrated charging device enters a slow charging working mode and controls input current based on the slow charging signal; under the GB/T18487 standard, the slow charging signals are CC and CP.

The vehicle quick-charging socket is used for transmitting a quick-charging signal to a vehicle-mounted quick-slow charging integrated charging device through a quick-charging signal transmission line formed by a low-voltage cable set 2 and transmitting a high-voltage direct current (voltage is more than 200V) output by a quick-charging pile to the vehicle-mounted quick-slow charging integrated charging device through a quick-charging direct current input loop formed by a high-voltage cable set 2 when the vehicle quick-charging socket is connected with a quick-charging pile, so that the vehicle-mounted quick-slow charging integrated charging device enters a quick-charging working mode based on the quick-charging signal and controls input voltage and current; under the GB/T18487 and GB/T27930 standards, the quick-charging signals are CC2, A +, and quick-charging CAN communication signals defined by the standards.

The vehicle-mounted fast and slow charging integrated charging device is used for receiving alternating current (220V) output by the slow charging pile through a slow charging alternating current input loop formed by the vehicle slow charging socket and the high-voltage cable set 1, converting the slow charging alternating current into direct current matched with the voltage of the power battery, and transmitting the direct current to the power battery through a direct current output loop formed by the high-voltage cable set 3; or the high-voltage direct current (voltage is more than 200V) output by the quick charging pile is received through a quick charging direct current input loop formed by the vehicle quick charging socket and the high-voltage cable set 2, the high-voltage direct current (voltage is more than 200V) is converted into low-voltage direct current (voltage is less than 200V), and the low-voltage direct current is transmitted to the power battery through a direct current output loop formed by the high-voltage cable set 3;

the vehicle-mounted quick and slow charging integrated charging device mainly comprises an alternating current input interface, a direct current input interface, an AC/DC conversion module, a DC/DC boosting module, a DC/DC voltage reducing module, a charging control unit, a K1/K2/K3 switch (normally open), a low-voltage interface and a direct current output interface.

The charging control unit is connected with the vehicle slow charging socket through a slow charging signal transmission line formed by the low-voltage interface and the low-voltage cable group 1, and is used for receiving the slow charging signal, entering a slow charging working mode based on the slow charging signal and controlling input current; or, a fast charging signal transmission line formed by the low-voltage interface and the low-voltage cable group 2 is connected with the vehicle fast charging socket, and is used for receiving the fast charging signal, entering a fast charging working mode based on the fast charging signal, and controlling input voltage and current; the charging control unit is connected with the battery management unit through a CAN communication signal transmission line formed by the low-voltage interface and the low-voltage cable group 3 while receiving a slow charging signal or a fast charging signal, and is used for receiving CAN signals of the power battery, such as allowable charging voltage, allowable charging current, SOC (system on chip) and the like, and controlling output voltage and current based on the CAN signals of the power battery; the power line formed by the low-voltage interface and the low-voltage cable group 4 is connected with a 12V storage battery and used for supplying power to the charging control unit;

specifically, the charge control unit mainly includes: insert and rob detection circuitry, MCU control circuit and DSP control circuit, wherein, insert and rob detection circuitry for detect fill signal or fill the signal soon slowly, work as and detect fill signal or fill the signal soon slowly, insert and rob detection circuitry and pass through internal power chip output 5V voltage and awaken up MCU control circuit and DSP control circuit.

The MCU control circuit is used for receiving the slow charging signal after being awakened by the plugged robbing detection circuit, entering a slow charging working mode based on the slow charging signal, controlling the K1 switch to be closed, and controlling the K2/K3 switch to be opened, and sending working mode (slow charging), input voltage and input current limit signals to the DSP control circuit; or, the voltage regulator is used for receiving the fast charge signal, entering a fast charge working mode based on the fast charge signal, controlling a K2/K3 switch to be closed and a K1 switch to be opened, and sending working mode (fast charge), input voltage and input current limit signals to the DSP control circuit; the power battery charging control circuit is used for receiving CAN signals of the power battery, such as allowable charging voltage, allowable charging current, SOC (system on chip) and the like, and sending output voltage and output current signals to the DSP control circuit based on the CAN signals of the power battery while receiving slow charging signals or fast charging signals.

The DSP control circuit is used for receiving the working mode signal, the input voltage, the input current limit signal, the output voltage signal and the output current signal after being awakened by the plugged robbing detection circuit; based on a working mode (slow charge) signal, an input voltage and input current limit signal, and an output voltage and output current signal, entering a slow charge working mode, and sending a driving signal to an AC/DC module and a DCDC voltage reduction module to enable the AC/DC module and the DCDC voltage reduction module to start working to convert alternating current output by a slow charge pile into direct current and output the direct current to a power battery; or, based on the working mode (fast charge) signal, the input voltage, the input current limit signal, and the output voltage and output current signal, entering the fast charge working mode, sending a driving signal to the DC/DC voltage boost module and the DCDC voltage reduction module, so that the DC/DC voltage boost module and the DCDC voltage reduction module start to work, convert the high-voltage direct current (voltage >200V) output by the fast charge pile into low-voltage direct current (voltage <200V), and output the low-voltage direct current to the power battery.

The AC/DC conversion module is connected with a vehicle slow charging socket through a slow charging AC input loop formed by the AC input interface and the high-voltage cable set 1 and used for receiving the AC output by the slow charging pile, and the AC/DC conversion module works based on a driving signal sent by the DSP control module, converts the 220V AC output by the slow charging pile into DC and transmits the DC to the DC/DC voltage reduction module. The AC/DC conversion module mainly comprises a filter circuit and a bridgeless PFC circuit; the filter circuit is used for effectively filtering ripples in alternating current input by the slow charging pile; the bridgeless PFC circuit is used for receiving a driving signal sent by the DSP control circuit, turning on or off the MOSFET based on the driving signal, converting alternating current processed by the filter circuit into direct current and finishing power factor correction.

The DC/DC boosting module is connected with the 12V storage battery through a power line consisting of a low-voltage interface and a low-voltage cable set 4 and is used for receiving 12V direct current output by the storage battery; a quick charging direct current input loop formed by a K3 switch, a direct current input interface and a high-voltage cable group 2 is connected with a vehicle quick charging socket and used for outputting high-voltage direct current (voltage is more than 200V) to a quick charging pile and simulating the voltage of the vehicle end required to be detected when the quick charging pile is started. The DC/DC boosting module works based on a driving signal sent by the DSP control circuit, converts 12V direct current output by the storage battery into high-voltage direct current (voltage is more than 200V) and transmits the high-voltage direct current to the quick-charging pile, and simulates the end voltage of a vehicle which needs to be detected when the quick-charging pile is started. The DC/DC boost module mainly comprises: an inverter circuit and a rectifier circuit; the inverter circuit is used for receiving a driving signal sent by the DSP control circuit, turning on or turning off the MOSFET based on the driving signal, converting 12V low-voltage power of the storage battery into alternating current through the inverter circuit and outputting the alternating current to the rectifying circuit; the rectification circuit is used for converting alternating current output by the inverter circuit into high-voltage direct current (voltage is greater than 200V) and transmitting the high-voltage direct current to the quick-charging pile, and the voltage of the vehicle end required to be detected when the quick-charging pile is started is simulated.

The DC/DC voltage reduction module is connected with a vehicle quick charging socket through a quick charging direct current input loop formed by a K2 switch, a direct current input interface and a high-voltage cable set 2 and is used for receiving high-voltage direct current (the voltage is more than 200V) output by a quick charging pile; or the K1 switch is connected with the AC/DC module and used for receiving the direct current output by the AC/DC module; when receiving the high-voltage direct current (voltage >200V) output by the quick-charging pile or the direct current output by the AC/DC module, the direct current output loop formed by the direct current output interface and the high-voltage cable set 3 is connected with the power battery and used for outputting low-voltage direct current (voltage <200V) to the power battery. The DC/DC voltage reduction module works based on a driving signal sent by the DSP control circuit, and converts high-voltage direct current (voltage is greater than 200V) output by the quick charging pile or direct current output by the AC/DC module into low-voltage direct current (voltage is less than 200V) and transmits the low-voltage direct current to the power battery. The DC/DC voltage reduction module mainly comprises an inverter circuit and a rectification circuit; the inverter circuit is used for receiving a driving signal sent by the DSP control circuit, turning on or turning off the MOSFET based on the driving signal, and converting high-voltage direct current (voltage is greater than 200V) output by the quick charging pile or direct current output by the AC/DC module into alternating current to be output to the rectifying circuit; the rectifying circuit is used for receiving a driving signal sent by the DSP control circuit, turning on or turning off the MOSFET based on the driving signal, and converting the alternating current output by the inverter circuit into low-voltage direct current (the voltage is less than 200V) to be transmitted to the power battery.

Example two: the vehicle-mounted fast and slow charging integrated device is replaced by a split scheme, and an AC/DC conversion module is integrated with a DC/DC voltage reduction module to realize a slow charging function; and the DC/DC boosting module and the DC/DC voltage reducing module are integrated into a whole to realize the quick charging function.

Example three: and a 12V storage battery for supplying power to the primary side of the DC/DC boosting module is replaced by a quick charging pile A + for supplying power.

According to the vehicle-mounted fast and slow charging integrated charging system for the low-voltage platform electric vehicle, the problem that the low-voltage platform electric vehicle cannot be charged by using the universal fast charging pile is solved through the fast charging working mode, and the slow charging pile is used for charging through the slow charging working mode, so that the compatibility and the charging convenience of the low-voltage platform electric vehicle charging system are greatly improved.

The working method of the vehicle-mounted fast and slow charging integrated charging system of the low-voltage platform electric vehicle comprises the following steps:

when electric automobile inserts and fills electric pile and charge, the signal identification vehicle that fills the integral type device by on-vehicle speed fills through the low pressure interface input charge for which of electric pile that the control unit that charges, when the discernment is for filling a little the access, get into and fill the mode slowly, when the discernment is for filling a little the access, get into and fill the mode soon.

In a slow charging working mode, the charging control unit performs signal interaction with the slow charging pile and the battery management unit, the charging control unit controls the K1 switch to be closed, the AC/DC conversion module and the DC/DC voltage reduction module are started, slow charging pile alternating current (-220V) received by a vehicle slow charging socket, a slow charging alternating current input loop formed by the high-voltage cable set 1 and an alternating current input interface is converted into low-voltage direct current (voltage <200V), and the low-voltage direct current is transmitted to the power battery through a direct current output loop formed by the direct current output interface and the high-voltage cable set 3.

In a quick charging working mode, the charging control unit performs signal interaction with the quick charging pile and the battery management unit, the charging control unit controls the K3 switch to be closed, the DC/DC boosting module is started, 12V low-voltage power input by a power line formed by the low-voltage interface and the low-voltage cable set 4 is converted into high-voltage direct current (voltage is more than 200V), and the high-voltage direct current is output to the quick charging pile through a quick charging direct current input loop formed by the K3 switch, the direct current input interface and the high-voltage cable set 2 and a vehicle quick charging socket; after the quick charging pile detects that high voltage (voltage is more than 200V) at a vehicle end is established, starting output is started, after the quick charging pile is started and output, the charging control unit controls the K2 switch to be closed again, the DC/DC voltage reduction module is started, then the K3 switch is controlled to be opened, the DC/DC voltage boosting module is closed, high-voltage direct current (voltage is more than 200V) of the quick charging pile received by a quick charging direct current input loop and a direct current input interface which are formed by a vehicle quick charging socket and a high-voltage cable set 2 is converted into low-voltage direct current (voltage is less than 200V), and the low-voltage direct current is transmitted to the power battery through a direct current output loop formed by a direct current output interface and a high-voltage cable set 3.

The signal interaction of the vehicle-mounted fast and slow charging integrated charging system of the low-voltage platform electric vehicle comprises the following steps: in a slow charging mode, signal interaction between the vehicle-mounted fast and slow charging integrated device and the slow charging pile and signal interaction between the vehicle-mounted fast and slow charging integrated device and the battery management unit; and in the quick charging mode, the vehicle-mounted quick and slow charging integrated device is in signal interaction with the quick charging pile and in signal interaction with the battery management unit.

The signal interaction between the vehicle-mounted fast and slow charging integrated device and the slow charging pile is executed according to GB/T18487, and the content comprises the following steps: CC. And (6) CP.

The signal interaction between all vehicle-mounted fast and slow charging integrated devices and the fast charging pile is executed according to GB/T18487 and GB/T27930, and the contents comprise: CC1, CC2, A +, and CAN signals defined by the Standard

The signal interaction content between the vehicle-mounted fast and slow charging integrated device and the battery management unit comprises the following steps: the battery management unit sends the charging allowable voltage, the charging allowable current, the SOC and the like of the power battery to the vehicle-mounted fast and slow charging integrated device, and the vehicle-mounted fast and slow charging integrated device sends the charging mode, the charging gun connection state, the device working state, the input voltage and current, the output voltage and current to the power battery.

The above embodiments are only used for illustrating the design idea and features of the present invention, and the purpose of the present invention is to enable those skilled in the art to understand the content of the present invention and implement the present invention accordingly, and the protection scope of the present invention is not limited to the above embodiments. Therefore, all equivalent changes and modifications made in accordance with the principles and concepts disclosed herein are intended to be included within the scope of the present invention.

Claims (10)

1. The utility model provides an on-vehicle fast and slow integral type charging system that fills of low voltage platform electric motor car which characterized in that:

the vehicle-mounted fast-slow charging integrated charging device comprises a vehicle fast-charging socket, a vehicle slow-charging socket, a vehicle-mounted fast-slow charging integrated charging device, a power battery and a storage battery; the vehicle-mounted quick and slow charging integrated charging device comprises a charging control unit, a DC/DC boosting module, an AC/DC conversion module, a DC/DC voltage reduction module, a first switch, a second switch and a third switch;

the energy input end of the vehicle quick charging socket is connected with the quick charging pile; the energy output end of the vehicle fast charging socket is sequentially connected with the energy input end of the second switch and the energy input end of the DC/DC voltage reduction module in series through the direct current input interface of the vehicle-mounted fast and slow charging integrated charging device; the signal end of the vehicle quick-charging socket is connected with the charging control unit through a low-voltage interface of the vehicle-mounted quick-slow charging integrated charging device; the vehicle quick-charging socket is used for sending a quick-charging signal to the charging control unit when the quick-charging pile is communicated, and transmitting high-voltage direct current output by the quick-charging pile to the DC/DC voltage reduction module, so that the vehicle-mounted quick-slow charging integrated charging device enters a quick-charging working mode and controls input voltage and current;

the energy input end of the vehicle slow charging socket is connected with the slow charging pile; the energy output end of the vehicle slow charging socket is connected with the energy input end of the AC/DC conversion module in series through the alternating current input interface of the vehicle-mounted fast and slow charging integrated charging device; the signal end of the vehicle slow charging socket is connected with the charging control unit through a low-voltage interface of the vehicle-mounted fast and slow charging integrated charging device; the vehicle slow charging socket is used for sending a slow charging signal to the charging control unit when the slow charging pile is communicated, and transmitting alternating current output by the slow charging pile to the AC/DC conversion module, so that the vehicle-mounted fast and slow charging integrated charging device enters a slow charging working mode and controls input current;

the control end of the charging control unit is respectively connected with the signal end of the AC/DC conversion module, the signal end of the DC/DC voltage reduction module and the signal end of the DC/DC voltage boosting module and is used for respectively sending driving signals to the AC/DC conversion module, the DC/DC voltage reduction module and the DC/DC voltage boosting module;

the energy output end of the storage battery is respectively connected with the energy input ends of the charging control unit and the DC/DC boosting module and is respectively used for supplying power to the charging control unit and the DC/DC boosting module;

the energy output end of the DC/DC boosting module is connected with a quick charging pile through a third switch, a direct-current input interface of the vehicle-mounted quick-slow charging integrated charging device and a vehicle quick-charging socket; the DC/DC boosting module is used for converting low-voltage direct current output by the storage battery into high-voltage direct current according to a driving signal of the charging control unit and transmitting the high-voltage direct current to the quick charging pile so as to simulate the voltage of the vehicle end required to be detected when the quick charging pile is started;

the energy output end of the AC/DC conversion module is connected with the energy input end of the DC/DC voltage reduction module through a first switch; the AC/DC conversion module is used for converting the alternating current output by the slow charging pile into direct current according to a driving signal of the charging control unit and transmitting the direct current to the DC/DC voltage reduction module;

the energy output end of the DC/DC voltage reduction module is connected with the energy input end of the power battery through the direct current output interface of the vehicle-mounted fast and slow charging integrated charging device; the DC/DC voltage reduction module is used for converting the high-voltage direct current output by the quick charging pile or the direct current output by the AC/DC module into low-voltage direct current matched with the requirement of the power battery according to the driving signal of the charging control unit and transmitting the low-voltage direct current to the power battery.

2. The vehicle-mounted fast and slow charging integrated charging system of the low-voltage platform electric vehicle as claimed in claim 1, characterized in that: the power battery comprises a battery management unit; the signal end of the battery management unit is connected with the charging control unit through a low-voltage interface of the vehicle-mounted quick and slow charging integrated charging device; the battery management unit is used for sending signals including the charging permission voltage, the charging permission current and the SOC of the power battery to the charging control unit so as to control the voltage and the current output by the vehicle-mounted quick-slow charging integrated charging device.

3. The vehicle-mounted fast and slow charging integrated charging system of the low-voltage platform electric vehicle as claimed in claim 2, characterized in that: the charging control unit comprises a plugging detection circuit, an MCU control circuit and a DSP control circuit; the inserting and robbing detection circuit is used for detecting a slow charging signal or a fast charging signal and outputting a high level signal to wake up the MCU control circuit and the DSP control circuit when the slow charging signal or the fast charging signal is detected;

the MCU control circuit is used for receiving a fast charge signal or a slow charge signal, receiving signals including an allowable charge voltage, an allowable charge current and an SOC of the power battery after being awakened by the plugged robbing detection circuit, and sending signals including a fast charge working mode or a slow charge working mode, an input voltage limit value and an input current limit value to the DSP control circuit; the DSP control circuit is used for receiving signals including a fast charge working mode or a slow charge working mode, an input voltage limit value, an input current limit value, an output voltage and an output current after being awakened by the inserted robbing detection circuit, and respectively sending driving signals to the DC/DC boosting module, the AC/DC conversion module and the DC/DC voltage reduction module.

4. The vehicle-mounted fast and slow charging integrated charging system of the low-voltage platform electric vehicle as claimed in claim 3, characterized in that: the DC/DC boosting module comprises an inverter circuit and a rectifying circuit;

the inverter circuit is used for converting the low-voltage direct current output by the storage battery into alternating current according to the driving signal sent by the DSP control circuit and outputting the alternating current to the rectifying circuit;

the rectification circuit is used for converting alternating current output by the inverter circuit into high-voltage direct current and transmitting the high-voltage direct current to the quick-charging pile, and the voltage of the vehicle end required to be detected when the quick-charging pile is started is simulated.

5. The vehicle-mounted fast and slow charging integrated charging system of the low-voltage platform electric vehicle as claimed in claim 3, characterized in that: the AC/DC conversion module comprises a filter circuit and a bridgeless PFC circuit;

the filter circuit is used for filtering ripples in alternating current output by the slow charging pile;

the bridgeless PFC circuit is used for converting alternating current passing through the filter circuit into direct current according to a driving signal sent by the DSP control circuit, correcting power factors and outputting the direct current to the DC/DC voltage reduction module.

6. The vehicle-mounted fast and slow charging integrated charging system of the low-voltage platform electric vehicle as claimed in claim 3, characterized in that: the DC/DC voltage reduction module comprises an inverter circuit and a rectification circuit;

the inverter circuit is used for converting the high-voltage direct current output by the quick charging pile or the direct current output by the AC/DC module into alternating current according to a driving signal sent by the DSP control circuit and outputting the alternating current to the rectifying circuit;

the rectification circuit is used for converting alternating current output by the inverter circuit into low-voltage direct current according to a driving signal sent by the DSP control circuit and outputting the low-voltage direct current to the power battery.

7. The vehicle-mounted fast and slow charging integrated charging system of the low-voltage platform electric vehicle as claimed in claim 1, characterized in that: also comprises

The slow charging alternating current input loop is formed by the first high-voltage cable group and is used for connecting the vehicle slow charging socket and an alternating current input interface of the vehicle-mounted fast and slow charging integrated charging device;

the quick charging direct current input loop is formed by the second high-voltage cable group and is used for connecting a vehicle quick charging socket and a direct current input interface of the vehicle-mounted quick and slow charging integrated charging device;

the direct current output loop is formed by a third high-voltage cable group and is used for connecting a direct current output interface of the vehicle-mounted quick and slow charging integrated charging device and an energy input end of the power battery;

the slow charging signal transmission line is formed by the first low-voltage cable group and used for connecting a signal end of the vehicle slow charging socket with the charging control unit;

the quick-charging signal transmission line is formed by the second low-voltage cable group and used for connecting a signal end of the vehicle quick-charging socket with the charging control unit;

the third low-voltage cable group forms a CAN communication signal transmission line for connecting a battery management unit and a charging control unit of the power battery;

and the power line formed by the fourth low-voltage cable group is used for respectively connecting the energy output end of the storage battery with the energy input end of the charging control unit and the energy input end of the DC/DC boosting module.

8. The charging method of the vehicle-mounted fast and slow charging integrated charging system of the low-voltage platform electric vehicle based on any one of claims 1 to 7 is characterized in that: the method comprises the following steps:

s1: the method comprises the steps that a vehicle-mounted fast and slow charging integrated charging system of the low-voltage platform electric vehicle is built, and the vehicle-mounted fast and slow charging integrated charging system comprises a vehicle fast charging socket, a vehicle slow charging socket, a vehicle-mounted fast and slow charging integrated charging device, a power battery and a storage battery; the vehicle-mounted quick and slow charging integrated charging device comprises a charging control unit, a DC/DC boosting module, an AC/DC conversion module, a DC/DC voltage reduction module, a first switch, a second switch and a third switch; the energy input end of the vehicle quick charging socket is connected with the quick charging pile; the energy output end of the vehicle fast charging socket is sequentially connected with the energy input end of the second switch and the energy input end of the DC/DC voltage reduction module in series through the direct current input interface of the vehicle-mounted fast and slow charging integrated charging device; the signal end of the vehicle quick-charging socket is connected with the charging control unit through a low-voltage interface of the vehicle-mounted quick-slow charging integrated charging device; the energy input end of the vehicle slow charging socket is connected with the slow charging pile; the energy output end of the vehicle slow charging socket is connected with the energy input end of the AC/DC conversion module in series through the alternating current input interface of the vehicle-mounted fast and slow charging integrated charging device; the signal end of the vehicle slow charging socket is connected with the charging control unit through a low-voltage interface of the vehicle-mounted fast and slow charging integrated charging device; the control end of the charging control unit is respectively connected with the signal end of the AC/DC conversion module, the signal end of the DC/DC voltage reduction module and the signal end of the DC/DC voltage boosting module; the energy output end of the storage battery is respectively connected with the charging control unit and the energy input end of the DC/DC boosting module; the energy output end of the DC/DC boosting module is connected with a quick charging pile through a third switch, a direct-current input interface of the vehicle-mounted quick-slow charging integrated charging device and a vehicle quick-charging socket; the energy output end of the AC/DC conversion module is connected with the energy input end of the DC/DC voltage reduction module through a first switch; the energy output end of the DC/DC voltage reduction module is connected with the energy input end of the power battery through the direct current output interface of the vehicle-mounted fast and slow charging integrated charging device;

s2: when the electric automobile is connected to a charging pile for charging, a charging control unit of the vehicle-mounted quick and slow charging integrated device identifies which type of charging pile the vehicle is connected to through a signal input by a low-voltage interface, if the charging control unit identifies the charging pile, a quick charging working mode is started, and step S3 is executed; if the slow charging pile is identified, entering a slow charging working mode, and executing the step S4;

s3: in the quick charging working mode, the charging control unit performs signal interaction with a quick charging pile and a battery management unit of the power battery;

the third switch is closed, the DC/DC boosting module converts the low-voltage direct current output by the storage battery into high-voltage direct current, and the high-voltage direct current is output to the quick charging pile through the vehicle quick charging socket;

after detecting the high pressure of the vehicle end is built, the quick-charging pile starts to output;

the third switch is switched off, and the DC/DC boost module is switched off;

the second switch is closed, and the DC/DC voltage reduction module converts the high-voltage direct current output by the quick charging pile into low-voltage direct current and transmits the low-voltage direct current to the power battery;

s4: in a slow charging working mode, the charging control unit performs signal interaction with the slow charging pile and a battery management unit of the power battery;

and when the first switch is closed, the AC/DC conversion module and the DC/DC voltage reduction module convert the alternating current output by the slow charging pile into low-voltage direct current and transmit the low-voltage direct current to the power battery.

9. The charging method according to claim 8, characterized in that: in step S3, in the fast charging mode, the specific steps of the charging control unit performing signal interaction with the fast charging pile and the battery management unit of the power battery are as follows:

s31: when the inserting and robbing detection circuit of the charging control unit detects a quick charging signal, the MCU control circuit and the DSP control circuit of the charging control unit are awakened;

s32: the MCU control circuit of the charging control unit receives the quick charging signal, enters a quick charging working mode and sends a signal comprising the quick charging working mode, an input voltage limit value and an input current limit value to the DSP control circuit of the charging control unit;

s33: and the DSP control circuit enters a fast charging working mode when receiving signals comprising a fast charging working mode, an input voltage limit value, an input current limit value, an output voltage and an output current, and respectively sends driving signals to the DC/DC boosting module and the DC/DC voltage reducing module.

10. The charging method according to claim 8, characterized in that: in the step S4, in the slow charging mode, the specific steps of the charging control unit performing signal interaction with the slow charging pile and the battery management unit of the power battery are as follows:

s41: when the inserting and robbing detection circuit of the charging control unit detects a slow charging signal, the MCU control circuit and the DSP control circuit of the charging control unit are awakened;

s42: the MCU control circuit of the charging control unit receives a slow charging signal, enters a slow charging working mode, and sends signals comprising the slow charging working mode, an input voltage limit value and an input current limit value to the DSP control circuit of the charging control unit;

s43: and the DSP control circuit enters a slow charging working mode after receiving signals comprising a slow charging working mode, an input voltage limit value, an input current limit value, an output voltage and an output current, and respectively sends driving signals to the AC/DC conversion module and the DC/DC voltage reduction module.

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