CN209955776U

CN209955776U - Battery charging device

Info

Publication number: CN209955776U
Application number: CN201920301426.9U
Authority: CN
Inventors: 冯韬; 褚福来; 孟保国
Original assignee: Beijing Dongfang Yangtai New Energy Technology Co Ltd
Current assignee: Beijing Dongfang Yangtai New Energy Technology Co Ltd
Priority date: 2019-03-08
Filing date: 2019-03-08
Publication date: 2020-01-17
Anticipated expiration: 2029-03-08

Abstract

The application discloses a battery charging device, which comprises a charging seat, an output cable, a main controller, a battery analog DC-DC converter and at least one charging DC-DC converter; the main controller is suitable for carrying out BMS protocol handshake communication with the charging pile and informing the battery to simulate the DC-DC converter to start after the communication is successful; the battery analog DC-DC converter is suitable for performing boost conversion on the voltage of a BMS power supply to obtain an analog voltage and outputting the analog voltage to the charging seat, wherein the analog voltage is within the legal voltage range of the charging pile; the main controller is also suitable for sending the charging required voltage and the charging required current to the charging pile and informing the at least one charging DC-DC converter to start working in response to the detected output voltage of the charging pile; the charging DC-DC converter is suitable for converting the output voltage of the charging pile into a battery charging voltage so as to charge the battery through the output cable. The utility model discloses make the standard rifle that charges can be used to the charging of low rated voltage battery.

Description

Battery charging device

Technical Field

The present application relates to the field of power supply or distribution circuit arrangements or systems, and in particular to battery charging arrangements.

Background

The capacity of the power lithium battery serving as a core component of the new energy vehicle is rapidly expanded day by day, the cost is reduced continuously, and the lead-acid battery is gradually replaced in part of application occasions, such as an electric moped, an old scooter, a low-speed vehicle and some special engineering construction vehicles, such as a forklift. However, the rated voltage of the lithium battery for the vehicle in these applications is generally below 200V, and the charging specifications of all the dc fast charging piles currently kept in the market are 500V and 750V, and most of the minimum operating voltages are 200V and 250V, respectively, and thus the lithium battery cannot be used by the vehicle. In addition, the direct current that present part has been built fills electric pile also becomes idle stake owing to geographical position, user are few etc. and cause the very big waste of resource.

SUMMERY OF THE UTILITY MODEL

An object of the present application is to provide a battery charging device that enables a standard high-voltage charging pile that is currently held to be available for charging of a low rated voltage battery.

In order to solve the above technical problem, according to a first aspect of the present invention, there is provided a battery charging apparatus, comprising a charging stand, an output cable, a main controller, a battery analog dc-dc converter, and at least one charging dc-dc converter; the main controller is suitable for responding to the acquired BMS (battery management system) power supply voltage, carrying out BMS protocol handshaking communication with the charging pile and informing the battery to simulate the direct-current converter to start working after the communication is successful; the battery analog DC-DC converter is suitable for performing boost conversion on the voltage of a BMS power supply to obtain an analog voltage and outputting the analog voltage to the charging seat, wherein the analog voltage is within the legal voltage range of the charging pile; the main controller is also suitable for sending a charging required voltage and a charging required current to the charging pile, wherein the charging required voltage is greater than the analog voltage, and the main controller informs at least one charging DC-DC converter to start working in response to the detection of the output voltage of the charging pile; the charging DC-DC converter is suitable for converting the charging pile output voltage obtained by the charging seat into battery charging voltage so as to charge the battery through the output cable.

As an improvement of the first aspect of the present invention, a clamping diode is connected between each of the battery analog dc-dc converter and the at least one charging dc-dc converter.

As another improvement of the first aspect of the present invention, the battery charging apparatus further includes a bleed circuit adapted to bleed the high voltage below the safe voltage when the main controller determines that charging is completed or abnormal.

As a further improvement of the first aspect of the invention, the battery charging apparatus further comprises a human-computer interaction unit adapted to transmit user input to the main controller and/or receive information from the main controller for display.

As a further improvement of the first aspect of the present invention, the battery charging apparatus further comprises a status display unit adapted to display a current status of the battery charging apparatus.

As a further development of the first aspect of the invention, the main controller is further adapted to, in response to reaching the end-of-charge condition, inform the at least one charging dc-dc converter and/or the battery simulating dc-dc converter to stop operating.

As a further improvement of the first aspect of the present invention, the main controller is further adapted, in response to detecting that the charging pile output voltage drops to a voltage close to the analog voltage, to 1) reduce the charging demand current until the charging pile output voltage continues to be maintained at the charging demand voltage; or 2) increasing the charging demand voltage to improve the output voltage of the charging pile; or 3) informing at least one charging DC-DC converter and/or battery analog DC-DC converter to stop working.

As a further improvement of the first aspect, the charging demand current is the maximum output capacity current value of the charging pile.

Through the utility model discloses the device will adopt the lower vehicle simulation of rated voltage to become a rated voltage and be greater than certain voltage like 300V's vehicle to make it can use the electric pile of filling of present 500V and 750V specification to charge, make present electric pile of filling can furthest come into use, create due value. Specifically, the utility model has the following advantages:

1) the charging system is suitable for connecting and charging vehicles of any low-rated voltage version with all direct-current charging piles, and can increase the utilization rate of the charging piles to form economic benefits for charging pile operators;

2) the utility model can form various rated power specifications, has different sizes and is convenient to be placed on different vehicles, thereby being convenient to use;

3) the utility model can fully utilize the idle charging pile in the society, and has strong social benefit;

4) the utility model discloses the main control unit of device is the simulation battery and the simulation stake of charging simultaneously during operation, and integral type design reliability is high, with low costs, is fit for extensive marketing;

5) the charging system has the function of a battery simulator, can be effectively identified as an effective battery by all charging piles, and can smoothly enter charging flow control;

6) the utility model discloses the main control unit in the device simulates for BMS (battery management system) unit sends battery information to the charging pile, if no BMS exists at the vehicle end, virtual and safe battery information is sent according to the national standard;

7) when the vehicle is in a circuit shortage state and cannot find a proper alternating current power supply, the utility model can utilize the existing direct current charging pile as an input power supply to carry out emergency charging;

8) the utility model is provided with a discharge circuit to ensure that the high voltage is discharged below the safe voltage when the charging is finished;

9) there is not BMS's application scene to the vehicle end, the utility model discloses can design a plurality of straight converters that charge in the device for one set of device can charge for more than one vehicle.

Drawings

Fig. 1 is a block diagram of an embodiment of a battery charging apparatus according to the present invention.

Fig. 2 is a schematic diagram of the operating principle of the two dc-dc converters shown in fig. 1.

Fig. 3 is a block diagram of the two dc-dc converters shown in fig. 1.

Fig. 4 is a flow chart of a method of operating a battery charging apparatus according to the present invention.

For the sake of clarity, the figures are schematic and simplified drawings, which only show details which are necessary for understanding the invention and other details are omitted.

Detailed Description

Embodiments and examples of the present invention will be described in detail below with reference to the accompanying drawings.

The scope of applicability of the present invention will become apparent from the detailed description given hereinafter. It should be understood, however, that the detailed description and the specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only.

Fig. 1 shows the structure of a preferred embodiment of the battery charging apparatus of the present invention. The battery charging device of the embodiment comprises a charging seat, an output cable, a power circuit, a main controller, a battery analog direct-current converter, a charging direct-current converter, a man-machine interaction unit and a discharge circuit. The charging seat adopts a charging seat interface of the latest national standard and is used for being connected with a charging gun of the direct current charging pile when the battery charging device works. The output cable is used for being connected with a direct current charging port at the vehicle end when the battery charging device works, meets the industrial standard or the national standard, is provided with a plug, and can be internally provided with a signal wire for connection confirmation besides a power cable. The input of the power supply circuit is provided by a charging gun BMS power supply on a charging pile, the power supply circuit supports the input of a 9-36V wide voltage range, the compatibility of the charging pile which provides 24V and 12V BMS power supply is ensured, the power supply circuit performs some processing such as filtering processing on the power supply provided by the BMS, the output of the power supply circuit is supplied to a main controller, a battery analog DC-DC converter, a possible vehicle terminal BMS and other elements such as a contactor, an indicator light and the like. In other embodiments, the operating voltage of the main controller, battery analog dc-dc converter, etc. may also be obtained directly from the BMS power supply. The main controller executes a vehicle terminal BMS simulation function aiming at the charging pile terminal, executes a charging pile simulation function aiming at the vehicle battery terminal, and controls start-stop and operation parameters of the two DC-DC converters. The main controller is suitable for responding to the acquired BMS power supply voltage, BMS protocol handshaking communication is carried out on the charging pile according to a national standard protocol, the battery simulation direct-current converter is informed to start work according to a corresponding national standard after communication is successful, and the charging pile controller can correctly enter a next step of interaction process after the charging pile can sample a legal voltage value. The two DC-DC converters are used for realizing the functions of a power unit for energy conversion and simulating the voltage of a battery, and can be in a transformer isolation type or a non-isolation type without a transformer. The battery simulation DC-DC converter works in a boosting mode, is suitable for boosting and converting the voltage of a BMS power supply so as to simulate the voltage of a battery and output the simulated voltage of the battery to a charging seat, and the simulated voltage of the battery is in the legal voltage range of the charging pile, so that the vehicle battery with low rated voltage can be identified by the charging pile. The simulated battery voltage is enabled to be in a legal voltage range of the charging pile, and the voltage detected by the charging pile is mainly in a charging output range (normal working range) of the charging pile. The legal voltage range is usually the rated voltage output range of the charging pile, and the legal voltage range can be 200-500V by combining two specifications of 500V and 750V of the charging pile in China at present, and an optimal value is selected by combining different product applications. The main controller is further suitable for sending the charging required voltage and the charging required current to the charging pile, wherein the charging required voltage is larger than the simulated battery voltage, and the charging required current can be the maximum output capacity current value of the charging pile. The main controller also informs the charging DC-DC converter to start up in response to the detection of the output voltage of the charging pile, the charging DC-DC converter works in a voltage reduction mode, the input voltage is the power output voltage of the charging pile, and the DC voltage output by the charging pile charging gun is reduced and output to the vehicle battery end, so that the charging function is realized. For some special vehicles, if the voltage is high at 500V, the charging dc-dc converter should be designed in buck-boost mode. During charging (during the operation of the charging DC-DC converter), the battery analog DC-DC converter can stop working or continue working. The discharge circuit is used for rapidly discharging unsafe high voltage at the input end and the output end in the device to be lower than safe voltage when the main controller determines that charging is finished or abnormal charging is finished. The man-machine interaction unit can be composed of a screen, keys and the like or is configured into a more advanced touch screen, the charging current of the low-voltage side can be set through manual setting, the situation is suitable for application scenes that a battery end does not have a BMS, the size of the charging current can be set according to the requirements of the user, and if the vehicle end also has the BMS, the charging is carried out according to the protocol of the BMS. In some application scenarios, such as no touch screen, the device may be configured functionally through an external communication interface or a dial switch, for example, to configure whether the vehicle has a BMS, a charging current, and the like. In other embodiments, the battery charging apparatus may further include a status display unit, such as an indicator lamp, a buzzer, or the like, adapted to display the current status of the battery charging apparatus. The specific components of the human-computer interaction unit and/or the state display unit can be reasonably added and deleted by combining with cost control.

In other embodiments, the battery charging device may not include a human-computer interaction unit, a status display unit, and/or a bleeding circuit.

In other embodiments, the battery charging apparatus may include more than two charging dc-dc converters, the connections and operational relationships between each of the more than two dc-dc converters and other components being the same as described in connection with fig. 1, to enable charging of more than two vehicle batteries simultaneously.

Fig. 2 shows the operating principle of the two dc-dc converters of fig. 1. V4 is the BMS supply voltage output by the charging post, which exists at both 12V and 24V for different charging posts. The voltage of a battery at the vehicle end is V2, the voltage V4 is boosted by the analog battery direct-current converter to obtain V1, the charging direct-current converter does not work, the charging required voltage sent to the charging pile by the main controller is V3, the required current is given according to the maximum output current of the charging pile, and V3 is more than V1 and more than V2 is more than V4. After the charging pile is started, the charging pile works in a constant voltage mode due to the fact that the charging DC-DC converter does not work, the constant voltage point is V3 at the moment due to the existence of the clamping diode, the analog battery DC-DC converter still outputs V1, and the port voltage of the device is increased to V3 from V1. The clamping diode is used for blocking the influence of the output voltage of the charging pile on the battery simulation direct-current/direct-current converter, and meanwhile, the clamping diode can stop working in the charging process so as to reduce the load of the charging pile BMS power supply. The main controller informs the charging DC-DC converter to start, the charging requirement is determined by the BMS setting of the vehicle end and the setting of the battery charging device, and the small value of the charging requirement and the setting of the battery charging device is taken as the current value of the charging requirement, if the vehicle is of a BMS-free type, the charging current is the set value of the controller. The method is characterized in that the charging pile mainly works in a constant voltage mode, if the charging demand of the vehicle end is overlarge, the charging pile enters a constant current mode, namely when the main controller detects that the voltage V3 is about to be smaller than V1, 3 processing algorithms can be adopted: 1) the charging device reduces the required current until the output voltage of the charging pile continues to maintain V3, and the method reduces the charging power and speed; 2) the charging device increases the charging required voltage to raise the output voltage of the charging pile to another reasonable voltage V5, and the scheme can keep the charging power and speed unchanged; 3) when the two schemes can not solve the problem, the controller in the device gives a charging stop instruction. The above 3 control methods require the controller in the device to perform optimal decision and execution in combination with the technical parameters of the charging dc-dc converter and the vehicle-end battery voltage. For example, the charging device has parameter configuration items built therein, and the user can select the method 1) or the method 2) as a preferred implementation scheme. The charging device may also be configured to adapt automatically, preferably according to method 2), and if it is found that the voltage V3 still cannot be guaranteed to be constant by increasing the charging requirement voltage to the maximum value, then the method 1) is started, the charging current on the charging side is reduced, and the charging power is reduced. The two DC-DC converters are independent of each other, are two sets of circuits, and work respectively to realize charging of the vehicle battery and simulation of a battery voltage which can be normally identified by the charging pile, so that the DC pile can charge the vehicle.

Fig. 3 shows a schematic structure of two dc-dc converters. The direct current input filter capacitor is used for filtering electromagnetic interference input from the outside and reducing the interference of the direct current input filter capacitor to the outside. And the bus capacitor C is used for stabilizing direct-current input voltage and ensuring the stability of the charging process. The power switch inverter circuit consists of a power MOS tube or an IGBT and a driving circuit matched with the power MOS tube or the IGBT and is used for switching on and off the input direct-current voltage at high frequency. The transformer adopts a high-frequency transformer scheme, and the square wave voltage on the primary side is boosted or reduced by the converter control chip, and if a non-isolation scheme is adopted, the transformer can be not adopted. The power rectification circuit rectifies the alternating-current square-wave voltage into direct-current voltage, and the voltage value is determined by the control chip. The output filter circuit is used for reducing and filtering circuit interference generated by the converter and reducing influence on an external circuit. The control chip starts or stops working according to an operation instruction given by a main control system of the device, the voltage which needs to be sampled and output when the control chip is started, the current value is calculated according to an algorithm, a level signal is sent to a driving circuit of the power switch inverter circuit, and finally the required output voltage value is obtained. To different applications, the DC-DC converter that charges can design for the step-down mode also can design for the mode of stepping up, perhaps possesses wide output range's design (compatible step-up and step-down), and the difference of this design mainly embodies at the manufacturing cost of device, does not influence the utility model discloses a realization and result. The utility model provides a direct-current converter is general design, and all can design the completion by technical personnel in the field, only has to differentiate on cost, reliability and realization principle topology, but above difference can not influence the utility model discloses a finally realize the usability of principle and device.

Fig. 4 illustrates a method of use and operation of the battery charging apparatus of the present invention. In step S10, the output cable of the charging device is connected to the vehicle. In step S11, the charging gun of the charging pile is inserted into the charging seat of the charging device. These two operations are not necessarily sequential. After the both ends of device are connected, in step S12, carry out the operation of charging on filling electric pile, fill electric pile and carry out the self-checking according to national standard agreement requirement, through the output BMS power supply of rifle that charges after the self-checking is unusual. In step S13, after the battery charging device obtains the BMS power supply, the main controller is awakened to start simulating the operation of the BMS, and starts BMS protocol handshaking communication with the charging pile according to the national standard protocol, after the handshaking succeeds, the main controller notifies the battery analog dc-dc converter to operate and output voltage, so that the charging pile controller can correctly enter the next step of interaction process after the charging pile can sample a legal voltage value, and can perform state display and exception handling (step S20). In step S14, according to the international protocol interaction process, the battery charging device sends a charging demand command to the charging pile, where the voltage value in the command is an appropriate value, but the voltage value must be greater than the output voltage of the battery analog dc-dc converter, and the current value may be the maximum output capability current value of the charging pile, and the charging pile has issued the current value to the main controller of the battery charging device according to the international protocol. At step S15, fill electric pile output voltage, fill electric pile work constant voltage mode this moment, this constant voltage point is sent out for filling electric pile through communication by main control unit. In the process of handshaking procedure of national standard protocol for charging between the battery charging device and the charging pile, if the BMS exists at the vehicle end, step S30 is also performed at the same time, and the main controller in the device and the vehicle BMS perform handshaking communication. In step S31, after the battery charging apparatus completes interaction with the vehicle BMS, a waiting state is entered. In step S16, the main controller detects the output voltage of the charging pile and then starts the charging dc-dc converter to operate, so as to charge the vehicle battery. In step S17, when the end condition is reached, the shutdown process is performed according to the national standard process, and the apparatus controller stops the operation of the two dc-dc converters. The end condition may be given by the vehicle terminal BMS, or by the battery charging device or by the charging post. In step S18, the charging pile performs shutdown processing. In step S19, the charging is completed, the vehicle returns to the original standby state, the output cable and the charging gun are pulled out, and the entire charging process is ended. If an abnormality occurs in the above steps, the process proceeds to an abnormality processing step S20, and the result of the abnormality is that charging cannot be performed or charging is stopped.

The various embodiments described herein, or certain features, structures, or characteristics thereof, may be combined as suitable in one or more embodiments of the invention.

As used herein, the singular forms "a", "an" and "the" include plural references (i.e., have the meaning "at least one"), unless the context clearly dictates otherwise. It will be further understood that the terms "has," "includes" and/or "including," when used in this specification, specify the presence of stated features, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, operations, elements, components, and/or groups thereof. The term "and/or" as used herein includes any and all combinations of one or more of the associated listed items.

Some preferred embodiments of the invention have been described in the foregoing, but it should be emphasized that the invention is not limited to these embodiments, but can be implemented in other ways within the scope of the inventive subject matter. The present invention can be modified and modified by those skilled in the art without departing from the scope of the present invention, and these modifications and modifications still fall into the protection scope of the present invention.

Claims

1. A battery charging device comprises a charging seat and an output cable, and is characterized by also comprising a main controller, a battery analog DC-DC converter and at least one charging DC-DC converter; the main controller is suitable for responding to the acquired BMS power supply voltage, performing BMS protocol handshake communication with the charging pile and informing the battery to simulate the DC-DC converter to start working after the communication is successful; the battery analog DC-DC converter is suitable for performing boost conversion on the voltage of a BMS power supply to obtain an analog voltage and outputting the analog voltage to the charging seat, wherein the analog voltage is within the legal voltage range of the charging pile; the main controller is also suitable for sending a charging required voltage and a charging required current to the charging pile, wherein the charging required voltage is greater than the analog voltage, and the main controller informs at least one charging DC-DC converter to start working in response to the detection of the output voltage of the charging pile; the charging DC-DC converter is suitable for converting the charging pile output voltage obtained by the charging seat into battery charging voltage so as to charge the battery through the output cable.

2. The battery charging apparatus of claim 1, wherein a clamping diode is connected between the battery analog dc-dc converter and each of the at least one charging dc-dc converter.

3. The battery charging apparatus of claim 1, further comprising a bleed circuit adapted to bleed the high voltage below a safe voltage when the main controller determines that charging is complete or abnormal.

4. The battery charging apparatus of claim 1, further comprising a human-machine interaction unit adapted to transmit user inputs to the master controller and/or receive information from the master controller for display.

5. The battery charging apparatus according to claim 1 or 4, further comprising a status display unit adapted to display a current status of the battery charging apparatus.

6. The battery charging apparatus of claim 1, wherein the master controller is further adapted to notify at least one of the charging dc-dc converter and/or the battery analog dc-dc converter to stop operating in response to reaching the end-of-charge condition.

7. The battery charging apparatus of claim 1, wherein the main controller is further adapted to, in response to detecting a drop in the charging post output voltage to near the analog voltage, 1) reduce the charging demand current until the charging post output voltage continues to be maintained at the charging demand voltage; or 2) increasing the charging demand voltage to improve the output voltage of the charging pile; or 3) informing at least one charging DC-DC converter and/or battery analog DC-DC converter to stop working.

8. The battery charging apparatus according to claim 1, wherein the charging demand current is a maximum output capacity current value of the charging pile.

9. The battery charging apparatus according to claim 5, wherein the status display unit is an indicator light, a buzzer, and/or a touch-sensitive display.