CN114161983B - A battery swapping system for an electric vehicle and a charging method for a battery pack - Google Patents

Abstract

The application provides a charging method of electric motor car battery replacement system and battery package relates to energy-concerving and environment-protective, new energy automobile field, can be when judging that the electric quantity of electric motor car is not enough, is full of at least one battery package for the nearby storehouse that charges of electric motor car in advance, like this, when the electric motor car arrived the storehouse that charges, need not wait for the process that the battery package charges, has shortened the process that the electric motor car traded the battery.

Description

A battery swapping system for an electric vehicle and a charging method for a battery pack

technical field

The embodiments of the present application relate to the technical field of charging and swapping electric vehicles, and in particular, to a battery swapping system for electric vehicles and a charging method for a battery pack.

Background technique

The strategic significance of the development of electric vehicles to alleviate the pressure on the energy environment and cultivate new economic growth points has become increasingly prominent, so the electric vehicle industry has been more developed. Electric vehicles have significant advantages such as high efficiency, energy saving, low noise, and zero emission, and have irreplaceable advantages in terms of environmental protection and energy saving. However, the battery power of electric vehicles is limited, the charging time is long, and the battery life is poor, which restricts the development of electric vehicles.

In a possible design, a battery swapping station for electric vehicles is provided. When the battery power of the electric vehicle is low, the battery with insufficient power of the electric vehicle can be disassembled, and the electric vehicle is replaced with a fully charged battery at the changing station.

However, in this design, after the electric vehicle arrives at the swap station, there is no fully charged battery in the swap station, and the electric vehicle needs to wait for a fully charged battery to appear in the swap station before the battery can be replaced, resulting in a long waiting time for the electric vehicle .

Contents of the invention

The application provides an electric vehicle battery replacement system and a charging method for a battery pack, which are used to solve the problem of too long waiting time when the electric vehicle battery is replaced.

On the one hand, the present application provides an electric vehicle power exchange system, the electric vehicle power exchange system includes a management system, N energy storage converters PCS, and M battery packs; M is the product of a and N, and a is An integer greater than 1, N is an integer greater than 1, and any PCS includes a bidirectional DC-AC DC-AC charging module.

The PCS is connected to the bus through a transformer. Wherein, the busbar may be an AC busbar.

Any DC-AC charging module is connected to a parallel battery pack in the M battery packs, and a switching device is connected between any battery pack in a parallel battery pack and any DC-AC charging module. It is used to select the battery pack connected to the DC-AC charging module according to the control of the management system.

The management system is used to obtain the battery power of the electric vehicle from a server. The server is a cloud server for real-time interaction with the electric vehicle, and the real-time battery power of the electric vehicle is stored in the server.

The management system is also used to connect the target battery pack to the target DC-AC charging module through the switch device and control the target DC-AC charging module when the battery power is lower than the first power value and the M battery packs are not fully charged. The AC charging module quickly charges the target battery pack with the maximum power that the target battery pack can withstand; wherein, the target battery pack is the battery pack with the most power in the M battery packs, or the target battery pack is the M battery packs with power greater than A battery pack with a second power level that supports fast charging.

Optionally, the management system is specifically configured to connect the target battery pack to the target DC-AC charging module through the switch device when the battery power is lower than the first power value and the M battery packs are not fully charged, and The target DC-AC charging module will be disconnected from the other a-1 battery packs, and the target DC-AC charging module will be controlled to quickly charge the target battery with the maximum power that the target battery can withstand.

Optionally, the management system is also specifically configured to control any battery pack in the M battery packs except the target battery pack to quickly charge the target battery pack when the target DC-AC charging module is disconnected from the bus.

Optionally, any one of the battery packs includes multiple battery cells; the management system is also used to provide any The DC-AC charging module configures the first power so that any DC-AC charging module charges a parallel battery packs with the first power, wherein the first power is equal to the electric quantity of the respective battery cells in the a parallel battery packs related.

Optionally, a switch is provided between the busbar and the grid, and the management system is also used to control the busbar to disconnect the grid through the switch when the electric energy of the busbar is lower than the threshold value, and to control some or all of the battery packs in the M battery packs to pass through The corresponding DC-AC charging module charges the bus to supply power for loads connected to the bus.

Optionally, the management system includes: PCS control unit, BMS unit, whole station control unit, power replacement control unit, video monitoring unit, fire control system control unit and local monitoring unit;

Among them, the PCS control unit is used to control the PCS to realize charging and discharging of the battery pack; the BMS unit is used to manage the state of the battery pack; the whole station control unit is used for the overall management of the power station; Monitoring; the fire control system control unit is used to control the fire protection equipment in the substation; the local monitoring unit is used to monitor the local status of the equipment.

On the other hand, the embodiment of the present application also provides a battery pack charging method, which is applied to the above-mentioned electric vehicle battery replacement system, and the method includes:

The battery power of the electric vehicle is obtained from the server, which is a cloud server for real-time interaction with the electric vehicle, and the real-time battery power of the electric vehicle is stored in the server.

When the battery power is lower than the first power value, and the M battery packs are not fully charged battery packs, the target battery pack is connected to the target DC-AC charging module through the switch device, and the target DC-AC charging module is controlled to use the target battery The maximum power that the battery pack can withstand is used to quickly charge the target battery pack; wherein, the target battery pack is the battery pack with the most power in the M battery packs, or the target battery pack is the M battery packs with power greater than the second power value and supports Fast charging battery pack.

Optionally, connect the target battery pack to the target DC-AC charging module through the switch device, and control the target DC-AC charging module to quickly charge the target battery pack with the maximum power that the target battery pack can withstand, including: through the switch device Connect the target battery pack to the target DC-AC charging module, and disconnect the target DC-AC charging module from the other a-1 battery packs, and control the target DC-AC charging module to use the maximum power that the target battery can withstand Fast charge the target battery.

Optionally, it also includes: when the target DC-AC charging module is disconnected from the bus, controlling any battery pack in the M battery packs except the target battery pack to quickly charge the target battery pack.

Optionally, any battery pack includes a plurality of battery cells; the method also includes: when the battery power is greater than the first power value, and/or, when there are fully charged battery packs in M battery packs, for any DC- The AC charging module configures the first power so that any one of the DC-AC charging modules charges a parallel battery packs with the first power, wherein the first power is related to the power of each battery unit in the a parallel battery packs.

The embodiment of the present application provided by this application provides an electric vehicle battery exchange system and a battery pack charging method, which can fill at least one battery pack in the charging compartment near the electric vehicle in advance when it is judged that the electric vehicle is insufficient. , When the electric vehicle arrives at the charging compartment, there is no need to wait for the charging process of the battery pack, which shortens the process of changing the battery of the electric vehicle.

Description of drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the application and together with the description serve to explain the principles of the application.

FIG. 1 is a scene diagram of a power station replacement in a mining area according to an embodiment of the present application;

FIG. 2 is a schematic diagram of an electric vehicle battery replacement system according to an embodiment of the present application;

Fig. 3 is a schematic diagram of a specific battery exchange system for an electric vehicle according to an embodiment of the present application.

By means of the above drawings, specific embodiments of the present application have been shown, which will be described in more detail hereinafter. These drawings and text descriptions are not intended to limit the scope of the concept of the application in any way, but to illustrate the concept of the application for those skilled in the art by referring to specific embodiments.

Detailed ways

Reference will now be made in detail to the exemplary embodiments, examples of which are illustrated in the accompanying drawings. When the following description refers to the accompanying drawings, the same numerals in different drawings refer to the same or similar elements unless otherwise indicated. The implementations described in the following exemplary embodiments do not represent all implementations consistent with this application. Rather, they are merely examples of apparatuses and methods consistent with aspects of the present application as recited in the appended claims.

First, the nouns involved in this application are explained:

Electric vehicle: A vehicle powered by electricity, for example electric vehicles can include electric cars, electric motorcycles, electric trucks, etc.

Power storage converter (power control system, PCS): controls the charging and discharging process of the battery, performs AC-DC conversion, and can directly supply power to AC loads in the absence of a grid.

Battery state of charge (state of charge, SOC): refers to the state of charge of the battery, that is, the ratio of the remaining charge capacity in the battery to the capacity of the fully charged state, usually expressed as a percentage. SOC=1 means the battery is fully charged.

Battery state of health (state of health, SOH): refers to the battery capacity, health, and performance status, that is, the percentage of the full charge capacity of the battery relative to the rated capacity. The new battery is 100%, and the completely scrapped battery is 0%.

Battery management system (battery management system, BMS): It is a system that manages batteries, and usually has the function of measuring battery voltage to prevent or avoid abnormal conditions such as battery over-discharge, over-charge, and over-temperature.

The battery exchange of electric vehicles can be applied in various scenarios, such as electric vehicle battery exchange systems deployed on expressways or ordinary roads, or point-to-point multi-vehicle battery exchange systems deployed in residential areas.

In this embodiment of the present application, an electric vehicle battery exchange system (or called a battery exchange station) in a mining area is taken as an example to illustrate an application scenario of electric vehicle battery exchange. As shown in FIG. 1 , a power exchange station 100 in a mining area is provided. The power exchange station 100 includes the following areas: a management system 101 , a power exchange area 102 , a vehicle passage area 103 , a pressure transformation cabin 104 , and a station power area 105 .

The management system 101 realizes the management of one or more of the following: whole station control, charging control, battery replacement control, fire control system control, video monitoring and/or on-site monitoring.

The whole station control is used to control the operation of the whole power station. The whole station control communicates and interacts with one or more units of charging control, battery replacement control, fire control system control, video surveillance and on-site monitoring, and performs energy scheduling and energy optimization according to the summarized information, so as to make the operation of the whole station safe reliable. Charging control is used to control the charging and discharging process of the battery according to the current remaining battery capacity. Battery swap control is used to control battery peripherals such as battery swap robots and swap connectors. The fire control system is used to suppress and extinguish the fire by controlling the fire protection system when a sudden fire occurs in the power station, so that the power station can operate safely. Video monitoring is used for comprehensive video monitoring of all systems in the substation. On-site monitoring is used for real-time online charging monitoring, battery replacement monitoring, vehicle monitoring, power distribution monitoring and environmental monitoring.

The battery replacement area 102 is used to provide a replacement platform for the vehicle battery. The battery replacement area includes the battery replacement platform, charging compartment and battery replacement mechanism. The battery exchange platform is used to provide a docking and battery exchange operation area for the battery exchange vehicle; the charging compartment is used to charge the battery; the battery exchange mechanism includes a battery exchange robot and a battery exchange connector, etc. Put in the battery.

The vehicle passage area 103 is an area where vehicles can pass.

The voltage transformation cabin 104 is provided with a power distribution room and a power distribution cabinet, which are used to convert the high-voltage power of the power grid into the voltage required by each equipment in the substation. The voltage of each equipment includes one or more of the following: the voltage required by the power exchange system, the working voltage of related controllers, the daily power consumption voltage of the station, etc.

The power consumption area 105 of the station is an area for replacing daily electrical appliances such as air conditioners, lamps and/or power supplies installed in the station.

At the current swap station, when the electric vehicle arrives at the swap station, it enters the swap area and stops at the swap platform. The battery replacement control system controls the battery replacement robot to remove the battery with insufficient power of the electric vehicle, take out the fully charged battery from the charging compartment and install it on the electric vehicle, and put the replaced battery with insufficient power into the charging compartment. The battery replacement system charges the battery with insufficient power. After the battery swap process is over, the electric vehicle drives out of the swap station and continues on. However, when there is no fully charged battery in the swapping station, the electric vehicle needs to wait for a fully charged battery to appear in the swapping station after arriving at the swapping station before the battery can be changed, resulting in an excessively long waiting time for the electric vehicle.

Based on this, the embodiment of the present application provides an electric vehicle battery replacement system and a battery pack charging method, which can fill at least one battery pack in the charging compartment near the electric vehicle in advance when it is judged that the electric vehicle is insufficient. In this way, When the electric vehicle arrives at the charging compartment, there is no need to wait for the charging process of the battery pack, which shortens the process of changing the battery of the electric vehicle.

The technical solution of the present application will be described in detail below with specific embodiments. The following specific embodiments may be combined with each other, and the same or similar concepts or processes may not be repeated in some embodiments. Embodiments of the present application will be described below in conjunction with the accompanying drawings.

As shown in FIG. 2 , a battery swapping system for an electric vehicle according to this embodiment.

The electric vehicle power exchange system of the embodiment of the present application includes a management system 210, N energy storage converters PCS220, any PCS includes a bidirectional DC-AC DC-AC charging module 230, and M battery packs 241; M is a and The product of N, a is an integer greater than 1, and N is an integer greater than 1.

One end of the PCS is connected to the AC bus through the transformer 260, and the other end is connected to the battery pack. PCS is used for bidirectional conversion of electric energy. Specifically, the DC-AC charging module of PCS can rectify the alternating current of the bus bar into direct current. The PCS can also invert the DC power of the battery pack into AC power through the DC-AC charging module and transmit it to the bus. The number of PCS is N, and N is an integer greater than 1.

The DC-AC charging module of PCS is electrically connected with a parallel battery pack. A switching device 242 is provided between any battery pack and the DC-AC charging module connected to it. The DC-AC charging module is used to select the connected battery pack and charge the battery pack by opening and closing the switching device according to the power allocated by the PCS according to the control of the management system. The number of DC-AC charging modules is N, and N is an integer greater than 1.

Wherein, the battery pack may be obtained by connecting multiple battery units in series, or may be a single battery unit, which is not limited in this embodiment of the present application.

The management system is used to obtain the battery power of the electric vehicle from the server 250, which is a cloud server for real-time interaction with the electric vehicle, and the real-time battery power of the electric vehicle is stored in the server.

Exemplarily, the cloud server may refer to a server that provides services for the vehicle, and when the electric vehicle travels to an area served by the cloud server, the cloud server may acquire the battery power of the electric vehicle.

In the embodiment of the present application, the method for obtaining real-time battery power of an operating electric vehicle based on a cloud server may include the following methods:

Method 1: The management system periodically sends a request command to the cloud server, requesting to obtain the real-time battery power of the electric vehicle. Based on the request command sent by the management system, the cloud server sends the real-time battery power of the electric vehicle to the management system.

Method 2: The cloud server periodically and proactively sends the real-time battery power of the electric vehicle to the management system.

The management system is also used to connect the target battery pack to the target DC-AC charging module through the switch device when the battery power is lower than the first power value, and the M battery packs are not fully charged, and control the PCS to pass through the target battery pack. The DC-AC charging module quickly charges the target battery pack with the maximum power that the target battery pack can withstand; wherein, the target battery pack is the battery pack with the most power in the M battery packs, or the target battery pack is M battery packs A battery pack with a power greater than the second power value and supporting fast charging.

Among them, the management system can be divided into a local management system and a remote management system. The local management system is responsible for the control, monitoring and protection of the battery alarm and PCS of the local swap station, and the remote is responsible for coordinating the work of the vehicle and the swap station.

In the embodiment of the present application, if the battery power is lower than the first power value, it means that the electric vehicle needs to be charged or the battery needs to be replaced, and the M battery packs are not fully charged, which means that the electric vehicle battery replacement system cannot provide timely support for the electric vehicle. Provide a fully charged battery. If you do not get a fully charged battery in time, you may need to wait for the electric car. Wherein, the first power value may be a preset value, such as any value of 0-20%, and the embodiment of the present application does not specifically limit the first power value.

Therefore, when the battery power of the electric vehicle is lower than the first power value, and the M battery packs are not fully charged, the management system can connect the target battery pack to the target DC-AC charging module through the switch device, and control the target The DC-AC charging module quickly charges the target battery pack with the maximum power that the target battery pack can withstand, so that the power station can prepare a fully charged battery pack for the electric vehicle as soon as possible, reducing the time for the electric vehicle to wait for the battery pack to charge.

Among them, the target battery pack can be the battery pack with the most power among the M battery packs. In this way, the battery pack with the most power can be quickly charged to a fully charged battery pack, reducing the time for the electric vehicle to wait for the battery pack to be charged, so that the vehicle can reach the battery replacement station , it is more likely to get a fully charged battery pack directly.

Alternatively, the target battery packs may be M battery packs with power greater than the second power value and supporting fast charging. The fast charging may refer to supporting the fast charging referred to in the fast charging protocol. In this way, the battery pack that supports fast charging and has sufficient power can be quickly charged to a fully charged battery pack, reducing the time for electric vehicles to wait for the battery pack to be charged, so that when the vehicle arrives at the replacement station, it is more likely to get a fully charged battery pack directly.

It should be noted that in Fig. 2, the management system can realize wired or wireless communication with PCS, switch devices, servers, etc., which is not shown in the figure, and the embodiment of the present application does not specifically limit the communication mode between devices that need to communicate.

Optionally, on the basis of FIG. 2 , the management system of the embodiment of the present application is specifically used to find M battery packs when the battery power is lower than the first power value and the M battery packs are not fully charged. The battery pack with the most power in the battery pack, or the battery pack with the power greater than the second power value among the M battery packs, connects the battery pack and the corresponding DC-AC charging module through a switch device, and disconnects the other a-1 batteries The connection between the package and the corresponding DC-AC charging module.

Exemplarily, the management system may control the output power of the PCS corresponding to the battery pack, and rapidly charge the battery with the maximum power that the target battery pack can bear through the DC-AC charging module. And in the embodiment of the present application, the other outer a-1 battery packs are disconnected from the corresponding DC-AC charging module, so that the DC-AC charging module can only charge the target battery pack, further improving the charging efficiency of the target battery pack , so that the target battery pack can be further quickly charged to a fully charged battery pack, shortening the charging time of the target battery pack.

Optionally, on the basis of FIG. 2, the management system of the embodiment of the present application is also specifically used to find out the battery pack with the most power in the M battery packs, or the power in the M battery packs is greater than the second power value. battery pack, but the target DC-AC charging module corresponding to the battery pack is disconnected from the bus and cannot be charged. Control any battery pack except the target battery pack among the M battery packs to quickly charge the target battery pack. Through this step, in the grid segment network mode, the fast charging of the battery pack that is close to full charge or the battery pack with a relatively large amount of power remaining in the swap station can be realized, which saves battery charging time.

Optionally, on the basis of FIG. 2 , any battery pack includes multiple battery cells. The management system of the embodiment of the present application is also used to configure the first power for any DC-AC charging module when the power in the M battery packs is greater than the first power value, and/or when there is a fully charged battery pack, Make any one of the DC-AC charging modules charge a parallel battery packs with the first power, wherein the first power is related to the electric quantity of each battery unit in the a parallel battery packs.

Exemplarily, the management system can collect the maximum rechargeable current of each battery pack in real time through EtherCAT, and the management system controls the PCS to configure a more suitable first power for the DC-AC charging modules, so that each DC-AC charging module passes through the appropriate power. The battery packs connected in parallel are charged, and the suitable first power is related to the electric quantity of each battery unit in the battery packs connected in parallel. In this way, when the electric vehicle does not need to be charged urgently or the power station has a fully charged battery, the appropriate power can be used to charge the battery pack, reducing the impact of fast charging on the life of the battery pack and improving the performance of the battery pack.

Optionally, the way to calculate the first power can be:

First, the system obtains the optimum operating power of the battery pack by checking the value according to the battery voltage and the battery data sheet, which is denoted as sopcL.

Calculate the total power of the current battery pack in real time:

Among them, the power of each cluster of battery clusters (or battery cells) is bmspower[n].

Find the proportion of each cluster of battery clusters:

bmspowerscale[n]=bmspower[n]/power

Find the maximum charging and discharging power supported by each cluster of batteries:

power_bms[n]=sopcL/bmspowerscale[n]

Get the first power that actually satisfies the demand:

SOPC=MIN(power_bms[1], power_bms[2],...,power)bms[n])

The system operates according to SOPC, so that each cluster does not exceed the maximum charge and discharge capacity of the battery until the battery capacity is consistent and the allocated power is consistent.

Wherein, the power unit mentioned above may be kw.

Optionally, on the basis of Fig. 2, the management system is also used to control some or all of the M battery packs to charge the bus through the corresponding DC-AC charging module when the electric energy of the bus is lower than the threshold. In this way, when the electric energy of the grid is lower than the threshold, the battery pack of the swap station charges the busbar through the DC-AC module, and feeds the electric energy back to the grid, realizing peak regulation and frequency modulation of the grid, alleviating the pressure on the grid, and maintaining the stability of the grid.

Wherein, the DC-AC charging module may also be called a bidirectional DC-AC charging module, and the bidirectional DC-AC charging module is connected with the energy storage converter. After receiving the charging instruction of the energy storage battery, the bidirectional DC-AC electric module receives the power of the power station from the energy storage converter, and charges the battery through the power of the power station; after receiving the command of discharging the energy storage battery, the bidirectional DC-AC electric module passes The energy storage converter discharges to the grid.

Optionally, on the basis of Figure 2, the management system can also flexibly control the charging of the PCS according to the temperature of the battery pack, the SOC of the battery pack, the temperature of the battery of the electric vehicle, and the SOC of the battery of the electric vehicle.

Optionally, on the basis of Figure 2, the management system includes: a PCS control unit, a BMS unit, a whole station control unit, a power replacement control unit, a video monitoring unit, a fire control system control unit, and an on-site monitoring unit. The specific content will be described in subsequent embodiments, and will not be repeated here.

In order to more clearly illustrate the battery swapping system for electric vehicles in the embodiment of the present application, FIG. 3 shows a schematic diagram of a specific swapping station.

As shown in Figure 3, the power exchange station can include a power distribution room, and multiple transformers can be installed in the power distribution room. Multiple transformers can change the voltage of the bus to different voltage values for charging the battery pack, or for power supply in the power exchange station. power supply for the device.

For example, the busbar can be a 35KV busbar, the transformer used to charge the battery pack can be a 3MVA step-up transformer, and the one used to power the equipment in the swap station can be a 500KVA station transformer. In possible implementations, the 500KVA station transformer can be further passed The low-voltage power distribution cabinet gets 380V voltage to supply power for the equipment in the swap station.

Among them, the equipment in the swap station can be referred to as a load, for example, including: a swap mechanism (also called a swap system), an air conditioner, a light, a power supply, a ground charging switch, an uninterruptible power supply (Uninterruptible Power Supply, UPS), etc.

The UPS can supply power to the management system. The management system includes, for example: PCS control unit, BMS unit, whole station control unit, power replacement control unit, video monitoring unit, fire control system control unit and on-site monitoring unit.

The PCS control unit is used to control the PCS to realize efficient and fast charging and discharging of the battery pack. The BMS unit can be used to manage the state of the battery pack, such as monitoring the SOC or SOH of the battery pack. The whole station control unit can be used for the overall management of the power station. The video monitoring unit can be used for video monitoring in the substation. The fire control system control unit can be used for the control of fire protection equipment in the substation. The local monitoring unit can be used to realize the local monitoring of the monitoring equipment.

It is understandable that there can be multiple power exchange locations in the power exchange station, so multiple branches can be drawn from the 3MVA step-up transformer to multiple power exchange locations. Any power exchange location includes the electric vehicle battery exchange system, and the electric vehicle exchange system The electrical system may include a PCS, a battery system, and the like. The battery system may include multiple battery packs, a BMS corresponding to each battery pack, a switching device corresponding to each battery pack, a switching power supply, etc. The switching power supply may be used to supply power to the switching devices, etc., and multiple battery packs are connected in parallel. Multiple battery packs are connected in parallel, which can realize automatic power balance between battery packs, and can flexibly select the number of rechargeable battery packs on the parallel side, which is convenient for system access, and can shorten the charging time by reducing the number of rechargeable battery packs.

The power exchange station can be understood from three levels from large to small, for example, the first level: the power exchange station, including the electric vehicle power exchange system for realizing power exchange, and the electrical equipment in the power exchange station. The second layer: In the electric vehicle battery replacement system involving battery replacement, it includes PCS, battery packs, and related connectors. Among them, when assisting the electric vehicle battery exchange system on the second floor to realize the automatic battery exchange of electric vehicles, the third layer can also be included: the battery exchange mechanism, including the battery exchange robot, the battery exchange connector, etc., through which the electric vehicle can be realized as an electric vehicle. The car automatically changes the battery pack, saving manpower.

In a possible implementation, the electric vehicle power exchange system includes a power distribution room, a power distribution cabinet, a plurality of energy storage converters, an energy storage unit, a switching power supply, a management system, and a load.

The power distribution room is electrically connected to multiple PCSs and power distribution cabinets respectively. The power distribution room provides 380V power input for PCS and power distribution cabinets. The power distribution cabinet provides the power input of the appropriate voltage for the load. Loads include air conditioners, lights, etc.

PCS is used for two-way conversion of electric energy and controls the charging and discharging process of the battery. Specifically, the PCS rectifies the alternating current of the power grid into direct current and provides it to charge the battery pack. The PCS inverts the DC power of the battery pack into AC power, sends it to the grid, and discharges the battery. Moreover, PCS supports charging power setting, charging and discharging mode setting, etc., and the control method is more flexible.

The energy storage unit may include a DC-AC charging module and a battery pack. A DC-AC charging module is connected to a battery pack. There are multiple battery packs under each battery pack, and the multiple battery packs are connected in parallel. A switching device is connected between any one of the battery packs connected in parallel and the corresponding DC-AC charging module, and the switching device is used to select the battery pack connected to the DC-AC charging module according to the control of the management system.

The switching power supply is electrically connected to the BMS, and the switching power supply can be used to provide a 24V working voltage for the BMS unit. The BMS unit is used to monitor the remaining power SOC and the state of health SOH of the battery pack, and feed back the battery condition to the management system. Further, the management system can determine whether there is a battery pack that needs battery health maintenance according to the SOH of the battery pack, and if there is a battery that needs battery health maintenance, it will discharge the battery pack that needs battery health maintenance.

The battery replacement system is used to realize the charging process of the battery pack. Specifically, the PCS converts the external input AC power into the required DC power, and charges the battery pack through the DC-AC charging module.

The management system is powered by an uninterruptible power supply UPS, which is electrically connected to the power distribution cabinet. The UPS obtains power from the power distribution cabinet and converts it into 220V voltage for output to the management system.

The management system obtains the remaining battery power of the operating electric vehicle from the cloud server, and the remaining battery power is monitored by the on-board BMS unit and uploaded to the cloud server. The management system determines whether there is an electric vehicle that needs to be replaced urgently. If it detects that the battery of the electric vehicle is low, it will notify the electric vehicle to drive to the nearby battery replacement station to replace the battery.

The battery swap system also includes a battery swap mechanism. The battery replacement mechanism may include a battery replacement robot and a battery replacement connector. The battery replacement mechanism is used to take out the battery or put it into the charging compartment. Specifically, when the electric vehicle is parked on the battery exchange platform, the battery exchange robot removes the battery with insufficient power from the electric vehicle, takes out the fully charged battery from the charging compartment and installs it on the electric vehicle, and replaces the battery with insufficient power. Put the battery into the charging compartment.

The management system controls how the PCS unit charges the battery pack, and there are three possible implementations.

In the first possible implementation, the management system detects through the BMS unit that all the batteries in the current charging compartment are below 90% and there are no fully charged battery packs, and collects the battery packs according to the BMS unit. Find the battery pack with the most power in all battery packs, or the battery pack with more than 60% power in all battery packs, connect the battery pack with the corresponding DC-AC charging module through the switch device, and disconnect the remaining battery packs from the corresponding DC-AC charging module. AC charging module. According to the maximum input power of the battery pack collected by the BMS unit, the management system controls the PCS to quickly charge it with the maximum power that the battery pack can withstand through the DC-AC charging module.

In the second possible implementation, when the management system detects through the BMS unit that all batteries in the current charging compartment are below 90% and there are no fully charged battery packs, the BMS unit collects the power status of all battery packs. Find the battery pack with the most charge among all the battery packs, or the battery pack with more than 60% charge among all the battery packs. If the battery pack is disconnected from the bus bar and cannot be charged, the battery pack is connected to the corresponding DC-AC charging module through a switch device, and any other battery pack other than the battery pack is controlled to quickly charge the battery pack.

In the third possible implementation, the management system detects through the BMS unit that there are more than 90% battery packs in all the batteries in the current charging compartment, or when there are fully charged battery packs, configure the DC-AC charging modules separately. The more appropriate power enables each DC-AC charging module to charge the parallel battery packs with appropriate power, and the appropriate power is related to the electric quantity of each battery unit in the parallel battery packs. Any one battery pack includes a plurality of battery cells.

In order to make full use of resources, the management system controls the direction of power transmission in the power exchange system according to the health status of the battery and the power of the grid.

For example, when the management system detects that there are many fully charged battery packs through the BMS unit, the number of battery packs that need to be charged is small, and the power of the bus is lower than the threshold, the management system controls the direction of PCS power transmission, and some or all of the battery packs Charge the bus through the DC-AC charging module.

In a possible implementation, the management system of the swap station obtains the remaining battery power of the operating electric vehicle from the cloud server, and the remaining battery power is monitored by the on-board BMS unit and uploaded to the cloud server. The management system determines whether there is a vehicle that needs to be replaced urgently. If it is detected that there is a vehicle that needs to be replaced urgently, the BMS unit will monitor whether there is a fully charged battery in the charging compartment of the replacement station. When there is no fully charged battery, the management system notifies the PCS control unit to set the charging power and charging mode of the PCS, so that the target battery pack can be fully charged quickly under the premise of safety. If it is detected that the current running vehicle does not urgently need to be replaced, the target battery pack is charged with a more suitable power.

The whole station control is used to control the operation of the whole power station. The whole station control communicates and interacts with the PCS control unit, BMS unit, power exchange control unit, video monitoring unit, fire control system control unit and on-site monitoring unit, and performs energy scheduling and energy utilization optimization according to the summary information, so that the whole station The operation is safe and reliable.

Battery swap control is used to control battery peripherals such as battery swap robots and battery swap connectors.

The fire control system is used to suppress and extinguish the fire by controlling the fire protection system when a sudden fire occurs in the swap station, so that the swap station can operate safely.

Video monitoring is used to realize comprehensive video monitoring of all systems in the swap station.

On-site monitoring is used for real-time online charging monitoring, battery replacement monitoring, vehicle monitoring, power distribution monitoring and environmental monitoring.

To sum up, the embodiment of this application uses energy storage PCS to replace the traditional charging pile, realizes the function of charging and discharging the battery, improves the system efficiency by 5%, reduces the cost of the charging module by more than 50%, and the charging power can be more flexible The receiving station control system (or called the management system) is controlled by the management system. The management system can flexibly control the charging of the PCS according to the current battery cell, temperature, SOC and the SOC of the currently operating vehicle. The management system can use the information sent from the cloud to detect When there is a vehicle that needs to be replaced urgently and there is no fully charged battery in the current position, the battery pack with more power can be controlled to quickly charge it with the maximum power that the battery can withstand. More suitable power for charging. Flexible charging methods are also beneficial to parameters such as battery life, safety, and cruising range.

The communication in the power station can adopt the EtherCAT distributed slave station architecture. Due to the large area of the power station, the master control needs to collect a lot of information, the wiring is difficult, and once there is a communication problem with the operating device, the maintenance is more complicated, so the distributed structure is adopted. Arrange each slave station module in the power exchange area, vehicle passage area, pressure transformation cabin area, etc., and arrange the master control in the monitoring cabin. Through the EterCAT industrial real-time Ethernet communication method, the slave station module can access the local digital signal, The analog signal and 485 signal greatly shorten the length of the wiring harness and ensure the quality of communication. Moreover, EtherCAT has strong expandability, which is conducive to the later expansion of the station and the development of new functions.

The EtherCAT technology can be used to detect the battery information in the station in real time and can link the DC circuit breaker and medium voltage switchgear to act in time to prevent the spread of accidents when major problems occur.

Using fast battery parallel connection technology, the number of rechargeable batteries can be flexibly selected on the parallel side, and maintenance charging and discharging can be performed through PCS. The system is conveniently connected and the charging time is shortened.

Since the design of the battery pack needs to meet the requirements of power, voltage, and current at the same time, the battery pack is usually connected in multiple groups in parallel. Due to the operation of the vehicle, the discharge between the multiple packs is inconsistent, and the completion of pre-charging after charging leads to inconsistent current distribution between the battery packs. Therefore, The inconsistency of the current between the clusters may cause the PCS output power to be distributed unevenly to each battery pack. The traditional charging pile will cause a larger battery pack to be distributed with a larger current during high-power charging, resulting in charging overcurrent, which cannot guarantee that each battery pack Charging with optimal power, the embodiment of this application can collect the maximum rechargeable current of each battery pack in real time through EtherCAT, and control the PCS to ensure that the PCS runs at an optimal power, realize fast charging, and improve the safety and life of the battery pack.

It can be connected to the power grid system to adjust the peak and frequency of the power grid when the substation is idle, relieve the pressure on the power grid and create better economic value.

The management system can realize off-grid. Due to the instability of the power grid near the mine, when an unplanned power outage caused by an external accident occurs, it will cause a sudden power failure in the station. There is a risk of battery falling. PCS supports the off-grid function. When the 6KV suddenly loses power, the system will disconnect the 6KV upper switch of the medium voltage cabinet. Power supply with the battery replacement robot to ensure the normal progress of the current battery replacement of the vehicle.

In addition, the embodiment of the present application also provides a battery pack charging method, which is applied to the above-mentioned electric vehicle battery replacement system, and the method includes:

The battery power of the electric vehicle is obtained from the server, which is a cloud server for real-time interaction with the electric vehicle, and the real-time battery power of the electric vehicle is stored in the server.

When the battery power is lower than the first power value, and the M battery packs are not fully charged battery packs, the target battery pack is connected to the target DC-AC charging module through the switch device, and the target DC-AC charging module is controlled to use the target battery The maximum power that the battery pack can withstand is used to quickly charge the target battery pack; wherein, the target battery pack is the battery pack with the most power in the M battery packs, or the target battery pack is the M battery packs with power greater than the second power value and supports Fast charging battery pack.

Optionally, connect the target battery pack to the target DC-AC charging module through the switch device, and control the target DC-AC charging module to quickly charge the target battery pack with the maximum power that the target battery pack can withstand, including: through the switch device Connect the target battery pack to the target DC-AC charging module, and disconnect the target DC-AC charging module from the other a-1 battery packs, and control the target DC-AC charging module to use the maximum power that the target battery can withstand Fast charge the target battery.

Optionally, it also includes: when the target DC-AC charging module is disconnected from the bus, controlling any battery pack in the M battery packs except the target battery pack to quickly charge the target battery pack.

Optionally, any battery pack includes a plurality of battery cells; the method also includes: when the battery power is greater than the first power value, and/or, when there are fully charged battery packs in M battery packs, for any DC- The AC charging module configures the first power so that any one of the DC-AC charging modules charges a parallel battery packs with the first power, wherein the first power is related to the power of each battery unit in the a parallel battery packs.

Other embodiments of the present application will be readily apparent to those skilled in the art from consideration of the specification and practice of the approaches disclosed herein. This application is intended to cover any modification, use or adaptation of the application, these modifications, uses or adaptations follow the general principles of the application and include common knowledge or conventional technical means in the technical field not disclosed in the application . The specification and examples are to be considered exemplary only, with a true scope and spirit of the application indicated by the following claims.

It should be understood that the present application is not limited to the precise constructions which have been described above and shown in the accompanying drawings, and various modifications and changes may be made without departing from the scope thereof. The scope of the application is limited only by the appended claims.

Claims (10)

1. An electric vehicle power exchange system, characterized in that the electric vehicle power exchange system includes a management system, N energy storage converters PCS, and M battery packs; the M is the product of a and N, The a is an integer greater than 1, the N is an integer greater than 1, and any one of the PCS includes a bidirectional DC-AC DC-AC charging module; The PCS is connected to the bus through a transformer; Any of the DC-AC charging modules is connected to a parallel battery pack in the M battery packs, and any battery pack in the a parallel battery packs is connected to any one of the DC-AC charging modules. A switching device is connected, and the switching device is used to select a battery pack connected to the DC-AC charging module according to the control of the management system; The management system is used to obtain the battery power of the electric vehicle from a server, the server is a cloud server that interacts with the electric vehicle in real time, and the real-time battery power of the electric vehicle is stored in the server; The management system is further configured to connect the target battery pack to the target DC-AC through the switching device when the battery power is lower than the first power value and the M battery packs are not fully charged. A charging module, and controlling the target DC-AC charging module to quickly charge the target battery pack with the maximum power that the target battery pack can bear; wherein, the target battery pack is one of the M battery packs The battery pack with the most power, or, the target battery pack is a battery pack whose power of the M battery packs is greater than the second power value and supports fast charging. 2. The battery exchange system for electric vehicles according to claim 1, wherein the management system is specifically configured to be used when the battery power is lower than the first power value and the M battery packs are not fully charged. In the case of a battery pack, the target battery pack will be connected to the target DC-AC charging module through the switching device, and the target DC-AC charging module will be disconnected from the other a-1 battery packs, and the target battery pack will be controlled. The DC-AC charging module quickly charges the target battery with the maximum power that the target battery can bear. 3. The battery exchange system for electric vehicles according to claim 1 or 2, wherein the management system is further configured to control the charging system when the target DC-AC charging module is disconnected from the bus Any battery pack other than the target battery pack among the M battery packs realizes fast charging of the target battery pack. 4. The electric vehicle power exchange system according to claim 1 or 2, wherein any one of the battery packs includes a plurality of battery cells; The management system is further configured to charge any one of the DC-AC charging modules when the battery power is greater than the first power value, and/or there are fully charged battery packs in the M battery packs The first power is configured so that any one of the DC-AC charging modules charges the a parallel-connected battery packs with the first power, wherein the first power is the same as that of each of the a parallel-connected battery packs related to the power of the battery unit. 5. The electric vehicle power exchange system according to claim 1 or 2, characterized in that a switch is provided between the busbar and the power grid; The management system is further configured to control the bus to disconnect the power grid through the switch when the electric energy of the bus is lower than a threshold, and control some or all of the M battery packs to pass through the corresponding DC - an AC charging module for charging said bus to power loads connected to said bus. 6. The electric vehicle battery exchange system according to claim 1 or 2, characterized in that the management system includes: PCS control unit, BMS unit, whole station control unit, battery exchange control unit, video monitoring unit, fire protection system Control unit and local monitoring unit; Wherein, the PCS control unit is used to control the PCS to realize charging and discharging of the battery pack; the BMS unit is used to manage the state of the battery pack; the whole station control unit is used for overall management of the battery swap station; the The video monitoring unit is used for video monitoring in the switching station; the fire control system control unit is used for controlling the fire fighting equipment in the switching station; the local monitoring unit is used for monitoring the local conditions of the equipment. 7. A charging method for a battery pack, characterized in that it is applied to the electric vehicle battery replacement system according to any one of claims 1-6, said method comprising: Obtaining the battery power of the electric vehicle from a server, the server is a cloud server that interacts with the electric vehicle in real time, and the real-time battery power of the electric vehicle is stored in the server; When the battery power is lower than the first power value, and the M battery packs are not fully charged, connect the target battery pack to the target DC-AC charging module through a switch device, and control the target DC-AC charging The module rapidly charges the target battery pack with the maximum power that the target battery pack can bear; wherein, the target battery pack is the battery pack with the most power among the M battery packs, or the target battery pack The battery pack is a battery pack with the power of the M battery packs greater than the second power value and supporting fast charging. 8. The method according to claim 7, wherein the target battery pack is connected to the target DC-AC charging module through a switching device, and the target DC-AC charging module is controlled to use the target battery pack to The target battery pack is quickly charged with the maximum power it can withstand, including: Connect the target battery pack to the target DC-AC charging module through the switching device, and disconnect the target DC-AC charging module from the other a-1 battery packs, and control the target DC-AC charging module Fast charging is performed on the target battery with the maximum power that the target battery can bear. 9. The method according to claim 7 or 8, further comprising: When the target DC-AC charging module is disconnected from the bus bar, control any battery pack in the M battery packs except the target battery pack to fast charge the target battery pack. 10. The method according to claim 7 or 8, wherein any one of the battery packs includes a plurality of battery cells; the method further comprises: When the battery power is greater than the first power value, and/or there are fully charged battery packs in the M battery packs, configure the first power for any one of the DC-AC charging modules, so that the Any one of the DC-AC charging modules charges the a parallel-connected battery packs with the first power, wherein the first power is related to the electric quantity of each battery unit in the a parallel-connected battery packs.