CN114161983A

CN114161983A - Battery replacing system of electric vehicle and charging method of battery pack

Info

Publication number: CN114161983A
Application number: CN202111364912.3A
Authority: CN
Inventors: 孙正晓; 刘骁; 杨振华; 张一鹏
Original assignee: Beijing Haibo Chuangyuan Technology Co ltd; Beijing Hyperstrong Technology Co Ltd
Current assignee: Beijing Haibosichuang Engineering Technology Co ltd; Beijing Hyperstrong Technology Co Ltd
Priority date: 2021-11-17
Filing date: 2021-11-17
Publication date: 2022-03-11
Anticipated expiration: 2041-11-17
Also published as: CN114161983B

Abstract

The application provides a charging method of an electric vehicle battery changing system and a battery pack, relates to the field of energy-saving, environment-friendly and new energy vehicles, and can fill at least one battery pack in a charging bin near the electric vehicle in advance when the electric quantity of the electric vehicle is judged to be insufficient, so that when the electric vehicle reaches the charging bin, the process of charging the battery pack is not required to be waited, and the process of changing the battery of the electric vehicle is shortened.

Description

Battery replacing system of electric vehicle and charging method of battery pack

Technical Field

The embodiment of the application relates to the technical field of electric vehicle charging and battery replacing, in particular to an electric vehicle battery replacing system and a battery pack charging method.

Background

The strategic significance of developing the electric vehicle for relieving the energy environmental pressure and cultivating new economic growth points is increasingly prominent, so that the electric vehicle industry is more developed. The electric vehicle has the remarkable advantages of high efficiency, energy conservation, low noise, zero emission and the like, and has irreplaceable advantages in the aspects of environmental protection and energy conservation. However, the development of the electric vehicle is restricted by the problems of limited electric quantity of the battery of the electric vehicle, longer charging time, poorer cruising ability and the like.

In a possible design, a battery replacing station for replacing batteries of electric vehicles is provided. When the electric quantity of the battery of the electric vehicle is insufficient, the battery with insufficient electric quantity of the electric vehicle can be detached, and the electric vehicle is replaced with the battery with full electric quantity in the battery replacing station.

However, in the design, after the electric vehicle arrives at the battery replacement station, the battery with the full electric quantity is not fully charged in the battery replacement station, and the electric vehicle can be replaced only when the battery with the full electric quantity is required to be charged in the battery replacement station, so that the waiting time of the electric vehicle is too long.

Disclosure of Invention

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

On one hand, the application provides an electric vehicle battery replacement system which comprises a management system, N energy storage converters (PCS) and M battery packs; m is the product of a and N, a is an integer greater than 1, N is an integer greater than 1, and any PCS includes a bidirectional direct current-alternating current DC-AC charging module.

The PCS is connected into the bus through a transformer. Wherein, the bus can be an alternating current bus.

Any one DC-AC charging module is connected with a battery pack in parallel connection in M battery packs, a switch device is connected between any one battery pack in a battery packs in parallel connection and any one DC-AC charging module, and the switch device is used for selecting the battery pack accessed to the DC-AC charging module according to the control of the management system.

The management system is used for acquiring the battery electric quantity of the electric vehicle from the server, the server is a cloud server which performs real-time interaction with the electric vehicle, and the real-time battery electric quantity of the electric vehicle is stored in the server.

The management system is also used for connecting the target battery pack with the target DC-AC charging module through the switching device and controlling the target DC-AC charging module to rapidly charge the target battery pack at the maximum power which can be borne by the target battery pack under the condition that the battery capacity is lower than the first electric quantity value and the M battery packs are not fully charged; the target battery pack is the battery pack with the largest electric quantity in the M battery packs, or the target battery pack is the battery pack with the electric quantity of the M battery packs larger than the second electric quantity value and supporting quick charging.

Optionally, the management system is specifically configured to, when the battery capacity is lower than the first capacity value and the M battery packs are not fully charged, connect the target battery pack to the target DC-AC charging module through the switching device, disconnect the target DC-AC charging module from the other a-1 battery packs, and control the target DC-AC charging module to rapidly charge the target battery with the maximum power that the target battery can bear.

Optionally, the management system is further specifically configured to control any battery pack, except the target battery pack, of the M battery packs to realize rapid charging of the target battery pack when the target DC-AC charging module is disconnected from the bus.

Optionally, any battery pack includes a plurality of battery units; and the management system is further used for configuring first power for any one DC-AC charging module when the battery capacity is larger than the first capacity value and/or when the M battery packs have fully charged battery packs, so that any one DC-AC charging module charges a battery packs connected in parallel through the first power, wherein the first power is related to the capacity of each battery unit in the a battery packs connected in parallel.

Optionally, a switch and a management system are arranged between the bus and the power grid, and 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 value, and control some or all of the M battery packs to charge the bus through the corresponding DC-AC charging module, so as to supply power to a load connected to the bus.

Optionally, the management system includes: the system comprises a PCS control unit, a BMS unit, a whole station control unit, a battery replacement control unit, a video monitoring unit, a fire fighting system control unit and an on-site monitoring unit;

the PCS control unit is used for controlling the PCS to charge and discharge the battery pack; the BMS unit is used for managing the state of the battery pack; the whole station control unit is used for managing the whole power change station; the video monitoring unit is used for monitoring videos in the power swapping station; the fire-fighting system control unit is used for controlling fire-fighting equipment in the power conversion station; the in-situ monitoring unit is used for monitoring the local condition of the equipment.

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

the method comprises the steps that the battery electric quantity of the electric vehicle is obtained from a server, the server is a cloud server which performs real-time interaction with the electric vehicle, and the real-time battery electric quantity of the electric vehicle is stored in the server.

Under the condition that the electric quantity of the battery is lower than a first electric quantity value and the M battery packs are not fully charged, connecting the target battery pack with a target DC-AC charging module through a switching device, and controlling the target DC-AC charging module to rapidly charge the target battery pack with the maximum power which can be borne by the target battery pack; the target battery pack is the battery pack with the largest electric quantity in the M battery packs, or the target battery pack is the battery pack with the electric quantity of the M battery packs larger than the second electric quantity value and supporting quick charging.

Optionally, the connecting the target battery pack to the target DC-AC charging module through the switching device, and controlling the target DC-AC charging module to rapidly charge the target battery pack with the maximum power that the target battery pack can bear includes: and connecting the target battery pack with the target DC-AC charging module through a switching device, disconnecting the target DC-AC charging module from the other a-1 battery packs, and controlling the target DC-AC charging module to rapidly charge the target battery at the maximum power which can be borne by the target battery.

Optionally, the method further includes: when the target DC-AC charging module is disconnected with the bus, any battery pack except the target battery pack in the M battery packs is controlled to realize the quick charging of the target battery pack.

Optionally, any battery pack includes a plurality of battery units; the method further comprises the following steps: and in the case that the battery capacity is larger than the first capacity value, and/or the M battery packs have fully charged battery packs, configuring the first power for any one DC-AC charging module, so that any one DC-AC charging module charges the a parallel battery packs through the first power, wherein the first power is related to the capacity of the battery unit in each of the a parallel battery packs.

The embodiment of the application provides an electric vehicle battery changing system and a battery pack charging method, and at least one battery pack can be fully filled in a charging bin near an electric vehicle in advance when the electric quantity of the electric vehicle is judged to be insufficient, so that when the electric vehicle reaches the charging bin, the process of waiting for the charging of the battery pack is not needed, and the process of changing the battery of the electric vehicle is shortened.

Drawings

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

Fig. 1 is a scene diagram of a power station swap 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 electric vehicle battery replacement system according to an embodiment of the application.

With the above figures, there are shown specific embodiments of the present application, which will be described in more detail below. These drawings and written description are not intended to limit the scope of the inventive concepts in any manner, but rather to illustrate the inventive concepts to those skilled in the art by reference to specific embodiments.

Detailed Description

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, like numbers in different drawings represent the same or similar elements unless otherwise indicated. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present application. Rather, they are merely examples of apparatus and methods consistent with certain aspects of the present application, as detailed in the appended claims.

The terms referred to in this application are explained first:

electric vehicle: vehicles powered using electric power, for example, electric vehicles may include electric automobiles, electric motorcycles, electric trucks, and the like.

Power Control System (PCS): the charging and discharging processes of the storage battery are controlled, alternating current and direct current conversion is carried out, and the alternating current load can be directly supplied with power under the condition of no power grid.

Battery state of charge (SOC): refers to the state of charge of the battery, i.e., the ratio of the remaining charge capacity in the battery to its fully charged capacity, expressed as a percentage. The SOC of 1 indicates a full battery state.

Battery state of health (SOH): the battery capacity, health degree and performance state are the storage battery capacity, health degree and performance state, namely the percentage of the full charge capacity of the storage battery to the rated capacity, the factory new battery is 100 percent, and the total scrap rate is 0 percent.

Battery Management System (BMS): the system is a system for managing a battery, and generally has a function of measuring a battery voltage, and prevents or avoids abnormal situations such as overdischarge, overcharge, and over-temperature of the battery.

The battery replacement of the electric vehicle can be applied to various scenes, such as an electric vehicle battery replacement system arranged in a highway or a common road, or a point multi-vehicle battery replacement system arranged in a community, and the like.

The embodiment of the application takes an electric vehicle battery replacement system (or referred to as a battery replacement station) in a mining area as an example to explain an application scene of electric vehicle battery replacement. As shown in fig. 1, a mine area power exchanging station 100 is provided, and the power exchanging station 100 includes the following areas: a management system 101, a battery swap area 102, a vehicle passage area 103, a transformer cabin 104, and a station power utilization area 105.

The management system 101 implements management of one or more of: the method comprises the steps of whole station control, charging control, battery replacement control, fire fighting system control, video monitoring and/or on-site monitoring.

And the whole station control is used for controlling the operation of the whole power change station. The whole station control carries out communication and information interaction with one or more units of charging control, battery replacement control, fire fighting system control, video monitoring and local monitoring, and carries out energy scheduling and energy utilization optimization according to the summary information, so that the whole station is safe and reliable to operate. And the charging control is used for controlling the charging and discharging process of the battery according to the current residual electric quantity condition of the battery. The battery replacement control is used for controlling battery peripheral equipment such as the battery replacement robot and the battery replacement connector. The fire-fighting system control is used for suppressing and extinguishing fire by controlling the fire-fighting system when the emergency fire accident occurs in the power station, so that the power station can run safely. The video monitoring is used for comprehensive video monitoring of all systems in the power conversion station. The in-situ monitoring is used for carrying out charging monitoring, battery replacement monitoring, vehicle monitoring, power distribution monitoring and environment monitoring on line in real time.

The battery swapping area 102 is used to provide a replacement platform for the vehicle battery. The battery changing area comprises a battery changing platform, a charging bin and a battery changing mechanism. The battery replacement platform is used for providing a parking and battery replacement operation area for the battery replacement vehicle; the charging bin is used for charging the battery; the battery replacing mechanism comprises a battery replacing robot, a battery replacing connector and the like and is used for taking out the battery from the charging bin or putting the battery into the charging bin.

The vehicle passage area 103 is an area through which vehicles can pass.

The voltage transformation cabin 104 is provided with a power distribution room and a power distribution cabinet, and is used for converting high-voltage electricity of a power grid into voltage required by each device in the power transformation station. Each device voltage includes one or more of: the power supply system comprises voltage required by the power conversion system, working voltage of a relevant controller, power consumption voltage of a daily station and the like.

The station power utilization area 105 is an area where daily-use electric appliances such as air conditioners, lamps, and/or power supplies are installed in the power conversion station.

At present, when an electric vehicle arrives at a battery replacement station, the electric vehicle enters a battery replacement area and stops at a battery replacement platform. The battery replacement control system controls the battery replacement robot to detach the battery with insufficient electric quantity of the electric vehicle, take out the battery with full electric quantity from the charging bin and install the battery on the electric vehicle, and place the battery with insufficient electric quantity into the charging bin. The battery replacement system charges the battery with insufficient electric quantity. And the electric vehicle is pulled out of the battery changing station to continue to move forwards after the battery changing process is finished. However, when there is no fully charged battery in the battery changing station, the battery can be changed only when the electric vehicle arrives at the battery changing station and waits for the fully charged battery in the battery changing station, which results in an overlong waiting time for the electric vehicle.

Based on this, the embodiment of the application provides an electric vehicle battery changing system and a battery pack charging method, when the electric quantity of an electric vehicle is judged to be insufficient, at least one battery pack is fully filled in a charging bin near the electric vehicle in advance, so that when the electric vehicle reaches the charging bin, the process of waiting for the charging of the battery pack is not needed, and the process of changing the battery of the electric vehicle is shortened.

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

As shown in fig. 2, the electric vehicle battery replacement system of the present embodiment.

The electric vehicle battery replacement system comprises a management system 210, N energy storage converters (PCS 220), any one of the PCS comprising a bidirectional direct current-alternating current (DC-AC) charging module 230 and M battery packs 241; m is the product of a and N, a is an integer greater than 1, and N is an integer greater than 1.

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

The DC-AC charging module of the PCS is electrically connected to a parallel battery packs. A switching device 242 is provided between any one of the battery packs and the DC-AC charging module to which it is connected. And the DC-AC charging module is used for selecting the accessed battery pack according to the power distributed by the PCS and by opening and closing the switching device under the control of the management system, and charging the battery pack. The number of DC-AC charging modules is N, and N is an integer greater than 1.

The battery pack may be formed by connecting a plurality of battery units in series, or may be a single battery unit, which is not limited in the embodiments of the present application.

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

For example, the cloud server may refer to a server providing a service for a vehicle, and when the electric vehicle travels to an area served by the cloud server, the cloud server may obtain the battery capacity of the electric vehicle.

In the embodiment of the application, the method for acquiring the electric quantity of the real-time battery of the operation electric vehicle based on the cloud server can comprise the following steps:

the first method is as follows: the management system periodically sends a request instruction to the cloud server to request to acquire the real-time battery electric quantity of the electric vehicle. And based on the request instruction sent by the management system, the cloud server sends the real-time battery electric quantity of the electric vehicle to the management system.

The second method comprises the following steps: the cloud server periodically and actively sends the real-time battery electric quantity of the electric vehicle to the management system.

The management system is also used for connecting the target battery pack with the target DC-AC charging module through the switching device and controlling the PCS to rapidly charge the target battery pack through the target DC-AC charging module at the maximum power which can be borne by the target battery pack under the condition that the battery capacity is lower than the first capacity value and the M battery packs are not fully charged; the target battery pack is the battery pack with the largest electric quantity in the M battery packs, or the target battery pack is the battery pack with the electric quantity of the M battery packs larger than the second electric quantity value and supporting quick charging.

The management system can be divided into a local management system and a remote management system, the local management system is responsible for controlling and monitoring protection of a battery report and a PCS (personal communications system) of the local battery replacement station, and the remote management system is responsible for coordinating the vehicle and the work of the battery replacement station.

In the embodiment of the application, if the electric quantity of the battery is lower than the first electric quantity value, it indicates that the electric vehicle needs to be charged or the battery is replaced, and the M battery packs are not full of electric battery packs, which indicates that the electric vehicle battery replacing system cannot timely provide the full of electric batteries for the electric vehicle, and if the full of electric batteries are not timely obtained, the electric vehicle may need to wait. The first electric quantity value may be a preset value, for example, any value between 0% and 20%, and the first electric quantity value is not particularly limited in the embodiments of the present application.

Therefore, when the battery capacity of the electric vehicle is lower than the first capacity 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 switching device and control the target DC-AC charging module to rapidly charge the target battery pack with the maximum power that the target battery pack can bear, so that the battery replacement station can prepare the fully charged battery pack for the electric vehicle as soon as possible, and the time for the electric vehicle to wait for the charging of the battery pack is reduced.

The target battery pack can be the battery pack with the largest electric quantity in the M battery packs, so that the battery pack with the largest electric quantity can be charged into a fully charged battery pack quickly, the time length of the electric vehicle waiting for charging the battery pack is shortened, and the fully charged battery pack can be directly obtained when the vehicle arrives at a battery replacement station.

Alternatively, the target battery pack may be a battery pack in which the electric quantity of the M battery packs is greater than the second electric quantity value and fast charging is supported. Where fast charging may refer to supporting fast charging as referred to in the fast charging protocol. Therefore, the battery pack which supports quick charging and has relatively sufficient electric quantity can be quickly charged into a fully charged battery pack, the time for waiting for charging the battery pack of the electric vehicle is shortened, and the fully charged battery pack can be directly obtained when the vehicle arrives at the battery replacement station.

In fig. 2, the management system may implement wired or wireless communication with the PCS, the switching device, the server, and the like, which is not shown in the figure, and the communication method between the devices that need to communicate is not specifically limited in the embodiment of the present application.

Optionally, on the basis of fig. 2, the management system in the embodiment of the present application is specifically configured to find a battery pack with the largest electric quantity among the M battery packs or a battery pack with an electric quantity larger than a second electric quantity among the M battery packs under the condition that the electric quantity of the battery is lower than a first electric quantity value and the M battery packs are not fully charged, connect the battery pack and the corresponding DC-AC charging module through the switching device, and disconnect the other a-1 battery packs from the corresponding DC-AC charging module.

For example, the management system may control the output power of the PCS corresponding to the battery pack, and the DC-AC charging module may rapidly charge the battery with the maximum power that the target battery pack can bear. In addition, in the embodiment of the application, the connection between the other a-1 battery packs and the corresponding DC-AC charging modules is disconnected, so that the DC-AC charging modules can only charge the target battery pack, the charging efficiency of the target battery pack is further improved, the target battery pack can be further rapidly charged into a fully charged battery pack, and the charging time of the target battery pack is shortened.

Optionally, on the basis of fig. 2, the management system in the embodiment of the present application is further specifically configured to find a battery pack with the largest electric quantity among the M battery packs, or a battery pack with an electric quantity larger than the second electric quantity value among the M battery packs, but a target DC-AC charging module corresponding to the battery pack is disconnected from the bus, so that charging cannot be performed. And controlling any battery pack except the target battery pack in the M battery packs to realize the quick charging of the target battery pack. By the steps, the battery pack close to full charge or the battery pack with more residual electric quantity in the power conversion station can be quickly charged in the power grid section network mode, and the battery charging time is saved.

Optionally, on the basis of fig. 2, a plurality of battery units are included in any battery pack. The management system of the embodiment of the application is further configured to configure a first power for any one of the DC-AC charging modules when the electric quantity of the M battery packs is greater than the first electric quantity value, and/or when a fully charged battery pack exists, so that any one of the DC-AC charging modules charges a battery packs connected in parallel through the first power, where the first power is related to the electric quantity of each battery unit in the a battery packs connected in parallel.

For example, the management system can collect the maximum chargeable current of each battery pack in real time through EtherCAT, and the management system controls the PCS to configure appropriate first power for the DC-AC charging modules respectively, so that each DC-AC charging module charges the parallel battery packs through the appropriate power, and the appropriate first power is related to the electric quantity of each battery unit in the parallel battery packs. Therefore, when the electric vehicle does not need to be charged urgently or a full-charge battery is arranged in a battery replacement station, the battery pack is charged by adopting proper power, the influence of quick charging on the service life of the battery pack is reduced, and the performance of the battery pack is improved.

Optionally, the manner of calculating the first power may be:

firstly, the system obtains the optimum operation power of the battery pack through a value checking mode according to the battery voltage and a battery data manual, and the optimum operation power is recorded as sopcL.

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

wherein, the power of each battery cluster (or called as battery unit) is bmmspower [ n ].

Obtaining the proportion of each battery cluster:

bmspowerscale[n]＝bmspower[n]/power

obtaining the maximum charge-discharge power supported by each cluster of batteries:

power_bms[n]＝sopcL/bmspowerscale[n]

obtaining a first power actually meeting the demand:

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

the system operates according to the SOPC, and each cluster can not exceed the highest charge-discharge capacity of the battery until the battery capacities are consistent and the divided electric quantity is consistent.

The unit of the power may be kw.

Optionally, on the basis of fig. 2, the management system is further configured to control some or all of the M battery packs to charge the bus through the corresponding DC-AC charging modules when the electric energy of the bus is lower than a threshold. Therefore, when the electric energy of the power grid is lower than the threshold value, the battery pack of the power conversion station charges the bus through the DC-AC module and feeds the electric energy back to the power grid, so that the peak regulation and frequency modulation of the power grid are realized, the pressure of the power grid is relieved, and the stability of the power grid is maintained.

The DC-AC charging module can 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 an energy storage battery charging instruction, the bidirectional DC-AC electric module receives the electric energy of a power exchanging station from the energy storage converter and charges the battery through the electric energy of the power exchanging station; and after receiving the discharge instruction of the energy storage battery, the bidirectional DC-AC electric module discharges to the power grid through the energy storage converter.

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

Optionally, on the basis of fig. 2, the management system includes: the system comprises a PCS control unit, a BMS unit, a whole station control unit, a battery replacement control unit, a video monitoring unit, a fire fighting system control unit and an on-site monitoring unit. The details will be described in the following embodiments and will not be described herein.

In order to more clearly illustrate the electric vehicle battery replacing system in the embodiment of the present application, fig. 3 shows a specific battery replacing station schematic diagram.

As shown in fig. 3, the power conversion station may include a power distribution room, and a plurality of transformers may be disposed in the power distribution room, and the plurality of transformers may change the voltage of the bus bar to different voltage values to charge the battery pack or supply power to devices in the power conversion station.

For example, the bus may be a 35KV bus, the transformer for charging the battery pack may be a 3MVA step-up transformer, and the transformer for supplying power to the equipment in the battery replacement station may be a transformer for a 500KVA station, and in a possible implementation, the transformer for the 500KVA station may further obtain 380V voltage through the low-voltage power distribution cabinet to supply power to the equipment in the battery replacement station.

The device in the battery swapping station may be referred to as a load, and includes, for example: a battery replacement mechanism (also referred to as a battery replacement system), an air conditioner, a lamp, a Power Supply, a ground charging station, an Uninterruptible Power Supply (UPS), and the like.

The UPS may provide power for a management system, including, for example: the system comprises a PCS control unit, a BMS unit, a whole station control unit, a battery replacement control unit, a video monitoring unit, a fire fighting system control unit and an on-site monitoring unit.

The PCS control unit is used for controlling the PCS to realize efficient and rapid charging and discharging of the battery pack. The BMS unit may 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 whole management of the power swapping station. The video monitoring unit can be used for video monitoring in the power swapping station. The fire protection system control unit can be used for controlling fire protection equipment in the power conversion station. The in-situ monitoring unit may be used to enable monitoring local to the monitoring device.

It can be understood that there may be a plurality of battery replacement sites in the battery replacement station, and therefore a plurality of branches may be led out from the 3MVA step-up transformer to the plurality of battery replacement sites, any battery replacement site may include an electric vehicle battery replacement system, and the electric vehicle battery replacement system may include a PCS, a battery system, and the like. The battery system may include a plurality of battery packs, a BMS corresponding to each battery pack, a switching device corresponding to each battery pack, a switching power supply, and the like, and the switching power supply may be used to supply power to the switching device and the like, and the plurality of battery packs may be connected in parallel. A plurality of battery package are parallelly connected, can realize the automatic equalization of electric quantity between the battery package to and can select the parallelly connected side in a flexible way and put into rechargeable battery package quantity, it is convenient that the system inserts, can shorten charge time through reducing rechargeable battery package quantity.

The power swapping station can be understood from three levels from large to small, for example, the first level: the battery replacing station comprises an electric vehicle battery replacing system for realizing battery replacing and electric equipment in the battery replacing station. A second layer: the electric vehicle battery replacing system related to battery replacing comprises a PCS, a battery pack, related connecting pieces and the like. When assisting the electric vehicle battery replacement system on the second layer to realize automatic battery replacement of the electric vehicle, the electric vehicle battery replacement system can further comprise a third layer: the battery replacing mechanism comprises a battery replacing robot, a battery replacing connector and the like, and can realize automatic battery replacing of the electric vehicle, so that the labor is saved.

In possible realization, the electric vehicle battery replacing system comprises 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 electricity distribution room is connected with a plurality of PCS and switch board electricity respectively. The distribution room provides 380V electric energy input for the PCS and the distribution cabinet. The power distribution cabinet provides electric energy input with proper voltage for the load. The load includes an air conditioner, a lamp, and the like.

The PCS is used for bidirectional conversion of electric energy and controls the charging and discharging processes of the battery. Specifically, the PCS rectifies alternating current of a power grid into direct current, and supplies the direct current to the battery pack for charging. The PCS inverts the direct current of the battery pack into alternating current, and transmits the alternating current to a power grid to discharge the battery. Besides, the PCS supports charging power setting, charging and discharging mode setting and the like, and the control mode 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. A plurality of battery packs are arranged under each battery pack, and the battery packs are connected in parallel. And a switching device is connected between any one of the parallel battery packs and the corresponding DC-AC charging module, and the switching device is used for selecting the battery pack accessed to the DC-AC charging module according to the control of the management system.

A switching power supply is electrically connected to the BMS and may be used to provide the BMS unit with a 24V operating voltage. The BMS unit is used for monitoring the residual electric quantity SOC and the state of health SOH of the battery pack and feeding back the battery condition to the management system. Further, the management system may determine whether there is a battery pack that needs to be maintained in the battery health state according to the SOH of the battery pack, and if there is a battery that needs to be maintained in the battery health state, discharge the battery pack that needs to be maintained in the battery health state.

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

The management system is provided with electric energy by an Uninterruptible Power Supply (UPS), and the UPS is electrically connected with the power distribution cabinet. The UPS obtains electric energy from the power distribution cabinet and converts the electric energy into 220V voltage to be output to the management system.

The management system acquires the residual electric quantity of the battery of the running electric vehicle from the cloud server, and the residual electric quantity of the battery is monitored by the vehicle-mounted BMS unit and is uploaded to the cloud server. The management system judges whether the electric vehicle needs to be replaced urgently, and if the electric quantity of the electric vehicle battery is detected to be insufficient, the electric vehicle is informed to be started to an adjacent replacing station to replace the battery.

The battery replacement system further comprises a battery replacement mechanism. The battery replacement mechanism can comprise a battery replacement robot and a battery replacement connector. The battery replacing mechanism is used for taking out or putting the battery into the charging bin. Specifically, when the electric vehicle stops at the battery replacing platform, the battery replacing robot detaches the battery with insufficient electric quantity of the electric vehicle, takes out the battery with full electric quantity from the charging bin and installs the battery on the electric vehicle, and puts the replaced battery with insufficient electric quantity into the charging bin.

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

In a first possible implementation, the management system finds out the battery pack with the highest electric quantity in all the battery packs or the battery pack with the electric quantity larger than 60% in all the battery packs according to the electric quantity condition of all the battery packs acquired by the BMS unit when the BMS unit detects that the electric quantity of all the batteries in the current charging bin is lower than 90% and the battery packs are not fully charged, connects the battery pack with the corresponding DC-AC charging module through the switching device, and disconnects the rest of the battery packs from the corresponding DC-AC charging module. According to the maximum input power of the battery pack collected by the BMS unit, the management system controls the PCS, and the DC-AC charging module is used for rapidly charging the battery pack with the maximum power which can be borne by the battery pack.

In a second possible implementation, the management system detects that the electric quantity of all the batteries in the current charging bin is lower than 90% through the BMS unit, and finds the battery pack with the highest electric quantity in all the battery packs or the battery pack with the electric quantity larger than 60% in all the battery packs according to the electric quantity condition of all the battery packs collected by the BMS unit under the condition that the battery packs are not fully charged. If the battery pack is disconnected from the bus and cannot be charged, the battery pack and the corresponding DC-AC charging module are connected through the switching device, and any other battery pack except the battery pack is controlled to be charged quickly.

In a third possible implementation, the management system detects, through the BMS unit, that there is more than 90% of the battery packs in all the battery capacities in the current charging bin, or in the case of a fully charged battery pack, respectively configures appropriate power for each DC-AC charging module, so that each DC-AC charging module charges the parallel battery packs with the appropriate power, which is related to the capacities of the respective battery units in the parallel battery packs. Any one of the battery packs includes a plurality of battery cells therein.

In order to fully utilize resources, the management system controls the electric energy transmission direction in the battery replacement system according to the battery health state and the electric energy of the power grid.

For example, when the management system detects that there are more fully charged battery packs through the BMS unit, the number of battery packs requiring charging is small, and the power of the bus is below a threshold, the management system controls the PCS power transmission direction to charge part or all of the battery packs to the bus through the DC-AC charging module.

In possible implementation, a management system of the battery replacement station acquires the residual electric quantity of the battery of the running electric vehicle from the cloud server, and the residual electric quantity of the battery is monitored by the vehicle-mounted BMS unit and is uploaded to the cloud server. The management system judges whether a vehicle needs to be changed or not, and if the vehicle needs to be changed or not, the BMS unit monitors whether a fully charged battery exists in a charging bin of the battery changing station or not. When the battery is not fully charged, the management system informs the PCS control unit to set the charging power and the charging mode of the PCS, so that the target battery pack is quickly fully charged on the premise of safety. And if the current running vehicle is detected to be in urgent need of replacing the battery, charging the target battery pack with proper power.

And the whole station control is used for controlling the operation of the whole power change station. The whole station control is communicated and interacted with the PCS control unit, the BMS unit, the battery replacement control unit, the video monitoring unit, the fire fighting system control unit and the local monitoring unit, and energy scheduling and energy utilization optimization are carried out according to the summary information, so that the whole station is safe and reliable to operate.

And the battery replacement control is used for realizing the control of battery peripheral equipment such as the power replacement robot and the power replacement connector.

The fire-fighting system control is used for suppressing and extinguishing fire by controlling the fire-fighting system when an emergency fire accident occurs to the power switching station, so that the power switching station can operate safely.

The video monitoring is used for realizing comprehensive video monitoring of all systems in the power conversion station.

The in-situ monitoring is used for carrying out charging monitoring, battery replacement monitoring, vehicle monitoring, power distribution monitoring and environment monitoring on line in real time.

To sum up, this application embodiment has used energy storage PCS to replace traditional electric pile that fills, realized can be to the charge-discharge function of battery, improve system efficiency 5% simultaneously, reduce the module part cost that charges more than 50%, and charging power can be more nimble receive station control system's (or called management system) control, management system can be according to current electric core, the temperature, SOC and the flexible control PCS's that is operating the vehicle SOC at present charge, information that management system accessible high in the clouds transmitted detects that there is the vehicle urgent need to trade the electricity, and when not having full-charge battery in the current position in storehouse, the more battery package of steerable electric quantity, full charge fast with the maximum power that the battery can bear, if it is not urgent need to trade the electricity to detect the current operation vehicle, charge with the more suitable power of battery. The flexible charging mode is also beneficial to the parameters of the service life, the safety, the endurance mileage and the like of the battery.

Trade the communication in the station and can adopt EtherCAT distributing type slave station framework, because it is big to trade power station area, it is numerous that total accuse needs information collection, the wiring degree of difficulty is great, and in case the communication problem maintenance is more complicated appears in the operation device, consequently, adopt distributed architecture to arrange each slave station module to trade the electric region, the vehicle is current regional, it is regional to become ballast, etc., the control cabin is arranged to total accuse, through the real-time ethernet communication mode of EtherCAT industry, slave station module can insert local digital quantity signal nearby, analog quantity signal, 485 signals, the very big length that has shortened the pencil, the quality of communication has been guaranteed, and EtherCAT expansibility is strong, be favorable to field station later stage increase-volume and new function development.

But utilize EtherCAT technique real-time detection station internal battery information and linkage direct current circuit breaker, the action of medium voltage switchgear can in time be moved when major problems appear, prevents that the accident from stretching.

By adopting the quick parallel technology of the batteries, the number of rechargeable batteries put into the parallel side can be flexibly selected, the charging and discharging can be maintained through the PCS, the system is convenient to access, and the charging time is shortened.

Because the battery package design needs to satisfy demands such as electric quantity, voltage, electric current simultaneously, therefore the battery package adopts the multiunit form of connecting in parallel usually, because the vehicle operation leads to many packages discharge inconsistent, it is inconsistent to lead to distributing the electric current between each group battery to fill the completion after the completion of charging, consequently the current inconsistent between the cluster probably leads to PCS output power to distribute each group battery electric current uneven, traditional electric pile that fills leads to distributing great group battery electric current great when high-power charges, lead to charging and overflowing, can not guarantee that each group battery charges with best power, this application embodiment can gather the maximum chargeable electric current of every group battery in real time through EtherCAT, and control PCS and guarantee PCS to operate with preferred power, and realize quick charge, promote the security and the life-span of battery package again.

The power grid system can be accessed to adjust the peak frequency and the frequency of the power grid when the power conversion station is idle, so that the pressure of the power grid is relieved, and a better economic value is created.

Management system can realize leaving the net, because near the electric wire netting of mine is unstable, when meetting the unplanned power failure that the external accident leads to, can lead to the sudden commercial power in the station, if trade the electric equipment and snatch battery in-process and break off the power suddenly, have the battery risk of dropping, PCS supports the function of leaving the net, when 6KV cuts off the power suddenly, the system can be with well head cabinet 6KV switch disconnection, PCS can follow the more battery package of electric quantity simultaneously and get the electricity, for control electricity in the station and trade the power supply of electric robot, guarantee that the vehicle trades the electricity normally to go on at present.

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

Other embodiments of the present application will be apparent to those skilled in the art from consideration of the specification and practice of the aspects disclosed herein. This application is intended to cover any variations, uses, or adaptations of the invention following, in general, the principles of the application and including such departures from the present disclosure as come within known or customary practice within the art to which the invention pertains. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the application being indicated by the following claims.

It will be understood that the present application is not limited to the precise arrangements described above and shown in the drawings and that 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

1. An electric vehicle battery replacement system is characterized by comprising 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 larger than 1, the N is an integer larger than 1, and any PCS comprises a bidirectional direct current-alternating current DC-AC charging module;

the PCS is connected into a bus through a transformer;

any one of the DC-AC charging modules is connected with a battery packs connected in parallel in the M battery packs, a switch device is connected between any one of the a battery packs connected in parallel and any one of the DC-AC charging modules, and the switch device is used for selecting the battery pack accessed to the DC-AC charging module according to the control of the management system;

the management system is used for acquiring the battery electric quantity of the electric vehicle from a server, the server is a cloud server which is in real-time interaction with the electric vehicle, and the server stores the real-time battery electric quantity of the electric vehicle;

the management system is further used for connecting a target battery pack to a target DC-AC charging module through the switching device and controlling the target DC-AC charging module to rapidly charge the target battery pack at the maximum power which can be borne by the target battery pack under the condition that the battery capacity is lower than a first electric quantity value and the M battery packs are not fully charged; the target battery pack is a battery pack with the largest electric quantity in the M battery packs, or the target battery pack is a battery pack which has the electric quantity larger than a second electric quantity value and supports quick charging.

2. The system as claimed in claim 1, wherein the management system is specifically configured to connect a target battery pack to a target DC-AC charging module through the switching device and disconnect the target DC-AC charging module from another a-1 battery packs and control the target DC-AC charging module to rapidly charge the target battery with the maximum power that the target battery can bear when the battery capacity is lower than a first capacity value and the M battery packs are not fully charged.

3. The electric vehicle battery replacement system according to claim 1 or 2, wherein the management system is further configured to control any battery pack, except the target battery pack, of the M battery packs to realize rapid charging of the target battery pack when the target DC-AC charging module is disconnected from the bus.

4. The electric vehicle charging system as claimed in claim 1 or 2, wherein a plurality of battery units are included in any one of the battery packs;

the management system is further configured to configure a first power for any one of the DC-AC charging modules when the battery capacity is greater than the first capacity value and/or when there is a fully charged battery pack in the M battery packs, so that the any one of the DC-AC charging modules charges the a parallel battery packs with the first power, where the first power is related to the capacity of each battery unit in the a parallel battery packs.

5. The electric vehicle battery replacement system according to claim 1 or 2, wherein a switch is arranged between the bus and the power grid;

the management system is further used for controlling the bus to disconnect a power grid through the switch when the electric energy of the bus is lower than a threshold value, and controlling part or all of the M battery packs to charge the bus through corresponding DC-AC charging modules so as to supply power to a load connected to the bus.

6. The electric vehicle battery swapping system of claim 1 or 2, wherein the management system comprises: the system comprises a PCS control unit, a BMS unit, a whole station control unit, a battery replacement control unit, a video monitoring unit, a fire fighting system control unit and an on-site monitoring unit;

the PCS control unit is used for controlling the PCS to charge and discharge the battery pack; the BMS unit is used for managing the state of the battery pack; the whole station control unit is used for managing the whole power change station; the video monitoring unit is used for monitoring videos in the power swapping station; the fire fighting system control unit is used for controlling fire fighting equipment in the power swapping station; the in-situ monitoring unit is used for monitoring the local condition of the equipment.

7. A charging method of a battery pack is applied to the electric vehicle battery replacing system as claimed in any one of claims 1-6, and the method comprises the following steps:

acquiring the battery capacity of an electric vehicle from a server, wherein the server is a cloud server which interacts with the electric vehicle in real time, and the server stores the real-time battery capacity of the electric vehicle;

under the condition that the battery capacity is lower than a first capacity value and M battery packs are not fully charged, connecting a target battery pack with a target DC-AC charging module through a switching device, and controlling the target DC-AC charging module to rapidly charge the target battery pack at the maximum power which can be borne by the target battery pack; the target battery pack is a battery pack with the largest electric quantity in the M battery packs, or the target battery pack is a battery pack which has the electric quantity larger than a second electric quantity value and supports quick charging.

8. The method of claim 7, wherein the connecting a target battery pack to a target DC-AC charging module through a switching device and controlling the target DC-AC charging module to rapidly charge the target battery pack at a maximum power that the target battery pack can bear comprises:

and connecting the target battery pack with the target DC-AC charging module through the switching device, disconnecting the target DC-AC charging module from the other a-1 battery packs, and controlling the target DC-AC charging module to rapidly charge the target battery at the maximum power which can be borne by the target battery.

9. The method of claim 7 or 8, further comprising:

and when the target DC-AC charging module is disconnected with the bus, controlling any battery pack except the target battery pack in the M battery packs to realize the quick charging of the target battery pack.

10. The method of claim 7 or 8, wherein a plurality of battery cells are included in any one of the battery packs; the method further comprises the following steps:

and when the battery capacity is larger than the first capacity value and/or when full-charge battery packs exist in the M battery packs, configuring a first power for any one DC-AC charging module, so that the any one DC-AC charging module charges the a parallel battery packs through the first power, wherein the first power is related to the capacity of each battery unit in the a parallel battery packs.