Battery charging complex for electric vehicle fleets

Abstract

The present invention relates to a charging complex for electric vehicle groups used according to urban needs, and is applicable to the transportation industry and local public enterprises. The object of the present invention is to provide a battery charging complex for electric vehicle groups, which includes a group of electric vehicles of the same type and a group of charging stations including buffer batteries, wherein the drive batteries and buffer batteries are of the same type, the buffer batteries are represented by previously used drive batteries, and have a storage capacity of 60-80% of the nominal storage capacity. The present invention aims to achieve the technical result of extending the useful life of electric vehicle drive batteries by continuously using them as buffer batteries in the charging stations of the battery charging complex for electric vehicle groups. Dependent claim 3, 2 drawings.

Description

Technical Field

[0001] The present invention relates to a charging complex for an electric vehicle group used according to urban needs and is applicable in the transportation industry and local public utilities.

Background Art

[0002] The battery charging system for an electric vehicle group is known, and the system includes an electric bus including a driving battery, a driving motor, and a connection device to a charging station, and a charging station. [US Patent Application Publication No. 2022 / 407349(A1), Publication Date: December 22, 2022]

[0003] The disadvantage of the prior art is that there are no preconditions and technical means for tracking the deterioration of the characteristics of the driving battery used to drive the driving motor of the electric bus and extending the useful life by timely utilization or reprofiling of the driving battery.

[0004] A complex for optimizing the use of the batteries of an electric vehicle group has been selected as a prototype, and the complex includes a driving battery equipped with a condition monitoring system, a driving motor, and a homogeneous group of electric vehicles equipped with a connection device to a charging station. The monitoring system is configured to dynamically or periodically record data regarding the driving battery, which includes tracking the current and initial states of the temperature during charge and discharge of the driving battery, the nominal or assumed calendar life, voltage, energy density, depth of discharge, and other data. Based on these data, an approximate life or expiration date of the driving battery is determined, and recommendations are made as to whether the driving battery should be diverted, sold for recycling, or discarded. [International Publication No. 2020 / 036984(A1), Publication Date: February 20, 2020]

[0005] Advantageously, the prototype can provide recommendations as to whether to divert the driving battery or sell it for reuse based on data obtained from the monitoring system of the driving battery.

[0006] However, a common drawback of both prototypes and conventional technologies is the lack of concrete means to provide a viable option for the effective reuse of drive batteries that are unsuitable for driving electric vehicle motors but are not yet completely unusable.

[0007] Conventional technologies only propose the possibility of recycling drive batteries. However, known drive battery disposal and recycling technologies remain incomplete, problematic, and extremely costly, raising concerns that global infrastructure may not be able to cope with the enormous amount of battery waste generated by the proliferation of electric vehicles. This stems from the fact that battery packs must be disassembled at least to the module level in order to improve the efficiency of the battery collection and recycling process. However, disassembling drive batteries involves many risks.

[0008] Disassembly of drive batteries requires training in high-voltage work to prevent electric shock or short circuits. Short circuits can cause rapid discharge, which can lead to overheating and thermal runaway. Thermal runaway generates particularly harmful by-products, including hydrogen fluoride gas, which, along with other gaseous products, can cause explosions of battery components. Battery cells pose chemical hazards due to flammable electrolytes, toxic and carcinogenic electrolyte additives, and potentially toxic or carcinogenic electrode materials. While dry and wet smelting methods have been developed to improve the recycling efficiency of drive batteries, they suffer from high initial investment costs and low quality recovered metals. Therefore, there is an urgent need for alternative methods to ensure that end-of-life drive batteries are fully suitable as a source of secondary raw materials.

[0009] In contrast to the utilization of drive batteries, while reprofiling technologies for drive batteries exist, they are currently immature and do not offer concrete and simple solutions for the reuse of drive batteries in existing industries. [Prior art documents] [Patent Documents]

[0010] [Patent Document 1] U.S. Patent Application Publication No. 2022 / 407349(A1) [Patent Document 2] International Publication No. 2020 / 036984(A1) [Overview of the Initiative] [Problems that the invention aims to solve]

[0011] Given the existing shortcomings, there is a strong need for the development of effective technological solutions that improve the performance of existing solutions in the field of optimizing battery utilization by reusing electric vehicle drive batteries before they become completely unusable. [Means for solving the problem]

[0012] This invention aims to solve the technical problem of improving the performance characteristics of a composite system for optimizing the use of batteries in electric vehicle fleets.

[0013] The present invention aims to achieve a technical result that extends the useful life of an electric vehicle's drive battery by continuously operating it as a buffer battery in a charging station of a battery charging complex for a group of electric vehicles.

[0014] The objectives of this invention are as follows:

[0015] The battery charging complex for the electric vehicle group includes a group of identical electric vehicles, each equipped with a drive battery with a condition monitoring system, a drive motor, and equipment for connecting the drive battery and drive motor to a charging station. In contrast to the prototype, this complex further includes a group of charging stations, each equipped with a buffer battery with a condition monitoring system. The drive batteries of the electric vehicles and the buffer batteries of the charging stations are of the same type, and the buffer batteries of the charging stations are represented by the used drive batteries of the electric vehicles in the aforementioned group of electric vehicles, with a capacity of 60-80% of the nominal capacity.

[0016] A battery charging complex for electric vehicle groups provides the potential to replenish the energy of land vehicles primarily used in cities or local municipalities. The same type of electric vehicle group included in the scope of this invention refers to electric buses or trolleybuses with extended autonomous driving range, or electric freight vehicles equipped with drive batteries and driven by drive motors. Furthermore, it also includes passenger cars used as taxis or rental cars, and unmanned autonomous vehicles. The same type of electric vehicle group may also include special vehicles and commercial vehicles, which may be represented by vehicles for cleaning, repair, or other similar purposes. To receive electrical energy from a charging station, the electric vehicle includes a connection device to the charging station, which may be represented by any known type of current collector or electrical connector, such as CCS2, CHAdeMO, or wireless electrical energy transmission equipment.

[0017] The charging station group included in the scope of the present invention refers to an element of urban infrastructure that supplies power for charging electric vehicles. Each charging station comprises at least one of the following components connected in series: an input unit for connecting to an AC power source, a surge protector, a circuit breaker, a contactor for switching the input AC current, a power unit for converting AC current to DC current, a buffer battery for storing electrical energy, a power unit for converting DC current of one magnitude to DC current of another magnitude, a contactor for switching the output DC current, a charging connector, a charging dome or charging platform, a user interface, and a controller to which the following elements are connected: a power unit, a buffer battery, and a contactor for switching the input AC current and output DC current.

[0018] The AC input section provides a means of obtaining power from a general-purpose power grid and may be represented by a feeder or other device for connecting to high-voltage electrical circuits. Surge protection devices protect the station's components from short-term voltage rises and impulses caused by lightning discharges, operation within the power grid, switching of power systems, etc. Surge protection devices may be represented by varistor limiters, arresters, etc. Circuit breakers protect electrical circuits from overload and short-circuit currents. Such circuit breakers may be represented by mechanical or electronic switchgear.

[0019] The contactor that switches the input AC current is designed for emergency disconnection from the AC power grid. The power unit that converts AC current to DC current may be represented by an inverter, rectifier, or other device that provides a similar function.

[0020] A buffer battery reduces DC voltage fluctuations in the circuit and stores electrical energy, enabling shorter charging times for electric vehicles. A power unit that converts one DC current to another allows control over the characteristics of the output charging current. A contactor that switches the output DC current is designed to disconnect the charging connector from the buffer battery and interrupt the electric vehicle charging process. Contactors present in a charging station may be represented by electromagnetic devices and other devices.

[0021] The controller provides the capability to control the charging process and, for this purpose, is connected to contactors that switch the input AC current and contactors that switch the output DC current, and can transmit control signals. The controller is also configured to modify the characteristics of the DC current converted by the power unit. This allows for smooth adjustment of the charging process and further reduces the risk of failure of components in the electric vehicle charging station. The controller is also connected to a power unit that converts AC current to DC current, and contactors that switch the input AC current and output DC current. This allows signals to be sent to the power unit and contactors to control the charging process. A buffer battery is also connected to the controller so that its status can be monitored. The connection between the controller and the aforementioned components may be made by wires, busbars, or cables. The user interface may be represented by data input / output devices connected to the controller.

[0022] Furthermore, the charging station may include a controller for communicating with the electric vehicle being charged via a charging connector.

[0023] The charging station may be mounted within an enclosure, cabinet, or panel that provides support and protection for the charging station. The components of the charging station may be secured by any known detachable or non-detachable connections.

[0024] The drive battery of an electric vehicle belongs to the same type as the buffer battery of the charging station. This ensures complete compatibility and guarantees the possibility of using the used drive battery of an electric vehicle as the buffer battery of the charging station without changing the design of the charging station. By this method, since the drive battery of an electric vehicle can be timely utilized as the buffer battery of the charging station, it becomes possible to extend the useful life of the drive battery in the battery charging complex of a group of electric vehicles. Lithium titanate (LTO), niobium titanate (NTO), lithium manganese (NMC), lithium iron phosphate (LFP) and other types of batteries can be presented as drive batteries and buffer batteries.

[0025] The previously used drive battery of an electric vehicle having a storage capacity in the range of 60% to 80% of the nominal capacity is presented as the buffer battery of the charging station. By this method of using the drive battery, the risk of the electric vehicle becoming inoperable is reduced, and furthermore, a sufficient life for reusing the drive battery as the buffer battery is ensured. The storage capacity is the amount of electricity supplied by the battery when discharging until the battery reaches the final voltage. During the first charge-discharge cycle, the storage capacity increases as the active material of the electrode plate is formed. During operation, the storage capacity remains stable for a certain period, and then gradually begins to decrease due to the deterioration of the active material of the electrode plate.

[0026] When the storage capacity of the drive battery exceeds 80% of the nominal capacity, the drive battery can be used to effectively and safely drive the drive motor of the electric vehicle without the risk of becoming inoperable due to a failure of the drive battery. When the storage capacity of the drive battery is less than 60% of the nominal capacity, the required storage capacity cannot be provided, and since it takes a long time to accumulate energy or the accumulation itself does not occur at all, the drive battery is considered unusable and not suitable for use as a buffer battery.

[0027] The present invention can be manufactured from known materials using known tools, which confirms that the invention satisfies the patent requirement of "industrial applicability."

[0028] The present invention is characterized by a series of essential features not previously known in the prior art, wherein the electric vehicle charging complex further includes a group of charging stations, each including a buffer battery equipped with a condition monitoring system, the electric vehicle's drive battery and the charging station's buffer battery are of the same type, and the charging station's buffer battery is represented by the used drive batteries of the aforementioned group of electric vehicles, with a storage capacity of 60-80% of its nominal capacity. This makes it possible to continuously operate a drive battery that is no longer suitable for supplying power to the electric vehicle's drive motor as a buffer battery for the charging station to store current, and to use it for charging the electric vehicle until the drive battery becomes completely unusable.

[0029] In a battery charging complex for an electric vehicle fleet, the technical achievement of extending the useful life of the electric vehicle's drive battery by continuously operating the drive battery as a buffer battery for the charging station, thereby improving the operational characteristics of the complex for optimizing the battery utilization of the electric vehicle fleet, is realized.

[0030] The present invention possesses a series of essential features not known in the prior art, thereby demonstrating that the present invention satisfies the patentability requirement of "novelty."

[0031] A remarkable feature of the present invention is that it is not found in the prior art, and in this respect, the present invention satisfies the "inventive step" requirement for patentability.

[0032] The present invention will be explained with reference to the following diagrams. [Brief explanation of the drawing]

[0033] [Figure 1] This is a top view functional diagram showing the functional configuration of the battery charging complex for a group of electric vehicles. [Figure 2] This is a functional diagram of an electric vehicle charging station. [Modes for carrying out the invention]

[0034] The following is an embodiment illustrating the feasibility of the essence of the present invention and to further enhance understanding. This embodiment can be arbitrarily modified or supplemented, and the present invention is not limited to this shown embodiment.

[0035] The battery charging complex for electric vehicle groups includes a group of electric vehicle charging stations (CS) 100 and a group of electric vehicles (EV) 200 for local governments, represented by electric buses.

[0036] Each charging station 100 includes, in series, an input unit 105 for connecting to an AC power source, a surge protection device 110, a circuit breaker 115, a contactor 120 for switching the input AC current, a power unit 125 for converting the AC current to a DC current, a buffer battery (BAT) 130 for storing electrical energy, the buffer battery (BAT) 130 having a system 131 for monitoring the state of the buffer battery, represented by sensors for monitoring temperature and electrical characteristics and a temperature control system, a power unit 135 for converting one magnitude DC current to another magnitude DC current, a contactor 140 for switching the output DC current, and a charging dome 145 for connecting to an EV.

[0037] The charging station also includes a controller 150 that controls contactors 120 and 140, to which a power unit 125, a buffer battery status monitoring system 131, a power unit 135, and a controller 155 that communicates with the EV being charged are connected via a data bus. A user interface 160, represented as a display and control panel, is connected to the controller 150. The charging dome 145 is externally fixed to the boom 165.

[0038] Each EV200 is represented as an electric bus, which includes a drive battery (BAT) 205 mounted on the roof. The drive battery is equipped with a condition monitoring system 206, which is represented by a control unit, sensors for monitoring the temperature and electrical characteristics of the drive battery, and a system for controlling the temperature of the drive battery. Meanwhile, each EV200 also includes a current collector 210.

[0039] The buffer battery 130 and the drive battery 205 are lithium titanate (LTO) batteries with a nominal storage capacity of 80 kW* / hour. The buffer battery 130 is represented by a used drive battery 205 with a capacity of 60-80% of its nominal capacity.

[0040] This invention operates as follows:

[0041] The charging station charges the buffer battery 130 in "idle" mode, and when the battery 130 reaches full charge, the charging station switches to "standby" mode.

[0042] When the electric vehicle's current collector 210 is connected to the charging dome 145, the controller 150 performs a functional diagnosis of the charging station. When the electric vehicle is positioned for charging, communication is established with the electric vehicle 200 to be charged via the controllers 150 and 155 and the charging dome 145, the contactor 140 is closed, and pre-charging is performed. During this pre-charging, the voltage between the drive battery 205 and the charging station 100 is equalized. Subsequently, the charging station 100 is switched to charging mode by the controller 150, at which point the controller calculates the maximum power that the charging station 100 can supply. The maximum power is calculated by the controller 150 according to the charge level and parameters of the buffer battery 130. If the charge level of the buffer battery 130 is above 20%, the power of the current supplied to the charging dome 145 is calculated based on the parameters of the buffer battery 130. If the charge level of the buffer battery 130 is below 20%, the power is limited to the maximum allowable power value obtainable from the power grid.

[0043] During the operation of the EV200 group, the energy intensity of the drive battery 205 gradually decreases to 80%. This process is recorded by a system 206 that monitors the status of the drive battery. When a predetermined energy capacity value is reached, the drive battery 205 can no longer adequately perform its primary function of driving the EV200's drive motor, and the EV200's driving range is significantly reduced. Furthermore, the reduced load capacity of the EV200 and the increased risk of battery 205 failure may cause the EV200 to become inoperable. Therefore, the drive battery 205 with reduced energy capacity is removed and incorporated into the circuit of the charging station 100 as a replacement for the failed buffer battery 130.

[0044] Since the stated storage capacity of battery 205 is sufficient to provide the function of a buffer battery 130 that reduces the load on the power grid during fast charging of the EV200, battery 205 is used until it becomes completely unusable, specifically until its storage capacity falls below 60%. After that, battery 205, which has been used as a buffer battery 130, is discarded, and the replacement cycle is repeated.

[0045] In this way, the drive battery 205, which is no longer suitable for use as a power source for the drive motor of the electric vehicle 200, is continuously used as a buffer battery 130 of the charging station to store current, and is guaranteed to be available for charging the electric vehicle 200 until it becomes completely unusable.

[0046] This achieves a technical success in which the useful life of the electric vehicle's drive battery is extended by continuously using the drive battery as a buffer battery for the charging station in the battery charging complex of the electric vehicle fleet, thereby improving the operational characteristics of the complex for optimizing the battery utilization of the electric vehicle fleet.

Claims

1. A battery charging complex for a group of electric vehicles, comprising a group of identical electric vehicles (200) each comprising a drive battery (205) equipped with a condition monitoring system (206), a drive motor, and a device for connecting the drive battery (205) and the drive motor to a charging station (100), further comprising a group of charging stations each comprising a buffer battery (130) equipped with a condition monitoring system (131), wherein the drive battery (205) of the electric vehicle (200) and the buffer battery (130) of the charging station (100) are lithium titanate batteries or niobium titanate batteries, and the buffer battery (130) of the charging station (100) is represented by the used drive battery (205) of the electric vehicle (200) of the group of electric vehicles, and has a storage capacity of 60 to 80% of the nominal storage capacity.

2. The composite according to claim 1, characterized in that the battery state monitoring system (131, 206) is represented by a control unit and sensors for monitoring the temperature and electrical characteristics of the batteries (130, 205).

3. The composite according to claim 1, characterized in that the group of identical electric vehicles (200) comprises special vehicles or commercial vehicles, electric buses or trolleybuses with extended autonomous driving range, electric freight vehicles equipped with the drive battery (205) and driven by the drive motor, and unmanned autonomous vehicles.

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