A charging pile system and a control method

Abstract

The application discloses a charging pile system and a control method, and the system comprises a first bidirectional module, a second bidirectional module, a unidirectional module and a controller; the first bidirectional module and the second bidirectional module each comprise at least one bidirectional AC / DC module, one end of all the bidirectional AC / DC modules of the first bidirectional module and the second bidirectional module is connected with a first alternating current power branch, the other end of all the bidirectional AC / DC modules of the first bidirectional module and the other end of all the bidirectional AC / DC modules of the second bidirectional module is connected with a first connecting line and a second connecting line respectively; the unidirectional module comprises at least one unidirectional AC / DC module, one end of all the unidirectional AC / DC modules is connected with a second alternating current power branch, and the other end of all the unidirectional AC / DC modules is connected with a third connecting line; controllable switches are arranged between the first connecting line and the second connecting line, between the first connecting line and a first charging gun, between the second connecting line and a second charging gun, between the third connecting line and the first charging gun and between the third connecting line and the second charging gun; and the controller controls the controllable switches to switch the working conditions of single-gun charging, single-gun discharging, double-gun charging, double-gun discharging and parallel charging and discharging. The application adopts a mixed structure of bidirectional AC / DC modules and unidirectional AC / DC modules, the unit price of the unidirectional AC / DC module is one third of the unit price of the bidirectional AC / DC module, and the hardware cost is greatly reduced.

Description

Technical Field

[0001] This invention relates to a charging pile system and control method, specifically to a charging pile system and charging / discharging control method that supports vehicle-to-grid (V2G) functionality, belonging to the field of charging pile technology. Background Technology

[0002] V2G charging piles enable bidirectional energy exchange between the power grid and electric vehicle batteries. They can charge vehicles and also feed energy back to the grid, participating in ancillary services such as peak shaving and frequency regulation. Currently, most dual-gun V2G charging piles on the market use a fully bidirectional AC / DC module configuration. This configuration has the following drawbacks: taking a 120kW dual-gun charging pile as an example, it requires four 30kW bidirectional AC / DC modules, resulting in high hardware costs. Summary of the Invention

[0003] This invention provides a charging pile system and control method, which solves the problems disclosed in the background art.

[0004] According to one aspect of this application, a charging pile system is provided, including a first bidirectional module, a second bidirectional module, a unidirectional module, and a controller; The first bidirectional module and the second bidirectional module each include at least one bidirectional AC / DC module. One end of all the bidirectional AC / DC modules of the first bidirectional module and the second bidirectional module are connected to the first AC power branch. The other end of all the bidirectional AC / DC modules of the first bidirectional module and the other end of all the bidirectional AC / DC modules of the second bidirectional module are respectively connected to the first connection line and the second connection line. The unidirectional module includes at least one unidirectional AC / DC module, one end of all unidirectional AC / DC modules is connected to the second AC power branch, and the other end of all unidirectional AC / DC modules is connected to the third connection line. Controllable switches are installed between the first and second connecting lines, between the first connecting line and the first charging gun, between the second connecting line and the second charging gun, between the third connecting line and the first charging gun, and between the third connecting line and the second charging gun. The controller controls the controllable switches to switch between single-gun charging, single-gun discharging, dual-gun charging, dual-gun discharging, and parallel charging and discharging modes.

[0005] Furthermore, the first AC power branch and the second AC power branch are independent branches and do not share power.

[0006] Furthermore, the first AC power branch and the second AC power branch have the same structure, both including a molded case circuit breaker and an AC contactor connected in series. The molded case circuit breaker is connected to the external power grid, and the AC contactor is connected to the AC / DC module.

[0007] Furthermore, the ratio of bidirectional AC / DC modules to unidirectional AC / DC modules in the system is adjusted according to charging and discharging requirements; if the charging requirement is high, the proportion of unidirectional AC / DC modules is increased; if the discharging requirement is high, the proportion of bidirectional AC / DC modules is increased.

[0008] Furthermore, the controllable switch is a DC contactor.

[0009] According to another aspect of this application, a control method for a charging pile system is provided, comprising: In response to the detection that the Nth charging gun is ready to charge and another charging gun is idle, the controllable switch between the Nth charging gun and the third connection line and between the Nth charging gun and the Nth connection line is closed, and the unidirectional module or the bidirectional module connected to the unidirectional module and the Nth connection line is invoked for charging; wherein, the Nth charging gun is the target charging gun, and N is one or two; In response to detecting that the Nth charging gun is ready to charge and another charging gun is in a charging state, the controllable switch between the other charging gun and the connected bidirectional module is opened, and the controllable switches between the first connection line and the second connection line and between the Nth charging gun and the Nth connection line are closed, and the bidirectional module connected to the Nth connection line or the first bidirectional module and the second bidirectional module are called to charge. In response to the detection that the Nth charging gun is ready to charge and another charging gun is in a discharging state, the controllable switch between the Nth charging gun and the third connection line is closed, and the unidirectional module is called to charge. In response to the detection that the Nth charging gun is ready to discharge and the other charging gun is idle, the controllable switch between the first connection line and the second connection line and between the Nth charging gun and the Nth connection line is closed, and the first bidirectional module and the second bidirectional module are called to discharge. In response to detecting that the Nth charging gun is ready to discharge and another charging gun is in a charging state, the controllable switch between the other charging gun and the connected bidirectional module is opened, and the controllable switches between the first connection line and the second connection line and between the Nth charging gun and the Nth connection line are closed, and the first bidirectional module and the second bidirectional module are called to discharge. In response to the detection that the Nth charging gun is about to discharge and another charging gun is in a discharging state, the controllable switch between the first connection line and the second connection line is opened, the controllable switch between the Nth charging gun and the Nth connection line is closed, and the bidirectional module connected to the Nth connection line is called to discharge.

[0010] Furthermore, during charging, if the vehicle's power demand exceeds the total power of a single power supply module, both modules will be used to supply power together.

[0011] Furthermore, the control method also includes disconnecting all controllable switches between the faulty bidirectional AC / DC module and the charging gun in response to detecting a bidirectional AC / DC module fault in any bidirectional module.

[0012] The beneficial effects achieved by this invention are as follows: 1. This invention adopts a hybrid structure of bidirectional AC / DC modules and unidirectional AC / DC modules. The unit price of the unidirectional AC / DC module is one-third of that of the bidirectional AC / DC module, which significantly reduces hardware costs. 2. The ratio of bidirectional AC / DC modules to unidirectional AC / DC modules in this invention can be adjusted according to charging and discharging requirements. Compared with the fixed hardware configuration of the bidirectional AC / DC module solution, this allows for flexible adjustment and avoids waste of hardware resources. 3. The basic charging load of this invention is borne by the unidirectional AC / DC module. The bidirectional AC / DC module only operates during high-power charging and V2G discharging, which significantly reduces the operating time and mode switching frequency of the bidirectional AC / DC module and can reduce the overall failure rate. 4. In the event of a failure of the bidirectional AC / DC module, the unidirectional AC / DC module can still independently provide complete charging services, with only the discharging function being limited. This avoids the paralysis of the entire charging station due to the failure of a single AC / DC module and ensures the basic operational revenue of the site. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the resulting charging pile system; Figure 2 A schematic diagram of the control logic when charging the target charging gun; Figure 3 A schematic diagram of the control logic when discharging the target charging gun. Detailed Implementation

[0014] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit this application or its application or use. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0015] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps described in these embodiments do not limit the scope of this application.

[0016] At the same time, it should be understood that, for ease of description, the dimensions of the various parts shown in the accompanying drawings are not drawn according to actual scale.

[0017] Techniques, methods, and equipment known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and equipment should be considered part of the specification.

[0018] In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values.

[0019] It should be noted that similar symbols and letters in the accompanying drawings represent similar items; therefore, once an item is defined in one accompanying drawing, it does not need to be discussed further in subsequent accompanying drawings.

[0020] Furthermore, in the description of the embodiments of this application, the terms "first," "second," etc., are used only for distinguishing descriptions and should not be construed as indicating or implying relative importance. Therefore, features defined with "first" or "second" may explicitly or implicitly include one or more features.

[0021] This application provides a charging pile system, which may include at least a first bidirectional module, a second bidirectional module, a unidirectional module, and a controller.

[0022] Both the first and second bidirectional modules include at least one bidirectional AC / DC module. One end of all bidirectional AC / DC modules in both modules is connected to a first AC power branch. The other ends of all bidirectional AC / DC modules in the first and second modules are respectively connected to a first connection line and a second connection line. Each unidirectional module includes at least one unidirectional AC / DC module. One end of all unidirectional AC / DC modules is connected to a second AC power branch, and the other end is connected to a third connection line. Controllable switches are provided between the first and second connection lines, between the first and first charging guns, between the second and second charging guns, between the third and first charging guns, and between the third and second charging guns. The controller controls these controllable switches to switch between single-gun charging, single-gun discharging, dual-gun charging, dual-gun discharging, and parallel charging / discharging modes.

[0023] It should be noted that the number of AC / DC modules in the first bidirectional module, the second bidirectional module, and the unidirectional module needs to be determined according to the actual situation. For example, a 120kW dual-gun charging pile can be configured with two 30kW bidirectional AC / DC modules and two 30kW unidirectional AC / DC modules. In this case, the first bidirectional module and the second bidirectional module each contain one AC / DC module, and the unidirectional module contains two 30kW unidirectional AC / DC modules.

[0024] The system described above employs a hybrid structure of bidirectional and unidirectional AC / DC modules. The unit price of a unidirectional AC / DC module is one-third that of a bidirectional AC / DC module, significantly reducing hardware costs. Taking a 120kW dual-gun charging pile as an example, the traditional method requires four bidirectional AC / DC modules, while the system described above only requires two bidirectional AC / DC modules and two unidirectional AC / DC modules, resulting in a substantial cost reduction.

[0025] In some embodiments, the first AC power branch and the second AC power branch are independent branches and do not share power, i.e., AC-side dual power pool isolation, which can avoid harmonic interference and circulating current problems between different types of modules.

[0026] The specific structures of the first and second AC power branches are the same, both including a molded case circuit breaker and an AC contactor connected in series. The molded case circuit breaker is connected to the external power grid, and the AC contactor is connected to the AC / DC module.

[0027] It should be noted that the aforementioned controllable switch can be a DC contactor, or other existing controllable devices.

[0028] In some embodiments, the ratio of bidirectional AC / DC modules to unidirectional AC / DC modules in the system is adjusted according to charging and discharging requirements; if the charging requirement is high, the proportion of unidirectional AC / DC modules is increased; if the discharging requirement is high, the proportion of bidirectional AC / DC modules is increased.

[0029] Taking a 160kW dual-gun charging pile as an example, the traditional solution requires six 30kW bidirectional AC / DC modules. Here, a flexible configuration can be made according to the needs of the site as follows: For charging-focused stations: 4 units of 30kW unidirectional AC / DC modules and 2 units of 30kW bidirectional AC / DC modules are configured, with a total power of 180kW, meeting the needs of high-frequency charging while retaining V2G discharge capability. The cost is significantly lower than that of the fully bidirectional solution. For discharging-focused stations: 2 units of 30kW unidirectional AC / DC modules and 4 units of 30kW bidirectional AC / DC modules are configured to enhance discharge power while retaining unidirectional AC / DC modules to handle basic charging load and reduce losses in bidirectional AC / DC modules.

[0030] The number of bidirectional AC / DC modules and unidirectional AC / DC modules in the system can be flexibly adjusted according to the actual charging and discharging demand ratio of the site. Sites with a primary demand for charging can increase the proportion of unidirectional AC / DC modules, while sites with a primary demand for discharging can increase the proportion of bidirectional AC / DC modules, thus avoiding waste of hardware resources.

[0031] The above system can be found in [reference]. Figure 1 , Figure 1 A specific example is given. Figure 1 In the first AC power branch, there are two series of molded case circuit breakers QF1 and AC contactors KM1, which supply power to all bidirectional AC / DC modules. The second AC power branch includes two series of molded case circuit breakers QF2 and AC contactors KM2, which supply power to all unidirectional AC / DC modules. Each of the first and second bidirectional modules contains one AC / DC module, and each unidirectional module is also a unidirectional AC / DC module.

[0032] All DC contactors form a ring-tangential topology, where C1 is the DC contactor between the first and second connection lines, C2 is the DC contactor between the first connection line and the first charging gun, C3 is the DC contactor between the second connection line and the second charging gun, C4 is the DC contactor between the third connection line and the first charging gun, and C5 is the DC contactor between the third connection line and the second charging gun. The control terminals of all DC contactors are connected to a controller. Through the on / off combinations of the DC contactors, various connection methods between the AC / DC module and the dual charging guns can be achieved. The first charging gun (i.e....) Figure 1 Gun A in the middle) and the second charging gun (i.e. Figure 1 The B gun in the diagram consists of two DC charging guns used to connect to the electric vehicle. The controller communicates with all DC contactors, AC / DC modules, and charging guns to perform status monitoring and control.

[0033] Based on the above system, this application also relates to a control method for the above charging pile system. The method is implemented in a controller and may include at least the following steps: A. In response to detecting that the Nth charging gun is ready to charge and another charging gun is idle, control the controllable switch between the Nth charging gun and the third connection line and between the Nth charging gun and the Nth connection line to close, and call the unidirectional module or the bidirectional module connected to the unidirectional module and the Nth connection line to charge; wherein, the Nth charging gun is the target charging gun, and N is one or two.

[0034] B. In response to detecting that the Nth charging gun is ready to charge and another charging gun is in a charging state, control the controllable switch between the other charging gun and the connected bidirectional module to be disconnected, control the controllable switch between the first connection line and the second connection line and between the Nth charging gun and the Nth connection line to be closed, and call the bidirectional module connected to the Nth connection line or the first bidirectional module and the second bidirectional module to charge.

[0035] C. In response to detecting that the Nth charging gun is ready to charge and another charging gun is in a discharging state, control the controllable switch between the Nth charging gun and the third connection line to close, and call the unidirectional module to charge.

[0036] D. In response to detecting that the Nth charging gun is ready to discharge and the other charging gun is idle, control the controllable switch between the first connection line and the second connection line and between the Nth charging gun and the Nth connection line to close, and call the first bidirectional module and the second bidirectional module to discharge.

[0037] E. In response to detecting that the Nth charging gun is ready to discharge and another charging gun is in a charging state, control the controllable switch between the other charging gun and the connected bidirectional module to be disconnected, control the controllable switch between the first connection line and the second connection line and between the Nth charging gun and the Nth connection line to be closed, and call the first bidirectional module and the second bidirectional module to discharge.

[0038] F. In response to detecting that the Nth charging gun is about to discharge and another charging gun is in a discharging state, the controllable switch between the first connection line and the second connection line is opened, the controllable switch between the Nth charging gun and the Nth connection line is closed, and the bidirectional module connected to the Nth connection line is called to discharge.

[0039] In some embodiments, if the vehicle's power demand exceeds the total power of a single power supply module during charging, both modules are used to supply power together. It can be seen that the basic charging load is borne by the unidirectional AC / DC module, while the bidirectional AC / DC module only operates during high-power charging and V2G discharging. This significantly reduces the operating time and mode switching frequency of the bidirectional AC / DC module, thereby reducing the overall failure rate by approximately one-third.

[0040] by Figure 1 Taking the structure as an example, the above method can be found in [reference needed]. Figure 2 and Figure 3 Assuming the target charging gun is the first charging gun, the controller detects that the first charging gun is unlocked and ready to charge. Then, it further detects the status of the second charging gun. If the second charging gun is idle, when the electric vehicle is detected to be connected to the first charging gun, C2 and C4 are closed, and the unidirectional AC / DC module is activated first to charge the first charging gun. When the power demand of the electric vehicle exceeds the total power of the unidirectional AC / DC module, the left bidirectional AC / DC module is activated to provide power, thereby expanding the power capacity. If the second charging gun is in a charging state (i.e., charging), when the electric vehicle is detected to be connected to the first charging gun, C3 is disconnected, and C1 and C2 are closed. The left bidirectional AC / DC module is activated first to provide power to the first charging gun. When the power demand of the electric vehicle exceeds the total power of the left bidirectional AC / DC module, the right bidirectional AC / DC module is activated to provide power, thereby enabling simultaneous charging of both guns. If the second charging gun is in a discharging state, when the electric vehicle is detected to be connected to the first charging gun, only C4 is closed, and the unidirectional AC / DC module independently charges the first charging gun, completely isolated from the discharge path of the second charging gun, without interference, thus achieving parallel charging and discharging.

[0041] Similarly, assuming the target charging gun is the first charging gun, the controller detects that the first charging gun is unlocked and ready to discharge. Then, it further detects the status of the second charging gun. If the second charging gun is idle, when the electric vehicle is detected to be connected to the first charging gun, C2 and C1 are closed, and the left and right bidirectional AC / DC modules are activated in sequence to discharge the first charging gun together, outputting the maximum discharge power. If the second charging gun is charging, when the electric vehicle is detected to be connected to the first charging gun, C3 is disconnected, and C1 and C2 are closed, calling the left and right bidirectional AC / DC modules to discharge the first charging gun together. The second charging gun is independently powered by the unidirectional AC / DC module, and charging and discharging operate simultaneously. If the second charging gun is discharging, when the electric vehicle is detected to be connected to the first charging gun, C1 and C2 are disconnected, and the left bidirectional AC / DC module is activated to discharge the first charging gun independently. The right bidirectional AC / DC module discharges the second charging gun independently, achieving simultaneous discharge of both guns.

[0042] In some embodiments, in response to detecting a bidirectional AC / DC module failure in any bidirectional module, all controllable switches between the faulty bidirectional module and the charging gun are disconnected. Due to the hybrid structure of bidirectional and unidirectional AC / DC modules, even in the event of a bidirectional AC / DC module failure, the unidirectional AC / DC module can still independently provide complete charging services, with only its discharge function limited. This avoids a single module failure causing the entire charging gun to fail, thus ensuring the basic operational revenue of the charging station.

[0043] by Figure 1 For example, when one of the bidirectional AC / DC modules fails, the controller detects the fault signal and immediately disconnects the corresponding DC contactor, taking the module out of operation. At this time, the remaining bidirectional AC / DC module and the unidirectional module can still operate normally. The unidirectional AC / DC module can independently provide basic charging power, while the remaining bidirectional AC / DC module can participate in capacity expansion. The charging function is completely unaffected, and the discharging power is halved, but V2G service can still be provided normally, preventing the entire charging station from failing and ensuring continuous operation of the site.

[0044] The above description is only a preferred embodiment of this application. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of this application, and these improvements and modifications should also be considered within the scope of protection of this application.

Claims

1. A charging pile system, characterized in that, It includes a first bidirectional module, a second bidirectional module, a unidirectional module, and a controller; The first bidirectional module and the second bidirectional module each include at least one bidirectional AC / DC module. One end of all the bidirectional AC / DC modules of the first bidirectional module and the second bidirectional module are connected to the first AC power branch. The other end of all the bidirectional AC / DC modules of the first bidirectional module and the other end of all the bidirectional AC / DC modules of the second bidirectional module are respectively connected to the first connection line and the second connection line. The unidirectional module includes at least one unidirectional AC / DC module, one end of all unidirectional AC / DC modules is connected to the second AC power branch, and the other end of all unidirectional AC / DC modules is connected to the third connection line. Controllable switches are installed between the first and second connecting lines, between the first connecting line and the first charging gun, between the second connecting line and the second charging gun, between the third connecting line and the first charging gun, and between the third connecting line and the second charging gun. The controller controls the controllable switches to switch between single-gun charging, single-gun discharging, dual-gun charging, dual-gun discharging, and parallel charging and discharging modes.

2. The system according to claim 1, characterized in that, The first AC power branch and the second AC power branch are independent branches and do not share power.

3. The system according to claim 2, characterized in that, The first AC power branch and the second AC power branch have the same structure, both including a molded case circuit breaker and an AC contactor connected in series. The molded case circuit breaker is connected to the external power grid, and the AC contactor is connected to the AC / DC module.

4. The system according to claim 1, characterized in that, The ratio of bidirectional AC / DC modules to unidirectional AC / DC modules in the system is adjusted according to charging and discharging requirements; if the charging requirement is high, the proportion of unidirectional AC / DC modules is increased; if the discharging requirement is high, the proportion of bidirectional AC / DC modules is increased.

5. The system according to claim 1, characterized in that, The controllable switch is a DC contactor.

6. A control method for a charging pile system, characterized in that, The system is the system according to any one of claims 1 to 5, and the control method includes: In response to the detection that the Nth charging gun is ready to charge and another charging gun is idle, the controllable switch between the Nth charging gun and the third connection line and between the Nth charging gun and the Nth connection line is closed, and the unidirectional module or the bidirectional module connected to the unidirectional module and the Nth connection line is invoked for charging; wherein, the Nth charging gun is the target charging gun, and N is one or two; In response to detecting that the Nth charging gun is ready to charge and another charging gun is in a charging state, the controllable switch between the other charging gun and the connected bidirectional module is opened, and the controllable switches between the first connection line and the second connection line and between the Nth charging gun and the Nth connection line are closed, and the bidirectional module connected to the Nth connection line or the first bidirectional module and the second bidirectional module are called to charge. In response to the detection that the Nth charging gun is ready to charge and another charging gun is in a discharging state, the controllable switch between the Nth charging gun and the third connection line is closed, and the unidirectional module is called to charge. In response to the detection that the Nth charging gun is ready to discharge and the other charging gun is idle, the controllable switch between the first connection line and the second connection line and between the Nth charging gun and the Nth connection line is closed, and the first bidirectional module and the second bidirectional module are called to discharge. In response to detecting that the Nth charging gun is ready to discharge and another charging gun is in a charging state, the controllable switch between the other charging gun and the connected bidirectional module is opened, and the controllable switches between the first connection line and the second connection line and between the Nth charging gun and the Nth connection line are closed, and the first bidirectional module and the second bidirectional module are called to discharge. In response to the detection that the Nth charging gun is about to discharge and another charging gun is in a discharging state, the controllable switch between the first connection line and the second connection line is opened, the controllable switch between the Nth charging gun and the Nth connection line is closed, and the bidirectional module connected to the Nth connection line is called to discharge.

7. The method according to claim 6, characterized in that, During charging, if the vehicle's power demand exceeds the total power of a single power supply module, both modules will be used to supply power together.

8. The method according to claim 6, characterized in that, The control method further includes, in response to detecting a bidirectional AC / DC module fault in any bidirectional module, disconnecting all controllable switches between the faulty bidirectional module and the charging gun.

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