Charging and discharging device suitable for electric truck

Abstract

The invention belongs to the field of new energy automobile energy management, and particularly relates to a charging and discharging device suitable for an electric truck. The device comprises a rectifier transformer, a ring main unit, a contactor, at least two bidirectional charging and discharging modules and a single charging and discharging terminal, an input winding of the rectifier transformer is used for accessing a power grid through the ring main unit, and comprises output windings which are respectively connected with different bidirectional charging and discharging modules in the charging and discharging device; each bidirectional charging and discharging module is connected to the same charging and discharging terminal through a contactor; the charging and discharging terminal is used for being connected with the electric truck so as to output or receive electric energy of the electric truck to the electric truck. The ring main unit comprises a wire inlet cabinet, a metering cabinet and a wire outlet cabinet. The metering cabinet is used for metering electric quantity which is obtained from a power grid through the ring main unit and is fed back to the power grid. The charging and discharging efficiency is improved through the architecture that each bidirectional charging and discharging module is matched with a single charging and discharging terminal, stable voltage is provided through the ring main unit, the electric energy interaction efficiency is guaranteed, and meanwhile the power grid is prevented from being impacted.

Description

Technical Field

[0001] This invention belongs to the field of energy management for new energy vehicles, and specifically relates to a charging and discharging device suitable for electric trucks. Background Technology

[0002] The technology related to new energy vehicles is developing rapidly, and electric vehicles are being used more and more widely in various fields. Among them, trucks, especially heavy-duty trucks, are production equipment with characteristics such as heavy loads and frequent short reversals. Therefore, infrastructure that can quickly replenish energy is needed to support the development of electric trucks.

[0003] To ensure the carrying capacity of electric trucks, the battery capacity and voltage level of electric trucks have been significantly improved with the rapid development of battery technology. This has also led to an increasing demand for charging system power. In the current technology, the main energy replenishment facilities for electric trucks are dedicated charging stations. However, dedicated charging stations often have problems such as long charging time and low efficiency. In addition, high-power charging and discharging systems such as dedicated charging stations can easily cause impacts on the power grid, affecting the friendly interaction between electric trucks and the power grid. Summary of the Invention

[0004] The purpose of this invention is to provide a charging and discharging device suitable for electric trucks, which solves the problems of long charging time, low efficiency and easy impact on the power grid in the prior art for electric truck energy replenishment facilities.

[0005] To achieve the above objectives, the present invention provides a charging and discharging device suitable for electric trucks, comprising: a rectifier transformer, a ring main unit, a contactor, at least two bidirectional charging and discharging modules, and a single charging and discharging terminal; the input winding of the rectifier transformer is used to connect to the power grid through the ring main unit, and includes output windings for connecting to different bidirectional charging and discharging modules in the charging and discharging device respectively. Each bidirectional charging and discharging module is connected to the same charging and discharging terminal via a contactor; this charging and discharging terminal is used to connect to the electric truck to output electrical energy to the electric truck or receive electrical energy from the electric truck. A ring main unit includes an incoming line cabinet, a metering cabinet, and an outgoing line cabinet. The metering cabinet is used to measure the amount of electricity obtained from the power grid through the ring main unit and the amount of electricity fed back to the power grid.

[0006] Furthermore, it also includes a prefabricated charging and discharging compartment for arranging the rectifier transformer, ring main unit, contactor, bidirectional charging and discharging module, and charging and discharging terminal in the charging and discharging device.

[0007] Furthermore, the charging and discharging terminal includes two charging and discharging interfaces for energy interaction with electric vehicles, either together or individually.

[0008] Furthermore, auxiliary equipment is also arranged inside the prefabricated charging and discharging compartment; the auxiliary equipment includes lighting, station power distribution, equipment corresponding to the monitoring system, and equipment corresponding to the fire protection system.

[0009] Furthermore, the vehicle connector and charging / discharging cable of the charging / discharging terminal are respectively heat dissipation methods using liquid cooling.

[0010] Furthermore, the rectifier transformer also includes an output winding for connection to auxiliary equipment arranged within the charging and discharging prefabricated compartment.

[0011] Furthermore, the bidirectional charging and discharging module is an IGBT charging and discharging module.

[0012] Furthermore, it also includes a power switching unit for controlling whether the bidirectional charging and discharging module is connected to the charging and discharging terminal, a power control unit for controlling the power flow direction and power switching mode of the bidirectional charging and discharging module, and a charging and discharging control unit for controlling the power flow magnitude of the bidirectional charging and discharging module.

[0013] Furthermore, the IGBT charging and discharging module adopts the AFE technology approach, and the IGBT charging and discharging module includes an end converter for realizing power factor correction.

[0014] The above-described technical solution of the present invention provides a charging and discharging device suitable for electric trucks, the advantages of which include: By using an architecture with at least two bidirectional charging and discharging modules and a single charging and discharging terminal, the electric truck can achieve bidirectional interaction with the power grid while providing higher charging and discharging capabilities, thereby improving charging and discharging efficiency. Furthermore, by connecting the rectifier transformer to the power grid through a ring main unit, stable voltage and accurate metering can be provided, thus ensuring high energy exchange efficiency while avoiding grid impacts and improving the safety of the bidirectional interaction process between the electric truck and the power grid. Attached Figure Description

[0015] Figure 1 This is an example diagram illustrating the structural principle of a charging and discharging device for electric trucks according to an embodiment of the present invention. Figure 2 This is an example diagram showing the specific parameters of the high-voltage power grid connected to the charging and discharging device for electric trucks in an embodiment of the present invention. Figure 3 This is an example diagram of the topology of the bidirectional charging and discharging module in the embodiment of the charging and discharging device of the present invention applicable to electric trucks; Figure 4 This is a structural example diagram of the prefabricated charging and discharging compartment in an embodiment of the charging and discharging device for electric trucks according to the present invention. Detailed Implementation

[0016] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0017] Implementation of a charging and discharging device suitable for electric trucks This embodiment provides a technical solution for a charging and discharging device suitable for electric trucks. The charging and discharging device improves charging and discharging efficiency through the architecture of multiple bidirectional charging and discharging modules and a single charging and discharging terminal. At the same time, it provides stable voltage and accurate metering through a ring network cabinet, thereby ensuring high energy exchange efficiency while avoiding grid impact.

[0018] The charging and discharging device for electric trucks includes: a rectifier transformer, a ring main unit, a contactor, at least two bidirectional charging and discharging modules, and a single charging and discharging terminal; the input winding of the rectifier transformer is used to connect to the power grid through the ring main unit, and includes output windings for connecting to different bidirectional charging and discharging modules in the charging and discharging device respectively. Each bidirectional charging and discharging module is connected to the same charging and discharging terminal via a contactor; this charging and discharging terminal is used to connect to the electric truck to output electrical energy to the electric truck or receive electrical energy from the electric truck. A ring main unit includes an incoming line cabinet, a metering cabinet, and an outgoing line cabinet. The metering cabinet is used to measure the amount of electricity obtained from the power grid through the ring main unit and the amount of electricity fed back to the power grid.

[0019] Therefore, by using an architecture with at least two bidirectional charging and discharging modules and a single charging and discharging terminal, the electric truck and the power grid can achieve bidirectional interaction while providing higher power charging and discharging capabilities, thereby improving charging and discharging efficiency. Furthermore, by connecting the rectifier transformer to the power grid through a ring main unit, stable voltage and accurate metering can be provided, thereby ensuring high energy exchange efficiency while avoiding grid impact and improving the safety of the bidirectional interaction process between the electric truck and the power grid.

[0020] Furthermore, in this embodiment, the charging and discharging device for electric trucks also includes a prefabricated charging and discharging compartment for arranging the rectifier transformer, ring main unit, contactor, bidirectional charging and discharging module, and charging and discharging terminal within the charging and discharging device. Essentially, by using the prefabricated charging and discharging compartment, the various functional components of the charging and discharging device are integrated and arranged, forming a relatively independent charging and discharging environment to reduce external interference, while also saving on the land area and investment costs of the charging and discharging device project.

[0021] To ensure the safety and convenience of the prefabricated charging and discharging compartment, auxiliary equipment is also installed inside. This equipment includes lighting, station power distribution, monitoring system equipment, and fire protection system equipment. With this auxiliary equipment, the prefabricated charging and discharging compartment provides good lighting and auxiliary power distribution, and is equipped with corresponding anomaly detection and alarm functions, meeting fire safety requirements and thus improving the overall protection performance of the station and shortening the construction period.

[0022] In one specific embodiment, a prefabricated charging and discharging compartment is designed as a carrier for charging equipment and auxiliary equipment. The compartment is equipped with four high-power charging and discharging modules (i.e., bidirectional V2G modules), one transformer, one high-voltage incoming cabinet, one high-voltage metering cabinet, one high-voltage outgoing cabinet, one communication control cabinet, and other main equipment. The design and functions of the fire detection and alarm system and fire control equipment within the prefabricated charging and discharging compartment (hereinafter referred to as the prefabricated compartment) comply with the requirements of the current national standard GB / T 50116-2013 "Code for Design of Automatic Fire Alarm Systems" and other relevant standards; the grounding system of the prefabricated compartment complies with the requirements of GB / T 50065-2011 "Code for Grounding Design of AC Electrical Installations" and other relevant standards; the lighting design within the prefabricated compartment complies with the requirements of DL / T 5390-2014 "Technical Regulations for Lighting Design of Power Plants and Prefabricated Substations" and other relevant standards; the prefabricated compartment has good electromagnetic radiation isolation and noise reduction functions, complying with the requirements of GB12348-2008 "Emission Standard for Environmental Noise at the Boundary of Industrial Enterprises" and other relevant standards; the prefabricated compartment complies with the requirements of GB50017-2003 "Code for Structural Design", GB / T17467-2020 "High Voltage / Low Voltage Prefabricated Substations", DL / T537-2018 "High Voltage / Low Voltage Prefabricated Substations" and other standards.

[0023] Furthermore, considering that the outdoor working environment of charging and discharging equipment needs to withstand the effects of environmental hazards such as high and low temperature shocks, gas erosion, dust accumulation, and ultraviolet radiation, the structural protection design of the prefabricated charging and discharging cabin is carried out from two aspects: power module heat dissipation and electrical layout and installation, in order to solve the shortcomings of poor environmental adaptability and high power module failure rate that are common in current direct air-cooled charging and discharging equipment.

[0024] To facilitate the supply of power to auxiliary equipment within the prefabricated charging and discharging compartment, the rectifier transformer also includes an output winding for connecting to the auxiliary equipment located within the compartment. This means that the power supply directly from within the charging and discharging device meets the needs of the auxiliary equipment, saving the cost and space required for an external power source and simplifying the power supply lines.

[0025] A structural example of a charging and discharging device suitable for electric trucks is shown below. Figure 1In a preferred embodiment, the rectifier transformer in this charging and discharging device is a special transformer with a multi-winding design. It provides the required voltage level and power circuit for the bidirectional charging and discharging modules and conventional power consumption, with a capacity of 1250 (4*300+1*50) kVA. Specifically, the secondary side of the rectifier transformer is designed with five windings, four of which have a charging and discharging power of 300kW each, used by different bidirectional charging and discharging modules. The remaining winding has a charging power of 50kW, used for lighting, station power distribution, monitoring systems, fire protection systems, and other necessary auxiliary equipment. Examples of the main parameters of this special transformer are shown in Table 1 below. Table 1

[0026] For ring main units in charging and discharging devices for electric trucks, the high-voltage grid side serves as a 10 kV power source. This ring main unit, via high-voltage incoming cabinet, high-voltage metering cabinet, and high-voltage outgoing cabinet, can be directly connected to the charging and discharging device, thus providing stable power support for the entire device. For specific parameter examples of the high-voltage grid, please refer to [reference needed]. Figure 2 .

[0027] Specifically, the incoming line cabinet, metering cabinet, and outgoing line cabinet work together to ensure stable power supply and accurate metering. In one embodiment, the ring network cabinet uses a high-voltage metering method, with a total metering unit installed within the ring network cabinet. The metering transformer is confirmed by the power supply department. The electricity meter transmits the electricity measurement data to the power grid system or other designated system for processing via wired or wireless communication to achieve electricity metering. In other embodiments, other metering methods may also be used, with the final method determined by the power supply department.

[0028] Furthermore, the charging device supports rapid access to different operation and management platforms and different payment methods, making platform access quick and flexible.

[0029] In this embodiment, the bidirectional charging and discharging module used is an IGBT charging and discharging module. IGBT (Insulated Gate Bipolar Transistor) is a high-efficiency semiconductor device suitable for high-voltage and high-current applications. These IGBT charging and discharging modules provide stable charging power while maintaining high energy conversion efficiency and reducing heat loss, thereby extending the module's lifespan to over 10 years, meeting the requirements of high efficiency, stability, and long lifespan for bidirectional charging and discharging modules. Furthermore, the aforementioned IGBT charging and discharging module adopts the AFE (Advanced Factor Correction) technology route and includes an end-to-end converter for power factor correction (PFC); it can achieve different charging modes such as constant current charging, constant voltage charging, and constant power charging.

[0030] Reference Figure 1In a preferred embodiment, the charging and discharging device for electric trucks is equipped with a total of four bidirectional 250kW charging and discharging modules (i.e., Figure 1 The IGBT charging and discharging module (containing a 250kW bidirectional V2G module) operates in parallel with two modules, capable of outputting two 500kW channels with an output voltage range of DC450V~1000V, enabling charging and discharging devices to achieve a power output of up to 1MW. This design meets the needs of rapid, high-power charging and discharging for single vehicles, significantly improving charging and discharging efficiency. See the example of the IGBT charging and discharging module topology for reference. Figure 3 For specific technical parameters, please refer to Table 2 below: Table 2

[0031] Specifically, the bidirectional charging and discharging module mentioned above, as the core component of the charging and discharging device, has the following functional characteristics: (1) The power factor and harmonic factor can be precisely controlled within the full power range to ensure that they are within the range required by the standard.

[0032] (2) It supports bidirectional energy flow and can be expanded into an integrated photovoltaic, energy storage and charging device to broaden energy sources and application pathways.

[0033] (3) The design is simple and ensures that the secondary winding of the rectifier transformer can be directly connected to the bidirectional charging and discharging module.

[0034] (4) The core module is designed to have a lifespan of more than 10 years, ensuring long-term stable operation.

[0035] (5) The modular design makes the installation and debugging of the bidirectional charging and discharging module more convenient, while reducing maintenance costs and improving the maintainability of the system.

[0036] To achieve charging and discharging control of the bidirectional charging and discharging module, the charging and discharging device for electric trucks also includes a power switching unit for controlling whether the bidirectional charging and discharging module is connected to the charging and discharging terminal, a power control unit for controlling the power flow direction and power switching mode of the bidirectional charging and discharging module, and a charging and discharging control unit for controlling the power flow magnitude of the bidirectional charging and discharging module. This enables information exchange between the various bidirectional charging and discharging modules, allowing for bidirectional energy flow control between the power grid and the electric vehicle, voltage support, etc., improving the efficiency of the charging and discharging system and reducing the overall operating cost of the station. Specifically, the ring main unit, multi-winding rectifier transformer, bidirectional charging and discharging module, output contactor, and charging and discharging terminal are connected to the main power supply in sequence; the multi-winding rectifier transformer is communicatively connected to the bidirectional charging and discharging module and the charging and discharging terminal.

[0037] In this embodiment, the charging and discharging terminal includes two charging and discharging interfaces for energy interaction with electric vehicles, either together or individually. In a preferred embodiment, the charging and discharging interface is in the form of a charging gun, that is, the charging and discharging terminal is a dual-gun type, with a maximum output current of 600A and a maximum output power of 600kW per gun. When both guns charge and discharge the vehicle simultaneously, the maximum power can reach the MW level, which can meet the high-efficiency charging and discharging requirements of electric trucks. For example, a single scan can enable dual-gun charging and discharging of electric trucks, improving the charging and discharging experience.

[0038] Furthermore, the vehicle connector and charging / discharging cable of the charging / discharging terminal utilize liquid cooling for heat dissipation. In other words, to meet the heat dissipation requirements of high-power supercharging terminals, the charging / discharging device for electric trucks has chosen a liquid cooling system as its heat dissipation solution. Compared to traditional natural heat dissipation, the liquid cooling system provides more efficient thermal management capabilities; through circulating coolant, heat is rapidly carried away and transferred to areas away from the charging module for release. This design not only improves heat dissipation efficiency but also reduces the noise level of the equipment during operation.

[0039] In summary, the liquid-cooled charging pile can achieve a maximum charging and discharging current of over 1000A, enabling rapid high-current charging for electric heavy-duty trucks. Furthermore, because the liquid-cooled cable is 30% lighter than conventional charging gun cables, the weight of the charging gun itself is reduced. Additionally, it supports plug-and-charge functionality, enhancing the user experience. The specific technical parameters of this charging and discharging terminal are shown in Table 3 below. Table 3

[0040] In one embodiment, an example of the structure of the prefabricated charging and discharging chamber is as follows: Figure 4 As shown.

[0041] It should be understood that the above-described specific embodiments of the present invention are merely illustrative or explanatory of the principles of the present invention, and do not constitute a limitation thereof.

Claims

1. A charging and discharging device suitable for electric trucks, characterized in that, include: Rectifier transformer, ring main unit, contactor, at least two bidirectional charging / discharging modules and a single charging / discharging terminal; The input winding of the rectifier transformer is used to connect to the power grid through a ring main unit, and includes output windings for connecting to different bidirectional charging and discharging modules in the charging and discharging device respectively. Each bidirectional charging and discharging module is connected to the same charging and discharging terminal via a contactor; this charging and discharging terminal is used to connect to the electric truck to output electrical energy to the electric truck or receive electrical energy from the electric truck. A ring main unit includes an incoming line cabinet, a metering cabinet, and an outgoing line cabinet. The metering cabinet is used to measure the amount of electricity obtained from the power grid through the ring main unit and the amount of electricity fed back to the power grid.

2. The charging and discharging device for electric trucks according to claim 1, characterized in that, It also includes a prefabricated charging and discharging compartment, which is used to house the rectifier transformer, ring main unit, contactor, bidirectional charging and discharging module and charging and discharging terminal in the charging and discharging device.

3. The charging and discharging device for electric trucks according to claim 1 or 2, characterized in that, The charging and discharging terminal includes two charging and discharging interfaces for energy exchange with electric vehicles, either together or individually.

4. The charging and discharging device for electric trucks according to claim 2, characterized in that, The prefabricated charging and discharging compartment is also equipped with auxiliary equipment, including lighting, station power distribution, monitoring system equipment, and fire protection system equipment.

5. The charging and discharging device for electric trucks according to claim 1 or 2, characterized in that, The vehicle connector and charging / discharging cable of the charging / discharging terminal are respectively heat dissipation methods using liquid cooling.

6. The charging and discharging device for electric trucks according to claim 4, characterized in that, The rectifier transformer also includes an output winding for connection to auxiliary equipment arranged within the charging and discharging prefabricated compartment.

7. The charging and discharging device for electric trucks according to claim 1 or 2, characterized in that, The bidirectional charge / discharge module is an IGBT charge / discharge module.

8. The charging and discharging device for electric trucks according to claim 1 or 2, characterized in that, It also includes a power switching unit for controlling whether the bidirectional charging and discharging module is connected to the charging and discharging terminal, a power control unit for controlling the power flow direction and power switching mode of the bidirectional charging and discharging module, and a charging and discharging control unit for controlling the power flow magnitude of the bidirectional charging and discharging module.

9. The charging and discharging device for electric trucks according to claim 7, characterized in that, The IGBT charging and discharging module adopts the AFE technology approach and includes an end converter for power factor correction.

Images