Charging circuit structure, charging pile and power supply system for vehicle-mounted charger

Abstract

The utility model provides a charging circuit structure, a charging pile and a power supply system for a vehicle-mounted charger, and the charging circuit structure comprises an input module which provides a to-be-processed power supply voltage; the voltage transformation and rectification module is connected with the input module and is used for carrying out voltage transformation and rectification on the power supply voltage and outputting first direct current voltage; and the direct current conversion module is connected with the voltage transformation and rectification module and converts the first direct current voltage into second direct current voltage directly used for vehicle-mounted charging. According to the invention, the cable is reselected according to the first DC voltage level of the transformation output to replace a 220V AC cable, and the cost of the required cable is effectively reduced under the same voltage drop and transmission distance.

Description

Technical Field

[0001] The present application belongs to the technical field of charging design, and relates to a charging circuit, and in particular to a charging circuit structure, a charging pile, and a power supply system for an on-board charger. Background Art

[0002] At present, with the popularization of electric vehicles and the construction of charging infrastructure, on-board chargers have become an indispensable device in the daily life of electric vehicle users. On-board chargers refer to chargers fixedly installed on electric vehicles, which have the ability to safely and automatically charge the power batteries of electric vehicles. The chargers can dynamically adjust the charging current or voltage parameters based on the data provided by the battery management system (BMS), perform corresponding actions, and complete the charging process.

[0003] In daily life, when using an AC 220V powered on-board charger to charge electric vehicles, the charging power is relatively high compared to the power supply voltage. When the power supply is far away from the charging pile, the cost of the power supply cable is too high, even far higher than the price of the charging pile itself. Summary of the invention

[0004] The present application provides a charging circuit structure, a charging pile and a power supply system for a vehicle-mounted charger, which are used to solve the problem of high cost of power supply cables.

[0005] In a first aspect, the present application provides a charging circuit structure, which includes: an input module, which provides a power supply voltage to be processed; a transformer and rectifier module, which is connected to the input module, transforms and rectifies the power supply voltage, and outputs a first DC voltage; and a DC conversion module, which is connected to the transformer and rectifier module, and converts the first DC voltage into a second DC voltage directly used for on-board charging.

[0006] In an implementation of the first aspect, the input module includes a 10 kV AC power supply system; the 10 kV AC power supply system is electrically connected to the transformer and rectifier module through three phases.

[0007] In an implementation of the first aspect, the input module includes a 10kV AC power supply system and a 380V AC power supply system; the 380V AC power supply system is electrically connected to the transformer and rectifier module via three phases.

[0008] In an implementation of the first aspect, the charging circuit structure further includes: a step-down transformer module; an input end of the step-down transformer module is connected to the 10kV AC power supply system, and an output end is connected to the 380V AC power supply system.

[0009] In an implementation of the first aspect, the DC conversion module is arranged in the charging pile, and the charging line structure also includes: a cable laid from the transformer and rectifier module to each charging pile of the charging station; one end of the cable is connected to the transformer and rectifier module, and the other end is connected to the DC conversion module of each charging pile; the cable is used to transmit the first DC voltage from the transformer and rectifier module to each charging pile of the charging station.

[0010] In an implementation manner of the first aspect, the first DC voltage is a DC voltage value within a range of 700V-900V.

[0011] In an implementation manner of the first aspect, the second DC voltage is 320V.

[0012] In a second aspect, the present application provides a charging pile, and the charging pile includes: the charging circuit structure described above.

[0013] In a third aspect, the present application provides a power supply system for a vehicle-mounted charger, the power supply system for the vehicle-mounted charger comprising: the charging pile and the vehicle-mounted charger of the electric vehicle; the charging pile and the vehicle-mounted charger are electrically connected via the charging port of the electric vehicle; the charging pile outputs 320V DC power to the charging port of the electric vehicle to charge the vehicle-mounted charger of the electric vehicle.

[0014] In an implementation of the third aspect, the on-board charger includes: a filter, a PFC circuit, a first capacitor, a DC transformer module, a second capacitor and a battery; the filter receives the 320V DC power output by the charging pile, and charges the battery through the PFC circuit, the first capacitor, the DC transformer module, and the second capacitor.

[0015] As described above, the charging circuit structure, charging pile and power supply system for the vehicle charger described in the present application have the following beneficial effects:

[0016] The present application provides a charging circuit structure, including: an input module, a transformer and rectifier module and a DC conversion module. The input module provides a power supply voltage to be processed; the transformer and rectifier module is connected to the input module, transforms and rectifies the power supply voltage, and outputs a first DC voltage; the DC conversion module is connected to the transformer and rectifier module, and converts the first DC voltage into a second DC voltage directly used for vehicle charging. The present application reselects cables according to the first DC voltage level of the transformer output to replace 220V AC cables, effectively reducing the construction cost of the required power cables under the same voltage drop and transmission distance. Furthermore, through 800V high-voltage DC power supply, the cross-sectional area of ​​the power cables laid under the voltage drop specified by the national standard is greatly reduced, and the cable cost and the total equipment cost are greatly reduced. The cost of 800V DC cable can be reduced to about 10% of the cable required for 220V AC power supply. Even if a centralized multi-pulse transformer rectifier is added and each charging pile is modified, in charging stations with a large number of charging piles and a long distance from the power supply, this application can still reduce the total cost of electrical equipment to less than 50% of 220V AC power supply. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 Shown is a structural connection diagram of the charging circuit structure described in an embodiment of the present application.

[0018] Figure 2 Shown is a transformer and rectifier circuit structure diagram of the charging circuit structure described in an embodiment of the present application.

[0019] Figure 3 Shown is another transformer and rectifier circuit structure diagram of the charging circuit structure described in an embodiment of the present application.

[0020] Figure 4 Shown is a schematic diagram of the structural connection of a power supply system for an on-board charger according to an embodiment of the present application.

[0021] Figure 5 Shown is a circuit structure diagram of a power supply system for a vehicle-mounted charger as described in an embodiment of the present application.

[0022] Figure 6 Shown is an electrical architecture diagram of an on-board charger of a power supply system for an on-board charger according to an embodiment of the present application.

[0023] Figure 7 Shown is an electrical diagram of a PFC circuit of a power supply system for a vehicle charger according to an embodiment of the present application.

[0024] Component number description

[0025] 1 Charging circuit structure

[0026] 11 Input Module

[0027] 12 Transformer and rectifier modules

[0028] 13 DC conversion module

[0029] 2. Electric Vehicles DETAILED DESCRIPTION

[0030] The following describes the embodiments of the present application through specific examples, and those skilled in the art can easily understand other advantages and effects of the present application from the contents disclosed in this specification. The present application can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present application. It should be noted that the following embodiments and features in the embodiments can be combined with each other without conflict.

[0031] It should be noted that the illustrations provided in the following embodiments are only used to illustrate the basic concept of the present application in a schematic manner, and therefore the illustrations only show components related to the present application rather than being drawn according to the number, shape and size of components in actual implementation. In actual implementation, the type, quantity and proportion of each component may be changed arbitrarily, and the component layout may also be more complicated.

[0032] The technical solutions in the embodiments of the present application will be described in detail below in conjunction with the drawings in the embodiments of the present application.

[0033] See also Figure 1 , which is a schematic diagram showing the structural connection of the charging circuit structure described in the embodiment of the present application. Figure 1 As shown, this embodiment provides a charging circuit structure 1, which specifically includes: an input module 11, a transformer and rectifier module 12 and a DC conversion module 13.

[0034] The input module 11 provides a supply voltage to be processed.

[0035] The transformer and rectifier module 12 is connected to the input module 11 , and performs transformer and rectification on the supply voltage to output a first DC voltage.

[0036] The DC conversion module 13 is connected to the transformer and rectifier module 12 to convert the first DC voltage into a second DC voltage directly used for on-board charging.

[0037] In one embodiment, the input module includes a 10kV AC power supply system.

[0038] The 10kV AC power supply system is electrically connected to the transformer and rectifier module via three phases. Specifically, the transformer and rectifier module includes a transformer and rectifier.

[0039] See also Figure 2 , which shows a transformer rectifier circuit structure diagram of the charging circuit structure described in the embodiment of the present application. Figure 2 As shown, the 10kV AC (power supply) system is connected to the transformer rectifier through three-phase electricity A, B, and C, and outputs 800V DC through the transformer rectifier. The 800V DC is transmitted to the charging pile of the electric vehicle through subsequent cable laying.

[0040] In another embodiment, the input module includes a 10kV AC power supply system and a 380V AC power supply system.

[0041] The 380V AC power supply system is electrically connected to the transformer and rectifier module via three phases. Specifically, the transformer and rectifier module includes a transformer and rectifier.

[0042] Furthermore, the charging circuit structure also includes: a step-down transformer module.

[0043] The input end of the step-down transformer module is connected to the 10kV AC power supply system, and the output end is connected to the 380V AC power supply system. Specifically, the step-down transformer module includes a step-down transformer that reduces voltage from 10kV to 380V.

[0044] See also Figure 3 , which shows another transformer rectifier circuit structure diagram of the charging circuit structure described in the embodiment of the present application. Figure 3 As shown, the 10kV AC (power supply) system is connected to a step-down transformer that reduces 10kV to 380V through three-phase electricity A, B, and C. The step-down transformer outputs 380V AC three-phase electricity A, B, and C to the transformer-rectifier, and outputs 800V DC through the transformer-rectifier. The 800V DC is transmitted to the charging pile of the electric vehicle through subsequent cable laying.

[0045] exist Figure 2 and Figure 3 In the embodiment of the invention, the transformer rectifier can be a multi-pulse transformer rectifier. In the specific implementation, the optimal solution is to use the 10kV AC distribution network voltage as input and directly generate 800V DC voltage after the transformer rectifier, which can save a conventional 10kV / 380V distribution transformer. Figure 2 As shown; if there is no 10kV access condition, you can take the next best option and use 380V industrial power voltage as input, and generate 800V DC voltage after transformer rectifier, as shown Figure 3 As shown. Figure 2 and Figure 3 Obviously, the difference lies in Figure 2 Compare Figure 3A 10kV / 380V transformer is saved, but an extra voltage conversion link is added, resulting in a slight increase in power loss compared to the 10kV solution. However, the overall effect is basically the same.

[0046] In one embodiment, the DC conversion module is disposed in a charging pile, and the charging line structure further comprises: a cable laid from the transformer and rectifier module to each charging pile of the charging station.

[0047] One end of the cable is connected to the transformer and rectifier module, and the other end is connected to the DC conversion module of each charging pile; the cable is used to transmit the first DC voltage from the transformer and rectifier module to each charging pile of the charging station.

[0048] In one embodiment, the first DC voltage is a DC voltage value in the range of 700V-900V.

[0049] Specifically, the first DC voltage is 800V, and the traditional 220V AC power supply cable is replaced by an 800V DC cable. Under the same voltage drop and transmission distance, the cable cost required for the 800V voltage level is only less than 10% of that under the 220V voltage. Correspondingly, the original 220V input charging pile is changed to a charging pile with 800V DC as input and 320V DC as output. This application further improves the effect of the implementation of this solution by reducing the scope of modification to the pile to a minimum.

[0050] In one embodiment, the second DC voltage is 320 V. It should be noted that 320 V is not an absolute fixed value, and the voltage fluctuation range may be 320 V + / - 1%.

[0051] This application adopts 320V mainly to meet the voltage requirement range of the on-board charger and adapt to more on-board chargers. At this voltage, the charging efficiency is high, the compatibility with the on-board charger is better, and it is more conducive to charging. If other voltage values ​​are used, the on-board charger may not work, the charging efficiency is low, and there are other safety hazards. In addition, this application considers the voltage range of the on-board charger. The design voltage range of the on-board charger is the range of the ordinary 220V AC voltage. The internal working principle is to rectify the 220V AC voltage and then transform it for use in the internal circuit of the charger. In order to provide both DC voltage and compatibility with the charger circuit, the DC voltage is set at 320V, which is the peak value of the 220V AC voltage, and it is also the voltage value after the AC voltage is rectified. Since AC chargers often allow a + / -15% deviation from the nominal voltage of 220V, the actual allowable range of 320V DC voltage is 320V+ / -15%. 320V DC (Direct Current) is selected here, and the voltage stabilization link of the DC / DC converter ensures that its error range is within 1%, which can fully meet the use of on-board chargers.

[0052] In actual application, the DC conversion module is set in the charging pile, that is, the charging pile is improved according to 800V DC input. The original AC charging pile is transformed to accept 800V DC input, and the car can be charged through the electric vehicle slow charging interface. The electric vehicle slow charging interface is not directly connected to the battery, but connected to the input end of the on-board charger.

[0053] An embodiment of the present application provides a charging pile, which includes: the above-mentioned charging circuit structure.

[0054] like Figure 1 As shown, the charging circuit structure 1 specifically includes: an input module 11 , a transformer and rectifier module 12 and a DC conversion module 13 .

[0055] The input module 11 provides a supply voltage to be processed.

[0056] The transformer and rectifier module 12 is connected to the input module 11 , and performs transformer and rectification on the supply voltage to output a first DC voltage.

[0057] The DC conversion module 13 is connected to the transformer and rectifier module 12 to convert the first DC voltage into a second DC voltage directly used for on-board charging.

[0058] In one embodiment, the input module includes a 10 kV AC power supply system. The 10 kV AC power supply system is electrically connected to the transformer and rectifier module via three phases. Specifically, the transformer and rectifier module includes a transformer rectifier.

[0059] like Figure 2 As shown, the 10kV AC (power supply) system is connected to the transformer rectifier through three-phase electricity A, B, and C, and outputs 800V DC through the transformer rectifier. The 800V DC is transmitted to the charging pile of the electric vehicle through subsequent cable laying.

[0060] In another embodiment, the input module includes a 10kV AC power supply system and a 380V AC power supply system. The 380V AC power supply system is electrically connected to the transformer and rectifier module through three phases. Specifically, the transformer and rectifier module includes a transformer rectifier. Further, the charging circuit structure also includes: a step-down transformer module. The input end of the step-down transformer module is connected to the 10kV AC power supply system, and the output end is connected to the 380V AC power supply system. Specifically, the step-down transformer module includes a step-down transformer that reduces voltage from 10kV to 380V.

[0061] like Figure 3 As shown, the 10kV AC (power supply) system is connected to a step-down transformer that reduces 10kV to 380V through three-phase electricity A, B, and C. The step-down transformer outputs 380V AC three-phase electricity A, B, and C to the transformer-rectifier, and outputs 800V DC through the transformer-rectifier. The 800V DC is transmitted to the charging pile of the electric vehicle through subsequent cable laying.

[0062] In one embodiment, the DC conversion module is disposed in a charging pile, and the charging line structure further comprises: a cable laid from the transformer and rectifier module to each charging pile of the charging station.

[0063] One end of the cable is connected to the transformer and rectifier module, and the other end is connected to the DC conversion module of each charging pile; the cable is used to transmit the first DC voltage from the transformer and rectifier module to each charging pile of the charging station.

[0064] In one embodiment, the first DC voltage is a DC voltage value in the range of 700V-900V.

[0065] Specifically, the first DC voltage is 800V, and the traditional 220V AC power supply cable is replaced by an 800V DC cable. Under the same voltage drop and transmission distance, the cable cost required for the 800V voltage level is only less than 10% of that under the 220V voltage. Correspondingly, the original 220V input charging pile is changed to a charging pile with 800V DC as input and 320V DC as output. This application further improves the effect of the implementation of this solution by reducing the scope of modification to the pile to a minimum.

[0066] In one embodiment, the second DC voltage is 320 V. It should be noted that 320 VDC is not an absolute fixed value, and the voltage fluctuation range may be 320 VDC+ / -1%.

[0067] In actual application, the DC conversion module is set in the charging pile, that is, the charging pile is improved according to 800V DC input. The original AC charging pile is transformed to accept 800V DC input, and the car can be charged through the electric vehicle slow charging interface. The electric vehicle slow charging interface is not directly connected to the battery, but connected to the input end of the on-board charger.

[0068] See also Figure 4 , which is a schematic diagram showing the structural connection of the power supply system for the vehicle charger according to the embodiment of the present application. Figure 4 As shown, an embodiment of the present application provides a power supply system for a vehicle-mounted charger, and the power supply system for the vehicle-mounted charger includes: a charging pile using a charging line structure 1 and an on-board charger of an electric vehicle 2; the charging pile and the on-board charger are electrically connected via a charging port of the electric vehicle.

[0069] The charging pile outputs 320V direct current to the charging port of the electric vehicle to charge the on-board charger of the electric vehicle.

[0070] See also Figure 5 , which shows a circuit structure diagram of a power supply system for a vehicle charger according to an embodiment of the present application. Figure 5 As shown, the 10kV AC (power supply) system is connected to the transformer rectifier through three-phase electricity A, B, and C, and outputs 800V DC through the transformer rectifier. The 800V DC is transmitted to the charging pile of the electric vehicle through subsequent cable laying. The charging pile includes a DC circuit breaker and a DC conversion module (a DCDC power supply that converts 800V DC into 320V DC), and then the 320V converted output by the charging pile is used to charge the electric vehicle.

[0071] In one embodiment, the on-board charger includes: a filter, a PFC (Power Factor Correction) circuit, a first capacitor, a DC transformer module, a second capacitor and a battery.

[0072] The filter receives the 320V DC power output by the charging pile, and charges the battery through the PFC circuit, the first capacitor, the DC transformer module, and the second capacitor.

[0073] See also Figure 6 , which shows the electrical architecture diagram of the on-board charger of the power supply system for the on-board charger according to the embodiment of the present application. Figure 6As shown, the on-board charger includes: a filter, a PFC circuit, a first capacitor C01, a DC transformer module, a second capacitor C02 and a battery. Figure 5 The charging pile in the output 320VDC to Figure 6 The on-board charger of electric vehicles. First, 320V DC passes through Figure 6 The universal filter in the power supply eliminates the harmonics and interference of the 320V DC voltage. The filtered 320VDC is then input into the PFC circuit, filtered again and boosted by the PFC circuit to output 400V DC to the next two-stage DC DC circuit. The voltage is then bucked and converted by the two-stage DC DC circuit to charge the electric vehicle battery. (The first-stage DC DC circuit converts the 400V DC into a more stable direct current (200V DC-500V DC) suitable for charging the car battery. The second-stage DC DC circuit senses the voltage from the first-stage DC DC circuit, and then charges the car battery after synchronous bucking and converting. The second-stage DC DC circuit also has the function of electrical isolation to ensure charging safety.

[0074] See also Figure 7 , which shows the PFC circuit electrical diagram of the power supply system for the vehicle charger according to the embodiment of the present application. Figure 7 As shown, it means Figure 6 The filtered 320V DC is directly input into the PFC circuit, which mainly functions as filtering and boosting. Figure 6 The PFC circuit does not distinguish between AC and DC, and can operate normally as long as the voltage level meets the requirements. Therefore, it is technically possible to use 320VDC to power the on-board charger.

[0075] Combination Figure 6 and Figure 7 Although the slow charging interface requires 220V AC input, the PFC circuit does not distinguish between DC and AC. As long as the voltage level meets the requirements, it can operate normally. For example, using the peak voltage of 220V AC 320V as DC input can also charge normally, and it can also make the on-board charger at the optimal efficiency. Therefore, the change to the charging pile is to add a 800V to 320V DC / DC converter at the input end, and replace the original AC switch with a DC switch at the output end. Of course, the internal metering device and corresponding settings are changed from AC to DC.

[0076] In practical applications, a specific implementation case of this application is an electric vehicle charging system in an underground parking lot of an old residential area. The community has 1,560 parking spaces, 2 power distribution rooms, and about 100 new energy vehicles. At present, about 40 7kW charging piles have been installed, and there is still a gap of 60 charging piles.

[0077] The community originally planned to build a new transformer next to the switch station at the entrance of the community and set up a distribution box in the underground yard to supply power to the charging piles. However, the new transformer is about 200 meters away from the distribution box. The distance from the distribution box to the parking charging pile is mostly about 50 to 150 meters. The use of AC power supply will greatly increase the construction cost and cable cost due to the long distance and large cross-sectional area of ​​the cable used.

[0078] The community currently uses a DC 800V power supply solution to power the newly built charging piles. Figure 2 The multi-pulse transformer rectifier shown. The input voltage of the multi-pulse transformer rectifier is three-phase AC 10kV, and the output voltage is 800V DC for power supply. The ordinary 7KW slow charging pile originally planned to be installed is replaced with a 7kW slow charging pile with 800V DC as input and 320V DC as output to charge new energy vehicles.

[0079] Based on the shortfall of 60 7kW charging piles in the community, and considering that charging at night is the peak period and the charging pile simultaneous rate is 0.6, the capacity of the transformer is 250kVA. Each distribution cabinet has a total capacity of 70kW with 1 input and 10 outputs, and the distance from the distribution cabinet to the charging pile is 100 meters. Although transformer rectifiers have been added, and step-down devices have been installed inside each DC input and output slow charging pile, the problems of too large an underground parking lot in the community, too many parking spaces, and long distribution distances for charging piles have been solved. The overall cost of the project has not increased, but has decreased by 35%.

[0080] In the several embodiments provided in the present application, it should be understood that the disclosed circuit structure or system can be implemented in other ways. For example, the structural embodiments described above are only schematic. For example, the division of modules / units is only a logical function division. There may be other division methods in actual implementation, such as multiple modules or units can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be an indirect coupling or communication connection through some interfaces, devices or modules or units, which can be electrical, mechanical or other forms.

[0081] The modules / units described as separate components may or may not be physically separated, and the components displayed as modules / units may or may not be physical modules, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the modules / units may be selected according to actual needs to achieve the purpose of the embodiments of the present application. For example, the functional modules / units in the various embodiments of the present application may be integrated into one processing module, or each module / unit may exist physically separately, or two or more modules / units may be integrated into one module / unit.

[0082] The above embodiments are merely illustrative of the principles and effects of the present application and are not intended to limit the present application. Anyone familiar with the technology may modify or change the above embodiments without violating the spirit and scope of the present application. Therefore, all equivalent modifications or changes made by a person of ordinary skill in the art without departing from the spirit and technical ideas disclosed in the present application shall still be covered by the claims of the present application.

Claims

1. A charging circuit structure, characterized in that: The charging circuit structure comprises: An input module provides a supply voltage to be processed; A transformer and rectifier module, connected to the input module, transforms and rectifies the supply voltage to output a first DC voltage; the first DC voltage is a DC voltage value within a range of 700V-900V; A DC conversion module, connected to the transformer and rectifier module, converts the first DC voltage into a second DC voltage directly used for on-board charging; the second DC voltage is 320V; The input module includes a 10kV AC power supply system, which is electrically connected to the transformer and rectifier module via three phases; or the input module includes a 10kV AC power supply system and a 380V AC power supply system, which is electrically connected to the transformer and rectifier module via three phases; The DC conversion module is arranged in the charging pile, and the charging line structure also includes: a cable laid from the transformer and rectifier module to each charging pile of the charging station; one end of the cable is connected to the transformer and rectifier module, and the other end is connected to the DC conversion module of each charging pile; the cable is used to transmit the first DC voltage from the transformer and rectifier module to each charging pile of the charging station.

2. The charging circuit structure according to claim 1, characterized in that: The charging circuit structure further includes: a step-down transformer module; The input end of the step-down transformer module is connected to the 10kV AC power supply system, and the output end is connected to the 380V AC power supply system.

3. A charging pile, characterized in that: The charging pile comprises: the charging circuit structure according to any one of claims 1 to 2.

4. A power supply system for a vehicle charger, characterized in that: The power supply system for the on-board charger comprises: the charging pile according to claim 3 and the on-board charger of the electric vehicle; the charging pile and the on-board charger are electrically connected through the charging port of the electric vehicle; The charging pile outputs 320V direct current to the charging port of the electric vehicle to charge the on-board charger of the electric vehicle.

5. The power supply system for a vehicle charger according to claim 4, characterized in that: The on-board charger comprises: a filter, a PFC circuit, a first capacitor, a DC transformer module, a second capacitor and a battery; The filter receives the 320V DC power output by the charging pile, and charges the battery through the PFC circuit, the first capacitor, the DC transformer module, and the second capacitor.

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