A direct current fast charging full-body pile charging control method and system

Abstract

The application provides a direct current fast charging full-body pile charging control method and system in the technical field of direct current charging piles, and the method comprises the following steps: step S10, setting a calculation rule of a required current upper limit protection value Iup; step S20, a PDU module obtains a required current Ineed from a BMS of a new energy vehicle, and calculates Iup based on the calculation rule and Ineed; step S30, the PDU module collects an output current Iout of a DC / DC module to a direct current charging pile in real time through a voltage and current collection module; step S40, the PDU module performs current protection based on Iup and Iout; step S50, the PDU module performs current suppression based on Iup and Iout; step S60, the PDU module obtains a maximum output current Icharge of the direct current charging pile, and controls the DC / DC module to perform trickle output to the direct current charging pile based on Iup and Icharge. The application has the advantage that the safety of direct current charging pile charging is greatly improved.

Description

Technical Field

[0001] The present invention relates to the technical field of DC charging piles, and in particular to a DC fast charging pile charging control method and system. Background Art

[0002] With the continued rapid growth in sales of new energy vehicles, the market demand for charging piles is strong. Long queues during peak charging hours are common, and the length of charging time has become an important factor in whether users buy new energy vehicles. Therefore, there is an urgent need for high-power charging equipment with faster charging speeds. The construction of charging infrastructure has become an important guarantee for the popularization of new energy vehicles.

[0003] Compared to AC charging piles, DC charging piles offer faster charging speeds and higher output power, making them fast-charging piles. Existing DC charging piles typically have output powers of 80kW, 160kW, or 240kW. Their high voltage and high current output ensure rapid charging for new energy vehicles, alleviating some of the anxiety users have about charging times.

[0004] New energy vehicles (NEVs) are typically charged at a constant current. Therefore, precise current control during high-power charging is a crucial safety barrier for NEVs, preventing spontaneous combustion incidents to a certain extent. However, traditional DC charging piles, which protect against charging current by limiting the maximum current, have the following shortcomings: 1. They cannot dynamically protect against fluctuating demand currents; 2. They cannot dynamically suppress current output based on actual output current to prevent it from exceeding demand; and 3. When the demand current approaches the upper limit, no measures are taken to prevent the current from exceeding the upper limit.

[0005] Therefore, how to provide a DC fast charging pile charging control method and system to improve the safety of DC charging pile charging has become a technical problem that needs to be solved urgently. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to provide a DC fast charging pile charging control method and system to improve the safety of DC charging pile charging.

[0007] In a first aspect, the present invention provides a method for controlling charging of a DC fast charging pile, comprising the following steps:

[0008] Step S10: setting a calculation rule for a demand current upper limit protection value Iup;

[0009] Step S20: The PDU module obtains the demand current Ineed from the BMS of the new energy vehicle and calculates Iup based on the calculation rule and Ineed;

[0010] Step S30: The PDU module collects the output current Iout of the DCDC module to the DC charging pile in real time through the voltage and current acquisition module;

[0011] Step S40: The PDU module performs current protection based on the Iup and Iout;

[0012] Step S50: The PDU module performs current suppression based on the Iup and Iout;

[0013] Step S60: The PDU module obtains the maximum output current Icharge of the DC charging pile, and controls the DCDC module to output trickle current to the DC charging pile based on the Iup and Icharge;

[0014] The steps S40, S50 and S60 are performed in no particular order.

[0015] Furthermore, in step S10, the calculation rule is specifically as follows:

[0016] When Ineed < 30A, Iup = Ineed + 3A;

[0017] When Ineed≥30A, Iup=Ineed*1.025+1A.

[0018] Furthermore, the step S40 is specifically as follows:

[0019] The PDU module sets a first time threshold. When it is detected that Iout>Iup and the duration is continuously greater than the first time threshold, the current protection mechanism is triggered to stop the power output of the DCDC module.

[0020] Furthermore, the step S50 is specifically as follows:

[0021] The PDU module sets a second time threshold. When it detects that Iout>(Iup-1A) and the duration is continuously greater than the second time threshold, the current suppression mechanism is triggered. Otherwise, the current suppression mechanism is exited.

[0022] The current suppression mechanism is specifically as follows: let Z = |Iout-Ineed|, and update the value of Ineed to Ineed-2*Z.

[0023] Furthermore, the step S60 is specifically as follows:

[0024] The PDU module obtains the maximum output current Icharge of the DC charging pile. When Ineed>Icharge-5A, the trickle charging mechanism is triggered;

[0025] The trickle charging mechanism is specifically as follows: a current increase threshold Ia is set. When the current output by the DCDC module to the DC charging pile reaches Icharge-5A, the output current of the DCDC module is increased by 500mA every 100ms until the output current value reaches Iup.

[0026] In a second aspect, the present invention provides a DC fast charging pile control system, comprising the following modules:

[0027] A protection value calculation rule setting module is used to set a calculation rule for a demand current upper limit protection value Iup;

[0028] An Iup calculation module is used for the PDU module to obtain the demand current Ineed from the BMS of the new energy vehicle and calculate Iup based on the calculation rule and Ineed;

[0029] The Iout acquisition module is used by the PDU module to collect the output current Iout of the DCDC module to the DC charging pile in real time through the voltage and current acquisition module;

[0030] A current protection module, used for the PDU module to perform current protection based on the Iup and Iout;

[0031] A current suppression module, used for the PDU module to suppress current based on the Iup and Iout;

[0032] The trickle output module is used for the PDU module to obtain the maximum output current Icharge of the DC charging pile, and based on the Iup and Icharge, controls the DCDC module to perform trickle output to the DC charging pile.

[0033] Furthermore, in the protection value calculation rule setting module, the calculation rule is specifically as follows:

[0034] When Ineed < 30A, Iup = Ineed + 3A;

[0035] When Ineed≥30A, Iup=Ineed*1.025+1A.

[0036] Furthermore, the current protection module is specifically used to:

[0037] The PDU module sets a first time threshold. When it is detected that Iout>Iup and the duration is continuously greater than the first time threshold, the current protection mechanism is triggered to stop the power output of the DCDC module.

[0038] Furthermore, the current suppression module is specifically used to:

[0039] The PDU module sets a second time threshold. When it detects that Iout>(Iup-1A) and the duration is continuously greater than the second time threshold, the current suppression mechanism is triggered. Otherwise, the current suppression mechanism is exited.

[0040] The current suppression mechanism is specifically as follows: let Z = |Iout-Ineed|, and update the value of Ineed to Ineed-2*Z.

[0041] Furthermore, the trickle output module is specifically used for:

[0042] The PDU module obtains the maximum output current Icharge of the DC charging pile. When Ineed>Icharge-5A, the trickle charging mechanism is triggered;

[0043] The trickle charging mechanism is specifically as follows: a current increase threshold Ia is set. When the current output by the DCDC module to the DC charging pile reaches Icharge-5A, the output current of the DCDC module is increased by 500mA every 100ms until the output current value reaches Iup.

[0044] The advantages of the present invention are:

[0045] The PDU module obtains the demand current Ineed from the BMS of the new energy vehicle, and calculates the demand current upper limit protection value Iup based on the set calculation rules and Ineed. The PDU module collects the output current Iout of the DCDC module to the DC charging pile in real time through the voltage and current acquisition module; the PDU module performs current protection based on Iup and Iout, and current suppression based on Iup and Iout, obtains the maximum output current Icharge of the DC charging pile, and controls the DCDC module to output trickle current to the DC charging pile based on Iup and Icharge; that is, when the output current is greater than the demand current upper limit protection value and is continuously greater than the set first time threshold, the current protection mechanism is triggered to stop charging, dynamically check and suppress current output, reduce the possibility of overcurrent faults during charging, and slowly increase the current through trickle current to prevent the output current from exceeding the current upper limit protection value, reduce the hardware impact on the DC charging pile, extend the hardware life, and ultimately greatly improve the safety of DC charging pile charging. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0047] Figure 1 The present invention is a flow chart of a DC fast charging pile control method.

[0048] Figure 2 It is a structural diagram of a DC fast charging pile charging control system of the present invention.

[0049] Figure 3 It is a schematic diagram of the hardware architecture of the present invention. DETAILED DESCRIPTION

[0050] The technical solution in the embodiment of the present application has the following overall idea: the PDU module performs current protection based on Iup and Iout, performs current suppression based on Iup and Iout, obtains the maximum output current Icharge of the DC charging pile, and controls the DCDC module to perform trickle output to the DC charging pile based on Iup and Icharge, so as to improve the safety of charging of the DC charging pile.

[0051] Please refer to Figures 1 to 3 As shown, a preferred embodiment of a DC fast charging control method of the present invention includes the following steps:

[0052] Step S10: setting a calculation rule for a demand current upper limit protection value Iup;

[0053] Step S20: The PDU module (power distribution module) obtains the demand current Ineed from the BMS (battery management system) of the new energy vehicle and calculates Iup based on the calculation rule and Ineed;

[0054] Step S30: The PDU module collects the output current Iout of the DCDC module to the DC charging pile in real time through the voltage and current acquisition module;

[0055] Step S40: The PDU module performs current protection based on the Iup and Iout;

[0056] Step S50: The PDU module performs current suppression based on the Iup and Iout;

[0057] Step S60: The PDU module obtains the maximum output current Icharge of the DC charging pile, and controls the DCDC module to output trickle current to the DC charging pile based on the Iup and Icharge;

[0058] The steps S40, S50 and S60 are performed in no particular order.

[0059] When the DC charging pile is working, the present invention monitors in real time whether the output current exceeds the demand current Ineed, and can effectively correct when the output current deviation of the DCDC module is large. When the demand current Ineed is close to the demand current upper limit protection value Iup, the output current is slowly raised to effectively prevent the overcurrent protection mechanism from being triggered.

[0060] In step S10, the calculation rule is specifically:

[0061] When Ineed < 30A, Iup = Ineed + 3A;

[0062] When Ineed≥30A, Iup=Ineed*1.025+1A.

[0063] The step S40 is specifically as follows:

[0064] The PDU module sets a first time threshold. When it is detected that Iout>Iup and the duration is often greater than the first time threshold, the current protection mechanism is triggered to stop the power output of the DCDC module. The first time threshold is preferably 3 seconds.

[0065] The step S50 is specifically as follows:

[0066] The PDU module sets a second time threshold. When Iout>(Iup-1A) is detected and the duration is continuously greater than the second time threshold, the current suppression mechanism is triggered. Otherwise, the current suppression mechanism is exited. The second time threshold is preferably 1 second.

[0067] The current suppression mechanism is specifically as follows: let Z = |Iout-Ineed|, and update the value of Ineed to Ineed-2*Z.

[0068] The step S60 is specifically as follows:

[0069] The PDU module obtains the maximum output current Icharge of the DC charging pile. When Ineed>Icharge-5A, the trickle charging mechanism is triggered;

[0070] The trickle charging mechanism is specifically as follows: a current increase threshold Ia is set. When the current output by the DCDC module to the DC charging pile reaches Icharge-5A, the output current of the DCDC module is increased by 500mA every 100ms until the output current reaches Iup. That is, the output current is slowly increased to reduce the impact on the hardware of the DC charging pile.

[0071] A preferred embodiment of a DC fast charging pile charging control system of the present invention includes the following modules:

[0072] A protection value calculation rule setting module is used to set a calculation rule for a demand current upper limit protection value Iup;

[0073] An Iup calculation module is used for the PDU module (power distribution module) to obtain the demand current Ineed from the BMS (battery management system) of the new energy vehicle and calculate Iup based on the calculation rule and Ineed;

[0074] The Iout acquisition module is used by the PDU module to collect the output current Iout of the DCDC module to the DC charging pile in real time through the voltage and current acquisition module;

[0075] A current protection module, used for the PDU module to perform current protection based on the Iup and Iout;

[0076] A current suppression module, used for the PDU module to suppress current based on the Iup and Iout;

[0077] The trickle output module is used for the PDU module to obtain the maximum output current Icharge of the DC charging pile, and based on the Iup and Icharge, controls the DCDC module to perform trickle output to the DC charging pile.

[0078] When the DC charging pile is working, the present invention monitors in real time whether the output current exceeds the demand current Ineed, and can effectively correct when the output current deviation of the DCDC module is large. When the demand current Ineed is close to the demand current upper limit protection value Iup, the output current is slowly raised to effectively prevent the overcurrent protection mechanism from being triggered.

[0079] In the protection value calculation rule setting module, the calculation rule is specifically as follows:

[0080] When Ineed < 30A, Iup = Ineed + 3A;

[0081] When Ineed≥30A, Iup=Ineed*1.025+1A.

[0082] The current protection module is specifically used for:

[0083] The PDU module sets a first time threshold. When it is detected that Iout>Iup and the duration is often greater than the first time threshold, the current protection mechanism is triggered to stop the power output of the DCDC module. The first time threshold is preferably 3 seconds.

[0084] The current suppression module is specifically used for:

[0085] The PDU module sets a second time threshold. When Iout>(Iup-1A) is detected and the duration is continuously greater than the second time threshold, the current suppression mechanism is triggered. Otherwise, the current suppression mechanism is exited. The second time threshold is preferably 1 second.

[0086] The current suppression mechanism is specifically as follows: let Z = |Iout-Ineed|, and update the value of Ineed to Ineed-2*Z.

[0087] The trickle output module is specifically used for:

[0088] The PDU module obtains the maximum output current Icharge of the DC charging pile. When Ineed>Icharge-5A, the trickle charging mechanism is triggered;

[0089] The trickle charging mechanism is specifically as follows: a current increase threshold Ia is set. When the current output by the DCDC module to the DC charging pile reaches Icharge-5A, the output current of the DCDC module is increased by 500mA every 100ms until the output current reaches Iup. That is, the output current is slowly increased to reduce the impact on the hardware of the DC charging pile.

[0090] In summary, the advantages of the present invention are:

[0091] The PDU module obtains the demand current Ineed from the BMS of the new energy vehicle, and calculates the demand current upper limit protection value Iup based on the set calculation rules and Ineed. The PDU module collects the output current Iout of the DCDC module to the DC charging pile in real time through the voltage and current acquisition module; the PDU module performs current protection based on Iup and Iout, and current suppression based on Iup and Iout, obtains the maximum output current Icharge of the DC charging pile, and controls the DCDC module to output trickle current to the DC charging pile based on Iup and Icharge; that is, when the output current is greater than the demand current upper limit protection value and is continuously greater than the set first time threshold, the current protection mechanism is triggered to stop charging, dynamically check and suppress current output, reduce the possibility of overcurrent faults during charging, and slowly increase the current through trickle current to prevent the output current from exceeding the current upper limit protection value, reduce the hardware impact on the DC charging pile, extend the hardware life, and ultimately greatly improve the safety of DC charging pile charging.

[0092] Although the specific embodiments of the present invention are described above, those skilled in the art should understand that the specific embodiments described are merely illustrative and are not intended to limit the scope of the present invention. Equivalent modifications and changes made by those skilled in the art in accordance with the spirit of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A DC fast charging pile charging control method, characterized by: The steps include: Step S10: Set a calculation rule for the upper limit protection value Iup of the demand current; the calculation rule is specifically as follows: When Ineed < 30A, Iup = Ineed + 3A; When Ineed ≥ 30A, Iup = Ineed * 1.025 + 1A; Step S20: The PDU module obtains the demand current Ineed from the BMS of the new energy vehicle and calculates Iup based on the calculation rule and Ineed; Step S30: The PDU module collects the output current Iout of the DCDC module to the DC charging pile in real time through the voltage and current acquisition module; Step S40: The PDU module performs current protection based on the Iup and Iout; Step S50: The PDU module performs current suppression based on the Iup and Iout; Step S60: The PDU module obtains the maximum output current Icharge of the DC charging pile, and controls the DCDC module to output trickle current to the DC charging pile based on the Iup and Icharge; The steps S40, S50 and S60 are performed in no particular order.

2. A DC fast charging pile charging control method according to claim 1, characterized in that: The step S40 is specifically as follows: The PDU module sets a first time threshold. When it is detected that Iout>Iup and the duration is longer than the first time threshold, the current protection mechanism is triggered to stop the power output of the DCDC module.

3. The DC fast charging pile charging control method according to claim 1, characterized in that: The step S50 is specifically as follows: The PDU module sets a second time threshold. When it detects that Iout>(Iup-1A) and the duration is longer than the second time threshold, the current suppression mechanism is triggered. Otherwise, the current suppression mechanism is exited. The current suppression mechanism is specifically as follows: let Z = |Iout-Ineed|, and update the value of Ineed to Ineed-2*Z.

4. The DC fast charging pile charging control method according to claim 1, characterized in that: The step S60 is specifically as follows: The PDU module obtains the maximum output current Icharge of the DC charging pile. When Ineed>Icharge-5A, the trickle charging mechanism is triggered; The trickle charging mechanism is specifically as follows: a current increase threshold Ia is set. When the current output by the DCDC module to the DC charging pile reaches Icharge-5A, the output current of the DCDC module is increased by 500mA every 100ms until the output current value reaches Iup.

5. A DC fast charging pile charging control system, characterized by: Includes the following modules: The protection value calculation rule setting module is used to set a calculation rule for the demand current upper limit protection value Iup; the calculation rule is specifically: When Ineed < 30A, Iup = Ineed + 3A; When Ineed ≥ 30A, Iup = Ineed * 1.025 + 1A; An Iup calculation module is used for the PDU module to obtain the demand current Ineed from the BMS of the new energy vehicle and calculate Iup based on the calculation rule and Ineed; The Iout acquisition module is used by the PDU module to collect the output current Iout of the DCDC module to the DC charging pile in real time through the voltage and current acquisition module; A current protection module, used for the PDU module to perform current protection based on the Iup and Iout; A current suppression module, used for the PDU module to suppress current based on the Iup and Iout; The trickle output module is used for the PDU module to obtain the maximum output current Icharge of the DC charging pile, and based on the Iup and Icharge, controls the DCDC module to perform trickle output to the DC charging pile.

6. A DC fast charging pile charging control system according to claim 5, characterized in that: The current protection module is specifically used for: The PDU module sets a first time threshold. When it is detected that Iout>Iup and the duration is longer than the first time threshold, the current protection mechanism is triggered to stop the power output of the DCDC module.

7. A DC fast charging pile charging control system according to claim 5, characterized in that: The current suppression module is specifically used for: The PDU module sets a second time threshold. When it detects that Iout>(Iup-1A) and the duration is longer than the second time threshold, the current suppression mechanism is triggered. Otherwise, the current suppression mechanism is exited. The current suppression mechanism is specifically as follows: let Z = |Iout-Ineed|, and update the value of Ineed to Ineed-2*Z.

8. The DC fast charging pile charging control system according to claim 5, characterized in that: The trickle output module is specifically used for: The PDU module obtains the maximum output current Icharge of the DC charging pile. When Ineed>Icharge-5A, the trickle charging mechanism is triggered; The trickle charging mechanism is specifically as follows: a current increase threshold Ia is set. When the current output by the DCDC module to the DC charging pile reaches Icharge-5A, the output current of the DCDC module is increased by 500mA every 100ms until the output current value reaches Iup.

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