Control method and device of pure electric bus, pure electric bus and storage medium

Abstract

The application discloses a control method and device of a pure electric bus, the pure electric bus, and a storage medium. The battery of the pure electric bus is provided with an auxiliary relay and a main relay. The method comprises the following steps: after receiving a high-voltage request sent by a BMS, it is determined whether to pre-charge the battery according to first-stage state parameters before pre-charging starts, the auxiliary relay is turned on, and the battery is pre-charged; it is determined whether the pre-charging is completed according to second-stage state parameters after the pre-charging starts and before charging starts, the auxiliary relay is turned off to end the pre-charging, and the main relay is turned on to charge; and it is determined whether the charging is completed according to third-stage state parameters after the charging starts and before the charging is completed, and the main relay is turned off to end the charging. According to the scheme, the battery and the whole vehicle are pre-charged in the pre-charging stage, and the charging is performed only when it is determined that the whole vehicle is in a chargeable state, so that the safety of the charging can be ensured.

Description

Technical Field

[0001] This invention belongs to the field of pure electric bus technology, specifically relating to a charging control method, device, pure electric bus, and storage medium for a pure electric bus. Background Technology

[0002] In response to the national policy advocating energy conservation and emission reduction, most buses have adopted a pure electric operating mode. In this mode, buses need to be equipped with a battery structure to form a pure electric bus. The charging method for pure electric buses is primarily plug-in; to meet certain driving range requirements, the batteries store a relatively high amount of electricity.

[0003] When the battery power is low, a DC-DC converter can be used to charge the battery through a high-voltage platform, such as a charging station. However, the safety of charging through this high-voltage platform cannot be guaranteed.

[0004] The above content is only used to help understand the technical solution of the present invention and does not represent an admission that the above content is prior art. Summary of the Invention

[0005] The purpose of this invention is to provide a control method, device, pure electric bus, and storage medium for a pure electric bus, in order to solve the problem that the safety of charging cannot be guaranteed during the charging process of charging the battery through the high-voltage platform of the power battery. The invention achieves the effect of ensuring charging safety by first entering a pre-charging stage to pre-charge the battery and the whole vehicle when the whole vehicle receives the charging execution signal, and only starting charging when it is determined that the whole vehicle is in a rechargeable state.

[0006] This invention provides a control method for a pure electric bus. The pure electric bus has a battery and a BMS (Battery Management System). A main relay for controlling the charging of the battery is provided at the battery location, and an auxiliary relay for controlling the pre-charging of the battery is also provided. The pre-charging stage is a stage preceding the charging stage. Before the battery pre-charging, both the main relay and the auxiliary relay are in an open state. The control method for the pure electric bus includes: when the battery power is insufficient to a set power level and the pure electric bus has arrived at a charging station, determining whether a high-voltage request has been received from the BMS; if it is determined that a high-voltage request has been received from the BMS, acquiring the vehicle status parameters of the pure electric bus; the vehicle status parameters of the pure electric bus include: a first-stage status parameter before pre-charging begins, a second-stage status parameter after pre-charging begins and before charging begins, and a third-stage status parameter after charging begins and before charging is completed. Based on the first-stage state parameters, determine whether the overall vehicle state of the pure electric bus and the battery state are suitable for pre-charging the battery. If the overall vehicle state of the pure electric bus and the battery state are suitable for pre-charging the battery, control the auxiliary relay to turn on to pre-charge the battery. While pre-charging the battery, after controlling the auxiliary relay to turn on for a first set time, determine whether the pre-charging of the battery has been completed based on the second-stage state parameters. If the pre-charging of the battery is completed, control the main relay to turn on for a second set time, then control the auxiliary relay to turn off to charge the battery. While charging the battery, determine whether the charging of the battery has been completed based on the third-stage state parameters. If the charging of the battery is completed, after all loads on the battery are turned off, control the main relay to turn off to complete the charging control of the battery.

[0007] In some embodiments, the first-stage state parameters include: the output voltage of the DC-DC converter of the pure electric bus, the voltage of the BMS, the value of the status flag bit of the air conditioning high-voltage contactor of the pure electric bus, and the low-voltage of the main controller of the pure electric bus; based on the first-stage state parameters, determining whether the overall state of the pure electric bus and the battery state are suitable for pre-charging the battery includes: determining whether the following conditions are met: the output voltage of the DC-DC converter of the pure electric bus is greater than a first set voltage, the voltage of the BMS is greater than a second set voltage, the value of the status flag bit of the air conditioning high-voltage contactor of the pure electric bus is a set flag value, and the low-voltage of the main controller of the pure electric bus is greater than a third set voltage; if these conditions are met, it is determined that the overall state of the pure electric bus and the battery state are suitable for pre-charging the battery.

[0008] In some embodiments, the second-stage state parameters include: the bus voltage of the main controller of the pure electric bus, the bus voltage of the compressor in the air conditioning system of the pure electric bus, and the communication connection establishment status between the main controller and the driver of the pure electric bus. When pre-charging the battery, after controlling the auxiliary relay to turn on for a first set time, based on the second-stage state parameters, it is determined whether the pre-charging of the battery has been completed, including: determining whether the following conditions are met: the bus voltage of the main controller of the pure electric bus drops, or the bus voltage of the compressor in the air conditioning system of the pure electric bus is less than a fourth set voltage and the bus voltage of the main controller of the pure electric bus is less than a fifth set voltage, or the communication connection establishment status between the main controller and the driver of the pure electric bus is not established; if not met, it is determined that the pre-charging of the battery has been completed; if met, it is determined that the pre-charging of the battery has not been completed.

[0009] In some embodiments, when pre-charging the battery, after controlling the auxiliary relay to turn on for a first set time, determining whether the pre-charging of the battery has been completed based on the second stage state parameters, further includes: if it is determined that the pre-charging of the battery has not been completed, delaying for a third set time, and then re-pre-charging the battery; and accumulating and counting the number of times the pre-charging of the battery has not been completed to obtain the number of pre-charging failures; if the number of pre-charging failures reaches the set number, then initiating a charging fault reminder message for the battery and ending the charging control of the battery.

[0010] In some implementations, the third-stage state parameters include: the bus voltage of the driver of the pure electric bus, the command sent by the driver of the compressor in the air conditioning system of the pure electric bus to release the main relay, the bus voltage of the main controller of the pure electric bus, and the low-voltage of the main controller of the pure electric bus; when charging the battery, determining whether the charging of the battery has been completed according to the third-stage state parameters includes: determining whether the following conditions are met: the pure electric bus If the bus voltage of the vehicle's drive is less than the fifth preset voltage, or the bus voltage of the pure electric bus's drive experiences low-voltage protection, or a command to release the main relay is received from the driver of the compressor in the air conditioning unit of the pure electric bus, or the bus voltage of the main controller of the pure electric bus is less than the sixth preset voltage, or the low-voltage of the main controller of the pure electric bus is the seventh preset voltage; if these conditions are met, it is determined that the battery charging is complete; if not, it is determined that the battery charging is incomplete.

[0011] In conjunction with the above method, another aspect of the present invention provides a control device for a pure electric bus, the pure electric bus having a battery and a BMS; a main relay for controlling the charging of the battery is provided at the battery, and an auxiliary relay for controlling the pre-charging of the battery is also provided; the pre-charging stage is a stage preceding the charging stage; before the battery is pre-charged, both the main relay and the auxiliary relay are in an open state; the control device for the pure electric bus includes: a control unit configured to determine whether a high-voltage request sent by the BMS has been received when the battery power is less than a set power and the pure electric bus has arrived at a charging station; an acquisition unit configured to acquire the vehicle status parameters of the pure electric bus if it is determined that a high-voltage request sent by the BMS has been received; the vehicle status parameters of the pure electric bus include: a first stage status parameter before the start of pre-charging, a second stage status parameter after the start of pre-charging and before the start of charging, and a third stage status parameter after the start of charging and before the completion of charging; the control unit is further configured to, according to the first stage status parameter... The control unit is configured to determine, based on the second stage state parameters, whether the overall vehicle state of the pure electric bus and the battery state are suitable for pre-charging the battery. The control unit is further configured to, if it is determined that the overall vehicle state of the pure electric bus and the battery state are suitable for pre-charging the battery, control the auxiliary relay to activate and pre-charge the battery. The control unit is also configured to, while pre-charging the battery, after controlling the auxiliary relay to activate for a first predetermined time, determine, based on the second stage state parameters, whether the pre-charging of the battery has been completed. The control unit is further configured to, upon determining that the pre-charging of the battery has been completed, control the main relay to turn on for a second predetermined time, and then control the auxiliary relay to turn off to charge the battery; the control unit is further configured to, while charging the battery, determine whether the charging of the battery has been completed based on the third stage state parameters; the control unit is further configured to, upon determining that the charging of the battery has been completed, control the main relay to turn off after all loads on the battery have been turned off to complete the charging control of the battery.

[0012] In some embodiments, the first-stage state parameters include: the output voltage of the DC-DC converter of the pure electric bus, the voltage of the BMS, the value of the status flag bit of the air conditioning high-voltage contactor of the pure electric bus, and the low-voltage of the main controller of the pure electric bus; the control unit determines, based on the first-stage state parameters, whether the overall state of the pure electric bus and the battery state are suitable for pre-charging the battery, including: determining whether the following conditions are met: the output voltage of the DC-DC converter of the pure electric bus is greater than a first set voltage, the voltage of the BMS is greater than a second set voltage, the value of the status flag bit of the air conditioning high-voltage contactor of the pure electric bus is a set flag value, and the low-voltage of the main controller of the pure electric bus is greater than a third set voltage; if these conditions are met, it is determined that the overall state of the pure electric bus and the battery state are suitable for pre-charging the battery.

[0013] In some embodiments, the second-stage state parameters include: the bus voltage of the main controller of the pure electric bus, the bus voltage of the compressor in the air conditioning system of the pure electric bus, and the establishment status of the communication connection between the main controller and the driver of the pure electric bus; the control unit, when pre-charging the battery, controls the auxiliary relay to be turned on for a first set time, and determines whether the pre-charging of the battery has been completed according to the second-stage state parameters, including: determining whether the following conditions are met: the bus voltage of the main controller of the pure electric bus drops, or the bus voltage of the compressor in the air conditioning system of the pure electric bus is less than a fourth set voltage and the bus voltage of the main controller of the pure electric bus is less than a fifth set voltage, or the establishment status of the communication connection between the main controller and the driver of the pure electric bus is that the communication connection has not been established; if not met, it is determined that the pre-charging of the battery has been completed; if met, it is determined that the pre-charging of the battery has not been completed.

[0014] In some embodiments, when the control unit is pre-charging the battery, after controlling the auxiliary relay to turn on for a first set time, it determines whether the pre-charging of the battery has been completed based on the second stage state parameters. The method further includes: if it is determined that the pre-charging of the battery has not been completed, delaying for a third set time before re-pre-charging the battery; and accumulating and counting the number of times the pre-charging of the battery has not been completed to obtain the number of pre-charging failures; if the number of pre-charging failures reaches a set number, then initiating a charging fault reminder message for the battery and ending the charging control of the battery.

[0015] In some embodiments, the third-stage state parameters include: the bus voltage of the driver of the pure electric bus, the command sent by the driver of the compressor in the air conditioning system of the pure electric bus to release the main relay, the bus voltage of the main controller of the pure electric bus, and the low-voltage of the main controller of the pure electric bus; the control unit, when charging the battery, determines whether the charging of the battery has been completed according to the third-stage state parameters, including: determining whether the following conditions are met: the pure electric bus... If the bus voltage of the bus's drive unit is less than the fifth preset voltage, or the bus voltage of the pure electric bus's drive unit experiences low-voltage protection, or a command to release the main relay is received from the driver of the compressor in the air conditioning unit of the pure electric bus, or the bus voltage of the main controller of the pure electric bus is less than the sixth preset voltage, or the low-voltage of the main controller of the pure electric bus is the seventh preset voltage; if these conditions are met, it is determined that the battery charging is complete; if not, it is determined that the battery charging is incomplete.

[0016] In conjunction with the above-mentioned device, the present invention further provides a pure electric bus, including: the control device for the pure electric bus described above.

[0017] In conjunction with the above method, the present invention further provides a storage medium comprising a stored program, wherein, when the program is executed, the device containing the storage medium controls the execution of the control method for the pure electric bus described above.

[0018] Therefore, the solution of this invention, when the pure electric bus receives a high-voltage request signal from the BMS, firstly performs a first-stage detection on the vehicle status and battery status to check whether the vehicle status and battery status meet preset battery pre-charging conditions. If the vehicle status and battery status meet the first-stage detection conditions, the auxiliary relay used to control battery pre-charging is activated, allowing the battery to pre-charge. After the battery has been pre-charging for a certain period of time, a second-stage detection is performed on the vehicle status and battery status to check whether the battery has completed pre-charging. If the vehicle status and battery status do not meet the second-stage detection conditions, it is considered that the battery has not completed pre-charging and the number of pre-charging failures has reached a set number, a charging fault is reported, and charging control is terminated. If the vehicle status and battery status meet the second-stage detection conditions... If the conditions are met, the battery is considered to have completed pre-charging. The main relay controlling battery charging is engaged for a certain period, and then the auxiliary relay controlling pre-charging opens, allowing the battery to begin charging. While the battery is charging, a third-stage detection is performed on the vehicle and battery states to determine if charging is complete. If the vehicle and battery states meet the third-stage detection conditions and all loads are off, the main relay controlling battery charging opens, confirming charging completion. If the vehicle and battery states do not meet the third-stage detection conditions, charging continues. Therefore, by first entering the pre-charging stage to detect pre-charging of the battery and vehicle when the vehicle receives the charging execution signal, and only proceeding with charging once the vehicle is determined to be in a rechargeable state, charging safety can be guaranteed.

[0019] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention.

[0020] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0021] Figure 1 This is a flowchart illustrating an embodiment of the control method for a pure electric bus of the present invention;

[0022] Figure 2 This is a flowchart illustrating an embodiment of the method of the present invention for determining whether it is suitable to precharge the battery based on the first-stage state parameters.

[0023] Figure 3 This is a flowchart illustrating an embodiment of the method of the present invention for determining whether the pre-charging of the battery is complete based on the second-stage state parameters;

[0024] Figure 4 This is a schematic flowchart of an embodiment of the method of the present invention in which the battery is precharged again after the precharge of the battery fails.

[0025] Figure 5 This is a flowchart illustrating an embodiment of the method of the present invention for determining whether battery charging is complete based on third-stage parameters.

[0026] Figure 6 This is a schematic diagram of the structure of an embodiment of the control device for a pure electric bus of the present invention;

[0027] Figure 7 This is a schematic diagram of the process of entering the pre-charging stage in an embodiment of the control method for a pure electric bus of the present invention;

[0028] Figure 8 This is a flowchart illustrating the pre-charge detection stage of an embodiment of the control method for a pure electric bus of the present invention.

[0029] Figure 9 This is a schematic flowchart illustrating the charging completion stage of an embodiment of the control method for a pure electric bus according to the present invention.

[0030] Referring to the accompanying drawings, the reference numerals in the embodiments of the present invention are as follows:

[0031] 102 - Control unit; 104 - Acquisition unit. Detailed Implementation

[0032] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below in conjunction with specific embodiments and corresponding drawings. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0033] Considering that charging via the high-voltage platform of the power battery involves inputting high-voltage electricity, when charging the battery of a pure electric bus, it is necessary to ensure that the entire vehicle is in a rechargeable state before charging can be performed through the high-voltage platform of the power battery.

[0034] However, during the charging process of the battery through the high-voltage platform of the power battery, if the entire vehicle is not in a rechargeable state before charging, it will seriously affect the safety of charging. Serious safety issues have occurred during actual charging processes, such as spontaneous combustion of buses during charging. Most of these incidents are due to certain components of the vehicle not being in a charging state before charging. Therefore, a pre-charging inspection of the entire vehicle is necessary to ensure that the entire vehicle is in a rechargeable state.

[0035] In some cases, when the vehicle starts charging before charging begins, some components may not yet be in a charging state, and may not receive signals or provide feedback. For example, the battery terminal may not receive a charging signal. In addition, if some components are not ready to charge during charging, the charging station will input high-voltage electricity, which may pose electrical safety issues.

[0036] Therefore, for pure electric buses that use batteries to power the vehicle, when the battery power is insufficient, the battery can be charged by a DC-DC converter from the high-voltage platform of the power battery, or by a fixed charging pile platform. To ensure charging safety and extend the service life of the vehicle and the battery, this invention proposes a charging control method for pure electric buses. When the vehicle receives the execution signal for charging the battery, it enters a pre-charging stage. Charging can only proceed after completing various pre-charging tests, thus ensuring charging safety and extending the service life of the battery and the vehicle.

[0037] According to an embodiment of the present invention, a control method for a pure electric bus is provided. The pure electric bus includes a battery and a BMS. A main relay for controlling the charging of the battery is provided at the battery location, and an auxiliary relay for controlling the pre-charging of the battery is also provided. The pre-charging stage is a stage preceding the charging stage. Before the battery is pre-charged, both the main relay and the auxiliary relay are in an open state. The control method for the pure electric bus is as follows: Figure 1 The diagram shows a flowchart of an embodiment of the method of the present invention. The control method for the pure electric bus may include steps S110 to S180.

[0038] In step S110, if the battery power is insufficient to meet the set power and the pure electric bus has arrived at the charging station, it is determined whether the high voltage request sent by the BMS has been received.

[0039] In step S120, if it is determined that the high voltage request sent by the BMS has been received, the vehicle status parameters of the pure electric bus are obtained. The vehicle status parameters of the pure electric bus include: the first stage status parameters before the pre-charging starts, the second stage status parameters after the pre-charging starts and before the charging starts, and the third stage status parameters after the charging starts and before the charging is completed.

[0040] In step S130, based on the first stage state parameters, the overall vehicle state of the pure electric bus and the battery state of the battery are determined to determine whether it is suitable to precharge the battery.

[0041] In step S140, if it is determined that the overall vehicle state of the pure electric bus and the battery state of the battery are suitable for pre-charging the battery, then the auxiliary relay is turned on to pre-charge the battery.

[0042] In some embodiments, the first-stage state parameters include: the output voltage of the DC-DC converter of the pure electric bus, the voltage of the BMS, the value of the status flag bit of the air conditioning high-voltage contactor of the pure electric bus, and the low-voltage of the main controller of the pure electric bus. In step S130, based on the first-stage state parameters, the specific process of determining whether the overall state of the pure electric bus and the battery state are suitable for pre-charging the battery is described below.

[0043] The following is combined Figure 2 The flowchart shown is a schematic diagram of an embodiment of the method of the present invention for determining whether it is suitable to precharge the battery based on the first stage state parameters. The specific process of determining whether the vehicle state of the pure electric bus and the battery state of the battery are suitable for precharging the battery based on the first stage state parameters in step S130 includes: steps S210 and S220.

[0044] Step S210: Determine whether the following conditions are met: the output voltage of the DC-DC converter of the pure electric bus is greater than the first set voltage, the voltage of the BMS is greater than the second set voltage, the value of the status flag bit of the air conditioning high-voltage contactor of the pure electric bus is a set flag value, and the low-voltage of the main controller of the pure electric bus is greater than the third set voltage; wherein, the first set voltage is such as 22V, the second set voltage is such as 450V, the third set voltage is such as 21V, and the set flag value is such as 1.

[0045] Step S220: If the conditions are met, it is determined that the overall vehicle state of the pure electric bus and the battery state of the battery are suitable for pre-charging the battery; otherwise, it is determined that the overall vehicle state of the pure electric bus and the battery state of the battery are not suitable for pre-charging the battery, and the charging control of the battery is turned off.

[0046] Specifically, Figure 7 This is a schematic diagram illustrating the process of entering the pre-charging stage in an embodiment of the control method for a pure electric bus according to the present invention. Figure 7 As shown, the control flow of the pre-charging stage in the control method for a pure electric bus proposed in this invention includes:

[0047] Step 11: Once the pure electric bus has received the high-voltage request signal (i.e., charging logic signal) sent by the BMS (Battery Management System), it enters the pre-charging start stage. During the pre-charging start stage, the vehicle status and battery status are first detected, i.e., the following first, second, third, and fourth conditions required to enter the pre-charging stage are determined. Based on the determination results, step 12 is executed.

[0048] First condition: Determine if the vehicle's DC-DC voltage is greater than 22V: If yes, proceed to step 12; otherwise, do not perform pre-charging.

[0049] The second condition is to determine whether the vehicle's BMS voltage is greater than 450V: if so, proceed to step 12; otherwise, do not perform pre-charging.

[0050] The third condition is to determine whether the status flag of the vehicle's air conditioning contactor is 1, that is, whether the high-voltage power supply between the air conditioner and the battery has been disconnected during charging: if so, proceed to step 12; otherwise, do not perform pre-charging.

[0051] Fourth condition: Determine if the main control low voltage is ≥21V: If yes, proceed to step 12; otherwise, do not perform pre-charging.

[0052] Step 12: If the first, second, third, and fourth conditions above are met simultaneously, the vehicle controls the battery to enter a pre-charge state for pre-charging, i.e., enters the pre-charge detection stage, which involves the activation of the auxiliary relay used to control the battery pre-charging. The auxiliary relay is located near the battery and is placed together with the main relay. The auxiliary relay assists the main relay, taking over its control function when the main relay is not working, and controlling the charging process.

[0053] In step S150, while the battery is being pre-charged, after controlling the auxiliary relay to turn on for a first set time, it is determined whether the pre-charging of the battery has been completed based on the second stage state parameters. The first set time is, for example, 2 seconds.

[0054] In step S160, after determining that the pre-charging of the battery has been completed, the main relay is turned on for a second set time, and then the auxiliary relay is turned off to charge the battery. The second set time is, for example, 2 seconds.

[0055] In step S170, while the battery is being charged, it is determined whether the charging of the battery has been completed based on the third stage state parameters.

[0056] In step S180, after determining that the charging of the battery is complete, the main relay is disconnected after all loads on the battery are turned off, thus completing the charging control of the battery.

[0057] This invention addresses the scenario where a pure electric bus uses a battery to power the entire vehicle. When the battery charge is insufficient, it can be charged via a DC-DC converter from a high-voltage power battery platform or via a fixed charging station. The proposed charging control method for a pure electric bus involves pre-charging both the vehicle and the battery before charging. This pre-charging test performs various checks, and charging only begins after all checks are passed. These checks are conducted throughout the entire pre-charging phase. By performing this pre-charging test before charging the battery, the system can detect whether the vehicle and battery are in a charging state, improving charging safety and extending the lifespan of both the battery and the vehicle.

[0058] Specifically, the present invention addresses the scenario where a pure electric bus uses a battery to power the entire vehicle. When the battery charge is insufficient, it can be charged via a DC-DC converter from a high-voltage power platform or via a fixed charging station. The proposed control method for a pure electric bus includes: when the main control screen of the pure electric bus displays insufficient battery power (e.g., below 20%), the pure electric bus should promptly return to a charging station. At this time, the entire vehicle has received a high-voltage request signal from the BMS (Battery Management System), indicating that the battery requires charging. When the pure electric bus connects to the charging station, the following three charging stages are executed sequentially to complete the charging of the battery: the first stage is the pre-charging stage; the second stage is the pre-charging detection stage; and the third stage is the charging completion stage. The high-voltage range for the high-voltage request is approximately 1000V. In this way, the high-voltage platform of the charging pile's power battery charges the battery through a DC-DC converter. When the pure electric bus receives a high-voltage request from the BMS (Battery Management System), the battery enters a pre-charge state. In the pre-charge state, various pre-charge tests are performed on the pure electric bus and the battery. Charging only begins after all the pre-charge tests on the pure electric bus and the battery are completed and the vehicle is in a rechargeable state. This ensures charging safety and helps extend the service life of the battery and the vehicle.

[0059] In some embodiments, the second-stage state parameters include: the bus voltage of the main controller of the pure electric bus, the bus voltage of the compressor in the air conditioning system of the pure electric bus, and the communication connection establishment status between the main controller and the driver of the pure electric bus. In step S150, when pre-charging the battery, after controlling the auxiliary relay to turn on for a first set time, the specific process of determining whether the pre-charging of the battery has been completed based on the second-stage state parameters is described in the following exemplary description.

[0060] The following is combined with Figure 3 The flowchart shown is a schematic diagram of an embodiment of the method of the present invention for determining whether the pre-charging of the battery is completed based on the second stage state parameters. It further illustrates the specific process of determining whether the pre-charging of the battery is completed based on the second stage state parameters after controlling the auxiliary relay to turn on for a first set time when the battery is pre-charging, in step S150, including steps S310 and S320.

[0061] Step S310: Determine whether the following conditions are met: the bus voltage of the main controller of the pure electric bus drops, or the bus voltage of the compressor in the air conditioner of the pure electric bus is less than the fourth set voltage and the bus voltage of the main controller of the pure electric bus is less than the fifth set voltage, or the communication connection between the main controller of the pure electric bus and the driver is not established; wherein, the fourth set voltage is such as 435V and the fifth set voltage is such as 425V.

[0062] Step S320: If the condition is not met, it is determined that the pre-charging of the battery has been completed; if the condition is met, it is determined that the pre-charging of the battery has not been completed.

[0063] Specifically, Figure 8 This is a flowchart illustrating the pre-charge detection stage of an embodiment of the control method for a pure electric bus according to the present invention. Figure 8 As shown, the control flow of the pre-charge detection stage in the control method for a pure electric bus proposed in this invention includes:

[0064] Step 21: When pre-charging begins 2 seconds after the auxiliary relay controlling battery pre-charging is activated, perform a pre-charging phase detection, i.e., enter the pre-charging detection phase. Determine the fifth, sixth, and seventh conditions required for entering the pre-charging detection phase, and proceed to step 22 based on the determination results. Note that pre-charging is both charging and a pre-charging detection; formal charging is charging after the main relay is activated.

[0065] The fifth condition is to determine whether the main control bus voltage has dropped. If so, proceed to step 22; otherwise, the auxiliary relay used to control battery pre-charging will pop open, pre-charging will fail, and pre-charging will restart after 1 minute, then return to step 21. The main control bus voltage signal can be fed back to the main controller. When the voltage represented by this signal is less than the set value, it is considered that the main control bus voltage has dropped.

[0066] The sixth condition is to determine whether the compressor bus voltage < 435V and the main control bus voltage < 425V are not met. If so, proceed to step 22; otherwise, the auxiliary relay used to control the pre-charging of the battery will pop up, the pre-charging will fail, and the pre-charging will restart after 1 minute, and return to step 21.

[0067] The seventh condition is to determine whether the main control module and drive module of the vehicle have not established communication. If so, proceed to step 22; otherwise, the auxiliary relay used to control the pre-charging of the battery will be deactivated, the pre-charging will fail, and the pre-charging will restart after 1 minute, and the process will return to step 21.

[0068] Step 22: If the fifth, sixth, and seventh conditions are not met simultaneously, it indicates that the battery has completed pre-charging, and the battery is then controlled to enter the charging state.

[0069] In step 22, the process of step 21 is continuously monitored for 2 seconds. If any of the three conditions (i.e., the fifth, sixth, and seventh conditions) are met, the auxiliary relay used to control the pre-charging of the battery is deactivated, indicating a pre-charging failure. If the three conditions are not met, the main relay used to control the charging of the battery is activated after 2 seconds. After the main relay is activated for 2 seconds, the auxiliary relay used to control the pre-charging of the battery is deactivated, and charging begins.

[0070] In some embodiments, at step S150, when the battery is being precharged, after controlling the auxiliary relay to turn on for a first set time, it is determined whether the precharging of the battery has been completed according to the second stage state parameters. The method further includes a control process for re-precharging the battery if the precharging fails.

[0071] The following is combined Figure 4 The flowchart shown is a schematic diagram of an embodiment of the method of the present invention in which the battery pre-charging fails and then pre-charging is performed again. It further illustrates the control process of pre-charging again in step S150 when the battery pre-charging fails, including steps S410 and S420.

[0072] Step S410: After determining that the pre-charging of the battery has not been completed, the battery is pre-charged again after a third set time; and the number of times the pre-charging of the battery has not been completed is accumulated to obtain the number of pre-charging failures; wherein, the third set time is, for example, 1 minute.

[0073] Step S420: If the number of pre-charge failures reaches a set number, a reminder message for the charging failure of the battery is initiated, and the charging control of the battery is terminated.

[0074] Specifically, such as Figure 8 As shown, the control flow of the pre-charge detection stage in the control method for pure electric buses proposed in this invention includes: continuously detecting for 2 seconds in step 21; if any of the above three conditions (i.e., the fifth, sixth, and seventh conditions) are met, the auxiliary relay used to control the pre-charge of the battery is deactivated, indicating a pre-charge failure; pre-charge is restarted after 1 minute. The number of pre-charge attempts is accumulated; if two pre-charge failures occur, a charging fault is reported, and charging control is terminated.

[0075] In some embodiments, the third-stage state parameters include: the bus voltage of the driver of the pure electric bus, the command sent by the driver of the compressor in the air conditioning system of the pure electric bus to release the main relay, the bus voltage of the main controller of the pure electric bus, and the low-voltage of the main controller of the pure electric bus. In step S170, when the battery is being charged, the specific process of determining whether the charging of the battery has been completed based on the third-stage state parameters is described in the following exemplary description.

[0076] The following is combined Figure 5 The flowchart shown is a schematic diagram of an embodiment of the method of the present invention for determining whether the charging of the battery is completed based on the third stage parameters. It further illustrates the specific process of determining whether the charging of the battery is completed based on the third stage state parameters when the battery is being charged in step S170, including steps S510 and S520.

[0077] Step S510: Determine whether the following conditions are met: the bus voltage of the driver of the pure electric bus is less than the fifth set voltage, or the bus voltage of the driver of the pure electric bus is under-voltage protected, or a command to release the main relay is received from the driver of the compressor in the air conditioner of the pure electric bus, or the bus voltage of the main controller of the pure electric bus is less than the sixth set voltage, or the low voltage of the main controller of the pure electric bus is the seventh set voltage; wherein, the seventh set voltage is, for example, 24V.

[0078] Step S520: If the condition is met, it is determined that the charging of the battery is complete; if the condition is not met, it is determined that the charging of the battery is incomplete.

[0079] Specifically, Figure 9 This is a schematic flowchart illustrating the charging completion stage of an embodiment of the control method for a pure electric bus according to the present invention. Figure 9 As shown, the control flow of the charging completion stage in the control method for a pure electric bus proposed in this invention includes:

[0080] Step 31: After the main relay is energized for 2 seconds and the auxiliary relay for controlling the pre-charging of the battery has been released and charging has begun, the control for the charging completion stage is initiated. Specifically, the following conditions (eighth, ninth, tenth, eleventh, and twelfth) required for entering the pre-charging completion stage are judged, and step 32 is executed based on the judgment results.

[0081] The eighth condition is to determine whether the drive bus voltage is <435V: if yes, proceed to step 32; otherwise, determine the next condition to continue charging.

[0082] Ninth condition: Determine whether the command to release the relay sent by the compressor driver is received. If yes, proceed to step 32; otherwise, continue charging.

[0083] The tenth condition is to determine whether the main control voltage is 24V, i.e., the main control voltage is too low. If so, proceed to step 32; otherwise, continue charging.

[0084] The eleventh condition is to determine whether the main control bus voltage is <425V: if yes, proceed to step 32; otherwise, continue charging.

[0085] The twelfth condition is to determine whether the bus voltage undervoltage protection is met: if yes, proceed to step 32; otherwise, continue charging.

[0086] Step 32: If any one of the above conditions 8, 9, 10, 11, and 12 is met, and all loads are turned off, the main relay used to control battery charging will pop open, then charging is confirmed to be complete.

[0087] The above-mentioned control measures for the pre-charge stage, the pre-charge detection stage, and the charging completion stage ensure charging safety and extend battery life throughout the entire charging process.

[0088] In the present invention, a control method for pre-charge detection during the charging of a pure electric bus is proposed. After the vehicle receives the execution signal for charging the battery, it first enters the pre-charge stage, in which the vehicle and the battery are checked before charging. The battery is then charged only after all the pre-charge detections of the vehicle and the battery are completed in the pre-charge stage, so as to ensure the safety of charging and extend the service life of the battery and the vehicle.

[0089] The technical solution of this embodiment involves first detecting the vehicle status and battery status when the pure electric bus receives a high-voltage request signal from the BMS. This detection checks whether the vehicle status and battery status meet preset battery pre-charging conditions. If they do, an auxiliary relay controlling battery pre-charging is activated, initiating pre-charging. After a certain pre-charging period, a second detection is performed to check if pre-charging is complete. If the vehicle status and battery status do not meet the second detection conditions, pre-charging is considered incomplete, the number of pre-charging failures reaches a set number, a charging fault is reported, and charging control ends. If the vehicle status and battery status meet the second detection conditions, the second detection is performed. If the pre-charging conditions are met, the battery is considered to have completed pre-charging. The main relay controlling battery charging then engages for a certain period, after which the auxiliary relay controlling pre-charging opens, allowing the battery to begin charging. While the battery is charging, a third-stage detection is performed on the vehicle and battery states to determine if charging is complete. If the vehicle and battery states meet the third-stage detection conditions and all loads are off, the main relay controlling battery charging opens, confirming charging completion. If the vehicle and battery states do not meet the third-stage detection conditions, charging continues. Therefore, by first entering the pre-charging stage to detect pre-charging of the battery and vehicle when the vehicle receives the charging execution signal, and only proceeding with charging once the vehicle is determined to be in a rechargeable state, charging safety can be guaranteed.

[0090] According to an embodiment of the present invention, a control device for a pure electric bus corresponding to a control method for a pure electric bus is also provided. The pure electric bus includes a battery and a BMS; a main relay for controlling the charging of the battery is provided at the battery location, and an auxiliary relay for controlling the pre-charging of the battery is also provided; the pre-charging stage is a stage preceding the charging stage; before the battery is pre-charged, both the main relay and the auxiliary relay are in an open state; the control device for the pure electric bus is described below. Figure 6 The diagram shows a structural schematic of an embodiment of the device of the present invention. The control device for the pure electric bus may include: a control unit 102 and an acquisition unit 104.

[0091] The control unit 102 is configured to determine whether a high-voltage request has been received from the BMS when the battery power is insufficient and the electric bus has arrived at a charging station. The specific functions and processing of this control unit 102 are described in step S110.

[0092] The acquisition unit 104 is configured to acquire the vehicle status parameters of the pure electric bus if it is determined that a high-voltage request sent by the BMS has been received. The vehicle status parameters of the pure electric bus include: a first-stage status parameter before pre-charging begins, a second-stage status parameter after pre-charging begins and before charging begins, and a third-stage status parameter after charging begins and before charging is completed. For the specific functions and processing of the acquisition unit 104, please refer to step S120.

[0093] The control unit 102 is further configured to determine, based on the first stage state parameters, the overall vehicle state of the pure electric bus and the battery state of the battery, whether it is suitable to pre-charge the battery. The specific functions and processing of this control unit 102 are described in step S130.

[0094] The control unit 102 is further configured to, if it is determined that the overall vehicle state of the pure electric bus and the battery state are suitable for pre-charging the battery, control the auxiliary relay to turn on to pre-charge the battery. The specific functions and processing of this control unit 102 are described in step S140.

[0095] In some implementations, the first stage state parameters include: the output voltage of the DC-DC converter of the pure electric bus, the voltage of the BMS, the value of the status flag bit of the air conditioning high-voltage contactor of the pure electric bus, and the low-voltage of the main controller of the pure electric bus.

[0096] The control unit 102, based on the first stage state parameters, determines whether the overall vehicle state of the pure electric bus and the battery state of the battery are suitable for pre-charging the battery, including:

[0097] The control unit 102 is further configured to determine whether the following conditions are met: the output voltage of the DC-DC converter of the pure electric bus is greater than a first set voltage; the voltage of the BMS is greater than a second set voltage; the value of the status flag bit of the air conditioning high-voltage contactor of the pure electric bus is a set flag value; and the low-voltage of the main controller of the pure electric bus is greater than a third set voltage; wherein, the first set voltage is, for example, 22V; the second set voltage is, for example, 450V; the third set voltage is, for example, 21V; and the set flag value is, for example, 1. The specific functions and processing of this control unit 102 are described in step S210.

[0098] The control unit 102 is further configured to, if a condition is met, determine that the overall vehicle state of the pure electric bus and the battery state of the battery are suitable for pre-charging the battery; otherwise, determine that the overall vehicle state of the pure electric bus and the battery state of the battery are not suitable for pre-charging the battery, and then disable the charging control for the battery. The specific functions and processing of this control unit 102 are described in step S220.

[0099] Specifically, Figure 7 This is a schematic diagram illustrating the process of entering the pre-charging stage in an embodiment of the control method for a pure electric bus according to the present invention. Figure 7 As shown, the control flow of the pre-charging stage in the control method for a pure electric bus proposed in this invention includes:

[0100] Step 11: Once the pure electric bus has received the high-voltage request signal (i.e., charging logic signal) sent by the BMS (Battery Management System), it enters the pre-charging start stage. During the pre-charging start stage, the vehicle status and battery status are first detected, i.e., the following first, second, third, and fourth conditions required to enter the pre-charging stage are determined. Based on the determination results, step 12 is executed.

[0101] First condition: Determine if the vehicle's DC-DC voltage is greater than 22V: If yes, proceed to step 12; otherwise, do not perform pre-charging.

[0102] The second condition is to determine whether the vehicle's BMS voltage is greater than 450V: if so, proceed to step 12; otherwise, do not perform pre-charging.

[0103] The third condition is to determine whether the status flag of the vehicle's air conditioning contactor is 1, that is, whether the high-voltage power supply between the air conditioner and the battery has been disconnected during charging: if so, proceed to step 12; otherwise, do not perform pre-charging.

[0104] Fourth condition: Determine if the main control low voltage is ≥21V: If yes, proceed to step 12; otherwise, do not perform pre-charging.

[0105] Step 12: If the first, second, third, and fourth conditions above are met simultaneously, the vehicle controls the battery to enter a pre-charge state for pre-charging, i.e., enters the pre-charge detection stage, which involves the activation of the auxiliary relay used to control the battery pre-charging. The auxiliary relay is located near the battery and is placed together with the main relay. The auxiliary relay assists the main relay, taking over its control function when the main relay is not working, and controlling the charging process.

[0106] The control unit 102 is further configured to, when pre-charging the battery, control the auxiliary relay to turn on for a first set time, and then determine, based on the second stage state parameters, whether the pre-charging of the battery has been completed. The first set time is, for example, 2 seconds. The specific functions and processing of this control unit 102 are described in step S150.

[0107] The control unit 102 is further configured to, upon determining that the pre-charging of the battery has been completed, control the main relay to turn on for a second preset time, and then control the auxiliary relay to turn off to charge the battery; wherein the second preset time is, for example, 2 seconds. The specific functions and processing of this control unit 102 are described in step S160.

[0108] The control unit 102 is further configured to determine, based on the third-stage state parameters, whether the charging of the battery has been completed while the battery is being charged. The specific functions and processing of this control unit 102 are described in step S170.

[0109] The control unit 102 is further configured to, upon determining that the charging of the battery is complete, control the main relay to disconnect after all loads on the battery are turned off, thereby completing the charging control of the battery. The specific functions and processing of this control unit 102 are described in step S180.

[0110] This invention addresses the scenario where a pure electric bus uses a battery to power the entire vehicle. When the battery charge is insufficient, it can be charged via a DC-DC converter from a high-voltage power battery platform or via a fixed charging station. The proposed charging control device for this pure electric bus performs a pre-charge test on both the vehicle and the battery before charging. This pre-charge test involves various checks, and charging only begins after all checks are passed. These checks are performed on both the vehicle and the battery throughout the entire pre-charge phase. This pre-charge test, which checks whether the vehicle and battery are in a charging state before charging, improves charging safety and extends the lifespan of both the battery and the vehicle.

[0111] Specifically, the present invention addresses the scenario where a pure electric bus uses a battery to power the entire vehicle. When the battery power is insufficient, it can be charged via a DC-DC converter from a high-voltage power platform or via a fixed charging pile platform. The proposed control device for this pure electric bus includes: when the main control screen of the pure electric bus displays insufficient battery power (e.g., below 20%), the pure electric bus should promptly return to a charging station. At this time, the pure electric bus has received a high-voltage request signal from the BMS (Battery Management System), indicating that the battery requires charging. When the pure electric bus connects to the charging pile, the following three charging stages are executed sequentially to complete the charging of the battery: the first stage is the pre-charging stage; the second stage is the pre-charging detection stage; and the third stage is the charging completion stage. The high-voltage range for the high-voltage request is approximately 1000V. In this way, the high-voltage platform of the charging pile's power battery charges the battery through a DC-DC converter. When the pure electric bus receives a high-voltage request from the BMS (Battery Management System), the battery enters a pre-charge state. In the pre-charge state, various pre-charge tests are performed on the pure electric bus and the battery. Charging only begins after all the pre-charge tests on the pure electric bus and the battery are completed and the vehicle is in a rechargeable state. This ensures charging safety and helps extend the service life of the battery and the vehicle.

[0112] In some implementations, the second-stage state parameters include: the bus voltage of the main controller of the pure electric bus, the bus voltage of the compressor in the air conditioning system of the pure electric bus, and the establishment status of the communication connection between the main controller and the driver of the pure electric bus.

[0113] When the battery is being pre-charged, the control unit 102, after controlling the auxiliary relay to turn on for a first set time, determines whether the pre-charging of the battery has been completed based on the second stage state parameters, including:

[0114] The control unit 102 is further configured to determine whether the following conditions are met: the bus voltage of the main controller of the pure electric bus drops, or the bus voltage of the compressor in the air conditioning system of the pure electric bus is less than a fourth set voltage and the bus voltage of the main controller of the pure electric bus is less than a fifth set voltage, or the communication connection between the main controller of the pure electric bus and the driver is not established; wherein, the fourth set voltage is, for example, 435V, and the fifth set voltage is, for example, 425V. The specific functions and processing of this control unit 102 are described in step S310.

[0115] The control unit 102 is further configured to determine that the pre-charging of the battery is complete if the condition is not met, and to determine that the pre-charging of the battery is incomplete if the condition is met. The specific functions and processing of this control unit 102 are described in step S320.

[0116] Specifically, Figure 8 This is a flowchart illustrating the pre-charge detection stage of an embodiment of the control method for a pure electric bus according to the present invention. Figure 8 As shown, the control flow of the pre-charge detection stage in the control method for a pure electric bus proposed in this invention includes:

[0117] Step 21: When pre-charging begins 2 seconds after the auxiliary relay controlling battery pre-charging is activated, perform a pre-charging phase detection, i.e., enter the pre-charging detection phase. Determine the fifth, sixth, and seventh conditions required for entering the pre-charging detection phase, and proceed to step 22 based on the determination results. Note that pre-charging is both charging and a pre-charging detection; formal charging is charging after the main relay is activated.

[0118] The fifth condition is to determine whether the main control bus voltage has dropped. If so, proceed to step 22; otherwise, the auxiliary relay used to control battery pre-charging will pop open, pre-charging will fail, and pre-charging will restart after 1 minute, then return to step 21. The main control bus voltage signal can be fed back to the main controller. When the voltage represented by this signal is less than the set value, it is considered that the main control bus voltage has dropped.

[0119] The sixth condition is to determine whether the compressor bus voltage < 435V and the main control bus voltage < 425V are not met. If so, proceed to step 22; otherwise, the auxiliary relay used to control the pre-charging of the battery will pop up, the pre-charging will fail, and the pre-charging will restart after 1 minute, and return to step 21.

[0120] The seventh condition is to determine whether the main control module and drive module of the vehicle have not established communication. If so, proceed to step 22; otherwise, the auxiliary relay used to control the pre-charging of the battery will be deactivated, the pre-charging will fail, and the pre-charging will restart after 1 minute, and the process will return to step 21.

[0121] Step 22: If the fifth, sixth, and seventh conditions are not met simultaneously, it indicates that the battery has completed pre-charging, and the battery is then controlled to enter the charging state.

[0122] In step 22, the process of step 21 is continuously monitored for 2 seconds. If any of the three conditions (i.e., the fifth, sixth, and seventh conditions) are met, the auxiliary relay used to control the pre-charging of the battery is deactivated, indicating a pre-charging failure. If the three conditions are not met, the main relay used to control the charging of the battery is activated after 2 seconds. After the main relay is activated for 2 seconds, the auxiliary relay used to control the pre-charging of the battery is deactivated, and charging begins.

[0123] In some embodiments, when the control unit 102 is pre-charging the battery, after controlling the auxiliary relay to turn on for a first set time, it determines whether the pre-charging of the battery has been completed based on the second stage state parameters, and further includes a control process for re-pre-charging the battery if the pre-charging fails.

[0124] The control unit 102 is further configured to, upon determining that the pre-charging of the battery has not been completed, delay for a third preset time before re-pre-charging the battery; and to cumulatively count the number of times the pre-charging of the battery has failed to complete, thereby obtaining the number of pre-charging failures; wherein the third preset time is, for example, 1 minute. The specific functions and processing of this control unit 102 are described in step S410.

[0125] The control unit 102 is further configured to, if the number of pre-charge failures reaches a set number, initiate a charging fault reminder message for the battery and terminate the charging control of the battery. The specific functions and processing of this control unit 102 are described in step S420.

[0126] Specifically, such as Figure 8 As shown, the control flow of the pre-charge detection stage in the control device of the pure electric bus proposed in this invention includes: continuously detecting step 21 for 2 seconds; if any of the above three conditions (i.e., the fifth, sixth, and seventh conditions) are met, the auxiliary relay used to control the pre-charge of the battery is deactivated, indicating a pre-charge failure; pre-charge is restarted after 1 minute. The number of pre-charge attempts is accumulated; if two pre-charge failures occur, a charging fault is reported, and charging control is terminated.

[0127] In some implementations, the third-stage state parameters include: the bus voltage of the driver of the pure electric bus, the command sent by the driver of the compressor in the air conditioning system of the pure electric bus to release the main relay, the bus voltage of the main controller of the pure electric bus, and the low-voltage of the main controller of the pure electric bus.

[0128] The control unit 102, when charging the battery, determines whether the charging of the battery has been completed based on the third-stage state parameters, including:

[0129] The control unit 102 is further configured to determine whether the following conditions are met: the bus voltage of the driver of the pure electric bus is less than a fifth preset voltage, or the bus voltage of the driver of the pure electric bus experiences low-voltage protection, or a command to release the main relay is received from the driver of the compressor in the air conditioning system of the pure electric bus, or the bus voltage of the main controller of the pure electric bus is less than a sixth preset voltage, or the low-voltage of the main controller of the pure electric bus is a seventh preset voltage. The seventh preset voltage is, for example, 24V. The specific functions and processing of this control unit 102 are described in step S510.

[0130] The control unit 102 is further configured to determine that the charging of the battery is complete if the condition is met, and to determine that the charging of the battery is incomplete if the condition is not met. The specific functions and processing of the control unit 102 are described in step S520.

[0131] Specifically, Figure 9 This is a schematic flowchart illustrating the charging completion stage of an embodiment of the control method for a pure electric bus according to the present invention. Figure 9 As shown, the control flow of the charging completion stage in the control method for a pure electric bus proposed in this invention includes:

[0132] Step 31: After the main relay is energized for 2 seconds and the auxiliary relay for controlling the pre-charging of the battery has been released and charging has begun, the control for the charging completion stage is initiated. Specifically, the following conditions (eighth, ninth, tenth, eleventh, and twelfth) required for entering the pre-charging completion stage are judged, and step 32 is executed based on the judgment results.

[0133] The eighth condition is to determine whether the drive bus voltage is <435V: if yes, proceed to step 32; otherwise, determine the next condition to continue charging.

[0134] Ninth condition: Determine whether the command to release the relay sent by the compressor driver is received. If yes, proceed to step 32; otherwise, continue charging.

[0135] The tenth condition is to determine whether the main control voltage is 24V, i.e., the main control voltage is too low. If so, proceed to step 32; otherwise, continue charging.

[0136] The eleventh condition is to determine whether the main control bus voltage is <425V: if yes, proceed to step 32; otherwise, continue charging.

[0137] The twelfth condition is to determine whether the bus voltage undervoltage protection is met: if yes, proceed to step 32; otherwise, continue charging.

[0138] Step 32: If any one of the above conditions 8, 9, 10, 11, and 12 is met, and all loads are turned off, the main relay used to control battery charging will pop open, then charging is confirmed to be complete.

[0139] The above-mentioned control measures for the pre-charge stage, the pre-charge detection stage, and the charging completion stage ensure charging safety and extend battery life throughout the entire charging process.

[0140] In the present invention, a control method for pre-charge detection during the charging of a pure electric bus is proposed. After the vehicle receives the execution signal for charging the battery, it first enters the pre-charge stage, in which the vehicle and the battery are checked before charging. The battery is then charged only after all the pre-charge detections of the vehicle and the battery are completed in the pre-charge stage, so as to ensure the safety of charging and extend the service life of the battery and the vehicle.

[0141] Since the processing and functions implemented by the device in this embodiment are basically the same as the embodiments, principles and examples of the aforementioned methods, any details not covered in the description of this embodiment can be found in the relevant descriptions in the aforementioned embodiments, and will not be repeated here.

[0142] The technical solution of this invention involves first detecting the vehicle status and battery status when the pure electric bus receives a high-voltage request signal from the BMS. This detection checks whether the vehicle status and battery status meet preset battery pre-charging conditions. If they do, an auxiliary relay controlling battery pre-charging is activated, initiating pre-charging. After a certain pre-charging period, a second detection is performed to check if the battery pre-charging is complete. If the vehicle status and battery status do not meet the second detection conditions, the battery is considered not to have completed pre-charging, and the number of pre-charging failures reaches a set number. A charging fault is reported, and charging control is terminated. If the battery status meets the second-stage detection conditions, the battery is considered to have completed pre-charging. The main relay controlling battery charging then engages for a certain period, while the auxiliary relay controlling pre-charging opens, allowing the battery to begin charging. During battery charging, a third-stage detection is performed on the vehicle and battery status to determine if charging is complete. If both the vehicle and battery status meet the third-stage detection conditions, and all loads are off, the main relay controlling battery charging opens, confirming charging completion. If the vehicle and battery status do not meet the third-stage detection conditions, charging continues. By ensuring the vehicle is in a rechargeable state before charging, charging safety is guaranteed, which helps extend the lifespan of both the battery and the vehicle.

[0143] According to an embodiment of the present invention, a pure electric bus corresponding to a control device for a pure electric bus is also provided. This pure electric bus may include the control device for a pure electric bus described above.

[0144] Since the processing and functions implemented by the pure electric bus in this embodiment are basically the same as the embodiments, principles and examples of the aforementioned device, any details not covered in the description of this embodiment can be found in the relevant descriptions in the aforementioned embodiments, and will not be repeated here.

[0145] The technical solution of this invention involves first detecting the vehicle status and battery status when the pure electric bus receives a high-voltage request signal from the BMS. This detection checks whether the vehicle status and battery status meet preset battery pre-charging conditions. If they do, an auxiliary relay controlling battery pre-charging is activated, initiating pre-charging. After a certain pre-charging period, a second detection is performed to check if the battery pre-charging is complete. If the vehicle status and battery status do not meet the second detection conditions, the battery is considered not to have completed pre-charging, and the number of pre-charging failures reaches a set number. A charging fault is reported, and charging control ends. If the vehicle status and battery status meet the second detection conditions, the second detection is performed. If the second-stage testing conditions are met, the battery is considered to have completed pre-charging. The main relay controlling battery charging is engaged for a certain period, and then the auxiliary relay controlling pre-charging opens, allowing the battery to begin charging. While the battery is charging, a third-stage test is performed on the vehicle and battery status to determine if charging is complete. If the vehicle and battery status meet the third-stage testing conditions and all loads are closed, the main relay controlling battery charging opens, confirming charging completion. If the vehicle and battery status do not meet the third-stage testing conditions, charging continues. By completing various pre-charging tests on the vehicle and battery during the pre-charging stage before charging, charging safety is ensured, and the lifespan of the battery and vehicle is extended.

[0146] According to an embodiment of the present invention, a storage medium corresponding to a control method for a pure electric bus is also provided. The storage medium includes a stored program, wherein the program controls the device where the storage medium is located to execute the control method for the pure electric bus described above when it is running.

[0147] Since the processing and functions implemented by the storage medium in this embodiment are basically the same as the embodiments, principles and examples of the aforementioned methods, any details not covered in this embodiment can be found in the relevant descriptions in the aforementioned embodiments, and will not be repeated here.

[0148] The technical solution of this invention involves first detecting the vehicle status and battery status when the pure electric bus receives a high-voltage request signal from the BMS. This detection checks whether the vehicle status and battery status meet preset battery pre-charging conditions. If they do, an auxiliary relay controlling battery pre-charging is activated, initiating pre-charging. After a certain pre-charging period, a second detection is performed to check if the battery pre-charging is complete. If the vehicle status and battery status do not meet the second detection conditions, the battery is considered not to have completed pre-charging, and the number of pre-charging failures reaches a set number. A charging fault is reported, and charging control ends. If the vehicle status and battery status meet the second detection conditions, the battery is considered to have completed pre-charging. In the pre-charging process, after the main relay controlling battery charging is engaged for a certain period, the auxiliary relay controlling battery pre-charging opens, allowing the battery to begin charging. While the battery is charging, a third-stage detection is performed on the vehicle and battery status to determine if charging is complete. If the vehicle and battery status meet the third-stage detection conditions and all loads are off, the main relay controlling battery charging opens, confirming charging completion. If the vehicle and battery status do not meet the third-stage detection conditions, charging continues. By performing various pre-charging tests on the pure electric bus and its battery, and ensuring the vehicle is in a rechargeable state before charging begins, charging safety is guaranteed, and the lifespan of the battery and the vehicle is extended.

[0149] In summary, it is readily understood by those skilled in the art that, without conflict, the aforementioned advantageous methods can be freely combined and superimposed.

[0150] The above description is merely an embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the invention by those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the invention should be included within the scope of the claims.

Claims

1. A control method for a pure electric bus, characterized in that, The pure electric bus has a battery and a BMS; at the battery location, a main relay for controlling the charging of the battery is provided, and an auxiliary relay for controlling the pre-charging of the battery is also provided; the pre-charging is a stage for pre-charging detection of the battery and the whole vehicle, and is a stage before the charging stage. The pre-charging detection is used to determine whether the whole vehicle and the battery are in a rechargeable state; charging in a rechargeable state can ensure the safety of charging; Before the battery is pre-charged, both the main relay and the auxiliary relay are in the off state; The control method for the pure electric bus includes: If the battery power is less than the set power and the pure electric bus has arrived at the charging station, determine whether the high voltage request sent by the BMS has been received. If it is determined that the high voltage request sent by the BMS has been received, the vehicle status parameters of the pure electric bus are obtained; the vehicle status parameters of the pure electric bus include: the first stage status parameters before the pre-charging starts, the second stage status parameters after the pre-charging starts and before the charging starts, and the third stage status parameters after the charging starts and before the charging is completed. Based on the state parameters of the first stage, determine the overall state of the pure electric bus and the state of the battery, and whether it is suitable to precharge the battery. If it is determined that the overall condition of the pure electric bus and the condition of the battery are suitable for pre-charging the battery, then the auxiliary relay is turned on to pre-charge the battery. When the battery is pre-charged, after the auxiliary relay is turned on for a first set time, it is determined whether the pre-charging of the battery has been completed according to the second stage state parameters. Once it is determined that the pre-charging of the battery is complete, the main relay is turned on for a second set time, and then the auxiliary relay is turned off to charge the battery. When the battery is being charged, it is determined whether the charging of the battery has been completed based on the third stage state parameters. Once it is determined that the charging of the battery is complete, the main relay is disconnected after all loads on the battery are turned off, thus completing the charging control of the battery.

2. The control method for a pure electric bus according to claim 1, characterized in that, The first stage state parameters include: the output voltage of the DC-DC converter of the pure electric bus, the voltage of the BMS, the value of the status flag bit of the air conditioning high-voltage contactor of the pure electric bus, and the low-voltage of the main controller of the pure electric bus. Based on the state parameters of the first stage, determine the overall vehicle state of the pure electric bus and the battery state of the battery, and whether it is suitable to pre-charge the battery, including: Determine whether the following conditions are met: the output voltage of the DC-DC converter of the pure electric bus is greater than the first set voltage, the voltage of the BMS is greater than the second set voltage, the value of the status flag bit of the air conditioning high-voltage contactor of the pure electric bus is the set flag value, and the low-voltage of the main controller of the pure electric bus is greater than the third set voltage. If the conditions are met, then the overall condition of the pure electric bus and the battery condition are determined to be suitable for pre-charging the battery.

3. The control method for a pure electric bus according to claim 1, characterized in that, The second stage status parameters include: the bus voltage of the main controller of the pure electric bus, the bus voltage of the compressor in the air conditioning system of the pure electric bus, and the communication connection establishment status between the main controller and the driver of the pure electric bus. When pre-charging the battery, after controlling the auxiliary relay to turn on for a first set time, determine whether the pre-charging of the battery has been completed based on the second stage state parameters, including: Determine whether the following conditions are met: the bus voltage of the main controller of the pure electric bus drops, or the bus voltage of the compressor in the air conditioner of the pure electric bus is less than the fourth set voltage and the bus voltage of the main controller of the pure electric bus is less than the fifth set voltage, or the communication connection between the main controller of the pure electric bus and the driver is not established. If the condition is not met, it is determined that the pre-charging of the battery has been completed; if the condition is met, it is determined that the pre-charging of the battery has not been completed.

4. The control method for a pure electric bus according to claim 3, characterized in that, When pre-charging the battery, after controlling the auxiliary relay to turn on for a first set time, determining whether the pre-charging of the battery has been completed based on the second stage state parameters further includes: If it is determined that the pre-charging of the battery has not been completed, the battery is pre-charged again after a third set time delay; and the number of times the pre-charging of the battery has not been completed is accumulated to obtain the number of pre-charging failures. If the number of pre-charge failures reaches a set number, a charging fault reminder message for the battery is initiated, and the charging control of the battery is terminated.

5. The control method for a pure electric bus according to any one of claims 1 to 4, characterized in that, The third-stage state parameters include: the bus voltage of the driver of the pure electric bus, the command sent by the driver of the compressor in the air conditioner of the pure electric bus to release the main relay, the bus voltage of the main controller of the pure electric bus, and the low voltage of the main controller of the pure electric bus. When charging the battery, determining whether charging of the battery is complete based on the third-stage state parameters includes: Determine whether the following conditions are met: the bus voltage of the driver of the pure electric bus is less than the fifth set voltage, or the bus voltage of the driver of the pure electric bus is under-voltage protection, or a command to release the main relay is received from the driver of the compressor in the air conditioner of the pure electric bus, or the bus voltage of the main controller of the pure electric bus is less than the sixth set voltage, or the low voltage of the main controller of the pure electric bus is the seventh set voltage; If the condition is met, the battery charging is determined to be complete; if the condition is not met, the battery charging is determined to be incomplete.

6. A control device for a pure electric bus, characterized in that, The pure electric bus has a battery and a BMS; at the battery location, a main relay for controlling the charging of the battery is provided, and an auxiliary relay for controlling the pre-charging of the battery is also provided; the pre-charging is a stage for pre-charging detection of the battery and the whole vehicle, and is a stage before the charging stage. The pre-charging detection is used to determine whether the whole vehicle and the battery are in a rechargeable state; charging in a rechargeable state can ensure the safety of charging; Before the battery is pre-charged, both the main relay and the auxiliary relay are in the off state; The control device for the pure electric bus includes: The control unit is configured to determine whether a high-voltage request has been received from the BMS when the battery power is less than a set power and the pure electric bus has arrived at a charging station. The acquisition unit is configured to acquire the vehicle status parameters of the pure electric bus if it is determined that a high voltage request sent by the BMS has been received; the vehicle status parameters of the pure electric bus include: a first stage status parameter before pre-charging starts, a second stage status parameter after pre-charging starts and before charging starts, and a third stage status parameter after charging starts and before charging is completed. The control unit is further configured to determine, based on the first stage state parameters, the overall vehicle state of the pure electric bus and the battery state of the battery, and whether it is suitable to precharge the battery. The control unit is further configured to, if it is determined that the overall vehicle state of the pure electric bus and the battery state of the battery are suitable for precharging the battery, control the auxiliary relay to turn on to precharge the battery. The control unit is further configured to, when precharging the battery, control the auxiliary relay to turn on for a first set time, and then determine, based on the second stage state parameters, whether the precharging of the battery has been completed. The control unit is further configured to, upon determining that the pre-charging of the battery has been completed, control the main relay to turn on for a second predetermined time, and then control the auxiliary relay to turn off to charge the battery. The control unit is further configured to determine, based on the third-stage state parameters, whether the charging of the battery has been completed when the battery is being charged. The control unit is further configured to, upon determining that the charging of the battery is complete, control the main relay to disconnect after all loads on the battery are turned off, thereby completing the charging control of the battery.

7. The control device for a pure electric bus according to claim 6, characterized in that, The first stage state parameters include: the output voltage of the DC-DC converter of the pure electric bus, the voltage of the BMS, the value of the status flag bit of the air conditioning high-voltage contactor of the pure electric bus, and the low-voltage of the main controller of the pure electric bus. The control unit, based on the first-stage state parameters, determines whether the overall vehicle state of the pure electric bus and the battery state of the battery are suitable for pre-charging the battery, including: Determine whether the following conditions are met: the output voltage of the DC-DC converter of the pure electric bus is greater than the first set voltage, the voltage of the BMS is greater than the second set voltage, the value of the status flag bit of the air conditioning high-voltage contactor of the pure electric bus is the set flag value, and the low-voltage of the main controller of the pure electric bus is greater than the third set voltage. If the conditions are met, then the overall condition of the pure electric bus and the battery condition are determined to be suitable for pre-charging the battery.

8. The control device for a pure electric bus according to claim 6, characterized in that, The second stage status parameters include: the bus voltage of the main controller of the pure electric bus, the bus voltage of the compressor in the air conditioning system of the pure electric bus, and the communication connection establishment status between the main controller and the driver of the pure electric bus. When the battery is being pre-charged, the control unit, after controlling the auxiliary relay to turn on for a first set time, determines whether the pre-charging of the battery has been completed based on the second stage state parameters, including: Determine whether the following conditions are met: the bus voltage of the main controller of the pure electric bus drops, or the bus voltage of the compressor in the air conditioner of the pure electric bus is less than the fourth set voltage and the bus voltage of the main controller of the pure electric bus is less than the fifth set voltage, or the communication connection between the main controller of the pure electric bus and the driver is not established. If the condition is not met, it is determined that the pre-charging of the battery has been completed; if the condition is met, it is determined that the pre-charging of the battery has not been completed.

9. The control device for a pure electric bus according to claim 8, characterized in that, The control unit, while pre-charging the battery, controls the auxiliary relay to be turned on for a first set time, and then determines whether the pre-charging of the battery has been completed based on the second stage state parameters, further including: If it is determined that the pre-charging of the battery has not been completed, the battery is pre-charged again after a third set time delay; and the number of times the pre-charging of the battery has not been completed is accumulated to obtain the number of pre-charging failures. If the number of pre-charge failures reaches a set number, a charging fault reminder message for the battery is initiated, and the charging control of the battery is terminated.

10. The control device for a pure electric bus according to any one of claims 6 to 9, characterized in that, The third-stage state parameters include: the bus voltage of the driver of the pure electric bus, the command sent by the driver of the compressor in the air conditioner of the pure electric bus to release the main relay, the bus voltage of the main controller of the pure electric bus, and the low voltage of the main controller of the pure electric bus. The control unit, when charging the battery, determines whether the charging of the battery has been completed based on the third-stage state parameters, including: Determine whether the following conditions are met: the bus voltage of the driver of the pure electric bus is less than the fifth set voltage, or the bus voltage of the driver of the pure electric bus is under-voltage protection, or a command to release the main relay is received from the driver of the compressor in the air conditioner of the pure electric bus, or the bus voltage of the main controller of the pure electric bus is less than the sixth set voltage, or the low voltage of the main controller of the pure electric bus is the seventh set voltage; If the condition is met, the battery charging is determined to be complete; if the condition is not met, the battery charging is determined to be incomplete.

11. A pure electric bus, characterized in that, include: The control device for a pure electric bus as described in any one of claims 6 to 10.

12. A storage medium, characterized in that, The storage medium includes a stored program, wherein, when the program is executed, the device containing the storage medium is controlled to perform the control method for the pure electric bus as described in any one of claims 1 to 5.

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