Charging mode for new energy sanitation vehicle

Abstract

The invention relates to the technical field of sanitation vehicle charging, in particular to a charging mode for a new energy sanitation vehicle, which comprises the steps that a VCU monitors a gun insertion signal in real time, when the VCU detects the gun insertion signal, an enable signal of a rear-end load of the sanitation vehicle is turned off, and after the rear-end load is turned off, a BMS external activation control relay is turned on; whether the sanitation vehicle enters an ON gear or not is judged, if yes, it is judged that the sanitation vehicle enters a charging starting process, and if not, it is judged that the sanitation vehicle enters an activation process; when the judgment result is that the sanitation vehicle enters the activation process, the VCU controls and closes a battery external activation control relay and awakens the BMS, the BMS starts pre-charging at the moment, and after pre-charging is completed, it is judged that the sanitation vehicle enters the charging starting process at the moment; and when the judgment result is that the sanitation vehicle enters the charging starting process, judging whether the key signal is disconnected or not, if yes, stopping outputting by a charger on the sanitation vehicle and stopping charging the battery pack, and otherwise, continuing charging.

Description

Technical Field

[0001] The present invention relates to the technical field of sanitation vehicle charging, and in particular to a charging method for a new energy sanitation vehicle. Background Art

[0002] With the booming global new energy industry, the sanitation vehicle sector is accelerating its transition to electrification. Sanitation vehicles powered by new energy batteries, with their zero emissions and low noise levels, are becoming the primary force in urban cleaning operations. Throughout the lifecycle of new energy sanitation vehicles, charging, as a core energy replenishment process, directly impacts their operational efficiency, operating costs, and safety.

[0003] Currently, new energy sanitation vehicle charging systems primarily use conventional AC charging, which features low equipment cost and convenient access, making it suitable for centralized nighttime charging of sanitation vehicles. However, existing technologies still have many limitations: First, most models use the ON charging mode. During the pre-charging stage, external voltage fluctuations can easily interfere with the charging process, causing pre-charging failure or equipment damage. Secondly, when the key signal is disconnected during charging (for example, if the user accidentally pulls out the key), the traditional system cannot respond in time and stop charging, posing safety risks such as overcharging and circuit short circuit. Based on this, there is an urgent need for a charging method for new energy sanitation vehicles that can solve the problems of unstable pre-charging and inability to stop charging in time after the key signal is disconnected in the existing technology, thereby improving the stability and safety of the charging process. Summary of the Invention

[0004] One of the purposes of the present invention is to provide a charging method for new energy sanitation vehicles, which can solve the problems in the prior art of unstable pre-charging and the inability to stop charging in time after the key signal is disconnected, thereby improving the stability and safety of the charging process.

[0005] In order to achieve the above object, a charging method for a new energy sanitation vehicle is provided, comprising the following steps: S1, VCU monitors the gun plug signal in real time. When the VCU detects the gun plug signal, it turns off the enable signal of the rear-end load of the sanitation vehicle, and after disconnecting the rear-end load, closes the BMS external activation control relay; S2. Determine whether the sanitation vehicle has entered the ON gear. If so, the sanitation vehicle is determined to have entered the charging process. Otherwise, the sanitation vehicle is determined to have entered the activation process. S3. When the result of the judgment is that the sanitation vehicle enters the activation process, the VCU controls the closing of the battery external activation control relay and wakes up the BMS. At this time, the BMS starts pre-charging. After the pre-charging is completed, it is judged that the sanitation vehicle enters the charging process; S4. When the result of the judgment is that the sanitation vehicle enters the charging process, it is judged whether the key signal is disconnected. If so, the charger on the sanitation vehicle stops outputting and stops charging the battery pack. Otherwise, charging continues until the battery pack is fully charged.

[0006] Technical Principles and Results of This Solution: This charging method achieves safe and orderly management of the charging process through the coordinated control of the vehicle control unit (VCU) and the battery management system (BMS). The core logic is as follows: The VCU monitors the charging signal in real time. Upon detecting a connection, it first disables the enable signals for the vehicle's rear-end loads (such as air conditioning, lights, and other non-essential equipment) to avoid power interference during charging. After disconnecting the rear-end loads, it closes the BMS external activation control relay to prepare the circuit for BMS activation.

[0007] By detecting whether the sanitation vehicle is in the ON position (key switch status), two scenarios are distinguished: In the ON position scenario, the charging process is directly determined to start, which is suitable for charging needs when the sanitation vehicle is in standby or low-power state. In the non-ON position scenario, the activation process is determined to start, which requires waking up the BMS and completing pre-charging before switching to the charging process. This is suitable for charging when the sanitation vehicle is completely powered off (OFF position).

[0008] During the activation process, the VCU controls the closing of the battery's external activation control relay, waking up the BMS. The BMS initiates the pre-charge process (charging the capacitor through the pre-charge resistor to avoid high current surges). After pre-charge is complete, it automatically switches to the charging process to ensure smooth power supply to the circuit.

[0009] During the charging process, the key signal is continuously monitored: if the key signal is disconnected (for example, the user removes the key), the charger immediately stops output to avoid unexpected charging status; if the key signal remains connected, charging continues to ensure process continuity.

[0010] In this solution, the pre-charge process is independently controlled by the BMS, which gradually establishes a stable voltage through the pre-charge resistor. The timing coordination between the VCU and the BMS (activating the relay first, then waking up the BMS) prevents external voltage fluctuations from directly impacting the main circuit. This effectively solves the problem of charging failure caused by external voltage jumps during the pre-charge process.

[0011] During the charging process, the key signal is monitored in real time. Once the key is disconnected, the VCU immediately cuts off the charger output and forces charging to stop. This avoids the problem of not being able to stop charging when the key is disconnected during charging in the ON position.

[0012] Upon detecting the key insertion signal, the VCU directly closes the battery's external activation relay, proactively waking up the BMS (traditional solutions require external power for activation). Charging can be initiated from a completely powered-off state, without requiring the vehicle to be in the "ON" position. This simplifies the charging process (without requiring a power-on initial connection) and reduces standby power consumption, making it particularly suitable for the convenience demands of frequent charging and operational scenarios, such as sanitation vehicles. This solves the existing issues of unstable pre-charging and the inability to terminate charging immediately after the key signal is disconnected, thereby improving the stability and safety of the charging process.

[0013] Furthermore, in the S3 , the BMS sends a request voltage and a request current of zero during the pre-charging process, and after the prediction is completed, sends a preset table-lookup value for the request voltage and the request current.

[0014] Beneficial Effects: During the initial pre-charge phase, the BMS requests zero current, acting as a buffer valve for the circuit. The charger prevents high current output until the circuit stabilizes. The pre-charge resistors gradually charge the busbar capacitors, increasing the current slowly. This prevents instantaneous high current shocks to the battery pack, charger, and wiring harness, significantly extending hardware life, reducing the risk of equipment failures due to current surges, and reducing maintenance costs and downtime, ensuring the long-term stable operation of the new energy sanitation vehicle charging system.

[0015] During pre-charge, the BMS sends a zero request voltage, clearly signaling to the charger that it's not charging. This prevents the charger from erroneously entering the constant-current charging phase prematurely due to detecting unstable voltage and current signals. After pre-charge is complete, the BMS sends preset lookup values ​​pre-calculated based on the battery's real-time status (parameters such as SOC and temperature). This allows the charger to accurately adjust output based on the battery's actual needs, ensuring accurate charging protocol execution and avoiding issues such as charging interruptions, overcharging, or undercharging caused by protocol misjudgment. This ensures charging safety and battery performance.

[0016] Furthermore, it also includes S5: when the battery pack is fully charged, the BMS sends a request voltage and a request current of zero, and disconnects the charging MOS.

[0017] Beneficial Effect: When the battery pack is fully charged, the BMS immediately sends a signal requesting zero voltage and current, explicitly instructing the charger to stop supplying power. Simultaneously, it disconnects the charging MOS (metal oxide semiconductor field-effect transistor), effectively severing the charging circuit at the hardware level. This dual-security mechanism of "software signal control + hardware circuit disconnection" completely eliminates overcharging caused by charger misjudgment or signal delays, effectively avoiding safety hazards such as battery bulging and fire caused by overcharging, and providing a solid defense for battery safety in new energy sanitation vehicles.

[0018] By precisely controlling the on and off of the charging MOS through the BMS, the charging system is ensured to quickly enter a safe standby state after the battery is fully charged. This avoids circuit failures (such as MOS overheating and line aging) that may be caused by the continuous conduction of the charging circuit. This enhances the stability and reliability of the entire charging system, reduces the downtime of sanitation vehicles caused by charging system failures, and ensures the continuity of new energy sanitation vehicle operations.

[0019] Furthermore, in S4 , when the key signal is disconnected, the requested voltage and requested current sent by the BMS are both zero. After a preset delay time, the BMS disconnects the charging MOS and enters sleep mode.

[0020] Beneficial Effect: When the key signal is disconnected, the BMS immediately sends a signal requesting zero voltage and current, rapidly shutting off the charger's power output and terminating charging at the software level. Simultaneously, after a preset delay, the charging MOS is disconnected, completely severing the circuit at the hardware level. This creates a dual-security mechanism of "software signal control and hardware-delayed power-off." This design effectively handles emergencies, such as user-inadvertent key removal and sudden vehicle malfunctions, ensuring safe termination of the charging process and preventing potential safety hazards such as current surges and sparks caused by sudden power outages. This provides an additional safeguard for charging new energy sanitation vehicles.

[0021] The preset delay time allows for a buffer before disconnection, preventing the back EMF generated by a momentary power outage from impacting the battery pack, charger, and circuit components. By first stopping power output and then gradually disconnecting the charging MOSFET, the system reduces equipment losses caused by sudden current surges, effectively extending the service life of key components such as the battery, charger, and MOSFET, reducing equipment failure rates and maintenance costs, and improving the overall durability of the new energy sanitation vehicle charging system. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a flow chart of a charging method for a new energy sanitation vehicle in Example 1 of the present invention. DETAILED DESCRIPTION

[0023] The following is further described in detail through specific implementation methods: Example 1 A charging method for new energy sanitation vehicles, basically as follows Figure 1 As shown, the following steps are included: S1, VCU monitors the gun plug signal in real time. When the VCU detects the gun plug signal, it turns off the enable signal of the rear-end load of the sanitation vehicle, and after disconnecting the rear-end load, closes the BMS external activation control relay; S2. Determine whether the sanitation vehicle has entered the ON gear. If so, the sanitation vehicle is determined to have entered the charging process. Otherwise, the sanitation vehicle is determined to have entered the activation process. S3. When the judgment result is that the sanitation vehicle enters the activation process, the VCU controls the closing of the battery external activation control relay and wakes up the BMS. At this time, the BMS starts pre-charging. After the pre-charging is completed, it is judged that the sanitation vehicle enters the charging process. In S3, the BMS sends the requested voltage and requested current as zero during the pre-charging process. After the prediction is completed, the requested voltage and requested current send the preset table lookup values.

[0024] S4: When the sanitation vehicle enters the charging process, it is determined whether the key signal is disconnected. If so, the charger on the sanitation vehicle stops outputting and stops charging the battery pack. Otherwise, charging continues until the battery pack is fully charged. In S4, if the key signal is disconnected, the BMS sends a request voltage and a request current of zero. After a preset delay, the BMS disconnects the charging MOS and enters sleep mode. In this embodiment, the BMS message transmission logic is modified. When the key is turned, the VCU controls the closing of the BMS external activation relay, activating the BMS to start the pre-charge process. During the pre-charge period, the request voltage and request current are sent as 0. After the pre-charge is completed, the table value is sent to prevent the charger from operating prematurely.

[0025] It also includes S5, when the battery pack is fully charged, the BMS sends a request voltage and a request current of zero, and disconnects the charging MOS. In this embodiment, the BMS external activation signal is associated with the gun plug signal. When the vehicle is in the ON gear, the BMS sends a request voltage and current that are both lookup values. After the gun is plugged in, charging can proceed normally. When the vehicle is in the OFF gear, after the gun is plugged in, the VCU detects the gun plug signal, determines that the BMS state is not working, closes the BMS external activation switch control relay, and the BMS starts pre-charging. During the pre-charging process, the request voltage and current sent are both 0, and the charger cannot start, which interferes with the pre-charging voltage. After the pre-charging is completed, the charging MOS is closed and the lookup value is sent. At this time, the charger starts outputting and charging proceeds normally. If charging is in the ON gear, the key signal is disconnected during charging, the VCU disconnects the BMS external activation switch control relay, and the BMS sends a request voltage and current that are 0, preventing the charger from continuing to output. The charging MOS is disconnected after a delay of 10S, and charging ends.

[0026] The above is only an embodiment of the present invention. Common knowledge such as the known specific structures and characteristics in the scheme is excessively described here. Ordinary technicians in the relevant field are aware of all common technical knowledge in the technical field of the invention before the application date or priority date, can obtain all existing technologies in the field, and have the ability to apply conventional experimental means before that date. Ordinary technicians in the relevant field can improve and implement this scheme in combination with their own abilities under the enlightenment given by this application. Some typical known structures or known methods should not become obstacles for ordinary technicians in the relevant field to implement this application. It should be pointed out that for those skilled in the art, without departing from the structure of the present invention, several variations and improvements can be made, which should also be regarded as the scope of protection of the present invention. These will not affect the effect of the implementation of the present invention and the practicality of the patent. The scope of protection required by this application shall be based on the content of its claims, and the specific implementation methods and other records in the specification can be used to interpret the content of the claims.

Claims

1. A charging method for a new energy sanitation vehicle, characterized by: The following steps are involved: S1, VCU monitors the gun plug signal in real time. When the VCU detects the gun plug signal, it turns off the enable signal of the rear-end load of the sanitation vehicle, and after disconnecting the rear-end load, closes the BMS external activation control relay; S2. Determine whether the sanitation vehicle has entered the ON gear. If so, the sanitation vehicle is determined to have entered the charging process. Otherwise, the sanitation vehicle is determined to have entered the activation process. S3. When the result of the judgment is that the sanitation vehicle enters the activation process, the VCU controls the closing of the battery external activation control relay and wakes up the BMS. At this time, the BMS starts pre-charging. After the pre-charging is completed, it is judged that the sanitation vehicle enters the charging process; S4. When the result of the judgment is that the sanitation vehicle enters the charging process, it is judged whether the key signal is disconnected. If so, the charger on the sanitation vehicle stops outputting and stops charging the battery pack. Otherwise, charging continues until the battery pack is fully charged.

2. A charging method for a new energy sanitation vehicle according to claim 1, characterized in that: In S3 , the BMS sends a request voltage and a request current of zero during the pre-charging process. After the prediction is completed, the request voltage and the request current send preset table values.

3. A charging method for a new energy sanitation vehicle according to claim 2, characterized in that: It also includes S5. When the battery pack is fully charged, the BMS sends a request voltage and a request current of zero and disconnects the charging MOS.

4. A charging method for a new energy sanitation vehicle according to claim 3, characterized in that: When the result of the judgment in S4 is that the key signal is disconnected, the requested voltage and requested current sent by the BMS are both zero. After a preset delay time, the BMS disconnects the charging MOS and enters sleep mode.

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