Power-on control method for high-voltage lithium battery forklift

Abstract

A power-on control method for a high-voltage lithium battery forklift comprises the steps that power-on logic is triggered through gear change of a key switch or a charging signal of a charging interface; when the key switch is closed and located at a starting gear, a first power relay is powered on, so that a storage battery supplies power to a high-voltage lithium battery management system and a vehicle control unit; a key switch signal is loaded to a high-voltage lithium battery management system and a vehicle control unit; the high-voltage lithium battery management system controls on-off of a circuit between the high-voltage lithium battery and the direct-current power source conversion module through the second power source relay, and the whole vehicle controller controls opening and closing of the output end of the direct-current power source conversion module through the second power source relay. According to the power-on control method for the high-voltage lithium battery forklift, the problem of power shortage is solved, and standby power consumption is effectively reduced.

Description

Technical Field

[0001] This invention relates to a power-on control method, and more particularly to a power-on control method applied to a high-voltage lithium-ion forklift, belonging to the field of forklift control technology. Background Technology

[0002] Currently, with the maturity and widespread adoption of high-voltage lithium battery technology, electric forklifts are gradually evolving from low-voltage systems to high-voltage systems. For high-voltage lithium battery systems, each forklift manufacturer has its own power-on control logic to coordinate the high-voltage lithium battery and the additional auxiliary power supply (24V battery).

[0003] There are three conventional methods to achieve high and low voltage power supply for high-voltage lithium-ion forklifts: Option 1: Add a main power switch at the back end of the auxiliary power supply. Turn on the main power switch to power on the high-voltage lithium battery management system (BMS) and the vehicle controller (VCU). Then, wake up the high-voltage lithium battery management system (BMS) and the vehicle controller (VCU) through a key signal or a charging gun signal. Then, use program control to achieve high and low voltage power-on.

[0004] Option 2: The auxiliary power supply does not have a main power switch at the back end. It provides continuous power to the high-voltage lithium battery management system (BMS). The power supply and wake-up of the vehicle controller (VCU) are controlled by the key signal or the charging gun signal. Then, the program controls the high and low voltage power-on.

[0005] Option 3: The high-voltage lithium battery management system (BMS) and the vehicle control unit (VCU) are constantly powered, and the vehicle does not lose power when the voltage is low. The voltage of the auxiliary power supply is monitored in real time. When a low voltage is detected, the DC power conversion module is activated to charge the auxiliary power supply through the high voltage of the high-voltage lithium battery.

[0006] The above technical solutions have the following problems: Solution 1 requires turning off the main power switch after each operation. If the driver fails to do so properly, the auxiliary power supply may run out of power, preventing the vehicle from starting. Solution 2 keeps the high-voltage lithium battery management system (BMS) in standby mode for extended periods. During long-distance transport, the standby power consumption of the BMS may also cause the auxiliary power supply to run out of power. Solution 3 keeps the low-voltage battery powered on for extended periods, increasing additional power consumption. Therefore, there is an urgent need for a power-on control method for high-voltage lithium-ion forklifts that can solve the above problems. Summary of the Invention

[0007] The purpose of this invention is to overcome the above-mentioned shortcomings and provide a power-on control method for high-voltage lithium-ion forklifts, which solves the problem of power depletion and effectively reduces standby power consumption.

[0008] The objective of this invention is achieved as follows: A power-on control method for a high-voltage lithium-ion forklift, which triggers the power-on logic through a change in the key switch position or a charging signal from the charging port: When the key switch is closed in the start position, power relay one is energized, enabling the battery to supply power to the high-voltage lithium battery management system and the vehicle controller, while simultaneously loading the key switch signal to the high-voltage lithium battery management system and the vehicle controller; the high-voltage lithium battery management system controls the circuit connection and disconnection between the high-voltage lithium battery and the DC power conversion module through power relay two, and the vehicle controller controls the opening and closing of the output terminal of the DC power conversion module through power relay two. When the charging port is plugged into the charging gun, the charging signal of the charging port causes the control terminal of the power relay one to be energized and closed through the diode. The closure of the power relay one enables the battery to supply power to the high-voltage lithium battery management system and the vehicle controller, while simultaneously loading the charging signal to the high-voltage lithium battery management system and the vehicle controller.

[0009] Preferredly, the high-voltage lithium-ion forklift power-on control method is based on a high-voltage lithium-ion forklift power-on control circuit, including a power relay one, a power relay two, and a high-voltage relay. The key switch is a single-pole double-throw switch. One switch of the key switch is connected in series with the control terminal of power relay one and then connected between the positive and negative terminals of the battery. One controlled terminal of power relay one is connected to the positive terminal of the battery, and the other terminal is connected to the power output terminal of the control system, the power input terminal of the vehicle controller, the power input terminal of the high-voltage lithium-ion battery management system, the output terminal of the DC power conversion module, one controlled terminal of power relay two, and one terminal of the other switch. The other controlled terminal of power relay two is connected to the power output terminal of the equipment. The other terminal of the key switch is connected to the power-on signal control terminal of the high-voltage lithium-ion battery management system and the power-on signal control terminal of the vehicle controller. The control terminal of power relay two is connected to the control terminal of the vehicle controller. The high-voltage lithium-ion battery and the controlled terminal of the high-voltage relay are connected in series to the power input terminal of the DC power conversion module, and the control terminal of the high-voltage relay is connected to the output terminal of the high-voltage lithium-ion battery management system.

[0010] Prior to this, when the key switch is closed, both switches in the key switch are closed. The first switch connects the control terminal of the power relay one to the battery, which in turn connects the controlled terminal of the power relay one. At this time, the battery supplies power to the high-voltage lithium battery management system, the vehicle controller, and the power output terminal of the control system. At the same time, the key switch can also load the key switch signal to the power-on signal control terminal of the high-voltage lithium battery management system and the vehicle controller through the closed controlled terminal of the power relay one to trigger them.

[0011] Prior to this, after receiving the key switch signal, the high-voltage lithium battery management system, upon determining that the high-voltage lithium battery is not faulty, controls the high-voltage relay to engage, connecting the high-voltage lithium battery to the DC power conversion module. Once the DC power conversion module receives high voltage, it enters standby mode. Simultaneously, the DC power conversion module communicates with the vehicle controller. The vehicle controller sends a work message to the DC power conversion module. Upon receiving the work instruction message, the DC power conversion module begins to operate, causing its DC output terminal to start outputting power.

[0012] Prior to this, after the DC power conversion module starts outputting power, it feeds back its working status to the vehicle controller. After receiving the feedback that the DC power conversion module is working, the vehicle controller controls the second power relay to engage, so that the high voltage of the high-voltage lithium battery is regulated by the DC power conversion module and then connected to the power output terminal of the device via the second power relay.

[0013] Priority is given to connecting the charging signal of the charging interface to one end of the control terminal of the power relay one via a diode. The other end of the control terminal of the power relay one is grounded. The charging signal of the charging interface is connected to the signal input terminals of the high-voltage lithium battery management system and the vehicle controller.

[0014] Compared with the prior art, the beneficial effects of the present invention are: First, it solves the problem of needing to manually turn off the power in conventional solution one, eliminating the need for a main power switch and thus eliminating the need to manually switch the auxiliary power supply. Second, it uses a key-controlled electromagnetic switch to connect and disconnect the auxiliary power supply, thus solving the problems of power depletion and increased power consumption caused by constant power supply in solutions two and three. Third, when the vehicle is not in use or charging, the vehicle power supply can be completely disconnected, reducing vehicle standby power consumption and the risk of auxiliary power depletion, thereby avoiding power depletion. Attached Figure Description

[0015] Figure 1 This is a circuit diagram of a circuit used in the power-on control method for a high-voltage lithium-ion forklift according to the present invention.

[0016] in: Battery AUXP, high-voltage lithium battery BATT, DC power conversion module DC, power relay MK1, power relay MK2, high-voltage relay HK1, key switch KS, power fuse FU1, power fuse FU2, power fuse FU3, high-voltage lithium battery management system BMS, vehicle controller VCU, fast charging diode D1, slow charging diode D2. Detailed Implementation

[0017] See Figure 1This invention relates to a power-on control method for a high-voltage lithium-ion forklift, which triggers the power-on logic through a change in the position of the key switch KS or a charging signal from the charging interface. When the key switch KS is closed in the start position, power relay MK1 is energized, enabling the battery AUXP to supply power to the high-voltage lithium battery management system (BMS), vehicle controller (VCU), and control system. At the same time, it loads the power-on logic level (i.e., the key switch signal) to the high-voltage lithium battery management system (BMS) and vehicle controller (VCU). The high-voltage lithium battery management system (BMS) controls the circuit connection between the high-voltage lithium battery BATT and the DC power conversion module (DC) through power relay MK2. The vehicle controller (VCU) controls the connection of the DC output terminal of the DC power conversion module (DC) through power relay MK2.

[0018] During charging, the charging signal from the charging interface powers the control terminal of the power relay MK1 via a diode, thereby closing the power relay MK1. This allows the battery AUXP to supply power to the high-voltage lithium battery management system (BMS), vehicle controller (VCU), and control system, while simultaneously loading the charging signal from the charging interface onto the high-voltage lithium battery management system (BMS) and vehicle controller (VCU).

[0019] See Figure 1 The diagram shown is a circuit diagram for implementing the power-on control method of the high-voltage lithium battery forklift of this invention. This patent mainly adds power relay MK1, power relay MK2 and high-voltage relay HK1 to form a completely new control circuit based on the original forklift control system, which consists of battery AUXP, high-voltage lithium battery BATT, DC power conversion module DC, key switch KS, high-voltage lithium battery management system BMS and vehicle controller VCU. The AUXP battery provides 24V auxiliary power to the system. Key switch KS, the system control switch, controls the power on and off of the entire vehicle; The DC power conversion module converts high voltage to 24V voltage, and the vehicle controller (VCU) is the vehicle controller. The high-voltage lithium battery BATT is converted into a 24V output voltage through a DC power conversion module. Power relay MK1 controls the 24V auxiliary power supply. Power relay MK2 controls the power supply to lights, instruments, and peripherals. The high-voltage relay HK1 controls the high-voltage power supply to the high-voltage lithium battery BATT; Fast charging diode D1 and slow charging diode D2 serve to isolate slow charging signals and fast charging signals; Specifically, the implementation circuit is as follows: The key switch KS is a single-pole double-throw switch. One switch of key switch KS is connected in series with the control terminal of power relay MK1 and then connected between the positive and negative terminals of the battery AUXP (and a power fuse FU1 is connected in series between the control terminal of power relay MK1 and the positive terminal of battery AUXP). One end of the controlled terminal of power relay MK1 is connected to the positive terminal of battery AUXP, and the other end is connected to the power output terminal of the control system, the power input terminal of the vehicle control unit (VCU), the power input terminal of the high-voltage lithium battery management system (BMS), the output terminal of the DC power conversion module (DC), and power relay MK2. One end of the controlled terminal and one end of the other circuit of the key switch KS are connected to the power output terminal of the equipment. The other end of the other circuit of the key switch KS is connected to the power-on signal control terminal of the high-voltage lithium battery management system BMS and the power-on signal control terminal of the vehicle controller VCU. The control terminal of the power relay MK2 is connected to the control terminal (V2) of the vehicle controller VCU. At the same time, power fuse FU3 and power fuse FU2 are connected in series on the power input terminal of the vehicle controller VCU and the power input terminal of the high-voltage lithium battery management system BMS, respectively. When the key switch KS is closed, both switches in the key switch KS are closed. The first switch enables the control terminal of the power relay MK1 to conduct and receive power from the battery AUXP, thereby turning on the controlled terminal of the power relay MK1. At this time, the battery AUXP supplies power to the high-voltage lithium battery management system BMS, the vehicle controller VCU, and the power output terminal of the control system. At the same time, the key switch KS can also apply the power-on logic level to the power-on signal control terminals of the high-voltage lithium battery management system BMS and the vehicle controller VCU through the closed controlled terminal of the power relay MK1 to trigger them.

[0020] Meanwhile, the controlled terminals of the high-voltage lithium battery BATT and the high-voltage relay HK1 are connected in series to the power input terminal of the DC power conversion module DC, and the control terminal of the high-voltage relay HK1 is connected to the output terminals (B8 and B9) of the high-voltage lithium battery management system BMS.

[0021] Reference Figure 1 The vehicle power-on process after discharge: When the driver turns on the ignition switch KS, line 1.01 in the diagram is energized, power relay MK1 is activated, and line +30 in the diagram is energized, thus powering up the high-voltage lithium battery management system (BMS) and the vehicle control unit (VCU) simultaneously, and they begin to work. Simultaneously, the activated power relay MK1 energizes the ignition switch signal line 2.01, providing the ignition switch signal to both the BMS and VCU. After receiving the ignition switch signal and determining that the lithium battery is not faulty, the BMS outputs B8 and B9, controlling the high-voltage relay HK1 to activate. The high-voltage lithium battery BATT connects to the DC power conversion module DC. After receiving high-voltage power, the DC power conversion module DC enters standby mode and completes CAN communication with the VCU. Then, the VCU sends a work message to the DC power conversion module DC via the CAN bus. Upon receiving the work command message, the DC power conversion module DC begins to work, and its output terminal begins to output 24V power, thus powering up the vehicle control system. The DC power conversion module (DC) simultaneously feeds back its working status to the vehicle controller (VCU) via the CAN line. After receiving the feedback that the DC power conversion module (DC) is working, the VCU outputs a high level on its control terminal V2 line to activate the power relay MK2. This allows the high voltage of the high-voltage lithium battery BATT to be regulated to 24V by the DC power conversion module (DC) and then connected to the power output terminal of the equipment via the power relay MK2, thus providing power to the lights, instruments, and peripherals, thereby completing the entire power-on process. The circuit for implementing charging and power-on management is as follows: Charging is divided into slow charging and fast charging. The charging interfaces are different, but the circuit control and process are the same. Taking a fast charging interface as an example: When the driver plugs in the fast charging gun, the fast charging gun provides a fast charging signal A1, which energizes the power relay MK1 and makes it close, which is consistent with the closing of the vehicle power key switch KS. At this time, the +30 line in the figure is powered on, and the control system power is powered on, so the high-voltage lithium battery management system BMS and the vehicle controller VCU are powered on at the same time and start working. Meanwhile, the fast charging signal from the fast charging gun is input to the high-voltage lithium battery management system (BMS) and the vehicle controller (VCU). After receiving the fast charging signal, the BMS, after determining that the high-voltage lithium battery BATT is not faulty, outputs B8 and B9 to control the high-voltage relay HK1 to engage. The high-voltage lithium battery BATT is then connected to the DC power conversion module (DC). After the DC power conversion module receives high voltage power, it enters standby mode and completes CAN communication with the VCU. Then, the VCU sends a DC work message through the CAN bus. After receiving the work command message, the DC starts working and outputs 24V power, and the vehicle controller system is powered on.

[0022] If the key switch KS is not turned on at this time and there is no key signal, the vehicle controller VCU will not control the power relay MK2 to close. At this time, the lights, instruments and peripherals will not have power. If the key switch KS is open or closed at this time, the vehicle controller VCU receives the key signal and controls the power relay MK2 to close, at which point the lights, instruments and peripherals are powered.

[0023] Complete, when the forklift finishes working or charging and is powered off: The entire vehicle power-off process during discharge: When the driver turns off the key switch KS, line 1.01 in the diagram is de-energized, and power relay MK1 disconnects. At this time, the DC power conversion module DC is still working, and line +30 in the diagram is still energized. However, the vehicle control unit (VCU) immediately detects that the key switch signal is disconnected (i.e., no high-level signal is applied) and sends a shutdown message to the DC power conversion module DC via the CAN bus. After receiving the shutdown message, the DC power conversion module DC stops working and disconnects the 24V power output, thus completing the vehicle power-off process.

[0024] The process of the vehicle being powered off during charging: Similarly, when fully charged or charging stops during the process, charging signal A1 or A2 is disconnected, line 1.01 in the diagram is de-energized, and power relay MK1 is de-energized and disconnected. Likewise, at this time, the DC power conversion module DC is still working, and line +30 in the diagram is still energized. After the vehicle controller (VCU) detects that the charging signal is disconnected, it sends a shutdown message to the DC power conversion module (DC) via the CAN bus. Upon receiving the shutdown message, the DC power conversion module (DC) stops working, disconnects the 24V power output, and completes the vehicle power-off process.

[0025] Additionally, it should be noted that the above-described specific implementation is merely an optimized solution of this patent, and any modifications or improvements made by those skilled in the art based on the above concept are within the scope of protection of this patent.

Claims

1. A power-on control method for a high-voltage lithium-ion forklift, characterized in that: The power-on logic is triggered by changes in the key switch position or by a charging signal from the charging port: When the key switch is closed in the start position, power relay one is energized, enabling the battery to supply power to the high-voltage lithium battery management system and the vehicle controller, while simultaneously loading the key switch signal to the high-voltage lithium battery management system and the vehicle controller; the high-voltage lithium battery management system controls the circuit connection and disconnection between the high-voltage lithium battery and the DC power conversion module through power relay two, and the vehicle controller controls the opening and closing of the output terminal of the DC power conversion module through power relay two. When the charging port is plugged into the charging gun, the charging signal of the charging port causes the control terminal of the power relay one to be energized and closed through the diode. The closure of the power relay one enables the battery to supply power to the high-voltage lithium battery management system and the vehicle controller, while simultaneously loading the charging signal to the high-voltage lithium battery management system and the vehicle controller.

2. The power-on control method for a high-voltage lithium-ion forklift according to claim 1, characterized in that: The power-on control method for the high-voltage lithium-ion forklift is based on a power-on control circuit for the high-voltage lithium-ion forklift, including a power relay 1, a power relay 2, and a high-voltage relay. The key switch is a single-pole double-throw switch. One switch of the key switch is connected in series with the control terminal of power relay 1 and then connected between the positive and negative terminals of the battery. One controlled terminal of power relay 1 is connected to the positive terminal of the battery, and the other terminal is connected to the power output terminal of the control system, the power input terminal of the vehicle controller, the power input terminal of the high-voltage lithium-ion battery management system, the output terminal of the DC power conversion module, one controlled terminal of power relay 2, and one terminal of the other switch. The other controlled terminal of power relay 2 is connected to the power output terminal of the equipment. The other terminal of the key switch is connected to the power-on signal control terminal of the high-voltage lithium-ion battery management system and the power-on signal control terminal of the vehicle controller. The control terminal of power relay 2 is connected to the control terminal of the vehicle controller. The high-voltage lithium-ion battery and the controlled terminal of the high-voltage relay are connected in series to the power input terminal of the DC power conversion module, and the control terminal of the high-voltage relay is connected to the output terminal of the high-voltage lithium-ion battery management system.

3. The power-on control method for a high-voltage lithium-ion forklift according to claim 2, characterized in that: When the key switch is closed, both switches in the key switch are closed. The first switch connects the control terminal of the power relay to the battery, which in turn connects the controlled terminal of the power relay. At this time, the battery supplies power to the high-voltage lithium battery management system, the vehicle controller, and the power output terminal of the control system. At the same time, the key switch can also load the key switch signal to the power-on signal control terminal of the high-voltage lithium battery management system and the vehicle controller through the closed controlled terminal of the power relay to trigger them.

4. The power-on control method for a high-voltage lithium-ion forklift according to claim 3, characterized in that: After receiving the key switch signal, the high-voltage lithium battery management system determines that the high-voltage lithium battery is not faulty. It then controls the high-voltage relay to engage, connecting the high-voltage lithium battery to the DC-DC power conversion module. Once the DC-DC power conversion module receives high voltage, it enters standby mode. Simultaneously, the DC-DC power conversion module communicates with the vehicle controller. The vehicle controller sends a work message to the DC-DC power conversion module. Upon receiving the work instruction message, the DC-DC power conversion module begins to output power.

5. The power-on control method for a high-voltage lithium-ion forklift according to claim 4, characterized in that: After the DC power conversion module starts outputting power, it feeds back its working status to the vehicle controller. After receiving the feedback that the DC power conversion module is working, the vehicle controller controls the second power relay to engage, so that the high voltage of the high-voltage lithium battery is regulated by the DC power conversion module and then connected to the power output terminal of the device via the second power relay.

6. The power-on control method for a high-voltage lithium-ion forklift according to claim 2, characterized in that: The charging signal of the charging interface is connected to one end of the control terminal of the power relay one through a diode. The other end of the control terminal of the power relay one is grounded. The charging signal of the charging interface is connected to the signal input terminal of the high-voltage lithium battery management system and the vehicle controller.

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