Charging and discharging control method and device and working machine

Abstract

The invention provides a charging and discharging control method and device and an operation machine, and belongs to the electrical technical field of operation machines. The method comprises the steps that under the condition that the operation machine is in a traveling state, the battery charge state of the operation machine is obtained; under the condition that the battery charge state is smaller than a first preset charge threshold value, the initial torque of the generator is adjusted according to the actual output current and the target output current of the operation machine generator, and the target torque corresponding to the generator is obtained; a torque adjusting instruction is sent to a generator; the torque adjusting instruction carries a target torque; the generator is controlled to operate to power a battery of the work machine based on the target torque in response to the torque adjustment command. According to the invention, the defects of low charging and discharging efficiency of the battery of the operation machine and influence on the service life of the battery caused by unnecessary charging and discharging under different working conditions in the existing battery charging and discharging control strategy of the operation machine are overcome.

Description

Technical Field

[0001] The present invention relates to the field of electrical technology of operating machinery, and in particular to a charge and discharge control method, a charge and discharge control device, an operating machinery, and a machine-readable storage medium. Background Art

[0002] Currently, operating machinery (such as ultra-large excavators) uses electricity generated by a generator to drive an electric motor, which in turn drives electrical appliances (such as air conditioners) while in motion. Excess generator energy is stored in batteries. When electrical appliances are needed while parked, the engine does not need to be started. Instead, the battery directly drives the electric motor through a motor driver, which in turn drives the electrical appliances. This eliminates the need to start the engine during lunch breaks, saving fuel.

[0003] However, the existing battery charge and discharge control strategy of the operating machinery causes unnecessary charging and discharging under different working conditions, resulting in low charging and discharging efficiency of the operating machinery's battery, which affects the battery's service life. Summary of the Invention

[0004] The purpose of the embodiments of the present invention is to provide a charging and discharging control method, device and operating machinery to solve the defect that the battery charging and discharging control strategy of the existing operating machinery causes unnecessary charging and discharging under different working conditions, resulting in low charging and discharging efficiency of the operating machinery's battery and affecting the battery's service life.

[0005] To achieve the above objectives, an embodiment of the present invention provides a charge and discharge control method, comprising: When the working machine is in a driving state, obtaining a battery state of charge of the working machine; When the battery state of charge is less than a first preset charge threshold, adjusting the initial torque of the generator according to the actual output current and the target output current of the generator of the working machine to obtain a target torque corresponding to the generator; sending a torque adjustment instruction to the generator; the torque adjustment instruction carries the target torque; The generator is controlled to operate to supply power to a battery of the work machine based on the target torque in response to the torque adjustment command.

[0006] Optionally, adjusting the initial torque of the generator according to the actual output current and the target output current of the working machine generator to obtain the target torque corresponding to the generator includes: determining a candidate torque corresponding to the generator based on a deviation value, a preset adjustable proportional variable, a preset adjustable integral variable, a preset first intermediate variable, and a preset second intermediate variable; the deviation value being a difference between the target output current and the actual output current; the deviation value, the adjustable proportional variable, the adjustable integral variable, and the second intermediate variable being positively correlated with the candidate torque, and the first intermediate variable being negatively correlated with the candidate torque; When the candidate torque is less than a preset threshold, updating the candidate torque, the first intermediate variable, and the second intermediate variable; Return step: Based on the deviation value, the preset adjustable proportional variable, the preset adjustable integral variable, the preset first intermediate variable and the preset second intermediate variable, determine the candidate torque corresponding to the generator, until the number of updates reaches the preset number, and determine the last updated candidate torque as the target torque.

[0007] Optionally, after obtaining the battery state of charge of the working machine, the method further includes: sending a zero torque command to the generator when the battery state of charge is greater than or equal to a second preset charge threshold; the second preset charge threshold is less than the first preset charge threshold; The generator is controlled to stop supplying power to the battery in response to the zero torque command, and the battery is controlled to supply power to the electric motor.

[0008] Optionally, the method further includes: When the working machine is in a parked state, the battery state of the working machine is greater than or equal to a third set charge threshold, and the battery temperature of the working machine is greater than or equal to a set temperature threshold, the battery is controlled to power the electric motor.

[0009] Optionally, when the working machine is in a driving state, before obtaining the battery state of charge of the working machine, the method further includes: When the operating machine is powered on, controlling the power distribution box circuit to pre-charge the battery; When the battery pre-charging is completed, the battery is controlled by the distribution box circuit to be connected to the main circuits of the generator and the motor respectively.

[0010] Optionally, the target output current is calculated based on the demand current of the motor and the demand current of the battery; the demand current of the motor is calculated based on the total demand power of electrical consumers, the set voltage of the motor and the set power factor of the motor; the total demand power of electrical consumers and the demand current of the motor are positively correlated; the set voltage of the motor and the set power factor of the motor are negatively correlated with the demand current of the motor, respectively; the demand current of the battery is calculated based on the first power, the set charging voltage of the battery and the set charging time of the battery; the first power and the demand current of the battery are positively correlated; the set charging voltage of the battery and the set charging time of the battery are negatively correlated with the demand current of the battery, respectively; the first power represents the power lost by the battery during the last parking period.

[0011] On the other hand, an embodiment of the present invention further provides a charge and discharge control device, comprising: an acquisition module, configured to acquire the state of charge of the battery of the operating machine when the operating machine is in a driving state; a calculation module, configured to adjust the initial torque of the generator according to the actual output current and the target output current of the generator of the working machine to obtain a target torque corresponding to the generator when the state of charge of the battery is less than a first preset charge threshold; a sending module, configured to send a torque adjustment instruction to the generator; the torque adjustment instruction carries the target torque; A control module is configured to control the generator to operate based on the target torque in response to the torque adjustment command to supply power to a battery of the work machine.

[0012] On the other hand, an embodiment of the present invention further provides an operating machine, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the above-mentioned charge and discharge control method when executing the program.

[0013] Optionally, the working machine further includes a generator driver and a battery electrically connected to the processor, a generator electrically connected to the generator driver, and an electric motor electrically connected to the battery; The generator driver is used to control the generator to operate based on the target torque; The generator is used to supply power to the battery when the operating machine is in a driving state; The battery is used to power the electric motor; The electric motor is used to supply power to electrical appliances of the operating machine.

[0014] On the other hand, the present invention also provides an electronic device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the above-mentioned charge and discharge control method when executing the program.

[0015] On the other hand, the present invention further provides a machine-readable storage medium having a computer program stored thereon, which implements the above-mentioned charge and discharge control method when executed by a processor.

[0016] Through the above technical solution, when the working machine is in motion, this embodiment of the present invention adjusts the initial torque of the generator based on the actual output current and target output current of the working machine's generator, based on the battery state of charge being less than a first preset charge threshold, to obtain a corresponding target torque for the generator. This control then controls the generator to operate based on the target torque to power the working machine's battery. This embodiment of the present invention accurately and rationally controls the charging and discharging of the working machine's battery based on information such as the working machine's operating conditions and the lithium battery's state of charge, thereby improving the lithium battery's charging and discharging efficiency and lifespan and optimizing overall energy management for the equipment.

[0017] Other features and advantages of the embodiments of the present invention will be described in detail in the subsequent detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The accompanying drawings are used to provide a further understanding of the embodiments of the present invention and constitute a part of the specification. Together with the following detailed description, they are used to explain the embodiments of the present invention, but do not constitute a limitation of the embodiments of the present invention. In the accompanying drawings: Figure 1 This is one of the flow charts of the charge and discharge control method provided by the present invention; Figure 2 This is one of the structural diagrams of the charge and discharge control device provided by the present invention; Figure 3 This is one of the structural diagrams of the operating machinery provided by the present invention; Figure 4 This is the second structural schematic diagram of the operating machinery provided by the present invention. DETAILED DESCRIPTION

[0019] The following describes the specific implementation of the embodiment of the present invention in detail with reference to the accompanying drawings. It should be understood that the specific implementation described herein is only used to illustrate and explain the embodiment of the present invention and is not used to limit the embodiment of the present invention.

[0020] Existing lithium-ion battery charge and discharge control strategies for operating machinery fail to accurately manage charge and discharge based on the battery's state of charge (SOC) and the vehicle's power requirements under different operating conditions, particularly when switching between driving and parking. This results in inefficient battery utilization. Existing technologies lack effective preventative and protective measures against the potential overcharging of lithium-ion batteries caused by reverse charging of the electric motor when the air conditioner is stopped, impacting battery safety and service life.

[0021] In view of this, an object of the embodiments of the present invention is to provide a charge and discharge control method, device, and operating machine to solve the problems of the lithium battery charge and discharge control strategy of the above-mentioned existing operating machines.

[0022] Please refer to Figure 1 , an embodiment of the present invention provides a charge and discharge control method, comprising: Step 101: When the operating machine is in a driving state, obtain the battery charge state of the operating machine.

[0023] In one embodiment, a working machine (e.g., an excavator) according to the present invention includes an engine, a processor (or controller), a display screen, a power distribution box circuit, a generator driver, a generator, a motor driver, a motor, a pulley, an air conditioner compressor, and a battery. The processor is electrically connected to the generator driver, the motor driver, and the display screen, respectively, providing overall control. The power distribution box circuit is electrically connected to the generator driver, the motor driver, and the battery, respectively. The power distribution box circuit controls the connection between the battery and the generator driver via main relay 1, and controls the connection between the battery and the motor driver via main relay 2. The power distribution box circuit also includes a pre-charge relay for controlling battery pre-charging. The generator driver is the generator's drive circuit, controlling the generator to operate according to a target torque meter to generate electrical energy. Furthermore, the generator driver is responsible for converting the alternating current (AC) output from the generator into direct current (DC). The motor driver is the motor's drive circuit, controlling the motor to generate mechanical energy from the battery's electrical energy, thereby driving the pulley to provide energy for the air conditioner compressor. Furthermore, the motor driver is responsible for converting the DC output from the battery into AC. The generator can be a water-cooled permanent magnet synchronous generator, and the motor can be a water-cooled permanent magnet synchronous motor. Batteries can be made of various materials available on the market, such as lithium batteries. The number of compressors for the air conditioner can be set according to actual conditions. For example, if three air conditioners are set, three compressors for the air conditioner are set.

[0024] When the working machine's engine is running, it is considered to be in driving mode. For example, if the engine speed is greater than 800 rpm, the engine is considered to be in driving mode. At this time, the working machine's processor obtains the working machine's battery state of charge (SOC), facilitating subsequent battery charge and discharge control based on the SOC.

[0025] Step 102: When the battery state of charge is less than a first preset charge threshold, the initial torque of the generator is adjusted according to the actual output current and the target output current of the working machine generator to obtain the target torque corresponding to the generator.

[0026] When the work machine is in motion and the battery state of charge is less than a first preset charge threshold (e.g., 85%), the work machine's processor monitors and receives real-time instructions from the air conditioning system. These instructions relate to the air conditioning system's power demand, such as cooling or heating power, or changes in cooling or heating power. Simultaneously, the controller receives engine speed information, which directly affects the generator's power generation. In one embodiment, the generator's initial torque, T, is 9550*P / N, where P represents the cooling or heating power of the air conditioning system and N represents the engine speed.

[0027] The processor of the working machine can calculate the target torque corresponding to the generator based on the deviation between the actual output current of the generator and the target output current using a PID algorithm. It should be noted that in the embodiment of the present invention, it is necessary to ensure the current required by the motor and the excess power generated by the generator before charging the lithium battery.

[0028] Step 103: Send a torque adjustment instruction to the generator; the torque adjustment instruction carries the target torque.

[0029] The electronic device encapsulates the target torque adjusted by the PID algorithm into a torque adjustment instruction, sends the torque instruction to the generator driver, and the generator driver sends the torque adjustment instruction to the generator, thereby controlling the generator to charge the lithium battery and realize timely replenishment of power to the lithium battery.

[0030] Step 104 : Control the generator to operate based on the target torque in response to the torque adjustment instruction to supply power to the battery of the working machine.

[0031] The generator responds to the torque adjustment instruction and operates based on the target torque to supply power to the battery of the working machine, thereby replenishing the battery with electric energy in a timely manner.

[0032] Therefore, when the working machine is in motion, this embodiment of the present invention adjusts the initial torque of the generator based on the actual output current and target output current of the working machine's generator, based on the battery state of charge being less than a first preset charge threshold, to obtain a corresponding target torque for the generator. This control then controls the generator to operate based on the target torque to power the working machine's battery. This embodiment of the present invention accurately and rationally controls the charging and discharging of the working machine's battery based on information such as the working machine's operating conditions and the lithium battery's state of charge, thereby improving the lithium battery's charging and discharging efficiency and lifespan and optimizing overall energy management for the equipment.

[0033] In other aspects of the embodiments of the present invention, step 102, adjusting the initial torque of the generator according to the actual output current and the target output current of the working machine generator to obtain the target torque corresponding to the generator, includes: Based on the deviation value, the preset adjustable proportional variable, the preset adjustable integral variable, the preset first intermediate variable and the preset second intermediate variable, the candidate torque corresponding to the generator is determined; the deviation value is the difference between the target output current and the actual output current, the deviation value, the adjustable proportional variable, the adjustable integral variable and the second intermediate variable are respectively positively correlated with the candidate torque, and the first intermediate variable is negatively correlated with the candidate torque.

[0034] When the candidate torque is less than a preset threshold, the candidate torque, the first intermediate variable, and the second intermediate variable are updated.

[0035] Return step: Based on the deviation value, the preset adjustable proportional variable, the preset adjustable integral variable, the preset first intermediate variable and the preset second intermediate variable, determine the candidate torque corresponding to the generator, until the number of updates reaches the preset number, and determine the last updated candidate torque as the target torque.

[0036] In one embodiment, the generator's target output current is calculated based on the motor's demand current and the battery's demand current. The motor's demand current is calculated based on the total power demand of the electrical loads, the motor's set voltage, and the motor's set power factor. The total power demand of the electrical loads and the motor's demand current are positively correlated, while the motor's set voltage and the motor's set power factor are negatively correlated with the motor's demand current. Specifically, in this embodiment of the present invention, the motor's demand current is determined based on the motor's demand power. The motor is a three-phase AC asynchronous motor, and the power formula for three-phase motors is used for calculation: P = √3*U*I*COSφ, where U represents the motor's set voltage, a constant value. COSφ represents the motor's set power factor, also a constant value. I represents the motor's demand current. The only variable is the total power demand P of the electrical loads. The total power demand P of the electrical loads is the sum of the power of the compressors of the air conditioners in the entire air conditioning system. In this embodiment of the present invention, the total power demand P of the electrical loads is the sum of the power of the compressors of three independent air conditioners. The power of the three air conditioner compressors is the same at all times, so only the power of one air conditioner compressor is required. The power of the compressor is determined by the air conditioning gear set on the display screen. Each air conditioning gear determines a compressor speed, and each speed corresponds to a compressor power. In the embodiment of the present invention, 6 speed gears can be set.

[0037] The battery's demand current is calculated based on a first charge, a set battery charging voltage, and a set battery charging duration. The first charge is positively correlated with the battery's demand current; the set battery charging voltage and the set battery charging duration are each negatively correlated with the battery's demand current. The first charge represents the amount of battery power lost during the previous parking period. Specifically, the battery's demand current is determined by the battery's charge consumed by the parking air conditioner during the previous parking period. For example, the battery's charge consumed during the previous parking period was 70%. To fully charge the battery, 70% of the charge is required during the driving period. Note that for charging safety considerations, charging may be stopped only to a near-full charge (e.g., 90%). The required charge amount is denoted as W. The set battery charging duration can be the duration of the driving period (for example, a day might be 20 hours). However, the program sets the lithium battery to be fully charged in 10 hours. The set charging duration is t. The set charging voltage for the lithium battery is a fixed value. The battery's demand current can be calculated using the formula W / t=UI. It should be noted that the above derivation process is theoretical. In practice, the electricity generated by the generator is used to power both the electric motor and the lithium battery. The embodiments of the present invention prioritize the electric motor's power needs. Even in extreme operating conditions, when the generator's power is insufficient to meet the electric motor's power needs, the lithium battery needs to be discharged appropriately to drive the electric motor to ensure cab cooling during driving.

[0038] The following describes the specific process of calculating the target torque corresponding to the generator by the PID algorithm based on the deviation between the actual output current and the target output current of the generator in the embodiments of the present invention. First, the embodiments of the present invention can set the input variables as follows: ActCur: the actual output current of the generator; TarCur: the target output current of the generator; Kp: the preset adjustable proportional variable in the PID algorithm; Ki: the preset adjustable integral variable in the PID algorithm; TarVoltMaxLim: the maximum voltage limit value. The embodiments of the present invention can set the output variable as follows: TarVolt: the target voltage value. The embodiments of the present invention can set the local variable as follows: rtb_ErrorCur: the difference between the target output current and the actual output current of the generator; rtb_ErrorCur = TarCur - ActCur. The embodiments of the present invention can also set the global variables as follows: Delay_DSTATE (the preset first intermediate variable): the initial value is 0, indicating the compensation value calculated by this program; Delay1_DSTATE (the preset second intermediate variable): the initial value is 0, indicating the compensation value calculated by the previous program. The core algorithm calculation formula of the PID algorithm in the embodiments of the present invention is as follows: TarVolt = (rtb_ErrorCur - Delay_DSTATE) * Kp + rtb_ErrorCur * Ki + Delay1_DSTATE. The TarVolt calculated each time is assigned to the candidate torque. The formulas for updating the candidate torque, the first intermediate variable, and the second intermediate variable are as follows: If TarVolt < TarVoltMaxLim, then TarVolt = TarVoltMaxLim; Delay_DSTATE = rtb_ErrorCur; Delay1_DSTATE = TarVolt. Repeat the above core algorithm calculation formula and the formulas for updating the candidate torque, the first intermediate variable, and the second intermediate variable until the number of updates reaches the preset number of times, and determine the last updated candidate torque as the target torque.

[0039] Therefore, in the driving state of the work machine in the embodiments of the present invention, through precise torque control and PID algorithm adjustment, the charging process of the generator is made more stable and efficient, while reasonably utilizing the power of the engine, optimizing the energy distribution, and improving the overall energy utilization efficiency of the equipment.

[0040] In other aspects of the embodiments of the present invention, after obtaining the state of charge of the battery of the work machine, the method further includes: when the state of charge of the battery is greater than or equal to a second preset state of charge threshold, sending a zero torque command to the generator; the second preset state of charge threshold is less than the first preset state of charge threshold; controlling the generator to stop supplying power to the battery in response to the zero torque command, and controlling the battery to supply power to the motor.

[0041] When the working machine's engine is in driving mode and the battery's state of charge is greater than or equal to a second preset charge threshold (e.g., 80%), the controller sends a zero torque command to the generator driver. Although the generator driver outputs voltage, the generator generates no current in response to the zero torque command due to the lack of torque input. The lithium battery is not charged. The working machine's processor then controls the lithium battery to begin discharging, providing energy to the electric motor, enabling the motor to operate and meet the vehicle's power requirements. It should be noted that in embodiments of the present invention, the lithium battery can be charged and discharged simultaneously.

[0042] When the battery's state of charge (SOC) is greater than or equal to a second preset charge threshold, the system stops charging. When the air conditioner is stopped, the system monitors the motor's operating status to prevent reverse charging and overcharging of the lithium battery. This embodiment of the present invention thus establishes a clear protection strategy for lithium battery overcharging, effectively preventing overcharging under various operating conditions and ensuring the safety and stability of the lithium battery.

[0043] In other aspects of the embodiments of the present invention, the method also includes: when the working machine is in a parking state, the battery charge state of the working machine is greater than or equal to a third set charge threshold, and the battery temperature of the working machine is greater than or equal to a set temperature threshold, controlling the battery to power the electric motor.

[0044] When the work machine is parked, the engine is not operating. When the engine is not operating, the lithium battery's state of charge is greater than or equal to a third set charge threshold (e.g., 20%), and the battery cell temperature is greater than or equal to a set temperature threshold (e.g., -20°C), the work machine's processor controls the lithium battery to begin discharging, providing power to the electric motor, allowing the motor to operate and cool the upper cabin of the cab while the machine is parked. Furthermore, embodiments of the present invention can also meet some basic power needs of the work machine while parked, such as powering vehicle lighting and electric kettles.

[0045] Therefore, the charge and discharge control method of the embodiment of the present invention can dynamically adjust the charge and discharge strategy according to different operating conditions such as driving and parking and the battery charge state of the lithium battery, improve the charge and discharge efficiency of the lithium battery, avoid unnecessary charging and discharging, and help extend the service life of the lithium battery.

[0046] In other aspects of the embodiments of the present invention, before obtaining the battery charge status of the operating machine when the operating machine is in the driving state, it also includes: when the operating machine is in the power-on state, controlling the distribution box circuit to pre-charge the battery; when the battery pre-charging is completed, controlling the battery to be connected to the main circuits of the generator and the motor respectively through the distribution box circuit.

[0047] When the entire working machine is powered on, the machine's Battery Management System (BMS) first pre-charges and pre-discharges the lithium battery by controlling the power distribution box circuit. Specifically, the pre-charge relay in the power distribution box circuit closes, enabling pre-charging of the lithium battery. After pre-charging is complete, the main relay in the power distribution box circuit closes, connecting the lithium battery to the main circuit of the working machine's electrical system. By pre-charging the lithium battery, the embodiments of the present invention ensure that the lithium battery reaches a suitable initial state in advance, ensuring the stability and safety of subsequent charging and discharging.

[0048] In summary, the embodiments of the present invention can accurately and reasonably control the charging and discharging of lithium batteries based on the differences in driving and parking conditions, as well as information such as the battery state of charge (SOC) of the lithium battery, thereby improving the utilization efficiency and life of the lithium battery and optimizing the overall energy management of the equipment.

[0049] Please refer to Figure 2 On the other hand, an embodiment of the present invention further provides a charge and discharge control device, comprising: An acquisition module 210 is configured to acquire a battery state of charge of the operating machine when the operating machine is in a driving state; a calculation module 220 configured to adjust the initial torque of the generator according to the actual output current and the target output current of the generator of the working machine to obtain a target torque corresponding to the generator when the state of charge of the battery is less than a first preset charge threshold; The sending module 230 is configured to send a torque adjustment instruction to the generator; the torque adjustment instruction carries the target torque; The control module 240 is configured to control the generator to operate based on the target torque in response to the torque adjustment instruction to supply power to the battery of the working machine.

[0050] Optionally, adjusting the initial torque of the generator according to the actual output current and the target output current of the working machine generator to obtain the target torque corresponding to the generator includes: determining a candidate torque corresponding to the generator based on a deviation value, a preset adjustable proportional variable, a preset adjustable integral variable, a preset first intermediate variable, and a preset second intermediate variable; the deviation value being a difference between the target output current and the actual output current; the deviation value, the adjustable proportional variable, the adjustable integral variable, and the second intermediate variable being positively correlated with the candidate torque, and the first intermediate variable being negatively correlated with the candidate torque; When the candidate torque is less than a preset threshold, updating the candidate torque, the first intermediate variable, and the second intermediate variable; Return step: Based on the deviation value, the preset adjustable proportional variable, the preset adjustable integral variable, the preset first intermediate variable and the preset second intermediate variable, determine the candidate torque corresponding to the generator, until the number of updates reaches the preset number, and determine the last updated candidate torque as the target torque.

[0051] Optionally, the device further includes: A second control module is configured to send a zero torque command to the generator when the battery state of charge is greater than or equal to a second preset charge threshold; the second preset charge threshold is less than the first preset charge threshold; control the generator to stop supplying power to the battery in response to the zero torque command, and control the battery to supply power to the electric motor.

[0052] Optionally, the device further includes: The third control module is used to control the battery to power the electric motor when the operating machine is in a parking state, the battery charge state of the operating machine is greater than or equal to a third set charge threshold, and the battery temperature of the operating machine is greater than or equal to a set temperature threshold.

[0053] Optionally, the device further includes: The fourth control module is used to control the distribution box circuit to pre-charge the battery when the operating machine is in the power-on state; when the battery pre-charging is completed, the distribution box circuit controls the battery to be connected to the main circuits of the generator and the motor respectively.

[0054] Optionally, the target output current is calculated based on the demand current of the motor and the demand current of the battery; the demand current of the motor is calculated based on the total demand power of electrical consumers, the set voltage of the motor and the set power factor of the motor; the total demand power of electrical consumers and the demand current of the motor are positively correlated; the set voltage of the motor and the set power factor of the motor are negatively correlated with the demand current of the motor, respectively; the demand current of the battery is calculated based on the first power, the set charging voltage of the battery and the set charging time of the battery; the first power and the demand current of the battery are positively correlated; the set charging voltage of the battery and the set charging time of the battery are negatively correlated with the demand current of the battery, respectively; the first power represents the power lost by the battery during the last parking period.

[0055] The charge and discharge control device includes a processor and a memory. The acquisition module 210, calculation module 220, sending module 230 and control module 240 are all stored in the memory as program units, and the processor executes the program units stored in the memory to implement corresponding functions.

[0056] The processor includes a kernel, which retrieves the corresponding program unit from the memory. There can be one or more kernels.

[0057] The memory may include non-permanent memory in a computer-readable medium, random access memory (RAM) and / or non-volatile memory, such as read-only memory (ROM) or flash RAM, and the memory includes at least one memory chip.

[0058] Figure 3 An example of a physical structure diagram of a working machine is shown below. Figure 3 As shown, the working machine may include: a processor 310, a communication interface 320, a memory 330, and a communication bus 340, wherein the processor 310, the communication interface 320, and the memory 330 communicate with each other via the communication bus 340. The processor 310 may call logic instructions in the memory 330 to execute a charge and discharge control method, which includes: obtaining the battery state of charge of the working machine when the working machine is in a driving state; adjusting the initial torque of the generator according to the actual output current and the target output current of the working machine generator to obtain the target torque corresponding to the generator when the battery state of charge is less than a first preset charge threshold; sending a torque adjustment instruction to the generator; the torque adjustment instruction carries the target torque; and controlling the generator to respond to the torque adjustment instruction and operate based on the target torque to power the battery of the working machine.

[0059] Furthermore, the logic instructions in the aforementioned memory 330 can be implemented as software functional units and, when sold or used as independent products, can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, or the portion that contributes to the prior art, or a portion of the technical solution, can be embodied in the form of a software product. This computer software product, stored in a storage medium, includes several instructions for enabling a computer device (which can be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as a USB flash drive, a mobile hard drive, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk.

[0060] Please refer to Figure 4 The operating machine further includes a generator driver 410 and a battery 420 electrically connected to the processor (or controller), a generator 430 electrically connected to the generator driver 410, and an electric motor 440 electrically connected to the battery 420; the generator driver 410 is used to control the generator 430 to operate based on the target torque; the generator 430 is used to power the battery when the operating machine is in a driving state; the battery 420 is used to power the electric motor 440; and the electric motor 440 is used to power electrical appliances of the operating machine.

[0061] Specifically, in one embodiment, please refer to Figure 4An operating machine (e.g., an excavator) according to an embodiment of the present invention includes a generator driver 410, a battery 420, a generator 430, a motor 440, an engine 450, a processor 310 (or controller 310), a display screen 460, a power distribution box circuit 470, a motor driver 480, a pulley 490, and an air conditioner compressor 491. The processor 310 is electrically connected to the generator driver 410, the motor driver 480, and the display screen 460, providing overall control. The power distribution box circuit 470 is electrically connected to the generator driver 410, the motor driver 480, and the battery 420. The power distribution box circuit 470 controls the connection between the battery 420 and the generator driver 410 via main relay 1 and the motor driver 480 via main relay 2. The power distribution box circuit 470 also includes a pre-charge relay for pre-charging the battery 420. The generator driver 410 is the drive circuit for the generator 430, controlling the generator 430 to operate according to a target torque to generate electrical energy. Generator driver 410 also converts the AC power output by generator 430 into DC power. Motor driver 480 is the drive circuit for motor 440, controlling motor 440 to generate mechanical energy from the electrical energy provided by battery 420, thereby driving pulley 490 to rotate and provide energy for the air conditioner's compressor 491. Motor driver 480 also converts the DC power output by battery 420 into AC power. Generator 430 can be a water-cooled permanent magnet synchronous generator 430, and motor 440 can be a water-cooled permanent magnet synchronous motor 440. Batteries 420 can be made of various commercially available materials, such as lithium batteries. The number of air conditioner compressors 491 can be adjusted based on actual needs. For example, if three air conditioners are installed, three compressors 491 will be provided.

[0062] When the machine is in driving condition: 1. After the entire operating machine is powered on, the machine's Battery Management System (BMS) first pre-charges and pre-discharges the lithium battery by controlling the power distribution box circuit 470. Specifically, the pre-charge relay of the power distribution box circuit 470 closes, enabling the lithium battery to be pre-charged. After pre-charging is complete, the power distribution box circuit 470 closes main relays 1 and 2, connecting the lithium battery to the main circuit of the operating machine's electrical system. This embodiment of the present invention pre-charges the lithium battery to a suitable initial state, ensuring the stability and safety of subsequent charging and discharging.

[0063] 2. When the machine's engine 450 is operating and the lithium battery's state of charge is less than 85%, processor 310 (controller) receives commands from the air conditioning system, engine 450 speed information, and the actual and target output currents of generator 430. Processor 310 then calculates the initial torque based on the air conditioning system command and engine 450 speed information. It then uses a proportional-integral (PID) algorithm to calculate the target torque based on the actual and target output currents of generator 430. It then sends a torque adjustment command to generator driver 410, which in turn charges the lithium battery.

[0064] 3. When the engine 450 is running and the battery state of charge of the lithium battery is greater than or equal to 80%: the processor 310 of the working machine sends a zero torque command to the generator driver 410. At this time, the generator driver 410 has voltage but no current, and the lithium battery is discharged to supply power to the motor 440.

[0065] 4. Lithium battery protection strategy for driving discharge: When the battery state of charge is less than 85%, charging is required; when the battery state of charge is greater than or equal to 80%, charging is stopped to prevent the electric motor 440 from reverse charging when the air conditioner is stopped, causing the lithium battery to be overcharged.

[0066] When the machine is in the parking position: When the engine is not working, the battery state of charge of the lithium battery is greater than or equal to 20% and the battery cell temperature is greater than or equal to -20°C, the lithium battery discharges to supply power to the motor.

[0067] The lithium battery charge and discharge control strategy of the operating machinery of the present invention can dynamically adjust the charge and discharge strategy according to different operating conditions such as driving and parking and the real-time battery charge state of the lithium battery, thereby improving the charge and discharge efficiency of the lithium battery, avoiding unnecessary charging and discharging, and helping to extend the service life of the lithium battery. During driving, through precise torque control and PID algorithm adjustment, the charging process of the generator is made more stable and efficient, while the engine power is rationally utilized, energy distribution is optimized, and the overall energy utilization efficiency of the equipment is improved. A clear protection strategy has been formulated to address the problem of lithium battery overcharging, which can effectively prevent lithium battery overcharging under different operating conditions, thereby ensuring the safety and stability of the lithium battery.

[0068] On the other hand, the present invention also provides a computer program product, which includes a computer program, which can be stored on a machine-readable storage medium. When the computer program is executed by a processor, the computer can execute a charge and discharge control method, which includes: when the working machine is in a driving state, obtaining the battery charge state of the working machine; when the battery charge state is less than a first preset charge threshold, adjusting the initial torque of the generator according to the actual output current and target output current of the working machine generator to obtain the target torque corresponding to the generator; sending a torque adjustment instruction to the generator; the torque adjustment instruction carries the target torque; controlling the generator to respond to the torque adjustment instruction and operate based on the target torque to power the battery of the working machine.

[0069] On the other hand, the present invention also provides a machine-readable storage medium having a computer program stored thereon, which is implemented by a processor to perform a charge and discharge control method, the method comprising: when the working machine is in a driving state, obtaining the battery charge state of the working machine; when the battery charge state is less than a first preset charge threshold, adjusting the initial torque of the generator according to the actual output current and target output current of the working machine generator to obtain the target torque corresponding to the generator; sending a torque adjustment instruction to the generator; the torque adjustment instruction carries the target torque; controlling the generator to respond to the torque adjustment instruction and operate based on the target torque to power the battery of the working machine.

[0070] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, i.e., they may be located in one location or distributed across multiple network units. Some or all of the modules may be selected based on actual needs to achieve the objectives of the present embodiment. Persons of ordinary skill in the art will be able to understand and implement the present invention without inventive effort.

[0071] Through the above description of the embodiments, those skilled in the art will clearly understand that each embodiment can be implemented using software plus a necessary general-purpose hardware platform, or of course, hardware. Based on this understanding, the essence of the above technical solution, or the portion that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, a magnetic disk, or an optical disk, and includes a number of instructions for causing a computer device (such as a personal computer, server, or network device) to execute the methods described in each embodiment or certain portions of the embodiments.

[0072] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A charge and discharge control method, characterized in that: include: When the working machine is in a driving state, obtaining a battery state of charge of the working machine; When the battery state of charge is less than a first preset charge threshold, adjusting the initial torque of the generator according to the actual output current and the target output current of the generator of the working machine to obtain a target torque corresponding to the generator; sending a torque adjustment instruction to the generator; the torque adjustment instruction carries the target torque; The generator is controlled to operate to supply power to a battery of the work machine based on the target torque in response to the torque adjustment command.

2. The method according to claim 1, characterized in that The adjusting the initial torque of the generator according to the actual output current and the target output current of the working machine generator to obtain the target torque corresponding to the generator includes: determining a candidate torque corresponding to the generator based on a deviation value, a preset adjustable proportional variable, a preset adjustable integral variable, a preset first intermediate variable, and a preset second intermediate variable; the deviation value being a difference between the target output current and the actual output current; the deviation value, the adjustable proportional variable, the adjustable integral variable, and the second intermediate variable being positively correlated with the candidate torque, and the first intermediate variable being negatively correlated with the candidate torque; When the candidate torque is less than a preset threshold, updating the candidate torque, the first intermediate variable, and the second intermediate variable; Return step: Based on the deviation value, the preset adjustable proportional variable, the preset adjustable integral variable, the preset first intermediate variable and the preset second intermediate variable, determine the candidate torque corresponding to the generator, until the number of updates reaches the preset number, and determine the last updated candidate torque as the target torque.

3. The method according to claim 1, characterized in that After obtaining the battery state of charge of the working machine, the method further includes: sending a zero torque command to the generator when the battery state of charge is greater than or equal to a second preset charge threshold; the second preset charge threshold is less than the first preset charge threshold; The generator is controlled to stop supplying power to the battery in response to the zero torque command, and the battery is controlled to supply power to the electric motor.

4. The method according to claim 1, wherein The method further comprises: When the working machine is in a parked state, the battery state of the working machine is greater than or equal to a third set charge threshold, and the battery temperature of the working machine is greater than or equal to a set temperature threshold, the battery is controlled to power the electric motor.

5. The method according to claim 1, wherein Before obtaining the battery state of the working machine when the working machine is in the driving state, the method further includes: When the operating machine is powered on, controlling the power distribution box circuit to pre-charge the battery; When the battery pre-charging is completed, the battery is controlled by the distribution box circuit to be connected to the main circuits of the generator and the motor respectively.

6. The method according to claim 1, characterized in that The target output current is calculated based on the demand current of the motor and the demand current of the battery; the demand current of the motor is calculated based on the total demand power of the electrical appliances, the set voltage of the motor, and the set power factor of the motor; the total demand power of the electrical appliances and the demand current of the motor are positively correlated; the set voltage of the motor and the set power factor of the motor are respectively negatively correlated with the demand current of the motor; the demand current of the battery is calculated based on the first power level, the set charging voltage of the battery, and the set charging time of the battery; There is a positive correlation between the first electrical quantity and the required current of the battery; The set charging voltage of the battery and the set charging time of the battery are respectively negatively correlated with the required current of the battery; The first power level represents the power consumed by the battery during a previous parking period.

7. A charge and discharge control device, characterized in that: include: An acquisition module, configured to acquire a battery state of charge of the operating machine when the operating machine is in a driving state; a calculation module, configured to adjust the initial torque of the generator according to the actual output current and the target output current of the generator of the working machine to obtain a target torque corresponding to the generator when the state of charge of the battery is less than a first preset charge threshold; a sending module, configured to send a torque adjustment instruction to the generator; The torque adjustment instruction carries the target torque; A control module is configured to control the generator to operate based on the target torque in response to the torque adjustment command to supply power to a battery of the work machine.

8. A working machine comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein: When the processor executes the program, the charge and discharge control method according to any one of claims 1 to 6 is implemented.

9. The working machine according to claim 8, characterized in that: The work machine further includes a generator driver and a battery electrically connected to the processor, a generator electrically connected to the generator driver, and an electric motor electrically connected to the battery; The generator driver is used to control the generator to operate based on the target torque; The generator is used to supply power to the battery when the operating machine is in a driving state; The battery is used to power the electric motor; The electric motor is used to supply power to electrical appliances of the operating machine.

10. A machine-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the charge and discharge control method according to any one of claims 1 to 6 is implemented.

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