Motor control method and motor control system for construction machinery

Abstract

The invention relates to the technical field of engineering machinery, and provides a motor control method and system for engineering machinery, and the method comprises the steps: determining a total current allowable value of a DC side of a whole vehicle according to the fusing current of a battery fuse; calculating the total current budget of all walking motor controllers based on the total current allowable value and the real-time working current of the oil pump motor controller; and distributing a direct current side current limit value corresponding to each walking motor controller according to the total current budget, and issuing the direct current side current limit value to the corresponding walking motor controller, so that the walking motor controller controls the output torque according to the direct current side current limit value. According to the invention, when the total current is limited, the current demand of the oil pump motor is guaranteed preferentially, so that the continuity of core operation actions such as excavation and lifting is ensured, smooth intervention can be carried out before the total current is close to a safety threshold, fundamental protection jump from passive fusing to active prevention is realized, and the safety of the oil pump motor is ensured. And the operation safety and reliability of the whole vehicle under complex working conditions are improved.

Description

Technical Field

[0001] This invention relates to the field of engineering machinery technology, specifically to a motor control method and a motor control system for engineering machinery. Background Technology

[0002] In large electric construction machinery (such as boom lifts, electric excavators, loaders, etc.), the power system is typically powered by a high-voltage battery, which distributes power to multiple motor controllers via a DC bus. A typical configuration includes one or more high-power hydraulic pump motor controllers (driving the hydraulic system) and multiple (usually two or four) travel motor controllers. All these controllers are connected in parallel to a common DC bus, with a high-capacity fuse at the bus inlet to protect the battery.

[0003] When construction machinery performs combined actions (e.g., a boom lift simultaneously moving and raising the boom), the hydraulic pump motor and multiple travel motors may simultaneously demand peak power, causing a sharp increase in the total DC current drawn from the battery. Since the fuse's blowing current is fixed, this instantaneous or continuous high current can easily cause the fuse to overheat and blow. Once the fuse blows, the entire machine will lose power completely, potentially leading to serious safety accidents and significant economic losses at the work site (especially in hazardous conditions such as ramps and mines).

[0004] In related technologies, to achieve fuse blowout protection, the general approach is to monitor the total DC current and directly cut off all motor power when it exceeds a threshold. While this method protects the fuse, it causes a sudden interruption of the entire machine's power, severely impacting operational safety and user experience. Summary of the Invention

[0005] To solve the above-mentioned technical problems, the first objective of this invention is to provide a motor control method for engineering machinery.

[0006] The second objective of this invention is to provide a motor control system for engineering machinery.

[0007] The technical solution adopted in this invention is as follows:

[0008] An embodiment of the first aspect of the present invention provides a motor control method for engineering machinery, comprising: determining the total allowable current value of the DC side of the vehicle based on the fusing current of the battery fuse and a preset safety margin; obtaining the real-time operating current of the oil pump motor controller; calculating the total current budget of all travel motor controllers based on the total allowable current value and the real-time operating current of the oil pump motor controller; allocating the corresponding DC side current limit value to each travel motor controller according to the total current budget, and issuing it to the corresponding travel motor controller so that the travel motor controller controls the output torque according to the DC side current limit value.

[0009] The motor control method for engineering machinery proposed above in this invention may also have the following additional technical features:

[0010] According to one embodiment of the present invention, the total current budget for all walking motor controllers is calculated specifically according to the following formula: I _walk_motor =I _limit_total -I _pump_motor Among them, I _walk_motor For the total current budget, I _limit_total I is the total allowable current value. _pump_motor This refers to the real-time operating current of the oil pump motor controller.

[0011] According to one embodiment of the present invention, the walking motor controller controls the output torque based on the DC-side current limit value, specifically including: the walking motor controller acquiring the input current drawn from the DC bus in real time, using the DC-side current limit value as the target current value and the input current drawn from the DC bus as the feedback current value, and inputting it into the DC-side current loop PI (Proportional Integral) controller, so that the DC-side current loop PI controller outputs a torque limit coefficient, the torque limit coefficient being in the range of (0, 1); the walking motor controller acquiring the actual motor speed in real time, using the actual motor speed as the feedback speed value and the reference speed as the target speed value, and inputting it into the speed loop PI controller, so that the speed loop PI controller outputs an initial torque command; the walking motor controller outputs a final torque command based on the torque limit coefficient and the initial torque command.

[0012] According to one embodiment of the present invention, the DC-side current loop PI controller outputs a torque limiting coefficient, specifically including: when the input current is less than or equal to the DC-side current limiting value, the output torque limiting coefficient is 1; when the input current is greater than the DC-side current limiting value, the value of the torque limiting coefficient is reduced according to the deviation between the input current and the DC-side current limiting value.

[0013] According to one embodiment of the present invention, the dynamic response priority of the DC-side current loop PI controller is configured to be no lower than the dynamic response priority of the speed loop PI controller.

[0014] A second aspect of the present invention provides a motor control system for engineering machinery, comprising: a main controller, configured to determine the total allowable current value of the DC side of the vehicle based on the fusing current of the battery fuse and a preset safety margin, acquire the real-time operating current of the oil pump motor controller, calculate the total current budget of all travel motor controllers based on the total allowable current value and the real-time operating current of the oil pump motor controller, allocate the corresponding DC side current limit value to each travel motor controller according to the total current budget, and send it to the corresponding travel motor controller; an oil pump motor controller, configured to report its real-time operating current to the main controller; and travel motor controllers, configured to receive their respective corresponding DC side current limit values ​​and control the output torque according to the DC side current limit values.

[0015] The motor control system for the engineering machinery described above in this invention also has the following additional technical features:

[0016] According to one embodiment of the present invention, the main controller specifically calculates the total current budget of all walking motor controllers according to the following formula: I _walk_motor =I _limit_total -I _pump_motor Among them, I _walk_motor For the total current budget, I _limit_total I is the total allowable current value. _pump_motor This refers to the real-time operating current of the oil pump motor controller.

[0017] According to one embodiment of the present invention, the walking motor controller is specifically configured to: acquire in real time the input current drawn from the DC bus, use the DC side current limit value as the target current value, and use the input current drawn from the DC bus as the feedback current value, and input it to the DC side current loop PI controller so that the DC side current loop PI controller outputs a torque limit coefficient, the torque limit coefficient being in the range of (0, 1); acquire in real time the actual motor speed, use the actual motor speed as the feedback speed value, and use the reference speed as the target speed value, and input it to the speed loop PI controller so that the speed loop PI controller outputs an original torque command; and output a final torque command based on the torque limit coefficient and the original torque command.

[0018] According to one embodiment of the present invention, the DC-side current loop PI controller is specifically configured to: output a torque limiting coefficient of 1 when the input current is less than or equal to the DC-side current limit value; and reduce the value of the torque limiting coefficient according to the deviation between the input current and the DC-side current limit value when the input current is greater than the DC-side current limit value.

[0019] According to one embodiment of the present invention, the dynamic response priority of the DC-side current loop PI controller is configured to be no lower than the dynamic response priority of the speed loop PI controller.

[0020] The beneficial effects of this invention are:

[0021] This invention prioritizes the current demand of the oil pump motor when the total current is limited, thereby ensuring the continuity of core operations such as digging and lifting. It achieves an optimal balance between safety and operational efficiency. Furthermore, by proactively and dynamically allocating the current budget, it can smoothly intervene before the total current approaches the safety threshold. Its response speed is faster than the heat accumulation process of the fuse, fundamentally avoiding unexpected fuse blowouts. This represents a fundamental leap in protection from "passive blowout" to "active prevention," enhancing the operational safety and reliability of the entire vehicle under complex working conditions.

[0022] The local walking motor controller adopts a dual closed-loop algorithm. Based on the allocated DC-side current limit value, it outputs a torque limit coefficient. This coefficient is multiplied by the torque command output by the speed loop to achieve priority limitation of torque by the DC-side current loop. Furthermore, through carefully tuned local current loop PI parameters, the torque limit coefficient can be continuously changed, avoiding sudden power interruption or mechanical shock caused by traditional shutdown or step current limiting. The entire protection process is smooth, providing a good user experience. Attached Figure Description

[0023] Figure 1 This is a flowchart of a motor control method for engineering machinery according to an embodiment of the present invention;

[0024] Figure 2 This is a schematic diagram of the architecture of an engineering machine according to an embodiment of the present invention;

[0025] Figure 3 This is a schematic diagram illustrating the generation principle of torque commands according to an embodiment of the present invention;

[0026] Figure 4 This is a block diagram of a motor control system for engineering machinery according to an embodiment of the present invention. Detailed Implementation

[0027] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0028] Figure 1This is a flowchart of a motor control method for construction machinery according to an embodiment of the present invention. The construction machinery can be based on... Figure 2 The architecture shown includes: battery E, fuse FU, contactor S, and one oil pump motor controller (main pump) and multiple travel motor controllers ( Figure 2 (Taking 4 as an example), where battery E is directly connected to fuse FU, contactor S is connected to the back-end controller after it is energized, B+ is the positive terminal of the battery, B- is the negative terminal of the battery, and the oil pump motor controller, because it usually has the highest power and needs to work continuously, has the natural conditions to act as a coordination center, and communicates with the 4 walking motor controllers through the CAN (Controller Area Network) bus.

[0029] like Figure 1 As shown, the motor control method for engineering machinery in this embodiment of the invention may include the following steps:

[0030] S1, based on the fusing current of the battery fuse and the preset safety margin, determine the total allowable current I on the DC side of the vehicle. _limit_total .

[0031] Specifically, I _limit_total = Fusing current of the battery fuse × preset safety margin. The preset safety margin is determined based on the fuse's fusing characteristic curve, the load fluctuation coefficient of the engineering machinery (load fluctuation ≤15% under actual combined working conditions), and necessary design redundancy, preferably 0.95, to ensure sufficient safety margin under instantaneous peak load. Typically, the preset safety margin is between 0.8 and 0.95 to ensure that the instantaneous peak value of the total DC current has a sufficient safety boundary when the load fluctuates instantaneously (e.g., ≤15%), preventing the fuse from triggering its fusing delay.

[0032] S2, obtain the real-time operating current I of the oil pump motor controller. _pump_motor .

[0033] S3, based on the total current allowable value I _limit_total Real-time operating current I of the oil pump motor controller _pump_motor Calculate the total current budget I for all walking motor controllers. _walk_motor .

[0034] In one embodiment of the present invention, the total current budget for all walking motor controllers is calculated specifically according to the following formula:

[0035] I _walk_motor =I _limit_total -I _pump_motor ;

[0036] Among them, I _walk_motor For the total current budget, I_limit_total I is the allowable total current value. _pump_motor This is the real-time operating current of the oil pump motor controller.

[0037] S4, based on the total current budget I _walk_motor Assign DC-side current limit values ​​I to each travel motor controller _limit_per_wheel And send it to the corresponding travel motor controller, so that the travel motor controller can determine the DC side current limit value I. _limit_per_wheel Control the output torque.

[0038] Specifically, the total current budget I _walk_motor The DC-side current limit value I is allocated to each walking motor controller. _limit_per_wheel The DC-side current limit value I can be assigned to each walking motor controller in any of the following ways. _limit_per_wheel :

[0039] a) Average distribution: Allocate the total current budget I _walk_motor Divide by the number of travel motor controllers to obtain the DC-side current limit value I for each controller. _limit_per_whee ;

[0040] b) As-needed allocation: The total current budget is dynamically allocated according to the real-time speed, load or torque command ratio of each travel motor. For example, in the steering travel condition, based on the steering angle sensor signal, the current limit value of 1.2-1.5 times that of the inner motor is allocated to the outer travel motor to ensure steering capability.

[0041] DC side current limit value I _limit_per_wheel Coordination commands are sent to each travel motor controller via CAN broadcast or point-to-point transmission. The travel motor controller receives its corresponding DC-side current limit value I. _limit_per_wheel The motor torque output is dynamically adjusted through closed-loop control. This prioritizes the current demand of the oil pump motor when total current is limited, ensuring the continuity of core operations such as digging and lifting. It achieves an optimal balance between safety and operational efficiency. Furthermore, by proactively and dynamically allocating the current budget, it can smoothly intervene before the total current approaches the safety threshold, responding faster than the heat accumulation process of a fuse. This fundamentally avoids unexpected fuse blowouts, representing a significant leap from "passive blowing" to "active prevention," thus enhancing the overall operational safety and reliability of the vehicle under complex working conditions.

[0042] In a specific embodiment of the present invention, the walking motor controller controls the output torque according to the DC side current limit value, specifically including the following steps S41-S43:

[0043] S41, the walking motor controller obtains the input current I drawn from the DC bus in real time._dc_local With DC side current limit value I _limit_per_wheel The target current value is the input current I drawn from the DC bus. _dc_local The feedback current value is input to the DC-side current loop PI controller so that the DC-side current loop PI controller outputs the torque limiting coefficient k, and the range of the torque limiting coefficient k is (0, 1).

[0044] S42, the walking motor controller obtains the actual motor speed S in real time. pd_real Based on the actual speed S of the motor pd_real To provide feedback on the rotational speed, the reference rotational speed S is used. pd_ref The target speed value is input into the speed loop PI controller, so that the speed loop PI controller outputs the original torque command T. _demand .

[0045] S43, the travel motor controller determines the torque limit coefficient k and the original torque command T based on the torque command T. _demand Output final torque command T _final .

[0046] Specifically, such as Figure 3 As shown, the current loop PI controller uses the DC-side current limit value I _limit_per_wheel The target current value is the input current I drawn from the DC bus. _dc_local The feedback current value is used to output the torque limiting coefficient k through closed-loop calculation. The speed loop PI controller uses the actual motor speed S. pd_real To provide feedback on the rotational speed, the reference rotational speed S is used. pd_ref For the target speed value, output the original torque command T. _demand Ultimately, the walking motor controller, based on T... _final =T _demand × k outputs the final torque command T _final Therefore, the local walking motor controller adopts a dual closed-loop algorithm. Based on the allocated DC-side current limit value, it outputs a torque limit coefficient. This coefficient is multiplied by the torque command output by the speed loop to achieve priority limitation of torque by the DC-side current loop. Furthermore, through carefully tuned local current loop PI parameters, the torque limit coefficient can be continuously changed, avoiding sudden power interruption or mechanical shock caused by traditional shutdown or step current limiting. The entire protection process is smooth, providing a good user experience.

[0047] In one embodiment of the present invention, the DC-side current loop PI controller outputs a torque limiting coefficient, specifically including: when the input current I... _dc_local Less than or equal to the DC side current limit value I _limit_per_wheel When the output torque limiting coefficient k is 1, the input current I... _dc_local Greater than the DC side current limit value I _limit_per_wheelAt that time, according to the input current I _dc_local With DC side current limit value I _limit_per_wheel The deviation reduces the value of the torque limiting coefficient k.

[0048] Specifically, when I _dc_local ≤I _limit_per_wheel When I saturates, the output k is 1; when I _dc_local > I _limit_per_wheel At that time, according to I _limit_per_wheel with I _dc_local The negative deviation dynamically decreases from 1 to the value of k, and the value of k is related to I. _limit_per_wheel with I _dc_local The difference can be inversely proportional, and the specific slope can be set in advance so that the torque limit coefficient can change continuously, thus achieving a smooth torque transition.

[0049] In an embodiment of the present invention, the dynamic response priority of the DC-side current loop PI controller is configured to be no lower than the dynamic response priority of the speed loop PI controller, ensuring that once the local DC current exceeds the limit, the speed requirement can be immediately covered and the current protection is executed first.

[0050] To enable those skilled in the art to better understand the present invention, the above-described motor control method of the present invention will be described below with reference to specific examples.

[0051] The battery fuse has a fusing current of 500A, and the total current allowable value I... _limit_total The current is set to 500A × 0.95 = 475A. When the boom is simultaneously traveling and climbing on a slope (high torque) and rapidly lifting the boom (high load on the hydraulic pump), the initial real-time operating current of the hydraulic pump motor controller is 75A. The total current budget I for all travel motor controllers is calculated. _walk_motor The current limit is 400A, and each walking motor controller is allocated a DC-side current limit of 100A. _limit_per_wheel When the operator suddenly increases the lifting force of the boom, the real-time operating current I of the oil pump motor controller... _pump_motor Instantly rises to 115A, recalculate: I _walk_motor =475A-115A=360A, I _limit_per_wheel =90A is sent to each travel motor controller. After receiving the new and stricter limit value (90A), each travel controller quickly activates its local DC side current loop to reduce the torque limit coefficient k, so that the torque of each motor decreases smoothly.

[0052] As a result, the total current was successfully limited to around 475A. The boom lift's climbing speed slowed down due to the decrease in torque, dropping from the original climbing speed of 600 rpm to 460 rpm. However, the power was not interrupted, and the boom lifting action was prioritized. The operator's hands felt a smooth transition in power distribution, rather than a malfunction.

[0053] In summary, the motor control method for construction machinery according to embodiments of the present invention can prioritize the current demand of the oil pump motor when the total current is limited, thereby ensuring the continuity of core operations such as digging and lifting, achieving an optimal balance between safety and operational efficiency. Furthermore, by proactively and dynamically allocating the current budget, it can smoothly intervene before the total current approaches the safety threshold, with a response speed faster than the thermal accumulation process of fuses. This fundamentally avoids unexpected fuse blowouts, achieving a fundamental leap in protection from "passive blowing" to "active prevention," improving the operational safety and reliability of the entire vehicle under complex working conditions. The local travel motor controller employs a dual closed-loop algorithm, outputting a torque limit coefficient based on the allocated DC-side current limit value. This coefficient is multiplied by the torque command output by the speed loop to achieve priority limitation of torque by the DC-side current loop. Moreover, through carefully tuned local current loop PI parameters, the torque limit coefficient can be continuously varied, avoiding sudden power interruption or mechanical shock caused by traditional shutdown or step-like current limiting. The entire protection process is smooth, providing a good user experience.

[0054] Corresponding to the aforementioned motor control method for construction machinery, this invention also proposes a motor control system for construction machinery. Since the system embodiments of this invention correspond to the aforementioned method embodiments, details not disclosed in the system embodiments can be found in the aforementioned method embodiments, and will not be repeated here.

[0055] Figure 4 This is a block diagram of a motor control system for engineering machinery according to an embodiment of the present invention, as shown below. Figure 4 As shown, the motor control system of this construction machinery includes: a main controller, an oil pump motor controller, and a travel motor controller.

[0056] The main controller is used to determine the total allowable current I on the DC side of the vehicle based on the fusing current of the battery fuse and the preset safety margin. _limit_total Obtain the real-time operating current I of the oil pump motor controller. _pump_motor Based on the total current allowable value I _limit_total Real-time operating current I of the oil pump motor controller _pump_motor Calculate the total current budget I for all walking motor controllers. _walk_motor According to the total current budget I _walk_motor Assign DC-side current limit values ​​I to each travel motor controller _limit_per_wheelThe data is then sent to the corresponding walking motor controller; the oil pump motor controller is used to report its real-time operating current I. _walk_motor The main controller; the walking motor controller is used to receive its respective DC-side current limit value I. _limit_per_wheel And according to the DC side current limit value I _limit_per_wheel Control the output torque.

[0057] According to one embodiment of the present invention, the main controller specifically calculates the total current budget of all walking motor controllers according to the following formula: I _walk_motor =I _limit_total -I _pump_motor Among them, I _walk_motor For the total current budget, I _limit_total I is the allowable total current value. _pump_motor This is the real-time operating current of the oil pump motor controller.

[0058] The main controller function can be implemented by the VCU (Vehicle Control Unit).

[0059] According to one embodiment of the present invention, the walking motor controller is specifically used to: acquire in real time the input current I drawn from the DC bus. _dc_local With DC side current limit value I _limit_per_wheel The target current value is the input current I drawn from the DC bus. _dc_local The feedback current value is input to the DC-side current loop PI controller so that the DC-side current loop PI controller outputs a torque limiting coefficient k, the range of which is (0, 1]. The actual motor speed S is acquired in real time. pd_real Based on the actual speed S of the motor pd_real To provide feedback on the rotational speed, the reference rotational speed S is used. pd_ref The target speed value is input into the speed loop PI controller, so that the speed loop PI controller outputs the original torque command T. _demand Based on the torque limit factor k and the original torque command T _demand Output final torque command T _final .

[0060] According to one embodiment of the present invention, the DC-side current loop PI controller is specifically used to: when the input current I... _dc_local Less than or equal to the DC side current limit value I _limit_per_wheel When the input current I is at that time, the output torque limiting factor is 1; when the input current I is at that time, the output torque limiting factor is 1. _dc_local Greater than the DC side current limit value I _limit_per_wheel At that time, according to the input current I _dc_local With DC side current limit value I _limit_per_wheel The deviation reduces the value of the torque limiting coefficient k.

[0061] According to one embodiment of the present invention, the dynamic response priority of the DC-side current loop PI controller is configured to be no lower than the dynamic response priority of the speed loop PI controller.

[0062] The motor control system of the construction machinery according to embodiments of the present invention can prioritize the current demand of the oil pump motor when the total current is limited, thereby ensuring the continuity of core operations such as digging and lifting, achieving an optimal balance between safety and work efficiency. Furthermore, by proactively and dynamically allocating the current budget, it can smoothly intervene before the total current approaches the safety threshold, with a response speed faster than the thermal accumulation process of fuses. This fundamentally avoids unexpected fuse blowing, achieving a fundamental leap in protection from "passive blowing" to "active prevention," improving the operational safety and reliability of the entire vehicle under complex working conditions. The local travel motor controller adopts a dual closed-loop algorithm, outputting a torque limiting coefficient based on the allocated DC-side current limit value. This coefficient is multiplied by the torque command output by the speed loop to achieve priority limiting of torque by the DC-side current loop. Through carefully tuned local current loop PI parameters, the torque limiting coefficient can change continuously, avoiding sudden power interruption or mechanical shock caused by traditional shutdown or step-like current limiting. The entire protection process is smooth, providing a good user experience.

[0063] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0064] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0065] Any process or method description in the flowchart or otherwise herein can be understood as representing a module, segment, or portion of code comprising one or more executable instructions for implementing custom logic functions or processes, and the scope of preferred embodiments of the invention includes additional implementations in which functions may be performed not in the order shown or discussed, including substantially simultaneously or in reverse order depending on the functions involved, as will be understood by those skilled in the art to which embodiments of the invention pertain.

[0066] Those skilled in the art will understand that all or part of the steps of the methods described in the above embodiments can be implemented by a program instructing related hardware, and the program can be stored in a computer-readable storage medium. When executed, the program includes one or a combination of the steps of the method embodiments.

[0067] Furthermore, the functional units in the various embodiments of the present invention can be integrated into a processing module, or each unit can exist physically separately, or two or more units can be integrated into a module. The integrated module can be implemented in hardware or as a software functional module. If the integrated module is implemented as a software functional module and sold or used as an independent product, it can also be stored in a computer-readable storage medium.

[0068] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A method for controlling the motor of engineering machinery, characterized in that, include: Determine the total allowable current on the DC side of the vehicle based on the fusing current of the battery fuse and the preset safety margin. Obtain the real-time operating current of the oil pump motor controller; Based on the total allowable current value and the real-time operating current of the oil pump motor controller, calculate the total current budget for all travel motor controllers; The DC-side current limit value is allocated to each walking motor controller according to the total current budget, and then sent to the corresponding walking motor controller so that the walking motor controller controls the output torque according to the DC-side current limit value.

2. The motor control method for engineering machinery according to claim 1, characterized in that, The total current budget for all walking motor controllers is calculated using the following formula: I _walk_motor =I _limit_total -I _pump_motor ; Among them, I _walk_motor For the total current budget, I _limit_total I is the total allowable current value. _pump_motor This refers to the real-time operating current of the oil pump motor controller.

3. The motor control method for engineering machinery according to claim 1, characterized in that, The walking motor controller controls the output torque according to the DC side current limit value, specifically including: The walking motor controller obtains the input current drawn from the DC bus in real time, uses the DC side current limit value as the target current value, and uses the input current drawn from the DC bus as the feedback current value, and inputs it to the DC side current loop PI controller so that the DC side current loop PI controller outputs a torque limit coefficient, the range of which is (0, 1]. The walking motor controller acquires the actual motor speed in real time, uses the actual motor speed as the feedback speed value and the reference speed as the target speed value, and inputs it to the speed loop PI controller so that the speed loop PI controller outputs the original torque command; The walking motor controller outputs the final torque command based on the torque limit coefficient and the original torque command.

4. The motor control method for engineering machinery according to claim 3, characterized in that, The output torque limiting coefficient of the DC-side current loop PI controller specifically includes: When the input current is less than or equal to the DC side current limit value, the output torque limit coefficient is 1; When the input current is greater than the DC-side current limit value, the value of the torque limit coefficient is reduced according to the deviation between the input current and the DC-side current limit value.

5. The motor control method for engineering machinery according to claim 3, characterized in that, The dynamic response priority of the DC-side current loop PI controller is configured to be no lower than the dynamic response priority of the speed loop PI controller.

6. A motor control system for engineering machinery, characterized in that, include: The main controller is used to determine the total allowable current value of the DC side of the vehicle based on the fuse current of the battery fuse and the preset safety margin, obtain the real-time operating current of the oil pump motor controller, calculate the total current budget of all travel motor controllers based on the total allowable current value and the real-time operating current of the oil pump motor controller, allocate the corresponding DC side current limit value of each travel motor controller according to the total current budget, and send it to the corresponding travel motor controller. The oil pump motor controller is used to report its real-time operating current to the main controller. The walking motor controller is used to receive the corresponding DC-side current limit value and control the output torque according to the DC-side current limit value.

7. The motor control system for engineering machinery according to claim 6, characterized in that, The main controller calculates the total current budget for all walking motor controllers according to the following formula: I _walk_motor =I _limit_total -I _pump_motor ; Among them, I _walk_motor For the total current budget, I _limit_total I is the total allowable current value. _pump_motor This refers to the real-time operating current of the oil pump motor controller.

8. The motor control system for engineering machinery according to claim 6, characterized in that, The walking motor controller is specifically used for: The input current drawn from the DC bus is acquired in real time, and the DC side current limit value is used as the target current value. The input current drawn from the DC bus is used as the feedback current value and input to the DC side current loop PI controller so that the DC side current loop PI controller outputs a torque limit coefficient. The torque limit coefficient is in the range of (0, 1]. The actual motor speed is acquired in real time, and the actual motor speed is used as the feedback speed value and the reference speed is used as the target speed value. The input is then sent to the speed loop PI controller so that the speed loop PI controller outputs the original torque command. The final torque command is output based on the torque limit coefficient and the original torque command.

9. The motor control system for engineering machinery according to claim 8, characterized in that, The DC-side current loop PI controller is specifically used for: When the input current is less than or equal to the DC side current limit value, the output torque limit coefficient is 1; When the input current is greater than the DC-side current limit value, the value of the torque limit coefficient is reduced according to the deviation between the input current and the DC-side current limit value.

10. The motor control system for engineering machinery according to claim 8, characterized in that, The dynamic response priority of the DC-side current loop PI controller is configured to be no lower than the dynamic response priority of the speed loop PI controller.

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